Preimplantation interlead ECG heterogeneity is superior to QRS complex duration in predicting mechanical super-response in patients with non-left bundle branch block receiving cardiac resynchronization therapy

Abstract

BACKGROUND Reliable quantitative preimplantation predictors of response to cardiac resynchronization therapy (CRT) are needed. OBJECTIVE We tested the utility of preimplantation R-wave and T-wave heterogeneity (RWH and TWH, respectively) compared to standard QRS complex duration in identifying mechanical super-responders to CRT and mortality risk. METHODS We analyzed resting 12-lead electrocardiographic recordings from all 155 patients who received CRT devices between 2006 and 2018 at our institution and met class I and IIA American College of Cardiology/American Heart Association/Heart Rhythm Society guidelines with echocardiograms before and after implantation. Super-responders (n=35, 23%) had >= 20% increase in left ventricular ejection fraction and/or >= 20% decrease in left ventricular end-systolic diameter and were compared with non-super-responders (n=120, 77%), who did not meet these criteria. RWH and TWH were measured using second central moment analysis. RESULTS Among patients with non-left bundle branch block (LBBB), preimplantation RWH was significantly lower in super-responders than in non-super-responders in 3 of 4 lead sets ( P=.001 to P=.038) and TWH in 2 lead sets (both, P=.05), with the corresponding areas under the curve (RWH: 0.810-0.891, P<.001; TWH: 0.759-0.810, P <=.005). No differences were observed in the LBBB group. Preimplantation QRS complex duration also did not differ between super-responders and non-super-responders among patients with ( P=.856) or without ( P=.724) LBBB; the areas under the curve were nonsignificant (both, P=.69). RWH V1-3LILII >= 420 mu V predicted 3-year all-cause mortality in the entire cohort ( P=.037), with a hazard ratio of 7.440 (95% confidence interval 1.015-54.527; P=.048); QRS complex duration >= 150 ms did not predict mortality ( P=.27). CONCLUSION Preimplantation interlead electrocardiographic heterogeneity but not QRS complex duration predicts mechanical super-response to CRT in patients with non-LBBB.