Percutaneous bail-out in severe acute mitral regurgitation: when surgery is not an option

Abstract

Functional mitral regurgitation (FMR) worsens heart failure (HF) prognosis, fuels HF progression, and causes an excess mortality. Percutaneous edge-to-edge repair has been proven effective and safe in patients with severe functional mitral regurgitation (MR) at high surgical risk. Beneficial effects in this patient population include reduction in the rate of HF hospitalizations, and improvement in survival, quality of life, and functional capacity. Conversely, patients with acute MR, either ischaemic or disruption of different parts of the mitral valve apparatus, may require urgent surgical revascularization with concomitant repair or replacement. However, certain scenarios may complicate or preclude surgical procedures, such as a poor clinical state resulting in prohibitive surgical risk. Here, a comprehensive evaluation by the multidisciplinary heart team is essential to ponder further therapeutic options. In this issue of European Heart Journal—Case reports, Alachar et al. report a case of transcatheter edge-to-edge mitral valve repair (TMVR) in combination with the Sentinel cerebral protection device in a patient suffering from acute ischaemic MR and left atrial thrombus. In detail, a 59-year-old female patient experienced a sub-acute stent thrombosis 3 weeks after stent implantation in the left circumflex artery causing severe FMR based on a restrictive posterior mitral valve leaflet. After an initial clinical stabilization had been achieved, transoesophageal echocardiography revealed additionally the presence of a thrombus in the left atrial appendage (LAA). Since cardiac magnetic resonance imaging (CMR) demonstrated akinesia and transmural scar of all lateral left ventricular segments coronary reperfusion was deemed futile. In the subsequent days, the patient’s clinical state dramatically deteriorated, requiring vasopressor therapy and cardioversion due to ventricular tachycardia, rendering mitral valve surgery not a feasible option according to the local heart team. Therefore, the authors performed successful TMVR with concomitant use of a cerebral protection device (CPD) as a rescue therapy. The patient was discharged from the intensive care unit haemodynamically stable and without neurological deficits 2 days after the procedure. Documented experience with TMVR in acute MR is scarce and mainly limited to small case series. However, when treating FMR in the setting of acute ischaemia revascularization represents the first therapeutic target. If haemodynamic instability driven by severe FMR persists despite coronary revascularization, the valvular lesion should be treated next. In this specific case, coronary intervention was deemed futile due to the presence of transmural scar detected by CMR further highlighting the significance of multi-modality imaging in valvular heart disease. Furthermore, in the context of the current guidelines, surgery remains the gold standard for treating acute MR in the setting of myocardial infarction. However, FMR patients frequently suffer from multiple co-morbidities with an associated excess in surgical risk, which renders TMVR an attractive alternative treatment option. Shared decision-making enforced by the heart team is indispensable in these cases. Another important aspect of this case is the use of cerebral protection in the presence of LAA thrombus, which usually represents a contraindication for TMVR. In patients undergoing transcatheter aortic valve replacement, the use of the Sentinel dual-filter protection device has been shown to be associated with a significantly lower rate of peri-procedural stroke compared with unprotected procedures. Potential sources of cerebral embolism during transcatheter mitral valve interventions include mitral annulus calcification (MAC), thrombotic material from either the LAA or devices, clip dislocation, and atrial, valvular or ventricular damage. Reported rates of in-hospital stroke during TMVR range from 0.2 to 1.2%, but certainly the occurrence of stroke will be much more likely in the presence of