Indications For Treatment

The 2014 American Heart Association (AHA)/American College of Cardiology (ACC) Guideline for the Management of Patients With Valvular Heart Disease specifies 3 indications for surgical intervention.10 Repair of the MV is now preferred to MV replacement when possible, due to superior long-term outcomes.8 Current indications for mitral valve repair as prescribed by the AHA/ACC 2014 guidelines are listed in Table 1.

Table 1. ACC/AHA Indications for MR Repair


Continue Reading

Stage

Class of Recommendation

Severe chronic primary symptomatic MR

D

I

Severe chronic primary asymptomatic MR with:

(1)   LV dysfunction (EF 30-60% or LVESD >40mm)

(2)  Preserved LV function if repair success likelier than 95% with expected mortality less than 1%

(3)  Preserved LV function with new onset atrial fibrillation or pulmonary hypertension (PAP >50 mm Hg)

 

C2

 

C1

C1

 

I

 

IIa

 

IIa

Severe chronic secondary symptomatic MR with: persistent NYHA III or IV symptoms despite medical therapy

D

IIb

LV = left ventricular; LVESD = left ventricular end-systolic diameter; MR = mitral regurgitation; PAP = pulmonary artery pressure

When surgical intervention is not feasible, additional criteria have been suggested to identify candidates for percutaneous repair in addition to those above. These include severely symptomatic NYHA class III or IV HF despite medical optimization, favorable anatomy (Table 2),14 reasonable life expectancy, and high surgical risk. 10 Assessment of surgical risk should be performed with either the European System for Cardiac Operative Risk Evaluation (EuroSCORE) or the Society of Thoracic Surgeons (STS) operative mortality risk score.

Table 2. Favorable Anatomy for MitraClip Intervention

Central MR jet

Flail leaflet width <15 mm, gap <10 mm

Minimal leaflet calcification

Coaptation depth <11 mm

Large MV opening area > 4 cm2

Mobile length of posterior leaflet >10 mm

MR = mitral regurgitation; MV = mitral valve

Functional MR percutaneous repair has yet to be approved in the United States. However, the most recent European Society of Cardiology (ESC) guidelines recommend MitraClip® (Abbott Vascular, Abbott Park, IL) for severe, symptomatic functional MR (class IIb).15 MitraClip for functional repair continues to be evaluated in observational studies and trials. Percutaneous intervention is contraindicated in MR from rheumatic disease or active endocarditis, or inability to tolerate periprocedural anticoagulation or postprocedural antiplatelet agents.9 Furthermore, MitraClip may be considered in patients with severe, symptomatic MR for whom evidence is lacking for surgical benefit such as those with severe degenerative or functional MR with severe left ventricular failure (EF <30%), including patients with ischemic MR without options for revascularization.14

Transcatheter Repair

The MitraClip is the most common transcatheter MR repair technology  currently in use.6 The transcatheter leaflet repair system based on the surgical Alfieri16 edge-to-edge repair utilizes a cobalt chromium clip to connect the anterior and posterior leaflets under fluoroscopic and echocardiographic guidance.9 After atrial transseptal puncture, the clip is centered over the MR jet and once implanted, functionally increases coaptation, thus reducing regurgitant blood. Complications, though rare, include bleeding requiring transfusion, transseptal complications, clip detachment, and very rarely mitral stenosis or device embolization. Outcomes are assessed using transesophageal echocardiography, and the patient undergoes periprocedural anticoagulation therapy with heparin. Patients must be able to tolerate subsequent dual antiplatelet therapy for 1 month and aspirin for 6 months following the procedure. It is currently the only transcatheter device approved by the US Food and Drug Administration (FDA) for commercial use in 3 to 4+ degenerative MR in patients at high surgical risk, although others are in development. Intervention is considered successful when MR is reduced to grade 2+ or less on echocardiographic assessment, which sometimes necessitates additional clip placement.17