Prediction of superresponse to cardiac resynchronisation therapy in patients with congestive heart failure
The aim. To evaluate clinical, morphological, functional features and mortality in patients with congestive heart failure (CHF) and super-response to cardiac resynchronization therapy (CRT), to assess presence and severity of mechanical dyssynchrony in patients with super-response and to find potential predictors of super-response to CRT Methods. 106 CRT patients (mean age 54.7 ± 9.9 years; 83% men) with CHF II-IV NYHA functional class were enrolled for the study. At baseline and each 6 months after implantation clinical, electrocardiographic and echocardiographic parameters, NT-proBNP level were evaluated. According to the best decrease of left ventricular end-systolic volume (LVESV) (mean follow-up period 34.9 ± 16.1 months) patients were classified as super-responders (SR) (n = 45; reduction in LVESV >30%) and non-SR (n = 61; reduction in LVESV <30%). Results. At baseline groups were matched for main clinical characteristics. The proportion of patients with atrial fibrillation, width of the QRS complex, and the presence of left bundle-branch block were comparable between groups. Parameters of mechanical dyssynchrony were higher in SR: left ventricular pre-ejection period (LVPEP) (153.0 ± 35.9 ms vs 126.6 ± 35.1 ms; р = 0.005), interventricular mechanical delay (55.9 ± 30.8 ms vs 40.4 ± 29.9 ms; р = 0.049), systolic dyssynchrony index (9.6 ± 2.6% vs 7.2 ± 0.7%; р = 0.048). NT-proBNP level was lower in SR. SR demonstrated better dynamics of LVESV, LVEF. At baseline and in dynamics level of NT-proBNP was lower in SR. In both groups NT-proBNP decreased significantly, but reduction of NT-proBNP was more evident in SR. The survival rates were 100%in SR and 83.6% in non-SR (log rank test p = 0.002).According to multiple logistic regression analysis LVPEP (HR 1.025; 95% CI 1.006-1.044; p = 0.010) and baseline NT-proBNP level (HR 0.624; 95% CI 0. 426-0.913; p = 0.015) were independent predictors for CRT super-response with sensitivity 71.9% and specificity 78.6%. Conclusion. In patients with CHF greater mechanical dyssynchrony and lower level of NT-proBNP are associated with CRT super-response. SR demonstrate better survival and better dynamics of functional parameters in long-term period. LVPEP and NT-proBNP level can be used as independent predictors of CRT super-response.