[Long-term prognosis after myocardial infarction. Value of exercise test compared to clinical features and coronarography]

Abstract

The aim of this study was to identify the parameters of exercise stress testing with a predictive value of cardiac death after myocardial infarction and to determine their importance with respect to clinical and coronary angiographic data. Three hundred and three patients, average age 48.9 +/- 9.2 years, surviving primary myocardial infarction, underwent a symptoms-limited exercise stress test and coronary angiography four to seven weeks after infarction. The average follow-up period was 48 +/- 22 months. Eighteen patients (5.9%) were lost to follow-up. Global mortality was 11.6% (33/285) and cardiac mortality was 8.8% (25/285) including 14 sudden deaths (56%) and 17 deaths during the first three years of follow-up (68%). A univariable analysis identified the following parameters of exercise stress testing as predictive of cardiac mortality. The duration of exercise, the maximal rate-pressure product, inconclusive test, the maximal heart rate, and occurrence of supraventricular arrhythmias. Only the last two parameters remained significant after a discriminant analysis and their combination with clinical variables (age and ventricular fibrillation during the hospital phase) enabled accurate classification of 79% of patients, which was significantly better than when clinical features were used alone (p 0.01). On the other hand, adding the data of coronary angiography (number of diseases vessels, absence of an Ergometrine test) only moderately improved this score (82%, NS). This study suggests that the results of the post-infarction exercise stress test enables identification of patients with a low or, on the contrary, with a high risk of cardiac death. The prognostic value of this investigation is better than simple clinical evaluation, especially in stable or asymptomatic patients. In this selected group of patients, coronary angiography did not provide additional prognostic information.