# Mitral Regurgitation

A decision-focused approach to confirming severity, separating primary from secondary mitral regurgitation, selecting repair versus transcatheter therapy, and identifying patients whose ventricular remodeling or heart failure burden warrants multidisciplinary valve intervention.

**Clinical question:** How should clinicians quantify, phenotype, and direct intervention for clinically significant primary or secondary mitral regurgitation?

Updated: 2026-08-21T02:26:39.298335+00:00

## What matters in practice
- After MR is identified, determine whether it is primary valve-apparatus disease or secondary LV disease; mechanism changes natural history, severity interpretation, and treatment selection. [1]
- Use an integrated echocardiographic assessment rather than a single measurement; severe primary MR is conventionally associated with EROA at least 40 mm² and regurgitant volume at least 60 mL, while lower quantitative thresholds have been used for severe secondary MR. [9][11][24]
- In degenerative MR requiring intervention, refer to a multidisciplinary valve team and an experienced mitral surgeon when durable repair is feasible. [2][13]
- For secondary MR, optimize heart failure management and assess anatomy in a Heart Team pathway before transcatheter edge-to-edge repair; randomized trial evidence supports MitraClip-based therapy in selected patients with heart failure and severe MR. [2][8][20]
- PISA-derived EROA and regurgitant volume can underestimate secondary MR when the orifice is elliptical or multiple jets are present; consider three-dimensional imaging when discordance affects management. [24]

## Establish mechanism before assigning a treatment pathway

The first actionable distinction is primary versus secondary MR.

Use transthoracic echocardiography (TTE) to define leaflet motion, annular and subvalvular anatomy, LV size and systolic function, left atrial size, and pulmonary pressure estimates. Describe leaflet motion with the Carpentier classification because this links the observed jet to valve pathology and repair strategy. [1]

Classify MR as primary when the initiating lesion is within the valve apparatus, such as degenerative leaflet prolapse or flail and chordal abnormality. Classify MR as secondary when LV disease causes leaflet malcoaptation; this distinction is essential because natural history, severity interpretation, and treatment choices differ. [1]

Obtain transesophageal echocardiography (TEE) when TTE does not adequately define leaflet or chordal anatomy, when repairability is uncertain, or when transcatheter edge-to-edge repair (TEER) is being considered. Dedicated review of echocardiographic and cross-sectional imaging by experienced valve clinicians should precede a multidisciplinary decision on intervention. [1][2]
- Primary MR: identify the abnormal leaflet, segment, chordae, and direction of the jet to determine surgical repair feasibility. [1][2]
- Secondary MR: define the underlying LV phenotype and involve a heart failure specialist in the multidisciplinary assessment. [2]
- When MR mechanism, severity, symptoms, and ventricular response are discordant, use complementary imaging rather than relying on one linear LV measurement or ejection fraction alone. [1]

*Mechanism-based classification directs imaging interpretation and intervention planning. [1][2]*

| MR phenotype | Key imaging finding | Immediate next action |
| --- | --- | --- |
| Primary MR | Abnormality of the mitral valve apparatus; use Carpentier leaflet-motion classification to define mechanism. [1] | Assess likelihood of durable surgical repair and obtain TEE when anatomy is insufficiently defined on TTE. [1][2] |
| Secondary MR | MR arising from LV disease and leaflet malcoaptation rather than intrinsic valve disease. [1] | Integrate heart failure expertise, optimize the heart failure pathway, and assess candidacy for valve intervention through a multidisciplinary team. [2][20] |
| Indeterminate or discordant MR | Incongruent qualitative jet findings, quantitative measures, chamber remodeling, or clinical status. [1][24] | Review image quality and use three-dimensional echocardiography or CMR when additional anatomic or volumetric clarification will alter management. [1][24] |

## Grade MR with an integrated echocardiographic assessment

Quantitative thresholds must be interpreted in the context of mechanism and jet geometry.

For severe MR, integrate vena contracta, effective regurgitant orifice area (EROA), regurgitant volume, regurgitant fraction, jet characteristics, pulmonary venous flow, and ventricular response rather than making a decision from any isolated metric. The American Society of Echocardiography threshold cited for severe MR includes vena contracta greater than 0.7 cm, regurgitant volume greater than 60 mL, and regurgitant fraction greater than 50%. [9]

For holosystolic primary MR, EROA of at least 40 mm² and regurgitant volume of at least 60 mL are conventional severe-MR thresholds. Quantitative Doppler data likewise identified severe MR thresholds of 60 mL regurgitant volume, 50% regurgitant fraction, and 40 mm² effective orifice area. [11][24]

Secondary MR requires special caution. An EROA of at least 20 mm² or regurgitant volume of at least 30 mL has been used as a severe-MR threshold in guideline-based frameworks, but PISA can substantially underestimate severity when the regurgitant orifice is elliptical or multiple jets are present. Consider three-dimensional EROA assessment when this limitation changes referral or procedural decisions, recognizing that three-dimensional imaging may overestimate actual EROA. [24]
- Interpret PISA cautiously in multiple jets, elliptical secondary-MR orifices, and dynamic MR. [24]
- A prolapse-related EROA may emerge or increase in mid-to-late systole, whereas secondary MR may decrease during mid-systole; a holosystolic lesion has different quantitative implications. [24]
- Track LV chamber size and systolic function longitudinally, but do not assume a single linear LV dimension captures remodeling; primary MR may preferentially remodel the apex and mid-cavity. [1]

*Quantitative findings used to identify severe MR require mechanism-specific interpretation. [9][11][24]*

| Measure | Severe primary MR | Secondary-MR interpretation |
| --- | --- | --- |
| Vena contracta | Greater than 0.7 cm is a cited severe-MR criterion. [9] | Use within an integrated assessment; secondary MR is often geometrically complex. [9][24] |
| EROA | At least 40 mm² for holosystolic primary MR. [11][24] | At least 20 mm² has been used as a severe threshold; PISA may underestimate an elliptical orifice. [24] |
| Regurgitant volume | At least 60 mL for holosystolic primary MR. [11][24] | At least 30 mL has been used as a severe threshold; interpret with jet geometry and timing. [24] |
| Regurgitant fraction | At least 50% supports severe MR. [9][11] | Use as part of an integrated assessment rather than as a stand-alone trigger. [9][24] |

## Route primary MR to durable repair when intervention is indicated

Repairability and center expertise are decisive in degenerative MR.

For severe symptomatic MR, surgical mitral repair is the preferred therapeutic option when degenerative anatomy has a high likelihood of successful repair; valve replacement is the alternative when intervention is indicated but repair is not feasible or durable. [13]

Refer patients being considered for mitral intervention through a multidisciplinary valve team that identifies lesion severity, the intended intervention, and the appropriate surgeon or operator. For degenerative disease amenable to repair, use a surgeon with dedicated mitral expertise and contemporary repair outcomes; referral to another center is appropriate when local repair expertise is insufficient. [2]

Use TEE-based segmental anatomy to distinguish lesions likely to support repair from those that may require replacement or transcatheter alternatives. The procedural plan should specify whether the valve is repairable before treatment selection, rather than treating all severe primary MR as interchangeable. [1][2]
- Favor repair over replacement when degenerative anatomy is repairable and intervention is required. [13]
- Do not determine candidacy from MR grade alone; document mechanism, repairability, ventricular response, symptoms, and procedural risk for Heart Team review. [1][2]
- For patients evaluated for transcatheter treatment, obtain imaging adequate to define leaflet anatomy and procedural feasibility. [1][2]

*Intervention pathway for primary MR emphasizes anatomy and repair expertise. [1][2][13]*

| Clinical finding | Preferred decision | Reason for escalation |
| --- | --- | --- |
| Degenerative MR with anatomy amenable to durable repair | Refer for surgical mitral repair by an experienced mitral surgeon. [2][13] | Repair is the first-line operative option in severe symptomatic degenerative MR when success is likely. [13] |
| Intervention indicated but durable repair unlikely | Consider mitral valve replacement as the surgical alternative. [13] | Replacement is used when indicated intervention cannot be reliably repaired. [13] |
| Uncertain anatomy or procedural suitability | Obtain expert TEE review and multidisciplinary valve-team assessment. [1][2] | Leaflet and chordal definition determines repairability and treatment choice. [1] |

## Treat secondary MR as a heart failure and valve disease problem

Secondary MR management requires heart failure optimization and anatomic selection for intervention.

Secondary MR is common, increases with age, and is associated with excess mortality. Its treatment pathway should include a heart failure specialist because the valve lesion arises in the setting of LV disease and the expected benefit of intervention depends on patient phenotype. [2][5]

For patients with secondary MR being considered for intervention, perform Heart Team review after defining MR mechanism and severity, reviewing TTE and any CMR or other cross-sectional imaging, and determining the planned procedure. The multidisciplinary group should function as the entry point for patients under consideration for mitral intervention. [2]

TEER with MitraClip has randomized-trial evidence in selected patients with heart failure and secondary MR. COAPT was a multicenter randomized controlled trial of MitraClip in patients with heart failure and MR, and five-year follow-up reported lower rates of all hospitalizations and heart failure hospitalizations with transcatheter repair. [7][8] Divergent results between COAPT and MITRA-FR reinforce that secondary-MR phenotyping and patient selection are central rather than optional. [6][20][21]
- Involve heart failure expertise before TEER selection for secondary MR. [2]
- Use the same multidisciplinary review to determine severity, procedural suitability, and the operator or surgeon. [2]
- Do not extrapolate TEER benefit to every secondary-MR phenotype; the contrasting MITRA-FR and COAPT results require individualized anatomic and clinical selection. [6][20][21]

### Interpreting trial differences

MITRA-FR reported a 54.6% primary-outcome rate, including 24.3% all-cause mortality and 48.7% unplanned hospitalization, while COAPT demonstrated benefit from MitraClip-based TEER in a selected heart failure population. These trials support referral for structured selection rather than a reflex procedural approach based solely on the presence of secondary MR. [6][8][20]

*Secondary-MR intervention decisions require integrated heart failure and valve assessment. [2][6][7][8][20]*

| Decision point | Action | Interpretation |
| --- | --- | --- |
| Secondary MR recognized on TTE | Define LV-related mechanism and quantify MR with an integrated study. [1][24] | Secondary MR cannot be managed as primary degenerative valve disease. [1] |
| Considering valve intervention | Refer to a Heart Team that includes heart failure expertise and reviews all relevant imaging. [2] | The team should identify lesion severity, intervention, and operator or surgeon. [2] |
| TEER contemplated | Assess MitraClip/TEER suitability through structured clinical and imaging selection. [2][8][20] | COAPT supports benefit in selected patients, whereas MITRA-FR underscores that outcomes vary across phenotypes. [6][7][8][20] |

## Monitor ventricular response and reassess when anatomy or physiology changes

Serial imaging should detect progression before irreversible remodeling narrows treatment options.

Follow LV chamber size and function longitudinally after MR is identified, because contemporary guidance uses LV dimensions and ejection fraction as intervention triggers in asymptomatic patients. Interpret serial change with awareness that one linear measurement may miss nonuniform remodeling, particularly in primary MR. [1]

Use CMR or three-dimensional echocardiography selectively when TTE-derived quantification is limited by image quality, eccentric or multiple jets, or discordant ventricular remodeling. CMR offers more reproducible and accurate volumetric tracking than linear dimensions, although volumetric thresholds have not been established as guideline intervention triggers. [1]

Re-refer for multidisciplinary review when serial TTE shows worsening MR, evolving LV size or function, new uncertainty about repairability, or a change in candidacy for surgical or transcatheter intervention. Imaging should be available for expert review before the intervention decision is finalized. [1][2]
- Do not use CMR-derived LV volumes as a stand-alone intervention trigger; use them to resolve uncertainty and track change. [1]
- Repeat expert imaging review when changing geometry alters the distinction between primary and secondary MR or changes repair/TEER feasibility. [1][2]
- For any planned intervention, document the mechanism, severity, imaging evidence, and procedural plan in the multidisciplinary assessment. [2]

*Imaging escalation is most useful when standard TTE does not resolve a management decision. [1][2][24]*

| Problem on follow-up | Next test or review | Decision consequence |
| --- | --- | --- |
| Uncertain leaflet or chordal pathology | TEE with expert valve-imaging review. [1][2] | Clarifies mechanism, repairability, and transcatheter feasibility. [1][2] |
| Possible PISA underestimation in secondary MR | Consider three-dimensional EROA assessment. [24] | May better characterize an elliptical or multiple-jet lesion, while recognizing potential overestimation. [24] |
| Need for reproducible serial chamber assessment | Consider CMR volumetric assessment. [1] | Improves volumetric tracking but does not replace established guideline triggers based on linear dimensions and ejection fraction. [1] |

## Common questions

### When should an apparent severe MR measurement be questioned?

Question a single severe or nonsevere quantitative value when jet geometry, timing, chamber response, and clinical status are discordant. PISA may underestimate secondary MR with an elliptical orifice or multiple jets; three-dimensional imaging can help but may overestimate EROA. [1][24]

## References
1. Imaging assessment of mitral and aortic regurgitation: current state of the art | Heart — heart.bmj.com — https://heart.bmj.com/content/106/22/1769
2. Getting the best from the Heart Team: guidance for cardiac ... — heart.bmj.com — https://heart.bmj.com/content/108/11/e2
3. Secondary tricuspid valve regurgitation: a forgotten entity — heart.bmj.com — https://heart.bmj.com/content/101/22/1840
4. Shadows and light in transcatheter mitral valve treatment — heart.bmj.com — https://heart.bmj.com/content/111/17/797
5. Burden, treatment use, and outcome of secondary mitral ... — www.bmj.com — https://www.bmj.com/content/373/bmj.n1421
6. the Gulf MTEER registry (GULF Mitral Transcatheter Edge ... — bmjopen.bmj.com — https://bmjopen.bmj.com/content/13/9/e073549
7. Five-Year Follow-up after Transcatheter Repair ... — www.nejm.org — https://www.nejm.org/doi/full/10.1056/NEJMoa2300213
8. Transcatheter Mitral-Valve Repair in Patients with Heart ... — www.nejm.org — https://www.nejm.org/doi/full/10.1056/NEJMoa1806640
9. Percutaneous Interventions for Secondary Mitral Regurgitation — www.ahajournals.org — https://www.ahajournals.org/doi/10.1161/CIRCINTERVENTIONS.120.008998?url_ver=Z39.88-2003&amp%3Brfr_id=ori%3Arid%3Acrossref.org&amp%3Brfr_dat=cr_pub%3Dpubmed
10. Quantitation of Mitral Regurgitation | Circulation — www.ahajournals.org — https://www.ahajournals.org/doi/10.1161/circulationaha.112.121590
11. Grading of Mitral Regurgitation by Quantitative Doppler ... — www.ahajournals.org — https://www.ahajournals.org/doi/10.1161/01.CIR.96.10.3409
12. Valvular Heart Disease in Circulation and the ... — www.ahajournals.org — https://www.ahajournals.org/doi/10.1161/CIRCULATIONAHA.112.115501
13. Thrombotic Risk and Antithrombotic Strategies After Transcatheter Mitral Valve Replacement — www.jacc.org — https://www.jacc.org/doi/10.1016/j.jcin.2019.07.055
14. Functional Mitral Regurgitation and the Role of ... — www.sciencedirect.com — https://www.sciencedirect.com/science/article/pii/S2474870624001027
15. Mitral valve disease—current management and future ... — www.sciencedirect.com — https://www.sciencedirect.com/science/article/abs/pii/S0140673616005584
16. ACC/AHA and ESC/EACTS Guidelines for the ... — www.sciencedirect.com — https://www.sciencedirect.com/science/article/pii/S0735109723059739
17. Review Article Secondary Mitral Regurgitation — www.sciencedirect.com — https://www.sciencedirect.com/science/article/abs/pii/S1071916424002744
18. MitraClip Versus Surgery for Secondary Mitral ... — onlinelibrary.wiley.com — https://onlinelibrary.wiley.com/doi/10.1002/ccd.70114
19. European Journal of Heart Failure expert consensus ... — onlinelibrary.wiley.com — https://onlinelibrary.wiley.com/doi/full/10.1002/ejhf.70043
20. The management of secondary mitral regurgitation in patients ... — academic.oup.com — https://academic.oup.com/eurheartj/article/42/13/1254/6174642
21. Randomized controlled trials in valvular heart disease — academic.oup.com — https://academic.oup.com/ehjcimaging/article/27/2/187/8375584
22. Comparison of Meta-Analytical Estimates Between Surgical ... — academic.oup.com — https://academic.oup.com/icvts/article/41/1/ivaf269/8404457
23. Cardiac remodelling and clinical outcomes after mitral edge-to ... — academic.oup.com — https://academic.oup.com/ehjimp/article/4/3/qyag106/8706724
24. Clinical Trial — www.acc.org — https://www.acc.org/-/media/Non-Clinical/Files-PDFs-Excel-MS-Word-etc/Tools-and-Practice-Support/Quality-Programs/Valve-Meeting/Stone-2015-Clinical-Trial-Design-Part-1.pdf

## Editorial note

Prepared from cited clinical literature using Astra's research workflow. Verify recommendations against current guidance and patient-specific factors.