OBJECTIVE To investigate the "toxic" total (potential for) hostility component of the type A behavior pattern (assessed by means of the structured interview) as it relates to prediction of restenosis after percutaneous transluminal coronary angioplasty (PTCA). METHODS Patients with single vessel or multivessel coronary artery disease in whom PTCA had been scheduled or done were administered the structured interview by one trained interviewer prospectively or retrospectively (blinded to angiographic endpoints). METHODS A total of 41 patients underwent 53 initial balloon dilations on native arteries by 1 of 5 participating cardiologists. Inclusion criteria for this study were a successful initial PTCA and post-PTCA recatheterization if a patient complained of ischemic symptoms possibly related to restenosis. RESULTS Of the 41 patients, 15 (36.6%) had restenoses at a total of 18 previous angioplasty sites. Patients with high total (potential for) hostility ratings were almost 2.5 times more likely to have restenosis than those with low total (potential for) hostility scores (95% confidence interval = 1.03 to 5.32). Logistic regression revealed that total (potential for) hostility scores predicted post-PTCA restenosis overall as well as when adjusted for gender and race. Total (potential for) hostility scores were also positively associated with the number of arteries restenosed (P = 0.01). CONCLUSIONS This is the first report of type A total (potential for) hostility behavior conferring an increased risk for restenosis after PTCA. Its modification may be effective in reducing recurrent cardiac events. A coronary-prone behavior modification program for patients with persistent, same-site restenosis after PTCA has been initiated.