Abstract 3669: Relationship Between Coronary Collateral Circulation and Ischemic Preconditioning During Percutaneous Coronary Intervention
Background: Ischemic preconditioning (IP) is related to various factors, and the mechanism remains uncertain. We examined the hypothesis that repeated ischemia increases collateral flow and is related to the mechanism of ischemic preconditioning.
Methods: Fifty-two patients with stable effort angina who underwent percutaneous coronary intervention (PCI) were divided into 2 groups: IP(+) group (n= 22, ST-segment elevation in electrocardiogram was gradually decreased during repeated balloon inflations in the setting of PCI) and IP(−) group (n= 28, ST-segment elevation was gradually increased or did not change during PCI). The changes of QC/QN, which is the index of collateral flow, were determined by pressure wire and were compared between the 2 groups.
Results: Clinical characteristics and angiographic features were similar in the 2 groups. At the time of initial balloon occlusion, QC/QN were not different between the IP(+) and IP(−) groups (0.23 ± 0.04 vs. 0.25 ± 0.06). QC/QN were significantly decreased at the second time of balloon occlusion compared with the first time of balloon occlusion [IP(+), from 0.23 ± 0.04 to 0.20 ± 0.03, p <0.05; IP(−), 0.25 ± 0.06 to 0.20 ± 0.04, p <0.05], and these changes (0.03 ± 0.04 vs. 0.04 ± 0.05) were not significantly different between groups.
Conclusion: Intracoronary pressure measurements during PCI revealed that ischemic preconditioning during repeated balloon inflation is independent of collateral circulation.