Primary mitral valve regurgitation Daniela Panayotova University Hospital St. Marina Varna, Bulgaria
Normal mitral valve structure Normal mitral valves leaflets have four well-defined tissue layers, from the atrial to the ventricular aspect, these layers were the Auricularis, the Spongiosa, the Fibrosa, and the Ventricularis Each layer, containing characteristic cells and extracellular matrix, plays a different role
normal mitral valve • the average valve leaflet thickness of clear zone is 0.7–0.9 mm • percentage of the Spongiosa in relation to the valve thickness was variable but almost 10%–20%
The main pathological hallmarks in degenerative mitral valve disease • Abnormal accumulations of mucopolysaccharide in the spongiosa • Infiltration to the Fibrosa as a structural core for valve tissue • The layered architecture is destroyed • Valve thickening and structural fragility are induced • Individual collagen bundles are fragmented, coiled, disrupted • Decreased consistency is derived from the complicated structure • Similar changes are observed in chordal tendineae
The main pathological hallmarks in degenerative mitral valve disease Immune activity against extracellular matrix proteins (such as fibrin and elastin18) and collagen I and III19) • Rabkins, et al. hypothesized that activated metalloproteinase (MMP) and cathepsins secretion by valvular interstitial cells (VICs) in mitral valves mediates extracellular matrix degeneration in cases with myxomatous degeneration
Pathohistological differences betw een FED and BML proportion of the Spongiosa is 30% proportion of the Spongiosa is over 50% Histologic sections of BML . Histologic sections of FED . Mucopolysaccharide were widely infiltrating Valve tissue is usually thinner than in BML into the Spongiosa, which thickened the valve and its four-layer architecture of the leaflet in the BML group, giving the appearance of tissue is almost preserved cystic spaces
Carpentier Classification of mitral regurgitation
Two diferent mechnisms of regurgitation Prolapse – free edge of Billowing – systolic protrusion of the leaflet above the leaflet body above the annulus plane of the annulus at plane. Free edge remaining at or end-systole, disruption of below the annular plane during coaptation end-systole Lang RM, Tsang W, Weinert L, Mor-Avi V, Chandra S. J Am Coll Cardiol 2011
Classification Carpentier, et al. classified patients with degenerative mitral valve disease into two different forms on the basis of clinical patterns and gross appearance: billowing mitral leaflet (BML) Barlow’s Disease fibroelastic deficiency (FED)
Degenerative mitral valve disease is divided into several subtypes according to clinical variability Lang RM, Tsang W, Weinert L, Mor-Avi V, Chandra S. J Am Coll Cardiol 2011
Difference betw een Barlow ’s Disease and Fibroelastic Deficiency Barlow’s Disease (BML) Fibroelastic Deficiency • severely dilated annulus • localized prolapse with healthy adjacent segments • multiple segments of the leaflet(s) showed billowing into the atrial side • area of prolapse is small thickened with excess tissue • the leaflet is typically flail with a high • prolapse has a wide and low shape prolapse height as a “tower” as a “plateau” • elongation of the chords is localized in • thickened, elongated and fused a few segments chordae with occasional calcification • visible ruptured chords • Calcification of papilary muscles • in most of cases only posterior leaflet(P2) is involved • the annulus is not dilated or is only slightly dilated
Clinical characteristics of degenerative mitral valve disease FED Barlow’s Disease (BML) • elderly patients, who did not have • patients are more likely to be a long history of a murmur middle- aged, and they have a long-term evolution of mitral valve • disease duration tended to be insufficiency (10–20 years) shorter and presented frequently with ruptured chordae
Special characteristics of BML The posterior leaflet displaced toward the LA free wall away from the ventricular hinge → cul -de- sac along posterior annulus → anular fissures and calcification
Differentiation of Barlow ’s Disease From FED Using Prolapse Height, Volume Chandra S, Lang RM et al., Circ Imaging 2011
Differentiation of Barlow ’s Disease From FED Using Prolapse Height, Volume, and PV-PH Ratio FED ← 1.15ml ˃ PV ˃ 1.15ml → Barlow In some cases FED PV ˃ 1.15ml → PV-PH ratio, a novel parameter of prolapse, was able to differentiate Barlow’s disease from FED more precisely than crude prolapse volume or height PV- PH ratio Barlow ˃ 0.3 PV- PH ratio FED ˂ 0.3
Grading mitral regurgitation severity Zoghbi WA, Enriquez-Sarano M, et al. J Am Soc Echocardiogr. 2003;16:777802 .
Stages of primary mitral regurgitation Nishimura et al 2014 AHA/ACC Valvular Heart Disease Guideline
Predictors of poor outcome in primary MR Clinical characteristics Biologic markers Echo findings Low EF ˂ 60% Advance age Elevated BNP EROA ˃ 40mm² Symptoms of CHF Left atrial index ≥ 60ml/m² Atrial fibrilation Poor exercise capacity Pulmonary hypertemsion Abnormal LV strain
Outcome of Asymptomatic degenerative Mitral Regurgitation Patients with a left atrial index 40 ml/m2 have lower 2-year survival and more cardiac events than those with mild or no left atrial enlargement. In this cohort, mitral surgery is associated with decreased mortality and cardiac events. Julien Magne Heart 2012;98:584e591
Outcome of Asymptomatic degenerative Mitral Regurgitation 456 patients (mean [±SD] age, 63±14 years; 63 percent men; ejection fraction, 70±8 percent) with asymptomatic organic mitral regurgitation, quantified according to current recommendations (regurgitant volume, 66±40 ml per beat; effective regurgitant orifice, 40±27 mm 2 ). Maurice Enriquez-Sarano, M.D., N Engl J Med 2005;352:875-83 .
New biomarkers for primary mitral regurgitation • High-density lipoprotein • Apolipoprotein- A1 • Haptoglobin • Haptoglobin- α2 chain levels significantly decreased proportionally to the degree of mitral regurgitation when compared to controls
Indications for surgery for MR Nishimura et al. JACC Vol. 63, No. 22, 2014 2014 AHA/ACC Valvular Heart Disease Guideline
Identify the prolapsing scallop( more then 3 segments)
Identify the prolapsing scallop (more then 3 segments)
Identify the prolapsing scallop (more then 3 segments)
Identify the prolapsing scallop( more then 3 segments+ruptured cords)
Identify the prolapsing scallop (A2)
Identify the prolapsing scallop (A2)
Identify the prolapsing scallop (P2)
Identify the prolapsing scallop (P2)
Identify the prolapsing scallop (P3)
Indicators for stress echocardiography in primary MR • assessment of patients whose symptoms or LV dysfunction appear disproportionate to the severity of MR at rest • To define asymptomatic patients with severe MR with normal cavity dimensions and good LV function those who have a good prognosis who can avoid surgery those who are more likely to progress to symptoms and LV dysfunction who need surgery ear
Stress echocardiography for moderate MR • 40mm² ˃ ERO ˃ 20mm² • 60ml˃ RV ˃ 30ml Srtess Echo As a functional MR, degenerative MR can be dynamic with stress – induced changes One – forth of patients develop severe MR during stress ↑ ERO ≥ + 10 mm² ↑ RV ≥ + 15ml Magne et al. JACC Vol. 56, No. 4, July 20, 2010:300–9
Changes in MR (RV) RV ˃ 60ml RV ˃ 60ml 30ml ˂ RV ≤ 60ml 30ml ˂ RV ≤ 60ml RV ≤ 30 ml
Changes in MR (ERO) ERO ˃ 40mm² ERO ˃ 40 mm² 20mm² ˂ ERO ≤ 40mm² 20mm² ˂ ERO ≤ 40mm² ERO ≤ 20 mm²
Why does primary MR worsen during exercise? • changes in LV and annular geometry • papillary muscle traction, resulting in the fibrosis
Stress echocardiography - correct identification of surgical candidates ↑ ˃ 10mm² EROA ↑ ˃ 15ml RV PASP ˃ 60mmHg Peak TR maximal velocity and calculation for PASP LVEF fail to improve by ≥4% Peak LVEF GLS fail to improve by ≥ 1.9% Global longitudinal strain ↑ ≥ 90 pg /ml ( at rest ˃40 pg/ml) e BNP
Simptom-free survival Symptom-free survival of patients with marked exercise-induced increase in RV (≥ +15 ml) compared with those with marked decrease (˃ -15 ml) or no marked change (˂ +15 ml and ˃ -15 ml). Magne et al. JACC Vol. 56, No. 4, 2010
Prognostic importance of left ventricular longitudinal function in asymptomatic degenerative mitral regurgitation Julien Magne Heart 2012;98:584e591
Prognostic importance of left ventricular longitudinal function in asymptomatic degenerative mitral regurgitation reduction in GLS from rest reduction in GLS to exercise
Impact of a left Ventricular ejection index in asymptomatic primary MR LV ejection index (LVEI) = Indexed LV end−systolic diameter LVOT TVI LVEI ˃ 1.13 • an independent predictor of postoperative LV dissfunction • a powerful determinant of postoperative cardiovascular mortality
Impact of a left Ventricular ejection index in asymptomatic primary MR LVOT TVI – 17,4 cm BSA – 1.75 m² Indexed LVESD – 14.9/m² LVEI – 0.84
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