Diabetes associated with significantly increased risk of mortality in cardiomyopathy

Patients with diabetes and mild-to-moderate cardiomyopathy had higher mortality risk than nondiabetic patients with severe cardiomyopathy, suggesting that they may benefit from implantable cardioverter defibrillators, according to the study authors.

Diabetes is a stronger predictor of worse outcomes than severity of cardiomyopathy, a study found.

To examine the independent predictors of all-cause mortality, all hospitalizations, and cardiac hospitalizations, researchers looked at patients with mild-to-moderate cardiomyopathy (left ventricular ejection fraction [LVEF] 36% to 50%) versus patients with severe cardiomyopathy (LVEF ≤35%).The study included consecutive patients seen at the University of Pittsburgh Medical Center from 2011 to 2017, followed from first outpatient presentation to a primary endpoint of all-cause death or secondary endpoints of first hospitalization or first cardiac hospitalization. Results appeared in the February JACC: Clinical Electrophysiology.

Of 18,003 patients with cardiomyopathy, 5,966 (33%) had an LVEF between 36% and 50%. Over a median follow-up of 3.35 years, 8,037 (45%) patients died and 11,056 (61%) were hospitalized for cardiac reasons. Independent predictors of all-cause mortality included older age (P<0.001) and a history of diabetes (P=0.005) or heart failure (P=0.043). A higher baseline hemoglobin level showed a protective effect (hazard ratio [HR], 0.79; 95% CI, 0.71 to 0.89; P<0.001). Patients with diabetes and mild-to-moderate cardiomyopathy had worse survival than those with severe cardiomyopathy and no diabetes (HR, 1.10; 95% CI, 1.02 to 1.19; P=0.010).

The finding needs to be verified in a prospective, randomized setting, the authors wrote, but it could have immediate and profound clinical implications for managing patients with mild-to-moderate myocardial dysfunction.

“Diabetic patients with any degree of cardiomyopathy are at a significantly high risk of poor outcomes. This risk may be mitigated by expanding the indications for life-saving therapies such as the ICD [implantable cardioverter defibrillator] to diabetic patients with mild-to-moderate cardiomyopathy,” they wrote.