Protocol for a systematic review and network meta-analysis of the management of new onset atrial fibrillation in critically unwell adult patients

BACKGROUND: New onset atrial fibrillation is the most commonly encountered arrhythmia in critically unwell patients with a reported incidence of 4% to 29%. The occurrence of new onset atrial fibrillation may precipitate acute heart failure and lead to thromboembolic complications as well as being associated with increased in-hospital and in intensive care unit (ICU) mortality. Despite being common, much of our current knowledge regarding the treatment of new onset atrial fibrillation comes from patients with chronic atrial fibrillation or post cardiac surgery. It is unclear if management strategies in these patient cohorts can be applied to new onset atrial fibrillation in the general ICU. This protocol for a systematic review and network meta-analysis aims to address this uncertainty and define what is the most effective management strategy for the treatment of new onset atrial fibrillation (NOAF) in acutely unwell adult patients. METHODS: In this systematic review and network meta-analysis, we plan to search electronic databases (Cochrane Central Register of Controlled Trials [CENTRAL], MEDLINE, EMBASE, Science Citation Index Expanded on Web of Science and relevant trial registries) for relevant randomised and non-randomised trials. Citations will be reviewed by title, abstract and full text by two independent reviewers and disagreement resolved by discussion and a third independent reviewer, if necessary. The Cochrane Risk of Bias tool will be used to assess risk of bias in randomised trials and the Risk of Bias in Nonrandomised Studies of Interventions (ROBINS-I) tool will be used for non-randomised studies. Statistical analysis will be carried out using R package meta and netmeta. We will first conduct a pairwise meta-analysis. If conditions for indirect comparison are satisfied and suitable data are available, we will conduct network meta-analysis using frequentist methodology. Treatments will be ranked according to efficacy with associated P-scores. We will assess the quality of the evidence in the pairwise using GRADE methodology and network meta-analysis comparisons in the CINeMA module in R package meta. DISCUSSION: Our review will be the first to assess direct and indirect evidence to assess the efficacy and rank the treatments available for new onset atrial fibrillation in critically unwell patients. Our review findings will be applicable to the care of people in a range of acute settings including, ICU, the emergency department and acute medical units. SYSTEMATIC REVIEW REGISTRATION: PROSPERO registry number: CRD42019121739.