No-Reflow Phenomenon After Acute Myocardial Infarction Is Associated With Reduced Clot Permeability and Susceptibility to Lysis

Abstract

Objective— We assessed the relationship between fibrin clot properties and the no-reflow phenomenon after primary coronary intervention (PCI). Methods and Results— Epicardial blood flow was assessed by TIMI scale and corrected TIMI frame count (cTFC), and perfusion by TIMI Myocardial Perfusion Grade (TMPG) after PCI during ST-segment elevation myocardial infarction (STEMI). Fibrin clot permeability (K _s ) and susceptibility to lysis in assays using exogenous thrombin (t _50% ) and without thrombin (t _TF ) were determined in 30 no-reflow patients (TIMI ≤2) and in 31 controls (TIMI-3) after uneventful 6 to 14 months from PCI. Patients with TIMI ≤2 had lower K _s by 18% ( P 50% ( P TF ( P s ( r =−0.56, P 50% ( r =0.49, P TF ( r =0.54, P s increased in a stepwise fashion with TIMI flow ( P P P P s and fibrinogen were independent predictors of cTFC ( P P P Conclusions— Survivors of myocardial infarction with a history of the no-reflow after PCI are characterized with more compact fibrin network and its resistance to lysis.