Abstract： Background Chronic heart failure(CHF)and diabetes mellitus portend high morbidity and mortality because of an interrelated pathophysiologic process.This large cohort study aimed to analyze the prevalence,clinicaI characteristics and long-term outcome of patients with CHF and diabetes.Methods A totaI of 1119 patients with NYHA functionaI class Ⅱ-Ⅳ and left ventricular ejection fraction(LVEF)<45% between January 1995 and May 2009 were recruited.Clinical variables, biochemical and echocardiographic measurements were retrospectively reviewed,and composite major cardiac events (MCE) including death,headtransplantation, and refractory heart failure requiring multiple hospitalizations were recorded.Results The prevalence of CHF with diabetes was progressively increased with time (16.9% in 1995-1999;20.4% in 2000-2004,and 29.1% in 2005-2009)and age(1 8.5% in<60 years,26.6% in 60-80 years,and 26.6% in>80 years).Compared with CHF patients without diabetes,those with diabetes had worse cardiac function,more abnormal biochemical changes.and higher mortality.Treatment with glucose-lowering agents significantly improved LVEF and decreased MCE.An elevated serum HbA1c level was associated with large left ventricular end-systolic diameter (P<0.05),decreased LVEF(P<0.01)and reduced survival(P＜0.05).Multivariable Logistic regression analysis revealed that after adjustment for confounding factors,NYHA functional class(OR2.65,95%CI 1.14-6.16,P=0.024)and HbA1c level≥7%(OR2.78, 95%CI 1.00-7.68,P=0.049)were independent risk factors for adverse outcomes in CHF patients with diabetes.Conclusions Prevalence of CHF with diabetes was increasing during past decades,and patients with CHF and diabetes had worse clinical profiles and prognosis.Aggressive anti-CHF and diabetes therapies are needed to improve overall outcomes for these patients.