Effects of mechanical circulatory support devices in patients with acute myocardial infarction undergoing stent implantation: a systematic review and meta-analysis of randomised controlled trials

OBJECTIVE: The survival benefit of using mechanical circulatory support (MCS) in patients with acute myocardial infarction (AMI) is still controversial. It is necessary to explore the impact on clinical outcomes of MCS in patients with AMI undergoing stenting. DESIGN: Systematic review and meta-analysis. DATA SOURCES: Embase, Cochrane Library, Medline, PubMed, Web of Science, ClinicalTrials.gov and Clinicaltrialsregister.eu databases were searched from database inception to February 2021. ELIGIBILITY CRITERIA: Randomised clinical trials (RCTs) on MCS use in patients with AMI undergoing stent implantation were included. DATA EXTRACTION AND SYNTHESIS: Data were extracted and summarised independently by two reviewers. Risk ratios (RRs) and 95% CIs were calculated for clinical outcomes according to random-effects model. RESULTS: Twelve studies of 1497 patients with AMI were included, nine studies including 1382 patients compared MCS with non-MCS, and three studies including 115 patients compared percutaneous ventricular assist devices (pVADs) versus intra-aortic balloon pump (IABP). Compared with non-MCS, MCS was not associated with short-term (within 30 days) (RR=0.90; 95% CI 0.57 to 1.41; I(2)=46.8%) and long-term (at least 6 months) (RR=0.82; 95% CI 0.57 to 1.17; I(2)=37.6%) mortality reductions. In the subset of patients without cardiogenic shock (CS) compared with non-MCS, the patients with IABP treatment significantly had decreased long-term mortality (RR=0.49; 95% CI 0.27 to 0.90; I(2)=0), but without the short-term mortality reductions (RR=0.51; 95% CI 0.22 to 1.19; I(2)=17.9%). While in the patients with CS, the patients with MCS did not benefit from the short-term (RR=1.09; 95% CI 0.67 to 1.79; I(2)=46.6%) or long-term (RR=1.00; 95% CI 0.75 to 1.33; I(2)=22.1%) survival. Moreover, the application of pVADs increased risk of bleeding (RR=1.86; 95% CI 1.15 to 3.00; I(2)=15.3%) compared with IABP treatment (RR=1.86; 95% CI 1.15 to 3.00; I(2)=15.3%). CONCLUSIONS: In all patients with AMI undergoing stent implantation, the MCS use does not reduce all-cause mortality. Patients without CS can benefit from MCS regarding long-term survival, while patients with CS seem not.