Impact of NIRS-IVUS-identified lipid-rich plaques on microvascular resistance reserve after PCI
H Kusumoto, D Shishikura, K Sakaguchi, S Fujioka, K Tsuda, D Maeda, Y Yamauchi, Y Kanzaki, M Shiba, H MoritaAbstract
Background/Purpose
Coronary lipid-rich plaque (LRP) is likely to cause distal embolization during PCI, which is associated with microvascular injury. Microvascular resistance reserve (MRR) is a novel index of coronary microvascular function regardless of epicardial stenosis. This study assessed the impact of LRP identified by NIRS-IVUS on coronary microvascular function including MRR during PCI.
Methods
We retrospectively analyzed 100 patients who underwent NIRS-IVUS–guided PCI. Coronary physiological assessment using a pressure–temperature sensor guidewire was performed pre- and post PCI. Lesions were stratified into two groups with or without LRP (maxLCBI4mm ≥500) and physiological measurements were compared.
Results
In total, lesions with LRP were identified in 39 patients (39%). Baseline clinical characteristics were similar between two groups. Fractional flow reserve (FFR) and resting full-cycle ratio (RFR) improved in both groups, whereas MRR decreased significantly in LRP lesions (ΔMRR −1.49±0.46 vs −0.32±0.37, p=0.04). On multivariable logistic regression, maxLCBI4mm ≥500 emerged as an independent predictor of post-PCI coronary microvascular dysfunction defined by MRR (odds ratio 3.06, 95% confidence interval 1.01–9.29).
Conclusion
In lipid-rich lesions, MRR decreased during PCI despite of improvement in epicardial physiological indices, suggesting that MRR may be superior index to predict coronary microvascular dysfunction.