Evaluation of D-dimer levels in patients with prosthetic valve thrombosis: Relationship with thrombus burden and cerebrovascular events

Plasma D-dimer level is an indicator of thrombosis and endogenous fibrinolytic activity. We investigated the association between the D-dimer levels and thrombus burden and cerebrovascular events in patients with obstructive prosthetic valve thrombosis (PVT). This retrospective study included 47 patients with obstructive left-sided PVT and 32 controls in whom PVT was excluded with comprehensive transthoracic and transesophageal echocardiography (TEE). The patient group included 11 aortic, 27 mitral, and 9 aortic and mitral valve PVT patients and the control group included 2 aortic, 25 mitral, and 5 aortic and mitral valve patients. Laboratory analysis including plasma D-dimer levels was performed at the time of admission in all patients. The baseline characteristics were similar between the two groups. The plasma D-dimer levels were significantly higher in patients with obstructive PVT compared with controls [680 (110-3590) vs. 310 (80-380) μg/l; P<0.001]. By multivariate logistic regression analysis high D-dimer level, low-INR value on admission, high NYHA functional class and recent history of cerebrovascular accident (CVA), and transient ischemic attack (TIA) were the independent predictors of obstructive PVT. A plasma D-dimer level of greater than 365μg/l predicted the presence of PVT with a sensitivity of 81% and a specificity of 69% (AUC= 0.781, P<0.001). Plasma D-dimer levels were significantly higher in patients with a recent history of CVA/TIA [2140 (470-2980) vs. 590 (380-830) μg/l; P=0.021]. In addition to the so-called indicators of PVT including subtherapeutic anticoagulation, increased D-Dimer levels may strengthen the suspicion of PVT. Moreover, higher plasma D-dimer levels were associated with higher thrombus burden and higher prevalence of recent CVA/TIA.