Clinician's dilemma for mitral regurgitation patients once Clipping fails, study seeks to clear the confusion.

One half of the patients with severe symptomatic mitral regurgitation (MR) are not referred for surgery, due either to frailty, multiple comorbidities, or prohibitively high surgical risk. Although durable MR reduction with the MitraClip has been shown with a failure rate ranging between 1.5% and 3% in high-volume centre registries. Subjecting such patients to either surgical correction or transcatheter options is difficult to choose.

Surgical treatment will pose a very high risk because most of these patients were already considered surgical turndowns before the index clipping procedure. Going for another transcutaneous re-clipping attempt has its own technical challenges because optimal grasping site might not be available now and the risk of iatrogenic mitral stenosis is also higher.

To address this lacuna in knowledge, Alessandrini et al enrolled 824 patients who had been treated with the MitraClip device. The aim of this analysis was to evaluate the survival outcome following percutaneous procedures and surgery after unsuccessful TMVR interventions for different aetiologies. 63 (7.6%) symptomatic patients with therapy failure and persistent or recurrent mitral regurgitation (MR) underwent reinterventions.

An outcome analysis for primary (PMR) and secondary mitral regurgitation (SMR) and subsequent percutaneous versus surgical treatment was carried out. MitraClip reinterventions were performed in 36 patients (57.1%; n=26 SMR, n=10 PMR), while 27 (42.9%; n=13 SMR, n=14 PMR) underwent open heart surgery.

Surgical patients with PMR showed lower mortality than patients with SMR (p<0.0001) and ReClip patients with PMR (p=0.073). Atrial fibrillation, prior open heart surgery and chronic obstructive pulmonary disease increased the risk of death. The level of post-interventional MR had no relevant impact on survival.

The authors support the idea that reclipping remains an appropriate treatment option after failed TMVr, especially in patients with functional MR (FMR). Nonetheless, the success rate was quite disappointing, reflecting the technical challenges encountered during reclipping. The 30-day mortality rate was almost comparable to that reported in the surgical group and was somewhat high for a procedure reputed to be safe and less invasive than surgery.

They also favoured a surgical approach for patients with degenerative/primary MR (DMR), with no hospital death reported. All surgical deaths were reported in the FMR patients, patients with more comorbidities and poorer left ventricular function. TMVr or other transcatheter approaches such as transcatheter mitral valve replacement (TMVR) have to be favoured in this subset of patients.

Recently, Lisko et al reported that TMVR after failed TMVr was feasible and safe at 30 days with optimal MR elimination and high procedural success. This finding raises a very interesting discussion on the selection process. Despite the fact that complex mitral anatomies can be successfully treated with the MitraClip by expert operators, TMVR has the advantage over TMVr in that it is suitable for a wide range of mitral valve anatomies, including patients considered anatomically unsuitable for TMVr achieving durable MR elimination. Finally, the authors report predictive prognostic factors of long-term death.

To conclude:

1. After SMR and failed TMVR, reclipping is an appropriate treatment option for symptomatic patients.
2. For PMR patients, surgery must be favoured over a reclipping procedure.
3. Patients with atrial fibrillation, prior open heart surgery and chronic obstructive pulmonary disease are at risk of reduced survival after reinterventions.

Source: Eurointervention journal: Alessandrini H, Dreher A, Harr C, Wohlmuth P, et al. Clinical impact of intervention strategies after failed transcatheter mitral valve repair. EuroIntervention. 2021;16:1447-54.