The role of exercise radionuclide angiocardiography in predicting future cardiac events in patients with acute myocardial infarction

Left ventricular ejection fraction (LVEF) during exercise radionuclide angi ocardiography is a useful prognostic index for patients with acute myocardi al infarction (AMI). However, most previous studies were performed before r eperfusion therapies (i.e., thrombolysis and coronary angioplasty) were wid ely used. Therefore, because reperfusion therapy has become a standard ther apeutic option, we reexamined the prognostic value of rest LVEF and exercis e LVEF determined by radionuclide angiocardiography in patients with AMI at the time of hospital discharge. Methods: The retrospective analysis includ ed 419 consecutive patients with AMI who underwent ergometric stress radion uclide angiocardiography before hospital discharge, 44 +/- 14 d after the o nset of AMI. Results: During a mean follow-up of 4.6 y, cardiac events occu rred in 101 (24.1%) patients. Cardiac events included recurrent MI (33 pati ents, 7.9%), unstable angina (49 patients, 11.7%), congestive heart failure (16 patients, 3.8%), and ventricular tachycardia (3 patients, 0.7%). The L VEF at peak exercise was significantly lower in the group with cardiac even ts (P = 0.0140). However, no significant difference was observed in the res t LVEF between patients with and without cardiac events. On the basis of mu ltivariate analysis using a Cox proportional hazards model, only peak LVEF (P = 0.0246) was found to be an independent predictor of cardiac events. In the patient subsets with a peak LVEF >50% or <50%, the event-free rate was 81.0% versus 62.4% (P = 0.0007), respectively. Regardless of the presence or absence of reperfusion therapy, the lower peak LVEF was associated with a decrease in the event-free survival rate. Conclusion: In the current repe rfusion era, the lower peak LVEF as measured by radionuclide angiocardiogra phy at the time of discharge is a useful predictor of subsequent cardiac ev ents in patients with AMI.