Po-03-229 distinct roles for electrocardiographic vs. echocardiographic lvh in sca risk stratification

In a pilot study, we have reported that ECG and echocardiographic LVH convey distinct risk information in patients with SCA, reflecting electrical vs anatomic remodeling. In fact, a subgroup of SCA cases manifest with isolated ECG LVH, without anatomic remodeling. To test this finding in a larger sample and evaluate determinants of isolated ECG LVH in individuals who suffer SCA. In a large, prospective population-based study in the Northwest US (catchment population, one million), cases of SCA were compared to controls recruited from the same geographical area. A novel archive of SCA cases that underwent both ECG and Echo prior and unrelated to their SCA event was analyzed. The independent association of ECG LVH and Echo LVH with SCA was tested. We also compared characteristics of individuals with isolated ECG LVH vs. anatomic LVH separately in cases as well as controls. SCA Cases (n=626; 68 ± 14 years; 62% male), compared to controls (n= 477; 67 ± 11 years; 65% male) were more likely to have both ECG LVH (18% vs. 10%; p<0.001) and echocardiographic LVH (34.0% vs. 17%; p<0.001). However, there was poor agreement between the tests (kappa statistic = 0.18). A large subgroup of patients with ECG LVH (52%) did not have Echo LVH; conversely 74% of patients with echocardiographic LVH did not have ECG LVH. In multivariate analysis, ECG LVH was significantly associated with SCA (OR 1.6; 95% CI 1.1-2.3; p=0.03) independent of Echo LVH (OR 2.0; 95% CI 1.4–2.7; p=0.001). In cases, comprehensive comparisons of demographics, most co-morbidities and medications between isolated ECG LVH (n=53) and Echo LVH (n=214) did not reveal any significant differences. Prevalence of chronic renal insufficiency (38% vs. 58%, p=0.04) and LV ejection fraction <35% (13% vs. 27%, p=0.03) was moderately lower in cases with isolated ECG LVH. We confirm that ECG LVH and Echo LVH confer independent increased risk of SCA and should be considered separately in risk prediction algorithms. Isolated ECG LVH did not segregate with distinct demographic or clinical findings, suggesting that a special genetic contribution to development of ECG LVH should be investigated.