Best subsets logistic regression analysis was used to identify factors associated with S-LVRR ( defined as 15 % reduction in left ventricular end-systolic volume at 1-year of follow-up ) among 612 patients treated with internal cardioverter defibrillator-only therapy in Multicenter Automatic Defibrillator Implantation Trial-Cardiac Resynchronization Therapy ( MADIT-CRT ) and to create a score for the prediction of S-LVRR .