Background: The phenomenon of no-reflow is defined as the occurrence of areas with very low tissue flow after the target vessel has reopened. Current knowledge suggests that the no-reflow phenomenon is caused by the damage to microvascular integrity established both during ischemia and during reperfusion. D-dimer is the end product of fibrin degradation by plasmin, as plasma concentrations increase in people with persistent or recent thrombosis. Its levels reflect the rate of fibrin turnover and give an indirect estimate of the size of the coagulant mass available for fibrinolysis and the severity of the hypercoagulable condition.
Objective: To investigate the Clinical and laboratory predictors of no-reflowon admission afterprimary percutaneous coronary intervention (PCI) in ST-elevation myocardial infarction (STEMI) patients.
Patients and methods: A prospective single group observational study.A total of 100 patients presented with STEMI and eligible for primary PCI to the cardiology department in Ain Shams University hospital.
Results: Coronary angiography showed that (74%) had normal flow while (26%) showed no re-flow. Renal impairment, DM and delayed reperfusion (> 4 hr)  were significantly associated with no reflow(P-values = 0.018,0.023,0.005) respectively. ROC curve showed that the best cut off point for D-dimer to predict cases with no reflow was found ≥ 560 with sensitivity of 96.15%, specificity of 79.73% and area under curve (AUC) of 86.5% where as the best cut off point for CRP  was > 41 with sensitivity of 76.92%, specificity of 64.86% and area under curve (AUC) of 69.8.
Conclusion: Assessment ofD-dimer and CRP levels on admission in STEMI patients might independently predicts no-reflow after primary PCI.