Thromboembolic events early after mitral valve repair: incidence and predictive factors

The incidence of thromboembolic events (TE) in the early period following mitral valve repair (MV repair) is poorly documented. The aim of this prospective study was to evaluate it, and to determine predictive factors.

In this prospective multicenter non-randomized study, 350 consecutive patients were included after MV repair and monitored until post-operative day 44+/-6. 65.7% received Vitamin K antagonists (VKA), 18.8% aspirin (ASA), 5.4% ASA+VKA and 10% received no antithrombotic therapy (AT). All patients with AF received VKA or VKA+ASA. Twelve patients had a cerebral TE during follow-up:14.3% among untreated patients, 3.0% in the VKA group, and 0% in the ASA and in the ASA+VKA groups (p=0.03 for comparison no AT group versus the three other combined groups; p=NS for VKA versus ASA). In univariate analysis, only the absence of post-operative AT was related to the risk of TE (HR=6.7, CI 95%[2.1-21], p=0.0002). In a prespecified subgroup (n=185) of patients with sinus rhythm and without concomitant cardiac surgery (in which the choice of AT is not influenced by these associate conditions), only the absence of post-operative AT remained related to the risk of TE (HR=10.0, CI 95%[2.45-40], p=0.001).

In the first six weeks following MV repair, the incidence of thromboembolic events is far from negligible (3.5%), even in patients with sinus rhythm. The main predictive factor for thromboembolic event determined in this study is the absence of an antithrombotic therapy.