Restrictive annuloplasty or replacement on reverse remodeling for nonischemic dilated cardiomyopathy.

BACKGROUND: For patients with nonischemic dilated cardiomyopathy (NIDCM), the indications for and results of mitral surgery remain controversial. We reviewed a strategy of mitral repair and replacement for clinically relevant secondary mitral regurgitation (MR) in patients with NIDCM. METHODS: We retrospectively reviewed 65 patients with advanced NIDCM (LVEF < 40%) who underwent mitral surgery. Of them, 47 (72%) underwent mitral annuloplasty and 18 (28%) replacement for secondary MR. The primary endpoint was postoperative reduction in indexed LV end-systolic volume (LVESVI). RESULTS: At baseline, there was no intergroup difference in LVESVI (123 ± 47 vs. 147 ± 37 ml/m2, P = 0.055), LVEF (27 ± 8% vs. 25 ± 6%, P = 0.41), incidence of severe MR (57% (27/47) vs. 72% (13/18), P = 0.40), or EuroSCORE II score (6.2% vs. 7.6%, P = 0.90). At 6 months, the annuloplasty group reduced LVESVI to a greater degree than the replacement group (P < 0.001), yielding significantly smaller postoperative LVESVI (96 ± 59 vs. 154 ± 61 ml/m2, P < 0.001) and better LVEF (P < 0.001). The rates of moderate/severe recurrent MR were 17% (8/47) and 0%, respectively. Multivariable analysis demonstrated that mitral annuloplasty (OR 6.10, 95% CI 1.14-32.8, P = 0.035) was significantly associated with postoperative LV reverse remodeling. Cumulative survival was not different between the groups (P = 0.26). CONCLUSIONS: In patients with NIDCM, mitral annuloplasty reduced LV volume to a greater degree than did mitral replacement. These findings may assist with surgical options for secondary MR associated with NIDCM.

Large Animal Translational Validation of 3 Mitral Valve Repair Operations for Mitral Regurgitation Using a Mitral Valve Prolapse Model: A Comprehensive In Vivo Biomechanical Engineering Analysis.

BACKGROUND: Various mitral repair techniques have been described. Though these repair techniques can be highly effective when performed correctly in suitable patients, limited quantitative biomechanical data are available. Validation and thorough biomechanical evaluation of these repair techniques from translational large animal in vivo studies in a standardized, translatable fashion are lacking. We sought to evaluate and validate biomechanical differences among different mitral repair techniques and further optimize repair operations using a large animal mitral valve prolapse model. METHODS: Male Dorset sheep (n=20) had P2 chordae severed to create the mitral valve prolapse model. Fiber Bragg grating force sensors were implanted to measure chordal forces. Ten sheep underwent 3 randomized, paired mitral valve repair operations: neochord repair, nonresectional leaflet remodeling, and triangular resection. The other 10 sheep underwent neochord repair with 2, 4, and 6 neochordae. Data were collected at baseline, mitral valve prolapse, and after each repair. RESULTS: All mitral repair techniques successfully eliminated regurgitation. Compared with mitral valve prolapse (0.54±0.18 N), repair using neochord (0.37±0.20 N; P=0.02) and remodeling techniques (0.30±0.15 N; P=0.001) reduced secondary chordae peak force. Neochord repair further decreased primary chordae peak force (0.21±0.14 N) to baseline levels (0.20±0.17 N; P=0.83), and was associated with lower primary chordae peak force compared with the remodeling (0.34±0.18 N; P=0.02) and triangular resectional techniques (0.36±0.27 N; P=0.03). Specifically, repair using 2 neochordae resulted in higher peak primary chordal forces (0.28±0.21 N) compared with those using 4 (0.22±0.16 N; P=0.02) or 6 neochordae (0.19±0.16 N; P=0.002). No difference in peak primary chordal forces was observed between 4 and 6 neochordae (P=0.05). Peak forces on the neochordae were the lowest using 6 neochordae (0.09±0.11 N) compared with those of 4 neochordae (0.15±0.14 N; P=0.01) and 2 neochordae (0.29±0.18 N; P=0.001). CONCLUSIONS: Significant biomechanical differences were observed underlying different mitral repair techniques in a translational large animal model. Neochord repair was associated with the lowest primary chordae peak force compared to the remodeling and triangular resectional techniques. Additionally, neochord repair using at least 4 neochordae was associated with lower chordal forces on the primary chordae and the neochordae. This study provided key insights about mitral valve repair optimization and may further improve repair durability.

Prognostic Value of Right Ventricular Afterload in Patients Undergoing Mitral Transcatheter Edge-to-Edge Repair.

BACKGROUND: Pulmonary hypertension (PH) and secondary mitral regurgitation (MR) are associated with adverse outcomes after mitral transcatheter edge-to-edge repair. We aim to study the prognostic value of invasively measured right ventricular afterload in patients undergoing mitral transcatheter edge-to-edge repair. METHODS AND RESULTS: We identified patients who underwent right heart catheterization ≤1 month before transcatheter edge-to-edge repair. The end points were all-cause mortality and a composite of mortality and heart failure hospitalization at 2 years. Using the receiver operating characteristic curve-derived threshold of 0.6 for pulmonary effective arterial elastance ([Ea], pulmonary artery systolic pressure/stroke volume), patients were stratified into 3 profiles based on PH severity (low elastance [HE]: Ea <0.6/mean pulmonary artery pressure (mPAP)) <35; High Elastance with No/Mild PH (HE-): Ea ≥0.6/mPAP <35; and HE with Moderate/Severe PH (HE+): Ea ≥0.6/mPAP ≥35) and MR pathogenesis (Primary MR [PMR])/low elastance, PMR/HE, and secondary MR). The association between this classification and clinical outcomes was examined using Cox regression. Among 114 patients included, 50.9% had PMR. Mean±SD age was 74.7±10.6 years. Patients with Ea ≥0.6 were more likely to have diabetes, atrial fibrillation, New York Heart Association III/IV status, and secondary MR (all P<0.05). Overall, 2-year cumulative survival was 71.1% and was lower in patients with secondary MR and mPAP ≥35. Compared with patients with low elastance, cumulative 2-year event-free survival was significantly lower in HE- and HE+ patients (85.5% versus 50.4% versus 41.0%, respectively, P=0.001). Also, cumulative 2-year event-free survival was significantly higher in patients with PMR/low elastance when compared with PMR/HE and patients with secondary mitral regurgitation (85.5% versus 55.5% versus 46.1%, respectively, P=0.005). CONCLUSIONS: Assessment of the preprocedural cardiopulmonary profile based on mPAP, MR pathogenesis, and Ea guides patient selection by identifying hemodynamic features that indicate likely benefit from mitral-transcatheter edge-to-edge repair in PH or lack thereof.

Clinical and echocardiographic results of the MEMO 4D semi-rigid annuloplasty ring.

BACKGROUND: Mitral regurgitation is a frequent valvular disease, with an increasing prevalence. We analyzed the short-term outcomes of mitral valve repair procedures conducted in our clinic using a new semirigid annuloplasty ring featuring a gradual saddle shape design. METHODS: We retrospectively analyzed mitral valve repair surgeries performed at our Institution between December 2019 and November 2021 with the MEMO 4D semirigid annuloplasty ring. RESULTS: In total, 53 patients were included in the study. Mean patient age was 63.6 ± 11.7 years. Most patients presented with degenerative mitral valve regurgitation (N = 44; 83%). The grade of mitral regurgitation was equal or more than 3 + in 98.1% of the patients (N = 52). The most used ring size was size 34 mm (N = 30, 56.6%). There was no intraoperative or hospital mortality. No cases of stroke, bleeding, endocarditis or other major complications occurred. At discharge, most patients were in NYHA class I. Postoperative echocardiographic results showed no (90.6%) or 1+ (5.7%) mitral valve regurgitation. Only 1 patient (1.9%) presented with mitral valve regurgitation grade 2+. Mean postoperative transvalvular gradient was low (mean = 3.3 ± 1.2 mmHg). No cases of LVOT obstruction or systolic anterior motion occurred. CONCLUSIONS: Our series showed excellent mitral valve competency and very satisfactory early clinical outcomes. The transesophageal echocardiographic follow-up, despite obtained in a limited number of patients, further confirmed the effectiveness of findings of this preliminary experience.

Contemporary 1-Year Outcomes of Mitral Valve-in-Ring With Balloon-Expandable Aortic Transcatheter Valves in the U.S.

BACKGROUND: Adequate valve performance after surgical mitral valve repair with an annuloplasty ring is not always sustained over time. The risk of repeat mitral valve surgery may be high in these patients. Transcatheter mitral valve-in-ring (MViR) is emerging as an alternative for high-risk patients. OBJECTIVES: The authors sought to assess contemporary outcomes of MViR using third-generation balloon-expandable aortic transcatheter heart valves. METHODS: Patients who underwent MViR and were enrolled in the STDS/ACC TVT (Society of Thoracic Surgeons/American College of Cardiology Transcatheter Valve Therapy) Registry between August 2015 and December 2022 were analyzed. RESULTS: A total of 820 patients underwent MViR at 236 sites, mean age was 72.2 ± 10.4 years, 50.9% were female, mean STS score was 8.2% ± 6.9%, and most (78%) were in NYHA functional class III to IV. Mean left ventricular ejection fraction was 47.8% ± 14.2%, mean mitral gradient was 8.9 ± 7.0 mm Hg, and 75.5% had ≥ moderate mitral regurgitation. Access was transseptal in 93.9% with 88% technical success. All-cause mortality at 30 days was 8.3%, and at 1 year, 22.4%, with a reintervention rate of 9.1%. At 1-year follow-up, 75.6% were NYHA functional class I to II, Kansas City Cardiomyopathy Questionnaire score increased by 25.9 ± 29.1 points, mean mitral valve gradient was 8.4 ± 3.4 mm Hg, and 91.7% had ≤ mild mitral regurgitation. CONCLUSIONS: MViR with third-generation balloon-expandable aortic transcatheter heart valves is associated with a significant reduction in mitral regurgitation and improvement in symptoms at 1 year, but with elevated valvular gradients and a high reintervention rate. MViR is a reasonable alternative for high-risk patients unable undergo surgery who have appropriate anatomy for the procedure. (STS/ACC TVT Registry Mitral Module [TMVR]; NCT02245763).

Mitral Valve Transcatheter Edge-to-Edge Repair: 1-Year Outcomes From the MiCLASP Study.

BACKGROUND: Mitral transcatheter edge-to-edge repair (M-TEER) is a guideline-recommended treatment option for patients with severe symptomatic mitral regurgitation (MR). Outcomes with the PASCAL system in a post-market setting have not been established. OBJECTIVES: The authors report 30-day and 1-year outcomes from the MiCLASP (Transcatheter Repair of Mitral Regurgitation with Edwards PASCAL Transcatheter Valve Repair System) European post-market clinical follow-up study. METHODS: Patients with symptomatic, clinically significant MR were prospectively enrolled. The primary safety endpoint was clinical events committee-adjudicated 30-day composite major adverse event rate and the primary effectiveness endpoint was echocardiographic core laboratory-assessed MR severity at discharge compared with baseline. Clinical, echocardiographic, functional, and quality-of-life outcomes were assessed at 1 year. RESULTS: A total of 544 patients were enrolled (59% functional MR, 30% degenerative MR). The 30-day composite major adverse event rate was 6.8%. MR reduction was significant from baseline to discharge and sustained at 1 year with 98% of patients achieving MR ≤2+ and 82.6% MR ≤1+ (all P < 0.001 vs baseline). One-year Kaplan-Meier estimate for survival was 87.3%, and freedom from heart failure hospitalization was 84.3%. Significant functional and quality-of-life improvements were observed at 1 year, including 71.6% in NYHA functional class I/II, 14.4-point increase in Kansas City Cardiomyopathy Questionnaire score, and 24.2-m improvement in 6-minute walk distance (all P < 0.001 vs baseline). CONCLUSIONS: One-year outcomes of this large cohort from the MiCLASP study demonstrate continued safety and effectiveness of M-TEER with the PASCAL system in a post-market setting. Results demonstrate high survival and freedom from heart failure hospitalization, significant and sustained MR reduction, and improvements in symptoms, functional capacity, and quality of life.

To repair or to replace in mitral valve infective endocarditis? an updated meta-analysis.

BACKGROUND: Valve infective endocarditis (IE) is a potentially life-threatening condition that affects patients' livelihoods. Current surgical options in mitral valve IE include mitral valve repair (MVr) or replacement (MVR). While each procedure boasts its merits, doubt remains as to which type of surgery is superior. METHODS: We searched PubMed, Scopus, Web of Science, and Cochrane literature databases for studies comparing MVR and MVr in mitral valve IE. Any randomized controlled trial (RCT) or observational studies that compare MVR vs. MVr in mitral valve IE were eligible. Our dichotomous outcomes were extracted in the form of event and total, and risk and hazard ratio (RR)(HR) with 95% confidence interval (CI) and were pooled and calculated using RevMan 5.0. RESULTS: Our study included 23 studies with a total population of 11,802 patients. Compared to MVR, MVr had statistically significant lower risks of both early mortality with RR [0.44; 95% CI, 0.38-0.51; p < 0.001] and long-term follow-up mortality with HR [0.70; 95% CI, 0.58-0.85; p = 0.0004]. Moreover, MVr was associated with a statistically significant lower risk of IE recurrence with RR [0.43; 95% CI, 0.32-0.58; p < 0.001]; however, no statistically significant differences between both groups in terms of re-operations with RR [0.83; 95% CI, 0.41-1.67; p = 0.60]. CONCLUSION: Our results suggest that MVr was superior in terms of in-hospital mortality, long-term survival, and risk of recurrence without significance in valve reoperation. Therefore, MVr is appropriate as a primary treatment choice and should be considered whenever possible in most IE patients.

Mid-term clinical outcomes of totally endoscopic repair for mitral regurgitation in Barlow's disease.

OBJECTIVE: This study aimed to confirm the safety and feasibility of totally endoscopic repair for mitral regurgitation (MR) in Barlow's disease. METHODS: From June 2018 to December 2022, 21 consecutive Barlow's disease patients (aged 33 ± 12 years; 57.1% male) underwent totally endoscopic mitral valve (MV) repair with leaflets folding, multiple artificial chordae implantation and ring annuloplasty. The safety and feasibility of this technique was evaluated by its mid-term clinical outcomes. RESULTS: There was no operative death or complications. The mean cardiopulmonary bypass (CPB) time was 190 ± 41 (128-267) min, and the aortic cross-clamp time was 145 ± 32 (66-200) min. The average number of artificial chordae implantation was 2.9 ± 0.7 (1-4) pairs. The mean MV coaptation length was 1.4 ± 0.3 (0.8-1.8) cm, and the median transvalvular gradient was 1 [interquartile range (IQR), 1-2] mmHg. During a median follow-up time of 24 (IQR, 10-38) months, all patients showed persistent effective valve function with no significant MR or systolic anterior motion. CONCLUSIONS: Totally endoscopic repair was a safe, effective, and reproducible procedure with satisfied mid-term clinical outcomes for MR in Barlow's disease. However, further randomized and long-term follow-up studies were warranted to determine its clinical effects.

Interpapillary muscle distance independently predicts recurrent mitral regurgitation.

OBJECTIVE: Ischaemic secondary mitral regurgitation (ISMR) after surgery is due to the displacement of papillary muscles resulting from progressive enlargement of the left ventricle end-diastolic diameter (LVEDD). Our aim was to prove that if the interpapillary muscle distance (IPMD) is surgically stabilized, an increase in LVEDD will not lead to a recurrence of ischaemic mitral regurgitation (MR). METHODS: Ninety-six patients with ISMR, who underwent surgical revascularisation and annuloplasty, were randomly assigned in a 1:1 ratio to undergo papillary muscle approximation (PMA). At the 5-year follow-up, we assessed the correlation between PMA and echocardiographic improvements, the effect size of PMA on echocardiographic improvements, and a prediction model for recurrent MR using inferential tree analysis. RESULTS: There was a significant correlation between PMA and enhancements in both the α and ß angles (Spearman's rho > 0.7, p < 0.01). The α angle represents the angle between the annular plane and either the A2 annular-coaptation line or the P2 annular-coaptation line. The ß angle indicates the angle between the annular plane and either the A2 annular-leaflet tip line or the P2 annular-leaflet tip line. PMA led to substantial improvements in LVEDD, tenting area, α and ß angles, with a large effect size (Hedge's g ≥ 8, 95% CI ORs ≠ 1). The most reliable predictor of recurrent MR grade was the interpapillary distance, as only patients with an interpapillary distance greater than 40 mm developed ≥ 3 + grade MR. For patients with an IPMD of 40 mm or less, the best predictor of recurrent MR grade was LVEDD. Among the patients, only those with LVEDD greater than 62 mm showed moderate (2+) MR, while only those with LVEDD less than or equal to 62 mm had absent to mild (1+) MR. CONCLUSION: Prediction of recurrent ischaemic MR is not independent of progressive LVEDD increase. PMA-based surgical procedure stabilises IPMD.

[Supra-annular Mitral Valve Replacement Using a Composite Valve for an Infant with Acute Rupture of Chordae Tendineae].

Acute rupture of the chordae tendineae of the mitral valve could lead to severe mitral regurgitation and circulatory collapse in infants. Mitral valve replacement may be often challenging because of the valve-annulus size mismatch in small infants when mitral valve repair cannot be accomplished. We present an infant with acute massive rupture of the chordae tendineae of the mitral valve who successfully underwent supra-annular mitral valve replacement using the short composite valve of an expanded polytetrafluoroethylene( ePTFE) graft and a mechanical valve. His mechanical valve has been functioning without complications such as thrombosis and pulmonary venous obstruction for 20 months after surgery. This technique could be helpful even infants with acute rupture of the chordae tendineae of the mitral valve whose left atrium may not be dilated.

Patient Risk-Benefit Preferences for Transcatheter Versus Surgical Mitral Valve Repair.

BACKGROUND: Transcatheter edge-to-edge repair (TEER) of mitral regurgitation is less invasive than surgery but has greater 5-year mortality and reintervention risks, and leads to smaller improvements in physical functioning. The study objective was to quantify patient preferences for risk-benefit trade-offs associated with TEER and surgery. METHODS AND RESULTS: A discrete choice experiment survey was administered to patients with mitral regurgitation. Attributes included procedure type; 30-day mortality risk; 5-year mortality risk and physical functioning for 5 years; number of hospitalizations in the next 5 years; and risk of additional surgery in the next 5 years. A mixed-logit regression model was fit to estimate preference weights. Two hundred one individuals completed the survey: 63% were female and mean age was 74 years. On average, respondents preferred TEER over surgery. To undergo a less invasive procedure (ie, TEER), respondents would accept up to a 13.3% (95% CI, 8.7%-18.5%) increase in reintervention risk above a baseline of 10%, 4.6 (95% CI, 3.1-6.2) more hospitalizations above a baseline of 1, a 10.7% (95% CI, 6.5%-14.5%) increase in 5-year mortality risk above a baseline of 20%, or more limited physical functioning representing nearly 1 New York Heart Association class (0.7 [95% CI, 0.4-1.1]) over 5 years. CONCLUSIONS: Patients in general preferred TEER over surgery. When holding constant all other factors, a functional improvement from New York Heart Association class III to class I maintained over 5 years would be needed, on average, for patients to prefer surgery over TEER.

Comparison of Transcatheter Edge-to-Edge Mitral Valve Repair for Primary Mitral Regurgitation Outcomes to Hospital Volumes of Surgical Mitral Valve Repair.

BACKGROUND: Transcatheter edge-to-edge mitral valve (MV) repair (TEER) is an effective treatment for patients with primary mitral regurgitation at prohibitive risk for surgical MV repair (MVr). High-volume MVr centers and high-volume TEER centers have better outcomes than low-volume centers, respectively. However, whether MVr volume predicts TEER outcomes remains unknown. We hypothesized that high-volume MV surgical centers would have superior risk-adjusted outcomes for TEER than low-volume centers. METHODS: We combined data from the American College of Cardiology/Society of Thoracic Surgeons Transcatheter Valve Therapy registry and the Society of Thoracic Surgeons adult cardiac surgery database. MVr was defined as leaflet resection or artificial chords with or without annuloplasty and was evaluated as a continuous variable and as predefined categories (<25, 25-49, and ≥50 MV repairs/year). A generalized linear mixed model was used to evaluate risk-adjusted in-hospital/30-day mortality, 30-day heart failure readmission, and TEER success (mitral regurgitation ≤2+ and gradient <5 mm Hg). RESULTS: The study comprised 41 834 patients from 500 sites of which 332 (66.4%) were low, 102 (20.4%) intermediate, and 66 (13.2%) high-volume surgical centers (P<0.001). TEER success was 54.6% and was not statistically significantly different across MV surgical site volumes (P=0.4271). TEER mortality at 30 days was 3.5% with no significant difference across MVr volume on unadjusted (P=0.141) or adjusted (P=0.071) analysis of volume as a continuous variable. One-year mortality was 15.0% and was lower for higher MVr volume centers when adjusted for clinical and demographic variables (P=0.027). Heart failure readmission at 1 year was 9.4% and was statistically significantly lower in high-volume centers on both unadjusted (P=0.017) or adjusted (P=0.015) analysis. CONCLUSIONS: TEER can be safely performed in centers with low volumes of MV repair. However, 1-year mortality and heart failure readmission are superior at centers with higher MVr volume.

The study of loading mode with in-vitro fatigue testing for mitral annuloplasty ring.

To maintain the physiological dynamics of the mitral annulus, mitral annuloplasty rings (MAR) must be flexible. Enhanced flexibility implies decreased resistance to fatigue and potential for fatigue fracture. This study established new methods to test the flexible fatigue life of MAR in-vitro using numerical analysis; the purpose is that the fatigue test could reflect the real stress distribution in-vivo. Based on the conventional test methods (C1, D1), this paper presents a novel test method (C2, D2). Four testing methods for open-end annuloplasty rings (C1, C2) and closed-end annuloplasty rings (D1, D2) were modelled and their stress distribution calculated by finite element analysis. The mean absolute error (Χ) and the Pearson correlation coefficient (Φ) were used to quantify the difference in stress distribution between the loading modes in-vivo and in-vitro. For closed-end annuloplasty rings, the novel test method (D2) is not obvious better than conventional test methods(D1) in duplicating the stress distribution (ΦD1 = 0.88 vs ΦD2 = 0.92). However, the maximum values of stress in the novel test method are closer to the maximum value of stress under in-vivo loading (ΧD1 = 5.2Mpa vs ΧD2 = 4.4Mpa). For open-end annuloplasty rings, the novel test method(C2) is obviously superior to the conventional test method(C1) in duplicating both the stress distribution and the stress peak values of the in-vivo loading (ΦC1 = 0.22 vs ΦC2 = 0.98; ΧC1 = 59.1Mpa vs ΧC2 = 11.0Mpa). The in-vitro loading methods described in this article more closely approximated in-vivo conditions compared to traditional methods. They are simpler to operate, more efficient and can help manufacturers expedite new product development, assist regulatory agencies with product quality oversight.