Mitral regurgitation — structured viva

Branch A — Mechanism

Examiner: The referral says "severe MR for a clip". What do you need to know first?

Strong answer: The mechanism. ESC/EACTS 2025 separates primary MR, an anatomical lesion of the valve apparatus, from secondary MR, caused by LV or LA dilatation and dysfunction.^[1] It splits secondary MR into atrial and ventricular forms, which differ in prognosis and treatment.^[1] ACC/AHA 2020 puts it simply: primary MR is a disease of the valve, secondary MR a disease of the ventricle or atria.^[2]

Examiner: Is the annulus part of primary MR?

Strong answer: It depends on the guideline. ESC/EACTS 2025 limits primary MR to the leaflets, chordae and papillary muscles, explicitly excluding the annulus. ACC/AHA 2020 lists the annulus among the components.^[1][2]

Branch B — Severity

Examiner: Which numbers make primary MR severe?

Strong answer: ACC/AHA 2020 stage C or D lists six criteria. Colour flow shows a central jet over 40% of LA or a holosystolic eccentric jet, and angiographic grade is 3+ to 4+. Quantitatively, vena contracta is 0.7 cm or more, regurgitant volume 60 mL or more, regurgitant fraction 50% or more and ERO 0.40 cm² or more. Not every criterion is present in every patient; grading depends on data quality and integration of the parameters with other clinical evidence.^[2]

Examiner: And in secondary MR?

Strong answer: This is where the regions differ. ESC/EACTS 2025 says lower thresholds may apply; an EROA of 30 mm² or more and/or RVol of 45 mL or more significantly affects outcomes.^[1] ACC/AHA 2020 uses the primary-MR definition, notes the RVol cut-off may be lower in low-flow states, and warns that 2D PISA underestimates the true ERO because the proximal convergence is crescentic.^[2] Either way, grade after medical optimisation, euvolaemic and normotensive.^[1]

Branch C — Timing in asymptomatic primary MR

Examiner: She has severe primary MR, no symptoms, LVEF 62%. Why not wait?

Strong answer: LVEF is load dependent and often overestimates LV function in MR, because the LV ejects into a low-impedance atrium.^[2] In asymptomatic severe primary MR, ESC/EACTS 2025 recommends MV surgery with LVESD 40 mm or more, LVESDi 20 mm/m² or more, or LVEF 60% or less (Class I, level B).^[1] In asymptomatic patients without LV dysfunction, it recommends surgical repair in low-risk patients when a durable result is likely, if at least three criteria are present (I B).^[1] The criteria are AF, resting SPAP above 50 mmHg, LA dilatation, and secondary TR of at least moderate grade. In asymptomatic patients without LV dysfunction, either resting SPAP above 50 mmHg or AF secondary to MR on its own gives IIa B for surgery. In the same asymptomatic patients without LV dysfunction, significant LA dilatation (LAVI 60 mL/m² or more or LA diameter 55 mm or more) on its own gives IIa B for repair in low-risk patients, in a Heart Valve Centre, when a durable repair is likely.^[1]

Examiner: What evidence supports acting early?

Strong answer: In a propensity-analysed cohort of 1063 asymptomatic patients with severe degenerative MR and preserved LV function, followed for a median of 12 years, cardiovascular death was 1.5% with early surgery vs 10.4% with conventional care (HR 0.17). Repair succeeded in 97%, with no operative deaths.^[10]

Examiner: Repair or clip?

Strong answer: ESC/EACTS 2025 recommends MV repair as the surgical technique when the result is expected to be durable (I B). TEER should be considered in symptomatic patients who are anatomically suitable and at high surgical risk according to the Heart Team (IIa B).^[1] ACC/AHA 2020 notes that superior outcomes were shown with surgery versus TEER, so TEER is performed only in patients at high or prohibitive surgical risk.^[2]

Branch D — Ventricular secondary MR

Examiner: Now the real referral: LVEF 32%, LVESD 56 mm, NYHA III, severe secondary MR. Does the clip help?

Strong answer: First confirm optimised GDMT and CRT if indicated, then re-grade. About 40% of patients with ventricular SMR show improvement in SMR severity after 1–3 months of optimised GDMT.^[1] If severe MR persists, ESC/EACTS 2025 recommends TEER (Class I, level A) in haemodynamically stable, symptomatic patients with LVEF below 50%, persistent severe ventricular SMR despite optimised GDMT and CRT (if indicated), and no concomitant CAD, who meet its specific clinical and echo criteria. These include NYHA II or more, LVEF 20–50%, LVESD 70 mm or less, SPAP 70 mmHg or less, and anatomy suitable for M-TEER. They also need at least one HF hospitalisation within the previous year or raised natriuretic peptides (BNP 300 pg/mL or more, or NT-proBNP 1000 pg/mL or more). Exclusions include severe RV dysfunction, stage D HF and CAD needing revascularisation.^[1] The 2026 ESC HF guideline grades TEER Class I, level B1 for haemodynamically stable, symptomatic HFrEF patients with persistent severe secondary MR despite optimised therapy and CRT if indicated, who fulfil its Table 19 criteria. That table mirrors ESC/EACTS Table 7 and adds optimised therapy as a criterion.^[3][1] In 2021 it was Class IIa, level B, for carefully selected patients with secondary MR not eligible for surgery and not needing coronary revascularisation, who were symptomatic despite optimal medical therapy and fulfilled criteria for reducing HF hospitalisation.^[3]

Examiner: Then why was MITRA-FR negative?

Strong answer: MITRA-FR, in severe secondary MR, showed no significant difference in death from any cause or unplanned HF hospitalisation at 12 months (54.6% vs 51.3%).^[6] COAPT cut HF hospitalisation (HR 0.53) and death (HR 0.62) within 24 months.^[5] ACC/AHA 2020 notes MITRA-FR enrolled larger ventricles with less severe MR. Grayburn calls that MR proportionate to LV dilatation.^[2][7]

Examiner: What have the newer trials added?

Strong answer: RESHAPE-HF2, in heart failure with moderate-to-severe functional MR, lowered HF hospitalisation or CV death at 24 months (rate ratio 0.64) and improved the KCCQ score.^[8] ESC/EACTS 2025 notes that a meta-analysis of COAPT, MITRA-FR and RESHAPE-HF2 showed fewer HF rehospitalisations at 24 months (HR 0.63) but no significant difference in all-cause or cardiovascular death.^[1] MATTERHORN, in heart failure with secondary MR, found TEER noninferior to surgery within 1 year, with fewer major adverse events within 30 days (14.9% vs 54.8%).^[9]

Branch E — Atrial secondary MR

Examiner: A 78-year-old with persistent AF, HFpEF, LVEF 60%, a 40 mm annulus and a central jet. Same plan?

Strong answer: No. This looks like atrial secondary MR; I would check the criteria ESC/EACTS 2025 says most frequently define it. These are LVEF 50% or more without regional wall motion abnormality or tethering, no or only mildly dilated LV, annulus AP diameter above 35 mm and LAVI above 34 mL/m².^[1] Treat AF and HFpEF first; SGLT2 inhibitors are encouraged in HFpEF, and limited data suggest rhythm control may help reduce atrial SMR severity.^[1] If she is symptomatic with severe atrial SMR under optimal medical therapy, ESC/EACTS 2025 says MV surgery, surgical AF ablation if indicated, and LAAO should be considered (IIa B).^[1] If she is symptomatic with severe atrial SMR but not eligible for surgery after optimised therapy including rhythm control, when appropriate, TEER may be considered (IIb B), but planar coaptation risks a raised gradient.^[1]

Branch F — Acute presentation

Examiner: Day two after an inferior MI: flash pulmonary oedema, BP 85/50, a new murmur.

Strong answer: ESC 2023 ACS says this should raise suspicion of a mechanical complication, and immediate echocardiographic assessment is indicated.^[4] Complete papillary muscle rupture causes very severe MR, which is poorly tolerated, and the murmur may be short.^[2] For severe acute MR after infarction, medical management has the worst prognosis.^[11] ESC 2023 ACS regards surgery as the treatment of choice, with IABP considered while awaiting surgery. ESC/EACTS 2025 says papillary muscle rupture generally needs surgical valve replacement.^[1][4]

Examiner: One sentence to finish.

Strong answer: Name the mechanism, repair primary MR before the ventricle fails, and treat ventricular secondary MR as heart failure first, with TEER for the patients who meet the criteria.^[1][2][3]