Electrocardiographic abnormalities and 30-year mortality among white and black men of the Charleston Heart Study.

BACKGROUND The long-term predictive significance of a single ECG tracing for mortality was explored among the white and black men of the Charleston Heart Study. METHODS AND RESULTS The 1960 baseline tracings of men ages 35 to 74 in the Charleston Heart Study cohort were coded according to the Minnesota classification. Tracings were categorized as being normal or having minor or major abnormalities. The 30-year vital status was ascertained for the cohort, and the association between ECG findings and coronary and all-cause mortality was evaluated. The proportion of black men with major abnormalities at the 1960 baseline examination was almost twice that of white men. Rates of all-cause mortality increased with severity of abnormalities for white and black men. The absolute excess risk for black men with major abnormalities was 23.3 per 1000 person-years and 12.8 for white men. The excess risk for coronary mortality was 7.3 for white men and 6.5 for black men. CONCLUSIONS Many of the findings in this study confirm earlier associations derived from studies of white populations and extend the observations to black men. However, the magnitude of the relative risk for mortality was different for white and black men. After controlling for traditional coronary disease risk factors and minor abnormalities, white men with major abnormalities were 2.72 (95% confidence interval, 1.47, 5.04) times more likely to die of coronary disease compared with black men, who were 1.95 (95% confidence interval, 0.93, 4.11) times more likely to die of coronary disease.