Association between QT interval and coronary heart disease in middle-aged and elderly men: The Zutphen study

Abstract

Background: Heart-rate-adjusted QT-interval (QT(c)) is prognostic of sudden death in myocardial infarction patients. So far, population studies have yielded conflicting results on the predictive value of QT(c) for coronary heart disease morbidity and mortality. Therefore, we investigated this in a longitudinal study of middle-aged and elderly men. Methods and Results: From 1960 to 1985, 877 middle-aged men were followed and repeatedly examined in the Zutphen Study. In 1985 the remaining cohort was extended to 835 elderly men from the same birth cohort and followed until 1990. Men with prolonged QT(c) (420 ms( 1/2 ) or more) had a higher risk of myocardial infarction and coronary heart disease death relative to men with QT(c) less than 385 ms( 1/2 ). Age-adjusted coronary heart disease mortality rate ratios were 4.3 (95% confidence interval, 1.3 to 13.8) in middle-aged men and 3.3 (95% confidence interval, 1.0 to 11.6) in elderly men. These associations could not be attributed to prevalent heart disease and were independent of other cardiovascular risk factors. Conclusions: These results indicate that within the normal range of QT(c) in the general population, men with long QT(c) are at higher risk for coronary heart disease. Because QT(c) is easily determined, it may provide a valuable contribution to risk stratification.