Combined electrical and global markers of dyssynchrony predict clinical response to Cardiac Resynchronization Therapy

Aim. To assess potential additional value of global left ventricular (LV) dyssynchrony markers in predicting cardiac resynchronization therapy (CRT) response in heart failure (HF) patients. Methods. We included 103 HF patients (mean age 67 +/- 12 years, 83% male) who fulfilled the guidelines criteria for CRT treatment. All patients had undergone full clinical assessment, NT-proBNP and echocardiographic examination. Global LV dyssynchrony was assessed using total isovolumic time (t-IVT) and Tei index. On the basis of reduction in the NYHA class after CRT, patients were divided into responders and non-responders. Results. Prolonged t-IVT [0.878 (range, 0.802-0.962), p = 0.005], long QRS duration [0.978 (range, 0.960-0.996), p = 0.02] and high tricuspid regurgitation pressure drop [1.047 (range, 1.001-1.096), p = 0.046] independently predicted response to CRT. A t-IVT >= 11.6 s/min was 67% sensitive and 62% specifi c (AUC 0.69, p = 0.001) in predicting CRT response. Respective values for a QRS >= 151 ms were 66% and 62% (AUC 0.65, p = 0.01). Combining the two variables had higher specifi city (88%) in predicting CRT response. In atrial fibrillation (AF) patients, only prolonged t-IVT [0.690 (range, 0.509 -0.937), p = 0.03] independently predicted CRT response. Conclusion. Combining prolonged t-IVT and the conventionally used broad QRS duration has a significantly higher specifi city in identifying patients likely to respond to CRT. Moreover, in AF patients, only prolonged t-IVT independently predicted CRT response.