Electrocardiographic predictors of echocardiographic response in cardiac resynchronization therapy: Update of an old story

Background: A better selection of patients with left bundle branch block (LBBB) might increase the response to cardiac resynchronization therapy (CRT). The aim of the study was to investigate the association between the Strauss criteria, absence of S wave in V5-V6, the Selvester score and response to CRT. Methods and results: The retrospective analysis included all consecutive patients having undergone implantation of biventricular defibrillators in primary prevention between 2018 and 2020. The final analysis included 236 patients (mean age 69.7 +/- 9.9; 77.5% of males). The Strauss criteria were significantly associated with CRT response (p < 0.01) with a sensitivity of 71.3% and specificity of 64.1%. The Strauss criteria along with the absence of S wave in V5 and V6 showed a sensitivity of 56.7%, a specificity of 82.6% and a positive predictive value of 90.5%. The Selvester score was significantly and inversely associated with CRT response (OR 0.818, 95% CI 0.75-0.89; p < 0.001). The multivariable model showed that left ventricular ejection fraction (LVEF) and QRS duration (>= 140 ms in males and >= 130 ms in females) were independently associated with CRT response (respectively OR 0.92, CI 95% 0.86-0.98, p = 0.01 and OR 3.70, CI 95% 1.12-12.21, p = 0.03). Conclusions: Strauss criteria, especially in association with absence of S wave in V5 and V6, were able to increase specificity and positive predictive value for predicting CRT response. The Selvester score was inversely associated with CRT response. Finally, LVEF and QRS duration were independently associated with echocardiographic response to CRT.