[Cardiac resynchronization therapy and reduction of mortality in heart failure: a proven association]

Cardiac resynchronization therapy (CRT) is currently used for treatment of refractory heart failure and is effective in reducing symptoms and increasing quality of life and exercise tolerance. Data from the literature also show that CRT may prolong event-free survival and reduce heart failure mortality. This therapy is also highly cost-effective as compared to optimized medical treatment. The reduction of the risk of death occurs in both nonischemic and ischemic heart failure, although in this latter group CRT benefit seems to be less. It is still controversial whether a back-up defibrillator should be implanted to all patients undergoing CRT. Finally, left ventricular reverse remodeling occurring after 3 to 6 months of treatment predicts long-term benefit of CRT on mortality.