Mechanism of recurrent/persistent ischemic/functional mitral regurgitation in the chronic phase after surgical annuloplasty: importance of augmented posterior leaflet tethering.
ABSTRACT Surgical annuloplasty can potentially hoist the posterior annulus anteriorly, exaggerate posterior leaflet (PML) tethering, and lead to recurrent ischemic/functional mitral regurgitation (MR). Characteristics of leaflet configurations in late postoperative MR were investigated.
In 30 patients with surgical annuloplasty for ischemic MR and 20 controls, the anterior leaflet (AML) and PML tethering angles relative to the line connecting annuli, posterior and apical displacement of the coaptation and the MR grade were measured by echocardiography before, early after, and late after surgery. Early after surgery, grade of MR and AML tethering generally decreased (P<0.01), whereas PML tethering significantly worsened (P<0.01). Nine of the 30 patients showed recurrent/persistent MR late after surgery. Compared with patients without late MR, those with the MR showed similar reduction in the annular area, significant re-increase in posterior displacement of the coaptation, and progressive worsening in PML tethering (P<0.05) late after surgery in comparison to the early phase. Both preoperative MR and late postoperative MR were significantly correlated with all tethering variables in univariate analysis. Although apical displacement of the coaptation was the primary determinant of preoperative MR (r2=0.60, P<0.0001), increased PML tethering was the primary determinant of late MR (r2=0.75, P<0.0001).
Whereas both leaflets tethering is related to preoperative ischemic MR, both leaflets tethering but with predominant contribution from augmented and progressive PML tethering is related to recurrent/persistent ischemic/functional MR late after surgical annuloplasty.
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ABSTRACT: Attention towards the optimization of mitral valve repair methods is increasing. Patch augmentation is one strategy used to treat functional ischemic mitral regurgitation (FIMR). The study aim was to investigate the force balance changes in specific chordae tendineae emanating from the posterior papillary muscle in a FIMR-simulated valve, following posterior leaflet patch augmentation. Mitral valves were obtained from 12 pigs (body weight 80 kg). An in vitro test set-up simulating the left ventricle was used to hold the valves. The left ventricular pressure was regulated with water to simulate different static pressures during valve closure. A standardized oval pericardial patch (17 x 29 mm) was introduced into the posterior leaflet from mid P2 to the end of the P3 scallop. Dedicated miniature transducers were used to record the forces exerted on the chordae tendineae. Data were acquired before and after 12 mm posterior and 5 mm apical posterior papillary muscle displacement to simulate the effect from one of the main contributors of FIMR, before and after patch augmentation. The effect of displacing the posterior papillary muscle induced tethering on the intermediate chordae tendineae to the posterior leaflet, and resulted in a 39.8% force increase (p = 0.014). Posterior leaflet patch augmentation of the FIMR valve induced a 31.1% force decrease (p = 0.007). There was no difference in force between the healthy and the repaired valve simulations (p = 0.773). Posterior leaflet patch augmentation significantly reduced the forces exerted on the intermediate chordae tendineae from the posterior papillary muscle following FIMR simulation. As changes in chordal tension lead to a redistribution of the total stress exerted on the valve, patch augmentation may have an adverse long-term influence on mitral valve function and remodeling.The Journal of heart valve disease 01/2013; 22(1):28-35. · 1.07 Impact Factor
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ABSTRACT: Dilated cardiomyopathy (DCM) is often complicated by the appearance of functional mitral regurgitation (FMR). Although mitral ring annuloplasty (MAP) is the most widely used surgical procedure for the surgical treatment of FMR, there are still reports of patients who suffer recurrent FMR at later follow-ups. We sought to investigate the efficacy of papillary muscle approximation (PMA) combined with MAP in preventing the recurrence of FMR in high-risk patients. One hundred patients with ischaemic (74%) or non-ischaemic (26%) DCM along with severe (4+/4+) or moderately severe (3+/4+) FMR were enrolled in this prospective, cross-sectional study. According to the interpapillary muscle distance (iPMD) and coaptation depth (CD), the patients were risk stratified as low (iPMD + CD 30 mm, n= 69) and high-risk (iPMD + CD > 30 mm, n= 31) groups. The low-risk patients underwent only MAP, whereas the high-risk patients underwent MAP plus PMA. After a mean +/- SD follow-up of 40.8 +/- 12.5 months, recurrence of 3+ to 4+ MR was observed in 8 (8.7%) and 7 (11.1%) patients in the annuloplasty group (MAP-only) and one (3.4%) patient in the combination group (MAP plus PMA) (P= 0.428). At the final follow-up, the New York Heart Association (NYHA) function class was 1.57 +/- 0.62 in the annuloplasty group and 1.45 +/- 0.57 in the combination group; there was no significant difference in NYHA function class between the first and final follow-ups (P> 0.05). iPMD is a valuable index in the riskstratification of the recurrence of post-MAP MR in patients with DCM complicated by FMR.The patients treated with MAP plus PMA had more favourable outcomes and lower recurrence rates than those treated via the traditional route of MAP only.Acta cardiologica 06/2013; 68(3):271-8. · 0.61 Impact Factor
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ABSTRACT: Ischemic mitral regurgitation (MR) results from ischemic left ventricular distortion with tethering of the mitral leaflets. The standard surgical therapy for ischemic MR is mitral ring annuloplasty, often performed at the time of coronary artery bypass surgery. However, ring annuloplasty is associated with an up to 30% recurrence rate of MR, as it does not directly address ventricular distortion and tethering of the mitral leaflets and there is often further ventricular remodeling following bypass surgery. This article reviews the background and mechanism of ischemic MR and unusual approaches to this important yet difficult to treat valvular problem. KeywordsMitral regurgitation-LV remodelingCurrent Cardiovascular Imaging Reports 04/2012; 3(6):396-402.