791-3 The Influence of Clinical Risk Factors on the Use of Angiography and Revascularization After Acute Myocardial Infarction

Abstract

After acute myocardial infarction (AMI). the American College of Cardiology and the American Heart Association recommend angiography in patients “if the prognosis is judged to be poor … and … outcome can be improved by urgent bypass surgery or coronary angioplasty (PTCA).” In 4823 consecutive survivors of AMI, we examined the relationship between both angiography (n = 2274) and revascularization (n = 692 for PTCA, n = 469 for bypass surgery) and 7 clinical variables that predict mortality (age, recurrent angina, ejection fraction, heart failure, use of thrombolytics, prior infarction, cardiogenic shock). Multivariate logistic regression revealed that except for recurrent angina, most factors predicting higher mortality were associated with a lower use of angiography (OR(95%CI) = 2.75 (2.39–3.17) for recurrent angina, 0.47 (0.43–0.51) for older age, 0.85 (0.74–0.97) for prior infarction, 0.50 (0.43–0.59) for no thrombolytic treatment, and 0.63 (0.55–0.73) for heart failure during hospitalization). A similar relationship was observed among patients who underwent PTCA (OR(95%CI) = 1.94 (1.53–2.47) for recurrent angina, 0.51 (0.40–0.65) for low ejection fraction, 0.72 (0.57–0.93) for no thrombolytic therapy and 0.74 (0.56–0.98) for history of prior infarction). In contrast, patients with unfavorable prognostic profiles were more likely to undergo coronary bypass surgery (OR(95%CI) = 1.66 (1.34–2.06) for recurrent angina, 1.28 (1.11–1.47) for older age, 2.24 (1.78–2.82) for heart failure, 1.46 (1.18–1.80) for prior infarction and 1.28 for no thrombolytic therapy). Angiography and PTCA are performed more often in patients who are at relatively low risk for subsequent mortality. Since there is currently no evidence of a survival advantage from PTCA, the risks of this procedure could be avoided in some patients by initially treating them conservatively and subsequently performing PTCA in only those patients whose symptoms are not controlled with medications alone.