Introduction

The edge-to-edge procedure is increasingly being used as an interventional therapy for symptomatic higher-grade mitral regurgitation (MR). In most patients, MR is accompanied by atrial fibrillation, requiring oral anticoagulation. The protective effect of MR on thrombus formation in left atrial appendage (LAA) is known, which may be relevant for patients undergoing interventional MR therapy in whom (direct) oral anticoagulants are contraindicated.

This report refers to a case in which a thrombus formed in LAA after the implantation of a mitral valve clip (MVC) and a severe bleeding complication occurred with a fatal outcome after restarting anticoagulation.

Case report

An 83-year-old female with permanent atrial fibrillation and symptomatic, functional MR grade 4+ underwent an MVC implantation in April 2019. Pre-interventional transesophageal echocardiography (TEE) showed no evidence of LAA thrombus, although the patient had not taken oral anticoagulation since 2008 after severe bleeding into the right thigh and due to amyloid angiopathy and thrombocytopathy.

After the MVC implantation, there was a good intervention result with a reduction of the MR to grade 1+. The transmitral mean pressure gradient was 2 mmHg, and three months of aspirin (ASA) and clopidogrel therapy was initiated. This was followed by the administration of ASA mono. As early as 2019, the patient was recommended an implantation of an LAA occluder, but she refused it at that time.

In August 2021, the patient was readmitted due to decompensated heart failure with preserved ejection fraction, chronic right heart strain and severe tricuspid regurgitation. Transthoracic echocardiography continued to show residual MR grade 1–2+ with regular clip location (Figure 1). As the patient meanwhile agreed to the LAA occluder implantation, TEE was performed. However, this revealed a thrombus in the LAA (Figure 2). In addition to atrial fibrillation with a CHA₂DS₂‐VASc score of 6 and MR reduction, the following risk factors for thrombus formation in the LAA were identified: thrombogenically reduced flow in the LAA (22 cm/s in April 2019, 19 cm/s in August 2021), highly dilated left atrium (153 ml/m2) and EPO therapy for renal insufficiency.

Subsequently, treatment with rivaroxaban was started at a renal-adapted dose (15 mg 1 x daily). At the follow-up after three months, the thrombus showed a reduction in size; thus, a decision was made to continue the previous treatment and carry out another check-up three months later.

In the meantime, however, the patient was readmitted to the hospital due to renewed cardiac decompensation and recurrent urinary bladder tamponades requiring two transurethral hematoma evacuations. In this context, there was a progressive deterioration of the patient’s general condition with increasing renal failure and uremia. As no intensive medical measures including dialysis were desired by the patient and her proxies, exitus letalis followed in January 2022.

Summary

The implantation of an MVC may lead to LAA thrombus formation. We identified potential thrombogenic risk factors in patients that may justify simultaneous implantation of an MVC and an LAA occluder. This case may give rise to further research in this area.

Figure 1. 


Figure 2.