Exercise tolerance test for predicting coronary heart disease in asymptomatic individuals: A review

In symptom-free subjects, exercise tolerance testing (ETT) has a doubtful utility for detecting latent coronary heart disease (CHD) because of frequent false positives, but it may be valuable for predicting future CHD. To clarify the latter question, we calculated CHD incidence associated with presence or absence of ETT-induced abnormalities of ST-segment depression, exercise capacity, and heart rate using published prospective ETT studies in primary prevention populations. Based on 5-23 years of follow-up, yearly incidence of fatal and non-fatal CHD ranged from 0.9 to 5.8% in the presence of ST-segment depression and from 1.2 to 1.7% in the presence of impaired maximal heart rate, and pooling of all data provided a linear positive relationship between pre- and post-test CHD incidence. Yearly incidence of CHD death was 0.8% in the presence of ST-segment depression, 0.2-0.3% in the presence of impaired heart rate recovery, and 0.5% in the presence of low exercise capacity. Absence of ST-segment depression was associated with <1.5% yearly incidence of fatal and non-fatal CHD events, except for one study and <0.2% yearly incidence of CHD or CVD death in all populations analyzed. Lastly ETT-induced ST-segment depression conveys a CHD risk superior to that associated with ETT-induced heart rate and exercise capacity abnormalities. This may be due to difference in pretest CHD incidences in ETT studies.