Abstract
BACKGROUND: The long-term effects of early thrombolytic therapy administered within 120 minutes of the first medical contact and before primary percutaneous coronary intervention (PCI) on left ventricular (LV) and left atrial (LA) function in ST-segment elevation myocardial infarction (STEMI) patients remain unknown. This study aimed to explore the long-term effects of early recombinant staphylokinase (r-SAK) thrombolysis administered up to 120 minutes before primary PCI on the LV and LA function of STEMI patients using cardiac magnetic resonance (CMR) imaging. METHODS: This retrospective study analyzed the one-year follow-up CMR imaging data of STEMI patients enrolled in the multi-center, prospective OPTIMA-5 trial, conducted from November 2021 to August 2022. Patients were randomized to receive either a single half-dose of 5 mg r-SAK or normal saline (NS) before primary PCI. LV and LA functional parameters were compared between groups using appropriate statistical tests. RESULTS: A total of 66 patients were included (r-SAK, n=32; NS, n=34). Compared to the NS group, the r-SAK group had a significantly higher cardiac index (2.77 vs. 2.41 L/min/m(2), P=0.018), LV stroke volume index (42.18 vs. 37.77 mL/m(2), P=0.029), LV wall thickening (49.86% vs. 44.36%, P<0.001), and LV wall motion (6.02 vs. 5.57 mm, P=0.015). The segmental circumferential strain of the non-infarcted myocardium was also superior (-19.36% vs. -17.90%, P<0.001). In relation to LA function, the r-SAK group showed better LA conduit function [change in left atrial volume index (△LAVI): 8.27 vs. 5.69 mL/m(2), P=0.004], LA passive ejection fraction (27.34% vs. 20.68%, P=0.007), passive strain (21.80% vs. 17.05%, P=0.045), and peak early negative strain rate (-1.80 vs. -1.50 1/s, P=0.043). CONCLUSIONS: The early administration of r-SAK thrombolysis before primary PCI significantly improves long-term LV and LA function in STEMI patients, suggesting a potential strategy for enhancing cardiac recovery.