With David S.H. Bell, MD, Richard E. Gilbert, MD, PhD, and Aaron Vinick, MD, PhD
For people with diabetes, heart failure can no longer be just a cardiologist’s concern.
Endocrinologists must increase their vigilance of heart failure (HF), a highly troublesome complication of diabetes, by intensifying efforts to treat symptomatic patients, according to a panel of specialists during a symposium, Heart Failure: the Frequent, Forgotten and Often Fatal Complication of Type 2 Diabetes,1 at the American Association of Clinical Endocrinologists’ 26th Annual Scientific and Clinical Congress, held May 3-7 in Austin, Texas.1
Much attention has been given to the microvascular effects of type 2 diabetes (T2D), such as diabetic retinopathy, kidney disease, and neuropathy, as well as to the macrovascular consequences including stroke, myocardial infarction, and peripheral vascular disease.1
However, the evidence on heart failure should prompt endocrinologists to be more rigorous in screening their symptomatic patients and treating them to mitigate poor outcomes, said David S.H. Bell, MD, former professor of medicine at the University of Alabama Medical School. Diabetes increases the risk of cardiac dysfunction and heart failure independently of other risk factors such as cardiovascular disease (CVD) and hypertension.2
“It’s not widely recognized how common this condition is, said Dr. Bell, who has performed clinical trials on the effects of angiotensin II receptor blockers in patients with diabetes and diastolic dysfunction, but “it falls somewhere between 40% and 45% of people in the US with diabetes suffer heart failure versus 12% of nondiabetics.” And the mortality increases as the degree of glycemic control declines.
“Antihyperglycemic treatment is essential to controlling diabetes, of course,“ Dr. Bell told EndocrineWeb, ”but diuretics, exercise, controlling atrial fibrillation, and treating sleep apnea are important as well. Revascularization procedures including surgery and stents, if needed, may save lives.”
Dr. Bell highlighted studies that examined the complex effects of diabetes and other contributors to the causes of heart failure.1 These include CVD, left ventricular hypertrophy, which occurs in as many as 65% of those with T2D, and diabetic cardiomyopathy, the changes in the structure and function of the myocardium that are closely associated with the microvascular complications of diabetes.1,3
"Hyperglycemia and the strategies we choose to control it are important factors in heart failure," said Richard E. Gilbert, MD, PhD, chair of the Division of Endocrinology, St. Michael's Hospital, Canada Research Chair in Diabetes Complications, and Professor of Medicine at the University of Toronto, during his presentation.1
Dr. Gilbert, an expert in diabetic kidney disease and heart failure, highlighted the relationship between glycemic control and heart failure risk, contrasting the absence of a significant effect in comparatively short-term studies in T2D with the 30-year follow-up in T1D from the DCCT-EDIC study where intensive glycemic control was beneficial.1
Since 2008, the Food and Drug Administration has mandated that new diabetes medications undergo CVD safety outcome trials in high-risk T2D patients. As a result, a growing body of evidence points to the ability of certain anti-diabetes medications to reduce CVD mortality, overall mortality, and hospitalizations for worsening heart failure in high-risk patients with T2D. 4-7
"Thiazolidinediones, such as rosiglitazone, have been associated with an increased risk of heart failure due to fluid retention," said Dr. Gilbert. "In addition, an increased risk of heart failure with the dipeptidylpeptidase-4 (DPP4) inhibitor, saxagliptin, was seen in the SAVOR-TIMI 53 trial."1,4
In this trial, patients had an unexpectedly higher risk of hospitalization for heart failure, a component of the secondary composite endpoint.5 However, this risk disappeared after the first year of follow-up and a subsequent trial with the DPP4 inhibitor, sitagliptin, observed no increases in heart failure risk,5 according to Dr. Gilbert.
The newest drugs, the sodium-glucose co-transporter 2 (SGLT-2) inhibitors, on the other hand, have recently been shown to reduce the rate of hospitalization for heart failure by 39% compared with placebo.6
“In patients with T2D who require additional treatment after first-line therapy with metformin, adding an SGLT-2 inhibitor may be the best approach to preventing heart failure,” Dr. Gilbert told EndocrineWeb.
“Autonomic system dysfunction is a predictor of cardiovascular risk and sudden death in T2D patients,” according to Aaron Vinik, MD, PhD, Director of the Research and the Neuroendocrine Unit and Murray Waitzer Endowed Chair for Diabetes Research at Eastern Virginia Medical School. Because it also occurs in prediabetes, early intervention is possible.1
Dr. Vinik presented findings from his research on autonomic neuropathy,7 one of the most overlooked complications of T2D that contributes to the high incidence of associated heart failure. The heart failure occurs when damage to the blood vessels extends to the involuntary nerves that stimulate the heart and blood vessels, resulting in heart rate and vascular abnormalities, Dr. Vinik explained.
Important advances in technology are making it possible to identify these early stages of autonomic dysfunction, said Dr. Vinik, allowing earlier intervention when reversal of the condition is still possible.