Standardized subannular repair for type IIIb functional mitral regurgitation in a minimally invasive mitral valve surgery setting†

Anatomic, stage-based repair of secondary mitral valve disease

OBJECTIVE

Intervention for repair of secondary mitral valve disease is frequently associated with recurrent regurgitation. We sought to determine if there was sufficient evidence to support inclusion of anatomic indices of leaflet dysfunction in the management of secondary mitral valve disease.

METHODS

We performed a systematic review and meta-analysis of published reports comparing anatomic indices of leaflet dysfunction with the complexity of valve repair and the outcome from intervention. Patients were stratified by the severity of leaflet dysfunction. A secondary analysis was performed comparing outcomes when procedural complexity was optimally matched to severity of leaflet dysfunction and when intervention was not matched to dysfunction.

RESULTS

We identified 6864 publications, of which 65 met inclusion criteria. An association between the severity of leaflet dysfunction and the procedural complexity was highly predictive of satisfactory freedom from recurrent regurgitation. Patients were categorized into 4 groups based on stratification of leaflet dysfunction. Satisfactory results were achieved in 93.7% of patients in whom repair complexity was appropriately matched to severity of leaflet dysfunction and in 68.8% in whom repair was not matched to dysfunction (odds ratio, 0.148; 95% confidence interval, 0.119-0.184; P < .0001).

CONCLUSIONS

For patients with secondary mitral valve disease, satisfactory outcome from valve repair improves when procedural complexity is matched to anatomic indices of leaflet dysfunction. Anatomic indices of leaflet dysfunction should be considered when planning interventions for secondary mitral regurgitation. Routine inclusion of anatomic indices in trial design and reporting should facilitate comparison of results and strengthen guidelines. There are sufficient data to support anatomic staging of secondary mitral valve disease.

Subannular repair for functional mitral regurgitation with reduced systolic ventricle function: rationale and design of REFORM-MR registry

BACKGROUND

Functional mitral regurgitation (FMR) is one of the most common heart valve diseases that is a sequel of left ventricular remodelling. Although mitral valve annuloplasty is a standard treatment of FMR, the recurrence of FMR is a major drawback and occurs in 10-50% of patients. The REFORM-MR registry aims to investigate the effectiveness of standardized papillary muscle relocation and ring annuloplasty and to identify the risk factors associated with recurrent FMR.

METHODS

REFORM-MR is a prospective, multicenter registry that enrols consecutive FMR patients across five sites in Germany. All patients with FMR and restricted movement of leaflets during systole (i.e., type IIIb mitral regurgitation) undergoing standardized subannular repair in combination with mitral valve annuloplasty are included in the study. The primary objective is to examine the effect of combined papillary muscle relocation and ring annuloplasty on the recurrence of FMR at 2 years postoperatively. The secondary objectives are MACCE rate, reinterventions on the mitral valve and cardiac-related mortality in the study cohort. Echocardiography core-lab and MRI core-lab will provide anonymized analysis of the imaging data in the REFORM-MR registry. Student's t-test or Mann-Whitney U test for continuous variables and the Chi-Square or Fisher exact test for categorical variables are used for group comparisons. Kaplan-Meier analyses is performed for survival and safety outcomes.

RESULTS

As of May 2021, a total of 97 patients were enrolled across five sites in Germany.

CONCLUSIONS

The results of this study will help define the outcomes of combined papillary muscle relocation and ring annuloplasty in the FMR treatment in a multicentre setting and to improve the understanding of the limitations of subannular repair procedures while treating patients with type III FMR. Trial registration clinicaltrials.gov Identifier: NCT03470155.

Early Outcomes of Endoscopic Papillary Muscle Relocation for Secondary Mitral Regurgitation Type IIIb in Patients With Severe Left Ventricular Dysfunction

Objective: Subannular mitral valve (MV) repair techniques have been developed to address increased rates of recurrent mitral regurgitation (MR) in patients with secondary MR (SMR) type IIIb. Endoscopic papillary muscle relocation (PMR) is feasible via minithoracotomy. Nevertheless, the periprocedural outcome of patients with severe left ventricular (LV) dysfunction remains unknown. Methods: A total of 98 consecutive patients with SMR type IIIb underwent PMR at our institution. Due to concomitant coronary artery bypass grafting, 62 patients underwent sternotomy and were excluded from the current analysis, whereas 36 patients were treated by a minimally invasive technique using 3-dimensional endoscopy. Of these, 18 patients had severely depressed LV ejection fraction (LVEF) ≤35% (study group) and were compared to the remaining 18 patients with LVEF >35% (control group). Periprocedural outcome was retrospectively analyzed. Results: Although LVEF was significantly worse in the study group (30% ± 4% vs 43% ± 6%, P < 0.001), the severity of SMR and the degree of MV leaflet tethering were similar. The prevalence of concomitant procedures and the duration of surgery, cardiopulmonary bypass, and aortic cross-clamp were comparable. Periprocedural low cardiac output syndrome was favorably low in both groups (16.7% vs 5.6%, P = 0.29). Postoperative ventilation time (5.7 h [4.2 to 8.7 h] vs 6.0 h [4.6 to 9.8 h], P = 0.43) and duration of intensive care unit stay (2 days [1 to 3 days] vs 2 days [1 to 3 days], P = 0.22) were similar. There was no 30-day mortality in either group. Conclusions: Standardized endoscopic PMR resulted in favorable periprocedural outcomes in patients with severe LV dysfunction, suggesting that minimally invasive surgery can safely be extended to this patient population.

Standardized papillary muscle relocation for type IIIb secondary mitral regurgitation improves two-year outcome

OBJECTIVES

The major drawback of isolated annuloplasty for treatment of secondary mitral regurgitation (SMR) with restricted leaflet motion during systole (type IIIb) is recurrence of SMR, leading to adverse clinical outcome. Additional papillary muscles relocation (PMR) specifically addresses leaflet tethering to restore mitral valve geometry. We aimed to compare the two-year outcome of annuloplasty with additional PMR vs isolated annuloplasty.

METHODS

A total of 105 consecutive type IIIb SMR patients with preoperative LVEF <45%, LVEDD >55mm and a tenting height >10mm, reached two-year postoperative follow-up after MV repair and were included in the current analysis. 51 patients underwent annuloplasty and additional PMR (study group). 54 patients underwent isolated annuloplasty (control group). Primary composite study end-point comprised death or recurrence of MR ≥2 at two years postoperatively.

RESULTS

Echocardiographic baseline variables indicating the severity of left ventricular (LV) dysfunction and mitral leaflet tethering were similar. Procedural and periprocedural outcome was comparable in both groups. The primary composite end-point was significantly improved in the study group 19.6% [10/51] in comparison to the control group 44.4% [24/54] (p = 0.009). 2-year all-cause mortality was 7.8% [4/51] in the study group, vs 18.5% [10/54] in the control group (p = 0.098). After two years, significant improvement of NYHA functional class as compared to the baseline values was observed in the study group.

CONCLUSIONS

Additional PMR to treat SMR type IIIb resulted in an improved 2-year outcome in comparison to isolated annuloplasty. PMR specifically addressing mitral leaflet tethering represents a valid therapeutic option for heart-failure patients with SMR type IIIb.

Prognostic impact of functional mitral regurgitation prior to left ventricular assist device implantation

BACKGROUND

Functional mitral regurgitation (FMR) is a common finding of advanced heart failure with detrimental effects. The prognostic impact of uncorrected FMR prior to left ventricular assist device (LVAD) implantation remains controversial.

METHODS

Between 2016 and 2019 77 patients underwent continuous-flow LVAD implantation at our institution. 34 patients showed FMR ≥ 2 (MR-group), whereas 43 patients showed FMR < 2 (Control-group). Data was retrospectively analyzed. Primary composite endpoint comprised freedom from death, stroke, pump-thrombosis, major bleeding and right heart failure (RHF) after 1 year.

RESULTS

Baseline characteristics, including the severity of left and right ventricular dysfunction, and periprocedural results were comparable. The overall survival during a mean follow up of 24.9 months was 55.9% in the MR-group versus 58.1% in the Control-group (p = 0.963), whereas 1-year event-free survival was 35.3% in the MR-group compared to 44.2% in the Control-group (p = 0.404). RHF within the first postoperative year occurred more frequently in the MR-group (35.3% vs. 11.6%; p = 0.017). Furthermore, RV function was significantly reduced in comparison to baseline values in the MR-group. 12 months after surgery, 74% of patients in the MR-group were classified as NYHA III in comparison to 24% of patients in the Control-group (p < 0.001).

CONCLUSIONS

Preoperative uncorrected FMR prior to LVAD implantation did not affect overall survival, nevertheless it was associated with an impaired RV function and increased incidence of right heart failure during follow-up. Furthermore, preoperative FMR ≥ 2 was associated with persistent symptoms of heart failure.

Subannular repair for functional mitral regurgitation type IIIb in patients with ischaemic versus dilated cardiomyopathy

OBJECTIVES

Functional mitral regurgitation (FMR) is a sequel of left ventricular (LV) remodelling in heart failure patients. Relocation of both papillary muscles aims to specifically address mitral leaflet tethering to improve long-term durability of modern FMR repair. Nevertheless, the prognostic impact of the underlying cardiomyopathy on the outcome after FMR repair is unknown.

METHODS

We analysed 84 consecutive heart failure patients with severe FMR, LV ejection fraction <40%, LV end-diastolic diameter ≥55 mm and tenting height >10 mm, who underwent ring annuloplasty and simultaneous bilateral papillary muscles relocation between June 2016 and March 2019. One-year outcome of 54 patients with ischaemic cardiomyopathy ('ICM group') was prospectively compared to the remaining 30 patients with dilated cardiomyopathy ('DCM group').

RESULTS

One-year survival was similar in both groups (96% in the 'ICM group' vs 97% in the 'DCM group'; P = 0.93). Furthermore, primary composite outcome (i.e. freedom from death or mitral regurgitation ≥ 2) at 1-year postoperatively was comparable between the study groups (94%in the 'ICM group' vs 87% in the 'DCM group'; P = 0.10). LV end-diastolic diameter 1-year after surgery was significantly reduced, as compared to preoperative values, in the 'DCM group' (P = 0.018), but not in the 'ICM group' (P = 0.058). Improvement of New York Heart Association functional class and reduction of serum levels of N-terminal pro-B natriuretic peptide at 1 year was comparable in both study groups.

CONCLUSIONS

Standardized relocation of both papillary muscles to correct FMR resulted in very satisfactory in-hospital and 1-year outcomes, in both ICM and DCM. DCM patients showed similar improvement in heart failure symptoms and LV re-remodelling compared to ICM patients. Subannular repair is developing towards a valid therapeutic option in heart failure patients presenting with severe FMR.

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.

Prognostic value of mitral valve tenting area in patients with functional mitral regurgitation

OBJECTIVES

Mitral valve (MV) repair in functional mitral regurgitation is still associated with suboptimal outcomes. Our goal was to determine whether the clinical outcome following MV repair correlates with preoperative tenting parameters.

METHODS

We retrospectively identified consecutive patients with functional mitral regurgitation who underwent an isolated MV annuloplasty during a 7-year period (2010-2016) from our institutional database. Preoperative tenting parameters (i.e. tenting height, coaptation length, tenting area, posterior mitral leaflet and anterior mitral leaflet angles and interpapillary muscle distance) were systematically measured. The primary end point was the composite of survival and freedom from adverse cardiac events. The follow-up protocol consisted of a structured clinical questionnaire and an analysis of the echocardiographic data.

RESULTS

A total of 240 patients (mean age 67.8 ± 9.8 years, 57% of men) were analysed. The overall 5-year survival rate for the whole study cohort was 74.7 ± 4.2%, and freedom from adverse cardiac events was 84.8 ± 3.4%. A tenting area ≥2.4 cm2 was identified as a cut-off value, independently predicting the composite primary study end point (hazard ratio 2.0; P = 0.03). Furthermore, a Kaplan-Meier analysis revealed a strong tendency towards worse 5-year outcomes in patients with a tenting area ≥2.4 cm2 (n = 153) versus patients with a tenting area <2.4 cm2 (n = 87) (65.3 ± 5.5% vs 77.1 ± 6.3%; P = 0.06).

CONCLUSIONS

MV annuloplasty is associated with acceptable clinical and echocardiographic outcomes in patients with functional mitral regurgitation 5 years postoperatively. A preoperative tenting area ≥2.4 cm2 showed a strong trend towards a worse 5-year survival rate and an increased risk of adverse cardiac events after an isolated MV annuloplasty.

Left ventricular reverse remodeling after successful subannular mitral valve repair in end-stage heart failure: a case report

Background

Due to ongoing left ventricular (LV) remodeling and consecutive geometric displacement of both papillary muscles, end-stage heart failure is frequently associated with relevant functional mitral regurgitation (FMR) Type IIIb. Treatment strategies of FMR and their prognostic impact are still controversial.

Case summary

We present a case of an 80-year-old patient who suffered from recurrent symptoms of congestive heart failure due to dilated cardiomyopathy and concomitant severe FMR. To specifically address severe tethering of both mitral leaflets heart team decision was to perform minimally invasive mitral valve repair (MVR) including a subannular LV remodeling procedure, instead of an interventional edge-to-edge repair (MitraClip^® procedure). In addition to mitral valve ring annuloplasty, standardized relocation of both papillary muscles was performed successfully, leading to a complete resolution of mitral leaflet tethering. There were no procedural complications and the patient was discharged with an excellent functional result without residual mitral regurgitation. Furthermore, after 12 and 24 months, he reported an increase of his functional exercise capacity and a remarkable reverse LV remodeling could be demonstrated.

Discussion

Novel subannular repair techniques, especially the relocation of both papillary muscles, specifically address severe leaflet tethering in FMR and have an obvious potential to improve long-term competence of MVR. Therefore, they could be considered as a viable therapeutic option even in elderly patients presenting with end-stage cardiomyopathy and severe leaflet tenting.

Papillary muscle intervention vs mitral ring annuloplasty in ischemic mitral regurgitation

Background and Aims

The main pathophysiological factor of chronic ischemic mitral regurgitation (MR) is the outward displacement of the papillary muscles (PMs) leading to leaflet tethering. For this reason, papillary muscle intervention (PMI) in combination with mitral ring annuloplasty (MRA) has recently been introduced into clinical practice to correct this displacement, and to reduce the recurrence of regurgitation.

Methods

A meta‐analysis was conducted comparing the outcomes of PMI and MRA performed in combination vs MRA performed alone, in terms of MR recurrence and left ventricular reverse remodeling (LVRR). A meta‐regression was carried out to investigate the impact of the type of PMI procedure on the outcomes.

Results

MR recurrence in patients undergoing both PMI and MRA was lower than in those who only had MRA (log incidence rate ratio, −0.66; lower‐upper limits, −1.13 to 0.20; I² = 0.0%; p = .44; Egger's test: intercept 0.35 [−0.78 to 1.51]; p = .42).

The group with both PMI and MRA and that with only MRA showed a slightly higher reduction in left ventricular diameters (−5.94%; −8.75% to 3.13%,). However, in both groups, LVRR was <10%. No difference was detected between PM relocation/repositioning and papillary muscle approximation in terms of LVRR (p = .33).

Conclusions

Using PMI and MRA together has a lower MR recurrence than using MRA alone. No significant LVRR was observed between the two groups nor between the PMI techniques employed.