Time-to-reperfusion in patients with acute myocardial infarction and mortality in prehospital emergency care: meta-analysis

BACKGROUND: People living in rural areas usually suffer comparatively disadvantaged emergency health care than those living in urban areas, reasons including long transit time due to geographic factors. As for many time critical diseases, it is necessary to obtain treatment as quickly as possible. METHODS: Screening of eligible studies were conducted based on inclusion an exclusion criteria. A comprehensive search was conducted by using following database: EMBASE, Medline, Cochrane library and Scopus. Quality assessment tool for observational cohort and cross-sectional study is used for assessing the risk of bias. The time group were defined based on the median or mean transit time among patients. In symptom onset-balloon time, we take 120 min transit time as the standard so patients in included studies are divided into two groups:less than 120 min (group A) and more than 120 min (group B). The collected data were used for quantitative analysis, they were inputted into Review Manager Software (v5.3) to produce summary results. RESULTS: Ten studies representing 71,099 patients were included in the meta-analysis. All studies were retrospective and prospective observational studies and RCTs in which patients experienced ST-elevation myocardial infarction (STEMI) and were treated with percutaneous coronary intervention (PCI). Random effects meta-analysis of the point estimate was 0.69 (CI 0.60, 0.79). Heterogeneity between study results was evaluated via examination of the forest plots and quantified by using I(2) statistic. Heterogeneity in two stage time was moderate among studies (I(2) = 29%, P = 0.23). CONCLUSION: The meta-analysis for included studies report less mortality in less than 120 min symptom onset-balloon and door-balloon time than that in more than 120 min. It is necessary to optimize the prehospital system for rapid decision making and logical destination and mode of transport with prehospital notification of the cath lab so that the hospital is ready to optimize door to balloon time.