Impact of Adverse Left Ventricular Remodeling on Sudden Cardiac Death in Patients With Hypertrophic Cardiomyopathy

Background: Adverse left ventricular (LV) remodeling predicts heart failure symptoms and overt LV dysfunction in patients with hypertrophic cardiomyopathy (HCM), but its influence on the occurrence of sudden cardiac death (SCD) is unknown. The aim of this study was to investigate the effect of adverse LV remodeling on SCD risk in patients with HCM. Hypothesis: Adverse LV remodeling increases SCD in HCM patients. Methods: This study included 41 patients with HCM who experienced SCD; each case was matched with 3 controls based on age, gender, and time of first contact. In this population of 164 patients, predictors of SCD were identified using univariable and multivariable logistic regression and expressed as odds ratio (OR) with 95% confidence interval (CI). Results: Baseline characteristics, such as New York Heart Association (NYHA) class, systolic and diastolic left ventricular function, left ventricular wall thickness, left atrial size, atrial fibrillation, and established risk factors for SCD were similar in cases and controls. Independent predictors of SCD during follow-up (median follow-up, 7.7 +/- 6.5 years) were: increase in NYHA class (OR: 8.7 [95% CI: 2.5-30.5], P=0.001), decrease of fractional shortening (per % decrease, OR: 1.09 [95% CI: 1.03-1.14], P=0.001), and decrease of diastolic function (OR: 3.5 [95% CI: 1.2-10.2], P=0.02). Conclusions: This study shows that SCD risk in HCM increases when adverse remodeling occurs. Because cases and controls were similar at baseline, these findings emphasize the importance of vigilant follow-up of HCM patients and could aid clinical decision making concerning implantable cardioverter-defibrillator implantation, especially in patients with moderate risk for SCD.