Abstract 10998: Estimated Surgical Risk and Anatomical Compatibility for MitraClip Intervention in Patients With Severe Mitral Regurgitation According to Valve Disease Etiology

Abstract

Background: Percutaneous mitral valve repair using the MitraClip technology was originally introduced to treat degenerative (myxomatous) mitral regurgitation (DMR), but it is currently mostly used in patients (pts) with functional (ischemic) MR (FMR). We examined whether this approach was justified, based on surgical risk and valve anatomy. Methods: Consecutive pts with severe MR who were hospitalized at a tertiary care medical center were identified and their clinical records and echocardiographic studies were reviewed. Surgical risk was estimated using the Society of Thoracic Surgeons (STS) risk scores. The anatomical compatibility for MitraClip invervention was assessed using the Endovascular Valve Edge-to-Edge Repair Study (EVEREST) echocardiographic criteria. Results: Of 236 pts included in the study during 3 yrs, the cause of MR was FMR in 104 pts (44.1%), DMR in 84 (35.6%), and other causes (mainly endocarditis and rheumatic disease) in 48 (20.3%). Age and gender distribution were similar in pts with FMR (age 71±14 years, 62.5% male) and DMR (age 73±14 years, 66.7% male) and severe NYHA III/IV heart failure symptoms justifying intervention were evident in 73.1% and 60.7% of pts, respectively (P=0.10). Using multiple risk scores, the estimated surgical risk (mortality and major morbidity) for mitral valve repair or replacement (with or without bypass surgery) was consistently much higher in pts with FMR than DMR. Valve anatomy was suitable for MitraClip intervention in 87 pts (83.7%) with FMR versus only 38 pts (45.2%) with DMR (P<0.001). Assuming the most common type of surgery was valve repair for DMR and annuloplasty + bypass surgery for FMR, and using an STS estimated mortality greater than 10% to define high surgical risk, only 6 pts with DMR (7.1%) had a clinical indication for intervention, high surgical risk, and valve anatomy suitable for MitraClip intervention, versus 21 pts (20.2%) with FMR (P<0.001). Using an STS estimated mortality and morbidity greater than 20% to define high surgical risk, these proportions were 20 pts (23.8%) for DMR and 60 pts (57.7%) for FMR (P<0.001). Conclusion: Higher surgical risk and better anatomical compatibility justify the greater use of MitraClip intervention in patients with FMR than in patients with DMR.