Hypothermia as an Adjunctive Therapy to Percutaneous Intervention in ST-Elevation Myocardial Infarction: A Systematic Review and Meta-Analysis of Randomized Control Trials

Abstract

IntroductionIn the setting of acute ST-elevation myocardial infarction (STEMI), several randomized control trials (RCTs) suggested a potential benefit with the use of therapeutic hypothermia (TH). However, results from previous studies are contradictory. MethodWe performed a comprehensive literature search for studies that evaluated the efficacy and safety of adjunctive TH compared to the standard percutaneous coronary intervention (PCI) in awake patients with STEMI. The primary outcomes were the infarct size (IS) and microvascular obstruction (MVO) assessed by cardiac imaging at the end of follow-up. The secondary outcomes were major adverse cardiovascular events (MACE), procedure-related complications, and door-to-balloon time. Relative risk (RR) or the mean difference (MD) and corresponding 95 % confidence intervals (CIs) were calculated using the random-effects model. ResultsA total of 10 RCTs, including 706 patients were included. As compared to standard PCI, TH was not associated with a statistically significant improvement in the IS (MD: -0.87 %, 95%CI: −2.97, 1.23; P = 0.42) or in the MVO (MD: 0.11 %, 95%CI: −0.06, 0.27; P = 0.21). MACE and its components were comparable between the two groups. However, the TH approach was associated with an increased risk of infection and prolonged door-to-balloon time. Furthermore, there was a trend in the TH group toward an increased incidence of stent thrombosis and paroxysmal atrial fibrillation. ConclusionsAccording to our meta-analysis of published RCTs, TH is not beneficial in awake patients with STEMI and has a marginal safety profile with potential for care delays. Larger-scale RCTs are needed to further clarify our results.