The No-Reflow Phenomenon: Clinical and Angiographic Correlates

No-reflow occurring during PCI has been associated with poor outcomes. The objectives of this study were to evaluate the incidence of no-reflow as independent predictor of adverse events and to assess whether baseline pre-procedural treatment options may affect clinical outcomes. Data were derived from the ISACS-TC (NCT01218776) registry, a prospective survey of patients presenting with ACS over a 5-year period. Data were prospectively collected from 5997 patients undergoing PCI, identifying those with no-reflow, and analyzed their treatments and outcomes. No-reflow was defined as post-PCI TIMI flow grade 0-1, in the absence of post-procedural significant (≥25%) residual stenosis, abrupt vessel closure, dissection, perforation, thrombus of the original target lesion, or epicardial spasm. The outcome measure was in-hospital mortality. No-reflow was identified in 128 (2.1%) patients. On multivariate analysis, patients with no-reflow were more likely to be older (OR:1.20, 95%CI:1.01–1.44) and to be admitted with a diagnosis of ST-elevation myocardial infarction (OR:2.96, 95%CI:1.85–4.72). No-reflow was highly predictive of in-hospital mortality (17.2% vs. 4.2%, P<0.001) and remained a significant independent predictor of death after adjustment for demographic and clinical variables (OR:4.60,95%CI:2.61–8.09). Multivariable regression analysis was also performed to identify independent relationship between pre-procedural treatment regimens, angiographic characteristics and no-reflow phenomenon. Administration of pre-procedural unfractioned heparin, showed a strong inverse predictive value in terms of post-PCI TIMI flow and no-reflow phenomenon (OR: 0.65, 95%CI:0.43–0.99). Similarly, a 600-mg loading dose of clopidogrel showed a trend associated with a reduction in the likehood of no-reflow (OR:0.61,95%CI:0.37–1.00). Angiographic characteristics associated with no-reflow phenomenon were stenosis≥50% of the right coronary artery, presence of multivessel coronary disease and pre-procedural TIMI blood flow grade 0-1. In conclusion, no-reflow during PCI is a strong independent predictor of mortality. Pre-procedural administration of 600-mg loading dose of clopidogrel and/or unfractioned heparin is associated with reduced incidence of no-reflow.