Non‐vitamin K oral anticoagulants versus warfarin for left atrial appendage thrombus resolution in nonvalvular atrial fibrillation or flutter

Abstract

Background Non‐vitamin K oral anticoagulants (NOACs) have emerged as alternatives to vitamin K antagonists in select situations. For left atrial (LA) appendage thrombus in nonvalvular atrial fibrillation (AF) or flutter, guidelines recommend oral anticoagulation (OAC) for at least 3 weeks prior to reassessment. Data comparing NOACs to warfarin in this scenario are scarce. Methods A retrospective study identified subjects with nonvalvular AF or flutter who were: a) noted to have LA thrombus detected on transesophageal echocardiography (TEE), b) previously not receiving long‐term OAC; and c) evaluated for resolution of LA thrombus by follow‐up TEE between 3 weeks to less than 1 year of the initial TEE. Results The study included 45 subjects with mean age 63.2 years, 69% male, 78% white race/ethnicity, 42% paroxysmal, and mean CHA2DS2‐VASc score 3.4 ± 1.7. All LA thrombi were confined to the appendage. OAC received included apixaban (3), dabigatran (13), rivaroxaban (6), and warfarin (23), The median follow‐up time to repeat TEE was 67 (interquartile range, 49‐96) days. LA appendage thrombus resolution rates were 76% for the entire cohort, 77% for NOACs, and 74% for warfarin. In univariable logistic regression analysis, LA appendage thrombus resolution was similar for NOACs when compared to warfarin (odds ratio, 1.20; 95% confidence interval, 0.31‐4.69; P = .79). Conclusions In patients nonvalvular AF or flutter who were OAC naïve at the time of diagnosis with LA appendage thrombus, complete resolution was similar between NOACs and warfarin.

Outcome of non‐vitamin K oral anticoagulants in the treatment of left atrial/left atrial appendage thrombus in patients with nonvalvular atrial fibrillation

“…Transesophageal echocardiography (TEE) is a sensitive method for identifying intracardiac thrombus 2 . As complete thrombus resolution is mandatory before AF ablation or cardioversion, it is crucial that the prescribed medication have effective anticoagulation 3 . The administration of vitamin K antagonists (VKAs), such as warfarin, has been the mainstay treatment for intracardiac thrombus, with the target international normalized ratio of 2.0 to 3.0.…”

Oral anticoagulants for left atrial thrombus resolution in nonvalvular atrial fibrillation or flutter: Building the pyramid of evidence for off‐label drug use

“…LA thrombus resolution rates from smaller studies provide important preliminary data for power calculations to determine target sample sizes for such definitive studies. The limitations of our study raised by Dr Tak and colleagues will hopefully be addressed at that time.…”

“…Retrospective cohort studies are important to build the “pyramid of evidence,” given few NOAC studies . It is our anticipation that multicenter randomized controlled trials and prospective cohort studies will ultimately address whether NOACs are reasonable, or perhaps even preferable, alternatives to warfarin for treatment of LA thrombus in nonvalvular AF or flutter.…”

“…Oral anticoagulants for left atrial thrombus resolution in nonvalvular atrial fibrillation or flutter: Building the pyramid of evidence for off-label drug use Dr Tak and colleagues raised important considerations regarding our study on the comparative effectiveness of non-vitamin K oral anticoagulants (NOACs) versus warfarin for left atrial (LA) appendage thrombus resolution in nonvalvular atrial fibrillation (AF) or flutter. 1 These arose largely due to the study design as missing data in medical records and nonstandardized imaging acquisition are common limitations of retrospective cohort studies.…”

Management of left atrium appendage thrombosis in nonvalvular atrial fibrillation patients

“…We have read with interest a recent article comparing non‐vitamin K oral anticoagulants (NOACs) and warfarin for left atrial appendage (LAA) thrombus resolution in nonvalvular atrial fibrillation (AF) or flutter reported by Hussain et al. They concluded that in patients with nonvalvular AF or flutter who were OAC naïve at the time of LA appendage thrombus diagnosis, treatment with NOACs and warfarin for at least 3 weeks had similar rates of complete LA appendage thrombus resolution . We believe that their study is likely to form a valuable addition to the literature.…”