Strategies for prognostic assessment of uncomplicated first myocardial infarction: 5-year follow-up study

Abstract

Our aim was to use noninvasive studies early after infarction to assess medium-term prognosis in patients with a first uncomplicated myocardial infarction. Although the use of early postinfarction assessment to gauge short-term prognosis in myocardial infarction is well established, there have been few comprehensive evaluations of noninvasive methods for assessing medium- and long-term prognosis. We prospectively studied 115 consecutive patients < 65 years old with a first acute uncomplicated myocardial infarction to evaluate the prognostic role of predischarge cardiac studies. These included submaximal exercise testing, thallium-201 scintigraphy, radionuclide exercise ventriculography, two-dimensional echocardiography, ambulatory electrocardiographic (Holter) monitoring and cardiac catheterization. All patients without complications were followed up > or = 5 years. During the follow-up period, 78 patients (68%) developed complications, which were severe in 37 (32%). Exercise thallium-201 scintigraphy yielded the highest percentage (77%) for correctly classified patients. It also had the highest predictive value for complications (97%) and severe complications (92%) when it was used in association with exercise testing and radionuclide ventriculography. The addition of cardiac catheterization did not improve on the predictive power of noninvasive studies. Four decision trees (exercise testing + echocardiography, exercise testing + radionuclide ventriculography, thallium-201 + echocardiography, thallium-201 + radionuclide ventriculography) allowed stratification of all patients in a high, intermediate or low risk category. The combination of thallium-201 scintigraphy and radionuclide ventriculography yielded the best results (90% predictive value for complications if the outcome of both tests was positive), but there were no significant differences with the other models. Any combination of a test detecting residual ischemia or functional capacity, or both (exercise testing or thallium-201 scintigraphy), and a test assessing ventricular function (echocardiography or radionuclide ventriculography) results in useful prognostic information in patients with an uncomplicated first acute myocardial infarction.