Long-term (10 years) prognostic value of a normal thallium-201 myocardial exercise scintigraphy in patients with coronary artery disease documented by angiography

In order to assess the prognostic significance of normal exercisethallium-210 myocardial scintigraphy in patients with documentedcoronary artery disease, we studied the incidence of cardiacdeath and non-fatal myocardial infarction in 69 symptomaticpatients without prior Q wave myocardial infarction, who demonstratedone or more significant coronary lesions (stenosis 70%) on anangiogram performed within 3 months of scintigraphy (Group 1).These patients were compared to a second group of 136 patientswith an abnormal exercise scintigram, defined by the presenceof reversible defect(s) and angiographically proven coronaryartery disease (Group 2), and to a third group of 102 patientswith normal exercise scintigraphy without significant coronarylesions (stenosis 30%) or with normal coronary angiography (Group3). In contrast to coronary lesions observed in Group 2, patientsin Group I presented more frequently with single- vessel disease(83% vs 35%, P>0·0001) and with more distal lesions(55% vs 23%, P>0·0001). Over a mean follow-up periodof 8·6 years, one fatal and eight non-fatal cases ofmyocardial infarction were observed in Group 1. The majorityof patients in Group 1 were treated medically: only 24 (35%)underwent myocardial revascularization, usually by coronaryangioplasty. There was no significant difference in the incidenceof combined major cardiac events (cardiac death, non-fatal myocardialinfarction) in patients with normal exercise scintigraphy, withor without documented coronary artery disease (Groups 1 and3), while the incidence was higher in Group 2. However, whilethe mortality remained very low in Group 1, the incidence ofnon-fatal myocardial infraction was not different from thatof Group 2, where most patients underwent revascularizationprocedures. In conclusion, patients with coronary artery disease and a normalexercise thallium-201 myocardial scintigram usually have mildcoronary lesions (single-vessel disease, distal location) andgood long-term prognosis, with a low incidence of cardiac death.