Efficacy of left ventricular unloading strategies during venoarterial extracorporeal membrane oxygenation in patients with cardiogenic shock: a protocol for a systematic review and Bayesian network meta-analysis

Introduction Venoarterial extracorporeal membrane oxygenation (VA-ECMO) has been widely used for patients with refractory cardiogenic shock. A common side effect of this technic is the resultant increase in left ventricular (LV) afterload which could potentially aggravate myocardial ischaemia, delay ventricular recovery and increase the risk of pulmonary congestion. Several LV unloading strategies have been proposed and implemented to mitigate these complications. However, it is still indistinct that which one is the best choice for clinical application. This Bayesian network meta-analysis (NMA) aims to compare the efficacy of different LV unloading strategies during VA-ECMO. Methods and analysis PubMed, Embase, the Cochrane Library and the International Clinical Trials Registry Platform will be explored from their inception to 31 December 2020. Random controlled trials and cohort studies that compared different LV unloading strategies during VA-ECMO will be included in this study. The primary outcome will be in-hospital mortality. The secondary outcomes will include neurological complications, haemolysis, bleeding, limb ischaemia, renal failure, gastrointestinal complications, sepsis, duration of mechanical ventilation, length of intensive care unit and hospital stays. Pairwise and NMA will respectively be conducted using Stata (V.16, StataCorp) and Aggregate Data Drug Information System (V.1.16.5), and the cumulative probability will be used to rank the included LV unloading strategies. The risk of bias will be conducted using the Cochrane Collaboration's tool or Newcastle-Ottawa Quality Assessment Scale according to their study design. Subgroup analysis, sensitivity analysis and publication bias assessment will be performed. The Grading of Recommendations Assessment, Development and Evaluation will be conducted to explore the quality of evidence. Ethics and dissemination Either ethics approval or patient consent is not necessary, because this study will be based on literature. The results will be disseminated through peer-reviewed publications and conference presentations. PROSPERO registration number CRD42020165093.