DOAC versus VKA in patients with atrial fibrillation and bioprosthetic valves: a systematic review and meta-analysis

INTRODUCTION AND OBJECTIVES

Direct oral anticoagulant (DOAC) therapy has been shown to be safe and effective in patients with atrial fibrillation (AF). However, outcomes in AF patients with bioprosthetic valves are unclear, as this population has been underrepresented in clinical trials. The aim of this study was to assess the safety and efficacy of DOACs in this population based on the existing published literature.

METHODS

A systematic search and review were conducted to identify randomized clinical trials and comparative observational studies published from 2017 to January 2022 that compared DOACs and vitamin K antagonists (VKAs) in AF patients with bioprosthetic valves. Hazard ratios (HR) were collected to compare the 2 treatments in terms of cardiovascular and all-cause mortality, stroke/systemic embolism, and major bleeding. A meta-analysis combining the results was performed.

RESULTS

We included 12 studies (30 283 patients). DOACs and VKAs were compared based on HRs at the 95% confidence interval. DOAC therapy was associated with a significant 9% reduction in all-cause mortality (HR, 0.91; 95%CI, 0.85-0.97; P=.0068; I2=8%), with no significant differences in the risk of stroke/systemic embolism (HR, 0.87; 95%CI, 0.67-1.14; P=.29; I2=45%) or major bleeding (HR, 0.82; 95%CI, 0.67-1.00; P=.054; I2=48.7%).

CONCLUSIONS

DOAC therapy in AF patients with bioprosthetic valves may be associated with a significant reduction in all-cause mortality, with no reduction in the efficacy of stroke/systemic embolism prevention or increase in major bleeding risk.

Real Structural Valve Deterioration of the Mitroflow Aortic Prosthesis: Competing Risk Analysis

INTRODUCTION AND OBJECTIVES

The Mitroflow aortic prosthesis is a bovine pericardial bioprosthesis specially designed to increase the valve area in relation to its size. There is controversy regarding the pattern of structural valve deterioration (SVD). Our aim was to determine the cumulative incidence of SVD, risk factors influencing its occurrence, and its impact on mortality.

METHODS

A total of 1028 patients were clinically and echocardiographically followed up. Because the study population was elderly and had heart disease, we used a competing risk analysis.

RESULTS

The percentage of patients with SVD at 5 years was 4.22% (95%CI, 2.96-5.81) and was 15.77% at 8 years (95%CI, 12.46-19.43). The incidence was higher for small valves (19mm and 21mm) reaching 6.43% at 5 years (95%CI, 4.48-8.84) and 20.06% at 8 years (95%CI, 15.53-25.01). Severe patient-prosthesis mismatch (PPM) influenced the incidence of SVD (_sHR, 3.53; 95%CI, 2.20-5.66; P < .001) but moderate PPM had no impact. The most powerful predictor of mortality was the presence of SVD (HR, 4.59; 95%CI, 2.91-7.22; P < .001).

CONCLUSIONS

This study used a definition based on the increase in the transprosthetic gradient and found a higher incidence of SVD of the Mitroflow prosthesis than that reported by other series, especially for sizes 19mm and 21mm and in patients with severe PPM. The incidence of SVD increased exponentially from the fifth year after implantation and its occurrence led to a 4.5-fold increase in the risk of death.