Point-of-care biomarkers of thrombotic status predict spontaneous reperfusion in ST-segment elevation MI and clinical outcomes

Abstract

Abstract Background Spontaneous reperfusion, seen in ∼20% of patients with ST-segment elevation myocardial infarction (STEMI), manifests as normal epicardial flow in the infarct-related artery (IRA), with or without ST-segment resolution, before percutaneous coronary intervention (PCI). The drivers mediating this are unknown. Purpose We aimed to assess whether the thrombotic profile of patients with and without spontaneous reperfusion differed significantly, and whether such patients had better outcomes. Methods We performed a prospective, observational study in consecutive patients presenting with STEMI. Blood samples were taken from a 6 Fr arterial sheath immediately before emergency angiography, before PPCI, after dual antiplatelet therapy loading, but before the administration of heparin or other anticoagulant. Blood samples were tested using a point-of-care global test of thrombotic status, measuring occlusion (OT) and endogenous fibrinolysis (LT) times. Spontaneous reperfusion was defined as IRA TIMI III flow pre-PCI. Patients were followed for major cardiovascular events (MACE; death, myocardial infarction, stroke). Results Spontaneous reperfusion was associated with longer OT (435s vs. 366s, p<0.001) and shorter LT (1257s vs. 1616s, p<0.001), lower troponin and better LV function. LT was superior to OT for predicting spontaneous reperfusion (AUC for LT: 0.707, 95% CI 0.661-0.753; AUC for OT: 0.629, 95% CI 0.581-0.677). Amongst patients with spontaneous reperfusion, those with complete, versus partial ST-segment resolution, had longer OT (p=0.002) and shorter LT (p<0.001). Spontaneous reperfusion was unrelated to clinical characteristics or pain-to-angiography times. Over 4-years, patients with spontaneous reperfusion experienced fewer MACE than those without (4.1% vs. 10.6%, p=0.013), especially in those with both spontaneous reperfusion and complete ST-segment resolution (1.5% vs. 10.1%, p=0.029). Conclusions We demonstrate a novel haematological signature in STEMI patients with spontaneous reperfusion, namely reduced platelet reactivity and faster endogenous fibrinolysis, relating to smaller infarcts and improved survival. This indicates a role for modulating thrombotic status early following STEMI-onset, to facilitate spontaneous reperfusion and improve outcomes.Visual abstractThrombotic profile predicts outcome