Long-term outcome in diabetic heart failure patients treated with cardiac resynchronization therapy

Effect of short-term cardiac function changes after cardiac resynchronization therapy on long-term prognosis in heart failure patients with and without diabetes

Background

The relationship between short-term cardiac function changes and long-term outcomes in heart failure (HF) patients undergoing cardiac resynchronization therapy (CRT) remains uncertain, especially when stratified by diabetes status.

Objectives

This study aims to assess the association between short-term cardiac function changes and outcomes such as all-cause mortality and HF hospitalization in patients undergoing CRT, stratified by diabetes status.

Design

This is a cohort longitudinal retrospective study.

Methods

A total of 666 HF patients, treated with CRT between March 2007 and March 2019, were included in this study. Among them, 166 patients (24.9%) were diagnosed with diabetes. Cardiac function was assessed at baseline and again at 6 months, incorporating evaluations of left ventricular ejection fraction (LVEF), left ventricular end-diastolic diameter (LVEDD), left atrial diameter (LAD), N-terminal prohormone of brain natriuretic peptide (NT-proBNP), and QRS duration. The QRS duration represents the time required for a stimulus to spread through the ventricles (ventricular depolarization). The primary endpoints of the study were all-cause mortality and HF-related hospitalization.

Results

During a median follow-up of 2.51 years, 172 (25.8%) patients died and 197 (29.6%) were hospitalized for HF. Changes in LVEF, LVEDD, and LAD within 6 months had similar effects on adverse outcomes in both diabetic and nondiabetic patients. However, the presence of diabetes significantly modified the association between changes in NT-proBNP and QRS duration and adverse outcomes. Short-term changes in NT-proBNP and QRS duration were positively associated with all-cause mortality and HF hospitalization in patients without diabetes. However, the relationship between short-term changes in NT-proBNP and QRS duration and adverse outcomes was non-linear in diabetic patients.

Conclusion

Improvement of cardiac function after CRT implantation can reduce long-term risk of all-cause mortality and HF hospitalization in HF patients. However, the presence of diabetes may affect the association between short-term changes in NT-proBNP and QRS duration and adverse outcomes.

Differential effect of cardiac resynchronization therapy in patients with diabetes mellitus: a long-term retrospective cohort study

AIMS

Cardiac resynchronization therapy (CRT) has become an important therapy in patients with heart failure with reduced left ventricular ejection fraction (LVEF). The effect of diabetes on long-term outcome in these patients is controversial. We assessed the effect of diabetes on long-term outcome in CRT patients and investigated the role of diabetes in ischaemic and non-ischaemic cardiomyopathy.

METHODS AND RESULTS

All patients undergoing CRT implantation at our institution between November 2000 and January 2015 were enrolled. The study endpoints were (i) a composite of ventricular assist device (VAD) implantation, heart transplantation, or all-cause mortality; and (ii) reverse remodelling (improvement of LVEF ≥ 10% or reduction of left ventricular end-systolic volume ≥ 15%). Median follow-up of the 418 patients (age 64.6 ± 11.6 years, 22.5% female, 25.1% diabetes) was 4.8 years [inter-quartile range: 2.8;7.4]. Diabetic patients had an increased risk to reach the composite endpoint [adjusted hazard ratio (aHR) 1.48 [95% CI 1.12-2.16], P = 0.041]. Other factors associated with an increased risk to reach the composite endpoint were a lower body mass index or baseline LVEF (aHR 0.95 [0.91; 0.98] and 0.97 [0.95; 0.99], P < 0.01 each), and a higher New York Heart Association functional class or creatinine level (aHR 2.14 [1.38; 3.30] and 1.04 [1.01; 1.05], P < 0.05 each). Early response to CRT, defined as LVEF improvement ≥ 10%, was associated with a lower risk to reach the composite endpoint (aHR 0.60 [0.40; 0.89], P = 0.011). Reverse remodelling did not differ between diabetic and non-diabetic patients with respect to LVEF improvement ≥ 10% (aHR 0.60 [0.32; 1.14], P = 0.118). However, diabetes was associated with decreased reverse remodelling with respect to a reduction of left ventricular end-systolic volume ≥ 15% (aHR 0.45 [0.21; 0.97], P = 0.043). In patients with ischaemic cardiomyopathy, survival rates were not significantly different between diabetic and non-diabetic patients (HR 1.28 [0.83-1.97], P = 0.101), whereas in patients with non-ischaemic cardiomyopathy, diabetic patients had a higher risk of reaching the composite endpoint (HR 1.65 [1.06-2.58], P = 0.027). The latter effect was dependent on other risk factors (aHR 1.47 [0.83-2.61], P = 0.451). The risk of insulin-dependent patients was not significantly higher than in patients under oral antidiabetic drugs (HR 1.55 [95% CI 0.92-2.61], P = 0.102).

CONCLUSIONS

Long-term follow-up revealed diabetes mellitus as independent risk factor for all-cause mortality, heart transplantation, or VAD in heart failure patients undergoing CRT. The detrimental effect of diabetes appeared to weigh heavier in patients with non-ischaemic compared with ischaemic cardiomyopathy.

The role of diabetes in cardiomyopathies of different etiologies-Characteristics and 1-year follow-up results of the EVITA-HF registry

BACKGROUND

Type 2 diabetes is a major risk factor for cardiovascular diseases, e.g. coronary artery disease (CAD). But it has also been shown that diabetes can cause heart failure independently of ischemic heart disease (IHD) by causing diabetic cardiomyopathy. In contrast to diabetes and IHD, limited data exist regarding patients with diabetes and dilated cardiomyopathy (DCM).

METHODS

EVIdence based TreAtment in Heart Failure (EVITA-HF) comprises web-based case report data on demography, diagnostic measures, adverse events and 1-year follow-up of patients hospitalized for chronic heart failure and an ejection fraction ≤40%. In the present study we focused on the results of patients with diabetes and heart failure.

RESULTS

Between February 2009 and November 2015, 4101 patients with chronic heart failure were included in 16 tertiary care centers in Germany. The mortality in patients with diabetes and DCM (n = 323) was more than double (15.2%) than that of DCM patients without diabetes (6.5%, p<0.001, n = 885). In contrast the mortality rate of patients with IHD was not influenced by the presence of diabetes (17.6% in patients with IHD and diabetes n = 945, vs. 14.7% in patients with IHD and no diabetes, n = 1236, p = 0.061). The results also remained stable after performing a multivariable analysis (unadjusted p-value for interaction = 0.002, adjusted p = 0.046).

CONCLUSION

The influence of diabetes on the mortality rate is only significant in patients with DCM not in patients with CAD. Therefore, the underlying mechanisms of this effect should be studied in greater detail to improve patient care and outcome.

Effect of Diabetes Mellitus on Cardiac Resynchronization Therapy and to Prognosis in Heart Failure (from the Prospective Evaluation of Asian With Cardiac Resynchronization Therapy for Heart Failure Study)

The association of diabetes mellitus (DM) with cardiac resynchronization therapy (CRT) response and cardiovascular outcomes in Asian patients with heart failure (HF) is unclear. This study aims to investigate the effects of DM on CRT response and cardiovascular outcomes in Asian HF patients. Consecutive Asian HF patients receiving CRT were enrolled in the Prospective Evaluation of Asian with CRT for Heart Failure (PEACH) study from 2011 to 2017. CRT response and super-response were defined as decrease in end-systolic volume index ≥15% and ≥30%, respectively. Primary endpoint was time to composite of HF-hospitalization and all-cause mortality. Among 161 patients followed for 3.3 ± 1.5 years (age 66.7 ± 11.2 years, 22% females, mean QRS duration 154.3 ± 22.4 ms, 83% left bundle branch block), 84 (52%) were CRT responders and 57 (35%) were super-responders. Of 82 (51%) patients with DM (100% type 2, mean HbA1c 7.3 ± 1.9%), 35 (43%) were responders. DM attenuated reverse remodeling (CRT response: AOR 0.44, 95% confidence interval [CI] 0.20 to 0.98, p < 0.05; super-response: AOR 0.42, 95% CI 0.18 to 0.97, p <0.05), and DM increased HF-hospitalization and all-cause mortality (AHR 1.68, 95% CI 1.00 to 2.82, p = 0.05). The extent of CRT-response correlates with higher event-free survival (CRT response: AHR 0.5, 95% CI 0.30 to 0.81, p = 0.005; super-response: AHR 0.27, 95% CI 0.14 to 0.52, p < 0.001). In conclusion, the extent of reverse remodeling post-CRT is the strongest predictor of event free survival. However, DM is detrimental to the CRT recipient by attenuating reverse remodeling, inducing end organ dysfunction and is independently associated with worsened clinical outcomes among Asian HF patients.

Left ventricular reverse remodelling predicts long-term outcomes in patients with functional mitral regurgitation undergoing MitraClip therapy: results from a multicentre registry

AIMS

To explore whether left ventricular reverse remodelling (LVRR) is a predictor of outcomes in patients with functional mitral regurgitation (FMR) undergoing MitraClip procedure.

METHODS AND RESULTS

We analysed 184 consecutive patients with FMR who underwent successful MitraClip procedure. LVRR was defined as a reduction in left ventricular end-systolic volume ≥ 10% from baseline to 6 months. LVRR was observed in 79 (42.9%) patients. Compared with non-LVRR, LVRR patients were more likely to be females, less likely to have an ischaemic aetiology of mitral regurgitation or a prior (<6 months) heart failure (HF) hospitalization, and had smaller left ventricular dimensions. New York Heart Association class improved from baseline up to 1-year follow-up in both groups. Higher rates of overall survival (87.3% vs. 75.2%, P = 0.039), freedom from HF hospitalization (77.2% vs. 60%, P = 0.020), and freedom from the composite endpoint (cardiovascular mortality or HF hospitalization) (74.7% vs. 55.2%; P = 0.012) were observed in LVRR vs. non-LVRR patients at 2-year follow-up. LVRR was associated with a significant reduction of the adjusted relative risk of mortality, HF hospitalization and composite endpoint [hazard ratio (HR) 0.44; 95% confidence interval (CI) 0.20-0.96, P = 0.040; HR 0.55; 95% CI 0.32-0.97, P = 0.038; and HR 0.54; 95% CI 0.32-0.92, P = 0.023, respectively]. Female gender, absence of diabetes, freedom from prior HF hospitalization, non-ischaemic aetiology of mitral regurgitation, and left ventricular end-diastolic diameter < 75 mm were found to be independent predictors of LVRR.

CONCLUSIONS

Left ventricular reverse remodelling is associated with better long-term outcomes in patients with FMR successfully treated with MitraClip. A careful patient selection may be useful as specific baseline features predict favourable left ventricular remodelling. [Correction added on 17 January 2019, after online publication: the preceding sentence has been changed.].

Type 2 diabetes is independently associated with all-cause mortality secondary to ventricular tachyarrhythmias

OBJECTIVES

The study sought to assess the prognostic impact of type 2 diabetes in patients presenting with ventricular tachyarrhythmias on admission.

BACKGROUND

Data regarding the prognostic outcome of diabetics presenting with ventricular tachyarrhythmias is limited.

METHODS

A large retrospective registry was used including all consecutive patients presenting with ventricular tachycardia (VT) and fibrillation (VF) on admission from 2002 to 2016. Patients with type 2 diabetes (diabetics) were compared to non-diabetics applying multivariable Cox regression models and propensity-score matching for evaluation of the primary prognostic endpoint of long-term all-cause mortality at 2 years. Secondary prognostic endpoints were cardiac death at 24 h, in-hospital death at index, all-cause mortality at 30 days, all-cause mortality in patients surviving index hospitalization at 2 years (i.e. "after discharge") and rehospitalization due to recurrent ventricular tachyarrhythmias at 2 years.

RESULTS

In 2411 unmatched high-risk patients with ventricular tachyarrhythmias, diabetes was present in 25% compared to non-diabetics (75%). Rates of VT (57% vs. 56%) and VF (43% vs. 44%) were comparable in both groups. Multivariable Cox regression models revealed diabetics associated with the primary endpoint of long-term all-cause mortality at 2 years (HR = 1.513; p = 0.001), which was still proven after propensity score matching (46% vs. 33%, log rank p = 0.001; HR = 1.525; p = 0.001). The rates of secondary endpoints were higher for in-hospital death at index, all-cause mortality at 30 days, as well as after discharge, but not for cardiac death at 24 h or rehospitalization due to recurrent ventricular tachyarrhythmias.

CONCLUSION

Presence of type 2 diabetes is independently associated with an increase of all-cause mortality in patients presenting with ventricular tachyarrhythmias on admission.

Comparison of Long-Term Survival Benefits With Cardiac Resynchronization Therapy in Patients With Mild Heart Failure With Versus Without Diabetes Mellitus (from the Multicenter Automatic Defibrillator Implantation Trial With Cardiac Resynchronization Therapy [MADIT-CRT])

We have previously shown a reduction in HF events with cardiac resynchronization therapy with defibrillator (CRT-D) in patients with mild heart failure (HF) and diabetes mellitus (DM). It remains unknown whether HF remission in DM patients with CRT-D translates into reduced mortality. The effects of CRT-D versus an implantable cardioverter-defibrillator (ICD) alone to reduce long-term mortality were assessed in patients with left bundle branch block with DM (n = 386) and without DM (n = 982), enrolled in the Multicenter Automatic Defibrillator Implantation Trial With Cardiac Resynchronization Therapy (MADIT-CRT). We further subdivided DM patients by insulin and noninsulin therapy. Kaplan-Meier survival analyses and multivariate cox proportional hazards regression models were utilized. At the 7-year follow-up, CRT-D was associated with a lower mortality in DM patients compared with ICD alone (21% vs 42%, p = 0.02), similar to non-DM patients (16 vs 24%, p = 0.014). CRT-D was associated with a 41% reduction in the risk of long-term all-cause mortality in DM patients (hazard ratio [HR] 0.59, 95% confidence interval 0.36 to 0.96, p = 0.033) and a similar reduction in non-DM patients (HR 0.69, 95% confidence interval 0.48 to 0.99, p = 0.045, treatment-diabetes interaction p = 0.611). Among DM patients, mortality benefit was evident in insulin-treated patients only (HR 0.40, p = 0.030). Reductions in HF events were present in all groups. In the MADIT-CRT, patients with mild HF with DM derive significant long-term survival benefit from CRT-D, similar to those without DM. The mortality benefit from CRT-D within the DM subgroup seems to be confined to patients with insulin treated diabetes.

Cardiac Resynchronization Therapy in Older Adults with Heart Failure

Heart failure is a disease of poor prognosis marked by frequent hospitalizations, premature death, and impaired quality of life. Despite advances in medical therapy for patients with heart failure and reduced ejection fraction, mortality and hospitalizations with advanced disease are still increased and the quality of life continues to be poor in this population. The advent of cardiac resynchronization therapy has led to a significant improvement in both survival and symptom management in patients with heart failure and reduced ejection fraction. Its beneficial effects in the elderly population, however, are not well-defined.

Sex-specific mortality differences in heart failure patients with ischemia receiving cardiac resynchronization therapy

Background

Recent studies have reported prognosis differences between male and female heart failure patients following cardiac resynchronization therapy (CRT). However, the potential clinical factors that underpin these differences remain to be elucidated.

Methods

A meta-analysis was performed to investigate the factors that characterize sex-specific differences following CRT. This analysis involved searching the Medline (Pubmed source) and Embase databases in the period from January 1980 to September 2016.

Results

Fifty-eight studies involving 33445 patients (23.08% of whom were women) were analyzed as part of this study. Only patients receiving CRT with follow-up greater than six months were included in our analysis. Compared with males, females exhibited a reduction of 33% (hazard ratio, 0.67; 95% confidence interval, 0.62–0.73; P < 0.0001) and 42% (hazard ratio, 0.58; 95% confidence interval, 0.46–0.74; P = 0.003) in all-cause mortality and heart failure hospitalization or heart failure, respectively. Following a stratified analysis of all-cause mortality, we observed that ischemic causes (p = 0.03) were likely to account for most of the sex-specific differences in relation to CRT.

Conclusion

These data suggest that women have a reduced risk of all-cause mortality and heart failure hospitalization or heart failure following CRT. Based on the results from the stratified analysis, we observed more optimal outcomes for females with ischemic heart disease. Thus, ischemia are likely to play a role in sex-related differences associated with CRT in heart failure patients. Further studies are required to determine other indications and the potential mechanisms that might be associated with sex-specific CRT outcomes.

Multipolar pacing by cardiac resynchronization therapy with a defibrillators treatment in type 2 diabetes mellitus failing heart patients: impact on responders rate, and clinical outcomes

BACKGROUND

Type 2 diabetes mellitus (T2DM) is a multi factorial disease, affecting clinical outcomes in failing heart patients treated by cardiac resynchronization therapy with a defibrillator (CRT-d).

METHODS

One hundred and ninety-five T2DM patients received a CRT-d treatment. Randomly the study population received a CRT-d via multipolar left ventricle (LV) lead pacing (n 99, multipolar group), vs a CRT-d via bipolar LV pacing (n 96, bipolar group). These patients were followed by clinical, and instrumental assessment, and telemetric device control at follow up. In this study we evaluated, in a population of failing heart T2DM patients, cardiac deaths, all cause deaths, arrhythmic events, CRT-d responders rate, hospitalizations for HF worsening, phrenic nerve stimulation (PNS), and LV catheter dislodgment events (and re-intervention for LV catheter re-positioning), comparing multipolar CRT-d vs bipolar CRT-d group of patients at follow up.

RESULTS

At follow up there was a statistical significant difference about atrial arrhythmic events [7 (7%) vs 16 (16.7%), p value 0.019], hospitalizations for HF worsening [15 (15.2% vs 24 (25%), p value 0.046], LV catheter dislodgments [1 (1%) vs 9 (9.4%), p value 0018], PNS [5 (5%) vs 18 (18.7%), p value 0.007], and LV re-positioning [1 (1%) vs 9 (9.4%), p value 0.018], comparing multipolar CRT-d vs bipolar CRT-d group of patients. Multipolar pacing was an independent predictor of all these events.

CONCLUSIONS

CRT-d pacing via multipolar LV lead vs bipolar LV lead may reduce arrhythmic burden, hospitalization rate, PNS, LV catheters dislodgments, and re-interventions in T2DM failing heart patients. Clinical trial number NCT03095196.

Cardiac electrophysiological alterations and clinical response in cardiac resynchronization therapy with a defibrillator treated patients affected by metabolic syndrome

Metabolic syndrome (MS) is a multifactorial disease that can affect clinical outcomes in patients treated by Cardiac Resynchronization Therapy with a defibrillator (CRT-d).Ninety-one patients received a CRT-d. According to clinical diagnosis, the study population was divided into 46 MS (cases) versus 45 no MS (controls) patients. These patients were followed by clinical, instrumental assessment, and device telemetric interrogations at follow-up. The design of the study was to evaluate the functionality of the CRT-d leads, the arrhythmic events, the CRT-d response, and the clinical outcomes at follow-up.At follow-up, there was a statistical significant difference, comparing MS versus no MS patients regarding the sensing, pacing, and impedance thresholds of the right atrium, right ventricle, and left ventricle leads. There was a statistically significant difference in the percentage of CRT-d responders comparing MS (n = 16, 51%) versus no MS (n = 40, 77%) patients (P = 0.017). MS may be predictive for hospitalization for heart failure worsening (hazard ratio 0.327, 95% confidence interval 0.096-0.943, P = 0.044) in CRT-d patients.MS is a complex multifactorial disease that may affect the functionality of CRT-d leads, the CRT-d response, and clinical outcomes in failing heart patients. These parameters may be detectable by follow-up monitoring.

[Sudden cardiac death in diabetes mellitus]

Sudden cardiac death (SCD) represents one of the most frequent causes of death in patients with diabetes. In contrast to patients without diabetes it has not been significantly reduced despite improvements in the treatment of acute myocardial infarction and long-term treatment of cardiovascular diseases as well as diabetes mellitus. Several mechanisms can be responsible for the high incidence of SCD in diabetics: 1. arrhythmogenic effects mediated via cardiac autonomic neuropathy, repolarization disturbances or sympathetic tone activation (hypoglycemia), 2. myocardial ischemia due to atherosclerosis, endothelial dysfunction, platelet aggregation or thrombophilic effects, 3. myocardial disease due to inflammation, fibrosis, associated hypertension or uremia and 4. potassium imbalance due to diabetic nephropathy or hypoglycemia. This review introduces concepts of mechanisms that are responsible for SCD in patients with diabetes. Treatment of patients with diabetes should primarily consider a systematic assessment of any deterioration of this chronic disease and of complications at an early stage. Cardiovascular drug treatment corresponds to that of non-diabetics. In antidiabetic treatment drugs with a low risk of hypoglycemia should be preferred. Treatment with implantable cardioverter defibrillators (ICD) also combined with cardiac resynchronization therapy () demonstrated a high life-saving potential particularly in patients with diabetes.

Position paper for management of elderly patients with pacemakers and implantable cardiac defibrillators: Groupe de Rythmologie et Stimulation Cardiaque de la Société Française de Cardiologie and Société Française de Gériatrie et Gérontologie

Despite the increasingly high rate of implantation of pacemakers (PMs) and implantable cardioverter defibrillators (ICDs) in elderly patients, data supporting their clinical and cost-effectiveness in this age stratum are ambiguous and contradictory. We reviewed the data regarding the applicability, safety and effectiveness of conventional pacing, ICDs and cardiac resynchronization therapy (CRT) in elderly patients. Although periprocedural risk may be slightly higher in the elderly, the implantation procedure for PMs and ICDs is still relatively safe in this age group. In older patients with sinus node disease, the general consensus is that DDD pacing with the programming of an algorithm to minimize ventricular pacing is preferred. In very old patients presenting with intermittent or suspected atrioventricular block, VVI pacing may be appropriate. In terms of correcting potentially life-threatening arrhythmias, the effectiveness of ICD therapy is similar in older and younger individuals. However, the assumption of persistent ICD benefit in the elderly population is questionable, as any advantageous effect of the device on arrhythmic death may be attenuated by higher total non-arrhythmic mortality. While septuagenarians and octogenarians have higher annual all-cause mortality rates, ICD therapy may remain effective in selected patients at high risk of arrhythmic death and with minimum comorbidities despite advanced age. ICD implantation among the elderly, as a group, may not be cost-effective, but the procedure may reach cost-effectiveness in those expected to live more than 5-7years after implantation. Elderly patients usually experience significant functional improvement after CRT, similar to that observed in middle-aged patients. Management of CRT non-responders remains globally the same, while considering a less aggressive approach in terms of reinterventions (revision of left ventricular [LV] lead placement, addition of a right ventricular or LV lead, LV endocardial pacing configuration). Overall, physiological age, general status and comorbidities rather than chronological age per se should be the decisive factors in making a decision about device implantation selection for survival and well-being benefit in elderly patients.

Diabetes Mellitus and Outcomes of Cardiac Resynchronization With Implantable Cardioverter-Defibrillator Therapy in Older Patients With Heart Failure

Background—

Large-scale data on outcomes with cardiac resynchronization therapy with defibrillator in patients with diabetes mellitus are limited. We compared outcomes after cardiac resynchronization therapy with defibrillator implantation among patients with heart failure who have diabetes mellitus versus those without diabetes mellitus.

Methods and Results—

Survival curves and covariate adjusted hazard ratio (HR) or odds ratio were used to assess the risks for death, readmission, and device-related complications by diabetes mellitus status among 18 428 patients at least 65 years old receiving cardiac resynchronization therapy with defibrillator from the National Cardiovascular Data Registry, implantable cardioverter-defibrillator registry between 2006 and 2009, with up to 3 years of follow-up. Accounting for differences between groups, compared with those without diabetes mellitus (n=11 345), patients with diabetes mellitus (n=7083) had a higher risk of death both at 1 year (HR, 1.16 [95% confidence interval (CI), 1.05–1.29]; P =0.0037) and 3 years (HR, 1.21 [1.14–1.29]; P <0.001) after device implantation and higher risks of all-cause readmission (sub-HR, 1.16 [1.11–1.21] at 1 year; P <0.0001; sub-HR, 1.15 [1.11–1.19] at 3 years; P <0.0001) and heart failure–related readmission (sub-HR, 1.18 [1.09–1.28] at 1 year; P <0.0001; and sub-HR, 1.22 [1.15–1.30] at 3 years; P <0.0001). Device-related complications within 90 days did not differ between those with and without diabetes mellitus (odds ratio: 0.90 [0.77–1.06]; P =0.37). Interactions of age, sex, ischemic cardiomyopathy, renal failure, or QRS duration were not significant.

Conclusions—

In older patients with heart failure receiving cardiac resynchronization therapy with defibrillator, diabetes mellitus was independently associated with greater risks of death and rehospitalization, but similar risks of procedural complications.

Cardiac Resynchronization Therapy Outcomes in Type 2 Diabetic Patients: Role of MicroRNA Changes

Heart failure (HF) and type 2 diabetes mellitus (T2DM) are two growing and related diseases in general population and particularly in elderly people. In selected patients affected by HF and severe dysfunction of left ventricle ejection fraction (LVEF), with left bundle brunch block, the cardiac resynchronization therapy with a defibrillator (CRT) is the treatment of choice to improve symptoms, NYHA class, and quality of life. CRT effects are related to alterations in genes and microRNAs (miRs) expression, which regulate cardiac processes involved in cardiac apoptosis, cardiac fibrosis, cardiac hypertrophy and angiogenesis, and membrane channel ionic currents. Different studies have shown a different prognosis in T2DM patients and T2DM elderly patients treated by CRT-D. We reviewed the literature data on CRT-D effect on adult and elderly patients with T2DM as compared with nondiabetic patients.

Impaired Diastolic Recovery after Acute Myocardial Infarction as a Predictor of Adverse Events

BACKGROUND

To investigate the impact of left ventricular (LV) diastolic functional recovery on major adverse cardiac events (MACE) 6 months after acute myocardial infarction (AMI) in patients with preserved LV systolic function.

METHODS

A total 463 patients with preserved LV systolic function at 6 months after an AMI were divided into two groups based on the extent of diastolic recovery assessed by echocardiography: group I (n = 241) showed improving diastolic function and group II (n = 222) did not. MACE included death, recurrent myocardial infarction, and rehospitalization due to heart failure, and these events were compared with the patients' characteristics at baseline.

RESULTS

Compared with group I, the patients in group II were older and had a higher prevalence of hypertension and diabetes. Blood levels of hemoglobin and triglyceride were lower in group II, whereas the levels of N-terminal pro-B-type natriuretic peptide (NT-proBNP) and of high-sensitivity C-reactive protein were higher in this group than in group I. MACE were significantly more frequent in group II than in group I. Age, elevated NT-proBNP, and impaired diastolic recovery were significant independent predictors of MACE.

CONCLUSION

Despite improvement in LV systolic function, LV diastolic function had not improved in 222 patients (47.9%) by the 6-month follow-up after the index AMI, and impaired diastolic functional recovery was found to be an independent predictor of MACE. Evaluation of diastolic function would be a useful way to stratify risk in patients discharged after an index AMI.

Effect of Cardiac Resynchronization Therapy in Patients With Insulin-Treated Diabetes Mellitus

Diabetes mellitus (DM) modify outcome in patients with heart failure (HF). We aimed to analyze the risk for death, HF alone, combined end point HF/death, and ventricular tachycardia/ventricular fibrillation (VT/VF) in patients with mild HF without DM and in those with DM, further stratified by the presence of insulin treatment. We determined whether cardiac resynchronization therapy with defibrillator (CRT-D) versus implantable cardioverter defibrillator improves clinical outcomes in these 3 subgroups. Cox proportional hazards regression models were used to analyze 1,278 patients with left bundle branch block in the Multicenter Automatic Defibrillator Implantation Trial With Cardiac Resynchronization Therapy trial. Treatment with CRT-D versus implantable cardioverter defibrillator was associated with 76% risk reduction in all-cause mortality (hazard ratio 0.24; 95% confidence interval 0.08 to 0.74, p = 0.012) in subgroup of diabetic patients treated with insulin only (interaction p = 0.043). Significant risk reduction in HF alone, HF/death, and the VT/VF after CRT-D was observed across investigated groups and similar left ventricular reverse remodeling to CRT-D. In conclusion, patients with mild HF with DM treated with insulin derive significant risk reduction in mortality, in HF, and VT/VF after implantation of CRT-D. Diabetic patients not receiving insulin benefit from CRT-D by reduction of HF events.

Co-Morbidities and Cardiac Resynchronization Therapy: When Should They Modify Patient Selection?

Cardiac resynchronization therapy (CRT) improves symptoms, reduces heart failure related hospitalizations and death in selected patients with heart failure. Based on thousands of patients enrolled in major clinical landmark trials, current guidelines describe in relatively precise terms which cardiac patients should receive a device. However, clinical trials often excluded sicker patients leaving clinicians with the dilemma of how to treat real-life patients with major co-morbidities, frailty, and increasing age, who are otherwise candidates for CRT implantation. This review investigates results from clinical trials and available observational data on the influence of co-morbidities on CRT benefit in order to provide better insight of when and why co-morbidities should modify patient selection for CRT.

Influence of diabetes on cardiac resynchronization therapy in heart failure patients: a meta-analysis

Background

Diabetes mellitus is an independent risk factor of increased morbidity and mortality in patients with heart failure. Cardiac resynchronization therapy (CRT), a pacemaker-based therapy for dyssynchronous heart failure, improves cardiac performance and quality of life, but its effect on mortality in patients with diabetes is uncertain.

Methods

We performed a meta-analysis of results from randomized controlled trials (RCTs) of the long-term outcome of cardiac resynchronization therapy for heart failure in diabetic and non-diabetic patients. Literature search of MEDLINE via Pubmed for reports of randomized controlled trials of Cardiac resynchronization for chronic symptomatic left-ventricular dysfunction in patients with and without diabetes mellitus, with death as the outcome. Relevant data were analyzed by use of a random-effects model. Reports published from 1994 to 2011 that described RCTs of CRT for treating chronic symptomatic left ventricular dysfunction in patients with and without diabetes, with all-cause mortality as an outcome.

Results

A total of 5 randomized controlled trials met the inclusion criteria, for 2,923 patients. The quality of studies was good to moderate. Cardiac resynchronization significantly reduced the mortality for heart failure patients with or without diabetes mellitus. Mortality was 24.3% for diabetic patients with heart failure and 20.4 % for non-diabetics (odds ratio 1.28, 95% confidence interval 1.06–1.55; P = 0.010).

Conclusions

Cardiac resynchronization therapy (CRT) may reduce mortality from progressive heart failure in patients with or without diabetes mellitus, but mortality may be higher for patients with than without diabetes after CRT for heart failure.

More Favorable Response to Cardiac Resynchronization Therapy in Women Than in Men

Background—

Data on sex difference in response to cardiac resynchronization therapy (CRT) remain controversial. We conducted a meta-analysis to summarize all published studies to determine whether sex-based differences in response to CRT exist.

Methods and Results—

We performed a literature search using MEDLINE (source PubMed; January 1966 to March 2014) and EMBASE (January 1980 to March 2014) with no restrictions. Pooled effect estimates were obtained by using random-effects meta-analysis. Seventy-two studies involving 33 434 patients were identified. Overall, female patients had better outcomes from CRT compared with male patients, with a significant 33% reduction in the risk of death from any cause (hazard ratio, 0.67; 95% confidence interval, 0.61–0.74; P <0.001), 20% reduction in death or hospitalization for heart failure (hazard ratio, 0.80; 95% confidence interval, 0.71–0.90; P <0.001), 41% reduction in cardiac death (hazard ratio, 0.59; 95% confidence interval, 0.42–0.84; P <0.001), and 41% reduction in ventricular arrhythmias or sudden cardiac death (hazard ratio, 0.59; 95% confidence interval, 0.49–0.70; P <0.001). These more favorable responses to CRT in women were consistently associated with greater echocardiographic evidence of reverse cardiac remodeling in women than in men.

Conclusions—

Women obtained greater reductions in the risk of death from any cause, cardiac cause, death or hospitalization for heart failure, and ventricular arrhythmias or sudden cardiac death with CRT therapy compared with men, with consistently greater echocardiographic evidence of reverse cardiac remodeling in women than in men. Further studies are needed to investigate the exact reasons for these results and determine whether indications for CRT in women should be different from men.

Neurohormonal Regulation and Improvement in Blood Glucose Control: Reduction of Insulin Requirement in Patients with a Nonpulsatile Ventricular Assist Device

<p><b>Background:</b> Heart failure is associated with prolonged stress and inflammation characterized by elevated levels of cortisol and circulating catecholamines. Persistent sympathetic stimulation secondary to the stress of heart failure causes an induced insulin resistance, which creates a need for higher doses of insulin to adequately manage hyperglycemia in this patient population. We hypothesized that cortisol and catecholamine levels would be elevated in end-stage heart failure patients, however, would be reduced after the implantation of a left ventricular assist device (LVAD). Insulin requirements would therefore be reduced post LVAD implant and control of diabetes improved as compared with pre-implant.</p><p><b>Methods:</b> Pre- and postoperative cortisol, catecholamine, glycated hemoglobin, and blood glucose levels were evaluated retrospectively in 99 LVAD patients at a single center from January 2007 through November 2011. Serum was collected before LVAD implantation and monthly after implantation for 12 months consecutively. Results were evaluated and compared to insulin requirements, if any, before and after implant. Plasma levels were measured by ELISA.</p><p><b>Results:</b> There were a total of 99 patients (81 men and 18 women). Two patients were implanted twice due to pump dysfunction. Mean age was 59 years, � 10, with a median of 63 years. Of those patients, 64 had ischemic cardiomyopathy and 35 had dilated cardiomyopathy. The total patient years of LVAD support were 92.5 years. All patients received a continuous flow left ventricular assist device. Type II diabetes mellitus was diagnosed in 28 patients. Of those patients, 24 required daily insulin with an average dose of 45 units/day. Average preoperative glycated hemoglobin (HbA1c) levels were 6.8% with fasting blood glucose measurements of 136 mg/dL. Mean cortisol levels were measured at 24.3 ?g/dL before LVAD implantation, with mean plasma catecholamine levels of 1824 ?g/mL. Post operatively, average HbA1c levels were 5.38% with fasting blood glucose measurements of 122 mg/dL. Mean cortisol levels were measured at 10.9 ?g/dL with average plasma catecholamine levels were 815 ?g/mL. There was a significant decrease in both cortisol levels post LVAD implant (<i>P</i> = 0.012) as well as catecholamine levels (<i>P</i> = 0.044). The average insulin requirements post LVAD implant were significantly reduced to 13 units/day (<i>P</i> = 0.001). Six patients no longer required any insulin after implant.</p><p><b>Conclusion:</b> Implantation of nonpulsatile LVADs has become a viable option for the treatment of end-stage heart failure, helping to improve patient quality of life by decreasing clinical symptoms associated with poor end-organ perfusion. Frequently, diabetes is a comorbid condition that exists among heart failure patients and with the reduction of the systemic inflammatory and stress response produced by the support of a nonpulsatile LVAD, many patients may benefit from a reduction in their blood glucose levels, as well as insulin requirements.</p>

Impact of diabetes mellitus on the clinical response to cardiac resynchronization therapy in elderly people

Heart failure (HF) and type 2 diabetes mellitus (T2DM) exhibit a well-established interrelationship and a growing prevalence, in particular in elderly people. Cardiac resynchronization therapy (CRT) has been shown to improve myocardial function in patients with HF and cardiac dyssynchrony. However, reports on CRT in diabetic elderly patients are limited and controversial. Therefore, the aim of the present study was to investigate the functional role of T2DM on the effectiveness of CRT at advanced age. In this single-center prospective study, we enrolled 72 HF patients over 75 years old with and without T2DM who underwent CRT implant. Detailed clinical and instrumental data, including cardiac ultrasound analysis, 6-min walk test, and quality-of-life evaluation, were collected at baseline and at 1-year follow-up. At the time of implantation, 44.4 % of patients had T2DM, of which 62.5 % were well controlled with diet and hypoglycemic drugs and 37.5 % were treated by insulin therapy. After 1 year, CRT improved myocardial ventricular geometry and functional capacity in a comparable proportion of diabetic and non-diabetic patients alongside with a similar amelioration in the functional status. Taken together, our findings demonstrate that diabetic patients >75 years old exhibit a response to CRT that is comparable to non-diabetic subjects.

Influence of diabetes on left ventricular systolic and diastolic function and on long-term outcome after cardiac resynchronization therapy

OBJECTIVE

The influence of diabetes on cardiac resynchronization therapy (CRT) remains unclear. The aims of the current study were to 1) assess the changes in left ventricular (LV) systolic and diastolic function and 2) evaluate long-term prognosis in CRT recipients with diabetes.

RESEARCH DESIGN AND METHODS

A total of 710 CRT recipients (171 with diabetes) were included from an ongoing registry. Echocardiographic evaluation, including LV systolic and diastolic function assessment, was performed at baseline and 6-month follow-up. Response to CRT was defined as a reduction of ≥15% in LV end-systolic volume (LVESV) at the 6-month follow-up. During long-term follow-up (median = 38 months), all-cause mortality (primary end point) and cardiac death or heart failure hospitalization (secondary end point) were recorded.

RESULTS

At the 6-month follow-up, significant LV reverse remodeling was observed both in diabetic and non-diabetic patients. However, the response to CRT occurred more frequently in non-diabetic patients than in diabetic patients (57 vs. 45%, P < 0.05). Furthermore, a significant improvement in LV diastolic function was observed both in diabetic and non-diabetic patients, but was more pronounced in non-diabetic patients. The determinants of the response to CRT among diabetic patients were LV dyssynchrony, ischemic cardiomyopathy, and insulin use. Both primary and secondary end points were more frequent in diabetic patients (P < 0.001). Particularly, diabetes was independently associated with all-cause mortality together with ischemic cardiomyopathy, renal function, LVESV, LV dyssynchrony, and LV diastolic dysfunction.

CONCLUSIONS

Heart failure patients with diabetes exhibit significant improvements in LV systolic and diastolic function after CRT, although they are less pronounced than in non-diabetic patients. Diabetes was independently associated with all-cause mortality.

Usefulness of hemoglobin A(1c) to predict outcome after cardiac resynchronization therapy in patients with diabetes mellitus and heart failure

Patients with diabetes and heart failure (HF) have worse clinical outcomes compared to patients with HF without diabetes after cardiac resynchronization therapy (CRT). Patients with HF and diabetes represent a growing population at high risk for cardiovascular events and are increasingly treated with CRT. Although patients with diabetes and HF appear to benefit from CRT, their clinical outcomes are worse than those of patients without diabetes after CRT. The aim of this study was to identify clinical predictors that explain the differential hazard in patients with diabetes. We studied 442 patients (169 with diabetes) with systolic HF referred to the Massachusetts General Hospital CRT clinic from 2003 to 2010 to identify predictors of outcomes after CRT in patients with HF and diabetes. Patients with diabetes were more likely to have ischemic causes of HF than those without diabetes, but there was no difference in the left ventricular ejection fraction or HF classification at implantation. Patients with diabetes had poorer event-free survival (death or HF hospitalization) compared to those without diabetes (log-rank p = 0.04). The presence of diabetes was the most important independent predictor of differential outcomes in the entire population (hazard ratio 1.65, 95% confidence interval 1.10 to 2.51). Patients with diabetes receiving insulin therapy had poorer survival, whereas those not receiving insulin therapy had similar survival to patients without diabetes. Patients with peri-implantation glycosylated hemoglobin >7% had worse outcomes, whereas patients with glycosylated hemoglobin ≤7% had improved survival (hazard ratio 0.36, 95% confidence interval 0.15 to 0.86) equivalent to that of patients without diabetes. In conclusion, although the presence of diabetes, independent of other variables, increases the hazard of worse outcomes after CRT, there is additional risk conferred by insulin use and suboptimal peri-implantation glycemic control.

Cardiac resynchronization therapy in the cardiorenal syndrome

The cardiorenal syndrome (CRS) is a complex clinical syndrome in which dysfunction of either the heart or the kidneys affects the functioning of the other organ system. Many therapies used in heart failure have further detrimental effects on renal function. Cardiac resynchronization therapy (CRT) is a relatively new form of device therapy that reduces morbidity and mortality in patients with heart failure. This review will discuss the effects of CRT on renal function in patients with CRS, the impact of baseline renal function on response to CRT, and potential risks associated with CRT in this unique population.

Cardiac Resynchronization Therapy Reduces the Risk of Cardiac Events in Patients With Diabetes Enrolled in the Multicenter Automatic Defibrillator Implantation Trial With Cardiac Resynchronization Therapy (MADIT-CRT)

Background—

Data are limited regarding whether the presence of diabetes mellitus (DM) influences the benefit of cardiac resynchronization with defibrillator therapy (CRT-D) in heart failure (HF) patients.

Methods and Results—

The effect of CRT-D was evaluated in 1817 patients who were enrolled in the Multicenter Automatic Defibrillator Implantation Trial with Cardiac Resynchronization Therapy (MADIT-CRT). Patients were minimally symptomatic (New York Heart Association class I or II), with ejection fraction ≤0.30 and QRS ≥130 ms. We used Cox regression to determine hazard ratio (HR) of CRT-D versus implantable cardioverter-defibrillator (ICD) therapy for the risk of HF event or death, whichever came first (MADIT-CRT primary end point), in DM (n=552) and non-DM (n=1265) patients. Compared with the non-DM patients, those with DM had more coronary risk factors. During an average follow-up of 2.4 years, DM patients had significantly more primary end point events than non-DM patients (26.6% versus 18%, P <0.001). CRT-D was associated with a significant reduction in risk of primary end point in both DM (HR=0.56, P <0.001) and non-DM patients (HR=0.67, P =0.003). Compared with non-DM patients, CRT-D:ICD HRs in DM patients were lower in the total population, and in subgroups with ischemic cardiomyopathy (0.63 versus 0.64), nonischemic cardiomyopathy (0.39 versus 0.73), and left bundle-branch block (0.36 versus 0.50). There were no significant differences in ventricular remodeling, arrhythmia events, or device-related complications between DM and non-DM patients.

Conclusions—

Patients with diabetes, left ventricular dysfunction, mildly symptomatic HF, and wide QRS complex derive similar benefit from CRT-D compared with patients without diabetes.

Clinical Trial Registration—

URL: http://www.clinicaltrials.gov . Unique identifier: NCT00180271.

Event-free survival following CRT with surgically implanted LV leads versus standard transvenous approach

BACKGROUND

While surgical epicardial lead placement is performed in a subset of cardiac resynchronization therapy patients, data comparing survival following surgical versus transvenous lead placement are limited. We hypothesized that surgical procedures would be associated with increased mortality risk.

METHODS

Long-term event-free survival was assessed for 480 consecutive patients undergoing surgical (48) or percutaneous (432) left ventricle (LV) lead placement at our institution from January 2000 to September 2008.

RESULTS

Baseline clinical and demographic characteristics were similar between groups. While there was no statistically significant difference in overall event-free survival (P = 0.13), when analysis was restricted to surgical patients with isolated surgical lead placement (n = 28), event-free survival was significantly lower in surgical patients (P = 0.015). There appeared to be an early risk (first approximately 3 months postimplantation) with surgical lead placement, primarily in LV lead-only patients. Event rates were significantly higher in LV lead-only surgical patients than in transvenous patients in the first 3 months (P = 0.006). In proportional hazards analysis comparing isolated surgical LV lead placement to transvenous lead placement, adjusted hazard ratios were 1.8 ([1.1,2.7] P = 0.02) and 1.3 ([1.0,1.7] P = 0.07) for the first 3 months and for the full duration of follow-up, respectively.

CONCLUSIONS

Isolated surgical LV lead placement appears to carry a small but significant upfront mortality cost, with risk extending beyond the immediate postoperative period. Long-term survival is similar, suggesting those surviving beyond this period of early risk derive the same benefit as coronary sinus lead recipients. Further work is needed to identify risk factors associated with early mortality following surgical lead placement.

Cardiac resynchronization therapy in the elderly: a realistic option for an increasing population?

Cardiac resynchronization therapy (CRT) has become a mainstay of heart failure treatment. Since heart failure is a disease primarily affecting older patients it is important to evaluate the performance of CRT in this population. Elderly has been suggested as a subgroup less likely to benefit from CRT. This is an important issue that should be clarified, because most patients with heart failure are old. The present review discusses the available data concerning cardiac resynchronization therapy in the elderly, focusing on efficacy, indication, safety, and impact of co-morbidities.

Improved diabetic control in advanced heart failure patients treated with left ventricular assist devices

AIMS

Left ventricular assist devices (LVADs) are increasingly used as therapeutic options for patients with advanced congestive heart failure (CHF), many of whom suffer from diabetes mellitus (DM). The aim of this study was to evaluate the effect of restoration of normal cardiac output using LVAD support on diabetes control in patients with advanced CHF.

METHODS AND RESULTS

A retrospective chart review of all clinic patients supported with long-term LVADs between July 2008 and July 2009 at Columbia University Medical Center was performed. Patients with DM diagnosed prior to device implantation were included in this analysis. Clinical and laboratory data within 1 month preceding and 6 months following LVAD implantation were collected. Of 43 LVAD patients followed in our clinic during the study period, 15 had a diagnosis of DM. Thirteen of the 15 patients were male, mean age was 63 ± 11 years, and the pre-LVAD left ventricular ejection fraction (LVEF) was 16.5 ± 5.7%. Fasting glucose levels, HbA1c, and daily insulin requirement within 1 month before and an average of 4.0 ± 2.3 months after LVAD placement were 157.7 ± 50.6 vs. 104.1 ± 21.4 mg/dL, 7.7 ± 0.9 vs. 6.0 ± 0.8.%, and 53.3 ± 51.7 vs. 24.2 ± 27.2 IU, respectively (P < 0.05 for all comparisons). Six of the 15 patients were completely free of antidiabetic medications and had blood glucose < 126 mg/dL as well as HbA1c < 6% after LVAD. Body mass index (BMI) was slightly increased after LVAD (28.7 ± 5.3 vs. 30.2 ± 4.1 kg/m², P NS).

CONCLUSION

Restoration of normal cardiac output after LVAD implantation improves diabetic control in patients with advanced CHF. Additional studies are warranted to determine the mechanisms that worsen or possibly induce DM in patients with advanced CHF.

Prevalence and characteristics of patients with clinical improvement but not significant left ventricular reverse remodeling after cardiac resynchronization therapy

BACKGROUND

Although most patients who improve in clinical status after cardiac resynchronization therapy (CRT) also show a significant left ventricular (LV) reverse remodeling, some patients do not show echocardiographic improvement. The aim of the present study was to evaluate the degree of agreement between clinical and echocardiographic response to CRT in a large cohort of heart failure patients, and to evaluate the characteristics of patients with clinical response but without echocardiographic response.

METHODS

In 440 consecutive heart failure patients (mean age 66 ± 11 years, 81% men) treated with CRT, agreement between clinical and echocardiographic responses at 6 months of follow-up were evaluated. The combined clinical response was defined as: ≥1-point New York Heart Association functional class improvement or ≥15% increase in 6-minute walk test. Echocardiographic response was defined by a reduction in LV end-systolic volume (LVESV) ≥15%.

RESULTS

At 6 months of follow-up, clinical response was observed in 84% (n = 370) of the patients. Significant reduction in LVESV was noted in 63% (n = 276). The majority of patients who improved clinically did show LV reverse remodeling (72%, n = 268). Importantly, 28% (n = 102) of patients who improved clinically did not show significant LV reverse remodeling. The patients with clinical response but without echocardiographic response had more often ischemic heart failure as compared to patients with positive clinical and echocardiographic response (69.6% vs 57.5%; P = .021). Moreover, patients with such discordant responses had more narrow QRS complex (148 ± 31 vs 159 ± 31 milliseconds; P = .004), and showed less LV dyssynchrony than patients with concordant positive responses (90 ± 77 vs 171 ± 105 milliseconds; P < .001).

CONCLUSIONS

Although there is a good concordance between echocardiographic and clinical response to CRT, up to 28% of the population experienced clinical response without significant LV reverse remodeling. Subjects with such discrepant responses have more frequently ischemic heart failure and show more narrow QRS complex and less LV dyssynchrony than patients with both clinical and echocardiographic response.

Insulin-treated type 2 diabetes is associated with a decreased survival in heart failure patients after cardiac resynchronization therapy

BACKGROUND

Cardiac resynchronization therapy (CRT) improves cardiac performance and survival in patients with congestive heart failure. Recent observations suggest that diabetes is associated with a worse outcome in these patients. The aim of the study was to investigate the effect of diabetes and insulin treatment on outcome after CRT.

METHODS

Diabetic status and insulin treatment were assessed in 447 patients who underwent CRT (males 80.8%, mean age 65.7 +/- 9.7 years, ejection fraction 29.9 +/- 6.11%). Patients were stratified in three groups according to the presence or absence of diabetes and insulin treatment.

RESULTS

Nondiabetic patients were 366 (79.6%), noninsulin-treated diabetic patients 62 (13.9%), insulin-treated diabetic patients 29 (6.5%). The estimated death rate was 5.15 per 100 patients-year in the nondiabetic group, 8.63 in noninsulin-treated diabetics (HR 1.59, P = 0.240), and 15.84 in insulin-treated diabetics (HR 3.05, P = 0.004). Cardiac mortality accounted for 81% of deaths in nondiabetic patients and for 56% of deaths in diabetic patients. Diabetic patients tended to have a worse recovery of left ventricular ejection fraction over time (P = 0.057) and of the distance at 6-minute walking test (6MWT) (P = 0.018).

CONCLUSIONS

Insulin-treated diabetes is associated with a worse functional recovery and a higher mortality in patients with advanced heart failure after CRT. While cardiac death accounts for the majority of deaths in nondiabetic patients, a relevant proportion of the mortality in diabetic patients seem to result from noncardiac causes.