Strategy to Reduce Mortality Rates of ST-elevation Acute Myocardial Infarction Using Prehospital Thrombolysis: A Meta-analysis

Abstract

Abstract Importance: Ischemic heart disease is the leading cause of death worldwide. In ST-elevation myocardial infarction (STEMI), delaying reperfusion from the onset of chest pain increases the incidence of mortality and morbidity. Prehospital thrombolysis (PHT) has been evaluated in the setting of STEMI. We performed a systematic analysis of studies of PHT in acute STEMI. Objective: The objective of this study was to evaluate the all-cause mortality benefit in STEMI with PHT during short-term and long-term follow-up. Data Sources: In December 2020, the Cochrane search strategy was used to analyze randomized control trials, nonrandomized control studies, and registry studies in PubMed, EMBASE, Cochrane Library, Google Scholar, ClinicalKey, and Clinical Trial Registries. The search was repeated, and the included studies were updated in June 2023 to include more recent literature. We restricted the analysis to full-text publications in English. Study Selection: Studies using any thrombolytic agent in treating acute myocardial infarction in prehospital and inhospital settings with or without percutaneous Coronary intervention (PCI) were included in the analysis. Selection criteria included patient history and symptoms, electrocardiogram findings, and cardiac markers. Data Extraction: We used the Cochrane Handbook for Systematic Reviews of Interventions for assessing bias, the PRISMA flow diagram to show the process of inclusion and exclusion of studies, and RevMan software to perform meta-analysis. Main Outcomes and Measures: Outcomes include all-cause hospital mortality rate of PHT versus inhospital thrombolysis (IHT), influence of ischemic median time on all-cause mortality with PHT, and effect of PHT before PCI. The measures must have been observed for a follow-up period of up to 35 days, 1-year, and 5-years. Results: Data from 63,814 patients from 32 studies were reviewed. Results indicate a reduction in all-cause mortality in patients assigned to PHT (odds ratio [OR] −0.68, P < 0.00001) compared to IHT. There was a significant reduction in mortality when thrombolytics were administered before PCI (OR − 0.78, P = 0.0001). The overall survival was better with an ischemic time of <2 h. Mortality was higher with longer ischemic time (3 h and 6 h). Among patients who presented within 2 h of the onset of chest pain, mortality was lower compared to primary PCI (pPCI). Conclusion: PHT offers faster reperfusion and reduces all-cause mortality compared to IHT. A strategy of PHT within the first 2-3 h of ischemic pain followed by PCI (if indicated) could offer better survival than pPCI.