The risks of stroke or systemic embolism and major bleeding are considered similar between paroxysmal and sustained atrial fibrillation (AF), and warfarin has demonstrated superior efficacy to aspirin, irrespective of the AF type. comparable (RR, 0.96; 95% CI, 0.85C1.08). We were unable to detect the superiority of anticoagulation over antiplatelets for paroxysmal AF (RR, 0.72; 95% CI, 0.43C1.23), while it was more effective than antiplatelets for sustained AF (RR, 0.42; 95% CI, 0.33C0.54). NOACs showed superior efficacy over 891494-64-7 warfarin and trended to show reduced major bleeding irrespective of the AF type. The AF type is a predictor for thromboembolism, and might be helpful in stroke risk stratification model in combination with other risk factors. With the appearance of novel anticoagulant and antiplatelet agents, the best antithrombotic choice for paroxysmal AF needs further exploration. INTRODUCTION Atrial fibrillation (AF) is associated with 2- to 7-fold increased risks of stroke1C5 and higher occurrence of noncentral nervous system (non-CNS) systemic embolism.5 The correlation between AF and stroke, particularly paroxysmal AF, defined as recurrent AF that terminates spontaneously and lasts up to 7 days, has drawn much 891494-64-7 attention in recent years. Covert paroxysmal AF has been proposed as a potential cause of embolic heart stroke of undetermined resource (ESUS),6 and book electrocardiogram (ECG) monitoring methods with 30-day time event-triggered recorders7 and insertable cardiac screens8,9 possess discovered paroxysmal AF to become connected with cryptogenic ischemic heart stroke.7,8 The AF type is known as irrelevant towards the stroke risk generally,5,10,11 and the distinction between paroxysmal AF and persistent AF has not been used to guide the choice of stroke prophylaxis; however, increasing studies have suggested that paroxysmal AF carries a lower risk of stroke compared with sustained (persistent or permanent) AF.12C18 Whether thromboembolic risk varies by AF type remains uncertain.11,13,15C21 The reported relative stroke risks between paroxysmal and sustained AF may be confounded by the treatment of differential anticoagulant use in patients with paroxysmal and sustained AF in some studies.18,20C23 Therefore, comparing the risk of thromboembolism between different AF types by performing a pooled analysis according to antithrombotic treatment assignment is needed. Warfarin is considered more efficacious than aspirin for stroke prevention in AF10,24,25,45; thus, anticoagulation prophylaxis is recommended for at-risk patients with paroxysmal or sustained AF.5,10,26 However, few studies have specifically evaluated the efficacy and safety of anticoagulant versus antiplatelet agents for paroxysmal AF, and the choice of thromboembolic prophylaxis for paroxysmal AF has become more diversified with the emergence of novel antiplatelet and anticoagulant agents. Novel oral anticoagulants (NOACs) have shown a favorable riskCbenefit profile for AF, with reductions in stroke or systemic embolism and 891494-64-7 similar major bleeding risk as for dose-adjusted warfarin27C29; however, whether their advantages extend to both AF types is unknown. Accordingly, we conducted this meta-analysis to assess the differences in thromboembolism and bleeding risk between paroxysmal and sustained AF patients according to the antithrombotic therapy used, and to detect whether there 891494-64-7 was a difference in the treatment effect between anticoagulation versus antiplatelets and NOACs versus warfarin in such patients. METHODS Data Sources and Searches The Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) guidelines were followed. We firstly identified published studies that compared the efficacy and safety outcomes by AF type in patients randomized to antithrombotic therapies through systematically searching Medline (Ovid, 1946 to September 2014), Embase (Ovid, 1974 to September 2014), Cochrane Central Register of Controlled Trials (CENTRAL) (Ovid, September 2014), and China Biology Medicine disc (SinoMed, 1978 to September 2014). We updated the search up to October week 1, 2015 for any additional eligible studies. Medical subject headings (MeSH) and the terms atrial fibrillation, AF, stroke, brain infarction, brain vascular accident, cerebrovascular accident, and embolism were used and the randomized controlled trials (RCT) filters for Medline and Embase in Ovid Expert Search were applied (see Text message 1, Supplemental Content material, which illustrates the search technique). No vocabulary restriction was utilized. Additionally, we evaluated the research lists of related evaluations by hand, editorials, and research identified after name and abstract 891494-64-7 testing for potential relevant research. This cross-checking was repeated until no more Mouse monoclonal to HER-2 studies were determined. Research Selection Two reviewers (YC and YZ) performed the analysis selection individually, with disagreements resolved through dialogue or by common sense of the third reviewer (JZ). The analysis inclusion criteria had been: stage III RCTs evaluating the effectiveness and protection of NOACs, warfarin, or antiplatelet therapy in AF individuals; studies.