陳旧性心筋梗塞例での冠予備能による心筋 viability の評価

Abstract

We investigated the usefulness of the coronary flow reserve(CFR)for estimation of myocardial viability in patients with old myocardial infarction(MI). Twenty-three patients with old anterior MI, who had single vessel disease of the left anterior descending artery(LAD), enrolled in this study. They had undergone transluminal angioplasty and had no restenosis of the target lesioon on the follow-up coronary angiogra- phy. CFR was measured with a Doppler guidewire during the follow-up angiography in the LAD. Based on the CFR, these patients were divided into two groups : those who showed more than 2.0(Group H), and those who showed less than 2.0(Group L). The myocardial scintigraphy using thallium-201(Tl)and iodine-123-β-methyl-p-iodophenyl pentadecanoic acid(BMIPP)were examined 7±2 months after the MI onset. Based on the regional Tl and BMIPP uptake, the severity score(SS)was defined. The Tl/BMIPP discrepancies between SS on the early phase BMIPP and the delayed phase of Tl were studied. The former was higher than the latter. The SS of Tl and BMIPP, and the frequency of Tl/BMIPP discrepancies were compared between the two groups. The relationships between CFR and the SS were also studied. In Group H, both the SS of Tl and the SS of BMIPP were lower(Tl : P＜0.001 ; BMIPP : P＜0.001)than those in Group L. The frequency of the Tl/BMIPP discrepancy was higher(P＜0.001)than that in Group L. The relationship between CFR and the SS of Tl showed a statistically negative correlati on (early : r=0.64, p＜0.01 ; delayed : r=0.62,p ＜0.01). The relationship between CFR and the SS of BMIPP showed a statistically negative correlation(early : r=0.58, p＜0.01 ; delayed : r=0.52, p＜0.05), as well. The area of myocardium showing Tl/BMIPP discrepancy is viable. We concluded that CFR of infarct related coronary artery can reflect the regional Tl and BMIPP uptake and is useful for the estimation of myocardial viability in patients with old myocardial infarction.