Left ventricular thrombi are associated with high rates of stroke and systemic embolism.
While vitamin K antagonists (VKAs) have historically been the anticoagulant of choice,
they have a narrow therapeutic window and require frequent monitoring. Direct oral
anticoagulants (DOACs) offer more predictable anticoagulation but the use of DOACs
to treat left ventricular thrombus has not been well studied. Guideline recommendations
around the topic are based on expert consensus and very low-quality evidence. This
systematic review and meta-analysis compares DOACs or VKAs in the treatment of left
ventricular thrombus. Outcomes of interest were stroke and systemic embolism, thrombus
resolution, any bleeding, major bleeding, and mortality.
METHODS AND RESULTS
We searched CENTRAL, MEDLINE, EMBASE, CINAHL, ACPJC, and Web of Science for studies
comparing DOACs and VKAs in the treatment of left ventricular thrombus. We also searched
reference lists from included studies and relevant conferences’ proceedings. Two reviewers
independently screened titles and abstracts and then the full-text of potentially
relevant citations in duplicate. They then extracted data and evaluated risk of bias
in duplicate. The data was analyzed using Revman 5.3. We used the DerSimonian and
Laird random-effects model to pool the weighted effect of estimates across all studies.
The pooled relative risks (RRs) were calculated with corresponding 95% confidence
intervals (CIs). We assessed the quality of evidence for each outcome using the Grading
of Recommendations, Assessment, Development, and Evaluation approach. Of 443 citations
screened, 12 observational studies (n=2,225) were included. One study (n=98) was prospective,
11 (n=2,127) were retrospective studies, and 3 studies (n=719) had matched controls.
There were no randomized controlled trials found. Most included studies were at high
risk of bias due to unmatched baseline variables. We found no significant difference
in any of our outcomes with DOACs versus VKAs: stroke and systemic embolism (RR 1.14,
95% CI [0.82, 1.58], p=0.43), thrombus resolution (RR 1.02, 95% CI [0.91, 1.15], p=0.69),
any bleeding (RR 1.47, 95% CI [0.65, 3.33], p=0.36), major bleeding (RR 0.22, 95%
CI [0.01, 4.21], p=0.32), and mortality (RR 0.99, 95% CI [0.67, 1.45], p=0.95). Evidence
for each of these outcomes was of very low-quality due to risk of bias and imprecision
of the studies.
Very low quality evidence suggests no difference in outcomes with DOACs versus VKAs
in the treatment of left ventricular thrombus. More robust data are needed to guide