Perfusion-metabolic mismatch in myocardial scintigraphy in patients with vasospastic angina: what does it mean clinically?

Abstract

Abstract Background It has been reported that perfusion-metabolic mismatch (PMM) in thallium-201 (Tl) and 123I-βmethyl-p-iodophenyl-pentadecanoic acid (BMIPP) shows important information regarding myocardial ischemia in the clinical setting. Such findings have been frequently obtained, even in patients with vasospastic angina (VSA). However, it has not been fully clarified what such findings mean clinically in patients with VSA. There, we investigated the frequency of PMM in patients with VSA as well as clinical characteristics of patients with VSA who have PMM. Methods Seventy-eight patients (mean age: 70 yrs, 29 men and 49 women) were diagnosed with VSA by coronary angiography and spasm-provocation test (SPT). We defined VSA as the presence of more than 90% narrowing of the epicardial coronary artery on angiograms, accompanied by the usual chest symptoms and/or ischemic ST-T changes on electrocardiogram. On SPT, multi-vessel spasm was defined as the presence of spasm on ≥ two major coronary arteries. Dual myocardial scintigraphy with Tl and BMIPP was performed, and the presence of PMM was defined as the summed rest score (SRS) in BMIPP scintigraphy ≥4 and difference in SRS in BMIPP and Tl-201 ≥4. Patients were divided into two groups according to the presence of PMM: Group I (+PMM, n=30) and Group II (−PMM, n=48). Each patient with VSA was assessed for conventional coronary risk factors, numbers of angina attacks per month, and taking vasodilators. Results Age, gender distribution, and conventional risk factors were not different between the groups. The median number of angina attacks was higher in the Group I than in the Group II (Group I: 4.5 vs. Group II: 0.1, p<0.01), and fewer patients were taking vasodilators in Group I (Group I: 1.1±1.0 vs. Group II: 1.5±1.1, p<0.05). On SPT, the presence of multi-vessels spasm was significantly higher in Group I (76%) than Group II (44%, p<0.05). Logistic regression analysis showed that the presence of multi-vessels spasm (p<0.05) and taking a smaller amount of vasodilators (p<0.05) were associated with PMM. Conclusions These findings suggest that PMM in Tl and BMIPP scintigraphy are associated with multi-vessels spasm and a smaller amount of vasodilator medication. This imaging data may provide important information regarding activity of VSA and sufficient medication. Funding Acknowledgement Type of funding source: None