Association between D-dimer levels and clinical events in patients with mechanical heart valve replacement under oral anticoagulation therapy

Abstract

Objective: To investigate the association between D-dimer levels and clinical events in patients with mechanical heart valve replacement under oral anticoagulation therapy. Methods: This prospective study included 640 consecutive patients underwent mechanical heart valve replacement in Wuhan Asia Heart Hospital between January 2013 and June 2014.Patients were assigned to abnormal D-dimer group (D-dimer level>cut off value, n=88) and normal D-dimer group (D-dimer level≤cut off value, n=552) according to D-dimer levels measured at 3 months after the initiation of oral anticoagulation therapy.All patients were followed up for 24 months or until the observation of the end points, which included thrombotic events, bleeding events and all-cause deaths.The anticoagulation therapy was monitored once per 1-2 months by the international normalized ratio (INR), and the target value was 1.8-3.0. Results: During a follow-up period of 24 months, rates of total clinical events (19.30%(17/88) vs. 5.8%(32/552), P<0.01), thrombotic events (11.4%(10/88) vs. 2.3%(13/552), P<0.01), and all-cause deaths (8.0%(7/88) vs. 2.0%(11/552), P<0.01) were all significantly higher in abnormal D-dimer group than in normal D-dimer group.There were no significant difference in bleeding events between the two groups (2.3%(2/88) vs. 3.1%(17/552), P=0.77). Multivariate Cox regression analysis showed that high D-dimer level was an independent risk factor of total clinical events (HR=3.86, 95%CI 1.92-7.76, P<0.01), thrombotic events(HR=5.29, 95%CI 2.12-13.10, P<0.01), and all-cause deaths(HR=5.32, 95%CI 1.71-16.60, P<0.01), but which was not correlated with bleeding events(HR=1.36, 95%CI 0.27-6.84, P=0.71). Conclusion: Elevated D-dimer levels are linked with clinical events in patients with mechanical heart valve replacement under oral anticoagulation therapy.