Effect of Chordal Preservation on Left Ventricular Function

The impact of complete versus partial preservation of the sub-valvular apparatus on left ventricular function in mitral valve replacement

INTRODUCTION

In mitral valve replacement (MVR), sudden increases in afterload and disruption of the annular-chordal-papillary-left-ventricular wall causes left ventricular (LV) dysfunction in the early postoperative period. Preservation of the posterior mitral leaflet apparatus (MVR-P) has a favorable outcome on LV function. However, there is paucity of data on the impact of complete preservation of the sub-valvular apparatus (MVR-C).

OBJECTIVE

We investigated the impact of MVR-P and MVR-C on baseline and 3-months postoperative LV ejection fraction (EF) and global longitudinal strain (GLS).

METHODS

We retrospectively analyzed a cohort of 29 MVR-P and 19 MVR-C patients with complete echocardiography data at our unit, who were operated between 2008 and 2017. Between-group changes in LVEF and GLS were compared using independent sample T-test.

RESULTS

Median age was 59 years (IQR 50-69 years). Baseline LVEF was 58% (51%- 60%). Baseline GLS was -18.4 (-21.2 to -15.5). There were no significant between-group differences between all baseline demographics and echocardiographic markers. There was significantly higher absolute postoperative LVEF in MVR-C patients (p = 0.029). There was also significant worsening in LVEF (p = 0.0121) and GLS (p < 0.0001) after MVR-P and not MVR-C, suggesting no reduction in LV function post-MVR-C but a reduction post-MVR-P. There was significantly less postoperative worsening of GLS per patient in MVR-C group as compared to the MVR-P group (p = 0.023), indicating better preservation of LV function. There was also a smaller decline in LVEF per patient in the MVR-C as compared to the MVR-P group, although not statistically significant (p = 0.23).

CONCLUSION

MVR with complete preservation of the sub-valvular apparatus shows a favorable impact on the longitudinal function of the heart at 3 months. Further studies with larger patient numbers are indicated to investigate the long-term results of this surgical approach.

Results and outcomes for patients with atrioventricular groove disruption after mitral valve surgery

BACKGROUND

Atrioventricular groove disruption (AVGD) is a rare and severe complication of mitral valve surgery (MVS). Current literature is limited to several case reports and series. Our aim was to analyze outcomes of patients with AVGD after MVS from our tertiary cardiac surgery center.

METHODS

Between June 2010 and January 2019, 18 patients suffering AVGD were identified in our institutional database and included in our retrospective observation. Preoperative, intraoperative and outcome data were analyzed using IBM SPSS Statistics. Late survival was estimated by using the Kaplan-Meier survival analysis.

RESULTS

The mean age of the study population was 76 ± 5 years. Most common indication for MVS was an isolated mitral valve insufficiency (67%). Severe annular calcification was present in four patients (22%). Majority of implanted valves were biological prosthesis (78%). Due to the location, 72% suffered type I rupture. External repair was performed in 94% of all patients. Second look operation in regard of excessive mediastinal hemorrhage was necessary in 67% of patients. Mean hospital stay of the presented collective was 13 ± 11 days with an intra-hospital mortality of 56%. Late follow-up was obtained in eight patients at an average of 3.1 (1.6-5.7) years postoperatively.

CONCLUSION

Mortality rates for AVGD after MVS are high. However, way of managing AVGD depends on the underlying type of rupture and should be evaluated in regard of the myocardial damage. Due to the rare occurrence, registry data might help to address more scientific value concerning therapeutic measures and outcomes of this severe complication.

Inverted aortic bioprosthetic for mitral valve replacement with Ross procedure: case report

Background

A 34-year-old gentleman presented with Staphylococcus salivarius infective endocarditis 13 years after aortic homograft and mitral valve repair for degenerative bicuspid aortic valve associated with rheumatic heart disease. The homograft had calcified, and the mitral repair had deteriorated with severe regurgitation. Multidisciplinary team decision to restore best quality of life was for re-do Ross procedure with bi-leaflet preserving mitral valve replacement with an inverted RESILIA aortic valve as the patient was fundamentally against lifelong anti-coagulation.

Case presentation

The aortic homograft was excised, and coronary arteries dissected out followed by harvesting of the pulmonary autograft. The mitral valve was accessed via a trans-septal approach. On examination, there was a restricted and thickened posterior mitral valve leaflet. An inverted 27-mm INSPIRIS RESILIA aortic bio-prosthesis was placed with mitral cusps preserved. The pulmonary autograft was implanted in an intra-annular position, and a 26-mm pulmonary homograft was used to replace the pulmonary valve. Echocardiogram at 4 weeks revealed preserved LV function and well-functioning prosthetic, autograft and homograft.

Conclusion

An inverted RESILIA valve, with its anti-structural valve deterioration properties, can be used in the mitral position with preservation of the mitral cusps to avoid anti-coagulation with the hope of reducing need for re-operation in line with patient wishes.

[Comparative assessment of immediate results of mitral valve repair according to the classical technique with posterior leaflet preservation]

We comparatively assessed the results of mitral valve repair according to the classical technique either with complete removal of leaflets or with the preservation of the posterior leaflet and the chordal-papillary apparatus. Depending on the variant of the operation, all patients were divided into two groups. Group One consisted of 23 patients in whom the posterior leaflet with the chordal-papillary apparatus was preserved, and Group Two comprised 23 patients in whom the mitral valve was removed completely. In the immediate postoperative period, Group One patients were found to have a decrease in the left ventricular end-systolic and end-diastolic dimensions and volumes. Similar dynamics was observed in relation to the left-atrial dimension, with a decrease in the pressure gradient across the mitral valve, pulmonary artery systolic pressure, and the degree of systolic shortening of the anterior-posterior size of the left ventricle. Group Two patients also demonstrated positive dynamics in relation to the left ventricular size and volume, the size of the left atrium and the right ventricle. The left-ventricular ejection fraction in the immediate postoperative period decreased averagely from 59.0±9.8% to 56.1±9.4%, accompanied and followed by a decrease in the pressure gradient across the mitral valve and pulmonary artery systolic pressure. The degree of systolic shortening of the anterior-posterior size of the left ventricle remained unchanged postoperatively. A conclusion was drawn that preserving the annulo-papillary continuity after mitral valve repair made it possible to achieve better functional results, normalization of the intracardiac haemodynamics, and improvement of the left-ventricle myocardial contractility. Complete removal of the subvalvular structures resulted in decreased contractility of the left ventricular myocardium.

Minimally invasive mitral valve repair or replacement for degenerative mitral regurgitation

OBJECTIVES

This study describes our experience with minimally invasive mitral valve (MV) repair and chordal-sparing replacement in patients with degenerative MV regurgitation.

METHODS

Between February 2009 and October 2015, a total of 960 patients underwent isolated minimally invasive MV repair, whereas 95 patients underwent chordal-sparing MV replacement. We performed a propensity score-matched analysis in 85 pairs to compare overall survival and major adverse cardiac and cerebrovascular event (MACCE) -free survival over an 8-year follow-up period. For sensitivity analyses, in the entire study cohort, we used the multivariable-adjusted Cox regression analysis to assess the overall mortality and MACCE.

RESULTS

In the propensity score-matched pairs, the 7-year probability of survival was 76.3% in the repair group and 78.8% in the replacement group (P = 0.60). Similarly, freedom from MACCE at year 7 of follow-up did not differ between the repair and replacement groups (78.6% and 72.3%, respectively; P = 0.48). The corresponding values for 7-year freedom from valve reintervention were 95.6% and 98.8%, respectively (P = 0.31). In the entire study cohort, the multivariable-adjusted hazard ratio (HR) of mortality for the replacement versus the repair group was 1.31 [95% confidence interval (CI) 0.68-2.50; P = 0.42], and the multivariable-adjusted HR of MACCE was 1.03 (95% CI 0.61-1.74; P = 0.91).

CONCLUSIONS

Our findings suggest that mid-term clinical outcomes do not significantly differ between patients undergoing MV repair or chordal-sparing MV replacement.

Bileaflet versus posterior-leaflet-only preservation in mitral valve replacement

In the present study of mitral valve replacement, we investigated whether complete preservation of both leaflets (that is, the subvalvular apparatus) is superior to preservation of the posterior leaflet alone. Seventy patients who underwent mitral valve replacement in our clinic were divided into 2 groups: MVR-B (n=16), in whom both leaflets were preserved, and MVR-P (n=54), in whom only the posterior leaflet was preserved. The preoperative and postoperative clinical and echocardiographic findings were evaluated retrospectively. No signs of left ventricular outflow tract obstruction were observed in either group. In the MVR-B group, no decrease was observed in left ventricular ejection fraction during the postoperative period, whereas a significant reduction was observed in the MVR-P group (P=0.003). No differences were found between the 2 groups in their need for inotropic agents or intra-aortic balloon pump support, or in cross-clamp time, duration of intensive care unit or hospital stays, postoperative development of new atrial fibrillation, or mortality rates. Bileaflet preservation prevented the decrease in left ventricular ejection fraction that usually followed preservation of the posterior leaflet alone. However, posterior leaflet preservation alone yielded excellent results in terms of decreased left ventricular diameter. Bileaflet preservation should be the method of choice to prevent further decreases in ejection fraction and to avoid death in patients who present with substantially impaired left ventricular function.

Importance of preservation of chordal apparatus in mitral valve replacement

Mitral valve replacement often involves disruption of the chordal apparatus with disturbance of the annulo-papillary continuity. This results in significant downgrading of ventricular function. Analyzes various reports to accurately assess the advantages of chordal preservation. This review briefly briefly reviews the surgical techniques. The advantages of chordal preservation are analyzed, with particular emphasis on the technical difficulties and potential complications involved.

Preservation versus non-preservation of mitral valve apparatus during mitral valve replacement: a meta-analysis of 3835 patients

Resection of the chordopapillary apparatus during mitral valve replacement has been associated with a negative impact on survival. Mitral valve replacement with the preservation of the mitral valve apparatus has been associated with better outcomes, but surgeons remain refractory to its use. To determine if there is any real difference in preservation vs non-preservation of mitral valve apparatus during mitral valve replacement in terms of outcomes, we performed a systematic review and meta-analysis using MEDLINE, EMBASE, CENTRAL/CCTR, SciELO, LILACS, Google Scholar and reference lists of relevant articles to search for clinical studies that compared outcomes (30-day mortality, postoperative low cardiac output syndrome or 5-year mortality) between preservation vs non-preservation during mitral valve replacement from 1966 to 2011. The principal summary measures were odds ratios (ORs) with 95% confidence interval and P-values (that will be considered statistically significant when <0.05). The ORs were combined across studies using a weighted DerSimonian-Laird random-effects model. The meta-analysis was completed using the software Comprehensive Meta-Analysis version 2 (Biostat Inc., Englewood, NJ, USA). Twenty studies (3 randomized and 17 non-randomized) were identified and included a total of 3835 patients (1918 for mitral valve replacement preservation and 1917 for mitral valve replacement non-preservation). There was significant difference between mitral valve replacement preservation and mitral valve replacement non-preservation groups in the risk of 30-day mortality (OR 0.418, P <0.001), postoperative low cardiac output syndrome (OR 0.299, P <0.001) or 5-year mortality (OR 0.380, P <0.001). No publication bias or important heterogeneity of effects on any outcome was observed. In conclusion, we found evidence that argues in favour of the preservation of mitral valve apparatus during mitral valve replacement.

Management-oriented classification of mitral valve regurgitation

Mitral regurgitation (MR) has previously been classified into rheumatic, primary, and secondary MR according to the underlying disease process. Carpentier's/Duran functional classifications are apt in describing the mechanism(s) of MR. Modern management of MR, however, depends primarily on the severity of MR, status of the left ventricular function, and the presence or absence of symptoms, hence the need for a management-oriented classification of MR. In this paper we describe a classification of MR into 4 phases according to LV function: phase I = MR with normal left ventricle, phase II = MR with normal ejection fraction (EF) and indirect signs of LV dysfunction such as pulmonary hypertension and/or recent onset atrial fibrillation, phase III = EF ≥ 30%-< 50% and/or mild to moderate LV dilatation (ESID 40-54 mm), and phase IV = EF < 30% and/or severe LV dilatation (ESDID ≥ 55 mm). Each phase is further subdivided into three stages: stage "A" with an effective regurgitant orifice (ERO) < 20 mm, stage "B" with an ERO = 20-39 mm, and stage "C" with an ERO ≥ 40 mm. Evidence-based indications and outcome of intervention for MR will also be discussed.

Does preservation of the sub-valvular apparatus during mitral valve replacement affect long-term survival and quality of life? A Microsimulation Study

BACKGROUND

Techniques to preserve the sub-valvular apparatus in order to reduce morbidity and mortality following mitral valve replacement have been frequently reported. However, it is uncertain what impact sub-valvular apparatus preservation techniques have on long-term outcomes following mitral valve replacement. This study investigated the effect of sub-valvular apparatus preservation on long-term survival and quality of life following mitral valve replacement.

METHODS

A microsimulation model was used to compare long-term survival and quality-adjusted life years following mitral valve replacement after conventional valve replacement and sub-valvular apparatus preservation. Probabilistic sensitivity analysis and alternative analysis were performed to investigate uncertainty associated with the results.

RESULTS

Our Analysis suggests that patients survive longer if the sub-valvular apparatus are preserved (65.7% SD 1.5%, compared with 58.1% SD 1.6% at 10 years). The quality adjusted life years gained over a 10 year period where also greater after sub-valvular apparatus preservation. (6.54 QALY SD 0.07 QALY, compared with 5.61 QALY, SD 0.07 QALY). The superiority of preservation techniques was insensitive to patient age, parameter or model uncertainty.

CONCLUSION

This study suggests that long-term outcomes may be improved when the sub-valvular apparatus are preserved. Given the lack of empirical data further research is needed to investigate health-related quality of life after mitral valve replacement, and to establish whether outcomes differ between preservation techniques.