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Aims Risk factors for asymptomatic echocardiographic abnormalities that predict symptomatic heart failure (HF) may provide insight into early mechanisms of HF pathogenesis. We examined risk factors associated with asymptomatic echocardiographic structural, systolic, and diastolic abnormalities, separately and in combination, and interactions between risk factors, in the prospective community‐based SCReening Evaluation of the Evolution of New HF (SCREEN‐HF) Study cohort of 3190 participants at increased risk of cardiovascular disease. Methods and results Inclusion criteria were age ≥ 60 years with one or more of hypertension, diabetes, ischaemic heart disease, valvular heart disease, abnormal heart rhythm, cerebrovascular disease, or renal impairment. Exclusion criteria were known HF, ejection fraction mild valve abnormality. Structural, systolic, and diastolic echocardiographic abnormalities were defined according to the Atherosclerosis Risk in Communities study criteria, and risk factors for asymptomatic structural, systolic, and diastolic abnormalities were identified using logistic regression analysis. In multivariable analysis, increased body mass index (BMI), non‐steroidal anti‐inflammatory drug therapy, and alcohol intake were risk factors for isolated structural abnormality, whereas male gender, increased heart rate, atrial fibrillation (AF), angiotensin‐converting enzyme inhibitor therapy, and obstructive sleep apnoea were associated with a lower risk. Moreover, male gender, smoking, increased systolic blood pressure, and physical inactivity were risk factors for isolated systolic abnormality, whereas increased pulse pressure and antihypertensive therapy were associated with a lower risk. Furthermore, increased age, blood pressure, amino‐terminal pro‐B‐type natriuretic peptide level, and warfarin therapy (associated with AF) were risk factors for isolated diastolic abnormality, whereas increased heart rate and triglyceride level (associated with BMI) were associated with a lower risk. The association of increased heart rate with lower risk of structural and diastolic abnormalities was independent of β‐blocker therapy. Interactions between risk factors differed for structural, systolic, and diastolic abnormalities. Conclusions The different risk factors for asymptomatic structural, systolic, and diastolic abnormalities that predict symptomatic HF, and the interactions between risk factors, illustrate how these structural, systolic, and diastolic abnormalities represent unique trajectories that lead to symptomatic HF. Improved understanding of these trajectories may assist in the design of HF prevention strategies.

Aim Heart failure (HF) incidence increases markedly with age. We examined age‐associated longitudinal change in cardiac structure and function, and their prediction by age and cardiovascular disease (CVD) risk factors, in a community‐based cohort aged ≥60 years at increased CVD risk but without HF. Methods and results CVD risk factors were recorded in 3065 participants who underwent a baseline echocardiographic examination, of whom 2358 attended a follow‐up examination 3.8 [median, inter‐quartile range (IQR) 3.5, 4.2] years later. Median age was 71 (IQR 67, 76) years and 55% of participants were male. Age was associated with longitudinal increase in left ventricular (LV) mass index (LVMI); decrease in LV volumes; increase in LV ejection fraction; decrease in mitral annular systolic velocity; decrease in diastolic function (decreased mitral early diastolic annular velocity (e′); and increase in left atrial volume index, mitral peak early diastolic flow velocity (E)/e′ ratio, and tricuspid regurgitant velocity (TRVmax) in men and women, except for TRVmax in men). In multivariable analysis, longitudinal increase in LVMI was explained by CVD risk factors alone, whereas age, together with CVD risk factors, independently predicted longitudinal change in all other echocardiographic parameters. CVD risk factors were differentially associated with longitudinal change in different echocardiographic parameters. Conclusions Whereas the increase in LVMI with age was explained by CVD risk factors alone, age, together with risk factors, independently predicted longitudinal change in all other echocardiographic parameters, providing evidence for age‐specific mechanisms of change in cardiac structure and function as people age. Age‐associated change in LVMI, LV volumes, and diastolic function resembled what might be expected for the evolution of HF with preserved ejection fraction. Given the differential association of different CVD risk factors with longitudinal change in different echocardiographic parameters, therapies aimed at attenuation of age‐associated change in cardiac structure and function, and HF evolution, will likely need to address multiple CVD risk factors.

A better understanding of the relationship between cardiovascular disease risk factors and quality of life (QoL) in older age is needed to inform development of risk reduction strategies. This cross-sectional study investigated the association of QoL with health-related behaviours in older adults at risk of heart failure.Older adults (N = 328) at risk of heart failure residing in Melbourne, Australia, provided data on QoL and health-related behaviours including physical activity, diet, smoking and alcohol consumption. Multiple linear regression modelling was used to examine associations between health-related behaviours, QoL and its constituent domains. After adjustment for age, gender, body mass index and comorbidities, current smoking was found to have a negative association with the mental component score (MCS) of QoL (β = -0.174, p ≤ 0.01), with a positive association seen between MCS and physical activity (β = 0.130, p = 0.01). Current alcohol use had a positive association with the physical component score (PCS) (β = 0.120, p = 0.02) and saturated fat intake consumption had a negative association with the physical functioning domain of QoL (β = -0.105, p = 0.03) but was not associated with either PCS or MCS.Engagement of older adults at increased cardiovascular risk with behavioural risk factor modification using QoL as a driver of change may offer new opportunities to promote healthy ageing. Development of such strategies should consider that for some behaviours which are cardiovascular risk factors (alcohol intake, in particular), the positive association to QoL is complicated and needs further deliberation.

Aims We investigated whether addition of diastolic dysfunction (DD) and longitudinal strain (LS) to Stage B heart failure (SBHF) criteria (structural or systolic abnormality) improves prediction of symptomatic HF in participants of the SCReening Evaluation of the Evolution of New Heart Failure study, a self‐selected population at increased cardiovascular disease risk recruited from members of a health insurance fund in Melbourne and Shepparton, Australia. Both American Society of Echocardiography and European Association of Cardiovascular Imaging (ASE/EACVI) criteria and age‐specific Atherosclerosis Risk in Communities (ARIC) study criteria, for SBHF and DD, and ARIC criteria for abnormal LS, were examined. Methods and results Inclusion criteria were age ≥60 years with one or more of self‐reported ischaemic or other heart disease, irregular or rapid heart rhythm, cerebrovascular disease, renal impairment, or treatment for hypertension or diabetes for ≥2 years. Exclusion criteria were known HF, or ejection fraction mild valve abnormality detected on previous echocardiography or other imaging. Echocardiography was performed in 3190 participants who were followed for a median of 3.9 (interquartile range: 3.4, 4.5) years after echocardiography. Symptomatic HF was diagnosed in 139 participants at a median of 3.1 (interquartile range: 2.1, 3.9) years after echocardiography. ARIC structural, systolic, and diastolic abnormalities predicted HF in univariate and multivariable proportional hazards analyses, whereas ASE/EACVI structural and systolic, but not diastolic, abnormalities predicted HF. ARIC and ASE/EACVI SBHF criteria predicted HF with sensitivities of 81% and 55%, specificities of 39% and 76%, and C statistics of 0.60 (95% confidence interval: 0.57, 0.64) and 0.66 (0.61, 0.71), respectively. Adding ARIC DD to SBHF increased sensitivity to 94% with specificity of 24% and C statistic of 0.59 (0.57, 0.61), whereas addition of ASE/EACVI DD to SBHF increased sensitivity to 97% but reduced specificity to 9% and the C statistic to 0.52 (0.50, 0.54, P

Background Given the age-related decline in glomerular filtration rate (GFR) in healthy individuals, we examined the association of all-cause death or cardiovascular event with the Kidney age - Chronological age Difference (KCD) score, whereby an individual’s kidney age is estimated from their estimated GFR (eGFR) and the age-dependent eGFR decline reported for healthy living potential kidney donors. Methods We examined the association between death or cardiovascular event and KCD score, age-dependent stepped eGFR criteria (eGFRstep), and eGFR 2 (eGFR60) in a community-based high cardiovascular risk cohort of 3837 individuals aged ≥60 (median 70, interquartile range 65, 75) years, followed for a median of 5.6 years. Results In proportional hazards analysis, KCD score ≥ 20 years (KCD20) was associated with increased risk of death or cardiovascular event in unadjusted analysis and after adjustment for age, sex and cardiovascular risk factors. Addition of KCD20, eGFRstep or eGFR60 to a cardiovascular risk factor model did not improve area under the curve for identification of individuals who experienced death or cardiovascular event in receiver operating characteristic curve analysis. However, addition of KCD20 or eGFR60, but not eGFRstep, to a cardiovascular risk factor model improved net reclassification and integrated discrimination. KCD20 identified individuals who experienced death or cardiovascular event with greater sensitivity than eGFRstep for all participants, and with greater sensitivity than eGFR60 for participants aged 60–69 years, with similar sensitivities for men and women. Conclusions In this high cardiovascular risk cohort aged ≥60 years, the KCD score provided an age-adapted measure of kidney function that may assist patient education, and KCD20 provided an age-adapted criterion of eGFR-related increased risk of death or cardiovascular event. Further studies that include the full age spectrum are required to examine the optimal KCD score cut point that identifies increased risk of death or cardiovascular event, and kidney events, associated with impaired kidney function, and whether the optimal KCD score cut point is similar for men and women. Trial registration ClinicalTrials.gov NCT00400257, NCT00604006, and NCT01581827.

Summary Background Mechanical ventilation in intensive care for 48 h or longer is associated with the acute respiratory distress syndrome (ARDS), which might be present at the time ventilatory support is instituted or develop afterwards, predominantly during the first 5 days. Survivors of prolonged mechanical ventilation and ARDS are at risk of considerably impaired physical function that can persist for years. An early pathogenic mechanism of lung injury in mechanically ventilated, critically ill patients is inflammation-induced pulmonary fibrin deposition, leading to thrombosis of the microvasculature and hyaline membrane formation in the air sacs. The main aim of this study was to determine if nebulised heparin, which targets fibrin deposition, would limit lung injury and thereby accelerate recovery of physical function in patients with or at risk of ARDS. Methods The Can Heparin Administration Reduce Lung Injury (CHARLI) study was an investigator-initiated, multicentre, double-blind, randomised phase 3 trial across nine hospitals in Australia. Adult intensive care patients on invasive ventilation, with impaired oxygenation defined by a PaO2/FiO2 ratio of less than 300, and with the expectation of invasive ventilation beyond the next calendar day were recruited. Key exclusion criteria were heparin allergy, pulmonary bleeding, and platelet count less than 50 X 109/L. Patients were randomly assigned 1:1, with stratification by site and using blocks of variable size and random seed, via a web-based system, to either unfractionated heparin sodium 25 000 IU in 5 mL or identical placebo (sodium chloride 0·9% 5 mL), administered using a vibrating mesh membrane nebuliser every 6 h to day 10 while invasively ventilated. Patients, clinicians, and investigators were masked to treatment allocation. The primary outcome was the Short Form 36 Health Survey Physical Function Score (out of 100) of survivors at day 60. Prespecified secondary outcomes, which are exploratory, included development of ARDS to day 5 among at-risk patients, deterioration of the Murray Lung Injury Score (MLIS) to day 5, mortality at day 60, residence of survivors at day 60, and serious adverse events. Analyses followed the intention-to-treat principle. There was no imputation of missing data. The trial is registered with the Australian and New Zealand Clinical Trials Register, number ACTRN12612000418875 . Findings Between Sept 4, 2012, and Aug 23, 2018, 256 patients were randomised. Final follow-up was on Feb 25, 2019. We excluded three patients who revoked consent and one ineligible participant who received no intervention. Of 252 patients included in data analysis, the mean age was 58 years (SD 15), 157 (62%) were men, and 118 (47%) had ARDS. 128 (51%) patients were assigned to the heparin group and 124 (49%) to the placebo group, all of whom received their assigned intervention. Survivors in the heparin group (n=97) had similar SF-36 Physical Function Scores at day 60 compared to the placebo group (n=94; mean 53·6 [SD 31·6] vs 48·7 [35·7]; difference 4·9 [95% CI −4·8 to 14·5]; p=0·32). Compared with the placebo group, the heparin group had fewer cases of ARDS develop to day 5 among the at-risk patients (nine [15%] of 62 patients vs 21 [30%] of 71 patients; hazard ratio 0·46 [95% CI 0·22 to 0·98]; p=0·0431), less deterioration of the MLIS to day 5 (difference −0·14 [–0·26 to −0·02]; p=0·0215), similar day 60 mortality (23 [18%] of 127 patients vs 18 [15%] of 123 patients; odds ratio [OR] 1·29 [95% CI 0·66 to 2·53]; p=0·46), and more day 60 survivors at home (86 [87%] of 99 patients vs 73 [73%] of 100 patients; OR 2·45 [1·18 to 5·08]; p=0·0165). A similar number of serious adverse events occurred in each group (seven [5%] of 128 patients in the heparin group vs three [2%] of 124 patients in the placebo group; OR 2·33 [0·59 to 9·24]; p=0·23), which were a transient increase in airway pressure during nebulisation (n=3 in the heparin group), major non-pulmonary bleeding (n=2 in each group), haemoptysis (n=1 in the heparin group), tracheotomy site bleeding (n=1 in the heparin group), and hypoxaemia during nebulisation (n=1 in the placebo group). Interpretation In patients with or at risk of ARDS, nebulised heparin did not improve self-reported performance of daily physical activities, but was well tolerated and exploratory outcomes suggest less progression of lung injury and earlier return home. Further research is justified to establish if nebulised heparin accelerates recovery in those who have or are at risk of ARDS. Funding Rowe Family Foundation, TR and RB Ditchfield Medical Research Endowment Fund, Patricia Madigan Charitable Trust, and The J and R McGauran Trust Fund.

Objectives Mis-reporting is common in dietary assessment, leading to misinterpretation of disease risk and could be important in older adults with increased chronic disease risk. This study investigated the prevalence and characteristics of mis-reporting among older adults and its association with health outcomes including quality of life (QoL). Methods The study was conducted in 335 community-dwelling older adults at increased risk for cardiovascular disease, participating in the SCReening Evaluation of the Evolution of New Heart Failure Study dietary substudy. Diet was assessed using 4-day weighed food diaries, QoL measured through Short Form 36, and physical activity assessed using the European Prospective Investigation into Cancer and Nutrition physical activity questionnaire. Dietary mis-reporting was defined based on Goldberg cutoffs, using individual physical activity levels. Odds ratios were determined to establish associations between mis-reporting and health outcomes. Results The prevalence of mis-reporting among older adults was 49.3%, with 44.5% of women mis-reporting their energy intake. The study found under-reporting of energy to be associated with body mass index, specifically being overweight (odds ratio: 3.08; 95% confidence interval [CI], 1.54–6.15) and obese (odds ratio: 6.60; 95% CI, 3.05–4.26), as well as physical inactivity (odds ratio: 0.24; 95% CI, 0.14–0.43). Only physical inactivity predicted over-reporting of dietary intake (odds ratio: 7.52; 95% CI, 1.57–36.0). Conclusions Dietary under-reporting was associated with being overweight, obese, and physically inactive in addition to the absence of comorbidities, reinforcing the need for further research in older adults to factor in dietary mis-reporting for meaningful diet–disease relationship analyses.

Renal ischemia-reperfusion injury (IRI) leads to acute kidney injury and renal fibrosis. CD39 is a key purinergic enzyme in the hydrolysis of adenosine triphosphate (ATP) and increased CD39 enzymatic activity protects from acute IRI but its effect on renal fibrosis is not known.Using a mouse model of unilateral renal IRI, the effects of increased CD39 activity (using soluble apyrase and mice expressing human CD39 transgene) on acute and chronic renal outcomes were examined. Nucleotide (ATP, adenosine diphosphate, adenosine monophosphate) and nucleoside (adenosine and inosine) levels were quantified by high-performance liquid chromatography. Soluble apyrase reduced acute renal injury at 24 hours and renal fibrosis at 4 weeks post-IRI, compared with vehicle-treated mice.Soluble apyrase reduced renal ATP, adenosine diphosphate, and adenosine monophosphate, but not adenosine levels, during ischemia. In comparison with wild-type littermates, hCD39 transgenic mice were protected from acute renal injury at 24 hours, but had increased renal fibrosis at 4 weeks post-IRI. hCD39 transgene expression was localized to the vascular endothelium at baseline and did not affect total renal nucleotide and nucleoside levels during ischemia. However, hCD39 transgene was more widespread at 4 weeks post-IRI and was associated with higher renal adenosine levels at 4 weeks post-IRI compared with wild-type littermates.A single dose of apyrase administration before IRI protects from both acute and chronic renal injuries and may have clinical application in protection from ischemic-induced renal injury. Furthermore, transgenic expression of hCD39 is associated with increased renal fibrosis after ischemia.

Background Body mass index †Deceased. (BMI) is a risk factor for heart failure with preserved ejection fraction (HFpEF). Design We investigated the threshold BMI and sex-specific waist circumference associated with increased HFpEF incidence in the SCReening Evaluation of the Evolution of New Heart Failure (SCREEN-HF) study, a cohort study of a community-based population at increased cardiovascular disease risk. Methods Inclusion criteria were age ≥60 years with one or more of self-reported hypertension, diabetes, heart disease, abnormal heart rhythm, cerebrovascular disease or renal impairment. Exclusion criteria were known heart failure, ejection fraction Results HFpEF incidence rates were higher for BMI ≥27.5 kg/m2 than for BMI 2, and for waist circumference >100 cm (men) or > 90 cm (women) than for waist circumference ≤94 cm (men) or ≤ 83 cm (women) in Poisson regression analysis. Semiparametric proportional hazards analyses confirmed these BMI and waist circumference thresholds, and exceeding these thresholds was associated with an attributable risk of HFpEF of 44–49%. Conclusions Both central obesity and overweight were associated with increased HFpEF incidence. Although a randomised trial of weight control would be necessary to establish a causal relationship between obesity/overweight and HFpEF incidence, these data suggest that maintenance of BMI and waist circumference below these thresholds in a community similar to that of the SCREEN-HF cohort may reduce the HFpEF incidence rate by as much as 50%.

Neprilysin has a major role in both the generation and degradation of bioactive peptides. LCZ696 (valsartan/sacubitril, Entresto), the first of the new ARNI (dual-acting angiotensin-receptor-neprilysin inhibitor) drug class, contains equimolar amounts of valsartan, an angiotensin-receptor blocker, and sacubitril, a prodrug for the neprilysin inhibitor LBQ657. LCZ696 reduced blood pressure more than valsartan alone in patients with hypertension. In the PARADIGM-HF study, LCZ696 was superior to the angiotensin-converting enzyme inhibitor enalapril for the treatment of heart failure with reduced ejection fraction, and LCZ696 was approved by the FDA for this purpose in 2015. This approval was the first for chronic neprilysin inhibition. The many peptides metabolized by neprilysin suggest many potential consequences of chronic neprilysin inhibitor therapy, both beneficial and adverse. Moreover, LBQ657 might inhibit enzymes other than neprilysin. Chronic neprilysin inhibition might have an effect on angio-oedema, bronchial reactivity, inflammation, and cancer, and might predispose to polyneuropathy. Additionally, inhibition of neprilysin metabolism of amyloid-β peptides might have an effect on Alzheimer disease, age-related macular degeneration, and cerebral amyloid angiopathy. Much of the evidence for possible adverse consequences of chronic neprilysin inhibition comes from studies in animal models, and the relevance of this evidence to humans is unknown. This Review summarizes current knowledge of neprilysin function and possible consequences of chronic neprilysin inhibition that indicate a need for vigilance in the use of neprilysin inhibitor therapy.

Aims We investigated which serum amino-terminal pro-B-type-natriuretic peptide (NT-proBNP) levels inform heart failure (HF) risk in a community-based population at increased cardiovascular disease (CVD) risk. Methods and results Inclusion criteria were age ≥ 60 years with one or more of self-reported hypertension, diabetes, heart disease, abnormal heart rhythm, cerebrovascular disease, or renal impairment. Exclusion criteria were known HF, ejection fraction (EF) 76% and specificities of 47–69% for 5-year prediction of total HF in men and women in all three age groups. Sensitivities were ≥ 75% in most subgroups according to body mass index, estimated glomerular filtration rate, and the presence or absence of atrial fibrillation, pacemaker, or CVD, and for the prediction of HFpEF, HFrEF and VHF. Conclusion Age-specific serum NT-proBNP levels inform prognosis, and hence therapeutic decisions, regarding HF risk in individuals at increased CVD risk.

Caillon et al1 report that angiotensin (Ang) II infusion increased blood pressure, decreased endothelial function, and increased γδ T-cell numbers and activation in the spleen of mice, and that the blood pressure and endothelial responses were abrogated by Tcrδ gene knockout and blunted by γδ T-cell depletion with an anti–T-cell receptor (TCR) γδ antibody. They also report that systolic blood pressure was associated with whole blood TCR γ constant region gene expression in a cohort of patients who had undergone coronary angiography. They conclude that γδ T cells mediate Ang II–induced blood pressure elevation, vascular injury, and T-cell activation in mice, and speculate that γδ T …

Effective management of cardiovascular and chronic kidney disease risk factors offers longer, healthier lives and savings in healthcare.To examine risk factor management in participants of the SCReening Evaluation of the Evolution of New Heart Failure study, a self-selected population at increased cardiovascular disease risk recruited from members of a health insurance fund in Melbourne and Shepparton, Australia.Inclusion criteria were age ≥ 60 years with one or more self-reported ischaemic or other heart diseases, irregular or rapid heart rhythm, cerebrovascular disease, renal impairment or treatment for hypertension or diabetes for ≥2 years. Exclusion criteria were known heart failure or cardiac abnormality on echocardiography or other imaging. Medical history, clinical examination, full blood examination and biochemistry (without lipids and glycated haemoglobin (HbA1c)) were performed for 3847 participants on enrolment, and blood pressure, lipids and HbA1c were measured 1-2 years after enrolment for 3203 participants.Despite 99% of 3294 participants with hypertension receiving antihypertensive medication, half had blood pressures140/90 mmHg. Approximately 77% of participants were overweight or obese, with one third being obese. Additionally, 74% of participants at high cardiovascular disease risk had low-density lipoprotein cholesterol levels ≥2 mmol/L, one third of diabetic participants had HbA1c7%, 22% had an estimated glomerular filtration rate60 mL/min/1.73mThis population demonstrated substantial potential to reduce cardiovascular and renal morbidity and mortality and healthcare costs through more effective management of modifiable risk factors.

Background There is debate whether the J-curve relationship between cardiac event risk and DBP is because of inherent cardiac risk or is a consequence of blood pressure (BP) lowering therapy. Methods We examined the association between the cardiovascular risk marker amino-terminal-pro-B-type natriuretic peptide (NT-proBNP) and DBP in 1781 women and 2211 men aged at least 60 years with one or more cardiovascular risk factors; exclusion criteria were known heart failure or cardiac abnormality on a cardiac imaging study. Results The lowest median serum NT-proBNP levels were for DBP 85-89 mmHg for both women and men. DBP less than 70 mmHg in women and less than 80 mmHg in men was associated with higher NT-proBNP levels than the levels at DBP 85-89 mmHg, and this relationship was present for those with SBP equal to or less than 140 and SBP greater than 140 mmHg. In conditional logistic regression models, the association of elevated NT-proBNP levels with low DBP in women was no longer statistically significant after adjustment for age, ischaemic heart disease (IHD), pulse rate, atrial fibrillation, haemoglobin and glomerular filtration rate, whereas the association in men was no longer statistically significant after adjustment for age and IHD. By contrast, the association between elevated NT-proBNP levels and low DBP remained statistically significant after adjustment for the number of antihypertensive drug classes alone or together with all antihypertensive drugs, including β-blocker therapy. Conclusion There was a J-curve relationship between the cardiovascular risk marker NT-proBNP and DBP that was explained by the clinical variables and not by the BP-lowering therapy.

We assessed left ventricular dysfunction in a population at high risk for heart failure (HF), and explored associations between ventricular function, HF risk factors and NT-proB natriuretic peptide (NT-proBNP).3550 subjects at high risk for incident HF (≥60 years plus ≥1 HF risk factor), but without pre-existing HF or left ventricular dysfunction, were recruited. Anthropomorphic data, medical history and blood for NT-proBNP were collected. Participants at highest risk (n = 664) (NT-proBNP highest quintile;30.0 pmol/L) and a sample (n = 51) from the lowest NT-proBNP quintile underwent echocardiography. Participants in the highest NT-proBNP quintile, compared to the lowest, were older (74 years vs. 67 years; p0.001) and more likely to have coronary artery disease, stroke or renal impairment. In the top NT-proBNP quintile (n = 664), left ventricular systolic impairment was observed in 6.6% (95% CI: 4 to 8%) of participants and was associated with male gender, coronary artery disease, hypertension and NT-proBNP. At least moderate diastolic dysfunction was observed in 24% (95% CI 20 to 27%) of participants and was associated with diabetes and NT-proBNP. In this high risk population, NT-proBNP was associated with left ventricular systolic impairment (p0.001) and moderate to severe diastolic dysfunction (p0.001) after adjustment for age, gender, coronary artery disease, diabetes, hypertension and obesity.A high burden of ventricular dysfunction was observed in this high risk group. Combining NT-proBNP and HF risk factors may identify those with ventricular dysfunction. This would allow resources to be focused on those at greatest risk of progression to overt HF.

Background Myocardial microvascular dysfunction has been implicated in the pathogenesis of myocardial infarction (MI). We tested the hypothesis that patients with MI have lower microvasculature density in myocardium remote from the site of infarction than patients with similar extent of coronary artery disease (CAD) without MI and examined the relationship between myocardial capillary length density and plasma levels of angiogenesis-related biomarkers. Methods We analyzed biopsies from non-ischemic left ventricular (LV) myocardium and measured plasma levels of angiogenesis-related biomarkers in patients undergoing coronary artery bypass graft surgery, 57 without previous MI (no-MI) and 27 with recent non-ST-segment-elevation MI (NSTEMI). Comparison was made with biopsies from 31 aortic stenosis (AS) patients and 6 patients with "normal" LV without CAD. Results Myocardial microvascular density of NSTEMI patients was approximately half the density of no-MI patients, and similar to AS patients. Whereas the reduced microvascular density of AS patients was accounted for by their cardiomyocyte hypertrophy, this was not the case for NSTEMI patients, who had higher diffusion radius/cardiomyocyte width ratio than no-MI, "normal" LV, and AS patients. NSTEMI patients had lower plasma levels of carboxymethyl lysine and low molecular weight fluorophores, higher vascular endothelial growth factor (VEGF) receptor-1/VEGF-A ratio, and higher endostatin and hepatocyte growth factor levels than no-MI patients. Conclusions Recent MI was associated with reduced microvasculature density in myocardium remote from the site of infarction and alteration in plasma levels of angiogenesis-related biomarkers.

Impaired diastolic function is associated with increased morbidity and mortality, but antecedents and predictors of progression to heart failure (HF) are not well understood. We examined associations between NT-proBNP, HF risk factors, and diastolic function in a population at high risk for incident HF.A total of 3550 subjects at high risk for incident HF (≥60 years plus ≥1 HF risk factor), but without pre-existing HF or LV dysfunction were recruited. Participants at highest risk (n = 664) (NT-proBNP in the highest quintile254 pg/mL) underwent echocardiography. Moderate or severe diastolic dysfunction was observed in 25% [95% confidence interval (CI) 21-29%] of participants. Age (P = 0.001), male gender (P = 0.03), diabetes (P = 0.03), and NT-proBNP (P = 0.002) were associated with severity of diastolic dysfunction after adjustment for HF risk factors and LVEF. In regression analysis, log-transformed NT-proBNP was also associated with LV mass index (P = 0.05), left atrial size (P0.0001), and Doppler ratio of the mitral valve E/e' (P = 0.001). Multiple HF risk factors were present in the majority of participants (70%), but no association was observed between diastolic dysfunction and the number of risk factors reported (P = 0.3).Diastolic dysfunction was observed in one in four of these high risk subjects (≥ 60 years, HF risk factor, NT-proBNP254 pg/mL). NT-proBNP, age and diabetes were strongly associated with severity of diastolic dysfunction, whereas other HF risk factors and LVEF were not. More targeted surveillance using a combination of risk factors and biomarkers may improve identification of those at great risk of incident HF.

Objective The aim of the present study was to determine whether asymptomatic heart failure (HF) in the workplace is subject to the health worker effect, making screening using conventional risk factors combined with a cardiac biomarker, namely N-terminal pro B-type natriuretic peptide (NT-proBNP), as useful as in the general population. Methods Between June 2007 and December 2009 a ‘well’ population deemed at high risk for development of HF was identified through health insurance records. Blood was collected from volunteer participants for analysis of urea, electrolytes and creatinine, a full blood count and NT-proBNP. An echocardiogram was performed on selected participants based on high NT-proBNP concentrations. Results The mean left ventricular ejection fraction (LVEF) was significantly reduced in participants with the highest compared with the lowest NT-proBNP quintile. In multivariate analysis, log-transformed NT-proBNP was independently associated with impaired LVEF and with moderate to severe diastolic dysfunction after adjustment for age, sex, coronary artery disease, diabetes, hypertension and obesity. Conclusions A large burden of asymptomatic left ventricular dysfunction (AVLD) was observed in subjects aged 60 and over with plasma NT-proBNP in the top quintile that was independent of conventional risk factors and work status. HWE does not appear to operate in AVLD. NT-proBNP testing in a population with HF risk factors may cost-effectively identify those at greatest risk of developing HF in a working population and facilitate early diagnosis, treatment and maintenance of work capacity. What is known about the topic? Chronic heart failure (CHF) has several causes, the most common being hypertension and coronary ischaemia. CHF is a major health problem of increasing prevalence that severely impacts quality of life, shortens lives and reduces worker productivity. It is often not diagnosed early enough to take full advantage of ameliorating medication. What does this paper add? Population screening for CHF is not currently advocated. This may be because conventional risk factors must be used in combination and there is no useful biomarker available. Yet evidence (SOLVD (Studies of Left Ventricular Dysfunction trials) recommends early diagnosis. We believe the work place is an area of potential screening where there is little supporting evidence. This paper provides evidence that the biomarker NT-proBNP is a useful new tool that improves cost-effectiveness of screening in a selected population. Specifically, the paper recommends CHF screening in the population with the highest potential health gain (i.e. the working population) by the sector with the highest economic gain (i.e. employers). What are the implications for practitioners? The paper presents important health screening recommendations for medical and health and safety practitioners within a selected population of workers. We feel practitioners should consider screening for incipient heart failure, particularly within Australia’s working population, to save lives, provide economic benefit and extend working longevity.

Heart failure (HF) continues to grow as a cause of morbidity and mortality in our community and presents a significant public health problem, predominantly in individuals ≥65 years of age. Early intervention in asymptomatic HF subjects (Stage A/B) at risk of progression to symptomatic HF (Stage C/D) may provide an opportunity to halt this epidemic. The ability of cardiac imaging to assess cardiac structure and function permits early identification of those at increased risk of developing symptomatic HF. Systolic, diastolic, and structural left ventricular parameters each predict symptomatic HF, but no single parameter has sufficient sensitivity for screening to identify individuals with Stage A/B HF who are at increased risk of disease progression. Transthoracic echocardiography (TTE) has the advantage over other imaging modalities in being able to measure systolic, diastolic, and structural left ventricular parameters, and it identified at least 1 abnormal parameter in >50% of individuals with Stage A/B HF ≥65 years of age. Moreover, identification of at least 1 abnormality according to TTE in individuals with Stage A/B HF ≥65 years of age had 72% to 82% sensitivity for detection of those who subsequently developed symptomatic HF. Therefore, a case can be made for cardiac imaging by using TTE for community-dwelling populations with Stage A/B HF ≥65 years of age to identify those with increased risk of symptomatic HF who can be offered preventative therapies. Further studies are required to determine the best strategy for identifying the risk of symptomatic HF in younger individuals.

Background and Purpose— Several prospective studies have shown significant associations between plasma fibrinogen, viscosity, C-reactive protein (CRP), fibrin d -dimer, or tissue plasminogen activator (tPA) antigen and the risk of primary cardiovascular events. Little has been published on the associations of these variables with recurrent stroke. We studied such associations in a nested case-control study derived from the Perindopril Protection Against Recurrent Stroke Study (PROGRESS). Methods— Nested case-control study of ischemic (n=472) and hemorrhagic (n=83) strokes occurring during a randomized, placebo-controlled multicenter trial of perindopril-based therapy in 6105 patients with a history of stroke or transient ischemic attack. Controls were matched for age, treatment group, sex, region, and most recent qualifying event at entry to the parent trial. Results— Fibrinogen and CRP were associated with an increased risk of recurrent ischemic stroke after accounting for the matching variables and adjusting for systolic blood pressure, smoking, peripheral vascular disease, and statin and antiplatelet therapy. The odds ratio for the last compared with the first third of fibrinogen was 1.34 (95% CI, 1.01 to 1.78) and for CRP was 1.39 (95% CI, 1.05 to 1.85). After additional adjustment for each other, these 2 odds ratios stayed virtually unchanged. Plasma viscosity, tPA, and d -dimer showed no relationship with recurrent ischemic stroke, although tPA was significant for lacunar and large artery subtypes. Although each of these variables showed a negative relationship with recurrent hemorrhagic stroke, none of these relationships achieved statistical significance. Conclusions— Fibrinogen and CRP are risk predictors for ischemic but not hemorrhagic stroke, independent of potential confounders.

B-type natriuretic peptide (BNP) and C-reactive protein (CRP) are elevated in persons at risk for congestive heart failure (CHF). However, limited data are available directly comparing BNP-related peptides and CRP in persons at risk of CHF. To evaluate amino terminal–pro-BNP (NT-proBNP) and CRP, separately and together, for assessment of risk of CHF, we performed a nested case-control study of the 6105 participants of the Perindopril pROtection aGainst REcurrent Stroke Study (PROGRESS), a placebo-controlled study of a perindopril-based blood pressure–lowering regimen among individuals with previous stroke or transient ischemic attack (TIA). Each of 258 subjects who developed CHF resulting in death, hospitalization, or withdrawal of randomized therapy during a mean follow-up of 3.9 years was matched to 1 to 3 control subjects. NT-proBNP and CRP predicted CHF; the odds ratio for subjects in the highest compared with the lowest quarter was 4.5 (95% confidence interval, 2.7 to 7.5) for NT-proBNP and 2.9 (confidence interval, 1.9 to 4.7) for CRP, and each remained a predictor of CHF after adjustment for all other predictors. Screening for both markers provided better prognostic information than screening for either alone. Elevation of NT-proBNP above 50 pmol/L and CRP above 0.84 mg/L predicted CHF with sensitivity of 64% and specificity of 66%. NT-proBNP and CRP predicted CHF in subjects receiving perindopril-based therapy. We conclude that NT-proBNP and CRP are independent predictors of CHF risk after stroke or TIA. Moreover, NT-proBNP and CRP may be markers of mechanisms of CHF pathogenesis distinct from those responsive to angiotensin-converting enzyme inhibitor–based therapy.

OBJECTIVE: The plasma amino-terminal-pro-B-type natriuretic peptide (NT-proBNP) level predicted congestive heart failure, myocardial infarction, and ischaemic stroke in participants of the Perindopril Protection Against Recurrent Stroke Study (PROGRESS), a placebo-controlled study of the effects of blood pressure lowering on cardiovascular events among individuals with cerebrovascular disease. Active treatment comprised a flexible regimen based on perindopril, with the addition of indapamide at the discretion of treating physicians. Active treatment reduced cardiovascular events, and we therefore investigated whether active treatment modified NT-proBNP and other cardiovascular risk factors. METHODS: We measured NT-proBNP and other cardiovascular risk factors at randomization and after 13 months of therapy in a subset of 357 PROGRESS participants. RESULTS: Baseline systolic and pulse pressures were higher in individuals with elevated baseline NT-proBNP levels. In comparison with placebo, active treatment reduced the blood pressure and NT-proBNP levels, and increased renin levels. Reduction of NT-proBNP levels by active treatment was most evident in individuals with baseline NT-proBNP levels in the highest quarter (> 26 pmol/l), with a median reduction of 16 pmol/l (interquartile range 0-51 pmol/l, P = 0.004), corresponding to a median decrease of 39% (interquartile range 0-69%). Active treatment reduced blood pressure similarly for individuals in each of the four quarters of baseline NT-proBNP. Active therapy had no effect on plasma lipid, C-reactive protein, homocysteine, or soluble vascular cell adhesion molecule 1 levels. CONCLUSION: We conclude that plasma NT-proBNP level, in addition to predicting cardiovascular risk, may provide a measure of risk reduction by blood pressure-lowering therapy.

The kallikrein kinin system has cardioprotective actions and mediates in part the cardioprotection produced by angiotensin converting enzyme inhibitors and angiotensin type 1 receptor blockers. Additional approaches to exploit the cardioprotective effects of the kallikrein kinin system include the administration of tissue kallikrein and kinin receptor agonists. The renin inhibitor aliskiren was recently shown to increase cardiac tissue kallikrein expression and bradykinin levels, and to reduce myocardial ischemia-reperfusion injury by bradykinin B2 receptor- and angiotensin AT2 receptor-mediated mechanisms. Thus, aliskiren represents a prototype drug for the modulation of tissue kallikrein expression for therapeutic benefit.

We measured components of the kallikrein- kinin system in human type 2 diabetes mellitus and the effects of statin therapy on the circulating kallikrein-kinin system.Circulating levels of bradykinin and kallidin peptides, and high and low molecular weight kininogens, as well as plasma and tissue kallikrein, and kallistatin were measured in non-diabetic and diabetic patients before coronary artery bypass graft surgery. Tissue kallikrein levels in atrial tissue were examined by immunohistochemistry and atrial tissue kallikrein mRNA quantified.Plasma levels of tissue kallikrein were approximately 62% higher in diabetic than in non-diabetic patients (p=0.001), whereas no differences were seen in circulating levels of bradykinin and kallidin peptides, and high and low molecular weight kininogens, or in plasma kallikrein or kallistatin. Immunohistochemistry revealed a twofold increase in tissue kallikrein levels in atrial myocytes (p= 0.015), while tissue kallikrein mRNA levels were increased eightfold in atrial tissue of diabetic patients (p=0.014). Statin therapy did not change any variables of the circulating kallikrein-kinin system. Neither aspirin, calcium antagonists, beta blockers or long-acting nitrate therapies influenced any kallikrein-kinin system variable.Tissue kallikrein levels are increased in type 2 diabetes, whereas statin therapy does not modify the circulating kallikrein-kinin system. Cardiac tissue kallikrein may play a greater cardioprotective role in type 2 diabetic than in non-diabetic patients and contribute to the benefits of ACE inhibitor therapy in type 2 diabetic patients. However, our findings do not support a role for the kallikrein-kinin system in mediating the effects of statin therapy on endothelial function.

Over many decades, several attempts have been made to treat hypertension using a vaccination strategy to inhibit the renin-angiotensin system. Renin vaccination successfully inhibited renin activity and reduced blood pressure in animal models, but caused autoimmune disease of the kidney. By contrast, most previous studies of angiotensin vaccination failed to reduce blood pressure in animal models, despite producing high titers of antibodies that prevented the pressor response to exogenous angiotensins. Angiotensin vaccination is being revisited as a strategy for treating hypertension, in the hope that new conjugates of angiotensin I and angiotensin II will produce antibodies of sufficient titer and affinity to reduce blood pressure in patients with hypertension. A recent clinical study of angiotensin II vaccination provided some cause for optimism, but many hurdles remain before this strategy can compete with current oral medications for hypertension.

Background: Measurement of plasma renin is important for the clinical assessment of hypertensive patients. The most common methods for measuring plasma renin are the plasma renin activity (PRA) assay and the renin immunoassay. The clinical application of renin inhibitor therapy has thrown into focus the differences in information provided by activity assays and immunoassays for renin and prorenin measurement and has drawn attention to the need for precautions to ensure their accurate measurement.Content: Renin activity assays and immunoassays provide related but different information. Whereas activity assays measure only active renin, immunoassays measure both active and inhibited renin. Particular care must be taken in the collection and processing of blood samples and in the performance of these assays to avoid errors in renin measurement. Both activity assays and immunoassays are susceptible to renin overestimation due to prorenin activation. In addition, activity assays performed with peptidase inhibitors may overestimate the degree of inhibition of PRA by renin inhibitor therapy. Moreover, immunoassays may overestimate the reactive increase in plasma renin concentration in response to renin inhibitor therapy, owing to the inhibitor promoting conversion of prorenin to an open conformation that is recognized by renin immunoassays.Conclusions: The successful application of renin assays to patient care requires that the clinician and the clinical chemist understand the information provided by these assays and of the precautions necessary to ensure their accuracy.

Aliskiren (Tekturna or Rasilez) is an orally active renin inhibitor approved for the treatment of hypertension.1 As with inhibition of the renin-angiotensin system by angiotensin-converting enzyme inhibitors or type 1 angiotensin II (Ang II) receptor blockers, aliskiren therapy is accompanied by a reactive rise in plasma renin concentration, although in contrast to angiotensin-converting enzyme inhibitor and angiotensin receptor blocker therapy, aliskiren reduces enzymatic plasma renin activity (PRA). A direct comparison of aliskiren and angiotensin receptor blocker therapies in hypertensive patients showed differences in the magnitude of the reactive renin response.2,3 In 1 study, 300 mg/d of aliskiren and 320 mg/d of valsartan were similarly hypotensive, whereas plasma renin concentration was 2-fold higher during aliskiren therapy.3 In a second study, 150 mg/d of aliskiren and 150 mg/d of irbesartan were similarly hypotensive, whereas plasma renin concentration was 1.4-fold higher during aliskiren therapy.2,4 Moreover, the renin response to 300 mg of aliskiren was 1.6-fold higher than the response to 320 mg of valsartan in sodium-replete normotensive volunteers.5 Sealey and Laragh6 proposed that the exaggerated renin response may limit aliskiren’s ability to reduce blood pressure by counteracting the effect of renin inhibition on Ang II levels and may thereby account for the failure of 600 mg of aliskiren to reduce blood pressure at >300 mg of aliskiren. They also proposed the renin response to aliskiren therapy may paradoxically increase blood pressure in patients with a highly reactive renin concentration (renovascular, advanced, and malignant hypertension).6 Another concern expressed by several authors was the possible action of the increased renin concentrations on the putative renin receptor.2,7–10 How should the exaggerated renin response to aliskiren therapy be interpreted? Renin secretion is subject to tonic negative feedback inhibition by Ang II, and the reactive increase in renin concentration provides …

Background Prediction models are essential to the development of prediction rules that guide decision-making, and comparison of prediction models with and without an additional diagnostic or prognostic risk factor allows assessment of the value of the additional factor in risk prediction. However, the many different measures described to translate the information provided by a prediction model do not readily assist clinicians’ decision-making. Results The clinical utility (CU) curve is proposed as an alternative method of communication of information from a prediction model to the clinician. The CU curve is essentially a derivation of the ROC curve that has sensitivity on the y-axis and the number needed to capture one case (NNCOC) on the x-axis. It provides information about the relationship between sensitivity and false positive rate over the full range of prediction score thresholds, and it also indicates the proportion of the patient population with an absolute risk below the threshold for 100 % sensitivity that can therefore be classified as free of disease. Conclusions The CU curve is proposed as a means to assist the translation of model information to the clinician, in the hope that it will stimulate debate and, through refinement, assist the development of prediction rules with optimal clinical utility. Electronic supplementary material The online version of this article (doi:10.1186/s13104-016-2028-0) contains supplementary material, which is available to authorized users.

Duncan J CampbellSt. Vincent’s Institute of Medical Research and the Department of Medicine, University of Melbourne, St. Vincent’s Hospital, Fitzroy, Victoria, AustraliaBackground: Angiotensin-converting enzyme inhibitors (ACEI) have a well-established role in the prevention of cardiovascular events in hypertension, left ventricular dysfunction, and heart failure. More recently, ACEI have been shown to prevent cardiovascular events in individuals with increased cardiovascular risk, where hypertension, left ventricular dysfunction, or heart failure was not the primary indication for ACEI therapy.Objective: To review studies of the effects of the ACEI perindopril on cardiovascular events.Method: The EUROPA (European Trial on Reduction of Cardiac Events with Perindopril in Patients with Stable Coronary Artery Disease Study), PROGRESS (Perindopril Protection Against Recurrent Stroke Study), and ASCOT-BPLA (Anglo-Scandinavian Cardiac Outcomes Trial – Blood Pressure Lowering Arm) trials are reviewed.Results: Perindopril alone reduced cardiovascular events in subjects with stable coronary heart disease. Perindopril in combination with indapamide reduced cardiovascular events in subjects with cerebrovascular disease. Perindopril in combination with amlodipine reduced cardiovascular events in subjects with hypertension.Conclusion: Perindopril reduced cardiovascular events. The reduction of cardiovascular events by perindopril was in large part associated with reduction of blood pressure, and greater reduction in cardiovascular events was associated with greater reduction of blood pressure. Perindopril may need to be combined with other antihypertensive agents to maximize reduction of cardiovascular events.Keywords: Angiotensin-converting enzyme inhibitor, hypertension, coronary heart disease, stroke, myocardial infarction, heart failure

It has long been proposed that the renin-angiotensin system exerts a stimulatory influence on the sympathetic nervous system, including augmentation of central sympathetic outflow and presynaptic facilitation of norepinephrine release from sympathetic nerves. We tested this proposition in 19 patients with essential hypertension, evaluating whether the angiotensin receptor blockers (ARBs) eprosartan and losartan had identifiable antiadrenergic properties. This was done in a prospective, randomized, three-way placebo-controlled study of crossover design. Patients were randomized to 600 mg of eprosartan daily, 50 mg of losartan daily, or placebo. The treatment period was 4 wk, with 2-wk washout periods. Multiunit firing rates in efferent sympathetic nerves distributed to skeletal muscle vasculature (muscle sympathetic nerve activity, MSNA) were measured with microneurography, testing whether ARBs inhibit central sympathetic outflow. In parallel, isotope dilution methodology was used to measure whole body norepinephrine spillover to plasma. Mean blood pressure on placebo was 151/98 mmHg, with both ARBs causing reductions of approximately 11 mmHg systolic and 6 mmHg diastolic pressure, placebo corrected. Both MSNA [35 +/- 12 bursts/min (mean +/- SD) on placebo] and whole body norepinephrine spillover [366 +/- 247 ng/min] were unchanged by ARB administration, indicating that the ARBs did not materially inhibit central sympathetic outflow or act presynaptically to reduce norepinephrine release at existing rates of nerve firing. These findings contrast with the easily demonstrable reduction in sympathetic nervous activity produced by antihypertensive drugs of the imidazoline-binding class, which are known to act within the brain to inhibit sympathetic nervous outflow. We conclude that sympathetic nervous inhibition is not a major component of the blood pressure-lowering action of ARBs in essential hypertension.

BACKGROUND Angiotensin (Ang) II may enhance the influence of the sympathetic nervous system at various levels by facilitating norepinephrine (NE) release. We investigated whether such an interaction is evident in the human heart and whether it has an impact on left ventricular (LV) structure. METHODS AND RESULTS Ang I and Ang II concentrations were determined in arterial and coronary sinus (CS) plasma samples in a group of normotensive (n = 10) and hypertensive (n = 18) subjects. Total systemic and cardiac NE spillover was measured using isotope dilution methodology and LV structure by echocardiography. Arterial and CS concentrations of Ang I and Ang II were similar in both groups (Ang II CS, 5.8 +/- 4.0 versus 3.7 +/- 3.1 fmol/ml; P = not significant), as was the Ang II/Ang I ratio (CS, 0.56 +/- 0.17 versus 0.54 +/- 0.22 fmol/fmol; P = not significant). Total systemic (223 +/- 145 versus 374 +/- 149 ng/min; P < 0.05) and cardiac NE spillover (11.7 +/- 6.3 versus 19.4 +/- 10.5 ng/min; P < 0.05) were increased in hypertensive patients, as was LV mass index (LVMI) (86.7 +/- 14.7 versus 117.2 +/- 19.4 g/m; P < 0.001). LVMI correlated with cardiac NE spillover (r = 0.47; P < 0.02). No correlation was evident between CS Ang II and cardiac NE spillover (r = 0.001; P = not significant) or LVMI (r = -0.20; P = not significant). Arterial Ang II tended to correlate with total systemic NE spillover (r = 0.34; P = 0.081). When hypertensive subjects were divided into two groups with either high or low CS Ang II concentration, cardiac NE spillover and LVMI did not differ between the two groups. CONCLUSION These findings suggest a growth-promoting effect of increased cardiac sympathetic tone on cardiomyocytes in hypertensive patients, but do not support the notion of a significant role of Ang II for norepinephrine release and LV hypertrophy in the hypertensive human heart.

Obesity in humans is associated with lipid accumulation in skeletal muscle, insulin and leptin resistance, and type 2 diabetes. AMP-activated protein kinase (AMPK) is an important regulator of fatty acid (FA) metabolism in skeletal muscle. To address the hypothesis that lipid accumulation in skeletal muscle of obese subjects may be due to down-regulation of AMPK, we measured mRNA and protein levels of AMPK isoforms, AMPK1 and -2 activity, AMPK kinase activity, acetylcoenzyme A carboxylase (ACC) expression and phosphorylation, and FA metabolism in biopsies of rectus abdominus muscle from lean and obese women. We also examined the effect of 5-aminoimidazole-4-carboxamide riboside (AICAR) on AMPK activity and the effects of AICAR and leptin on FA metabolism. Skeletal muscle of obese subjects had increased total FA uptake and triglyceride esterification, and leptin failed to stimulate FA oxidation. However, AMPK mRNA and protein expression, AMPK1 and -2 activities, AMPK kinase activity, ACC phosphorylation, and FA oxidation were similar in lean and obese subjects. Moreover, AICAR increased AMPK2 activity, ACC phosphorylation, and palmitate oxidation to a similar degree in muscle from lean and obese subjects. We conclude that the abnormal lipid metabolism and leptin resistance of skeletal muscle of obese subjects is not due to down-regulation of AMPK. In addition, the similar stimulation by AICAR of AMPK in skeletal muscle of lean and obese subjects suggests that direct pharmacological activation of AMPK may be a therapeutic approach for stimulating FA oxidation in the treatment of human obesity. (J Clin Endocrinol Metab 89: 4575– 4580, 2004)

There is growing evidence that essential hypertension is commonly neurogenic and is initiated and sustained by sympathetic nervous system overactivity. Potential mechanisms include increased central sympathetic outflow, altered norepinephrine (NE) neuronal reuptake, diminished arterial baroreflex dampening of sympathetic nerve traffic, and sympathetic neuromodulation by angiotensin II. To address this issue, we used microneurography and radiotracer dilution methodology to measure regional sympathetic activity in 22 hypertensive patients and 11 normotensive control subjects. The NE transport inhibitor desipramine was infused to directly assess the potential role of impaired neuronal NE reuptake. To evaluate possible angiotensin sympathetic neuromodulation, the relation of arterial and coronary sinus plasma concentrations of angiotensin II to sympathetic activity was investigated. Hypertensive patients displayed increased muscle sympathetic nerve activity and elevated total systemic, cardiac, and renal NE spillover. Cardiac neuronal NE reuptake was decreased in hypertensive subjects. In response to desipramine, both the reduction of fractional transcardiac 3 [H]NE extraction and the increase in cardiac NE spillover were less pronounced in hypertensive patients. DNA sequencing analysis of the NE transporter gene revealed no mutations that could account for reduced transporter activity. Arterial baroreflex control of sympathetic nerve traffic was not diminished in hypertensive subjects. Angiotensin II plasma concentrations were similar in both groups and were not related to indexes of sympathetic activation. Increased rates of sympathetic nerve firing and reduced neuronal NE reuptake both contribute to sympathetic activation in hypertension, whereas a role for dampened arterial baroreflex restraint on sympathetic nerve traffic and a peripheral neuromodulating influence of angiotensin II appear to be excluded.

The renin-angiotensin system (RAS) and the kallikrein-kinin system (KKS) each encompasses a large number of molecules, with several participating in both systems. The RAS generates a family of bioactive angiotensin peptides with varying biological activities. These include angiotensin-(1-8) (Ang II), angiotensin-(2-8) (Ang III), angiotensin-(3-8) (Ang IV), and angiotensin-(1-7) [Ang-(1-7)]. Ang II and Ang III act on type 1 (AT(1)) and type 2 (AT(2)) angiotensin receptors, whereas, Ang IV and Ang-(1-7) act on their own receptors. The KKS also generates a family of bioactive peptides with varying biological activities. These include hydroxylated and non-hydroxylated bradykinin and kallidin peptides and their carboxypeptidase metabolites des-Arg(9)-bradykinin and des-Arg(10)-kallidin. Whereas bradykinin and kallidin act mainly via the type 2 bradykinin (B(2)) receptor, des-Arg(9)-bradykinin and des-Arg(10)-kallidin act mainly via the type 1 bradykinin (B(1)) receptor. The AT(1) receptor forms heterodimers with the AT(2) and B(2) receptors and there is cross talk between the AT(1) and epidermal growth factor receptors. The B(2) receptor also interacts with angiotensin converting enzyme and nitric oxide synthase. Both angiotensin and kinin peptides are metabolised by many different peptidases that are important determinants of the activities of the RAS and KKS, and several of which participate in both systems.

To investigate the pathophysiology underlying raised lactate levels after cardiac surgery with cardiopulmonary bypass (CPB).Prospective observational study.Medical and surgical intensive care unit of a tertiary hospital.A total of 40 patients undergoing first-time coronary artery bypass grafting with CPB.The prothrombotic response to cardiac surgery with CPB was assessed by measuring plasma levels of prothrombin fragment 1 + 2 and plasminogen activator inhibitor (PAI) activity. The hemodynamic responses to cardiac surgery with CPB were also measured using standard techniques.After cardiac surgery, prothrombin fragment 1 + 2 levels increased 6-fold and PAI activity increase 2- to 3-fold (p.0001). Lactate levels were not associated with prothrombin fragment 1 + 2 and PAI activity levels after CPB. Lactate levels were associated with baseline PAI activity (p =.006), a history of hypertension (p =.02), raised baseline lactate levels (p =.02), an early increase in body temperature after CPB (p =.05), a late increase in oxygen consumption after CPB (p =.03), and a raised white cell count after CPB (p =.06). Lactate levels were inversely associated with the maximum activated clotting time level reached during CPB (p =.02). Multivariate linear regression demonstrated lactate levels were independently associated with baseline PAI activity.We found cardiac surgery with CPB was associated with a marked prothrombotic response. Lactate levels were associated with elevated baseline PAI activity and evidence of an amplified inflammatory response to cardiac surgery with CPB. Our findings implicate aspects of the inflammatory response, including microvascular thrombosis, in the development of raised lactate levels after cardiac surgery with CPB.

The enormous benefits of inhibition of ACE demonstrate that manipulation of the metabolism of peptide hormones is a valuable therapeutic strategy for cardiovascular disease. Recent attempts to expand these benefits have combined ACE inhibition with inhibition of other peptidases such as neutral endopeptidase (NEP) in a single molecule, a strategy known as vasopeptidase inhibition. NEP metabolizes natriuretic peptides, and NEP inhibition offers the prospect of combining the benefits of increased natriuretic peptide levels with those of ACE inhibition. However, peptidases such as ACE and NEP have many different substrates, and there are complex interactions between ACE inhibition and NEP inhibition. Both ACE and NEP metabolize the kinin peptides bradykinin and kallidin, and NEP also converts angiotensin (Ang) I to Ang-(1-7) and metabolizes Ang II and endothelin. Addition of NEP inhibition to ACE inhibition potentiates the ACE inhibitor–induced increase in kinin levels, increases Ang II levels, reduces Ang-(1-7) levels, and may increase endothelin levels. These additional consequences of combined ACE/NEP inhibition increase the risk of angioedema and may counteract any benefit of ACE inhibition that depends on reduced Ang II levels and increased Ang-(1-7) levels. Further considerations are that the ratio of ACE and NEP inhibition is fixed for vasopeptidase inhibitors, and there is uncertainty how these drugs should be compared with ACE inhibitors. Vasopeptidase inhibitors will therefore require careful evaluation before they are introduced to patient care.

We used cardiopulmonary bypass (CPB) as a model of activation of the contact system and investigated the involvement of the plasma and tissue kallikrein-kinin systems (KKS) in this process. Circulating levels of bradykinin and kallidin and their metabolites, plasma and tissue kallikrein, low and high molecular weight kininogen, and kallistatin were measured before, during, and 1, 4, and 10 h after CPB in subjects undergoing cardiac surgery. Bradykinin peptide levels increased 10- to 20-fold during the first 10 min, returned toward basal levels by 70 min of CPB, and remained 1.2- to 2.5-fold elevated after CPB. Kallidin peptide levels showed little change during CPB, but they were elevated 1.7- to 5.2-fold after CPB. There were reductions of 80 and 60% in plasma and tissue kallikrein levels, respectively, during the first minute of CPB. Kininogen and kallistatin levels were unchanged. Angiotensin-converting enzyme inhibition did not amplify the increase in bradykinin levels during CPB. Aprotinin administration prevented activation of the KKS. The changes in circulating kinin and kallikrein levels indicate activation of both the plasma and tissue KKS during activation of the contact system by CPB.

The aim of this study is to compare the efficacy of an angiotensin-converting enzyme inhibitor with a dihydropyridine calcium channel blocker in preventing progression to macroalbuminuria and/or a decline in renal function in normotensive patients with type 1 diabetes and microalbuminuria. Forty-two patients were randomized to treatment with either perindopril, slow-release nifedipine, or placebo. In the first 3 months, drug dosage was titrated to achieve a decrease in diastolic blood pressure of at least 5 mm HG: Thirty-three patients had a minimum of 24 months' data, and 25 patients were followed up beyond 36 months (mean, 67 +/- 4 months). Patients were studied every 3 months and at the end of the treatment period; those who remained normotensive discontinued therapy and were followed up for an additional 3 months. Baseline geometric mean albumin excretion rates (AERs) were as follows: perindopril, 66 microg/min; nifedipine, 59 microg/min; and placebo, 66 microg/min. During the first 3 years, 7 of the perindopril-treated but none of the placebo or nifedipine-treated patients reverted to normoalbuminuria (P < 0.01). Median AERs at 3 years of treatment in each group were 23 microg/min for perindopril, 122 microg/min for nifedipine, and 112 microg/min for placebo patients (P < 0.01). In patients with more than 3 years' follow-up, median AERs decreased by 45% in the first year and then stabilized in the perindopril group, but increased by 17.6% in the nifedipine group and 27.6% in the placebo group (P < 0.03) in the first year, then increased progressively. In these same patients, there was a significant decline in glomerular filtration rate in the nifedipine group (-7.8 +/- 1.8 mL/min/1.73 m(2)/y), but not in the other two groups (perindopril, -1.0 +/- 1.2 mL/min/1.73 m(2)/y; placebo, -1.3 +/- 1.1 mL/min/1.73 m(2)/y; P = 0.004). At the end of the study, cessation of treatment for 3 months was associated with a doubling of AERs in the perindopril-treated group, but no change in the other two groups (P < 0.001). In conclusion, long-term perindopril therapy is more effective than nifedipine or placebo in delaying the progression of diabetic nephropathy and reducing AER to the normoalbuminuric range (

The kinin peptide system in humans is complex. Whereas plasma kallikrein generates bradykinin peptides, glandular kallikrein generates kallidin peptides. Moreover, a proportion of kinin peptides is hydroxylated on proline3 of the bradykinin sequence. We established HPLC-based radioimmunoassays for nonhydroxylated and hydroxylated bradykinin and kallidin peptides and their metabolites in blood and urine. Both nonhydroxylated and hydroxylated bradykinin and kallidin peptides were identified in human blood and urine, although the levels in blood were often below the assay detection limit. Whereas kallidin peptides were more abundant than bradykinin peptides in urine, bradykinin peptides were more abundant in blood. Bradykinin and kallidin peptide levels were higher in venous than arterial blood. Angiotensin-converting enzyme inhibition increased blood levels of bradykinin, but not kallidin, peptides. Reactive hyperemia had no effect on antecubital venous levels of bradykinin or kallidin peptide levels. These studies demonstrate differential regulation of the bradykinin and kallidin peptide systems, and indicate that blood levels of bradykinin peptides are more responsive to angiotensin-converting enzyme inhibition than blood levels of kallidin peptides.

Abstract —Angiotensin-converting enzyme (ACE) converts angiotensin I (Ang I) to angiotensin II (Ang II) and metabolizes bradykinin and kallidin peptides. Decreased Ang II levels and increased kinin peptide levels are implicated in the mediation of the therapeutic effects of ACE inhibition. However, alternative non-ACE pathways of Ang II formation have been proposed to predominate in human heart. We investigated the effects of ACE inhibition on cardiac tissue levels of angiotensin and kinin peptides. High-performance liquid chromatography–based radioimmunoassays were used to measure angiotensin peptides and hydroxylated and nonhydroxylated bradykinin and kallidin peptides in right atrial appendages of subjects who had been prepared for cardiopulmonary bypass. Peptide levels in subjects who received ACE inhibitor therapy were compared with those who did not receive ACE inhibitor therapy. ACE inhibition reduced Ang II levels, which was associated with an 80% reduction in the Ang II/Ang I ratio. ACE inhibition did not modify either bradykinin or kallidin peptide levels or the bradykinin-(1-7)/bradykinin-(1-9) ratio. The 80% reduction in the Ang II/Ang I ratio by ACE inhibition indicated a primary role for ACE in the conversion of Ang I to Ang II in atrial tissue. These data support a role for reduced Ang II levels but do not support a role for increased kinin peptide levels in mediating the direct cardiac effects of ACE inhibition.

The benefit of blood pressure-lowering therapy in individuals with normal blood pressure who are at high cardiovascular risk creates a challenge in how best to advocate such therapy. Arguments based on a putative causal role for blood pressure and the need to reduce blood pressure may be less likely to succeed than arguments based on the need to prevent and to reverse the cardiovascular disease that causes cardiovascular events.

ObjectivesBleeding into the chest is a major cause of blood transfusion and adverse outcomes following cardiac surgery. The authors investigated predictors of bleeding following cardiac surgery to identify potentially correctable factors.DesignData were retrieved from the medical records of patients undergoing cardiac surgery over the period of 2002 to 2008. Multivariate analysis was used to identify the independent predictors of chest tube drainage.SettingTertiary hospital.ParticipantsTwo thousand five hundred seventy-five patients.InterventionsCardiac surgery.ResultsThe individual operating surgeon was independently associated with the extent of chest tube drainage. Other independent factors included internal mammary artery grafting, cardiopulmonary bypass time, urgency of surgery, tricuspid valve surgery, redo surgery, left ventricular impairment, male gender, lower body mass index and higher preoperative hemoglobin levels. Both a history of diabetes and administration of aprotinin were associated with reduced levels of chest tube drainage.ConclusionsThe individual operating surgeon was an independent predictor of the extent of chest tube drainage. Attention to surgeon-specific factors offers the possibility of reduced bleeding, fewer transfusions, and improved patient outcomes.

BACKGROUND: Obesity is associated with diastolic dysfunction, lower maximal myocardial blood flow, impaired myocardial metabolism and increased risk of heart failure. We examined the association between obesity, left ventricular filling pressure and myocardial structure. METHODS: We performed histological analysis of non-ischemic myocardium from 57 patients (46 men and 11 women) undergoing coronary artery bypass graft surgery who did not have previous cardiac surgery, myocardial infarction, heart failure, atrial fibrillation or loop diuretic therapy. RESULTS: Non-obese (body mass index, BMI, ≤ 30 kg/m(2), n=33) and obese patients (BMI >30 kg/m(2), n=24) did not differ with respect to myocardial total, interstitial or perivascular fibrosis, arteriolar dimensions, or cardiomyocyte width. Obese patients had lower capillary length density (1145 ± 239, mean ± SD, vs. 1371 ± 333 mm/mm(3), P=0.007) and higher diffusion radius (16.9 ± 1.5 vs. 15.6 ± 2.0 μm, P=0.012), in comparison with non-obese patients. However, the diffusion radius/cardiomyocyte width ratio of obese patients (0.73 ± 0.11 μm/μm) was not significantly different from that of non-obese patients (0.71 ± 0.11 μm/μm), suggesting that differences in cardiomyocyte width explained in part the differences in capillary length density and diffusion radius between non-obese and obese patients. Increased BMI was associated with increased pulmonary capillary wedge pressure (PCWP, P

1. Angiotensin converting enzyme (ACE) converts angiotensin I to angiotensin II, and also metabolizes bradykinin-(1-9) to bradykinin-(1-7) and bradykinin-(1-7) to bradykinin-(1-5). Increases in endogenous kinin levels may contribute to the therapeutic effects of ACE inhibitors. 2. ACE inhibitors increase vascular levels of both bradykinin-(1-9) and its ACE cleavage product bradykinin-(1-7), at doses below the threshold for ACE inhibition, leading to the proposal that ACE inhibitors may also inhibit a non-ACE kininase which cleaves both kinin peptides; this non-ACE kininase may be the major pathway of kinin metabolism in the vasculature and some other tissues. 3. In support of this proposal, ACE inhibitors potentiate bradykinin-(1-9) effects at doses which have little or no effect on ACE activity, as indicated by angiotensin I conversion to angiotensin II. ACE inhibitors also potentiate the actions of ACE-resistant kinin analogues, which may be susceptible to metabolism by a non-ACE kininase. 4. Identification and characterization of the putative non-ACE kininase which is inhibited by ACE inhibitors may reveal novel approaches to the tissue-specific modulation of kinin levels.

Background: Heart failure is associated with abnormalities of myocardial structure, and plasma levels of the advanced glycation end-product (AGE) N-epsilon-(carboxymethyl) lysine (CML) correlate with the severity and prognosis of heart failure. Aging is associated with diastolic dysfunction and increased risk of heart failure, and we investigated the hypothesis that diastolic dysfunction of aging humans is associated with altered myocardial structure and plasma AGE levels. Methods: We performed histological analysis of non-ischemic left ventricular myocardial biopsies and measured plasma levels of the AGEs CML and low molecular weight fluorophores (LMWFs) in 26 men undergoing coronary artery bypass graft surgery who had transthoracic echocardiography before surgery. None had previous cardiac surgery, myocardial infarction, atrial fibrillation, or heart failure. Results: The patients were aged 43-78 years and increasing age was associated with echocardiographic indices of diastolic dysfunction, with higher mitral Doppler flow velocity A wave (r = 0.50, P = 0.02), lower mitral E/A wave ratio (r = 0.64, P = 0.001), longer mitral valve deceleration time (r = 0.42, P = 0.03) and lower early diastolic peak velocity of the mitral septal annulus, e' (r = 0.55, P = 0.008). However, neither mitral E/A ratio nor mitral septal e' was correlated with myocardial total, interstitial or perivascular fibrosis (picrosirius red), immunostaining for collagens I and III, CML, and receptor for AGEs (RAGE), cardiomyocyte width, capillary length density, diffusion radius or arteriolar dimensions. Plasma AGE levels were not associated with age. However, plasma CML levels were associated with E/A ratio (r = 0.44, P = 0.04) and e' (r = 0.51, P = 0.02) and LMWF levels were associated with E/A ratio (r = 0.49, P = 0.02). Moreover, the mitral E/A ratio remained correlated with plasma LMWF levels in all patients (P = 0.04) and the mitral septal e' remained correlated with plasma CML levels in nondiabetic patients (P = 0.007) when age was a covariate. Conclusions: Diastolic dysfunction of aging was independent of myocardial structure but was associated with plasma AGE levels.

Increasing evidence for a latent, preclinical phase of cardiac pathology prior to the development of symptomatic heart failure has fuelled interest in the potential of developing a screening program for early disease detection and intervention. Cardiac biomarkers have shown promise in identifying subjects with significant left ventricular dysfunction and more recently to assist in cardiovascular risk stratification. However, a number of questions remain regarding the use of these biomarkers for screening purposes. In particular, appropriate cut-off levels and adjustment for individual patient characteristics still need to be established and further cost-effectiveness studies are required before screening programs can be undertaken. Given the enormous and increasing burden of cardiac failure worldwide, the potential of these biomarkers to identify those at greatest risk of the condition, either alone or as part of a hybrid screening strategy is of great interest to the cardiology community. The aim of this review is to outline evidence behind the argument for screening, discuss the remaining barriers to its development and implementation and highlight potential areas for future research.