Reparación mitral de la insuficiencia mitral isquémica con anillo Carpentier-McCarthy-Adams IMR ETlogix®: resultados ecocardiográficos a medio plazo

Ischemic Mitral Regurgitation: A Multifaceted Syndrome with Evolving Therapies

Dysfunction of the left ventricle (LV) with impaired contractility following chronic ischemia or acute myocardial infarction (AMI) is the main cause of ischemic mitral regurgitation (IMR), leading to moderate and moderate-to-severe mitral regurgitation (MR). The site of AMI exerts a specific influence determining different patterns of adverse LV remodeling. In general, inferior-posterior AMI is more frequently associated with regional structural changes than the anterolateral one, which is associated with global adverse LV remodeling, ultimately leading to different phenotypes of IMR. In this narrative review, starting from the aforementioned categorization, we proceed to describe current knowledge regarding surgical approaches in the management of IMR.

Are recurrence of ischemic mitral regurgitation and left ventricular reverse remodeling after restrictive annuloplasty ring dependent?

OBJECTIVE

This meta-analysis investigates MR recurrence and degree of left ventricular reverse remodeling (LVRR) in CIMR patients in mitral annuloplasty employing different ring designs.

BACKGROUND

The deeper understanding of complex changes caused by chronic ischemic mitral regurgitation (CIMR) have led to new generations of rings that, by maintaining normal 3D annular geometry are supposed to enhance long-term repair durability.

METHODS

A meta-analysis of all available reports in literature of MV repair through different ring design was conducted. Meta-regression was performed to investigate the impact of mitral ring characteristics related to flexibility, planarity, symmetry and single type utilized. Twenty studies encompassing a total of 1876 patients were included at the end of the selection process.

RESULTS

At meta-regression recurrence of MR was not influenced by the ring employed. Nonetheless, the event rate of MR recurrence in planar rings was 19%. Vs. 11% observed with non-planar rings. Recurrence rate in patients implanted with symmetric rings was 14% whereas it was 7% in asymmetric rings. The non-planar asymmetric IMR-ETlogix showed the lowest recurrence rate (6%). Furthermore, in planar group the reduction of pre- and post-operative LVEDD was - 4%. In the non-planar group, the LVEDD was reduced by 8.6%. In patients implanted with symmetric rings LVEDD reduction was 10.8%. LVRR in the asymmetric group was -5.8%.

CONCLUSION

MR recurrence occurred the least with asymmetric rings with less disproportionate asymmetry. In contrast, LVRR occurred at a greater extent in symmetric rings.

Do annuloplasty rings designed to treat ischemic/functional mitral regurgitation alter left-ventricular dimensions in the acutely ischemic ovine heart?

OBJECTIVE

To quantify the effects of annuloplasty rings designed to treat ischemic/functional mitral regurgitation on left ventricular septal-lateral (S-L) and commissure-commissure (C-C) dimensions.

METHODS

Radiopaque markers were placed as opposing pairs on the S-L and C-C aspects of the mitral annulus and the basal, equatorial, and apical level of the left ventricle (LV) in 30 sheep. Ten true-sized Carpentier-Edwards Physio (PHY), Edwards IMR ETlogix (ETL), and GeoForm (GEO; all from Edwards Lifesciences, Irvine, Calif) annuloplasty rings were inserted in a releasable fashion. After 90 seconds of left circumflex artery occlusion with the ring implanted (RING), 4-dimensional marker coordinates were obtained using biplane videofluoroscopy. After ring release, another data set was acquired after another 90 seconds of left circumflex artery occlusion (NO RING). S-L and C-C diameters were computed as the distances between the respective marker pairs at end-diastole. Percent change in diameters was calculated between RING versus NO RING as 100 × (diameter in centimeters [RING] - diameter in centimeters [NO RING])/diameter in centimeters [NO RING]).

RESULTS

Compared with NO RING, all ring types (PHY, ETL, and GEO) reduced mitral annular S-L dimensions by -20.7 ± 5.6%, -26.8 ± 3.9%, and -34.5 ± 3.8%, respectively. GEO reduced the S-L dimensions of the LV at the basal level only by -2.3 ± 2.4%, whereas all other S-L dimensions of the LV remained unchanged with all 3 rings implanted. PHY, ETL, and GEO reduced mitral annular C-C dimensions by -17.5 ± 4.8%, -19.6 ± 2.5, and -8.3 ± 4.9%, respectively, but none of the rings altered the C-C dimensions of the LV.

CONCLUSIONS

Despite radical reduction of mitral annular size, disease-specific ischemic/functional mitral regurgitation annuloplasty rings do not induce relevant changes of left ventricular dimensions in the acutely ischemic ovine heart.

Mid-term results of mitral valve repair for ischemic mitral regurgitation with ETlogix ring: A single-center study

BACKGROUND

Ischemic mitral regurgitation (IMR) is a common complication of coronary artery disease and represents an independent predictor of mortality. In the IMR the pattern of mitral valve annular dilatation is asymmetrical: this can explain the long-term incidence of recurrent mitral regurgitation after surgical annular size reduction with a symmetrical ring. The aim of this study is to analyze early and mid-term results of mitral valve repair (MVR) with the CMA IMR ETlogix ring, specifically developed for the surgical correction of IMR.

METHODS

Retrospectively, we studied 157 consecutive patients who underwent MVR with the CMA ETlogix ring for the treatment of grade ≥2 IMR in our center between June 2006 and December 2012. We reported clinical and echocardiographic early and mid-term results of this surgical technique.

RESULTS

Postoperative 30days mortality was 6.3%. Postoperative echocardiography evaluation at discharge revealed the absence of residual MR in 70%, mild MR in 26.5% and moderate MR in 3.5% of patients respectively. Median echographic follow-up time was 28 (3-84) months: survival rate was 92.1% at 32months; free from mitral valve reoperation rate was 97.5% and grade >2 MR recurrence free survival rate was 96.6%.

CONCLUSION

There are a few reports in the literature concerning the mid-term results of IMR surgical correction with CMA Etlogix ring. Our study, taking into account a large series of patients and an important follow-up period, demonstrates the effectiveness of this surgical repair technique reporting a low mid-term incidence of recurrent MR.

[Echocardiographic predictors of exercise capacity in patients with heart failure and systolic dysfunction: role of mitral regurgitation]

INTRODUCTION AND OBJECTIVES

Patients with heart failure and similar left ventricular systolic dysfunction have differing exercise capacity. The aim of this study was to identify echocardiographic predictors of exercise capacity in patients with heart failure and systolic dysfunction.

METHODS

We included 150 patients with class II (70%) or III (30%) heart failure with left ventricular ejection fraction below 40%. Six-minute walking test and cardiac color Doppler-echo, including tissue Doppler of mitral and tricuspid rings, were performed. Moderate and severe mitral regurgitation were considered as significant. Two groups were divided according to the median walking distance (290 m): Group 1, <290 m and Group 2, ≥290 m.

RESULTS

Mitral regurgitation was detected in 112 patients (75%), which was significant in 40 (27%). Group 1 showed more significant mitral regurgitation (35 vs 18%), increased left atrium area (27±1 vs 24±1cm(2)), mitral E amplitude (88±5 vs 72±3cm/s) and systolic pulmonary pressure (37±1 vs 32±1mmHg, all P<.05). By logistic regression analysis, only the presence of significant mitral regurgitation was independently associated with less walked distance (odds ratio: 3.44 95% confidence interval 1.02-11.66, P<.05). By multiple linear regression, the only independent predictor of walked distance was left atrium area (r=0.25, beta coefficient: -6.52±2, P<.01).

CONCLUSIONS

In patients with class II-III heart failure and left ventricular systolic dysfunction, the main echocardiographic predictors of exercise capacity are related to the presence of significant mitral regurgitation.