Upstream anticoagulation in patients with ST-segment elevation myocardial infarction: a systematic review and meta-analysis.

BACKGROUND AND AIM: Parenteral anticoagulation is recommended for all patients presenting with ST-segment elevation myocardial infarction (STEMI) during primary percutaneous coronary intervention (PPCI). Whether upstream anticoagulation improves clinical outcomes is not well established. We conducted a systematic review and meta-analysis of contemporary evidence on parenteral anticoagulation timing for STEMI patients. METHODS: We performed a systematic search of electronic databases (PubMed, CENTRAL, and Scopus) until December 2022. Studies were eligible if they (a) compared upstream anticoagulation with administration at the catheterization laboratory and (b) enrolled patients with STEMI undergoing PPCI. Efficacy outcomes included in-hospital or 30-day mortality, in-hospital cardiogenic shock (CS), and TIMI flow grade pre- and post-PPCI. Safety outcome was defined as in-hospital or 30-day major bleeding. RESULTS: Overall, seven studies were included (all observational), with a total of 69,403 patients. Upstream anticoagulation was associated with a significant reduction in the incidence of in-hospital or 30-day all-cause mortality (OR 0.61; 95% CI 0.45-0.81; p < 0.001) and in-hospital CS (OR 0.68; 95% CI 0.58-0.81; p < 0.001) and with an increase in spontaneous reperfusion (pre-PPCI TIMI > 0: OR 1.46; 95% CI 1.35-1.57; p < 0.001). Pretreatment was not associated with an increase in major bleeding (OR 1.02; 95% CI 0.70-1.48; p = 0.930). CONCLUSIONS: Upstream anticoagulation was associated with a significantly lower risk of 30-day all-cause mortality, incidence of in-hospital CS, and improved reperfusion of the infarct-related artery (IRA). These findings were not accompanied by an increased risk of major bleeding, suggesting an overall clinical benefit of early anticoagulation in STEMI. These results require confirmation in a dedicated randomized clinical trial.