Woldendorp K, Doyle MP, Black D, Ng M, Keech A, Grieve SM, Bannon PG
J. Thorac. Cardiovasc. Surg. 2020 Feb;
BACKGROUND: Recent high-resolution computed tomography studies after transcatheter aortic valve insertion (TAVI) have reported a high prevalence of subclinical valve thrombosis (SCVT), potentially contributing to increased risk of late stroke. We aimed to investigate SCVT in patients after TAVI, with a focus on prevalence, predisposing factors, management, and potential sequelae.
METHODS: A comprehensive literature review of patients with SCVT after TAVI was carried out on all published studies in 3 major electronic databases from their inception until October 2019. Studies with sufficient data were included in a meta-analysis comparing the risk of stroke between patients with SCVT and those with normal valve function, as well as the protective effects of antiplatelet and anticoagulation on preventing SCVT.
RESULTS: From 3456 patients examined in a comprehensive review, 398 patients (11.5%) demonstrated evidence of SCVT during follow-up. Dual antiplatelet therapy was given in 45.5% of cases, single antiplatelet therapy in 19.8%, and oral anticoagulation in 28.5%. A meta-analysis demonstrated that rates of stroke were more than 3 times greater in patients with SCVT compared with those without (logistic odds, 1.10; 95% confidence interval, 0.63-1.57, P < .0001). Oral anticoagulation was superior to dual antiplatelet therapy or single antiplatelet therapy, preventing the formation of SCVT (logistic odds, -1.05, 95% confidence interval, -1.71 to -0.39, P < .0001).
CONCLUSIONS: Subclinical valve thrombosis is seen in 11.5% of patients after TAVI and is associated with increased risk of stroke. When oral anticoagulation is used postprocedurally, it is more effective than either dual or single-antiplatelet therapy in preventing subclinical valve thrombosis. These findings suggest that further studies are needed to define the optimal antithrombotic regimen to mitigate thrombotic and embolic sequelae after TAVI.