Background: Early identification of patients at risk for coronary heart disease (CHD) is crucial to formulate effective preventive strategies. Therefore, our aim was to compare the predictive value for CHD of two measures - exercise electrocardiography (Ex ECG) and coronary artery calcifications (CAC).
Design: Prospective study.
Methods: During 2001, 566 asymptomatic subjects performed a treadmill exercise test and underwent an unenhanced computed tomography to assess CAC. Patients were followed until December 2012. The associations between Ex ECG, CAC and coronary events were analyzed.
Results: An abnormal Ex ECG was found in 71 (12.5%) subjects and CAC in 286 (50.5%) subjects. During a mean follow-up of 6.5 ± 3.3 years, 35 subjects experienced a first coronary event. Among those with an abnormal Ex ECG, 14 (19.7%) experienced an event; among those with CAC, 31(11%) experienced an event. Subjects with both CAC and an abnormal Ex ECG had the highest rate of coronary events 13/39 (33%). Among those without CAC, the rate of coronary events was low (4/280) (1.4%) regardless of the Ex ECG results. Compared with those without CAC and a normal Ex ECG, the adjusted hazard ratio for coronary events was 4.70 (95% CI; 1.32-16.73) in those with CAC and a normal Ex ECG, and 21.5 (95% C.I; 5.68-81.30) in those with CAC and an abnormal Ex ECG.
Conclusions: In subjects with CAC, further risk stratification can be achieved by an Ex ECG, whereas in those without CAC, an Ex ECG has no incremental value in predicting coronary events.
