Spontaneous Coronary Reperfusion in STEMI After Pre-Hospital Loading Dose of Triple Antithrombotic Therapy

To evaluate the incidence and prognosis of spontaneous coronary reperfusion in STEMI using pre-hospital loading dose of P2Y12 inhibitors.

This prospective bi-centric study included STEMI patients who referred for primary PCI from June 1, to November 1, 2022. All patients received before hospital admission loading dose of aspirin, heparin and P2Y₁₂ inhibitor. The primary outcome was incidence of spontaneous coronary reperfusion (TIMI 3 flow) before primary PCI. Major in-hospital and 1-year events were secondary outcomes.

Within the study period, 263 patients were admitted with ongoing STEMI and 49 of them (18.6%) had spontaneous coronary reperfusion with no significant difference between loading dose of ticagrelor (n = 226; 85.9%) or clopidogrel (n = 27, 10.3%) and TIMI 3 flow (n = 41; 18.1% vs. n = 7; 25.9%, p = 0.53; respectively). Peak of T-hs troponin (p < 0.001) and CRP (p = 0.03) were significantly lower in the TIMI 3 group. In multivariate analysis, out-of- hospital cardiac arrests were observed twice as often in the TIMI 3 group (16.33 vs. 7.01%; p = 0.044). There was no significant difference between the two groups regarding major in-hospital (p = 0.69) or 1-year major events (p = 0.20).

Spontaneous reperfusion at admission was observed in about 20% of STEMI patients who received a pre-hospital loading dose of antithrombotic therapy including P2Y₁₂ inhibitors, and was associated with markers of decrease of infarct size. The significant increase of pre-admission cardiac arrests observed in the TIMI 3 group could be specifically explored as it might be a concern regarding future pre-hospital reperfusion therapy strategies.