Abstract 17546: Electrocardiography and Holter Insight Into Sudden Cardiac Death Risk in Hypertrophic Cardiomyopathy
Introduction: While multiple studies have evaluated risk factors for sudden cardiac death (SCD) in hypertrophic cardiomyopathy (HCM), risk stratification and clinical decision-making regarding implantable cardioverter defibrillator (ICD) implantation remains complex. The goal of this study was to assess electrocardiogram (ECG) and ambulatory Holter monitor-derived risk factors for SCD in a large HCM population.
Methods: Retrospective review of adults with HCM evaluated at Mayo Clinic, Rochester, MN from 12/1/2002- 12/31/2012 was performed. Data inclusive of ECG and 24 hour ambulatory Holter monitor were assessed. SCD was documented by history, ventricular tachycardia (VT) or ventricular fibrillation (VF) noted on ICD, or appropriate VF-terminating ICD shock. Student’s T-test, Pearson chi-square, and multivariable logistics regression model were conducted as appropriate.
Results: Overall, 1615 patients (mean age 53.7 ± 15.2 years; 943 males, 58.4%) were assessed, with mean follow-up 2.46 years (range 1 day - 13.37 years) and 110 SCD events. Multivariate analysis confirmed current knowledge that nonsustained ventricular tachycardia (NSVT) on Holter was a risk factor for SCD (p<0.0001). NSVT (p=0.0003) and QTc ≥440 ms on ECG (p=0.008) were strong predictors of SCD even after controlling for wall thickness >30mm, family history of SCD, prior VT/VF, prior ICD placement and syncope. QTc was used for analysis only when QRS was < 200ms (n=826). There was no correlation between sinus bradycardia, sinus tachycardia, first degree AV block, atrial fibrillation, left bundle branch block, right bundle branch block, premature atrial complexes, premature ventricular complexes, supraventricular tachycardia, PR interval, QRS interval and SCD. There was no discernible protective effect from SCD associated with beta-blocker, disopyramide, amiodarone, digoxin or other anti-arrhythmic medication use.
Conclusion: Our study represents one of the largest, single center cohorts of HCM patients to be assessed for electrocardiographic/arrhythmic risk factors in SCD. NSVT and prolonged QTc were risk factors for SCD even when controlling for typical risk factors.
Author Disclosures: S.I. Patel: None. W.T. Love: None. M.J. Ackerman: Consultant/Advisory Board; Modest; Boston Scientific, Gilead Sciences, Medtronic, and St. Jude Medical. Other; Significant; Transgenomic. J.B. Geske: None. J.M. Bos: None. S.R. Ommen: None. S.S. Cha: None. S.J. Lester: None. F. Mookadam: None. F.E. Shamoun: None.
- © 2016 by American Heart Association, Inc.