Evidence of a Cellular Protective Effect by Antecedent Angina Independent of Collateral Flow Recruitment During Coronary Angioplasty in Humans

Abstract

The main aim of this study was to elucidate whether the beneficial effect of antecedent angina is a cellular protective effect or the result of an increase of collateral flow. Of 42 patients with angina who underwent percutaneous transluminal coronary angioplasty (PTCA) for proximal left anterior descending artery (LAD) stenosis, 22 had experienced antecedent anginal pain (AP) within 7 days prior to PTCA. ^99mTc-sestamibi was injected during balloon inflation, and quantitative analysis of ischemic severity during coronary occlusion was calculated (SS). An electrocardiogram was recorded during ballooning to calculate the sum of ST elevation (ΣST). ΣST was significantly reduced in patients with AP compared with patients without AP (1.88±0.89 mV vs 1.18±0.74 mV, p=0.0088); however, no difference was observed in defect severity. A close correlation was observed between SS and ΣST in both groups. The multivariate regression model demonstrated that both a large SS (p<0.0001) and the absence of preceding AP (p=0.001) were significantly related to the elevation of ΣST. Recent angina can render the myocardium more resistant to subsequent ischemia during angioplasty and is true preconditioning rather than simply an increase of flow. (Circ J 2002; 66: 741 - 745)