Determinants of Slow Flow in Percutaneous Coronary Intervention to the Culprit Lesion of Non-ST Elevation Myocardial Infarction.

Abstract

Slow flow is a serious complication in percutaneous coronary intervention (PCI) and is associated with poor clinical outcomes. Our previous study revealed that the ratio of stent diameter to vessel diameter was the determinant of slow flow in intravascular ultrasound (IVUS)-guided PCI to the culprit lesion of ST elevation myocardial infarction (STEMI). The purpose of this study was to verify whether the ratio of stent diameter to vessel diameter is the determinant of slow flow in IVUS-guided PCI to the culprit lesion of non-STEMI (NSTEMI). We included 150 NSTEMI patients and divided into the slow flow group (n = 17) and the non-slow flow group (n = 133). The ratio of stent diameter to vessel diameter was significantly larger in the slow flow group (0.77 ± 0.11) than the non-slow flow group (0.71 ± 0.11) (P = 0.03). Multivariate logistic regression analysis revealed that the ratio of stent diameter to vessel diameter (per 0.1 increase: OR 2.06, 95% CI 1.23-3.46, P = 0.006) was the determinant of slow flow after controlling covariates. In conclusion, the ratio of stent diameter to vessel diameter was the determinant of slow flow in IVUS-guided PCI to the culprit lesion of NSTEMI. Unlike other parameters, the ratio of stent diameter to vessel diameter is the modifiable parameters. We may consider the modest stent expansion strategy rather than the aggressive stent expansion strategy in IVUS-guided PCI to the culprit lesion of NSTEMI.