Electrocardiographic and Echocardiographic Left Ventricular Hypertrophy in the Prediction of Stroke in the Elderly

Introduction: It is unclear whether left ventricular hypertrophy (LVH) detected by electrocardiography (ECG-LVH) is equally predictive of heart failure as LVH detected by echocardiography (echo-LVH). Methods: This analysis included 4,008 white participants (41% men) aged 65 years or older from the Cardiovascular Health Study who were free of stroke and major intraventricular conduction defects. ECG-LVH was defined by the Cornell criteria from baseline ECG data and echo-LVH was calculated from baseline echocardiography measurements. Cox regression was used to compute hazard ratios (HRs) and 95% confidence intervals (CIs) for the association between ECG-LVH and echo-LVH and adjudicated incident stroke events, separately. Harrell's concordance indices (C-index) were calculated for the Framingham Stroke Risk Score with inclusion of ECG-LVH and echo-LVH, separately. Results: ECG-LVH was detected in 136 (3.4%) participants and echo-LVH was present in 208 (5.2%) participants. Over a median follow-up of 13 years, a total of 769 (19%; incidence rate 515.4 per 1000 person-years) strokes occurred. In a multivariable Cox regression analysis adjusted for stroke risk factors and potential confounders, ECG-LVH (HR = 1.68; 95% CI = 1.23, 2.28) and echo-LVH (HR = 1.58; 95% CI = 1.17, 2.14) were associated with an increased risk of stroke. Similar values were obtained for the C-index when either ECG-LVH (C-index 5.786) or echo-LVH (C-index 5.786) were included in the Framingham Stroke Risk Score. Conclusion: ECG-LVH and echo-LVH are able to be used interchangeably in stroke risk scores. (C) 2015 by National Stroke Association