Efficacy and Safety Profile of Novel Oral Anticoagulants in the Treatment of Left Atrial Thrombosis: A Systematic Review and Meta-Analysis.

Background: The presence of left atrial/left atrial appendage thrombosis is associated with a higher risk of thromboembolic events in patients with atrial fibrillation. The optimal antithrombotic strategy is not established to date. Objective: Our aim was to compare the efficacy and safety profile of novel oral anticoagulants with warfarin in the treatment of left atrial/left atrial appendage thrombosis. Methods: We conducted a systematic search in PubMed, Embase, Cochrane Library, ClinicalTrials.gov, and 3 Chinese databases for all randomized controlled trials and cohort studies (PROSPERO, CRD42021238952) from inception to 7 May 2021. Two authors independently performed the articles selection, data extraction, and quality assessment. The efficacy outcome was the resolution of left atrial/left atrial appendage thrombosis, and the safety outcomes were bleeding and stroke/transient ischemic attack. Results: One randomized controlled trial and 5 cohort studies were included, with a total of 353 patients. Compared with warfarin, novel oral anticoagulants were associated with increased probability of left atrial/left atrial appendage thrombosis resolution (OR = 2.20; 95% CI, 1.35-3.60; I 2 = 0%). Compared with warfarin, novel oral anticoagulants had a similar risk of bleeding (OR = 0.91; 95% CI, 0.39-2.13; I 2 = 0%). There was no evidence of increased risk of stroke/transient ischemic attack (OR = 0.42; 95% CI, 0.12-1.45; I 2 = 0%). Conclusions: Novel oral anticoagulants were more effective than warfarin in promoting the resolution of left atrial/left atrial appendage thrombosis, without increased risks of bleeding and stroke/transient ischemic attack. Our study provides valuable insight into clinical practice. Further well-designed randomized controlled trials are needed to fully evaluate the benefits and risks in these patients. PROSPERO Registration No.: CRD42021238952.