New criteria to enhance the predictability of coronary artery disease by exercise testing in asymptomatic subjects.

Thirty-seven subjects (10 asymptomatic and 27 symptomatic) who had undergone maximal treadmill exercise tests and coronary arteriography were selected to determine whether the predictive value of ST-segment depression as a marker of coronary artery disease (CAD) in asymptomatic subjects could be enhanced. All subjects had greater than or equal to 2 mm ST-segment depression during testing. Three of the ten asymptomatic subjects had significant CAD (predictive accuracy 30%) and all had greater than or equal to 2 mm ST depression in the one-minute recovery tracing. ST-segment depression resolved by one minute in all seven subjects without CAD. All 27 symptomatic subjects had CAD (predictive accuracy 100%) and 26 of 27 had greater than or equal to 1 mm (21/24 greater than or equal to 2 mm) ST depression in the one-minute recovery tracing. The age, maximum heart rate and exercise tolerance did not differ significantly between the symptomatic and asymptomatic subjects. Thus the predictive accuracy for CAD in asymptomatic subjects is not enhanced by increasing the degree of ST depression required for a positive exercise test. The predictive value may be enhanced if ST depression persists for greater than or equal to 2 minutes into recovery. These data suggest that by using new criteria accurate identification of asymptomatic patients with CAD by exercise testing may be practical.