Left Ventricular Geometry and Risk of Sudden Cardiac Arrest in Patients With Severely Reduced Ejection Fraction

Recent reports indicate that specific left ventricular (LV) geometric patterns predict recurrent ventricular arrhythmias in patients with implantable cardioverter-defibrillators and reduced left ventricular ejection fraction (LVEF). However, this relationship has not been evaluated among patients at risk of sudden cardiac arrest (SCA) in the general population.

Adult SCA cases from the Oregon Sudden Unexpected Death Study were compared with geographic controls with no prior history of SCA. Archived echocardiograms performed closest and prior to the SCA event were reviewed. LV geometry was defined as normal (normal LV mass index [LVMI] and relative wall thickness [RWT]), concentric remodeling (normal LVMI and increased RWT), concentric hypertrophy (increased LVMI and RWT), or eccentric hypertrophy (increased LVMI and normal RWT). Analysis was restricted to those with LVEF ≤40%. A total of 246 subjects were included in the analysis. SCA cases (n=172, 68.6±13.3 years, 78% male), compared to controls (n=74, 66.8±12.1 years, 73% male), had lower LVEF (29.4±7.9% vs 30.8±6.3%, P=0.021). Fewer cases presented with normal LV geometry (30.2% vs 43.2%, P=0.048) and more with eccentric hypertrophy (40.7% vs 25.7%, P=0.025). In a multivariate model, eccentric hypertrophy was independently predictive of SCA (OR 2.15, 95% CI 1.08-4.29, P=0.03).

Eccentric LV hypertrophy was independently associated with increased risk of SCA in subjects with EF ≤40%. These findings, now consistent between device-implanted and non-implanted populations, indicate the potential of improving SCA risk stratification from the same noninvasive echocardiogram at no additional cost.