EVALUATION OF CHANGES IN MYOCARDIAL PERFUSION AND FUNCTION ON EXERCISE IN PATIENTS WITH CORONARY-ARTERY DISEASE BY GATED MIBI SCINTIGRAPHY

Objective-To investigate the ability of gated methoxy-isobutylisonitri le (MIBI) scintigraphy to measure changes in myocardial function as we ll as perfusion with exercise. Setting-Regional cardiothoracic centre. Patients-43 presenting with chest pain, 28 with coronary artery disea se on angiography, and 15 with normal coronary arteriograms. Results-G ated perfusion images showed an improvement in detecting regions with stenosed arteries compared with non-gated images (38/55 v 31/55, p les s-than-or-equal-to 0.01)). Functional analysis showed an increase in f ractional shortening of 4.11% in subjects with normal coronary arterie s, whereas in those with coronary disease a fall of 0.57% was found (p less-than-or-equal-to 0.01). Both perfusion and function imaging show ed an improved sensitivity compared with standard exercise testing (p less-than-or-equal-to 0.01). When both function and perfusion imaging were analysed all patients with coronary disease were detected. There was agreement in abnormal regions in 33/55 territories supplied by a s tenosed artery. Combined perfusion and function detected 49/55 (89%) o f abnormal regions, thus improving the overall sensitivity from 38/55 (69%) by perfusion imaging alone (p less-than-or-equal-to 0.01). Concl usions-Gated methoxy-isobutylisonitrile scintigraphy can successfully evaluate perfusion and function on exercise, so improving the diagnost ic usefulness of this agent.