Effect of different pre-hospital first aid methods on the efficacy and prognosis of acute myocardial infarction with left heart failure: a systematic review and meta-analysis

BACKGROUND: Pre-hospital first aid for acute myocardial infarction (AMI) is an important way to save patients. However, there are still some disputes about the way of pre-hospital first aid. Therefore, this paper provides a Meta-analysis to evaluate the efficacy and prognosis of different prehospital care for AMI with left heart failure. METHODS: By searching the published studies in the databases, the literature related to the pre-hospital first aid for patients with AMI and left heart failure was screened out. The quality of the literature was evaluated according to the Newcastle-Ottawa scale (NOS), and the corresponding data were extracted for meta-analysis. Meta-analysis was performed on 7 outcome indicators (clinical effect of patients after treatment, respiratory rate, heart rate, systolic blood pressure (SBP), diastolic blood pressure (DBP), survival status, and incidence of complications). A funnel plot and Egger’s test were used to test risk of bias. RESULTS: A total of 16 articles were finally included, comprising a total of 1,465 patients. The literature quality evaluation found that 8 literatures were rated as low risk of bias, and 8 literatures were rated as medium risk of bias. The meta-analysis results showed that the clinical effect of the first aid and then transportation group was better than that of the transportation and then first aid group [risk ratio (RR) =1.35, 95% confidence interval (CI): 1.27 to 1.45, P<0.01]; the respiratory rate decreased [mean difference (MD) =−4.84, 95% CI: −6.50 to −3.18, P<0.01]; the heart rate decreased (MD =−11.34, 95% CI: −12.69 to −9.99, P<0.01); SBP decreased (MD =−6.00, 95% CI: −10.00 to −2.00, P<0.01); the DBP decreased (MD =−3.54, 95% CI: −4.45 to −2.64, P<0.01); the survival status of the patients improved (RR =1.29, 95% CI: 1.18 to 1.41, P<0.01); the incidence of complications was reduced (RR =0.31, 95% CI: 0.20 to 0.48, P<0.01). CONCLUSIONS: Pre-hospital first aid and then transportation can significantly improve the clinical treatment effect of patients. However, considering that the literatures included in this paper are non-randomized controlled studies and the overall quality of the included literatures is not high and the number of studies is limited, further exploration is needed.