Abstract
BACKGROUND: Left ventricular hypertrophy (LVH) is associated with increased risk of sudden cardiac arrest (SCA). Whether LVH diagnosed by 12-lead ECG vs echocardiogram conveys identical or distinct risk information has not been previously evaluated. OBJECTIVE: The purpose of this study was to compare the association between ECG vs echocardiographic LVH and SCA in the community. METHODS: In a large, prospective population-based study (The Oregon Sudden Unexpected Death Study; population approximately 1 million), cases of SCA were compared to controls recruited from the same geographical area. The association between LVH and SCA was evaluated, specifically comparing LVH diagnosed by ECG vs echocardiogram. RESULTS: Cases (n = 132, age 66.9 ± 13.5 years, 58.3% male) compared to controls (n = 211; age 66.2 ± 12 years, 59.2% male) were more likely to have both ECG LVH (12.1% vs 5.7%, P = .03) and echocardiographic LVH (35.0% vs 15.5%, P <.001). However, there was poor agreement between the tests (kappa statistic = 0.128). A large subgroup of patients with ECG LVH (57.1%) did not have echocardiographic LVH; conversely, 83.6% of patients with echocardiographic LVH did not have ECG LVH. In multivariate analysis, ECG LVH was significantly associated with SCA (odds ratio [OR] 2.5, 95% confidence interval [CI] 1.1-6.0, P = .04). When echocardiographic LVH was added to the model, this association was only mildly attenuated (OR 2.4, 95% CI 1.0-6.0, P= .05), and echocardiographic LVH was also independently associated with SCA (OR 2.7, 95% CI 1.5-4.9, P = .001). CONCLUSION: ECG and echocardiographic LVH may convey distinct risk information in patients with SCA, reflecting electrical vs anatomic remodeling. These findings have potential implications for SCA mechanisms and risk stratification.