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

Impact of Diabetes Mellitus on Outcomes in Patients with Left Ventricular Assist Devices

Heart failure (HF) represents a significant health burden in the United States, resulting in substantial mortality and healthcare costs. Through the array of treatment options available, including lifestyle modifications, medications, and implantable devices, HF management has evolved. Left ventricular assist devices (LVADs) have emerged as a crucial intervention, particularly in patients with advanced HF. However, the prevalence of comorbidities such as diabetes mellitus (DM) complicates treatment outcomes. By elucidating the impact of DM on LVAD outcomes, this review aims to inform clinical practice and enhance patient care strategies for individuals undergoing LVAD therapy. Patients with DM have higher rates of hypertension, dyslipidemia, peripheral vascular disease, and renal dysfunction, posing challenges to LVAD management. The macro/microvascular changes that occur in DM can lead to cardiomyopathy and HF. Glycemic control post LVAD implantation is a critical factor affecting patient outcomes. The recent literature has shown significant decreases in hemoglobin A1c following LVAD implantation, representing a possible bidirectional relationship between DM and LVADs; however, the clinical significance of this decrease is unclear. Furthermore, while some studies show increased short- and long-term mortality in patients with DM after LVAD implantation, there still is no literature consensus regarding either mortality or major adverse outcomes in DM patients.

Impact of Diabetes and Glycemia on Cardiac Improvement and Adverse Events Following Mechanical Circulatory Support

BACKGROUND

Type 2 diabetes is prevalent in cardiovascular disease and contributes to excess morbidity and mortality. We sought to investigate the effect of glycemia on functional cardiac improvement, morbidity, and mortality in durable left ventricular assist device (LVAD) recipients.

METHODS AND RESULTS

Consecutive patients with an LVAD were prospectively evaluated (n=531). After excluding patients missing pre-LVAD glycated hemoglobin (HbA1c) measurements or having inadequate post-LVAD follow-up, 375 patients were studied. To assess functional cardiac improvement, we used absolute left ventricular ejection fraction change (ΔLVEF: LVEF post-LVAD-LVEF pre-LVAD). We quantified the association of pre-LVAD HbA1c with ΔLVEF as the primary outcome, and all-cause mortality and LVAD-related adverse event rates (ischemic stroke/transient ischemic attack, intracerebral hemorrhage, gastrointestinal bleeding, LVAD-related infection, device thrombosis) as secondary outcomes. Last, we assessed HbA1c differences pre- and post-LVAD. Patients with type 2 diabetes were older, more likely men suffering ischemic cardiomyopathy, and had longer heart failure duration. Pre-LVAD HbA1c was inversely associated with ΔLVEF in patients with nonischemic cardiomyopathy but not in those with ischemic cardiomyopathy, after adjusting for age, sex, heart failure duration, and left ventricular end-diastolic diameter. Pre-LVAD HbA1c was not associated with all-cause mortality, but higher pre-LVAD HbA1c was shown to increase the risk of intracerebral hemorrhage, LVAD-related infection, and device thrombosis by 3 years on LVAD support (P<0.05 for all). HbA1c decreased from 6.68±1.52% pre-LVAD to 6.11±1.33% post-LVAD (P<0.001).

CONCLUSIONS

Type 2 diabetes and pre-LVAD glycemia modify the potential for functional cardiac improvement and the risk for adverse events on LVAD support. The degree and duration of pre-LVAD glycemic control optimization to favorably affect these outcomes warrants further investigation.

Propensity matched post-transplant survival in durable CF-axial pump BTT patients with and without diabetes: A UNOS database analysis

Diabetes and post-transplant survival have been linked. However, the impact on post-transplant survival of patients supported on Continuous Flow (CF) axial left ventricular assist devices (LVAD) as a bridge to transplant (BTT) with diabetes has not been widely studied. This study attempts to assess the impact of diabetes type II (DM type II) as a comorbidity influencing survival patterns in the post-cardiac transplant population supported on LVADs and to test if the presence of a pre- transplant durable LVAD acts as an independent risk factor in long-term post-transplant survival. The UNOS database population from 2004 to 2015 was used to construct the cohorts. A total of 21,032 were transplanted during this period. The transplant data were further queried to extract CF-axial flow pumps BTT (HMII-BTT) patients and patients who did not have VAD support before the transplant. A total of 4224 transplant recipients had HMII at the time of transplant, and 13,131 did not have VAD support. Propensity analysis was performed, and 4107 recipients of similar patient characteristics to those in the BTT group were selected for comparison. The patients with a VAD had significantly reduced survival at 2 years post-transplant (p = 0.00514) but this trend did not persist at 5 years (p = 0.0617) and 10 years post-transplant (p = 0.183). Patients with diabetes and a VAD significantly decreased survival at 2 years (p = 0.00204), 5 years (p = 0.00029), and 10 years (p = 0.00193). The presence of a durable LVAD is not an independent risk factor for long-term survival. Diabetes has a longstanding effect on the posttransplant survival of BTT patients.

Resolution of insulin resistance, lactic acidosis, and decrease in mechanical support requirements in patients post orthotopic heart transplant with the use of long-acting insulin glargine

OBJECTIVE

This study investigates the efficacy of using a long-acting insulin analog, along with the infusion of regular insulin, in achieving appropriate glycemic control and correcting lactic acidosis in patients post orthotopic heart transplant who demonstrate severe lactic acidosis and insulin resistance.

METHODS

This was a retrospective study of two cohorts (IRB FLA 20-003) of patients post orthotopic heart transplant with severe lactic acidosis and insulin resistance who were admitted to a tertiary intensive care unit and treated with (group 1) or without long-acting insulin analog (group 2) within the first 24 h of admission to the intensive care unit. Insulin resistance is defined as the requirement for intravenous regular insulin infusion of more than 20 units/h without the ability to achieve appropriate serum glucose level (120-180 mg /dL). Severe lactic acidosis is defined as arterial lactic acid of more than 10 mmol/L. The following parameters were investigated: time to correct lactic acidosis, duration of postoperative mechanical ventilation, the need for periprocedural mechanical circulatory support, and 28-day mortality.

RESULTS

The 28-day mortality was zero in both groups. Two patients required periprocedural mechanical support in group one, and ten patients required mechanical support in group two (RR = 0.224, 95%, confidence interval 0.052-0.95, Z = 2.029, p = 0.042). Three patients required tracheostomy in group one, and four patients required tracheostomy in group two (RR 0.84, 95 confidence interval 0.20-3.48, Z = 0.23, P = 0.81). Wilcoxon rank-sum test was used to compare time to correct lactic acidosis, with lactic acid resolution being faster in group one ([Formula: see text]1 = 19.7 h, SD ± 12.6 h [Formula: see text]2 = 29.3 h, SD ± 19.6 h, Z-value - 2.02, p-value 0.043). The duration of mechanical ventilation was less in group one ([Formula: see text]1 = 29 h, SD ± 12.7 h, [Formula: see text]2 = 55.1 h, SD ± 44.5 h, Z-value: - 1.92, p-value 0.05).

CONCLUSION

Administration of low-dose long-acting insulin glargine led to the resolution of the lactic acidosis, insulin resistance, and decreased requirements for pressor and inotropic support, which led to decreased need for mechanical circulatory support.

Disparities in Postdischarge Ambulatory Care Follow-Up Among Medicaid Beneficiaries With Diabetes, Hospitalized for Heart Failure

Background Ambulatory follow-up for all patients with heart failure (HF) is recommended within 7 to 14 days after hospital discharge to improve HF outcomes. We examined postdischarge ambulatory follow-up of patients with comorbid diabetes and HF from a low-income population in primary and specialty care. Methods and Results Adults with diabetes and first hospitalizations for HF, covered by Alabama Medicaid in 2010 to 2019, were included and the claims analyzed for ambulatory care use (any, primary care, cardiology, or endocrinology) within 60 days after discharge using restricted mean survival time regression and negative binomial regression. Among 9859 Medicaid-covered adults with diabetes and first hospitalization for HF (mean age, 53.7 years; SD, 9.2 years; 47.3% Black; 41.8% non-Hispanic White; 10.9% Hispanic/Other [Other included non-White Hispanic, American Indian, Pacific Islander and Asian adults]; 65.4% women, 34.6% men), 26.7% had an ambulatory visit within 0 to 7 days, 15.2% within 8 to 14 days, 31.3% within 15 to 60 days, and 26.8% had no visit; 71% saw a primary care physician and 12% a cardiology physician. Black and Hispanic/Other adults were less likely to have any postdischarge ambulatory visit (P<0.0001) or the visit was delayed (by 1.8 days, P=0.0006 and by 2.8 days, P=0.0016, respectively) and were less likely to see a primary care physician than non-Hispanic White adults (adjusted incidence rate ratio, 0.96 [95% CI, 0.91-1.00] and 0.91 [95% CI, 0.89-0.98]; respectively). Conclusions More than half of Medicaid-covered adults with diabetes and HF in Alabama did not receive guideline-concordant postdischarge care. Black and Hispanic/Other adults were less likely to receive recommended postdischarge care for comorbid diabetes and HF.

Insulinotropic Effects of Neprilysin and/or Angiotensin Receptor Inhibition in Mice

Treatment of heart failure with the angiotensin receptor-neprilysin inhibitor sacubitril/valsartan improved glycemic control in individuals with type 2 diabetes. The relative contribution of neprilysin inhibition versus angiotensin II receptor antagonism to this glycemic benefit remains unknown. Thus, we sought to determine the relative effects of the neprilysin inhibitor sacubitril versus the angiotensin II receptor blocker valsartan on beta-cell function and glucose homeostasis in a mouse model of reduced first-phase insulin secretion, and whether any beneficial effects are additive/synergistic when combined in sacubitril/valsartan. High fat-fed C57BL/6J mice treated with low-dose streptozotocin (or vehicle) were followed for eight weeks on high fat diet alone or supplemented with sacubitril, valsartan or sacubitril/valsartan. Body weight and fed glucose levels were assessed weekly. At the end of the treatment period, insulin release in response to intravenous glucose, insulin sensitivity, and beta-cell mass were determined. Sacubitril and valsartan, but not sacubitril/valsartan, lowered fasting and fed glucose levels and increased insulin release in diabetic mice. None of the drugs altered insulin sensitivity or beta-cell mass, but all reduced body weight gain. Effects of the drugs on insulin release were reproduced in angiotensin II-treated islets from lean C57BL/6J mice, suggesting the insulin response to each of the drugs is due to a direct effect on islets and mechanisms therein. In summary, sacubitril and valsartan each exert beneficial insulinotropic, glycemic and weight-reducing effects in obese and/or diabetic mice when administered alone; however, when combined, mechanisms within the islet contribute to their inability to enhance insulin release.

Cardiac Surgery in Advanced Heart Failure

Mechanical circulatory support and heart transplantation are established surgical options for treatment of advanced heart failure. Since the prevalence of advanced heart failure is progressively increasing, there is a clear need to treat more patients with mechanical circulatory support and to increase the number of heart transplantations. This narrative review summarizes recent progress in surgical treatment options of advanced heart failure and proposes an algorithm for treatment of the advanced heart failure patient at >65 years of age.

Improvement in Metabolic Co-Morbidities after Implantation of CardioMEMS in Patients with Heart Failure with Preserved Ejection Fraction Phenotype

Background: Heart failure with preserved ejection fraction (HFpEF) patients often have other comorbidities, including obesity, dyslipidemia, hypertension, and diabetes, comprising the metabolic syndrome. The impacts of hemodynamic monitoring via CardioMEMS on these co-morbidities remain unknown. Methods: A retrospective analysis of 29 patients with HFpEF (EF 45% or greater) and CardioMEMS was performed at a single center. Weight, body mass index (BMI), systolic blood pressures (SBP), high-density lipoprotein (HDL), triglycerides (TGL), hemoglobin A1C (HbA1c), and pulmonary artery diastolic pressures (PADP) were assessed at baseline and six months post-implant. Paired t-tests and the Wilcoxon signed-rank test were used, as appropriate, to test differences between time points. Results: These patients were 69% female, with a mean age of 73 years, and 62% had non-ischaemic cardiomyopathies (NICM). At the time of CardioMEMS implantation, average PADP was 20.1 mmHg ± 5.7, weight was 102.6 kg ± 22.7, BMI was 38.0 kg/m² ± 8.3, SBP was 135 mmHg ± 19, HDL was 42.4 mg/dL ± 11.3, and median TGL was 130 mg/dL (100, 180). At six months we witnessed a decrease by 20.9% in PADP to 15.9 mmHg ± 5.8, (p < 0.001). In addition, the following was noted: weight decreased by 2.5% to 100.0 kg ± 23.2, (p = 0.006), BMI reduced by 2.6% to 37.0 ± 8.2, (p = 0.002), SBP decreased by 6.7% to 126 mmHg ± 16 (p < 0.001), HDL increased by 10.8% to 47 mg/dL ± 11.9 (p < 0.001), and TGL decreased by 15.4% to 110 mg/dL (105, 135) (p = 0.001). 62% of patients were diabetic with no significant improvements in HbA1C values at the 6-month follow-up. Conclusion: The utilization of CardioMEMS to optimize PADP results in an improvement in the comorbidities associated with the metabolic syndrome. Further studies are warranted to validate these findings and delineate clinical significance.

Skeletal muscle atrophy in heart failure with diabetes: from molecular mechanisms to clinical evidence

Two highly prevalent and growing global diseases impacted by skeletal muscle atrophy are chronic heart failure (HF) and type 2 diabetes mellitus (DM). The presence of either condition increases the likelihood of developing the other, with recent studies revealing a large and relatively poorly characterized clinical population of patients with coexistent HF and DM (HFDM). HFDM results in worse symptoms and poorer clinical outcomes compared with DM or HF alone, and cardiovascular-focused disease-modifying agents have proven less effective in HFDM indicating a key role of the periphery. This review combines current clinical knowledge and basic biological mechanisms to address the critical emergence of skeletal muscle atrophy in patients with HFDM as a key driver of symptoms. We discuss how the degree of skeletal muscle wasting in patients with HFDM is likely underpinned by a variety of mechanisms that include mitochondrial dysfunction, insulin resistance, inflammation, and lipotoxicity. Given many atrophic triggers (e.g. ubiquitin proteasome/autophagy/calpain activity and supressed IGF1-Akt-mTORC1 signalling) are linked to increased production of reactive oxygen species, we speculate that a higher pro-oxidative state in HFDM could be a unifying mechanism that promotes accelerated fibre atrophy. Overall, our proposal is that patients with HFDM represent a unique clinical population, prompting a review of treatment strategies including further focus on elucidating potential mechanisms and therapeutic targets of muscle atrophy in these distinct patients.

Effect of Empagliflozin on Cardiovascular and Renal Outcomes in Patients With Heart Failure by Baseline Diabetes Status: Results From the EMPEROR-Reduced Trial

Supplemental Digital Content is available in the text.

Sodium-glucose cotransporter 2 inhibitors improve outcomes in patients with heart failure with reduced ejection fraction, but additional information is needed about whether glycemic status influences the magnitude of their benefits on heart failure and renal events.

Adiponectin in heart failure

The adipose tissue, apart from storing energy, plays a role of an endocrine organ. One of the most important adipokines secreted by adipose tissue is adiponectin, which is also produced by cardiomyocytes and connective tissue cells within the heart. Adiponectin is known for its beneficial effect on the metabolism and cardiovascular system and its low level is a factor of development of many cardiovascular diseases. Paradoxically, in the course of heart failure, adiponectin level gradually increases with the severity of the disease and higher adiponectin level is a factor of poor prognosis. As a result, there is a growing interest in adiponectin as a marker of heart failure progression and a predictor of prognosis in the course of this disease.

Myocardial Involvement in Chagas Disease and Insulin Resistance: A Non-Metabolic Model of Cardiomyopathy

Background:

Heart failure (HF) and type 2 Diabetes Mellitus (T2DM) represent two chronic interrelated conditions accounting for significant morbidity and mortality worldwide. Insulin resistance (IR) has been identified as a risk factor for HF; however, the risk of IR that HF confers has not been well elucidated. The present study aims to analyze the association between myocardial involvement in Chronic Chagas Cardiomyopathy (CCM) and IR, taking advantage of this non-metabolic model of the disease.

Methods:

Cross-sectional study performed during the period 2015–2016. Adults with a serological diagnosis of Chagas disease were included, being divided into two groups: CCM and non-CCM. IR was determined by HOMA-IR index. Bivariate analysis and multivariate logistic regression were performed to determine the association between IR as an outcome and CCM as primary exposure.

Results:

200 patients were included in the study, with a mean age of 54.7 years and a female predominance (53.5%). Seventy-four (37.0%) patients were found to have IR, with a median HOMA-IR index of 3.9 (Q1 = 3.1; Q3 = 5.1). Multiple metabolic variables were significantly associated with IR. In a model analyzing only individuals with an altered HWI, an evident association between CCM and IR was observed (OR 4.08; 95% CI 1.55–10.73, p = 0.004).

Conclusion:

CCM was significantly associated with IR in patients with an altered HWI. The presence of this association in a non-metabolic model of HF (in which the myocardial involvement is expected to be mediated mostly by the parasitic infection) may support the evidence of a direct unidirectional correlation between this last and IR.

Metabolic Dysfunction in Continuous-Flow Left Ventricular Assist Devices Patients and Outcomes

Background

Metabolic impairment is common in heart failure patients. Continuous‐flow left ventricular assist devices (CF‐LVADs) improve hemodynamics and outcomes in patients with advanced heart failure; however, the effect of CF‐LVADs on metabolic status is unknown. This study aims to evaluate the changes in metabolic status following CF‐LVAD implantation and measure the correlation of metabolic status with outcomes.

Methods and Results

Prospective data on CF‐LVAD patients were obtained. Metabolic evaluation, including hemoglobin A1C, free and total testosterone, thyroid‐stimulating hormone (TSH), and free T4, was obtained before and at multiple time points following implantation. Patients with nonelevated thyroid‐stimulating hormone and normal hemoglobin A1C and testosterone levels were defined as having normal metabolic status. Baseline characteristics, hemodynamics, and outcomes were collected. One hundred six patients were studied, of which 56 had paired data at baseline and 1‐ to 3‐month follow‐up. Before implantation, 75% of patients had insulin resistance, 86% of men and 39% of women had low free testosterone, and 44% of patients had abnormal thyroid function. There was a significant improvement in hemoglobin A1C, free testosterone, and thyroid‐stimulating hormone following implantation (P<0.001 for all). Patients with normal hemoglobin A1C (<5.7%) following implantation had higher 1‐year survival free of heart failure readmissions (78% versus 23%; P<0.001). Patients with normal metabolic status following implantation also had higher 1‐year survival free of heart failure readmissions (92% versus 54%; P=0.04).

Conclusions

Metabolic dysfunction is highly prevalent in advanced heart failure patients and improves after CF‐LVAD implantation. Normal metabolic status is associated with a significantly higher rate of 1‐year survival free of heart failure readmissions.

2019 EACTS Expert Consensus on long-term mechanical circulatory support

Long-term mechanical circulatory support (LT-MCS) is an important treatment modality for patients with severe heart failure. Different devices are available, and many-sometimes contradictory-observations regarding patient selection, surgical techniques, perioperative management and follow-up have been published. With the growing expertise in this field, the European Association for Cardio-Thoracic Surgery (EACTS) recognized a need for a structured multidisciplinary consensus about the approach to patients with LT-MCS. However, the evidence published so far is insufficient to allow for generation of meaningful guidelines complying with EACTS requirements. Instead, the EACTS presents an expert opinion in the LT-MCS field. This expert opinion addresses patient evaluation and preoperative optimization as well as management of cardiac and non-cardiac comorbidities. Further, extensive operative implantation techniques are summarized and evaluated by leading experts, depending on both patient characteristics and device selection. The faculty recognized that postoperative management is multidisciplinary and includes aspects of intensive care unit stay, rehabilitation, ambulatory care, myocardial recovery and end-of-life care and mirrored this fact in this paper. Additionally, the opinions of experts on diagnosis and management of adverse events including bleeding, cerebrovascular accidents and device malfunction are presented. In this expert consensus, the evidence for the complete management from patient selection to end-of-life care is carefully reviewed with the aim of guiding clinicians in optimizing management of patients considered for or supported by an LT-MCS device.

Implantation of Left Ventricular Assist Device Results in Immediate Improvement of Glucose Metabolism in Patients With and Without Diabetes Mellitus

BACKGROUND

Several studies demonstrated improvement in diabetes mellitus (DM) following left ventricular assist device (LVAD) implantation, but the timing of these changes has not been identified. We sought to determine if favourable metabolic changes occur immediately, within the initial hospitalisation following LVAD implantation. We also wanted to see whether favourable changes in glucose metabolism occur in patients without diabetes.

METHODS

This is a retrospective analysis of patients receiving LVADs at our institution. We collected the data on fasting blood glucose (FBG) and total daily insulin requirements before the LVAD implantation and before the discharge. Patients served as their own controls.

RESULTS

We studied 70 consecutive patients, half of them diabetic. In both diabetics and non-diabetics there was a significant reduction in FBG after LVAD implantation. In diabetic patients, there was an overall reduction in insulin requirements from the average 29.2 units of insulin per day before the LVAD to 16.2 units per day (p=0.038) before discharge. Specifically, insulin requirement decreased in 16 patients by a median of 25.2 units per day (the interquartile range [IQR)]: -47.8 to -9.2), increased in 10 patients (by 7.3 units/day, IQR 0.7 to 15.3), and remained unchanged in six patients.

CONCLUSIONS

Favourable metabolic changes on LVAD support occurred almost immediately, within initial hospitalisation, in diabetics and non-diabetics alike. Decline in insulin requirements should be considered when managing diabetics following LVAD implantation.

Type 2 Diabetes Mellitus and Heart Failure: A Scientific Statement From the American Heart Association and the Heart Failure Society of America: This statement does not represent an update of the 2017 ACC/AHA/HFSA heart failure guideline update

Type 2 diabetes mellitus is a risk factor for incident heart failure and increases the risk of morbidity and mortality in patients with established disease. Secular trends in the prevalence of diabetes mellitus and heart failure forecast a growing burden of disease and underscore the need for effective therapeutic strategies. Recent clinical trials have demonstrated the shared pathophysiology between diabetes mellitus and heart failure, the synergistic effect of managing both conditions, and the potential for diabetes mellitus therapies to modulate the risk of heart failure outcomes. This scientific statement on diabetes mellitus and heart failure summarizes the epidemiology, pathophysiology, and impact of diabetes mellitus and its control on outcomes in heart failure; reviews the approach to pharmacological therapy and lifestyle modification in patients with diabetes mellitus and heart failure; highlights the value of multidisciplinary interventions to improve clinical outcomes in this population; and outlines priorities for future research.

Type 2 Diabetes Mellitus and Heart Failure, A Scientific Statement From the American Heart Association and Heart Failure Society of America

Type 2 diabetes mellitus is a risk factor for incident heart failure and increases the risk of morbidity and mortality in patients with established disease. Secular trends in the prevalence of diabetes mellitus and heart failure forecast a growing burden of disease and underscore the need for effective therapeutic strategies. Recent clinical trials have demonstrated the shared pathophysiology between diabetes mellitus and heart failure, the synergistic effect of managing both conditions, and the potential for diabetes mellitus therapies to modulate the risk of heart failure outcomes. This scientific statement on diabetes mellitus and heart failure summarizes the epidemiology, pathophysiology, and impact of diabetes mellitus and its control on outcomes in heart failure; reviews the approach to pharmacological therapy and lifestyle modification in patients with diabetes mellitus and heart failure; highlights the value of multidisciplinary interventions to improve clinical outcomes in this population; and outlines priorities for future research.

Clinical Impact of Diabetes Mellitus on Short-Term Outcomes andIn-Hospital Mortality of Cardiac Mechanical Support with Left Ventricular Assist Device (LVAD): A Retrospective Study from a National Database

BACKGROUND

Cardiac support with left ventricular assist devices (LVAD) is a growing field. LVAD are increasingly used for patients with advanced congestive heart failure. Multiple studies have evaluated the outcomes of cardiac support with LVAD in patients with and without diabetes mellitus (DM), yet we still have conflicting results. This study aimed to assess the clinical impact of diabetes mellitus on patients undergoing cardiac support with LVAD.

METHODS

Diabetic patients who underwent mechanical support with LVAD between 2011 and 2014 were identified in the National Inpatient Sample (NIS) database using the International Classification of Diseases, 9th Revision, Clinical Modification (ICD-9-CM). The primary outcome was the effect of diabetes mellitus on inpatient mortality. Secondary outcomes were the impact of diabetes on other immediate post-LVAD complications and the cost of hospitalization. Multivariable logistic regression models analysis was performed to address potential confounding.

RESULTS

After adjusting for patient-level and hospital-level characteristics, diabetic patients who underwent cardiac support with LVAD have no significant increase in in-hospital mortality (OR: 0.79, 95% CI (0.57-1.10), p = 0.166), post-LVAD short-term complications and cost of hospitalization (OR: 0.97, 95% CI (0.93-1.01), p = 0.102).

CONCLUSION

Cardiac mechanical support with LVAD implantation is feasible and relatively safe in patients with diabetes and stage-D heart failure as a bridge for transplantation or as destination therapy for patients who are not candidates for transplantation. However, further trials and studies using bigger study sample and more comprehensive databases, need to be conducted for a stronger and more valid evidence.

Left ventricular assist device implantation improves glycaemic control: a systematic review and meta-analysis

AIMS

Heart failure (HF) and diabetes mellitus (DM) often coexist and have bidirectional association. Advanced HF is associated with worsened glycaemic control. This meta-analysis investigated the effects of left ventricular assist device (LVAD) implantation on markers of DM control.

METHODS AND RESULTS

We performed a systematic search of MEDLINE and Cochrane through October 2017 to identify studies evaluating advanced HF patients who had received an LVAD and reported markers of glycaemic control. The primary outcome was glycosylated haemoglobin A1c (HbA1c), and the secondary outcomes included fasting glucose, daily insulin requirements, and body mass index (BMI). Outcomes were pooled using a Hartung-Knapp random-effects model producing a mean difference (MD) and 95% confidence interval (CI). Thirteen studies, including 820 participants, were included. HbA1c was 1.23% lower following LVAD implantation (95% CI -1.49 to -0.98). Greater HbA1c reductions were seen with higher pre-LVAD values. Similarly, fasting plasma glucose (-24.4 mg/dL, 95% CI -33.4 to -15.5), daily insulin requirements (-18.8 units, 95% CI -28.8 to -8.7), and serum creatinine levels (MD -0.20, 95% CI -0.35 to -0.06) were significantly lower than pre-LVAD levels. We saw no difference in BMI (MD 0.09, 95% CI -1.24 to 1.42).

CONCLUSIONS

LVAD implantation was associated with significant improvement in HbA1c, fasting plasma glucose, and daily insulin need in advanced HF patients.

The Metabolic Syndrome, Cardiovascular Fitness and Survival in Patients With Advanced Systolic Heart Failure

The metabolic syndrome (MetS), which incorporates insulin resistance, visceral adiposity, and dyslipidemia, is an independent risk factor for incident heart failure (HF), but the impact on survival is uncertain. We sought to determine the relation between the metabolic syndrome and survival in ambulatory systolic HF patients and the impact of MetS on cardiopulmonary exercise test (CPET). We identified adults with ejection fraction ≤40% who underwent CPETs between 2000 and 2011. Baseline MetS status was defined by 3 or more of: (1) Triglycerides ≥150 mg/dl; (2) High density lipoprotein <40 mg/dl males or <50 mg/dl females; (3) Diabetes mellitus; (4) Hypertension; (5) Body mass index ≥35 kg/m². Minimally-adjusted (for age, sex, transplantation and left ventricular assist device implantation) and fully-adjusted Cox proportional hazards models were constructed for all-cause mortality. MetS prevalence was 37% (716 of 1,953) and median follow-up 5 years. Mortality was 36% for +MetS and 29% for -MetS (p = 0.006), with highest mortality in the subgroup with both MetS plus diabetes (39%). The minimally-adjusted hazard ratio for mortality with MetS was 1.27 (95% confidence interval, 1.08 to 1.49, p = 0.004). After adjustment, MetS was no longer independently associated with mortality (hazard ratio 1.01, 95% confidence interval 0.85 to 1.19, p = 0.921). Patients with MetS achieved poorer CPET performance compared and MetS was independently associated with a lower peak VO₂. MetS was associated with a higher hazard of mortality in the minimally-adjusted model, which was primarily driven by the unfavorable impact of diabetes on mortality, but this association was no longer significant after full adjustment. In conclusion, there was no independent association between MetS and survival in an ambulatory systolic HF population.

Revisiting the Diabetes-Heart Failure Connection

PURPOSE OF THE REVIEW

To summarize current clinical data investigating the link between diabetes and heart failure pathophysiology, the association of glucose control with heart failure, and the impact of current antihyperglycemic drugs on heart failure.

RECENT FINDINGS

Although heart failure is one of the most prevalent outcomes occurring in real life and cardiovascular outcome trials, insufficient attention was given to this condition in diabetes research over the last decades. With both beneficial and detrimental findings for heart failure hospitalization in the health authority-mandated outcome trials for new antihyperglycemic agents, research on heart failure and its interplay with diabetes mellitus gained momentum. Diabetes mellitus and heart failure are both prevalent and intertwined conditions. While currently available heart failure therapies have a similar degree of effectiveness in patients with and without diabetes, the choice of glucose-lowering agents can substantially affect heart failure-related outcome.

Perspectives on diabetes mortality as the result of residual confounding and reverse causality by common disease

Type 2 diabetes (T2D) is associated with major global health burdens, including 2 to 4 times increased rates of morbidity and mortality from cardiovascular disease. However, T2D remains an exclusion diagnosis in individuals with arbitrarily elevated blood-glucose levels. While it is well-established that diabetes is associated with an elevated risk of cardiovascular disease and cancer, it has recently been shown that heart failure and cancer may precede, and even contribute to, the development of T2D. In the present review, we have summarized these findings and discuss their potential implications for our understanding of the T2D disease entity, including its treatment and associated increased mortality. We suggest that the existence of a hitherto unrecognized distinct T2D subtype, secondary to heart failure and/or cancer, may substantially contribute to the excess mortality reported in T2D patients with mild disease. Treatment and clinical care of this subtype needs to be defined separately from the general T2D phenotype.

Influence of Diabetes Mellitus on Outcomes in Patients After Left Ventricular Assist Device Implantation

BACKGROUND

Despite previous studies, the mortality risk of patients with diabetes mellitus after left ventricular assist device (LVAD) implant remains unclear. In addition, the relationship between the degree of glycemic control and long-term mortality risk in LVAD patients with diabetes has not been established.

METHODS

Ninety-five nondiabetic patients and 96 diabetic patients from the University of Rochester Medical Center who received a HeartMate II (Thoratec, Pleasanton, CA) continuous-flow LVAD between May 2008 and June 2014 were included in this study. The primary outcome was all-cause mortality. Secondary outcomes included rates of infection, neurologic dysfunction, renal dysfunction, and rehospitalization. Kaplan-Meier survival analyses and Cox models were utilized.

RESULTS

During follow-up, 32 diabetic patients (33%) and 15 nondiabetic patients (16%) died after LVAD implantation. Cumulative probability of death was higher for diabetic patients when compared with nondiabetic patients (42% versus 21% at 3 years, p = 0.013). There were no significant differences in overall rates of infection, neurologic dysfunction, and rehospitalization between the two groups. However, after an initial secondary outcome event, diabetic patients continued to have a higher mortality rate when compared with nondiabetic patients. There was no statistically significant difference in the risk of death between diabetic patients with pre-LVAD hemoglobin A1c less than 7.0% and diabetic patients with pre-LVAD hemoglobin A1c 7.0% or greater (hazard ratio 1.71, 95% confidence interval: 0.72 to 4.08, p = 0.223).

CONCLUSIONS

Diabetic patients who underwent LVAD implantation had a higher risk of death compared with nondiabetic patients. Adverse event rates did not differ between the two groups. Finally, the degree of glycemic control in diabetic patients before LVAD was not found to influence mortality.

Impact of Diabetes Mellitus on Outcomes in Patients Supported With Left Ventricular Assist Devices

Background

Diabetes mellitus (DM) is a risk factor for morbidity and mortality in patients with heart failure. The effect of DM on post–left ventricular assist device (LVAD) implantation outcomes is unclear. This study sought to investigate whether patients with DM had worse outcomes than patients without DM after LVAD implantation and whether LVAD support resulted in a better control of DM.

Methods and Results

We retrospectively reviewed 341 consecutive adults who underwent implantation of LVAD from 2007 to 2016. Patient characteristics and adverse events were studied and compared between patients with and without DM. One hundred thirty-one patients (38%) had DM. Compared with patients without DM, those with DM had higher rates of ischemic cardiomyopathy, LVAD implantation as destination therapy, and increased baseline body mass index. In a proportional hazards (Cox) model with adjustment for relevant covariates and median follow-up of 16.1 months, DM was associated with increased risk of all-cause mortality (hazard ratio, 1.73; 95% confidence interval: 1.18–2.53; P =0.005) and increased risk of nonfatal LVAD-related complications, including a composite of stroke, pump thrombosis, and device infection (hazard ratio, 2.1; 95% confidence interval: 1.35–3.18; P =0.001). Preoperative hemoglobin A1c was not significantly associated with mortality or adverse events among patients with DM. LVAD implantation resulted in a remarkable decrease in hemoglobin A1c levels (7.4±1.9 pre-LVAD versus 6.0±1.5 and 6.3±1.4 after 3 and 12 months post-LVAD, respectively; P <0.0001) and a significant reduction in requirements of DM medications.

Conclusions

DM is associated with increased rates of all-cause mortality and major adverse events despite favorable glycemic control after LVAD implantation.

Activation and Inhibition of Sodium-Hydrogen Exchanger Is a Mechanism That Links the Pathophysiology and Treatment of Diabetes Mellitus With That of Heart Failure

The mechanisms underlying the progression of diabetes mellitus and heart failure are closely intertwined, such that worsening of one condition is frequently accompanied by worsening of the other; the degree of clinical acceleration is marked when the 2 coexist. Activation of the sodium-hydrogen exchanger in the heart and vasculature (NHE1 isoform) and the kidneys (NHE3 isoform) may serve as a common mechanism that links both disorders and may underlie their interplay. Insulin insensitivity and adipokine abnormalities (the hallmarks of type 2 diabetes mellitus) are characteristic features of heart failure; conversely, neurohormonal systems activated in heart failure (norepinephrine, angiotensin II, aldosterone, and neprilysin) impair insulin sensitivity and contribute to microvascular disease in diabetes mellitus. Each of these neurohormonal derangements may act through increased activity of both NHE1 and NHE3. Drugs used to treat diabetes mellitus may favorably affect the pathophysiological mechanisms of heart failure by inhibiting either or both NHE isoforms, and drugs used to treat heart failure may have beneficial effects on glucose tolerance and the complications of diabetes mellitus by interfering with the actions of NHE1 and NHE3. The efficacy of NHE inhibitors on the risk of cardiovascular events may be enhanced when heart failure and glucose intolerance coexist and may be attenuated when drugs with NHE inhibitory actions are given concomitantly. Therefore, the sodium-hydrogen exchanger may play a central role in the interplay of diabetes mellitus and heart failure, contribute to the physiological and clinical progression of both diseases, and explain certain drug-drug and drug-disease interactions that have been reported in large-scale randomized clinical trials.

Recovery of Serum Cholesterol Predicts Survival After Left Ventricular Assist Device Implantation

BACKGROUND

Advanced systolic heart failure is associated with myocardial and systemic metabolic abnormalities, including low levels of total cholesterol and low-density lipoprotein. Low cholesterol and low-density lipoprotein have been associated with greater mortality in heart failure. Implantation of a left ventricular assist device (LVAD) reverses some of the metabolic derangements of advanced heart failure.

METHODS AND RESULTS

A cohort was retrospectively assembled from 2 high-volume implantation centers, totaling 295 continuous-flow LVAD recipients with ≥2 cholesterol values available. The cohort was predominantly bridge-to-transplantation (67%), with median age of 59 years and 49% ischemic heart failure cause. Total cholesterol, low-density lipoprotein, high-density lipoprotein, and triglyceride levels all significantly increased after LVAD implantation (median values from implantation to 3 months post implantation 125-150 mg/dL, 67-85 mg/dL, 32-42 mg/dL, and 97-126 mg/dL, respectively). On Cox proportional hazards modeling, patients achieving recovery of total cholesterol levels, defined as a median or greater change from pre implantation to 3 months post-LVAD implantation, had significantly better unadjusted survival (hazard ratio, 0.445; 95% confidence interval, 0.212-0.932) and adjusted survival (hazard ratio, 0.241; 95% confidence interval, 0.092-0.628) than those without cholesterol recovery after LVAD implantation. The continuous variable of total cholesterol at 3 months post implantation and the cholesterol increase from pre implantation to 3 months were also both significantly associated with survival during LVAD support.

CONCLUSIONS

Initiation of continuous-flow LVAD support was associated with significant recovery of all 4 lipid variables. Patients with a greater increase in total cholesterol by 3 months post implantation had superior survival during LVAD support.

Insulin and β Adrenergic Receptor Signaling: Crosstalk in Heart

Recent advances show that insulin may affect β adrenergic receptor (βAR) signaling in the heart to modulate cardiac function in clinically relevant states, such as diabetes mellitus (DM) and heart failure (HF). Conversely, activation of βAR regulates cardiac glucose uptake and promotes insulin resistance (IR) in HF. Here, we discuss the recent characterization of the interaction between the cardiac insulin receptor (InsR) and βAR in the myocardium, in which insulin stimulation crosstalks with cardiac βAR via InsR substrate (IRS)-dependent and G-protein receptor kinase 2 (GRK2)-mediated phosphorylation of β₂AR. The insulin-induced phosphorylation promotes β₂AR coupling to G_i and expression of phosphodiesterase 4D, which both inhibit cardiac adrenergic signaling and compromise cardiac contractile function. These recent developments could support new approaches for the effective prevention or treatment of obesity- or DM-related HF.

Is Diabetes Mellitus a Risk Factor for Poor Outcomes after Left Ventricular Assist Device Placement?

Diabetes mellitus is associated with adverse outcomes in patients with cardiovascular diseases, including heart failure. Left ventricular assist devices (LVADs) are increasingly used as life-saving therapy for advanced heart failure. The effects of pre-LVAD diabetes on long-term outcomes after LVAD implantation are not well understood. In this study, we retrospectively evaluated the effect of existing diabetes on post-LVAD outcomes. Data on 288 LVAD recipients from 2006 through 2013 were reviewed. Patients were stratified in accordance with their histories of diabetes. Baseline demographic, laboratory, hemodynamic, and echocardiographic information before LVAD placement were reviewed, together with the post-LVAD incidence of major adverse outcomes. Kaplan-Meier analysis and Cox regression analysis were performed. Our cohort comprised 122 patients with diabetes and 166 patients without. The mean glycosylated hemoglobin A_1c level in the diabetes group was 7.4% ± 1.6%. Diabetic patients at baseline had a more adverse medical profile than did nondiabetic patients. There were no differences in major outcomes between the 2 groups other than a higher incidence of hemolysis in the diabetes group: 12 (10%) vs 5 (3%); P=0.02. There was no difference in survival outcomes between the groups. Diabetic patients did not have worse survival or more adverse outcomes than did nondiabetic patients in this study, perhaps because of improved diabetes control, or improvement in biochemical derangements after normalization of cardiac output with LVAD therapy. A diagnosis of diabetes was an independent predictor of hemolysis. Further studies to evaluate the link between hemolysis and diabetes are indicated.

Positive Impact of Continuous-Flow Left Ventricular Assist Device Implantation on Glycemic Control in Patients with Type 2 Diabetes Mellitus and Advanced Chronic Systolic Heart Failure

STUDY OBJECTIVE

To evaluate the impact of continuous-flow left ventricular assist device (LVAD) implantation on glycemic control in patients with type 2 diabetes mellitus and advanced chronic systolic heart failure.

DESIGN

Retrospective medical record review.

SETTING

Large academic tertiary and quaternary care hospital.

PATIENTS

Eighty-three adults with type 2 diabetes mellitus and advanced chronic systolic heart failure who underwent implantation of a continuous-flow LVAD between July 1, 2008, and June 30, 2013.

MEASUREMENTS AND MAIN RESULTS

Baseline demographic data and laboratory values pertinent to glycemic control (hemoglobin A_1c [A1C], total daily insulin requirements, noninsulin antidiabetic medication use, and body mass index [BMI]) were collected for each patient. Pre-LVAD data were compared with data obtained during the 24 months after LVAD implantation. The mean age of the study population was 61.3 years, 70% were men, and 63% had ischemic cardiomyopathy. The first available mean ± SD A1C after LVAD implantation was 6.21 ± 1.5% at a median of 4.8 months (interquartile range 3.3-8.9), which represented a significant decrease from the pre-LVAD A1C of 7.46 ± 1.5% (p<0.001). Average daily insulin requirements decreased by 22.9 units at the end of 24 months (p<0.001). Over half of patients with prescriptions for noninsulin antidiabetic medications were able to discontinue therapy by the end of the study. Of note, BMI increased in the second year after LVAD implantation from a baseline of 32.3 kg/m² to 34.9 kg/m² (p=0.004). Regression analysis revealed that baseline A1C was the only independent predictor of change in A1C.

CONCLUSION

LVAD implantation was associated with a significant improvement in glycemic control. Further prospective studies are needed to evaluate the long-term impact of LVAD implantation on the clinical course of diabetes.

Retinol-Binding Protein 4 Induces Cardiomyocyte Hypertrophy by Activating TLR4/MyD88 Pathway

Insulin resistance plays a major role in the development and progression of cardiac hypertrophy and heart failure. Heart failure in turn promotes insulin resistance and increases the risk for diabetes. The vicious cycle determines significant mortality in patients with heart failure and diabetes. However, the underlying mechanisms for the vicious cycle are not fully elucidated. Here we show that circulating levels and adipose expression of retinol-binding protein 4 (RBP4), an adipokine that contributes to systemic insulin resistance, were elevated in cardiac hypertrophy induced by transverse aortic constriction and angiotensin-II (Ang-II) infusion. Ang-II increased RBP4 expression in adipocytes, which was abolished by losartan, an Ang-II receptor blocker. The elevated RBP4 in cardiac hypertrophy may have pathophysiological consequences because RBP4 increased cell size, enhanced protein synthesis, and elevated the expression of hypertrophic markers including Anp, Bnp, and Myh7 in primary cardiomyocytes. Mechanistically, RBP4 induced the expression and activity of toll-like receptor 4 (TLR4) and myeloid differentiation primary response gene 88 (MyD88) in cardiomyocytes, resulting in enhanced inflammation and reactive oxygen species production. Inhibition or knockdown of the TLR4/MyD88 pathway attenuated inflammatory and hypertrophic responses to RBP4 stimulation. Importantly, RBP4 also reduced the expression of glucose transporter-4 and impaired insulin-stimulated glucose uptake in cardiomyocytes. This impairment was ameliorated in cardiomyocytes from TLR4 knockout mice. Therefore, RBP4 may be a critical modulator promoting the vicious cycle of insulin resistance and heart failure by activating TLR4/MyD88-mediated inflammatory pathways. Potentially, lowering RBP4 might break the vicious cycle and improve both insulin resistance and cardiac hypertrophy.

Efficacy of CD34+ Stem Cell Therapy in Nonischemic Dilated Cardiomyopathy Is Absent in Patients With Diabetes but Preserved in Patients With Insulin Resistance

We evaluated the association of diabetes and insulin resistance with the response to cell therapy in patients with nonischemic dilated cardiomyopathy (DCM). A total of 45 outpatients with DCM received granulocyte colony-stimulating factor for 5 days. CD34(+) cells were then collected by apheresis and injected transendocardially. Twelve patients had diabetes mellitus (DM group), 17 had insulin resistance (IR group), and 16 displayed normal glucose metabolism (no-IR group). After stimulation, we found higher numbers of CD34(+) cells in the IR group (94 ± 73 × 10(6) cells per liter) than in the no-IR group (54 ± 35 × 10(6) cells per liter) or DM group (31 ± 20 × 10(6) cells per liter; p = .005). Similarly, apheresis yielded the highest numbers of CD34(+) cells in the IR group (IR group, 216 ± 110 × 10(6) cells; no-IR group, 127 ± 82 × 10(6) cells; DM group, 77 ± 83 × 10(6) cells; p = .002). Six months after cell therapy, we found an increase in left ventricular ejection fraction in the IR group (+5.6% ± 6.9%) and the no-IR group (+4.4% ± 7.2%) but not in the DM group (-0.9% ± 5.4%; p = .035). The N-terminal pro-brain natriuretic peptide levels decreased in the IR and no-IR groups, but not in the DM group (-606 ± 850 pg/ml; -698 ± 1,105 pg/ml; and +238 ± 963 pg/ml, respectively; p = .034). Transendocardial CD34(+) cell therapy appears to be ineffective in DCM patients with diabetes. IR was associated with improved CD34(+) stem cell mobilization and a preserved clinical response to cell therapy.

SIGNIFICANCE

The present study is the first clinical study directly evaluating the effects of altered glucose metabolism on the efficacy of CD34(+) stem cell therapy in patients with nonischemic dilated cardiomyopathy. The results offer critical insights into the physiology of stem cell mobilization in heart failure and possibly an explanation for the often conflicting results obtained with stem cell therapy for heart failure. These results demonstrate that patients with dilated cardiomyopathy and diabetes do not benefit from autologous CD34(+) cell therapy. This finding could serve as a useful tool when selecting heart failure patients for future clinical studies in the field of stem cell therapy.

Treatment persistence after initiating basal insulin in type 2 diabetes patients: A primary care database analysis

AIMS

To compare persistence and its predictors in type 2 diabetes patients in primary care, initiating either basal supported oral therapy (BOT) or intensified conventional therapy (ICT) with glargine, detemir, or NPH insulin.

METHODS

In the BOT cohort, 1398 glargine (mean age: 68 years), 292 detemir (66 years), and 874 NPH (65 years) users from 918 practices were retrospectively analyzed (Disease Analyzer, Germany: 2008-2012). The ICT group incorporated 866 glargine (64 years), 512 detemir (60 years), and 1794 NPH (64 years) new users. Persistence was defined as proportion of patients remaining on the initial basal insulin (glargine, detemir and NPH insulin) over 2 years. Persistence was evaluated by Kaplan-Meier curves (log-rank tests) and Cox regression adjusting for age, sex, diabetes duration, antidiabetic co-therapy, comorbidities, specialist care, and private health insurance.

RESULTS

In BOT, two-year persistence was 65%, 53%, and 59% in glargine, detemir, and NPH users, respectively (p<0.001). In ICT, persistence was higher without differences between groups: 84%, 85%, 86% in glargine, detemir, and NPH, respectively (p=0.536). In BOT, detemir and NPH users were more likely to discontinue basal insulin compared with glargine (detemir vs. glargine: adjusted Hazard Ratio; 95% CI: 1.56; 1.31-1.87; NPH vs. glargine: 1.22; 1.07-1.38). Heart failure (1.39; 1.16-1.67) was another predictor of non-persistence, whereas higher age (per year: 0.99; 0.98-0.99), metformin (0.61; 0.54-0.69), and sulfonylurea co-medication (0.86; 0.77-0.97) were associated with lower discontinuation.

CONCLUSIONS

In BOT, treatment persistence among type 2 diabetes patients initiating basal insulin is influenced by type of insulin, antidiabetic co-medication, and patient characteristics.

Mechanical circulatory support improves diabetic control in patients with advanced heart failure

AIMS

Left ventricular assist devices (LVADs) are increasingly being used as life-saving therapy for end-stage advanced heart failure. Diabetes is prevalent in advanced heart failure patients. In this study, we sought to investigate the effects of mechanical circulatory support on diabetic parameters with LVAD implantation.

METHODS AND RESULTS

In this retrospective study, data on 244 LVAD recipients between 2006 and 2013 were reviewed. Patients without history of diabetes, death within the first 3 months after LVAD implantation, heart transplantation after LVAD, or LVAD explantation were excluded from the study. Baseline demographic, laboratory, and echocardiographic information prior to LVAD placement and 6-month follow-up were obtained. Laboratory values indicative of diabetic control were found to improve significantly at 6 months post-LVAD implantation (glycated haemoglobin, 7.2 vs. 6.1%, P < 0.0001; serum fasting glucose, 141 vs. 122 mg/dL, P = 0.003; mean daily insulin dose, 30 vs. 24 IU/day, P = 0.02). Additionally, the use of oral hypoglycaemic medication was successfully discontinued in six patients at 6 months post-LVAD implantation.

CONCLUSIONS

Long-term LVAD therapy is associated with improvement in diabetic control which is probabvly due to improvements in cardiac output and normalization of biochemical derangements resulting from diabetes.

Heart failure as a risk factor for diabetes mellitus

BACKGROUND

Diabetes mellitus (DM) is a well-recognized risk factor for heart failure (HF). We hypothesized that HF also increases the risk for DM.

OBJECTIVE

We explored the hypothesis that HF is a risk factor for DM.

METHODS

The Cardiovascular Health Study was a prospective cohort study of cardiovascular risk in ambulatory older adults. We used a limited-access dataset provided by the National Heart, Lung and Blood Institute. The impact of HF at baseline on DM after 3 or 4 years was examined in a cohort of 3,748 nondiabetic participants aged ≥65 years. The magnitude and significance of the association were evaluated using logistic regression models. Analyses were performed with and without adjustment for confounders and separately among subjects with normal and impaired fasting glucose at baseline.

RESULTS

Among subjects with normal fasting glucose at baseline, HF significantly increased the odds of developing impaired fasting glucose after 3 or 4 years [odds ratio (OR) 2.18, 95% confidence interval (CI) 1.03-4.61, p = 0.043] or overt DM (OR 4.78, 95% CI 1.84-12.4, p < 0.001). After adjusting for demographic and biomedical factors, HF remained significantly associated with a worsening DM status (OR 2.43, 95% CI 1.38-4.29, p = 0.002).

CONCLUSIONS

In the elderly population, the presence of HF more than doubles the incidence of DM within a few years. This association remains significant when adjusting for age, gender and cardiovascular comorbidities.

Impact of left ventricular assist device on diabetes management: an evaluation through case analysis and clinical impact

BACKGROUND

Diabetes is a major risk factor for the development of heart failure (HF). In patients with advanced HF, left ventricular assist devices (LVADs) are increasingly used as a bridge to heart transplantation and destination therapy. It has been our observation that, post-LVAD implantation, diabetes management improves dramatically.

OBJECTIVE

We evaluated insulin requirements in a group of type 2 diabetes patients after LVAD implantation, compared them to a small control group, and performed a pertinent literature review.

METHODS

Relevant clinical and biochemical data were collected by chart review of 11 patients with known type 2 diabetes mellitus and HF who underwent LVAD implantation. Patients treated only with insulin were evaluated and compared with 5 control patients undergoing other cardiac procedures.

RESULTS

Insulin requirement decreased by 73% at 6 months from the pre-LVAD dose despite no significant changes in weight or glomerular filtration rate. Mean hemoglobin A1c reduced post-LVAD to 6.4% from 8.6%. Patients undergoing other cardiac procedures showed no significant changes in hemoglobin A1c or insulin requirements.

CONCLUSION

Patients with diabetes undergoing LVAD implantation demonstrated a significant reduction in insulin requirements. This finding underscores the importance of HF in the progression of insulin resistance.

Animal models of insulin resistance and heart failure

The incidence of heart failure (HF) and diabetes mellitus is rapidly increasing and is associated with poor prognosis. In spite of the advances in therapy, HF remains a major health problem with high morbidity and mortality. When HF and diabetes coexist, clinical outcomes are significantly worse. The relationship between these two conditions has been studied in various experimental models. However, the mechanisms for this interrelationship are complex, incompletely understood, and have become a matter of considerable clinical and research interest. There are only few animal models that manifest both HF and diabetes. However, the translation of results from these models to human disease is limited, and new models are needed to expand our current understanding of this clinical interaction. In this review, we discuss mechanisms of insulin signaling and insulin resistance, the clinical association between insulin resistance and HF, and its proposed pathophysiologic mechanisms. Finally, we discuss available animal models of insulin resistance and HF and propose requirements for future new models.

Association of heart failure severity with risk of diabetes: a Danish nationwide cohort study

AIMS/HYPOTHESIS

Heart failure has been suggested to increase the risk of developing diabetes. We investigated the relation between heart failure severity, defined by loop-diuretic dosage, and the risk of developing diabetes in a nationwide cohort of patients with heart failure.

METHODS

We followed all Danish patients discharged from hospitalisation for first-time heart failure in 1997-2010, without prior use of hypoglycaemic agents, until a claimed prescription for hypoglycaemic agents, death or 31 December 2010. The association of loop-diuretic dosage (furosemide equivalents) 90 days after discharge (study baseline) with risk of diabetes was estimated by multivariate Cox regression models.

RESULTS

In total, 99,362 patients were included and divided into five loop-diuretic dose groups: 30,838 (31%) used no loop diuretics; 24,389 (25%) used >0-40 mg/day; 17,355 (17%) used >40-80 mg/day; 11,973 (12%) used >80-159 mg/day; and 14,807 (15%) used ≥160 mg/day. A total of 7,958 patients (8%) developed diabetes. Loop-diuretic dosages were associated with an increased risk of developing diabetes in a dose-dependent manner. Concomitant use of renin-angiotensin system inhibitors (RASis) attenuated the risk (p value for interaction <0.0001). Compared with patients using no loop diuretics (group 1), the adjusted HRs (95% CI) for developing diabetes for groups 2-5 respectively were 1.16 (1.07, 1.26), 1.35 (1.24, 1.46), 1.48 (1.35, 1.62) and 1.76 (1.61, 1.92) with RASi treatment, and 2.06 (1.83, 2.32), 2.28 (2.01, 2.59), 2.88 (2.52, 3.30) and 3.02 (2.66, 3.43) without RASi treatment.

CONCLUSIONS/INTERPRETATION

In a nationwide cohort of patients with heart failure, severity of heart failure was associated with a stepwise increased risk of developing diabetes. Increased awareness of risk of diabetes associated with severe heart failure is warranted.

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>