Complementary value of ECG and echocardiographic left ventricular hypertrophy for prediction of adverse outcomes in the general population

OBJECTIVE: To investigate whether ECG left ventricular hypertrophy (ECG-LVH) has prognostic value independent of echocardiography LVH (Echo-LVH). METHODS: Participants (N = 9744, mean age, 53.81 ± 10.49 years and 45.5% male) from the Northeast China Rural Cardiovascular Health Study were included. Associations between Echo-LVH (sex-specific left ventricular mass normalized to BSA) and ECG-LVH (diagnosed using the Cornell-voltage duration product) and adverse outcomes were evaluated using Cox regression. The value of ECG-LVH for predicting adverse events was evaluated by reclassification and discrimination analyses. RESULTS: Median follow-up was 4.65 years; 563 participants developed incident stroke or coronary heart disease (CHD) and 402 died. Compared with participants without either condition, those with both Echo-LVH and ECG-LVH had a significantly increased risk of incident stroke or CHD (hazard ratio, 2.42; 95% confidence interval, 1.82-3.22) and mortality (2.58; 1.85-3.60). ECG-LVH remained an independent risk factors for both outcomes when ECG-LVH and Echo-LVH were included in the model as separate variables incident stroke or CHD (1.43; 1.14-1.79); mortality (1.41; 1.08-1.84). Reclassification and discrimination analyses indicated ECG-LVH addition could improve the conventional model for predicting adverse outcomes within 4 years. These relationships persisted after excluding participants with cardiovascular disease history or taking antihypertension drugs or upon applying other ECG-LVH and Echo-LVH diagnostic criteria. CONCLUSION: Our study provides strong evidence that ECG-LVH is associated with adverse outcomes, independent of Echo-LVH. Clinically, ECG-LVH could be considered as a consequential factor, especially in those with Echo-LVH. These findings have potential clinical relevance for risk stratification.