Objective: To evaluate the incidence of super-response and the potential predictors related to super-response after cardiac resynchronization therapy (CRT) in patients with congestive heart failure.
Methods: 190 patients [145 men and 45 women;age: (60.48 ± 11.91) years] underwent CRT between March 2001 and March 2012 were enrolled in this multi-center trial, of which, 54 patients with ischemic cardiomyopathy and 136 patients with non-ischemic cardiomyopathy. These patients were followed up from 6 months to 11 years (mean 58 months) post CRT.
Results: Ten patients died within 6 months post CRT, the others were followed up for more than 6 months. At 6-month follow-up, 51 patients were identified as CRT super-responders (28.33%), 75 patients were CRT responders (41.67%) and 29 patients were CRT non-responders (16.11%), and 25 patients were CRT negative responders (13.89%). Super-response occurred more frequently in non-ischemic cardiomyopathy patients, while non-response most commonly occurred in ischemic cardiomyopathy patients (P < 0.05); patients in the negative response group had higher serum creatinine level than other groups (P < 0.05) , and patients in the non-response group and negative response group had higher pulmonary artery pressure than patients in the super-response group (P < 0.05); the average QRS duration was ≥ 160 ms before CRT, and the mean decrease was around 30 ms after CRT in the super-response group while the average QRS duration was 139 ms before CRT, and the mean reduction was around 8 ms after CRT in the negative response group (P < 0.05). LV lead position in the super-response group was usually in the middle and base of the heart, while in the negative response group it was more commonly located in the apex of the heart (P < 0.01) .
Conclusions: LV lead located at the middle and pre-CRT ORS duration ≥ 160 ms are associated with super-response post CRT procedure in this patient cohort.