Myocardial recovery after cardiac resynchronization therapy in left bundle branch block‐associated idiopathic nonischemic cardiomyopathy: A NEOLITH II substudy

• Published in: Annals of noninvasive electrocardiology Vol. 24; no. 2; pp. e12603 - n/a
• Main Authors: 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
• Format: Journal Article
• Language: English
• Published: United States John Wiley & Sons, Inc 01.03.2019; John Wiley and Sons Inc
• Subjects: Academic Medical Centers; Aged; Analysis of Variance; Bundle-Branch Block - diagnostic imaging; Bundle-Branch Block - epidemiology; Bundle-Branch Block - therapy; cardiac resynchronization therapy; Cardiac Resynchronization Therapy - methods; Cardiac Resynchronization Therapy - mortality; Cardiomyopathies - diagnosis; Cardiomyopathies - epidemiology; Cardiomyopathies - therapy; Cardiomyopathy; Cause of Death; Cohort Studies; Comorbidity; Confidence intervals; Congestive heart failure; Defibrillators; Female; Heart rate; Heart transplantation; Humans; Hypertension; Implantation; left bundle branch block; left ventricular ejection fraction; Logistic Models; Male; Middle Aged; Myocardial Ischemia; myocardial recovery; nonischemic cardiomyopathy; Original; outcomes; Pennsylvania; Prognosis; Proportional Hazards Models; Recovery; Recovery of Function - physiology; Regression analysis; Retrospective Studies; Severity of Illness Index; Statistical analysis; Stroke Volume - physiology; Survival Rate; Tachycardia; Therapy; Transplantation; Treatment Outcome; Urea; Ventricle; Ventricular Remodeling - physiology; Pennsylvania; left bundle branch block; nonischemic cardiomyopathy; cardiac resynchronization therapy; myocardial recovery; outcomes; left ventricular ejection fraction
• ISSN: 1082-720X; 1542-474X; 1542-474X
• DOI: 10.1111/anec.12603

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.