ST segment and T wave characteristics as indicators of coronary heart disease risk: the Zutphen Study
JM Dekker,
EG Schouten,
P Klootwijk,
J Pool,
and
D Kromhout
Department of Epidemiology and Public Health, Agricultural University Wageningen, The Netherlands.
OBJECTIVES. This study evaluated the predictive value of T wave amplitude and ST segment level on lead I for angina pectoris, a first myocardial infarction, sudden death and coronary heart disease death in middle-aged and elderly men. BACKGROUND. Certain ST-T wave characteristics may reflect favorable autonomic cardiac control. Slight ST segment elevation has been reported to indicate a low risk of coronary heart disease mortality. METHODS. A total of 876 men, born between 1900 and 1920, participated in periodic medical examinations and were followed up with respect to morbidity and mortality from 1960 to 1985. In 1985, the remaining cohort was extended to 836 elderly men from the same birth cohort who were followed up until 1990. Relative risks in categories of T wave amplitude and ST segment level were estimated by survival analysis. RESULTS. Both middle-aged and elderly men with T wave amplitudes > or = 0.15 mV had a lower risk of myocardial infarction, coronary heart disease death and sudden death than men with T wave amplitudes 0.05 to 0.15 mV. The adjusted relative risk of coronary heart disease death was 0.5 (95% confidence interval [CI] 0.2 to 1.0); in men with T wave amplitude < or = 0.05 mV, relative risk was 2.0 (95% CI 1.3 to 3.1). Slight ST segment elevation was also associated with decreased risk: relative risk 0.5 (95% CI 0.3 to 1.0) compared with the isoelectric ST segment level. In men with ST segment depression, relative risk was 2.2 (95% CI 1.4 to 3.4). The association of T wave amplitude and ST segment level were independent of each other. CONCLUSIONS. In addition to the elevated risk of coronary heart disease that is associated with ST-T wave abnormalities, we observed that normal variations in repolarization characteristics are predictive of future heart disease.
