Prognostic Value of Electrocardiographic Left Ventricular Hypertrophy on Cardiovascular Risk in a Non-Hypertensive Community-Based Population

BACKGROUND The appearance of left ventricular hypertrophy on 12-lead electrocardiography (ECG-LVH) has been clarified to be associated with the risk of incidence of cardiovascular events (CVEs) in hypertensive individuals and the general population, but not enough in non-hypertensive individuals. METHODS A total of 4,927 non-hypertensive individuals >= 40 years of age who were free of CVE in the general population were followed for the incidence of CVE. ECG-LVH was defined according to criteria of the Sokolow-Lyon (SL) voltage, Cornell voltage (CV), or Cornell voltage product (CP). RESULTS During the average 9.8 +/- 2.0 years of follow-up, 267 individuals (5.4%) had their first CVE. The hazard ratio (HR) for the incidence of CVE after full adjustment by potential confounders significantly increased in the individuals with ECG-LVH by any criteria of the SL voltage, CV, and CP HR = 1.77, P < 0.001) compared to those with no ECG-LVH. This association was also significant in individuals without any of obesity, dyslipidemia, and diabetes mellitus or those with systolic blood pressure (BP) <120 mm Hg and diastolic BP <80 mm Hg. Furthermore, ECG-LVH by each criteria provided the reclassification improvement for the CVE risk prediction model by the Framingham 10-year risk score (the net reclassification improvement = 0.17-0.22, each P value < 0.010). CONCLUSIONS In the absence of hypertension, ECG-LVH parameters are associated with the increased risk of developed CVEs independent of the established risk factors and provide the additional prognostic value in an assessment of the CVE risk using the traditional risk factors.