Prognostic impact of diabetes mellitus in chronic heart failure according to presence of ischemic heart disease-with special reference to nephropathy

Background: It is unclear whether the prognostic impact of diabetes mellitus (DM) in chronic heart failure (CHF) is influenced by ischemic heart disease (IHD) and/or nephropathy. Methods and Results: We enrolled 4,065 consecutive patients with stage C/D CHF (mean age, 69.0 years; 68.7% male) in the CHART-2 Study (n=10,219). We defined DM as current history of DM treatment or HbA1c ≥6.5% (National Glycohemoglobin Standardization Program [NGSP]), and nephropathy as urine albumin:creatinine ratio ≥30 mg/g or urine dipstick test ≥(}) at enrollment. Impacts of DM and nephropathy on the composite of death, myocardial infarction, stroke, and HF admission were examined. Among the 4,065 patients, 1,448 (35.6%) had DM, while IHD and nephropathy were also noted in 1,644 (40.4%) and in 1,549 (38.1%), respectively. During the median followup of 2.88 years, 1,025 (25.2%) reached the composite endpoint. On multivariate Cox regression, DM was significantly associated with the composite endpoint in all patients (HR, 1.17; P=0.02), and in those with IHD (HR, 1.38; P=0.004), but not in those without IHD (HR, 1.12; P=0.22; P for interaction=0.12). Furthermore, when the patients were stratified by nephropathy, DM was associated with worse prognosis only in the IHD patients with nephropathy. Conclusions: The prognostic impact of DM was more evident in patients with IHD than in those without IHD, particularly when complicated with nephropathy.