Evidence for a Specific Diabetic Cardiomyopathy: An Observational Retrospective Echocardiographic Study in 656 Asymptomatic Type 2 Diabetic Patients

Randomized Trial of a Selective Aldose Reductase Inhibitor in Patients With Diabetic Cardiomyopathy

BACKGROUND

Progression to symptomatic heart failure is a complication of type 2 diabetes; heart failure onset in this setting is commonly preceded by deterioration in exercise capacity.

OBJECTIVES

This study sought to determine whether AT-001, a highly selective aldose reductase inhibitor, can stabilize exercise capacity among individuals with diabetic cardiomyopathy (DbCM) and reduced peak oxygen uptake (Vo2).

METHODS

A total of 691 individuals with DbCM meeting inclusion and exclusion criteria were randomized to receive placebo or ascending doses of AT-001 twice daily. Stratification at inclusion included region of enrollment, cardiopulmonary exercise test results, and use of sodium-glucose cotransporter 2 inhibitors or glucagon-like peptide-1 receptor agonists. The primary endpoint was proportional change in peak Vo2 from baseline to 15 months. Subgroup analyses included measures of disease severity and stratification variables.

RESULTS

The mean age was 67.5 ± 7.2 years, and 50.4% of participants were women. By 15 months, peak Vo2 fell in the placebo-treated patients by -0.31 mL/kg/min (P = 0.005 compared to baseline), whereas in those receiving high-dose AT-001, peak Vo2 fell by -0.01 mL/kg/min (P = 0.21); the difference in peak Vo2 between placebo and high-dose AT-001 was 0.30 (P = 0.19). In prespecified subgroup analyses among those not receiving sodium-glucose cotransporter 2 inhibitors or glucagon-like peptide-1 receptor agonists at baseline, the difference between peak Vo2 in placebo vs high-dose AT-001 at 15 months was 0.62 mL/kg/min (P = 0.04; interaction P = 0.10).

CONCLUSIONS

Among individuals with DbCM and impaired exercise capacity, treatment with AT-001 for 15 months did not result in significantly better exercise capacity compared with placebo. (Safety and Efficacy of AT-001 in Patients With Diabetic Cardiomyopathy [ARISE-HF]; NCT04083339).

Diabetic myocardial disorder. A clinical consensus statement of the Heart Failure Association of the ESC and the ESC Working Group on Myocardial & Pericardial Diseases

The association between type 2 diabetes mellitus (T2DM) and heart failure (HF) has been firmly established; however, the entity of diabetic myocardial disorder (previously called diabetic cardiomyopathy) remains a matter of debate. Diabetic myocardial disorder was originally described as the occurrence of myocardial structural/functional abnormalities associated with T2DM in the absence of coronary heart disease, hypertension and/or obesity. However, supporting evidence has been derived from experimental and small clinical studies. Only a minority of T2DM patients are recognized as having this condition in the absence of contributing factors, thereby limiting its clinical utility. Therefore, this concept is increasingly being viewed along the evolving HF trajectory, where patients with T2DM and asymptomatic structural/functional cardiac abnormalities could be considered as having pre-HF. The importance of recognizing this stage has gained interest due to the potential for current treatments to halt or delay the progression to overt HF in some patients. This document is an expert consensus statement of the Heart Failure Association of the ESC and the ESC Working Group on Myocardial & Pericardial Diseases. It summarizes contemporary understanding of the association between T2DM and HF and discuses current knowledge and uncertainties about diabetic myocardial disorder that deserve future research. It also proposes a new definition, whereby diabetic myocardial disorder is defined as systolic and/or diastolic myocardial dysfunction in the presence of diabetes. Diabetes is rarely exclusively responsible for myocardial dysfunction, but usually acts in association with obesity, arterial hypertension, chronic kidney disease and/or coronary artery disease, causing additive myocardial impairment.

Impact of oxidative stress on myocardial performance in patients with diabetes: a focus on subclinical left ventricular dysfunction

INTRODUCTION

Oxidative stress is known to affect left ventricular functions negatively. There is a strong bidirectional connection between diabetes mellitus (DM) and oxidative stress. In parallel, left ventricular dysfunction is observed more frequently, even in patients with DM without other risk factors. In this context, the objective of this study is to comparatively investigate the potential relationship between oxidative stress and subclinical left ventricular dysfunction (SCLVD) assessed by Myocardial Performance Index (MPI) in patients with and without DM.

RESEARCH DESIGN AND METHODS

The sample of this observational cross-sectional single-center study consisted of 151 patients who were evaluated for oxidative stress and SCLVD by tissue Doppler echocardiography. Patients' total oxidant status (TOS), total antioxidant status (TAS), and Oxidative Stress Index (OSI) values were calculated. The effects of oxidative stress and DM on MPI were analyzed.

RESULTS

There were 81 patients with DM (mean age: 46.17±10.33 years) and 70 healthy individuals (mean age: 45.72±9.04 years). Mean TOS and OSI values of the DM group were higher than healthy individuals (5.72±0.55 vs 5.31±0.50, p = <0.001; and 4.92±1.93 vs 1.79±0.39, p = <0.001; respectively). The mean TAS value of the DM group was significantly lower than the healthy group (1.21±0.40 vs 3.23±0.51, p = <0.001). There was a significant correlation between OSI and MPI mitral in the DM group (R 0.554, p = <0.001) but not in the healthy group (R -0.069, p=0.249).

CONCLUSIONS

Both oxidative stress and myocardial dysfunction were found to be more common in patients with DM. The study's findings indicated the negative effect of oxidative stress on myocardial functions. Accordingly, increased oxidative stress caused more significant deterioration in MPI in patients with DM compared with healthy individuals.

Prevalence of diabetic cardiomyopathy in patients with type 2 diabetes in a large academic medical center

BACKGROUND

Diabetic cardiomyopathy (DbCM) is characterized by asymptomatic stage B heart failure (SBHF) caused by diabetes-related metabolic alterations. DbCM is associated with an increased risk of progression to overt heart failure (HF). The prevalence of DbCM in patients with type 2 diabetes (T2D) is not well established. This study aims to determine prevalence of DbCM in adult T2D patients in real-world clinical practice.

METHODS

Retrospective multi-step review of electronic medical records of patients with the diagnosis of T2D who had echocardiogram at UC San Diego Medical Center (UCSD) within 2010-2019 was conducted to identify T2D patients with SBHF. We defined "pure" DbCM when SBHF is associated solely with T2D and "mixed" SBHF when other medical conditions can contribute to SBHF. "Pure" DbCM was diagnosed in T2D patients with echocardiographic demonstration of SBHF defined as left atrial (LA) enlargement (LAE), as evidenced by LA volume index ≥ 34 mL/m2, in the presence of left ventricular ejection fraction (LVEF) ≥ 45%, while excluding overt HF and comorbidities that can contribute to SBHF.

RESULTS

Of 778,314 UCSD patients in 2010-2019, 45,600 (5.9%) had T2D diagnosis. In this group, 15,182 T2D patients (33.3%) had echocardiogram and, among them, 13,680 (90.1%) had LVEF ≥ 45%. Out of 13,680 patients, 4,790 patients had LAE. Of them, 1,070 patients were excluded due to incomplete data and/or a lack of confirmed T2D according to the American Diabetes Association recommendations. Thus, 3,720 T2D patients with LVEF ≥ 45% and LAE were identified, regardless of HF symptoms. In this group, 1,604 patients (43.1%) had overt HF and were excluded. Thus, 2,116 T2D patients (56.9% of T2D patients with LVEF ≥ 45% and LAE) with asymptomatic SBHF were identified. Out of them, 1,773 patients (83.8%) were diagnosed with "mixed" SBHF due to comorbidities such as hypertension (58%), coronary artery disease (36%), and valvular heart disease (17%). Finally, 343 patients met the diagnostic criteria of "pure" DbCM, which represents 16.2% of T2D patients with SBHF, i.e., at least 2.9% of the entire T2D population in this study.

CONCLUSIONS

Our findings provide insights into prevalence of DbCM in real-world clinical practice and indicate that DbCM affects a significant portion of T2D patients.

Rationale and design of the Aldose Reductase Inhibition for Stabilization of Exercise Capacity in Heart Failure Trial (ARISE-HF) in patients with high-risk diabetic cardiomyopathy

BACKGROUND

Diabetic cardiomyopathy (DbCM) is a specific form of heart muscle disease that may result in substantial morbidity and mortality in individuals with type 2 diabetes mellitus (T2DM). Hyperactivation of the polyol pathway is one of the primary mechanisms in the pathogenesis of diabetic complications, including development of DbCM. There is an unmet need for therapies targeting the underlying metabolic abnormalities that drive this form of Stage B heart failure (HF).

METHODS

Aldose reductase (AR) catalyzes the first and rate-limiting step in the polyol pathway, and AR inhibition has been shown to reduce diabetic complications, including DbCM in animal models and in patients with DbCM. Previous AR inhibitors (ARIs) were limited by poor specificity resulting in unacceptable tolerability and safety profile. AT-001 is a novel investigational highly specific ARI with higher binding affinity and greater selectivity than previously studied ARIs. ARISE-HF (NCT04083339) is an ongoing Phase 3 randomized, placebo-controlled, double blind, global clinical study to investigate the efficacy of AT-001 (1000 mg twice daily [BID] and 1500 mg BID) in 675 T2DM patients with DbCM at high risk of progression to overt HF. ARISE-HF assesses the ability of AT-001 to improve or prevent decline in exercise capacity as measured by functional capacity (changes in peak oxygen uptake [peak VO₂]) over 15 (and possibly 27) months of treatment. Additional endpoints include percentage of patients progressing to overt HF, health status metrics, echocardiographic measurements, and changes in cardiacbiomarkers.

RESULTS

The ARISE-HF Trial is fully enrolled.

CONCLUSIONS

This report describes the rationale and study design of ARISE-HF.

Association of continuous positive airway pressure therapy on cardiac hypertrophy in patients with sleep apnea comorbid with type 2 diabetes mellitus

Previous reports indicated the therapeutic effect of chronic continuous positive airway pressure (CPAP) therapy on cardiac hypertrophy due to sleep apnea syndrome. However, little is known for cases involving diabetic complications. This retrospective observational study examined the effects of CPAP therapy on left ventricular hypertrophy (LVH) in patients with obstructive sleep apnea syndrome (OSAS) and type 2 diabetes mellitus (T2DM). For all cases, the observation period was 3 years from the time when the patient was introduced to CPAP therapy. Overall, 123 patients were divided into a good CPAP group (CPAP ≥4 h/day, n = 63) and non-adherence group (CPAP <4 h/day, n = 60). The mean CPAP usage times were 5.58 ± 1.23 and 1.03 ± 1.17 h/day in the good CPAP and non-adherence groups, respectively. Regression tendencies of the thickness of the left ventricular posterior (-0.30 ± 1.19 mm) and interventricular septal walls (-0.48 ± 1.22 mm) were observed in the good CPAP group. Hypertrophic tendencies of the left ventricular posterior wall (+0.59 ± 1.44 mm) and interventricular septal wall thickness (+0.59 ± 1.43) were observed in the non-adherence group. Left ventricular posterior wall thickness (coefficient: -0.254, p = 0.0376) and interventricular septal wall thickness (coefficient: -0.426, p = 0.0006) were more likely to be greater in the non-adherence group than in the good CPAP group. Patients in the non-adherence group with an apnea hypopnea index ≥30 had increased left ventricular posterior wall thickness (coefficient: -0.263, p = 0.0673) and interventricular septal wall thickness (coefficient: -0.450, p = 0.0011). In conclusion, appropriate CPAP therapy is an effective treatment for LVH in patients with T2DM and OSAS, especially for severe cases.

Diabetic cardiomyopathy: a brief summary on lipid toxicity

Diabetes mellitus (DM) is a serious epidemic around the globe, and cardiovascular diseases account for the majority of deaths in patients with DM. Diabetic cardiomyopathy (DCM) is defined as a cardiac dysfunction derived from DM without the presence of coronary artery diseases and hypertension. Patients with either type 1 or type 2 DM are at high risk of developing DCM and even heart failure. Metabolic disorders of obesity and insulin resistance in type 2 diabetic environments result in dyslipidaemia and subsequent lipid-induced toxicity (lipotoxicity) in organs including the heart. Although various mechanisms have been proposed underlying DCM, it remains incompletely understood how lipotoxicity alters cardiac function and how DM induces clinical heart syndrome. With recent progress, we here summarize the latest discoveries on lipid-induced cardiac toxicity in diabetic hearts and discuss the underlying therapies and controversies in clinical DCM.

Heart failure in type 2 diabetes: current perspectives on screening, diagnosis and management

Type 2 diabetes is one of the most relevant risk factors for heart failure, the prevalence of which is increasing worldwide. The aim of the review is to highlight the current perspectives of the pathophysiology of heart failure as it pertains to type 2 diabetes. This review summarizes the proposed mechanistic bases, explaining the myocardial damage induced by diabetes-related stressors and other risk factors, i.e., cardiomyopathy in type 2 diabetes. We highlight the complex pathology of individuals with type 2 diabetes, including the relationship with chronic kidney disease, metabolic alterations, and heart failure. We also discuss the current criteria used for heart failure diagnosis and the gold standard screening tools for individuals with type 2 diabetes. Currently approved pharmacological therapies with primary use in type 2 diabetes and heart failure, and the treatment-guiding role of NT-proBNP are also presented. Finally, the influence of the presence of type 2 diabetes as well as heart failure on COVID-19 severity is briefly discussed.

Correlation between albuminuria and tissue Doppler-derived left ventricular myocardial performance index in patients with type 2 diabetes

BACKGROUND

Albuminuria is considered as a significant predictor of cardiovascular morbidity and mortality in patients with diabetes mellitus. The main purpose of this study was to determine the correlation between albuminuria and global left ventricular (LV) function in patients with type 2 diabetes (T2D).

METHODS

This observational study was conducted on 80 consecutive asymptomatic patients with T2D and an LV ejection fraction ≥55%. The patients were divided into two groups depending on the presence or absence of albuminuria. Echocardiography-derived indices of the LV function were then compared between these groups.

RESULTS

The patients with albuminuria were older (mean ± SD: 60.37 ± 9.05 vs 54.52 ± 10.26 years of age, P = .01) and had higher hemoglobin A1c (HbA1c) levels (8.45 ± 1.97 vs 7.25 ± 1.93 mg/dL, P = .012) than those without albuminuria. Among the echocardiographic variables, the patients with albuminuria had higher LV Tei-index (median [lower-upper quartile]: 0.620 [0.455-0.824] vs 0.441 [0.336-0.586], P < .001), more prolonged early filling (E)-wave deceleration time (274.87 ± 75.97 vs 239.40 ± 61.35 ms, P = .032), increased interventricular septal wall thickness (1.11 ± 0.31 vs 0.95 ± 0.21 cm, P = .012), and lower mean early diastolic mitral annular velocity (7.57 ± 2.34 vs 8.68 ± 2.46 cm/s, P = .046) than those without albuminuria. Among risk factors, only albuminuria and HbA1c levels were associated with a significant increase in LV Tei-index (Beta = 0.426 and P < .001, Beta = 0.226 and P = .042, respectively).

CONCLUSION

The LV Tei-index was significantly higher in diabetic patients with than without albuminuria. Low HbA1c levels were correlated with a decrease in LV Tei-index.

The impact of diabetes on heart failure development: The cardio-renal-metabolic connection

Heart failure (HF) and chronic kidney disease (CKD) are often associated in type 2 diabetes (T2D), aggravate each other and exert synergistic effects to increase the risk of cardiac and renal events. The risks of renal worsening in HF patients and HF in CKD patients need to be evaluated to tailor preventive therapy. The recent CV and renal trials enriched our knowledge about the natural history of HF and CKD in T2D and provided evidence for the benefit of sodium-glucose cotransporter 2 inhibitors (SGLT2is) in HF and renal decline prevention. SGLT-2is are the best choice in patients with HFrEF to improve CV prognosis and HF-related outcomes and also to prevent kidney-related outcomes, and in CKD patients to slow down renal failure and also reduce hospitalization for HF and CV death. In both situations the number of patients to treat in order to prevent such events in one patient is lower than in the general T2D population at high CV risk. GLP1-receptor agonists could be an alternative in a patient who is intolerant or has a contraindication to SGLT-2is. A tight collaboration between diabetologists, nephrologists and cardiologists should be encouraged for a holistic and effective strategy to reduce the burden of cardio-renal-metabolic interaction.

Burden of disease and costs associated with type 2 diabetes in emerging and established markets: systematic review analyses

Objectives: To estimate the clinical and economic burden of type 2 diabetes (T2D) in established (EST) and emerging markets (EMG).Methods: Three systematic literature reviews were conducted in MEDLINE and Embase to capture all relevant publications reporting 1) the epidemiology of T2D and complications in T2D and 2) the economic burden of T2D and associated complications.Results: In total, 294 studies were included in this analysis. Evidence indicates a high and increasing overall prevalence of T2D globally, ranging up to 23% in EMG markets and 14% in EST markets. Undiagnosed cases were higher in EMG versus EST markets (up to 67% vs 38%), potentially due to a lack of education and disease awareness in certain regions, that could lead to important clinical and economic consequences. Poor glycemic control was associated with the development of several complications (e.g. retinopathy, cardiovascular diseases and nephropathy) that increase the risk of morbidity and mortality. Direct costs were up to 9-fold higher in patients with vs without T2D-related complications.Conclusions: The burden of T2D, related complications and inherent costs are higher in emerging versus established market countries. This review explores potential strategies to reduce costs and enhance outcomes of T2D treatment in developing countries.

Mechanisms underlying diabetic cardiomyopathy: From pathophysiology to novel therapeutic targets

Diabetic cardiomyopathy (DC) is defined as a clinical condition of cardiac dysfunction that occurs in the absence of coronary atherosclerosis, valvular disease, and hypertension in patients with diabetes mellitus (DM). Despite the increasing worldwide prevalence of DC, due to the global epidemic of DM, the underlying pathophysiology of DC has not been fully elucidated. In addition, the clinical criteria for diagnosing DC have not been established, and specific therapeutic options are not currently available. The current paradigm suggests the impaired cardiomyocyte function arises due to a number of DM-related metabolic disturbances including hyperglycemia, hyperinsulinemia, and hyperlipidemia, which lead to diastolic dysfunction and signs and symptoms of heart failure. Other factors, which have been implicated in the progression of DC, include mitochondrial dysfunction, increased oxidative stress, impaired calcium handling, inflammation, and cardiomyocyte apoptosis. Herein, we review the current theories surrounding the occurrence and progression of DC, and discuss the recent advances in diagnostic methodologies and therapeutic strategies. Moreover, apart from conventional animal DC models, we highlight alternative disease models for studying DC such as the use of patient-derived human induced pluripotent stem cells (hiPSCs) for studying the mechanisms underlying DC. The ability to obtain hiPSC-derived cardiomyocytes from DM patients with a DC phenotype could help identify novel therapeutic targets for preventing and delaying the progression of DC, and for improving clinical outcomes in DM patients.

Association of Urine Albumin/Creatinine Ratio below 30 mg/g and Left Ventricular Hypertrophy in Patients with Type 2 Diabetes

Several studies show that even a level of urine albumin/creatinine ratio (UACR) within the normal range (below 30 mg/g) increases the risk of cardiovascular diseases. We speculate that mildly increased UACR is related to left ventricular hypertrophy (LVH) in patients with type 2 diabetes mellitus (T2DM). In this retrospective study, 317 patients with diabetes with normal UACR, of whom 62 had LVH, were included. The associations between UACR and laboratory indicators, as well as LVH, were examined using multivariate linear regression and logistic regression, respectively. The diagnostic efficiency and the optimal cutoff point of UACR for LVH were evaluated using the area under the receiver operating characteristic curve (AUC) and Youden index. Our results showed that patients with LVH had significantly higher UACR than those without LVH (P < 0.001). The prevalence of LVH presented an upward trend with the elevation of UACR. UACR was independently and positively associated with hemoglobin A1c (P < 0.001). UACR can differentiate LVH (AUC = 0.682, 95% CI (0.602–0.760), P < 0.001). The optimal cutoff point determined with the Youden index was UACR = 10.2 mg/g. When categorized by this cutoff point, the odds ratio (OR) for LVH in patients in the higher UACR group (10.2–30 mg/g) was 3.104 (95% CI: 1.557–6.188, P=0.001) compared with patients in the lower UACR group (<10.2 mg/g). When UACR was analyzed as a continuous variable, every double of increased UACR, the OR for LVH was 1.511 (95% CI: 1.047–2.180, P=0.028). Overall, UACR below 30 mg/g is associated with LVH in patients with T2DM. The optimal cutoff value of UACR for identifying LVH in diabetes is 10 mg/g.

Perioperative management of adult diabetic patients. Preoperative period

In diabetic patients undergoing surgery, we recommend assessing glycaemic control preoperatively by assessing glycated haemoglobin (HbA1c) levels and recent capillary blood sugar (glucose) levels, and to adjust any treatments accordingly before surgery, paying particular attention to specific complications of diabetes. Gastroparesis creates a risk of stasis and aspiration of gastric content at induction of anaesthesia requiring the use of a rapid sequence induction technique. Cardiac involvement can be divided into several types. Coronary disease is characterised by silent myocardial ischaemia, present in 30-50% of T2D patients. Diabetic cardiomyopathy is a real cause of heart failure. Finally, cardiac autonomic neuropathy (CAN), although rarely symptomatic, should be investigated because it causes an increased risk of cardiovascular events and a risk of sudden death. Several signs are suggestive of CAN, and confirmation calls for close perioperative surveillance. Chronic diabetic kidney disease (diabetic nephropathy) aggravates the risk of perioperative acute renal failure, and we recommend measurement of the glomerular filtration rate preoperatively. The final step of the consultation concerns the management of antidiabetic therapy. Preoperative glucose infusion is not necessary if the patient is not receiving insulin. Non-insulin drugs are not administered on the morning of the intervention except for metformin, which is not administered from the evening before. The insulins are injected at the usual dose the evening before. The insulin pump is maintained until the patient arrives in the surgical unit. It should be remembered that insulin deficiency in a T1D patient leads to ketoacidosis within a few hours.