PROGNOSTIC VALUE OF PREDISCHARGE RADIONUCLIDE VENTRICULOGRAPHY AT REST AND EXERCISE AFTER ACUTE MYOCARDIAL-INFARCTION TREATED WITH THROMBOLYTIC THERAPY OR PRIMARY CORONARY ANGIOPLASTY

Background: Previous studies have demonstrated the prognostic value of radionuclide ventriculography at rest and exercise in patients post m yocardial infarction (MI). The number of studies in patients treated w ith modem reperfusion techniques, including thrombolysis or primary an gioplasty, however, is limited. Hypothesis: The aim of this study was to evaluate the prognostic significance of predischarge radionuclide v entriculography at rest and exercise in patients with acute MI treated with thrombolysis or primary angioplasty. Methods: A total of 272 con secutive patients with acute MI who were randomized to thrombolysis or primary coronary angioplasty underwent predischarge resting and exerc ise radionuclide ventriculography. Left ventricular ejection fraction at rest, decrease in ejection fraction during exercise > 5 units below the resting value, angina pectoris, ST-segment depression, and exerci se test ineligibility were related to subsequent cardiac events (cardi ac death, nonfatal reinfarction) during follow-up. Results: During a m ean follow-up of 30 +/- 10 months, cardiac death occurred in 11 (4%) p atients and nonfatal reinfarction in 14 (5%) patients. Resting left ve ntricular ejection fraction was the major risk factor for cardiac deat h. In patients with an ejection fraction < 40%, cardiac death occurred in 16% compared with 2% in those with an ejection fraction greater th an or equal to 40% (p = 0.0004). In addition, cardiac death tended to be higher in patients ineligible than in those eligible for exercise t esting (11 vs. 3%, p = 0.08). None of the other exercise variables (de crease in ejection fraction during exercise > 5 units below the restin g value, angina pectoris or ST-segment depression) were predictive for cardiac death, When all exercise test variables in each patient were combined and expressed as a risk score, a low risk (n = 185) and a hig her risk (n = 87) group of patients could be identified, with cardiac death occurring in 1 and 10%, respectively. As the predictive accuracy of a negative test was high, radionuclide ventriculography was of par ticular value in identifying patients at low risk for cardiac death. R adionuclide ventriculography was not able to predict recurrent nonfata l MI. Conclusion: In patients with MI treated with thrombolysis or pri mary angioplasty, radionuclide ventriculography may be helpful in iden tifying patients at low risk for subsequent cardiac death. In this res pect, left ventricular ejection fraction at rest was the major determi nant. Variables reflecting residual myocardial ischemia were of limite d prognostic value. Identification of a large number of patients at lo w risk allows selective use of medical resources during follow-up in t his subgroup and has significant implications for the cost effectivene ss of reperfusion therapies.