Heparin pretreatment for STEMI primary angioplasty: a meta-analysis

The early administration of unfractionated heparin (UFH) for ST-segment elevation myocardial infarction (STEMI) is still a matter of discussion, and clinical practice guidelines leave the timing of administration prior to angioplasty at the physician's discretion.

We conducted a systematic search across PubMed/Cochrane databases for studies comparing pre-treatment with UFH with a comparative untreated group (non-UFH) of patients with STEMI undergoing primary angioplasty and including TIMI flow and 30-day mortality targets from June 2024 through September 2024. We conducted a randomized meta-analysis and assessed the risk of publication bias to detect asymmetry in the included studies.

We included a total of 7 studies published from 2002 through 2022 (6 retrospective trials and 1 substudy of a randomized trial) for a total of 36 831 patients: 17 751 in the UFH pre-treatment group and 19 080 in the non-UFH control group. A total of 6202 patients (31.6%) on UFH had TIMI grade-II/III flow vs 5106 (23.0%) on non-NFH while 490 (3.9%) on UFH died within 30 days vs 673 (5.1%) on non-NFH. Meta-analysis demonstrated a higher probability of TIMI grade-II/III flow (HR, 1.35; 95%CI, 1.25-1.45; P < .0001) and a lower 30-day mortality rate in patients on UFH pretreatment (HR, 0.80; 95%CI, 0.72-0.90; P = .0002), with no differences being reported in bleeding complications (HR, 0.87; 95%CI, 0.72-1.05; P = .150).

Meta-analysis of studies shows that pretreatment with UFH in STEMI patients undergoing primary angioplasty is associated with a higher probability of TIMI grade-II/III flow and a lower risk of early mortality. Meta-analysis registered in PROSPERO (CRD420250655362).