Single Bolus r-SAK Before Primary PCI for ST-Segment-Elevation Myocardial Infarction.

Background: It is uncertain whether adjunctive thrombolysis is beneficial for patients with ST-segment-elevation myocardial infarction undergoing percutaneous coronary intervention (PCI) within 120 minutes of presentation. This study was to determine whether in patients presenting with ST-segment-elevation myocardial infarction a single bolus recombinant staphylokinase (r-SAK) before timely PCI leads to improved patency of the infarct-related artery and reduces the infarct size.

Methods: This is an open-label, prospective, multicenter, randomized study. We enrolled patients aged 18 to 75 years who were within 12 hours of symptom onset of ST-segment-elevation myocardial infarction and expected to undergo PCI within 120 minutes. Patients were administered loading doses of aspirin and ticagrelor and intravenous heparin and were randomized to receive 5 mg bolus of r-SAK or normal saline intravenously before PCI. The primary end point was Thrombolysis in Myocardial Infarction flow grade 2 to 3 or grade 3 in the infarct-related artery 60 minutes after thrombolysis. The infarct size was detected by cardiac magnetic resonance 5 days after randomization. The safety end point was major bleeding (Bleeding Academic Research Consortium ≥3) during 30-day follow-up.

Results: A total of 283 patients were screened from 8 centers and 200 were randomized (median age, 58.5 years; 14% female). The median symptom to thrombolysis time was 252.5 (interquartile range, 142.8-423.8) minutes and thrombolysis to coronary arteriography was 50.0 (interquartile range, 37.0-66.0) minutes. Patients randomized to r-SAK compared with normal saline more often had Thrombolysis in Myocardial Infarction flow grade 2 to 3 (69.0% versus 29.0%; <0.001) and Thrombolysis in Myocardial Infarction flow grade 3 (51.0% versus 18.0%; <0.001) and had smaller infarct size (21.91±10.84% versus 26.85±12.37%; =0.016). There was no increase in major bleeding (r-SAK, 1.0% versus control, 3.0%; =0.616).

Conclusions: A single bolus r-SAK before primary PCI for ST-segment-elevation myocardial infarction improves infarct-related artery patency and reduces infarct size without increasing major bleeding.

Registration: URL: https://www.clinicaltrials.gov; Unique identifier: NCT05023681.