The trends in use of direct oral anticoagulants (DOAC) in patients with bioprosthetic heart valves in the U.S. were evaluated in this retrospective observational study using data extracted from the Society of Thoracic Surgeons Adult Cardiac Surgery Database between July 2014 and June 2017. Although there have been previous retrospective cohort studies demonstrating safety for the use of DOAC in patients with bioprosthetic valves and atrial fibrillation, this study included a larger cohort of patients. 29,719 patients with mechanical valves and 148,421 patients with bioprosthetic valves were included in the analysis. Not surprisingly, given prior data from ReALIGN showing harm in mechanical valve recipients treated with dabigatran, only 88 (about 1%) patients out of the entire cohort of mechanical valve patients in the present study received DOAC. These patients tended to be older, with concomitant atrial fibrillation or flutter, and had more reoperation for bleeding (post-op bleeding 9.1% vs. 3.0%). In-hospital stroke rates were similar in the DOAC and warfarin groups (3.4% vs. 1.2%, p=0.06).
Among the cohort of patients with bioprosthetic valves, 5.89% of patients with mitral bioprosthetic valves and 4.66% of patients with aortic bioprosthetic valves were discharged on off-label DOAC. The remainder were discharged on warfarin. Older patients, men, and patients with higher body weight were more often treated with DOAC. The DOAC group also had high rates of pre-op DOAC use and had more comorbidities such as hypertension, diabetes, cerebrovascular disease, PVD, hyperlipidemia, liver disease, prior MI and arrhythmia. Interestingly, in this cohort, reoperation for bleeding was less common in the DOAC arm as compared to the warfarin arm (2.6% vs. 3.4%, p<0.001). Comparison of rates of non-surgical site bleeding was not shared in this registry analysis.
The major limitations to this study are the observational data and lack of long-term follow up. All data was peri-procedural (pre-operative and pre-discharge). This study showed that, consistent with current guidelines, DOAC use in patients with mechanical valves remains appropriately uncommon in the U.S. DOAC use in patients with bioprosthetic valves in the U.S. has nearly doubled between 2014 and 2017 (from almost 4% to nearly 8%), although remains relatively low. Randomized controlled trial data is needed to definitively demonstrate the safety and efficacy of DOACs in patients with bioprosthetic aortic and mitral valves.