Abstract 11639: Effect of Diabetes Mellitus on Clinical Phenotype and Cardiovascular Mortality in Non-Ischaemic Dilated Cardiomyopathy

Abstract

Introduction: Diabetes mellitus (DM) is common amongst patients with heart failure (HF) and associated with adverse outcomes. Historically this has been attributed to the association with atherosclerotic disease. We assessed the effect of DM on phenotype and outcomes in patients with non-ischaemic dilated cardiomyopathy (DCM). Methods: Prospective observational cohort study of 727 patients with DCM. All underwent a cardiac MRI and long-term follow up. The primary endpoint was CV death. Results: Of 727 patients with DCM (472 men, mean age 55 years, median LVEF 40%), 88 (12.1%) had DM at enrolment, of whom 19 (21.6%) were managed with insulin, 52 (59.0%) with oral hypoglycaemic agents (OHA) alone and 17 (19.3%) by diet alone. Enrolment predated guideline recommendations for SGLT2 inhibitors for HF. Patients with DM were older, had higher BMI, higher NYHA class, more were hypertensive and treated with loop diuretics (all p<0.001), ACEi/ARB (p=0.02) and mineralocorticoid receptor antagonists (p=0.002). Compared to patients without DM, those with DM had lower LVEF (mean difference -4% [95%CI -7 to -1], p=0.007) and more had myocardial fibrosis (OR 1.81 [1.13 to 2.91] adjusted for age and sex). After median follow up 7.7 years, 71 patients died from CV causes. DM was associated with higher cumulative incidence of CV death on univariate analysis (log rank p<0.001, Figure), but not after adjusting for age, sex, LVEF, NYHA, fibrosis, LAVi and RVEF (HR 1.66, 0.91 to 3.02, p=0.10). Patients with DM treated with insulin or OHA were at greater risk of CV death even after adjusting for the above variables (HR 2.02, 1.11 to 3.67, p=0.04). DM managed by diet alone was not associated with excess risk. Conclusions: DM is associated with adverse LV remodelling and fibrosis in patients with DCM; the subset requiring OHA or insulin had worse CV prognosis. Risk factor and lifestyle management may improve outcomes. Further studies are needed to assess whether added risk is attenuated by SGLT2 inhibitors.