Carpentier Classification of MR

Does it have any advantage in handling the case?

Mitral valve is extremely complex, any interference, both in its leaflets and strings, besides the adjacent support structures, can lead to varying degrees of dysfunction and consequently varying degrees of regurgitation.

Patients who have advanced degrees of regurgitation cause the left ventricle to live with a chronic high preload and reduced afterload, since the work performed by the myocardium to eject blood into the aorta and left atrium (low pressure) is less than to eject all the blood into the aorta. Therefore, in cases of primary etiology of MR, adequate intervention at the right time can bring an excellent long-term prognosis. Thus, properly identifying the etiology, quantifying and classifying it, in addition to indicating, proposing the correct technique for correction becomes fundamental in echocardiographic evaluation of these patients.

Patients with primary MR comprise a spectrum of diverse diseases, such as myxomatous degeneration, evolving with prolapse (extreme cases such as Barlow’s disease), rheumatic involvement, calcific degeneration (MAC), endocarditis and trauma are cases of clearer indication of intervention in case symptoms or hemodynamic repercussions. The natural history of patients with primary MR who do not undergo treatment invasively shows poor results over the years. There is an inexorable evolution to dilation of the left cavities. This brings loss of systolic function and a greater degree of mitral regurgitation (MR attracts MR).

A very useful tool, both in the diagnosis, classification and in the proposal of surgical treatment, is the Carpentier classification. Initially, the patient is classified between primary and secondary etiology.

Type I is the exclusive involvement of the leaflet, with not alteration in its size or mobility, which is very common in cases of individuals with congenital clefts or endocarditis. Type II is excessive leaflet movement, characteristic of mitral valve prolapse disease. Type III is defined by the limitation of the mobility of the leaflets and is divided into “a” and “b”; “a” is due to rheumatic involvement and type “b” of functional etiology secondary to ischemic disease, that is, rope traction. Since we started talking about the secondary (functional) etiology, we can only talk about functional type I, caused by excessive dilation of the mitral ring and left atrium or by traction of the non-ischemic leaflets.

The importance of this classification is demonstrated at the point where we can find recommendations for intervention in situations other than those exposed in the guidelines. For example, AHA stage C1 patients with mitral regurgitation could be submitted to surgical correction in centers of high expertise if they are classified as Carpentier I or II, that is, very high success rate in repair. Carpentier IIIa patients, generally speaking, may undergo a repairment as an alternative therapy and the early prosthesis deployment may harm the patient.

Suggested literature:

1 – El Sabbagh A, Reddy YNV, Nishimura RA. Mitral Valve Regurgitation in the Contemporary Era: Insights Into Diagnosis, Management, and Future Directions. JACC Cardiovasc Imaging. 2018 Apr;11(4):628-643.

 

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