Although these procedures can result in excellent outcomes by splitting open fused commissures to re- lieve stenosis, both the catheter-based and the surgical procedures require a high level of expertise and should be performed at experienced centers. In the United States, there has been a 7.5% decrease in the use of PMBC, accompanied by a 15.9% increase in complica- Excellent short- and long-term outcomes can be achieved with surgical commissurotomy, but surgical commissurotomy is not routinely or widely performed by most surgeons in the United States. Thus, in the clini- cal decision-making process for a patient with rheumat- ic MS, it is essential to know the results of the available interventional procedures. Mitral valve replacement is an option for treatment only if there is no other option and the patient has severe limiting symptoms (Figure 7). Recommendation-Specific Supportive Text 1. Randomized trials have established the safety and efficacy of PMBC as compared with surgical closed or open commissurotomy in patients with a Recommendations for Intervention for Rheumatic MS (Continued) COR LOE Recommendations CLINICAL STATEMENTS AND GUIDELINES favorable valve morphology with less than 2+ MR in the absence of LA thrombus.6,8 12 PMBC is per- formed by advancing one or more balloon cath- eters across the mitral valve and inflating them, thereby splitting the commissures. Favorable valve morphology consists of mobile and relatively thin valve leaflets, which are free of calcium, in the absence of significant subvalvular fusion.18,19,22,23 An anatomic mitral morphology score can be used to determine suitability for PMBC and to evaluate the appearance of the commissures and degree of calcification.1,24,25 Clinical factors, such as age, NYHA class, and presence or absence of AF, are also predictive of outcome. 