RESUMO
PURPOSE: To evaluate safety and usefulness of dipyridamole-radionuclide ventriculography (D-RVG), soon after acute myocardial infarction (MI), in the prediction of future cardiac events. Traditionally performed tests were also compared. PATIENTS AND METHODS: Forty-one patients (4 females) with recent MI underwent rest and dipyridamole (0.58 mg/kg of body weight) radionuclide ventriculography. The criteria for a positive test for ischemia was failure to increase left ventricular ejection fraction in 0.05 from baseline value. All patients had also coronary angiography and 36 patients underwent thallium-201 scintigraphy for comparison. The mean follow-up was 16 +/- 3 months. The following findings were considered future for events: cardiac death, reinfarction, significant angina or heart failure. RESULTS: During the follow-up 18 of the 20 patients who had cardiac events had shown positive dipyridamole-RVG, as opposed to 5 of 21 event-free patients (p less than 0.01). The ventriculographic criteria for a positive test and dipyridamole left ventricular ejection fraction were the strongest predictors of those medical events (p less than 0.01 and p less than 0.001). Among the 36 patients who had thallium-201 imaging, 16 subsequently had cardiac events and the scans were positive in 82% (p less than 0.01). Twelve (29%) patients experienced reactions during dipyridamole infusion although no fatal complications were noted. CONCLUSION: Dipyridamole-RVG is relatively safe and a sensitive predictor of future cardiac events soon after acute MI, although additional experience is required before this new technique should be routinely recommended as an alternative approach.
