Long-term outcome in diabetic heart failure patients treated with cardiac resynchronization therapy

Background: Diabetes mellitus is an independent risk factor for increased morbidity and mortality in heart failure (HF) patients. Aims: To compare functional and structural improvement, as well as long-term outcome, between diabetic and non-diabetic HF patients treated with cardiac resynchronization therapy (CRT). Methods: We compared response to CRT in 141 diabetic and 214 non-diabetic consecutive patients. Major events were; death from any cause, urgent heart transplantation and implantation of a left ventricular (LV) assist device. Frequencies of hospitalisation and defibrillator (CRT-D) discharges were also analyzed. Results: CRT was able to significantly improve functional capacity, ventricular geometry and neurohumoral imbalance in both diabetic and non-diabetic patients over a median follow-up time of 34 months. Overall event-free survival was similar in diabetic and non-diabetic patients (HR 1.23, p = 0.363), as was survival free from CRT-D interventions (HR 1.72; p = 0.115) and hospitalisations (HR 1.12; p = 0.500). On multivariable analysis, NYHA class IV (p = 0.002), low LV ejection fraction (p = 0.002), absence of beta-blocker therapy (p <0.001), impaired renal function (p = 0.003), presence of an epicardial lead (p = 0.025), but not diabetes (p = 0.821) were associated with a poor outcome after CRT. Conclusions: Diabetic HF patients treated with CRT had a very favourable functional and survival outcome, which was comparable to non-diabetic patients.