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Previous meta-analyses of summary data from randomised controlled trials have shown that statin therapy increases the risk of diabetes, but less is known about the size or timing of this effect, or who is at greatest risk. We aimed to address these gaps in knowledge through analysis of individual participant data from large, long-term, randomised, double-blind trials of statin therapy.

IMPORTANCE: Studies have demonstrated an association between single measures of high-sensitivity troponin (hsTn) and future cardiovascular events in patients with chronic coronary syndromes. However, limited data exist regarding the association between changes in serial values of hsTn and subsequent cardiovascular events in this patient population. OBJECTIVE: To evaluate the association between changes in high-sensitivity troponin T (hsTnT) and subsequent cardiovascular events in patients stabilized after acute coronary syndrome (ACS). DESIGN, SETTING, AND PARTICIPANTS: This is a secondary analysis from the Improved Reduction of Outcomes: Vytorin Efficacy International Trial (IMPROVE-IT), a randomized clinical trial of ezetimibe vs placebo on a background of simvastatin in 18 144 patients hospitalized for an ACS across 1147 sites in 39 countries. The current biomarker substudy includes the 6035 participants consenting to the biomarker substudy with available hsTnT at months 1 and 4. Data were collected from October 26, 2005, through July 8, 2010, with the database locked October 21, 2014. Data were analyzed from February 28, 2021, through August 14, 2022. MAIN OUTCOMES AND MEASURES: The outcomes of interest were cardiovascular death, myocardial infarction (MI), stroke, or hospitalization for heart failure (HHF). Associations of absolute and relative changes in hsTnT between month 1 and month 4 as a function of the starting month 1 hsTnT and the composite outcome were examined using landmark analyses. RESULTS: Of 6035 patients in this analysis (median [IQR] age, 64 [57-71]), 1486 (24.6%) were female; 361 (6.0%) were Asian; 121 were (2.0%) Black; 252 (4.2%) were Spanish descent; 4959 were (82.2%) White; and 342 (5.7%) reported another race (consolidated owing to small numbers), declined to respond, or were not asked to report race owing to regulatory prohibitions. Most patients (4114 [68.2%]) had stable hsTnT values (change <3 ng/L), with 1158 (19.2%) and 763 (12.6%) having changes of 3 to less than 7 ng/L and 7 ng/L or more, respectively. After adjustment for clinical risk factors and stratification by the starting month 1 hsTnT level, an absolute increase in hsTnT of 7 ng/L or more was associated with a more than 3-fold greater risk of the composite outcome (adjusted hazard ratio [aHR], 3.33; 95% CI, 1.99-5.57; P < .001), whereas decreases of 7 ng/L or more were associated with similar to lower risk (aHR, 0.51; 95% CI, 0.26-1.03; P = .06) compared with stable values. There was a stepwise association moving from larger absolute decreases (aHR, 0.51; 95% CI, 0.26-1.03) to larger absolute increases (aHR, 3.33; 95% CI, 1.99-5.57) in hsTnT with future risk of the composite outcome (P trend <.001). A similar association was observed when analyzed on the basis of relative percent and continuous change. CONCLUSIONS AND RELEVANCE: Among stable patients post-ACS, changes in hsTnT were associated with a gradient of risk of subsequent cardiovascular events across the range of starting hsTnT values. Serial assessment of hsTnT may refine risk stratification with the potential to guide therapy decisions in this patient population. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT00202878

Statin therapy is effective for the prevention of atherosclerotic cardiovascular disease and is widely prescribed, but there are persisting concerns that statin therapy might frequently cause muscle pain or weakness. We aimed to address these through an individual participant data meta-analysis of all recorded adverse muscle events in large, long-term, randomised, double-blind trials of statin therapy.

IMPORTANCE: Lipid management typically focuses on levels of low-density lipoprotein cholesterol (LDL-C) and, to a lesser extent, triglycerides (TG). However, animal models and genetic studies suggest that the atherogenic particle subpopulations (LDL and very-low-density lipoprotein [VLDL]) are both important and that the number of particles is more predictive of cardiac events than their lipid content. OBJECTIVE: To determine whether common measures of cholesterol concentration, TG concentration, or their ratio are associated with cardiovascular risk beyond the number of apolipoprotein B (apoB)–containing lipoproteins. DESIGN, SETTING, AND PARTICIPANTS: This prospective cohort analysis included individuals from the population-based UK Biobank and from 2 large international clinical trials, FOURIER and IMPROVE-IT. The median (IQR) follow-up was 11.1 (10.4-11.8) years in UK Biobank and 2.5 (2.0-4.7) years in the clinical trials. Two populations were studied in this analysis: 389 529 individuals in the primary prevention group who were not taking lipid-lowering therapy and 40 430 patients with established atherosclerosis who were receiving statin treatment. EXPOSURES: ApoB, non–high-density lipoprotein cholesterol (HDL-C), LDL-C, and TG. MAIN OUTCOME AND MEASURES: The primary study outcome was incident myocardial infarction (MI). RESULTS: Of the 389 529 individuals in the primary prevention group, 224 097 (58%) were female, and the median (IQR) age was 56.0 (49.5-62.5) years. Of the 40 430 patients with established atherosclerosis, 9647 (24%) were female, and the median (IQR) age was 63 (56.2-69.0) years. In the primary prevention cohort, apoB, non–HDL-C, and TG each individually were associated with incident MI. However, when assessed together, only apoB was associated (adjusted hazard ratio [aHR] per 1 SD, 1.27; 95% CI, 1.15-1.40; P < .001). Similarly, only apoB was associated with MI in the secondary prevention cohort. Adjusting for apoB, there was no association between the ratio of TG to LDL-C (a surrogate for the ratio of TG-rich lipoproteins to LDL) and risk of MI, implying that for a given concentration of apoB-containing lipoproteins, the relative proportions of particle subpopulations may no longer be a predictor of risk. CONCLUSIONS AND RELEVANCE: In this cohort study, risk of MI was best captured by the number of apoB-containing lipoproteins, independent from lipid content (cholesterol or TG) or type of lipoprotein (LDL or TG-rich). This suggests that apoB may be the primary driver of atherosclerosis and that lowering the concentration of all apoB-containing lipoproteins should be the focus of therapeutic strategies.

IMPORTANCE: Limited evidence is available regarding the benefit and hazard of higher-intensity treatment to lower lipid levels among patients 75 years or older. As a result, guideline recommendations differ for this age group compared with younger patients. OBJECTIVE: To determine the effect on outcomes and risks of combination ezetimibe and simvastatin compared with simvastatin monotherapy to lower lipid levels among patients 75 years or older with stabilized acute coronary syndrome (ACS). DESIGN, SETTING, PARTICIPANTS: In this prespecified secondary analysis of the global, multicenter, prospective clinical randomized Improved Reduction of Outcomes: Vytorin Efficacy International Trial (IMPROVE-IT), outcomes and risks were compared by age among patients 50 years or older after a hospitalization for ACS. Data were collected from October 26, 2005, through July 8, 2010, with the database locked October 21, 2014. Data were analyzed May 29, 2015, through March 13, 2018, using Kaplan-Meier curves and Cox proportional hazards models. INTERVENTIONS: Double-blind randomized assignment to combined simvastatin and ezetimibe or simvastatin and placebo with follow-up for a median of 6 years (interquartile range, 4.3-7.1 years). MAIN OUTCOMES AND MEASURES: The primary composite end point consisted of death due to cardiovascular disease, myocardial infarction (MI), stroke, unstable angina requiring hospitalization, and coronary revascularization after 30 days. Individual adverse ischemic and safety end points and lipid variables were also analyzed. RESULTS: Of 18 144 patients enrolled (13 728 men [75.7%]; mean [SD] age, 64.1 [9.8] years), 5173 (28.5%) were 65 to 74 years old, and 2798 (15.4%) were 75 years or older at randomization. Treatment with simvastatin-ezetimibe resulted in lower rates of the primary end point than simvastatin-placebo, including 0.9% for patients younger than 65 years (HR, 0.97; 95% CI, 0.90-1.05) and 0.8% for patients 65 to 74 years of age (hazard ratio [HR], 0.96; 95% CI, 0.87-1.06), with the greatest absolute risk reduction of 8.7% for patients 75 years or older (HR, 0.80; 95% CI, 0.70-0.90) (P = .02 for interaction). The rate of adverse events did not increase with simvastatin-ezetimibe vs simvastatin-placebo among younger or older patients. CONCLUSIONS AND RELEVANCE: In IMPROVE-IT, patients hospitalized for ACS derived benefit from higher-intensity therapy to lower lipid levels with simvastatin-ezetimibe compared with simvastatin monotherapy, with the greatest absolute risk reduction among patients 75 years or older. Addition of ezetimibe to simvastatin was not associated with any significant increase in safety issues among older patients. These results may have implications for guideline recommendations regarding lowering of lipid levels in the elderly. TRIAL REGISTRATION: ClinicalTrials.gov identifier: NCT00202878

Statin therapy has been shown to reduce major vascular events and vascular mortality in a wide range of individuals, but there is uncertainty about its efficacy and safety among older people. We undertook a meta-analysis of data from all large statin trials to compare the effects of statin therapy at different ages.

Polyvascular disease and type 2 diabetes are each associated with increased cardiovascular risk, but whether these risks are additive is unknown. In this exploratory analysis of a randomised trial, we explored the long-term cardiovascular risk associated with polyvascular disease, type 2 diabetes, and their combination in patients with acute coronary syndrome, and assessed the effect of ezetimibe given on top of statin therapy in patients with these concomitant conditions.

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IMPORTANCE: In the Improved Reduction of Outcomes: Vytorin Efficacy International Trial, intensive low-density lipoprotein cholesterol (LDL-C)–reducing therapy with ezetimibe/simvastatin compared with simvastatin alone was associated with a significant reduction in cardiovascular events in 18 144 patients after acute coronary syndrome. The safety of very low LDL-C levels over the long-term is unknown. OBJECTIVE: To assess the safety and clinical efficacy of achieving a very low (<30 mg/dL) level of LDL-C at 1 month using data from the Improved Reduction of Outcomes: Vytorin Efficacy International Trial. DESIGN, SETTING, AND PARTICIPANTS: This prespecified analysis compared outcomes in patients stratified by achieved LDL-C level at 1 month in the Improved Reduction of Outcomes: Vytorin Efficacy International Trial and adjusted for baseline characteristics during 6 years’ median follow-up. Patients were enrolled from October 26, 2005, to July 8, 2010, and the data analysis was conducted from December 2014 to February 2017. MAIN OUTCOMES AND MEASURES: Safety end points included adverse events leading to drug discontinuation; adverse muscle, hepatobiliary, and neurocognitive events; and hemorrhagic stroke, heart failure, cancer, and noncardiovascular death. Efficacy events were as specified in the overall trial. RESULTS: Among the 15 281 patients included in the study, 11 645 (76.2%) were men and the median age was 63 years (interquartile range, 56.6-70.7 years). In these patients without an event in the first month, the achieved LDL-C values at 1 month were less than 30 mg/dL, 30 to 49 mg/dL, 50 to 69 mg/dL, and 70 mg/dL or greater in 6.4%, 31%, 36%, and 26% of patients, respectively. Patients with LDL-C values less than 30 mg/dL (median, 25 mg/dL; interquartile range, 21-27 mg/dL) at 1 month were more likely randomized to ezetimibe/simvastatin (85%), had lower baseline LDL-C values, and were more likely older, male, nonwhite, diabetic, overweight, statin naive, and presenting with a first myocardial infarction. After multivariate adjustment, there was no significant association between the achieved LDL-C level and any of the 9 prespecified safety events. The adjusted risk of the primary efficacy composite of cardiovascular death, major coronary events, or stroke was significantly lower in patients achieving an LDL-C level less than 30 mg/dL at 1 month (adjusted hazard ratio, 0.79; 95% CI, 0.69-0.91; P = .001) compared with 70 mg/dL or greater. CONCLUSIONS AND RELEVANCE: Patients achieving an LDL-C level less than 30 mg/dL at 1 month had a similar safety profile (and numerically the lowest rate of cardiovascular events) over a 6-year period compared with patients achieving higher LDL-C concentrations. These data provide reassurance regarding the longer-term safety and efficacy of the continuation of intensive lipid-lowering therapy in very higher-risk patients resulting in very low LDL-C levels. TRIAL REGISTRATION: clinicaltrials.gov Identifier: NCT00202878

Introduction:Guideline-directed medical therapy (GDMT) for heart failure with reduced ejection fraction (HFrEF) improves clinical outcomes and quality of life. Optimizing GDMT in the hospital is associated with greater long-term use in HFrEF.Hypothesis:A multidisciplinary virtual HF intervention improves GDMT optimization among patients with HFrEF admitted for any cause.Methods:In this pilot randomized, controlled study, consecutive patients with HFrEF admitted to non-cardiology medicine services for any cause were identified at Duke Hospital between May to September 2021. Major exclusions were end-stage renal disease, hemodynamic instability, and hospice care. Patients were randomized to a clinician-level virtual peer-to-peer consult intervention providing GDMT recommendations and information on medication costs vs. usual care. Primary endpoints included 1) proportion of patients with new GDMT initiation or use, and 2) changes to HF optimal medical therapy (OMT) scores which included target dosing (range 0-9).Results:Of 242 patients identified, 91 (38%) were eligible and randomized to intervention (N=52) or usual care (N=39). Baseline characteristics were similar between intervention and usual care (mean age 63 vs. 67 years, 23% vs. 26% female, 46% vs. 49% Black, mean EF 33% vs. 31%). GDMT use on admission was also similar. There were greater proportions of patients with GDMT initiation or continuation with the intervention compared with usual care (Figure 1). After adjusting for OMT score on admission, changes to OMT score at discharge were higher for the intervention group compared with usual care (+0.44 vs. -0.31, absolute difference +0.75, adjusted estimate 0.86 ± 0.42; p=0.041).Conclusions:Among eligible patients with HFrEF hospitalized for any cause on non-cardiology services, a multidisciplinary pilot virtual HF consultation increased new GDMT initiation and dose optimization at discharge.

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To examine the contributions of chest pain, anxiety, and pain catastrophizing to disability in 97 patients with noncardiac chest pain (NCCP) and to test whether chest pain and anxiety were related indirectly to greater disability via pain catastrophizing.

A 56-year-old man presenting with a 6-month history of recurrent episodic hypotension and bradycardia was found to have limited-stage small cell lung cancer. During both quiescence and episodes of hemodynamic embarrassment, extensive evaluations were conducted. Possible explanations included the following: intermittent great vessel obstruction; baroreceptor failure/hypersensitivity; and autonomic dysfunction. His clinical course favored an antibody-negative dysautonomic paraneoplastic syndrome.

Background:The point prevalence of depression and its relationship to poor outcomes among patients with chronic kidney disease (CKD) has not been fully characterized. Methods:We performed a secondary analysis of a prospective cohort of 374 patients admitted with congestive heart failure between March 1, 1997 and June 30, 1998, to investigate the point prevalence of depression among patients with CKD and its association with mortality. The Beck Depression Inventory (BDI) was administered to all patients. Those who scored 10 or higher were administered the National Institute of Mental Health Diagnostic Interview Schedule (DIS). Logistic regression was used to examine the association between severe CKD, corresponding to a creatinine clearance less than 30 mL/min/72 kg (<0.50 mL/s/72 kg), depression, and mortality at 1 year. Results:Point prevalences of depressive symptoms by BDI and major depression by DIS were 54.8% and 21.6% if severe CKD was present and 32.8% and 13.0% if severe CKD was absent, respectively. After controlling for important clinical factors, severe CKD was associated with depressive symptoms by BDI (odds ratio, 2.89; 95% confidence interval, 1.39 to 5.99). Both depression by DIS and severe CKD were significant predictors of mortality. The increased mortality risk associated with depression did not decline with decreasing kidney function. Conclusion:Depression was more prevalent among patients with than without severe CKD and had at least as strong an association with mortality as compared with depression in patients with no or less severe CKD. The point prevalence of depression decreased when the DIS interview was used, perhaps related to the presence of somatic measures on the BDI reflecting uremia. Studies assessing the efficacy of antidepressants among patients with CKD are needed to determine whether, in addition to treating depression, pharmacotherapy impacts mortality.

Our group has demonstrated that tangential radiation therapy (RT) to the left breast or chest wall can cause perfusion changes in the anterior myocardium. We assess if RT-induced perfusion changes are associated with the development of symptoms consistent with cardiac dysfunction. Between 1998 and 2001, 114 patients were enrolled into an institutional review board—approved prospective study and had pre-RT and serial post-RT (range, 6-24 months) single photon emission computed tomography (SPECT) scans to assess changes in regional cardiac perfusion. Thirty-one patients were excluded. The incidence of cardiac symptoms in patients with and without RT-induced perfusion defects was compared using a 2-tailed Fisher's exact test. With a median follow-up of 16 months (range, 6-24 months), 10 of 83 evaluable patients had ≥ 1 episode of transient chest pain, occurring 0-14 months after RT (median, 6 months). The rates of chest pain in the patients with and without new perfusion defects were 9 of 31 and 1 of 52, respectively (P= 0.0004). A similar result was found when patients were segregated based on the use of chemotherapy. Two of these 10 cases were diagnosed as pericarditis. No patient had myocardial infarction or congestive heart failure. Cardiac symptoms occur more frequently in patients with perfusion abnormalities by SPECT after RT than in patients with normal SPECT scans, suggesting that such perfusion defects may be clinically significant. One confounding factor is that women who know they have RT-induced perfusion defects may be more likely to report episode of chest pain. Long-term follow-up will be necessary to better assess the clinical significance of RT-induced perfusion defects.

Cardiovascular risk might be reduced by targeted changes in both low density and high density lipoprotein cholesterol (LDL-C and HDL-C). This dual strategy will require a well tolerated, effective regimen, as well as a better understanding of how HDL-C may be targeted.

A 66-year-old male with past history of coronary atherosclerosis by angiography was referred for chronic dyspnea. He is a pastor and had noted dyspnea with prolonged standing or walking that resolved with sitting. Serial orthostatic vitals and natriuretic peptides were normal. Subsequent diagnostics included normal pulmonary function and ventilation-perfusion tests, and echocardiography with normal biventricular function, sizes, and estimated pressures. Given ongoing dyspnea, he underwent supine invasive cardiopulmonary exercise testing (iCPET). Resting invasive pressures and cardiac output were normal. At peak exercise, exertional dyspnea was absent but pressures increased to mean PAP 40 and PCWP 28 with preserved cardiac output and 77% predicted maximal aerobic capacity (pVO2). He was diagnosed with exercise induced heart failure with preserved ejection fraction and started on furosemide and spironolactone. On follow-up, he reported worsened dyspnea on therapy, most notably when upright. Stress cardiac MRI showed no scar. Given the positional nature of his symptoms, an iCPET was repeated in the upright position. His diuretics were stopped. Resting supine measurements were similar to the prior iCPET. Upright resting to peak exercise pressures changed minimally (Figure). His profound dyspnea recurred at peak exertion as MAP dropped unexpectedly with paradoxical bradycardia (Bezold-Jarisch reflex) and 62% pVO2. His diagnosis was reclassified as cardiac preload failure. He was advised to increase fluid and salt intake alongside use of leg stockings which remarkably improved his upright and exercise dyspnea symptoms at follow-up. This case highlights an advantage of upright iCPET over supine diagnostics in the comprehensive evaluation of unexplained dyspnea. Cardiac preload failure is the failure to augment preload with exercise and is a common but under-recognized cause of dyspnea often undiagnosed during supine resting and exercise testing.

Introduction:Ezetimibe (EZE) added to statin further reduces LDL-C and CV events. Prior studies demonstrated large inter-individual variability in LDL-C reduction with statins. Whether similar variability exists with EZE has not been reported in a large study.Methods:We assessed the placebo (PBO)-adjusted LDL-C reduction from randomization to 4 months in IMPROVE-IT, a double-blind RCT of EZE vs placebo (PBO) added to simvastatin (SIMVA) post-ACS. Inter-individual variation in % LDL-C reduction was calculated via rank-ordered subtraction of PBO/SIMVA from EZE/SIMVA. Patients not on study drug or with missing LDL-C values at either timepoint were excluded. Using the overall distribution of PBO-adjusted LDL-C reductions with EZE, we modelled the % of patients anticipated to achieve guideline-recommended LDL-C targets at 4 months with the addition of EZE across a range of baseline LDL-C values.Results:In 14,970 pts, the median baseline LDL-C in both groups was 80 mg/dL (IQR 65-96). The median change from baseline at 4 months was -37% (IQR -20% to -51%) in the EZE/SIMVA arm and -14% (IQR +7% to -31%) with PBO/SIMVA (Panel A). The PBO-adjusted median change in LDL-C at 4 months with EZE/SIM was -23% with low variability (IQR -19 to -27%; Panel A). Based on this distribution, modelling predicts that fewer than half of patients would achieve the U.S. and European targets of <70 and <55 mg/dL when the baseline LDL-C is >91 mg/dL and >72 mg/dL, respectively, with the addition of EZE to statin therapy (Panel B).Conclusions:Addition of EZE to statin therapy results in a consistent median 23% reduction in LDL-C, with 75% of patients achieving at least a 19% reduction. The distribution of LDL-C reduction can be used to estimate how likely a patient will be to achieve guideline LDL-C targets with the addition of EZE to statin therapy.

IMPORTANCE: Randomized clinical trials (RCTs) are critical in advancing patient care, yet conducting such large-scale trials requires tremendous resources and coordination. Clinical site start-up performance metrics can provide insight into opportunities for improved trial efficiency but have not been well described. OBJECTIVE: To measure the start-up time needed to reach prespecified milestones across sites in large cardiovascular RCTs in North America and to evaluate how these metrics vary by time and type of regulatory review process. DESIGN, SETTING, AND PARTICIPANTS: This cohort study evaluated cardiovascular RCTs conducted from July 13, 2004, to February 1, 2017. The RCTs were coordinated by a single academic research organization, the Duke Clinical Research Institute. Nine consecutive trials with completed enrollment and publication of results in their target journal were studied. Data were analyzed from December 4, 2019, to January 11, 2021. EXPOSURES: Year of trial enrollment initiation (2004-2007 vs 2008-2012) and use of a central vs local institutional review board (IRB). MAIN OUTCOMES AND MEASURES: The primary outcome was the median start-up time (from study protocol delivery to first participant enrollment) as compared by trial year and type of IRB used. The median start-up time for the top 10% of sites was also reported. Secondary outcomes included time to site regulatory approval, time to contract execution, and time to site activation. RESULTS: For the 9 RCTs included, the median site start-up time shortened only slightly over time from 267 days (interquartile range [IQR], 185-358 days) for 2004-2007 trials to 237 days (IQR, 162-343 days) for 2008-2012 trials (overall median, 255 days [IQR, 177-350 days]; P?&lt;?.001). For the top 10% of sites, median start-up time was 107 days (IQR, 95-121 days) for 2004-2007 trials vs 104 days (IQR, 84-118 days) for 2008-2012 trials (overall median, 106 days [IQR, 90-120 days]; P?=?.04). The median start-up time was shorter among sites using a central IRB (199 days [IQR, 140-292 days]) than those using a local IRB (287 days [IQR, 205-390 days]; P?&lt;?.001). CONCLUSIONS AND RELEVANCE: This cohort study of North American research sites in large cardiovascular RCTs found a duration of nearly 9 months from the time of study protocol delivery to the first participant enrollment; this metric was only slightly shortened during the study period but was reduced to less than 4 months for top-performing sites. These findings suggest that the use of central IRBs has the potential to improve RCT efficiency.

Currently 14 million individuals in the United States have coronary disease. Within the next 2 decades, this number is expected to increase to 21 million persons. To minimize the excessive risk of recurrent cardiac events in these people, evidence-based, cost-effective prevention strategies must be developed. This review highlights the evidence supporting commonly used means of secondary prevention and is divided into two major sections lifestyle modifications and pharmacologic interventions. Lifestyle changes discussed include smoking cessation, especially newer pharmacologic adjuncts; the efficacy of dietary interventions; and current inroads into the treatment of depression in recurrent events. Pharmacologic innovations include reexamination of a role for warfarin; continued advances in the treatment of hyper-and dyslipidemias, new roles for β-blockade in congestive heart failure, and finally a view of future measures, risk, and targets of risk intervention.

Calmodulin (CaM) binding activates neuronal nitric-oxide synthase (nNOS) catalytic functions and also up-regulates electron transfer into its flavin and heme centers. Here, we utilized seven tight binding CaM-troponin C chimeras, which variably activate nNOS NO synthesis to examine the relationship between CaM domain structure, activation of catalytic functions, and control of internal electron transfer at two points within nNOS. Chimeras that were singly substituted with troponin C domains 4, 3, 2, or 1 were increasingly unable to activate NO synthesis, but all caused some activation of cytochrome creduction compared with CaM-free nNOS. The magnitude by which each chimera activated NO synthesis was approximately proportional to the rate of heme iron reduction supported by each chimera, which varied from 0% to ∼80% compared with native CaM and remained coupled to NO synthesis in all cases. In contrast, chimera activation of cytochrome creduction was not always associated with accelerated reduction of nNOS flavins, and certain chimeras activated cytochrome creduction without triggering heme iron reduction. We conclude: 1) CaM effects on electron transfer at two points within nNOS can be functionally separated. 2) CaM controls NO synthesis by governing heme iron reduction, but enhances reductase activity by two mechanisms, only one of which is associated with an increased rate of flavin reduction.

Objectives: Nitric oxide synthases (NOS) generate nitric oxide (NO), a second messenger with key regulatory roles. In the cardiovascular system, deficient endothelial NO production is an early, persistent feature of atherosclerosis and vascular injury. Accordingly, the NOS isoforms represent attractive targets for vascular gene therapy. We aimed to generate and evaluate an adenoviral vector for gene transfer of an NOS isoform to vascular cells. Methods: We constructed a recombinant adenovirus, Ad.nNOS, for gene transfer of the neuronal isoform of NOS (nNOS) and characterized its expression in 293 cells, human vascular smooth muscle cells (hVSMC) and human umbilical vein endothelial cells (HUVEC). NOS expression was analyzed by Western immunoblotting, and NOS enzyme activity in response to receptor-dependent and receptor-independent agonists was determined by Griess assay or by NO chemiluminescence. Results: Ad.nNOS-infected 293 cells expressed high levels of functional nNOS enzyme, even higher than in 293.NOS cells (a cell line that expresses supraphysiologic levels of nNOS). In hVSMC, nNOS activity reached levels 50% of those seen in 293.NOS cells. nNOS expression and activity in hVSMC increased linearly with titer of Ad.nNOS. NO production in hVSMC was stimulated both by calcium ionophore and by physiologic agonists such as acetylcholine or bradykinin. In HUVEC, endogenous NOS activity was significantly augmented by Ad.nNOS infection. Supplementation with the tetrahydrobiopterin precursor sepiapterin enhanced NOS activity in all cells. Conclusions: Ad.nNOS, a novel adenoviral vector for gene transfer of NOS, generates high-level nNOS expression in a variety of vascular cell types. nNOS activity in hVSMC is physiologically regulated and of a magnitude comparable to native eNOS activity in HUVEC. Our findings demonstrate Ad.nNOS to be a versatile and efficient tool for nNOS gene transfer, with widespread potential applications in cell culture and for gene therapy.

Gene transfer technologies offer great potential both to investigate and alter the course of vessel wall pathophysiology. Replication-deficient adenovirus vectors appear particu larly useful for the transfection of blood vessels, because of their ability to accommodate large cDNA inserts and to rapidly and efficiently infect mammalian endothelial and smooth muscle cells. The potential effects of transfection with a replication-deficient adenovirus on vasomotor function have not, however, been described. This study reports gene transfer experiments with a replication-deficient adenovirus containing a cytome galovirus promotor and a nuclear localizing variant of the bacterial β-galactosidase gene. Excised carotid artery segments from 6 rabbits were divided into four segments and infected in pairs for thirty minutes with four viral titers (control [0], 2.5×109, 5×109, and 1×1010pfu/mL) at 37°C in serum-free culture media (M199). Expression of β-galac tosidase and in vitro vasomotor function were determined after seventy-two hours' incu bation. Isometric tension studies were performed to examine the response of the vessel segments to the contractile agonist norepinephrine. β-galactosidase was expressed in all vessel segments exposed to the adenovirus. There was a significant difference in the sensitivity to norepinephrine (P < 0.04) of the segments treated with the highest and lowest viral titers (mean ±sem, -log10[EC50] of 5.98 ±0.09, 5.77 ±0.11, 5.68 ±0.14, and 5.52 ±0.13 for the control, 2.5×109, 5×109, and 1×1010plaque-forming units (pfu)/mL groups respectively). Replication-deficient adenovirus vectors can rapidly and efficiently infect rabbit carotid vessels, but there is, however, a dose-dependent alteration of in vitro vessel vasomotor function that may be mediated by a cytotoxic effect of the viral vector. Although further in vivo work is required to verify these results, this effect needs to be taken into account in studies involving adenoviral gene transfer.

Despite over 20 years of clinical use and 15 years of clinical trial data, we still do not have a complete understanding of the mechanisms of action or full utility of statins as a class of drugs. The possibility of their use as a treatment for prevention of peri‐operative morbidity and mortality is one of the newest indications being explored for this class of drugs. Issues regarding drug dosing and timing may rely on being able to elucidate and separate potential pleiotropic actions from lipid‐lowering actions to identify the optimal benefit of these drugs in the peri‐operative setting. Careful consideration of these two actions need to be considered in the design of adequately powered clinical trials to test the potential utility and safety of using statins in the peri‐operative setting.

Despite over 20 years of clinical use and 15 years of clinical trial data, we still do not have a complete understanding of the mechanisms of action or full utility of statins as a class of drugs. The possibility of their use as a treatment for prevention of peri-operative morbidity and mortality is one of the newest indications being explored for this class of drugs. Issues regarding drug dosing and timing may rely on being able to elucidate and separate potential pleiotropic actions from lipid-lowering actions to identify the optimal benefit of these drugs in the peri-operative setting. Careful consideration of these two actions need to be considered in the design of adequately powered clinical trials to test the potential utility and safety of using statins in the peri-operative setting.

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Background:Recent evidence suggests that LDL levels alone may be an incomplete assessment of cardiovascular risk, given the emerging importance of LDL density. Specifically, an excess of low-density LDL (Pattern B vs. AB or A) has been shown in primary prevention cohorts to be particularly atherogenic. To date, however, the prevalence of Pattern B profiles among patients presenting with an MI has not been described.