RISK STRATIFICATION FOR LONG-TERM OUTCOME AFTER ELECTIVE CORONARY ANGIOPLASTY - A MULTIVARIATE-ANALYSIS OF 5,000 PATIENTS

Objectives. We attempted to develop a statistical model to facilitate risk stratification for long-term outcome after elective coronary angioplasty. Background. Our understanding of factors related to long term outcome after coronary angioplasty is limited. Adequate assess ment of risk indexes could potentially lead to more appropriate use of percutaneous revascularization. Methods. We studied 5,000 consecutive patients and assessed 19 clinical and anatomic variables as predictors of long term event free survival. Events were defined as death of any cause, myocardial infarction, bypass surgery or repeat percutaneous transluminal coronary angioplasty. Cox proportional hazards models were used to develop an equation for predicting event free survival in a subset of 4,000 patients. The equation was validated with the remaining 1,000 patients. Variables that were significantly associated with an adverse outcome in the multivariate model included age >60 years, extent of disease, Canadian Cardiovascular Society functional class, previous coronary angio plasty, male gender, history of diabetes mellitus, history of hypertension and history of congestive heart failure. Results. The statistical model was used to develop a simplified scoring system, and the patients were assigned to three risk subgroups. Event-free survival curves for the three groups were significantly different (p = 0.0001). High risk patients had worse outcomes for each of the end points compared with low and moderate risk patients (p < 0.02). Conclusions. We demonstrated that clinical and anatomic variables can be used to risk-stratify long term outcome after angioplasty, that a simplified scoring system can be used for risk stratification and that high risk patients have a low event-free survival.