Risk stratification after percutaneous transluminal coronary angioplasty

Abstract

Approximately 20-30% of patients who undergo elective percutaneous transluminal coronary angioplasty (PTCA) require a second angioplasty within 12 months. A significant proportion of patients develop clinical cardiac events during the first year following the initial procedure. The present investigation was undertaken to establish a statistical model for predicting such events. The study group consisted of 100 patients who underwent elective PTCA at the University of Alberta Hospital. All patients were prescribed nifedipine (10 mg tid) and aspirin (325 mg daily) in addition to other medications determined by the attending cardiologist. The patients were reviewed 10 weeks after the procedure and again at the end of 1 year. The follow-up was completed on 96 patients. Within the first year, forty-five experienced cardiac events (1 death, 5 myocardial infarctions, 4 bypass surgeries, 22 repeat PTCAs). These events occurred in 29 patients. An additional 16 patients experienced significant anginal symptoms. A statistical model based upon the patients' perception of symptoms immediately after the procedure, history of hypertension, vessel subjected to PTCA, ejection fraction pre-PTCA, and occurrence of intimal dissection during PTCA was used to identify patients likely to develop cardiac events. Overall, the model classified 72% of the patients (with and without events). Such a statistical model could be used to identify patients who should be subjected to an enhanced degree of cardiologic surveillance in a rehabilitation program.