Predictors of no-reflow phenomenon following percutaneous coronary intervention for ST-segment elevation myocardial infarction.

OBJECTIVES: No reflow during percutaneous coronary intervention (PCI) is a complex issue with serious outcomes. Multiple studies have studied predictors of no-reflow during primary PCI, but data on patients with the late presentation is sparse, which constitutes the majority of patients in peripheral centers. This study aimed to determine predictors of no-reflow during PCI in patients with ST-segment elevation myocardial infarction (STEMI) in 7 days.

METHODS: It was a single-center prospective case-control study performed at a tertiary care center and included 958 patients with STEMI who underwent PCI within 7 days of symptom onset. Baseline and angiographic data of patients undergoing PCI were recorded and patients divided into reflow and no-reflow group.

RESULTS: Of 958 who underwent PCI, 182 (18.9%) showed no-reflow by myocardial blush grade (MBG)<2. No-reflow group had a higher mean age (66.46±10.71 vs. 61.36±9.94 years), lower systolic blood pressure (SBP) on admission (100.61±26.66 vs. 112.23±24.35, P<0.0001), a higher level of peak Troponin I level (9.37±2.81 vs. 7.66±3.11ng/dL, P<0.0001), low left ventricular ejection fraction (36.71±3.89 vs. 39.58±4.28% respectively P<0.0001). Among angiographic data and procedural features, multivariable logistic regression analysis identified that advanced age, reperfusion time>6hours, SBP<100mmHg on admission, functional status of Killip class for heart failure≥3, lower EF (≤35%), low initial myocardial blush grade (≤1) before PCI, long target lesion length, larger reference diameter of vessel (>3.5mm) and high thrombus burden on angiography were found to be independent predictors of no-reflow (P<0.05).

CONCLUSION: No-reflow phenomenon after PCI for STEMI is complex and multifactorial and can be identified by simple clinical, angiographic, and procedural features. Preprocedural characters of the lesion and early perfusion decides the fate of the outcome.