PROGNOSTIC VALUE OF THE DIPYRIDAMOLE ECHOCARDIOGRAPHY TEST PERFORMED EARLY AFTER AORTOCORONARY BYPASS-SURGERY

It has been demonstrated that high dose (up to 0.84 mg/kg over 10 min) dipyridamole echocardiography stress testing is feasible even in the first few hours after coronary artery bypass graft surgery and can be used to assess the beneficial physiological effects of coronary revascularization as well as graft patency. The aim of this study was to assess the role of dipyridamole echocardiography testing performed shortly after myocardial revascularization in the stratification of prognosis during follow-up. We studied 49 consecutive patients (45 males and 4 females; mean age 56 +/-8 years) referred to our institute for elective myocardial revascularization. Six patients had single, 14 double, and 29 triple vessel disease. Forty-two left internal mammary artery grafts, 16 sequential venous grafts, and 45 single venous grafts were performed. All patients were submitted to dipyridamole echocardiography testing before (range 1-3 days) and shortly after (range 5-7 days) myocardial revascularization, always with the patients off antianginal medication. An arbitrary wall-motion score grading from 0 to 3 (normal, hypokinesia, akinesia, and dyskinesia) was applied to the seven regions into which the left ventricle was divided. Before surgery 48 patients showed wall-motion abnormalities during the test (47 patients also presented ECG changes). Angina occurred in 48 patients. One patient had ischemic ECG changes and angina. The mean wall-motion score was 3.11 per patient before and 6.5 per patient after the test (P < 0.001). During the test performed after myocardial revascularization, two patients showed wall-motion abnormalities, angina, and ECG ischemic changes; one patient showed wall-motion abnormalities and angina; two patients presented only ECG ischemic changes; one patient showed wall-motion abnormalities and angina; and two patients showed ischemic changes. The mean postsurgical wall-motion score was 2.5 per patient before and 2.8 per patient after the test (P = NS). Of the five patients with a positive test for echocardiographic and/or ECG criteria, five suffered events during a 1-year follow-up (two developed Q waves and resting wall-motion abnormalities; three had recurrence of angina); of the remaining 43 patients with a negative test for echocardiographic and ECG criteria, only two developed angina during follow -up. The incidence of postsurgical events was 100% in patients with a positive and 5% in patients with a negative dipyridamole echocardiography test early after myocardial revascularization (P < 0.001). In conclusion, our data demonstrate that dipyridamole echocardiography stress testing is a suitable method in the early assessment of myocardial revascularization at a time when other exercise-dependent methods are not feasible, and that a positive test in the early days after surgery indicates patients with a high risk of later developing ischemic events.