Impact of diabetes mellitus on long-term survival in patients with congestive heart failure

Aims To test the hypothesis that diabetic status may be used as a prognostic indicator in heart failure (HF) patients. Methods and results We studied 1246 consecutive patients with left ventricular dysfunction. All patients had a cardiopulmonary exercise test and an echocardiogram. Cardiac catheterisation was systematically performed to define HF aetiology. Twenty-two percent of the patients were diabetic (hypoglycaemic drugs or fasting blood glucose > 126 mg/dL); in diabetic patients, HF aetiology was ischaemic in 58% vs. 40% in non-diabetic patients (p < 0.0001). Clinical follow-up (median 1200 days) was obtained for 1241 patients. There was a statistically significant effect of diabetes mellitus on cardiac survival that differed according to HF aetiology (interaction p < 0.01). Diabetes mellitus was an independent predictor of cardiovascular mortality in ischaemic patients (HR = 1.54 [1.13; 2.09]; p = 0.006) but not in non-ischaemic patients (FIR = 0.65 [0.39; 1.07]; p = 0.09). When diabetic patients were defined as patients receiving hypoglycaemic drugs at baseline, diabetes mellitus remained an independent predictor of cardiovascular mortality in ischaemic patients (HR = 1.43 [1.03; 1.98]; p = 0.03) white diabetes mellitus was associated with a statistically significant decrease in cardiovascular mortality in non-ischaemic patients (HR = 0.46 [0.23; 0.88]; p = 0.02). Conclusion The prognostic impact of diabetes mellitus in HF patients is markedly influenced by the underlying aetiology and is particularly deleterious in those with ischaemic cardiomyopathy. (C) 2004 The European Society of Cardiology. Published by Elsevier Ltd. All rights reserved.