VALUE OF THE EARLY STRESS TEST DURING TRE ATMENT AFTER MYOCARDIAL-INFARCTION WITH Q-WAVE IN PATIENTS UNDER THE AGE OF 55 YEARS

We studied one hundred consecutive patients, under the age of 55 years (mean age. 45.6 years), with myocardial infarction and a Q wave, in o rder to assess the prognostic value of an early stress test. Thirty fi ve patients were excluded: 2 deaths, 21 revascularizations during the acute phase, 4 tests were performed without treatment, 6 tests were un able to be performed and 2 patients left hospital against medical advi ce. Sixty five patients [males, n = 60 (92.2 %), anterior infarction, n = 25 (38.5 %), thrombolysed n = 35 (53.8 %), intact left ventricular ejection fraction (mean : 54.7 %)] systematically underwent a stress test limited by symptoms, in hospital, on the tenth day of infarction, using an ergometric bicycle and under medical treatment [including be ta blockers n = 47 (72.2 %)] and cardiac catheterization. The test was considered positive when ii was accompanied by angina and/or ST depre ssion (n=19), negative in the absence of these criteria for a level of 120 watts (n=23), inadequate when the duration was less than 9 minute s and when the heart rate was less than or equal to 70 % of the theore tical maximal heart rate (n=11), doubtful when there was accentuation of ST elevation in the infarcted territory with mirror ST depression ( n=12). Only 30.7 % of patients had multi-vessel coronary lesions (two- and three-vessel disease). The mortality was 4.6 % with a mean follow -up of 27.4 months (range: 3-38). The sensitivity of the test for dete ction of multi-vessel disease was 62.5 %, the specificity was 65.3 %, the positive predictive value was 52.6 %, and the negative predictive value was 73.9 %. The sensitivity of this test, with beta-blocker trea tment, to predict coronary lesions or cardiac events, fell to 33.3 % a nd 37.5 %, respectively. The stress test during the post-infarction pe riod, with beta-blocker treatment, appears to be less sensitive for th e identification of multivessel disease and cardiac events :this treat ment should therefore be suspended before performing this test when al lowed by the patient's clinical state.