Association of Mean Pressure Gradient, Pressure Half Time, Regurgitant Area, and Heart Rate with Mitral Valve Orifice Area Prior and Post Edge-To-Edge Mitral Valve Repair

This project aims to investigate the performance of edge-to-edge mitral valve repair (MVR) within reanimated swine hearts. Direct imaging and hemodynamic data of the mitral valve during normal cardiac function (Normal), after an induced prolapse (Prolapse), and post surgical repair (E2E) was obtained. Isolated swine hearts (n=6) were reanimated using a clear Krebs–Henseleit buffer. Mitral prolapse, and regurgitation, in the P2 region was induced by cutting chordae tendinae of the posterior leaflet. An edge-to-edge MVR procedure was performed, suturing the prolapsed P2 region to the A2 region of the anterior leaflet. The mitral valve was imaged using endoscopic cameras in the left atrium and ventricle allowing verification of stitch placement and leaflet coaptation. Analysis of the endoscopic images provided measures of annulus area, orifice area, and regurgitant area. Echocardiography, the standard clinical imaging modality, was used to determine the hemodynamic performance of the valve. Additionally, ECG and left chamber pressures were recorded at a sample rate of 5 kHz. Prolapse of the P2 region was consistently created, and edge-to-edge repair of the mitral leaflet showed full leaflet coaptation. The annulus area of the valve was tracked throughout the procedure and did not show significant variation. The orifice area, defined as the area of the annulus that does not contain leaflets, normalized to the corresponding annulus area for Normal, Prolapse and E2E were: 41±13%, 44±14% and 21±13%, p=0.02. The regurgitant area, normalized to the corresponding annulus area, increased from 2±2% for Normal to 8±3% for the Prolapse and then decreased to 1±1% for the E2E group. The regurgitant fraction, normalized against the maximum observed, for Normal, Prolapse and E2E was 10±6%, 57±26% and 13±13%, p<0.01. Over the course of the experiment the left ventricular (LV) systolic pressure and negative dP/dt reduced from 95 to 54 mm Hg and 743 to 402 mm Hg/s, respectively. Our results show that orifice area was significantly smaller after MVR when compared to Normal and Prolapse periods. There was no significant change in regurgitant area and regurgitant fraction from the Normal to repaired valve as compared to a significant increase in regurgitant area and regurgitant fraction during Prolapse. Low gradients were observed for all three groups, with no indications for symptomatic stenosis. The reduction of LV function was caused by global ischemia and the progressive onset of edema. In this acute assessment of edge-to-edge repair of P2 prolapse, repair does not affect annulus area, decreases orifice area, and successfully eliminates regurgitant area with no evidence of mitral stenosis.

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Determination of mitral valve area with echocardiography, using intra-operative 3-dimensional versus intra- & post-operative pressure half-time technique in mitral valve repair surgery

Journal of Cardiothoracic Surgery ◽

10.1186/1749-8090-8-98 ◽

2013 ◽

Vol 8 (1) ◽

Cited By ~ 3

Author(s):

Woon-Seok Kang ◽

Jae Won Choi ◽

Joo-Eun Kang ◽

Jin Woo Chung ◽

Seong-Hyop Kim

Keyword(s):

Mitral Valve ◽

Mitral Valve Repair ◽

Half Time ◽

Valve Repair ◽

3 Dimensional ◽

Mitral Valve Area ◽

Valve Area

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Measurement of mitral valve orifice area in infants and children by two-dimensional echocardiography

Journal of the American College of Cardiology ◽

10.1016/s0735-1097(83)80202-2 ◽

1983 ◽

Vol 1 (3) ◽

pp. 873-878 ◽

Cited By ~ 19

Author(s):

Thomas W. Riggs ◽

Gregory D. Lapin ◽

Milton H. Paul ◽

Alexander J. Muster ◽

Teresa E. Berry

Keyword(s):

Mitral Valve ◽

Infants And Children ◽

Two Dimensional ◽

Orifice Area ◽

Valve Orifice ◽

Dimensional Echocardiography ◽

Two Dimensional Echocardiography ◽

Valve Orifice Area ◽

In Infants And Children

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Long-Term survival and functional status in patients with elevated mitral valve pressure gradient after transcatheter mitral valve repair

European Heart Journal ◽

10.1093/eurheartj/ehab724.1641 ◽

2021 ◽

Vol 42 (Supplement_1) ◽

Author(s):

B Koell ◽

S Ludwig ◽

J Weimann ◽

L Waldschmidt ◽

N Schofer ◽

...

Keyword(s):

Mitral Valve ◽

Pressure Gradient ◽

Functional Outcome ◽

Mitral Valve Repair ◽

Cox Regression ◽

Valve Repair ◽

Transcatheter Mitral Valve Repair ◽

Kaplan Meier ◽

Valve Pressure

Abstract Background A growing number of patients are currently treated for severe mitral regurgitation (MR) using a transcatheter mitral valve repair (TMVr). In clinical routine, the potential risk of elevated post-procedural mitral valve pressure gradient (MPG) may prohibit optimal MR reduction driven by the avoidance of additional clip implantations. Thus, the unfavorable impact on survival and functional outcome of increased MPG in patients undergoing TMVr is currently debatable. Methods In this single-center, prospective study, survival and functional outcome of 780 consecutive patients with severe MR undergoing TMVr between September 2008 and January 2020 were investigated. After exclusion of patients with unsuccessful procedure and those lost to follow-up, data of 676 patients with a median follow-up time of 5.26 (5.11, 5.51) years were analyzed. MPG was determined by transthoracic echocardiography at discharge and considered elevated in excess of 4.5 mmHg. Kaplan-Meier analysis as well as multivariable Cox regression models were performed for the impact on elevated MPG on 5-year outcomes for the subgroups of functional MR (FMR) and degenerative MR (DMR). The primary outcome measure was a combined endpoint of death or rehospitalization for congestive heart failure. Results Among 676 patients undergoing TMVr (mean age 74.6±8.5 years, 59.0% male, median STS Score 3.9 [interquartile range 2.5; 6.0]), 179 (26.4%) patients had elevated MPG >4.5 mmHg. FMR was present in 426 (63.0%) patients. In the overall patient cohort, Kaplan-Meier and Cox Regression analyses could not demonstrate significant differences for the combined endpoint (p=0.99). In contrast, subgroup analysis according to MR etiology indicated a significant adverse influence of elevated MPG on the combined endpoint as well as functional outcome in patients with DMR, but not with FMR (Figure 1). After adjustment, multivariate Cox Regression analysis showed an inferior prognosis in patients with DMR and elevated MVPG >4.5 mmHg (hazard ratio 1.79 [1.17, 2.72], p=0.0069, Figure 2). Conclusions TMVr-patients with DMR and measurable elevated post-procedural MVPG face an inferior prognosis and reduced functional outcomes compared to patients with FMR. FUNDunding Acknowledgement Type of funding sources: None. Figure 1 Figure 2

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Effects of atrial fibrillation and heart rate on percutaneous mitral valve repair with MitraClip: results from the TRAnscatheter Mitral valve Interventions (TRAMI) registry

EuroIntervention ◽

10.4244/eij-d-16-00115 ◽

2017 ◽

Vol 12 (14) ◽

pp. 1697-1705 ◽

Cited By ~ 20

Author(s):

Alexander Jabs ◽

Ralph von Bardeleben ◽

Peter Boekstegers ◽

Miriam Puls ◽

Edith Lubos ◽

...

Keyword(s):

Atrial Fibrillation ◽

Heart Rate ◽

Mitral Valve ◽

Mitral Valve Repair ◽

Valve Repair ◽

Percutaneous Mitral Valve Repair

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Abstract 16560: Impact of Assuming a Circular Orifice on Flow Error Through Elliptical Regurgitant Orifices: A Computational Fluid Dynamics (CFD) Analysis

Circulation ◽

10.1161/circ.132.suppl_3.16560 ◽

2015 ◽

Vol 132 (suppl_3) ◽

Author(s):

Sumeet S Mitter ◽

Gregory J Wagner ◽

Alex J Barker ◽

Michael Markl ◽

James D Thomas

Keyword(s):

Mitral Valve ◽

Hydrodynamic Theory ◽

Axis Ratio ◽

Orifice Area ◽

Proximal Isovelocity Surface Area ◽

Valve Orifice ◽

Circular Orifice ◽

Flow Through ◽

Valve Orifice Area

Introduction: Hydrodynamic theory predicts fluid approaches a point orifice with accelerating velocity in hemispheric shells, forming the basis for the proximal isovelocity surface area (PISA) method to quantify valve regurgitation. Previous CFD and in vitro work has shown that with a finite, non-point orifice, there is a small, systematic underestimation of flow that is approximately the ratio of contour velocity (va) to maximal orifice velocity (vo), e.g., roughly an 8% error if a 40 cm/s contour is used with a 5 m/s jet. The PISA method is further questioned in the setting of noncircular orifices, with concerns of further underestimation. We sought to quantify this impact with CFD. Hypothesis: Application of standard PISA analysis to an elliptical orifice leads to further flow underestimation, but the magnitude is negligible. Methods: Mathematical modeling of flow through a finite elliptical orifice was computed using the open-source incompressible flow solver Nalu. Forty-five permutations of valve flow were characterized by varying valve orifice area (0.1, 0.3 and 0.5 cm^2), ellipse axis ratios (1:1, 2:1, 3:1, 5:1, and 10:1), and max velocity (400, 500 and 600 cm/s). Computed hemispherical flow contours scaled to true orifice flow (Qc/Qo) and scaled computed area to true orifice area (Ac/Ao) were plotted against distance from the orifice scaled to a circular orifice with equivalent orifice area. Results: Qc/Qo and Ac/Ao for each ellipse axis ratio when plotted against normalized orifice distance produced the same curves for each permutation of valve orifice area and max velocity. Plotting Qc/Qo (or Ac/Ao) against va/vo reveals marginal underestimation of flow with physiologic elliptical axis ratios of 2:1 and 3:1 against a circular orifice with axis ratios of 1:1 (Figure 1). Conclusions: The added error in using PISA to approximate flow through an elliptical mitral valve orifice area is minimal compared to traditional assumptions of a circular mitral valve orifice.

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Edge-to-edge transcatheter valve repair of atrial functional mitral regurgitation positively influences atrial pathology

European Heart Journal ◽

10.1093/eurheartj/ehab724.2213 ◽

2021 ◽

Vol 42 (Supplement_1) ◽

Author(s):

A Petrescu ◽

M Geyer ◽

T Ruf ◽

O Hahad ◽

A Tamm ◽

...

Keyword(s):

Mitral Valve ◽

Mitral Regurgitation ◽

Mitral Valve Repair ◽

Nyha Class ◽

Systolic Dysfunction ◽

Left Ventricular ◽

Functional Mitral Regurgitation ◽

Valve Repair ◽

Transcatheter Mitral Valve Repair ◽

Mean Pressure

Abstract Introduction Functional mitral regurgitation (FMR) is the result of an insufficient coaptation of the mitral valve leaflets lacking relevant degeneration or morphological alterations of the valve apparatus. In most patients, this is caused by left ventricular (LV) systolic dysfunction and remodelling (ischemic or non-ischemic). However, a small subset of FMR patients is seen in the context of left atrial (LA) enlargement due to isolated atrial dilation in the absence of a ventricular pathology and has been termed “atrial functional MR” (AFMR) as a distinct etiology of FMR. The effect of transcatheter mitral valve repair (TMVR) by edge-to-edge-repair (e.g., MitraClip®) on AFMR reduction has not been studied, but it is considered to be effective regarding its effect on the anterior-posterior mitral annular diameter. Methods We retrospectively screened all 737 patients treated with TMVR by edge-to-edge repair in our center between January 2013 and April 2019. AFMR was defined as FMR with: (1) relevant LA dilatation, (2) no LV systolic dysfunction or (3) dilatation, (4) no ischemic etiology of FMR. LA mean pressure was invasively measured peri-interventionally before and after device implantation. Echocardiographic assessment was repeated at 1 year follow-up (1yFUP). Results Among 350 patients (47.5%) with FMR, 57 patients (16.3%) met the inclusion criteria for AFMR and were included in the data analysis. All patients in the AFMR group (mean age 81.4±5.7 years, 78.9% female) were symptomatic (82.2% functional NYHA class≥III) at baseline and were assessed to be at elevated risk for surgery (mean logistic EuroScore of 24.8±12.0%). TVMR was successfully performed in all patients without any peri-interventional major complications. At hospital discharge, 78.3% of patients had mild residual MR and 17.4% had no detectable MR. At 1 year, the echocardiographic prevalence of residual moderate MR was 11.4% and 2.9% of patients had severe MR (Figure A). Invasive LA mean pressure measurements were available in 39 patients (68.4%). In average, LA mean pressures decreased from 18.8 mmHg to 12.8 mmHg (p<0.001). Analysis at 1yFUP showed a significant reduction in LA volume, both at end-systole (79.6±31.9 vs. 66.9±31.8 ml/m2 p<0.001; Figure B) and at end-diastole (61.6±21.5 vs. 50.4±27.37 ml/m2; p<0.01; Figure C). LA ejection fraction increased from 18.8%±12.6% to 30.1%±12.3% in 54.8% of patients. These findings were accompanied by a relevant symptomatic benefit (NYHA class I/II was found in 66.7% of patients at 1 year). Conclusions Transcatheter mitral valve repair by edge-to-edge therapy in symptomatic patients with atrial functional mitral regurgitation is safe and capable of a relevant reduction of mitral regurgitation severity accompanied by symptomatic improvement and positive atrial remodeling. FUNDunding Acknowledgement Type of funding sources: None.

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