Effect of Type A behavior on exercise test outcome in coronary artery disease

The outcome of the diagnostic exercise test depends on such patient-related factors as age, maximum exercise heart rate, exercise time and severity of the underlying coronary artery disease (CAD). This study examined the hypothesis that type A behavior would affect the amount of effort expended, as indicated by the exercise time and the maximum heart rate achieved, thereby resulting in differences in exercise test outcome. A total of 1,260 patients with suspected CAD, all of whom had coronary angiography, a structured interview to assess type A behavior and a treadmill exercise test, participated. Of these patients, 818 (65%) had significant CAD, and 852 (68%) were type A. There were no differences between type A and B patients in either maximum heart rate or total exercise time. Among both type A and B subjects, 36% of treadmill tests were positive. Exercise test sensitivity was similar for both groups (69% for type A vs 72% for type B, p = 0.39). Similarly, specificity was similar for both groups (87% for type A vs 80% for type B, p = 0.09). Results did not change after using logistic regression to control for potential confounding factors. Thus, type A behavior does not need to be taken into account when interpreting exercise test outcome.