196 Non response after cardiac resynchronisation therapy is associated with a more severe cardiomyopathy

Abstract

Cardiac resynchronisation therapy (CRT) has been shown to improve clinical status in heart failure patients. Some patients treated by CRT fail to respond to the treatment. Predisposing factors for non-response should be investigated to optimize patient selection. The purpose of the study was to evaluate before device implantation and 3, 6 and 12 month after, echocardiographic and biological parameters with respect to CRT response. Thirty two patients with heart failure (72% of men; age 66 ± 10 years; 59% non-ischaemic cardiomyopathy; NYHA III–IV; left ventricular ejection fraction (LVEF) 22.7 ± 6.7%; QRS width 146 ± 26 ms) were implanted with CRT device and followed during twelve month. Responders (R) were defined as patients with improvement of one or more NYHA functional class, with a significant improvement in quality of life and without episode nor hospitalization for heart failure during follow-up. 34% of the patients constitute the non-responder group (NR). No difference between R and NR was observed in LVEF, QRS width, NYHA, cardiovascular risk factors nor drug medication. Non-ischaemic dilated cardiomyopathy was significantly more present in R (71% vs 27%; p = 0.03). Before CRT, NR had more important left ventricular end-diatolic diameter, left ventricular end-systolic diameter and more elevated left pressions. Atrioventricular dyssynchrony was significantly more observed in R (66% vs 9%; p = 0.006) so as intraventricular dyssynchrony (95% vs 27%; p = 0.001).BNP is significantly more elevated in NR (602 ± 385 vs 320 ± 361; p = 0.03) before CRT.After 3 and 6 month, a significant decrease in left ventricular end-diatolic and end-systolic diameters, LVEF and normalisation of left and right pressions occur in R. Likewise, BNP levels were lower in R. NR patients have before implantation a more severe cardiomyopathy. At follow-up, left ventricular remodelling could only be observed in R patients. These data suggest that cardiac CRT should not be proposed too late so that left ventricular remodelling could be expected.