The no-reflow phenomenon in the young and in the elderly.

Background: 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.

Methods: Data were derived from the ISACS-TC registry (NCT01218776) from October 2010 to January 2015. No-reflow was defined as post-PCI TIMI flow grades 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.

Results: No-reflow was identified in 128 of 5997 patients who have undergone PCI (2.1%). On multivariate analysis, patients with no-reflow were more likely to be older (OR: 1.20, 95% CI: 1.01-1.44), to have a history of hypercholesterolemia (OR: 1.95, 95% CI: 1.31-2.91) and to be admitted with a diagnosis of STEMI (OR: 2.96, 95% CI: 1.85-4.72). Angiographic characteristics associated with no-reflow phenomenon were: stenosis ≥50% of the right coronary artery, presence of multivessel disease and pre-procedural TIMI blood flow grades 0-1. No-reflow was highly predictive of in-hospital mortality (17.2% vs. 4.2%; adjusted OR: 4.60, 95% CI: 2.61-8.09). Administration of pre-procedural unfractioned heparin or 600mg clopidogrel loading dose was associated with less incidence of no-reflow (OR: 0.65, 95% CI: 0.43-0.99 and 0.61, 95% CI: 0.37-1.00, respectively). Aspirin, enoxaparin, and 300mg clopidogrel loading dose, did not significantly impact the occurrence of the no-reflow.

Conclusions: We found that pre-procedural administration of 600mg loading dose of clopidogrel and/or unfractioned heparin is associated with reduced incidence of no-reflow.