Risk Factors of No-Reflow Phenomenon after Primary Percutaneous Coronary Intervention with Stent Implantation

BACKGROUND AND OBJECTIVES: No-reflow is an important phenomenon for limiting the prognosis of patients following primary percutaneous coronary intervention (PCI) for acute myocardial infarction (AMI). Coronary stenting is the current standard procedure for primary PCI in AMI. However, stenting is suspected to cause more microembolization, and no-reflow phenomenon. This study was performed to elucidate the risk factors for the no-reflow phenomenon following primary PCI with stenting, in patients with AMI.

SUBJCETS AND METHODS: The clinical, angiographic and procedure related parameters were reviewed in patients with AMI that had undergone primary PCI, with stent implantation, within 12 h of the onset of chest pain, at Seoul National University Hospital, Yonsei University Hospital Cardiovascular Center and Chungbuk National University Hospital (n=183).

RESULTS: 29 patients (16%) showed no-reflow phenomenon (final TIMI flow grade less than 3). Conventional risk factors for coronary artery disease were not significant risk factors for the no-reflow phenomenon. In a univariate analysis, a high initial CK-MB level (>50 IU) (8.45% vs. 21.9%, p=0.04), low left ventricular ejection fraction (LV EF) (<50%) (19% vs. 5%, p=0.03) and long pre-dilatation balloon inflation time (>30 sec) (31% vs. 15%, p=0.04) were significant risk factors of the no-reflow phenomenon. A low LV EF and long pre-dilatation balloon inflation time were significant risk factors in a multivariate analysis.

CONCLUSION: LV dysfunction at presentation and a long pre-dilatation balloon inflation time were independent risk factors for the no-reflow phenomenon following primary PCI with stenting for AMI. Preventive measures against the no-reflow phenomenon should be considered in patients with these risk factors.