Objective: To observe the incidence and explore the potential factors of nonresponse to cardiac resynchronization therapy(CRT)in patients with severe chronic congestive heart failure.
Method: CRT was performed in 119 patients with NYHA function class III-IV and left ventricular ejection fraction ≤ 35% [96 men and 23 women, age (60.5 ± 11.3) years].
Results: Seven patients died for different reasons between 1 - 6 months post CRT and clinical and echocardiographic (Echo) data at 6 months post CRT were analyzed from the remaining 112 patients. The incidence of nonresponse to CRT was 28.57%. Compared to the response group, complete right bundle branch block, longer course of congestive heart failure, higher pulmonary systolic pressure and serum creatinine level and non-optimal target vessels positioning of the left ventricle lead (the great cardiac vein and the middle cardiac vein) were the independent predictors for nonresponse after CRT (all P < 0.05). Compared with nonresponse group, the dosages of digoxin and diuretics used for heart failure were significantly reduced in response group (P < 0.01).
Conclusions: The incidence of nonresponse after CRT was 28.57% in this patient cohort. Higher pulmonary systolic pressure and serum creatinine level and non-optimal target vessels positioning of the left ventricle lead (the great cardiac vein and the middle cardiac vein) were the independent predictors for nonresponse after CRT.