Electrocardiographic left ventricular hypertrophy predicts arrhythmia and mortality in patients with ischemic cardiomyopathy.

PURPOSE: The relatively low incidence of device-treated ventricular arrhythmias in patients with ischemic cardiomyopathy (ICM) who receive implantable cardioverter defibrillators (ICDs) for primary prevention makes improved risk stratification of ICM patients a priority. Although Cornell product (CP) ECG left ventricular hypertrophy (LVH) has been associated with increased mortality in hypertensive patients and population-based studies, whether CP LVH can improve risk stratification of high-risk ICM patients is unclear. The aim of this study is to examine if electrocardiographic LVH predicts mortality and incident ventricular arrhythmia in patients with ICM.
METHODS: All-cause mortality was examined in 317 patients with ICM and a history of non-sustained ventricular tachycardia (VT) who underwent electrophysiology testing. Incident VT and ventricular fibrillation (VF) were assessed in ICD recipients (n = 186). ECG LVH was defined by CP criteria: [(R (aVL) + S (V3)) + 6 mm in women] × QRS duration >2,440 mm ms.
RESULTS: During 3 years of follow-up, mortality was 20% (64 of 317) and death or incident VT or VF occurred in 35% of ICD recipients. CP LVH was associated with significantly greater 3-year mortality (28% vs 15%, p = 0.015) and 3-year mortality or incident VT/VF in ICD patients (48% vs 35%, p = 0.011). In Cox multivariate models, CP LVH was an independent predictor of mortality in all patients (hazard ratio (HR) 1.81, 95% confidence interval (CI) 1.11-2.97, p = 0.020) and of the composite endpoint of mortality or incident ventricular arrhythmia in ICD patients (HR 1.82, 95% CI 1.12-3.00, p = 0.016).
CONCLUSIONS: ECG LVH using CP criteria may enhance risk stratification in high-risk patients with ICM.