Left Ventricular Dilatation Increases the Risk of Ventricular Arrhythmias in Patients With Reduced Systolic Function

Abstract

Background Reduced left ventricular (LV) ejection fraction increases the risk of ventricular arrhythmias; however, LV ejection fraction has a low sensitivity to predict ventricular arrhythmias. LV dilatation and mass may be useful to further risk‐stratify for ventricular arrhythmias. Methods and Results Patients from the Genetic Risk of Assessment of Defibrillator Events ( GRADE ) study (N=930), a study of heart failure subjects with defibrillators, were assessed for appropriate implantable cardioverter‐defibrillator shock and death, heart transplant, or ventricular assist device placement by LV diameter and mass. LV mass was divided into normal, mild, moderate, and severe classifications. Severe LV end‐diastolic diameter had worse shock‐free survival than normal and mild LV end‐diastolic diameter ( P =0.0002 and 0.0063, respectively; 2‐year shock free, severe 74%, moderate 80%, mild 91%, normal 88%; 4‐year shock free, severe 62%, moderate 69%, mild 72%, normal 81%) and freedom from death, transplant, or ventricular assist device compared with normal and moderate LV end‐diastolic diameter ( P <0.0001 and 0.0441, respectively; 2‐year survival: severe 78%, moderate 85%, mild 82%, normal 89%; 4‐year survival: severe 55%, moderate 64%, mild 63%, normal 74%). Severe LV mass had worse shock‐free survival than normal and mild LV mass ( P =0.0370 and 0.0280, respectively; 2‐year shock free: severe 80%, moderate 81%, mild 91%, normal 87%; 4‐year shock free: severe 68%, moderate 73%, mild 76%, normal 76%) but no association with death, transplant, or ventricular assist device ( P =0.1319). In a multivariable Cox proportional hazards analysis adjusted for LV ejection fraction, LV end‐diastolic diameter was associated with appropriate implantable cardioverter‐defibrillator shocks (hazard ratio 1.22, P =0.020). LV end‐diastolic diameter was associated with time to death, transplant, or ventricular assist device (hazard ratio 1.29, P =0.0009). Conclusions LV dilatation may complement ejection fraction to predict ventricular arrhythmias. Clinical Trial Registration URL: https://www.clinicaltrials.gov . Unique identifier: NCT02045043.