Successful Resolution of a Large Left Atrial and Left Atrial Appendage Thrombus with Rivaroxaban

Rivaroxaban versus warfarin for the management of left ventricle thrombus

Background

Rivaroxaban has been recently introduced for the management of non-valvular intra-cardiac thrombosis with variable results. We aimed to compare the results of the off-label use of rivaroxaban versus warfarin in the management of patients with left ventricle (LV) thrombus. This research is a retrospective study conducted on 63 patients who had LV thrombus from January to December 2016. We compared patients treated with warfarin (n=35) to patients who had rivaroxaban (n=28), and study outcomes were time to thrombus resolution, bleeding, stroke, and mortality.

Results

The median duration of treatment was 9.5 (25th-75th percentiles: 6-32.5) months for rivaroxaban and 14 (3-41) months for warfarin. Thrombus resolution occurred in 24 patients in the warfarin group (68.6%) and 20 patients in the rivaroxaban group (71.4%). The median time to resolution in the warfarin group was 9 (4-20) months and 3 (2-11.5) months in the rivaroxaban group. Thrombus resolution was significantly faster in patients on rivaroxaban (p= 0.019). Predictors of thrombus resolution were thrombus surface area (HR: 1.21; CI 95% (1.0-1.46); p= .048) and the use of rivaroxaban (HR: 1.92; CI 95% (1.01-3.65); p= 0.048). There was no difference in stroke, bleeding, and mortality between both groups.

Conclusion

Rivaroxaban was as effective and safe as warfarin in managing patients with left ventricle thrombus. Larger randomized clinical trials are recommended to confirm our findings.

The Rare Occurrence of a Left Atrial Thrombus in a Dog

Intracardiac thrombi are rare in dogs. If they occur, they are mostly seen in the right atrium while only two case reports describing a mural left atrial thrombus in dogs are available. This case report describes a 14-year-old mixed-breed bitch that was presented at the clinic because of dyspnoea. The dog suffered from alopecia for about three years and displayed polyuria and polydipsia for a number of months. Clinical examination revealed intensified inspiratory and expiratory respiratory sounds and various heart sounds. Chest X-ray showed cardiomegaly (VHS 11) and a mixed bronchoalveolar lung pattern of the caudal lung. A transthoracic echocardiography was performed and showed a moderate mitral regurgitation, a highly dilated left atrium, a low-grade pulmonary insufficiency, and a minimal aortic and tricuspid insufficiency. Additionally, a free-floating ball thrombus was found in the left atrium. Hyperadrenocorticism was indicated by an ACTH stimulation test. The previous medical therapy of the referring veterinarian consisted of benazepril and furosemide and was complemented by clopidogrel. The pet owners declined any further clinical diagnostics and therapy. The dog died 19 days later. This is the first reported case of a dog with a free-floating left atrial thrombus. Specific therapeutic strategies for intracardiac thrombi in the dog are currently not available, and therefore, every patient should be treated individually.