Severity and extent of perfusion defects provoked by transient coronary occlusion compared with myocardial damage observed after infarction

A peripheral perfusion tracer injection at the time of coronary occlusion during percutaneous transluminal coronary angioplasty (PTCA) may delineate the myocardial 'area at risk' related to a given artery. To evaluate the location, size and severity of the corresponding scintigraphic defects, we conducted a prospective study of 36 patients who received a Tc-99(m)-sestamibi injection during single-vessel coronary angioplasty (PTCA=18 LAD, 16 RCA and 2 LCX) followed by SPET. For comparison, a reference group of 36 successive patients examined during the early phase of myocardial infarction (MI), matched for the same vascular territories (18 anterior, 16 inferior and 2 lateral), were analysed in the same way after standard stress/reinjection Tl-201 SPET. The imaging characteristics of both groups showed excellent agreement as well degree of uptake defects, in terms of topography and extent. A defect index, taking into account both size and severity, was in the same range for PTCA and MI patients (mean+/-standard deviation): for LAD vs anterior = 28.4+/-13.5% (PTCA), 27.1+/-12.2% (MI-stress) and 24.2+/-10.0% (MI-reinjection); for RCA vs inferior = 15.5+/-10.2% (PTCA), 14.7+/-9.7% (MI-stress) and 13.2+/-8.2% (MI-reinjection). Sectoral correlations between PTCA and MI groups were also highly significant. ((C) 2000 Lippincott Williams & Wilkins).