THE DIFFERING PROGNOSTIC UTILITY OF EXERCISE RADIONUCLIDE VENTRICULOGRAPHY IN CORONARY-ARTERY DISEASE PATIENTS WITH AND WITHOUT PRIOR MYOCARDIAL-INFARCTION

Previous studies have documented the prognostic utility of left ventri cular ejection fraction response to exercise primarily in populations without prior myocardial infarction. We undertook a study to assess th e prognostic utility of exercise left ventricular ejection fraction an d segmental wall motion response during exercise radionuclide ventricu lography in coronary artery disease patients with and without prior my ocardial infarction. Methods. We examined the comparative prognostic u tility of left ventricular ejection fraction and segmental wall motion response during upright bicycle exercise radionuclide ventriculograph y in 419 coronary artery disease patients with (n=217) and without (n= 202) prior myocardial infarction using univariate and multivariate hie rarchical regression analyses. Results. During an average followup per iod of 61 months, 96 patients (23%) suffered cardiac events, including 55/217 (25%) of the patients with prior myocardial infarction and 41/ 200 (21%) of the patients without prior myocardial infarction (p=ns). Both cumulative Kaplan-Meier survival analyses and stepwise hierarchic al Cox survival analyses demonstrated that peak left ventricular eject ion fraction <55% was a significant predictor of cardiac events in pat ients without prior myocardial infarction (p=0.04), whereas an exercis e wall motion worsening score greater than or equal to 2 was a signifi cant predictor in patients with a prior myocardial infarction (p=0.000 1). Conclusions. The prognostic utility of exercise radionuclide ventr iculography variables differ according to the presence or absence of p rior myocardial infarction. Global function, assessed by peak left ven tricular ejection fraction, adds the greatest prognostic information i n patients without prior myocardial infarction, whereas regional funct ion, assessed by exercise wall motion worsening, is the best predictor among patients with prior myocardial infarction.