Anticoagulation efficacy of dabigatran etexilate for left atrial appendage thrombus in patients with atrial fibrillation by transthoracic and transesophageal echocardiography

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; I² = 0%). Compared with warfarin, novel oral anticoagulants had a similar risk of bleeding (OR = 0.91; 95% CI, 0.39–2.13; I² = 0%). There was no evidence of increased risk of stroke/transient ischemic attack (OR = 0.42; 95% CI, 0.12–1.45; I² = 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.

Efficiency of the Left Atrial Appendage Thrombus Dissolution in Patients with Persistent Nonvalvular Atrial Fibrillation with Warfarin or Direct Oral Anticoagulants Therapy

Aim. Compare the incidence of the left atrial appendage (LAA) thrombus dissolution in patients with persistent nonvalvular atrial fibrillation receiving warfarin and direct oral anticoagulants (DOAC).

Materials and methods. 68 patients with persistent nonvalvular atrial fibrillation were included in a retrospective study (age was 59.7±9.8 years, 60.3% men), in whom at least one repeated transesophageal echocardiographic examination was performed after detecting a thrombus. After detecting a thrombus in the LAA, 37 (54.4%) patients started or continued taking warfarin in doses that ensure the INR maintenance at the level of 2-3, 14 (20.6%) started or continued taking dabigatran at a dose of 150 mg 2 times/day, 14 (20.6%) started or continued taking rivaroxaban 20 mg 1 time/day and 3 (4.4%) started or continued taking apixaban 5 mg 2 times/day. Repeated transesophageal echocardiographic examination was performed on average 33.3±14.2 days after the first one.

Results. Dissolution of a previously identified thrombus was found in 26 (83.9%) of 31 patients receiving DOAC and in 19 (51.4%) of 37 patients receiving warfarin (p=0.011). The logistic regression analysis showed that the chances of a thrombus dissolution in LAA while taking DOAC are 14.8 times (95% confidence interval [CI] was 2.469-88.72) higher than while taking warfarin. The size and the rate at which blood is expelled from the LAA also have an independent influence on the chances of thrombus dissolution. An increase in the size of a thrombus by 1 mm reduces the chances of a thrombus dissolution by 1.136 (95% CI was 1.040-1.244) times, and an increase in the rate of blood expulsion from the LAA by 1 cm/sec increases these chances by 1.105 (95% CI was 1.003-1.219) times.

Conclusion. In the present study, the incidence of the LAA thrombus dissolution in patients with persistent nonvalvular atrial fibrillation while receiving DOAC was higher than while receiving warfarin.

Management of Direct Oral Anticoagulants in Patients with Atrial Fibrillation Undergoing Cardioversion

Atrial fibrillation the most common cardiac arrhythmia. Its incidence rises steadily with each decade, becoming a real “epidemic phenomenon”. Cardioversion is defined as a rhythm control strategy which, if successful, restores normal sinus rhythm. This, whether obtained with synchronized shock or with drugs, involves a periprocedural risk of stroke and systemic embolism which is reduced by adequate anticoagulant therapy in the weeks before or by the exclusion of left atrial thrombi. Direct oral anticoagulants are safe, manageable, and provide rapid onset of oral anticoagulation; they are an important alternative to heparin/warfarin from all points of view, with a considerable reduction in bleedings and increase in the safety and quality of life of patients.