2020 Focused Update of the 2017 ACC Expert Consensus Decisio
The document is a focused update of the 2017 ACC Expert Consensus Decision Pathway on the Management of Mitral Regurgitation, with some sections updated and others added in light of the publication of new trial data related to secondary MR, among other developments.

The following are key points to remember:
1. The ECDP continues to emphasize clinical assessment in terms of the identification of MR; the determination of the etiology and mechanism of MR (primary, secondary, or mixed; using the Carpentier classification); determination of MR severity; assessment in appropriate patients of the feasibility of surgical or transcatheter intervention; and indications for consideration for referral to a regional, comprehensive valve center.
2. The assessment of MR severity primarily relies on echo/Doppler, and should be done using an integrative approach that incorporates multiple parameters, including semi-quantitative measures (vena contracta width or area) and quantitative measures (effective regurgitant orifice area [EROA], regurgitant volume [RVol], and regurgitant fraction [RF]).
3. Associated findings also should be evaluated as part of the assessment of MR severity, including left atrial and left ventricular (LV) size, and pulmonary artery systolic pressure (PASP).
4. Primary and secondary MR have important differences in terms of prognosis, evaluation, and management.
5. Differences in the assessment of MR severity in primary versus secondary MR in part relate to differences in orifice shape; the effect of blood pressure on MR; and the impact of LV size on the relationships between EROA, RVol, and RF.
6. The ECDP includes recommendations regarding referral of patients to a comprehensive valve center based on the etiology and severity of MR, the clinical context, symptoms, LV size and systolic function, and (in the setting of secondary MR or mixed primary and secondary MR) the response to guideline-directed management.
7. The principal treatment of primary MR is surgery. Surgeon experience has been recognized as an important determinant of successful mitral valve repair. Referral for repair to an experienced mitral surgeon at a heart valve center should be considered for patients with severe MR in whom other cardiac diseases require concomitant operative management, for patients in whom complex repair of primary MR is considered.
8. Transcatheter edge-to-edge clip mitral repair can be considered among patients with primary MR and severe symptoms who are poor surgical candidates.
9. Surgical correction of secondary MR may improve symptoms and quality of life, but has not been shown to improve survival.
10. Surgical or transcatheter treatment for secondary MR should be undertaken only after appropriate medical and device therapies have been instituted and optimized as judged by the multidisciplinary team, with input from a cardiologist experienced in managing heart HF and MR.
11. Long-term follow-up of patients after surgical or transcatheter mitral valve intervention is essential for the assessment of durability of MR reduction, functional outcomes, and survival.

Source: https://www.acc.org/latest-in-cardiology/ten-points-to-remember/2020/02/12/17/08/2020-focused-update-of-the-2017-mr-ecdp