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

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.

Association between triglyceride glucose-body mass index and heart failure in subjects with diabetes mellitus or prediabetes mellitus: a cross-sectional study

Background

The triglyceride glucose-body mass index (TyG-BMI) is a surrogate indicator of insulin resistance. However, the association of TyG-BMI with heart failure (HF) in individuals with diabetes mellitus or prediabetes mellitus is unknown.

Methods

This study included 7,472 participants aged 20-80 years old with prediabetes or diabetes from the National Health and Nutrition Examination Survey (2007-2018). The TyG-BMI was calculated as Ln [triglyceride (mg/dL) × fasting blood glucose (mg/dL)/2] × BMI, and individuals were categorized into tertiles based on TyG-BMI levels. The relationship of TyG-BMI with HF was analyzed using multiple logistic regression models. Subgroup analyses were stratified by gender, age, hypertension, and diabetes mellitus status.

Results

This cross-sectional study had 7,472 participants (weighted n = 111,808,357), including 329 HF participants. Participants with a high TyG-BMI were prone to HF. The highest tertile group with a fully adjusted model was more likely to have HF compared to the lowest tertile group (odds ratio [OR], 2.645; 95% CI, 1.529-4.576). Restricted cubic spline analysis showed a significant dose-response relationship between TyG-BMI and HF (P < 0.001). In subgroup analyses, similar results were seen in terms of age (≥50 years old), gender, hypertension, and diabetes mellitus status.

Conclusion

A high TyG-BMI is significantly associated with HF risk in participants with diabetes mellitus or prediabetes mellitus.

Influence of diabetes on mortality and ICD therapies in ICD recipients: a systematic review and meta-analysis of 162,780 patients

Background

The influence of diabetes on the mortality and risk of implantable cardioverter defibrillator (ICD) therapies is still controversial, and a comprehensive assessment is lacking. We performed this systematic review and meta-analysis to address this controversy.

Methods

We systematically searched the PubMed, Embase, Web of Science and Cochrane Library databases to collect relevant literature. Fixed and random effects models were used to estimate the hazard ratio (HR) with 95% CIs.

Results

Thirty-six articles reporting on 162,780 ICD recipients were included in this analysis. Compared with nondiabetic ICD recipients, diabetic ICD recipients had higher all-cause mortality (HR = 1.45, 95% CI 1.36–1.55). The subgroup analysis showed that secondary prevention patients with diabetes may suffer a higher risk of all-cause mortality (HR = 1.89, 95% CI 1.56–2.28) (for subgroup analysis, P = 0.03). Cardiac mortality was also higher in ICD recipients with diabetes (HR = 1.68, 95% CI 1.35–2.08). However, diabetes had no significant effect on the risks of ICD therapies, including appropriate or inappropriate therapy, appropriate or inappropriate shock and appropriate anti-tachycardia pacing (ATP). Diabetes was associated with a decreased risk of inappropriate ATP (HR = 0.56, 95% CI 0.39–0.79).

Conclusion

Diabetes is associated with an increased risk of mortality in ICD recipients, especially in the secondary prevention patients, but does not significantly influence the risks of ICD therapies, indicating that the increased mortality of ICD recipients with diabetes may not be caused by arrhythmias. The survival benefits of ICD treatment in diabetes patients are limited.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12933-022-01580-y.

Heart Failure: An Underappreciated Complication of Diabetes. A Consensus Report of the American Diabetes Association

Heart failure (HF) has been recognized as a common complication of diabetes, with a prevalence of up to 22% in individuals with diabetes and increasing incidence rates. Data also suggest that HF may develop in individuals with diabetes even in the absence of hypertension, coronary heart disease, or valvular heart disease and, as such, represents a major cardiovascular complication in this vulnerable population; HF may also be the first presentation of cardiovascular disease in many individuals with diabetes. Given that during the past decade, the prevalence of diabetes (particularly type 2 diabetes) has risen by 30% globally (with prevalence expected to increase further), the burden of HF on the health care system will continue to rise. The scope of this American Diabetes Association consensus report with designated representation from the American College of Cardiology is to provide clear guidance to practitioners on the best approaches for screening and diagnosing HF in individuals with diabetes or prediabetes, with the goal to ensure access to optimal, evidence-based management for all and to mitigate the risks of serious complications, leveraging prior policy statements by the American College of Cardiology and American Heart Association.

Real-world experience of angiotensin receptor neprilysin inhibitor on the glucose-lowering effect

We investigated the effect of angiotensin receptor neprilysin inhibitor (ARNI) on glycemic control in Korean patients. This retrospective cohort study was conducted at a single tertiary hospital. We compared the HbA_1c level reduction between the ARNI and angiotensin-converting enzyme inhibitors (ACEIs) or angiotensin II receptor blockers (ARBs) in chronic heart failure patients with diabetes. We also examined whether the target HbA_1c level was reached and the time to start insulin between the two groups. Over the study period, ARNI did not significantly lower the HbA_1c level after adjusting confounding factors compared to ACEIs or ARBs. However, as a result of a simple comparison using Mann–Whitney U test, ARNI group showed significant decrease in HbA_1c at 6, 12, and 24 months compared to ACEIs or ARBs group (p = 0.003, 0.009, and 0.026, respectively). The initiation of insulin was delayed in the ARNI group, but this difference was not significant based on the result of hazard ratio, but cumulative incidence was significantly lower in the ARNI group. In the real world, the blood glucose-control effects of ARNI were not superior to those of ACEIs or ARBs. However, long-term studies are needed as ARNI use increases to obtain more statistically significant results.

What Have We Learned in the Last 20 Years About CRT Non-Responders?

Although cardiac resynchronization therapy (CRT) has become well established in the treatment of heart failure, the management of patients who do not respond after CRT remains a key challenge. This review will summarize what we have learned about non-responders over the last 20 years and discuss methods for optimizing response, including the introduction of novel therapies.

Heart Involvement in Diabetes mellitus Patients

Diabetes mellitus (DM) is one of the most significant medical and social health problems worldwide. The main cause of death in patients with DM is cardiovascular diseases, which leads to the significant decrease in quality of life and life expectancy. The aim of this literature review is analyze of the frequency, mechanisms and manifestations of heart disease in diabetes patients. A significant amount of the modern researches is devoted to the diagnosis and treatment of the diabetes complications, including diabetic cardiomyopathy (DC). According to many authors, heart disease in diabetes is associated with the formation of DC, comorbid coronary heart disease and arterial hypertension. DC occurs in 16.8–54% of patients with diabetes and is an independent factor which increases the death risk by 50–60%. Numerous scientific studies have been devoted to the diagnosis and treatment of DC, emphasizing that in order to reduce cardiovascular disease and mortality in patients with diabetes, it is necessary, above all, to achieve glycemic control. Diabetic history, age, comorbidities, atherosclerotic lesions, smoking, overweight or obesity also play an important role. The main aspects of the development and impact of diabetes on the health and life of patients are the untimely diagnosis of this disease, its multifactorial pathogenesis, progressive course and severity of complications. Due to development of the early complications and disability, studies of morphofunctional changes in the myocardium in diabetes are extremely relevant, as cardiomyopathy may increase the risk of myocardial infarction and heart failure. The rapid increase in the number of patients with diabetes, many of whom die from cardiovascular complications, makes the problem of diabetic heart disease one of the most pressing health problems. Treatment of these patients should include correction of carbohydrate metabolism, control of blood lipid composition, decrease in myocardial ischemia, correction of the myocardial metabolism and the risk of heart failure.

Effect of Diabetes Mellitus on 30 and 90-Day Readmissions of Patients With Heart Failure

The prevalence of diabetes mellitus (DM) in hospitalized heart failure (HF) patients is increasing over time. However, the effect of DM on short-term readmissions for HF is not well established. We investigated the effects of DM on readmissions of HF patients. All adult hospitalizations with a primary diagnosis of HF were identified in the National Readmission Database (NRD) for 2018 and were categorized into those with and without a secondary diagnosis of DM. The primary outcome was to assess risk difference in 30 and 90-day all-cause readmissions. Multivariate Cox survival analysis and multivariate Cox regression were performed to estimate the readmission risk difference in HF patients with and without DM. Of 925,637 HF hospitalizations that met the inclusion criteria, 441,295 (47.6%) had concomitant DM. Diabetics hospitalized for HF had higher prevalence of obesity (37.3% vs 19.5%), kidney disease (58.4% vs 29.2%) and coronary disease (61.1% vs 51.0%), compared to HF hospitalizations without DM. In adjusted analyses, DM was associated with higher hazards for all-cause [hazards ratio (HR), 30 days: 1.04 (1.02-1.06); 90 days: 1.07 (1.05-1.09)], HF [HR, 30 days: 1.05 (1.02-1.07); 90 days: 1.08 (1.05-1.10)] and myocardial infarction (MI) [HR, 30 days: 1.26 (1.12-1.41); 90 days: 1.38 (1.25-1.52)] readmissions. In conclusion, in patients with HF-related hospitalizations, the presence of DM was associated with a higher risk of 30 and 90-day all-cause, HF and MI readmissions.

Safety and Efficacy of Adding Dapagliflozin to Furosemide in Type 2 Diabetic Patients With Decompensated Heart Failure and Reduced Ejection Fraction

Background: Heart failure is the most common cause of hospitalization in elderly patients. It is likely that many of the mechanisms that contribute to reductions in systolic and diastolic function, seen in diabetic patients, place them at an increased risk of heart failure. Diuretic therapy, especially loop diuretics, is the usual way of managing congestion, particularly in volume-overloaded patients. Little is known about the beneficial effect of dapagliflozin when added to loop diuretics in managing patients with decompensated heart failure. Aim: To assess the effect of the addition of dapagliflozin to furosemide in managing decompensated patient with heart failure and reduced left ventricular ejection fraction in terms of weight loss and dyspnea improvement. Patients and Methods: The study included 100 type 2 diabetic patients who were admitted with decompensated heart failure. The study population was randomly divided into two arms. Serum electrolytes and kidney functions were followed up during their hospital stay. Results: With dapagliflozin, there was a statistically significant difference between the two groups regarding the change in body weight and body mass index. The diuresis parameters including urine output, total fluid loss, and fluid balance also showed a statistically significant difference in favor of the use of dapagliflozin, with no significant change in serum potassium or kidney functions. There was significant improvement in patient-reported dyspnea scores with the use of dapagliflozin. Conclusions: Dapagliflozin may provide a new drug option in the treatment of heart failure especially among vulnerable group of diabetics. It had no remarkable effects on serum potassium level and kidney functions. Clinical Trial Registration: www.ClinicalTrials.gov, identifier: NCT04385589.

Diabetes mellitus and risk of new-onset and recurrent heart failure: a systematic review and meta-analysis

Despite mounting evidence of the positive relationship between diabetes mellitus (DM) and heart failure (HF), the entire context of the magnitude of risk for HF in relation to DM remains insufficiently understood. The principal reason is because new‐onset HF (HF occurring in participants without a history of HF) and recurrent HF (HF re‐occurring in patients with a history of HF) are not discriminated. This meta‐analysis aims to comprehensively and separately assess the risk of new‐onset and recurrent HF depending on the presence or absence of DM. We systematically searched cohort studies that examined the relationship between DM and new‐onset or recurrent HF using EMBASE and MEDLINE (from 1 Jan 1950 to 28 Jul 2019). The risk ratio (RR) for HF in individuals with DM compared with those without DM was pooled with a random‐effects model. Seventy‐four and 38 eligible studies presented data on RRs for new‐onset and recurrent HF, respectively. For new‐onset HF, the pooled RR [95% confidence interval (CI)] of 69 studies that examined HF as a whole [i.e. combining HF with preserved ejection fraction (HFpEF) and HF with reduced ejection fraction (HFrEF)] was 2.14 (1.96–2.34). The large between‐study heterogeneity (I² = 99.7%, P < 0.001) was significantly explained by mean age [pooled RR (95% CI) 2.60 (2.38–2.84) for mean age < 60 years vs. pooled RR (95% CI) 1.95 (1.79–2.13) for mean age ≥ 60 years] (P < 0.001). Pooled RRs (95% CI) of seven and eight studies, respectively, that separately examined HFpEF and HFrEF risk were 2.22 (2.02–2.43) for HFpEF and 2.73 (2.71–2.75) for HFrEF. The risk magnitudes between HFpEF and HFrEF were not significantly different in studies that examined both HFpEF and HFrEF risks (P = 0.86). For recurrent HF, pooled RR (95% CI) of the 38 studies was 1.39 (1.33–1.45). The large between‐study heterogeneity (I² = 80.1%, P < 0.001) was significantly explained by the proportion of men [pooled RR (95% CI) 1.53 (1.40–1.68) for < 65% men vs. 1.32 (1.25–1.39) for ≥65% men (P = 0.01)] or the large pooled RR for studies of only participants with HFpEF [pooled RR (95% CI), 1.73 (1.32–2.26) (P = 0.002)]. Results indicate that DM is a significant risk factor for both new‐onset and recurrent HF. It is suggested that the risk magnitude is large for new‐onset HF especially in young populations and for recurrent HF especially in women or individuals with HFpEF. DM is associated with future HFpEF and HFrEF to the same extent.

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.

Basic Mechanisms of Diabetic Heart Disease

Diabetes mellitus predisposes affected individuals to a significant spectrum of cardiovascular complications, one of the most debilitating in terms of prognosis is heart failure. Indeed, the increasing global prevalence of diabetes mellitus and an aging population has given rise to an epidemic of diabetes mellitus-induced heart failure. Despite the significant research attention this phenomenon, termed diabetic cardiomyopathy, has received over several decades, understanding of the full spectrum of potential contributing mechanisms, and their relative contribution to this heart failure phenotype in the specific context of diabetes mellitus, has not yet been fully resolved. Key recent preclinical discoveries that comprise the current state-of-the-art understanding of the basic mechanisms of the complex phenotype, that is, the diabetic heart, form the basis of this review. Abnormalities in each of cardiac metabolism, physiological and pathophysiological signaling, and the mitochondrial compartment, in addition to oxidative stress, inflammation, myocardial cell death pathways, and neurohumoral mechanisms, are addressed. Further, the interactions between each of these contributing mechanisms and how they align to the functional, morphological, and structural impairments that characterize the diabetic heart are considered in light of the clinical context: from the disease burden, its current management in the clinic, and where the knowledge gaps remain. The need for continued interrogation of these mechanisms (both known and those yet to be identified) is essential to not only decipher the how and why of diabetes mellitus-induced heart failure but also to facilitate improved inroads into the clinical management of this pervasive clinical challenge.

Important Considerations for the Treatment of Patients with Diabetes Mellitus and Heart Failure from a Diabetologist's Perspective: Lessons Learned from Cardiovascular Outcome Trials

Heart failure (HF) represents an important cardiovascular complication of type 2 diabetes mellitus (T2DM) associated with substantial morbidity and mortality, and is emphasized in recent cardiovascular outcome trials (CVOTs) as a critical outcome for patients with T2DM. Treatment of T2DM in patients with HF can be challenging, considering that these patients are usually elderly, frail and have extensive comorbidities, most importantly chronic kidney disease. The complexity of medical regimens, the high risk clinical characteristics of patients and the potential of HF therapies to interfere with glucose metabolism, and conversely the emerging potential of some antidiabetic agents to modulate HF outcomes, are only some of the challenges that need to be addressed in the framework of a team-based personalized approach. The presence of established HF or the high risk of developing HF in the future has influenced recent guideline recommendations and can guide therapeutic decision making. Metformin remains first-line treatment for overweight T2DM patients at moderate cardiovascular risk. Although not contraindicated, metformin is no longer considered as first-line therapy for patients with established HF or at risk for HF, since there is robust scientific evidence that treatment with other glucose-lowering agents such as sodium-glucose cotransporter 2 inhibitors (SGLT2i) should be prioritized in this population due to their strong and remarkably consistent beneficial effects on HF outcomes.

Sociodemographic and clinical correlates of diabetes self-efficacy in adults with type 2 diabetes and comorbid heart failure

Heart failure (HF) is a comorbidity that complicates type 2 diabetes mellitus (T2D) management and increases the chance of death. However, little is known concerning factors related to diabetes self-efficacy in comorbid HF. This secondary data analysis was aimed at describing sociodemographic and clinical correlates of diabetes self-efficacy in adults with T2D and comorbid HF. A correlational design was used to analyze cross-sectional baseline data from a randomized study of 180 participants that tested a 6-month integrated self-care intervention targeting adults with concomitant HF and T2D. Participants were enrolled from one of four large urban-tertiary hospitals in Atlanta, GA, during 2010-2013. Data were collected from medical records and self-report. We used stepwise multiple linear regressions to examine variables associated with diabetes self-efficacy. The participants' mean age was 58.1 ± 10.7 years and the majority were male (n = 118; 65.6%) and African American (n = 119; 66.1%). Good self-rated health and presence of implantable cardioverter-defibrillator (ICD) had significant positive relationships with diabetes self-efficacy, while taking both oral antiglycemic medication and insulin, history of depression, cardiac pacemaker, and taking digitalis were negatively related. These variables collectively explained 22.4% of the variation in diabetes self-efficacy. One study implication is that using self-rated health provides a quick, patient-centered assessment to evaluate patient health status. Further studies are warranted to ascertain the pathways linking ICD, pacemaker, and digitalis treatment with diabetes self-efficacy.

Mechanisms of Protective Effects of SGLT2 Inhibitors in Cardiovascular Disease and Renal Dysfunction

Type 2 diabetes mellitus is one of the most common forms of the disease worldwide. Hyperglycemia and insulin resistance play key roles in type 2 diabetes mellitus. Renal glucose reabsorption is an essential feature in glycaemic control. Kidneys filter 160 g of glucose daily in healthy subjects under euglycaemic conditions. The expanding epidemic of diabetes leads to a prevalence of diabetes-related cardiovascular disorders, in particular, heart failure and renal dysfunction. Cellular glucose uptake is a fundamental process for homeostasis, growth, and metabolism. In humans, three families of glucose transporters have been identified, including the glucose facilitators GLUTs, the sodium-glucose cotransporter SGLTs, and the recently identified SWEETs. Structures of the major isoforms of all three families were studied. Sodium-glucose cotransporter (SGLT2) provides most of the capacity for renal glucose reabsorption in the early proximal tubule. A number of cardiovascular outcome trials in patients with type 2 diabetes have been studied with SGLT2 inhibitors reducing cardiovascular morbidity and mortality. The current review article summarises these aspects and discusses possible mechanisms with SGLT2 inhibitors in protecting heart failure and renal dysfunction in diabetic patients. Through glucosuria, SGLT2 inhibitors reduce body weight and body fat, and shift substrate utilisation from carbohydrates to lipids and, possibly, ketone bodies. These pleiotropic effects of SGLT2 inhibitors are likely to have contributed to the results of the EMPA-REG OUTCOME trial in which the SGLT2 inhibitor, empagliflozin, slowed down the progression of chronic kidney disease and reduced major adverse cardiovascular events in high-risk individuals with type 2 diabetes. This review discusses the role of SGLT2 in the physiology and pathophysiology of renal glucose reabsorption and outlines the unexpected logic of inhibiting SGLT2 in the diabetic kidney.

Heart Failure in Type 2 Diabetes Mellitus

Patients with diabetes mellitus have >2× the risk for developing heart failure (HF; HF with reduced ejection fraction and HF with preserved ejection fraction). Cardiovascular outcomes, hospitalization, and prognosis are worse for patients with diabetes mellitus relative to those without. Beyond the structural and functional changes that characterize diabetic cardiomyopathy, a complex underlying, and interrelated pathophysiology exists. Despite the success of many commonly used antihyperglycemic therapies to lower hyperglycemia in type 2 diabetes mellitus the high prevalence of HF persists. This, therefore, raises the possibility that additional factors beyond glycemia might contribute to the increased HF risk in diabetes mellitus. This review summarizes the state of knowledge about the impact of existing antihyperglycemic therapies on HF and discusses potential mechanisms for beneficial or deleterious effects. Second, we review currently approved pharmacological therapies for HF and review evidence that addresses their efficacy in the context of diabetes mellitus. Dysregulation of many cellular mechanisms in multiple models of diabetic cardiomyopathy and in human hearts have been described. These include oxidative stress, inflammation, endoplasmic reticulum stress, aberrant insulin signaling, accumulation of advanced glycated end-products, altered autophagy, changes in myocardial substrate metabolism and mitochondrial bioenergetics, lipotoxicity, and altered signal transduction such as GRK (g-protein receptor kinase) signaling, renin angiotensin aldosterone signaling and β-2 adrenergic receptor signaling. These pathophysiological pathways might be amenable to pharmacological therapy to reduce the risk of HF in the context of type 2 diabetes mellitus. Successful targeting of these pathways could alter the prognosis and risk of HF beyond what is currently achieved using existing antihyperglycemic and HF therapeutics.

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.

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.

Implantable cardioverter-defibrillators in heart failure patients with reduced ejection fraction and diabetes

AIM

There is limited information on the outcomes after primary prevention implantable cardioverter-defibrillator (ICD) implantation in patients with heart failure (HF) and diabetes. This analysis evaluates the effectiveness of a strategy of ICD plus medical therapy vs. medical therapy alone among patients with HF and diabetes.

METHODS AND RESULTS

A patient-level combined-analysis was conducted from a combined dataset that included four primary prevention ICD trials of patients with HF or severely reduced ejection fractions: Multicenter Automatic Defibrillator Implantation Trial I (MADIT I), MADIT II, Defibrillators in Non-Ischemic Cardiomyopathy Treatment Evaluation (DEFINITE), and Sudden Cardiac Death in Heart Failure Trial (SCD-HeFT). In total, 3359 patients were included in the analysis. The primary outcome of interest was all-cause death. Compared with patients without diabetes (n = 2363), patients with diabetes (n = 996) were older and had a higher burden of cardiovascular risk factors. During a median follow-up of 2.6 years, 437 patients without diabetes died (178 with ICD vs. 259 without) and 280 patients with diabetes died (128 with ICD vs. 152 without). ICDs were associated with a reduced risk of all-cause mortality among patients without diabetes [hazard ratio (HR) 0.56, 95% confidence interval (CI) 0.46-0.67] but not among patients with diabetes (HR 0.88, 95% CI 0.7-1.12; interaction P = 0.015).

CONCLUSION

Among patients with HF and diabetes, primary prevention ICD in combination with medical therapy vs. medical therapy alone was not significantly associated with a reduced risk of all-cause death. Further studies are needed to evaluate the effectiveness of ICDs among patients with diabetes.

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.