Left Atrial Appendage Closure in Patients With a Mechanical Mitral Valve Prosthesis: A Multicentre Italian Pilot Study

Background: In patients with atrial fi brillation (AF) on vitamin K antagonist (VKA) therapy and therapeutic international normalized ratio (INR) range, the incidence of cardiac thromboembolism is not negligible, and the subgroup of patients who have a mechanical prosthetic mitral valve (PMV) has the highest risk. We aimed to assess the long-term effects of left atrial appendage closure (LAAC) in AF patients with a mechanical PMV who experienced a failure of VKA therapy. Methods: In this retrospective, multicentre study, patients underwent LAAC because of thrombotic events including transient ischemic attack and/or stroke, systemic embolism, and evidence of left atrial appendage thrombosis and/or sludge, despite VKA therapy, were enrolled. Patients with a mechanical PMV were included and compared with those affected by nonvalvular AF. The primary endpoint was the composite of all-cause death, major cardiovascular events, and major bleedings at follow-up. The feasibility and safety of LAAC also were assessed. Results: A total of 55 patients (42% female; mean age, 70 f 9 years), including 12 with a mechanical PMV, were enrolled. The most-frequent indication to LAAC (71%) was LAA thrombosis or sludge. Procedural success was achieved in 96% of overall cases, and in 100% of patients with a PMV. In 35 patients, a cerebral protection device was used. During a median follow-up of 6.1 f 4.3 years, 4 patients with a PMV, and 20 patients without a PMV, reported adverse events (hazard ratio 0.73 [95% confidence fi dence interval 0.25-2.16, P = 0.564]). Conclusions: LAAC seems to be a valuable alternative in patients with AF who have a mechanical PMV, with failure of VKA therapy. This off- label, real-world clinical practice indication deserves validation in further studies.