Identification of 'super-responders' to cardiac resynchronization therapy: the importance of symptom duration and left ventricular geometry

AIMS: Some patients show such an important clinical improvement and reverse remodelling after cardiac resynchronization therapy (CRT) that anatomy and function approach normal. These patients have been called 'super-responders'. The aim of our study was to identify predictors of becoming a super-responder after CRT. METHODS AND RESULTS: Eighty-seven consecutive patients who underwent CRT were prospectively studied. Before CRT and 6 months after, clinical and echocardiographic evaluation was performed. Patients with a decrease in New York Heart Association functional class >or=1, a two-fold or more increase of left ventricular ejection fraction (LVEF) or a final LVEF >45%, and a decrease in LV end-systolic volume >15% were classified as super-responders. There were 12% super-responders. At baseline, there were no significant differences between super-responders and the other patients, except for the fact that super-responders had significantly smaller mitral regurgitation and LV end-diastolic diameter (LVEDD) and a shorter duration of heart failure symptoms. Mitral regurgitation jet area, LVEDD, and duration of heart failure symptoms were correlated with this super-response. Moreover, an evolution of symptoms for <12 months was an independent predictor of super-response to CRT. CONCLUSION: Patients in earlier phases of the cardiomyopathy, with a less altered ventricular geometry, seem to have a greater probability of becoming super-responders.