IMPACT OF ANTIANGINAL MEDICATIONS, PEAK HEART-RATE AND STRESS LEVEL ON THE PROGNOSTIC VALUE OF A NORMAL EXERCISE MYOCARDIAL PERFUSION IMAGING STUDY

We sought to determine whether antianginal medications or the level of achieved stress affect the prognostic value of a normal exercise Tl-201 study. We studied 261 patients with a normal exercise Tl-201 study for 23 +/- 6 mo. Antianginal medications were taken at the time of stress testing in 128 patients. Peak heart rate ranged from 82 to 217 bpm; percent maximal predicted heart rate ranged from 42% to 136%. Chi-square analysis was used to determine the relationship of cardiac events to antianginal medications and stress indices. Primary cardiac events were defined as cardiac death or nonfatal myocardial infarction. Primary cardiac events occurred in six patients yielding an annual incidence of 1.2% per year. There was no significant relationship between cardiac event rate and antianginal medication use or any stress index, including Bruce stage, peak heart rate or blood pressure or percent maximal predicted heart rate achieved. The risk of cardiac death or nonfatal myocardial infarction in patients with a normal exercise Tl-201 is low and is not affected by concurrent antianginal treatment or degree of stress achieved.