Efficacy and safety of different antithrombotic treatment regimens in patients undergoing transcatheter mitral valve repair and atrial fibrillation; A meta-analysis and systematic review

Background Optimal antithrombotic therapy following transcatheter mitral valve repair (TMVR/TEER) in patients with atrial fibrillation remains uncertain, with substantial practice variation and reliance on nonrandomized data. Methods We performed a systematic review and network meta-analysis of observational studies evaluating antithrombotic strategies after TMVR/TEER with atrial fibrillation. Antithrombotic regimens were harmonized into two main categories: oral anticoagulation [OAC; including vitamin K antagonists [VKAs] and direct oral anticoagulants [DOACs]] and antiplatelet therapy (APT; including aspirin or clopidogrel, alone or in combination). Outcomes of interest were ischemic stroke, major bleeding, and all-cause mortality. Pairwise and network random-effects models were applied to derive odds ratios (ORs) with 95% confidence intervals (CIs). Results Four multicenter observational cohorts ( n = 2,098) were included. Across comparisons, OAC strategies demonstrated a favorable profile compared with APT for bleeding risk reduction, while DOACs showed heterogeneous results depending on comparator drug and study region (phenprocoumon in Europe vs. warfarin in the U.S.). Mortality findings consistently favored OAC (particularly DOACs) potential benefits over APT. For stroke, OAC (phenprocoumon) showed better ischemic prevention, indicating more effectiveness in minimizing stroke risk compared with APT. Network geometry was limited, with most contrasts informed by only one or two studies. Conclusions In patients undergoing TMVR/TEER with atrial fibrillation, OAC strategies appeared to be associated with lower bleeding risk and potentially favorable mortality outcomes compared with antiplatelet therapy. However, conclusions regarding comparative efficacy, particularly for stroke prevention, should be interpreted cautiously due to the limited number of studies and the observational nature of the available evidence. Thus, the evidence base remains limited by observational design, heterogeneous comparators, and inconsistent outcome definitions. Randomized trials are urgently needed to guide antithrombotic management in this high-risk population.