Pretreatment of patients with ST-segment elevation myocardial infarction with heparin: a systematic review and meta-analysis

Abstract

Background: Unfractionated heparin (UFH) is frequently administered before percutaneous coronary intervention (PCI) in patients with ST-segment elevation myocardial infarction (STEMI). However, current guidelines do not provide clear recommendations for UFH pretreatment before arrival at the coronary catheterisation laboratory. Methods: Between June and July 2023, we systematically searched PubMed, Embase and Cochrane databases for studies comparing UFH pretreatments in patients with STEMI. A random-effects meta-analysis and meta-regression analyses were performed. Results: Fourteen studies were included, of which four were randomised clinical trials (RCTs). A total of 76446 patients were included: 31238 in the pretreatment group and 39208 in the control group. Our meta-analysis revealed a lower all-cause mortality for the pretreatment strategy when compared with the control group, albeit with high heterogeneity (pooled odds ratio (OR) = 0.61, 95% confidence interval (CI) [0.49 - 0.76], P < 0.01; I2 = 77%); lower in-hospital cardiogenic shock (pooled OR = 0.68, 95% CI [0.58, 0.78], P < 0.21; I2 = 27%) and a higher rate of spontaneous reperfusion events (pooled OR = 1.68, 95% CI [1.47, 1.91], P < 0.01; I2 = 79%). In terms of major bleeding, the UFH pretreatment strategy further revealed a decreased rate of events (pooled OR = 0.85, 95% CI [0.73, 0.99], P = 0.40; I2 = 4%). Conclusions: Our study suggests that UFH pretreatment in patients with STEMI undergoing primary PCI was associated to reduced all-cause mortality, cardiogenic shock, enhancing reperfusion rates, whilst diminishing major bleeding events.