PROGNOSIS OF PATIENTS WITH ANGINA OR SILE NT ISCHEMIA ON TC-99M MIBI SPECT

Introduction and objectives. Although different reports have compared the extent of the myocardial ischemia in patients with or without angi na during exercise test, there have been few publications which have s tudied their prognosis. The aim of this study is to analyze the progno stic value of the presence of angina during Tc-99m-MIBI SPECT in patie nts with proven coronary artery disease without previous myocardial in farction. Patients and methods. We studied 82 patients prospectively w ith at least one coronary stenosis > 70% and with reversible perfusion defects in Tc-99m-MIBI SPECT (long protocol). Twenty two of these pat ients had angina during exercise test. The extension of ischemia was q uantified on SPECT and the severity of coronary stenoses on coronary a ngiography. The mean follow-up period was 3.2 years. Results. The angi na patients showed a significantly lower coronary reserve (exercise du ration: 6.3 min vs 8 min; p = 0.03), a lower maximal O-2 consumption ( 5.8 METs vs 6.2 METs; p = 0.04), a higher rate of ST depression > 1 mm (64% vs 19%; p = 0.006) and a higher degree of ST depression (0.9 mm vs 0.4 mm; p = 0.01) than those patients without angina. There were no significant differences in the extent of ischemia in SPECT or in the angiographic severity of coronary disease between either groups. Durin g the follow-up period the presence of severe complications (myocardia l infarction or death) tended to be higher (27% vs 17%; NS) in patient s with angina and the indication of surgical revascularization was als o significantly higher (50% vs 17%; p = 0.002) in this group. Conclusi ons. Presence of angina during Tc-99m-MIBI SPECT portents a higher ris k of medium and long term complications, mainly due to surgical revasc ularization.