Antiplatelet versus oral anticoagulant therapy as antithrombotic prophylaxis after mitral valve repair.

OBJECTIVE

To verify the rate of thromboembolic and hemorrhagic complications during the first 6 months after mitral valve repair and to assess whether the type of antithrombotic therapy influenced clinical outcome.

METHODS

Retrospective data were retrieved from 19 centers. Inclusion criteria were isolated mitral valve repair with ring implantation. Exclusion criteria were ongoing or past atrial fibrillation and any combined intraoperative surgical procedures. The study cohort consisted of 1882 patients (aged 58 ± 15 years; 36% women), and included 1517 treated with an oral anticoagulant (VKA group) and 365 with antiplatelet drugs (APLT group). Primary efficacy outcome was the incidence of arterial thromboembolic events within 6 months and primary safety outcome was the incidence of major bleeding within 6 months. Propensity matching was performed to obtain 2 comparable cohorts (858 vs 286).

RESULTS

No differences were detected for arterial embolic complications in matched cohort (1.6% VKA vs 2.1% APLT; P = .50). Conversely, patients in the APLT group showed lower incidence of major bleeding complications (3.9% vs 0.7%; P = .01). Six-month mortality rate was significantly higher in the VKA group (2.7% vs 0.3%; P = .02). Multivariable analysis in the matched cohort found VKA as independent predictor of major bleeding complications and mortality at 6 months.

CONCLUSIONS

Vitamin K antagonist therapy was not superior to antiplatelet therapy to prevent thromboembolic complications after mitral valve repair. Our data suggest that oral anticoagulation may carry a higher bleeding risk compared with antiplatelet therapy, although these results should be confirmed in an adequately powered randomized controlled trial.