Open AccessMyocardial recovery after cardiac resynchronization therapy in left bundle branch block‐associated idiopathic nonischemic cardiomyopathy: A NEOLITH II substudy
Author(s) -
Wang Norman C.,
Hussain Aliza,
Adelstein Evan C.,
Althouse Andrew D.,
Sharbaugh Michael S.,
Jain Sandeep K.,
Shalaby Alaa A.,
Voigt Andrew H.,
Saba Samir
Publication year - 2019
Publication title -
annals of noninvasive electrocardiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.494
H-Index - 48
eISSN - 1542-474X
pISSN - 1082-720X
DOI - 10.1111/anec.12603
Subject(s) - medicine , cardiology , ejection fraction , cardiac resynchronization therapy , left bundle branch block , heart failure , hazard ratio , cardiomyopathy , odds ratio , heart transplantation , implantable cardioverter defibrillator , ventricular tachycardia , confidence interval
Background Baseline predictors of myocardial recovery after cardiac resynchronization therapy (CRT) in left bundle branch block (LBBB)‐associated idiopathic nonischemic cardiomyopathy (NICM) are unknown. Methods A retrospective study included subjects with idiopathic NICM, left ventricular ejection fraction (LVEF) ≤35%, and LBBB. Myocardial recovery was defined as post‐CRT LVEF ≥50%. Logistic regression analyses described associations between baseline characteristics and myocardial recovery. Cox regression analyses estimated the hazard ratio (HR) between myocardial recovery status and adverse clinical events. Results In 105 subjects (mean age 61 years, 44% male, mean initial LVEF 22.6% ± 6.6%, 81% New York Heart Association class III, and 98% CRT‐defibrillators), myocardial recovery after CRT was observed in 56 (54%) subjects. Hypertension, heart rate, and serum blood urea nitrogen (BUN) had negative associations with myocardial recovery in univariable analyses. These associations persisted in multivariable analysis: hypertension (odds ratio (OR), 0.40; 95% confidence interval (CI), 0.17–0.95; p = 0.04), heart rate (OR per 10 bpm, 0.69; 95% CI, 0.48–0.997; p = 0.048), and serum BUN (OR per 1 mg/dl, 0.94; 95% CI, 0.88–0.99; p = 0.04). Subjects with post‐CRT LVEF ≥50%, when compared to <50%, had lower risk for adverse clinical events (heart failure hospitalization, appropriate implantable cardioverter‐defibrillator shock, appropriate anti‐tachycardia pacing therapy, ventricular assist device implantation, heart transplantation, and death) over a median follow‐up of 75.9 months (HR, 0.38; 95% CI, 0.16–0.88; p = 0.02). Conclusion In LBBB‐associated idiopathic NICM, myocardial recovery after CRT was associated with absence of hypertension, lower heart rate, and lower serum BUN. Those with myocardial recovery had fewer adverse clinical events.