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Background: Increased risk of severe tachyarrhythmias is reported in patients with type 2 diabetes mellitus (T2DM). The aim of this study was to explore if treatment with cardiac implantable electronic device (CIED) such as implantable cardioverter defibrillator (ICD), cardiac resynchronization therapy- pacemaker and -defibrillator (CRT-P/CRT-D) differed in patients with vs. without T2DM. A secondary aim was to identify patient characteristics indicating an increased CIED treatment. Method: 416 162 adult patients with T2DM from the Swedish National Diabetes Registry and 2 081 087 controls from the Swedish population, matched for age, sex and living area, were included between 1/1/1998 and 31/12/2012 and followed until 31/12/2013. They were compared regarding prevalence of ventricular tachycardia (VT) at baseline and the risk of receiving a CIED during follow-up. Multivariable Cox regression analysis was performed to estimate the risk of CIED-treatment and factors identifying patients with such risk. Results: Ventricular fibrillation (VF) (0.1% vs 0.0004%) and (VT) (0.2% vs. 0.1%) were more frequent among patients with T2DM compared to controls. CIED-treatment was significantly increased in patients with T2DM both in unadjusted and adjusted analyses. HR and 95% CI, after adjustment for sex, age, marital status, income, education, country of birth, coronary artery disease and congestive heart failure, were 1.32 [1.21–1.45] for ICD, 1.74 [1.55–1.95] for CRT-P and 1.69 [1.43–1.99] for CRT-D. Blood-pressure and lipid lowering therapies were independent risk factors associated to receiving CIED, while female sex was protective. Conclusions: Although the proportion of VT/VF was low, patients with T2DM had a higher prevalence of these conditions and increased risk for treatment with CIED compared to controls. This underlines the importance of recognizing that T2DM patients have an increased need of CIED. [ABSTRACT FROM AUTHOR]

Objective: Patients with type 2 diabetes have an increased risk for cardiovascular disease, including arrhythmias. The prevalence of bradyarrhythmia and the subsequent need for treatment with pacemakers (PMs) is less well explored in a contemporary patient population. The current study explores 1) whether patients with type 2 diabetes have an increased demand for PM implantation compared with an age- and sex-matched control population without diabetes and 2) patient characteristics associated with an increased demand for receiving a PM.Research Design and Methods: In this population-matched registry study, a total of 416,247 patients with type 2 diabetes from the Swedish National Diabetes Registry and 2,081,235 age- and sex-matched control subjects selected from the general population were included between 1 January 1998 and 31 December 2012 and followed until 31 December 2013. Mean follow-up time was 7 years. Cox proportional hazards regression analyses were performed to estimate the demand of PM treatment and the factors identifying patients with such demand.Results: Type 2 diabetes was associated with an increased need of PM treatment (hazard ratio 1.65 [95% CI 1.60-1.69]; P < 0.0001), which remained (1.56 [1.51-1.60]; P < 0.0001) after adjustments for age, sex, educational level, marital status, country of birth, and coronary heart disease. Risk factors for receiving a PM included increasing age, HbA1c, BMI, diabetes duration, and lipid- and blood pressure-lowering medication.Conclusions: The need for PM treatment is higher in patients with type 2 diabetes than in matched population-based control subjects. Age, diabetes duration, and HbA1c seem to be risk factors for PM treatment. [ABSTRACT FROM AUTHOR]

In the above-referenced article, it was stated in the Research Design and Methods subsection "Statistical Analysis" and in the Results subsection "Demand for PM Treatment" that pacemaker implantations during the time of observation were expressed as number of events per 10,000 person-years; however, the correct number is events per 100,000 person-years. The authors apologize for the error. The online version of the article (https://doi.org/10.2337/dc20-0084) has been updated with the correct data. [ABSTRACT FROM AUTHOR]

Aims Myocardial contractile reserve (MCR) is a marker of myocardial viability. The impact of cardiac resynchronization therapy (CRT) on MCR during exercise has been little studied. Our aim was to investigate the effects of CRT on global and regional MCR by exercise echocardiography. Methods and results Twenty-seven CRT responders (56% ischaemic) were assessed by echocardiography during rest and bicycle exercise. Images were acquired during spontaneous rhythm (‘off') and active CRT (‘on'). Global MCR was expressed as the change (Δ) in left ventricular ejection fraction (LVEF) and aortic velocity-time integral (VTI) from rest to exercise. Regional MCR was expressed as the change in peak systolic tissue velocity (Sm) of the septum and lateral wall. Left ventricular ejection fraction and aortic VTI increased at ‘on' during rest and exercise, and the increase in global MCR during exercise was higher during ‘on' than ‘off' (Δ LVEF 6 ± 6 vs. 3 ± 3%; P= 0.009). Septum Sm increased during ‘on' at rest, and it was still higher during exercise (P≤ 0.01), although the absolute change from rest to exercise was similar during ‘on' and ‘off'. Lateral wall Sm did not change at rest during ‘on', but basal lateral wall MCR during exercise was higher at ‘on' than ‘off' (P= 0.036). Conclusion In CRT responders, there is a pacing-dependent increase in global MCR during exercise. The changes in regional MCR of the septum and lateral wall show different patterns. These factors may help to understand the determinants of improved exercise tolerance in CRT responders. [ABSTRACT FROM PUBLISHER]

Abstract: Background: Relatively limited and conflicting data are available on the effects of cardiac resynchronization therapy (CRT) on coronary blood flow (CBF). Aims: To investigate changes in the left anterior descending coronary artery (LAD) flow under different CRT pacing modes by means of transthoracic Doppler echocardiography (TTE). Methods: Twenty-two responders to CRT (67±11 years) with idiopathic dilated cardiomyopathy underwent TTE assessment of LAD flow and Tissue Velocity Imaging during 4 programming modes: intrinsic conduction (IC), right ventricular pacing (RV), simultaneous biventricular pacing (BVP), BVP with left ventricular (LV) pre-activation. Results: Mean coronary flow velocity (CFV) was increased by simultaneous BVP (p =0.0063 vs. IC) and BVP with LV pre-activation (p <0.0001 vs. IC; p =0.027 vs. simultaneous BVP). Peak CFV and LAD flow velocity/time integral were highest during BVP with LV pre-activation. A reduction in septal-to-lateral delay and an increase in peak systolic velocity in the basal septum were observed during simultaneous BVP and BVP with LV pre-activation. Conclusions: In CRT responders with idiopathic dilated cardiomyopathy, an increase in LAD flow, assessed by TTE, was observed during simultaneous BVP and BVP with LV pre-activation. This was associated with an improvement in regional myocardial contraction and a decrease in intraventricular dyssynchrony. [Copyright &y& Elsevier]

Objectives: We compared the effects of triple-site versus dual-site biventricular stimulation in candidates for cardiac resynchronization therapy. Background: Conventional biventricular stimulation with a single right ventricular (RV) and a single left ventricular (LV) lead is associated with persistence of cardiac dyssynchrony in up to 30% of patients. Methods: This multicenter, single-blind, crossover study enrolled 40 patients (mean age 70 ± 9 years) with moderate-to-severe heart failure despite optimal drug treatment, a mean LV ejection fraction of 26 ± 11%, and permanent atrial fibrillation requiring cardiac pacing for slow ventricular rate. A cardiac resynchronization therapy device connected to 1 RV and 2 LV leads, inserted in 2 separate coronary sinus tributaries, was successfully implanted in 34 patients. After 3 months of biventricular stimulation, the patients were randomly assigned to stimulation for 3 months with either 1 RV and 2 LV leads (3-V) or to conventional stimulation with 1 RV and 1 LV lead (2-V), then crossed over for 3 months to the alternate configuration. The primary study end point was quality of ventricular resynchronization (Z ratio). Secondary end points included reverse LV remodeling, quality of life, distance covered during 6-min hall walk, and procedure-related morbidity and mortality. Data from the 6- and 9-month visits were combined to compare end points associated with 2-V versus 3-V. Results: Data eligible for protocol-defined analyses were available in 26 patients. No significant difference in Z ratio, quality of life, and 6-min hall walk was observed between 2-V and 3-V. However, a significantly higher LV ejection fraction (27 ± 11% vs. 35 ± 11%; p = 0.001) and smaller LV end-systolic volume (157 ± 69 cm3 vs. 134 ± 75 cm3; p = 0.02) and diameter (57 ± 12 mm vs. 54 ± 10 mm; p = 0.02) were observed with 3-V than with 2-V. There was a single minor procedure-related complication. Conclusions: Cardiac resynchronization therapy with 1 RV and 2 LV leads was safe and associated with significantly more LV reverse remodeling than conventional biventricular stimulation. [Copyright &y& Elsevier]

Abstract: Background: Haemodynamic and functional effects of cardiac resynchronization therapy (CRT) have been studied mostly at rest. CRT effects on left ventricular (LV) dyssynchrony and function during stress have not been evaluated in detail. Aims: We studied the electromechanical effects of CRT at rest and during Dobutamine stress echocardiography (DSE), during active and withheld CRT. Methods: Twenty-one responders to CRT (62±12 yr) were assessed by walking test, quality of life, and BNP with active CRT (“on”) and 2 weeks after pacing withdrawal (“off”). DSE (10 μg/kg/min) was performed both at “on” and “off” to evaluate dyssynchrony parameters, systolic and diastolic function. Results: At rest, CRT withdrawal was associated with an increased interventricular mechanical delay (IVMD, from 21±18 ms to 49±24 ms, p <0.001) and impaired intraventricular synchrony. There was a significant decrease in LV systolic function and LV filling time. Dobutamine infusion had no impact on inter- and intraventricular synchrony. During stress, there was an improvement in LV performance both at “on” and “off”. However, LV dp/dt, aortic VTI, cardiac output, mean systolic peak velocities and LV filling time during dobutamine stress were significantly greater with CRT “on”. Conclusion: In long-term responders, CRT improves LV performance both at rest and during dobutamine stress. This is attributable to an improvement in LV synchrony, which is maintained during stress. [Copyright &y& Elsevier]

Gender differences in symptoms and perceived health-related quality of life (HRQOL) in patients with atrial fibrillation (AF) referred to pulmonary vein isolation (PVI) have been reported previously. Women experience a lower HRQOL, faster heart rate, and more symptoms such as palpitation and dyspnea than men. Furthermore, they experience worse physical functioning independently of other heart diseases or age. This study evaluates referral patterns and symptoms, morbidity, functional impairment, and HRQOL from a gender perspective in patients with AF before and 6 months after PVI. The study includes 242 patients (121 men), mean age 62 ± 9 years, referred for PVI. Symptoms were assessed with the Symptom Checklist: Frequency and Severity (SCL), HRQOL with Short Form 36 (SF-36), and the functional impairment with Sickness Impact Profile (SIP). The patients' own experiences of the referral process and history of their disease were evaluated with a supplementary questionnaire. The results showed that women improved more than men in HRQOL, SIP, and SCL 6 months post PVI. There were no sex differences in proportion of paroxysmal and persistent AF or ablation outcome. At baseline, women scored higher than men in both scales of the SCL (p < 0.001), scored lower in all components in SF-36, and scored higher in five categories of the SIP. Women were not more reluctant to accept referral for ablation when offered. The conclusion is that women with AF undergoing PVI are more symptomatic but also improve more in HRQOL and in symptom burden than men. [ABSTRACT FROM AUTHOR]

Background: Health-related quality of life (HRQL) in hypertrophic cardiomyopathy (HCM) patients with implantable cardioverter-defibrillators (ICDs) is largely unknown. The aim was to assess HRQL, including comparisons between groups, using the questionnaire SF-36, and compare it to a Swedish age- and sex-matched population.Methods and Results: Validated data on adult HCM patients with ICDs were used. The SF-36 response rate was 82.5 % and 245 patients (mean age 55.9 years, 70.2 % men) were analyzed using the Mann-Whitney U-test, t-test, Spearman correlation and effect size calculations. In all SF-36 domains the patients' score was lower (p-value of <0.0001) than norms except for bodily pain. The general health domain showed the highest effect size (0.77) and the impact was more pronounced in the SF-36 physical component summary score (0.62) than the mental component summary score (0.46). Older age was correlated with lower scores on the physical component and higher scores on the mental component. Atrial fibrillation and/or systolic heart failure were associated with worse physical health. HRQL was similar in primary vs secondary prevention cases. Inappropriate ICD shock was associated with worse mental health while appropriate therapy trended toward better mental health.Conclusion: HCM patients with ICDs suffer from poor HRQL regardless of age, sex, or primary vs secondary prevention indication. Atrial fibrillation and systolic heart failure are determinants of poor physical health. Inappropriate shocks, but not appropriate therapies, are associated with poorer mental health. [ABSTRACT FROM AUTHOR]

The health care costs for heart failure are substantial. Studies indicate that hospital treatment constitutes 65–75% of these. The aim of this study was to assess total and heart failure related hospital days as well as safety and efficacy of biventricular pacing in 16 patients with severe heart failure and delayed intraventricular conduction (QRS duration <150 ms). They were implanted with a biventricular pacemaker and followed by NYHA class, 6-min walk test and quality of life for a mean of 291±76 days. Total number of hospital days and the need for hospitalisations were monitored. Thirteen responders improved by at least one functional class. After 6 months of pacing the 6-min walk test improved from 375±83 m to 437±73 m (P<0.001) and Minnesota Living with Heart Failure quality of life score from 41±19 to 24±17 (P<0.001) compared to baseline. The need for hospital care decreased significantly after biventricular pacing. The total number of hospital days in all patients was 253 the year before compared to 45 the year after biventricular pacing (P<0.01). For heart failure related hospital days the corresponding figures were 183 and 39 days, respectively (P<0.01). Biventricular pacing improved 13/16 patients with severe heart failure and wide QRS complexes in this open study. The improvement resulted in a reduced need for hospital care. [ABSTRACT FROM PUBLISHER]

Background: The risk of sudden cardiac death (SCD) is high early after myocardial infarction (MI). Current knowledge and guidelines mainly rely on results from older clinical trials and registry studies. Left ventricular ejection fraction (LVEF) alone has not been proven a reliable predictor of SCD.Objectives: This study sought to identify the incidence and additional predictors of SCD early after MI in a contemporary nationwide setting.Methods: The authors used data from SWEDEHEART, the Swedish Cardiopulmonary Resuscitation Registry, and the Swedish Pacemaker and Implantable Cardioverter-Defibrillator (ICD) Registry. Cases of MI, which had undergone coronary angiography and were discharged alive between 2009 to 2017 without a prior ICD, were followed up to 90 days. Cox regression models were used to assess associations between clinical parameters and out-of-hospital cardiac arrest (OHCA).Results: Among 121,379 cases, OHCA occurred in 349 (0.29%) and non-OHCA death in 2,194 (1.8%). A total of 6 variables (male sex, diabetes, estimated glomerular filtration rate <30 ml/min/1.73 m2, Killip class ≥II, new-onset atrial fibrillation/flutter, and impaired LVEF [reference ≥50%] categorized as 40% to 49%, 30% to 39%, and <30%) were identified as independent predictors, were assigned points, and were grouped into 3 categories, where the incidence of OHCA ranged from 0.12% to 2.0% and non-OHCA death from 0.76% to 11.7%. Stratified by LVEF <40% alone, the incidence of OHCA was 0.20% and 0.76% and for non-OHCA death 1.1% and 4.9%.Conclusions: In this nationwide study, the incidence of OHCA within 90 days after MI was <0.3%. A total of 5 clinical parameters in addition to LVEF predicted OHCA and non-OHCA death better than LVEF alone. [ABSTRACT FROM AUTHOR]

Aims The European CRT Survey is a joint initiative of the Heart Failure Association (HFA) and the European Heart Rhythm Association (EHRA) of the European Society of Cardiology evaluating the contemporary implantation practice of cardiac resynchronization therapy (CRT) in Europe. Methods and results Patients who had a successful CRT implantation were enrolled from 141 centres in 13 countries between November 2008 and June 2009. Baseline demographics, clinical and implantation data were collected, with a follow-up of ∼1 year (9–15 months). The current report describes clinical outcomes including symptom severity, cardiovascular (CV) hospitalization, and survival. A total of 2438 patients were enrolled, and follow-up data were acquired from 2111 patients (87%). The population included important groups of patients poorly represented in randomized controlled trials, including very elderly patients and those with prior device implantation, atrial fibrillation, and/or QRS duration <120 ms. Investigators reported substantial improvement in New York Heart Association (NYHA) functional class at follow-up. Patient self-assessment indicated that 81% of the patients felt improved, 16% reported no change, and 4% reported deterioration. During follow-up, 207 (10%) patients died, 346 (16%) had a CV hospitalization, and 501 (24%) died or had CV hospitalization. Worse NYHA functional class, atrial fibrillation, ischaemic aetiology, and device type (CRT-P, i.e. CRT alone) were associated with poorer survival. Women had a better outcome, as did patients who had a CRT-D (with an implantable cardioverter defibrillator function) device. Conclusions Outcomes including death and hospitalization in this European CRT survey were consistent with results from clinical trials of CRT. At 1 year follow-up, most patients who received a CRT device considered their symptoms improved compared with their pre-implant assessment. Although prospective, this is an observational study of successful CRT implantations, and outcomes in subgroup analyses must be interpreted with appropriate conservatism. [ABSTRACT FROM AUTHOR]

Aims Cardiac resynchronization therapy (CRT) is an effective treatment for a subset of patients with chronic heart failure. Data on the benefit of CRT in heart failure patients with previous right ventricular pacemakers or standard defibrillators are sparse. Methods and results The European (HFA, Heart Failure Association/EHRA, European Heart Rhythm Association) CRT Survey enrolled patients from 141 centres in 13 countries in Europe collecting baseline demographic, echocardiographic, clinical, and implant data, with follow-up at ∼1 year. The present analysis reports implantation data and 1 year outcomes regarding New York Heart Association (NYHA) class, global patient assessment, hospitalizations, complications, and mortality in patients undergoing de novo CRT implantations compared with those receiving an upgrade of a previously implanted device (pacemaker or implantable cardioverter–defibrillators). This analysis includes 2367 CRT implant procedures of which 692 (28%) were upgrades to CRT. Distribution of NYHA functional class and left ventricular function were similar between the groups. Procedural duration was also similar, although fluoroscopy time was shorter in the ‘upgrades’. There was no difference in the frequency of peri-procedural complications. There were similar improvements in NYHA functional class and similar reduction in QRS duration, but more patients reported unchanged global assessment status in the upgraded group. Total and cause-specific mortality at 1 year was low and the same in both groups. Conclusions More than one quarter of all CRT procedures are upgrades from existing systems, although this group has not been subject to randomized clinical trials. Our data suggest that there are no significant differences in clinical outcomes or complication rates between upgrades and de novo procedures. Clinical study no NCT 01185392 [ABSTRACT FROM AUTHOR]

: ObjectivesWe tested the hypothesis that left ventricular (LV) pacing is superior to right ventricular (RV) apical pacing in patients undergoing atrioventricular (AV) junction ablation and pacing for permanent atrial fibrillation.: BackgroundThe potential benefit of LV over RV pacing needs to be evaluated without the confounding effect of other variables that can influence cardiac performance.: MethodsAn acute intrapatient comparison of the QRS width and echocardiographic parameters between RV versus LV pacing was performed within 24 h after ablation in 44 patients. Both modes of pacing were also compared with pre-implantation values.: ResultsCompared with RV pacing, LV pacing caused a 5.7% increase in the ejection fraction (EF) and a 16.7% decrease in the mitral regurgitation (MR) score; the QRS width was 4.8% shorter with LV pacing. Similar results were observed in patients with or without systolic dysfunction and/or native left bundle branch block, except for a greater improvement in MR in the latter group. Compared with pre-ablation measures, the EF increased by 11.2% and 17.6% with RV and LV pacing, respectively; the MR score decreased by 0% and 16.7%; and the diastolic filling time increased by 12.7% and 15.6%.: ConclusionsRhythm regularization achieved with AV junction ablation improved EF with both RV and LV pacing; LV pacing provided an additional modest but favorable hemodynamic effect, as reflected by a further increase of EF and reduction of MR. The effect seems to be equal in patients with both depressed and preserved systolic functions and in those with and without native left bundle branch block. [Copyright &y& Elsevier]