Anticoagulants did not reduce thromboembolic events after surgical aortic valve replacement (SAVR), a pooled analysis found, yet the medication did correlate with a higher risk of bleeding.
Compared with aspirin or placebo, warfarin was associated with a higher risk of bleeding (odds ratio 1.38, 95% CI 1.07-1.78), according to Haris Riaz, MD, of Cleveland Clinic, and colleagues.
Warfarin was not tied to fewer venous thromboembolic events, strokes, or transient ischemic attacks at 3 months (OR 1.01, 95% CI 0.56-1.84) or beyond 3 months either (OR 1.08, 95% CI 0.61-1.91), the investigators reported online in Circulation: Cardiovascular Quality and Outcomes.
These data run “contrary to current guideline recommendations” that 3 months of anticoagulation may be reasonable after bioprosthetic surgical replacement of the aortic valve, the group noted.
Perhaps a shorter duration would be better, given that “the perioperative period is a well-known hypercoagulable milieu, and the risk of thromboembolism in these patients rapidly declines over time. As such, any benefit from anticoagulation would likely be seen very early after surgery,” Riaz and colleagues argued.
The meta-analysis included 13 observational studies — four retrospective, nine prospective — for a total of 24,641 cases of aortic valve replacement with bioprosthetics.
Riaz and colleagues noted that “whether our findings are applicable to patients who undergo transcatheter aortic valve replacement is currently unknown.”
For those patients, guidelines recommend dual antiplatelet therapy but are silent on anticoagulation, including for patients with comorbidities for which it is used.
“The best manner in which to determine the value of anticoagulation in these patients and patient with surgical aortic valve replacement would be with a randomized controlled trial that would ideally be triple armed (antiplatelet versus anticoagulant versus placebo),” they wrote. “Until that time, our analysis suggests that anticoagulation of bioprosthetic valves in the absence of other indications for thrombosis prevention seems to be a dangerous practice.”
Riaz disclosed no relevant relationships with industry.
Circulation: Cardiovascular Quality and Outcomes
Riaz H, et al “Safety and use of anticoagulation after aortic valve replacement with bioprostheses: a meta-analysis” Circ Cardiovasc Qual Outcomes 2016; DOI: 10.1161/CIRCOUTCOMES.115.002696.