Current Indications for Transcatheter Mitral Valve Replacement Using Transcatheter Aortic Valves: Valve-in-Valve, Valve-in-Ring, and Valve-in-Mitral Annulus Calcification.

Use of transcatheter mitral valve replacement (TMVR) using transcatheter aortic valves in clinical practice is limited to patients with failing bioprostheses and rings or mitral valve disease associated with severe mitral annulus calcification. Whereas the use of valve-in-valve TMVR appears to be a reasonable alternative to surgery in patients at high surgical risk, much less evidence supports valve-in-ring and valve-in-mitral annulus calcification interventions. Data on the results of TMVR in these settings are derived from small case series or voluntary registries. This review summarizes the current evidence on TMVR using transcatheter aortic valves in clinical practice from the characteristics of the TMVR candidates, screening process, performance of the procedure, and description of current results and future perspectives. TMVR using dedicated devices in native noncalcified mitral valve diseases is beyond the scope of the article.

Trends in MitraClip, mitral valve repair, and mitral valve replacement from 2000 to 2016.

OBJECTIVE: The dissemination of mitral valve repair as the first-line treatment and the introduction of MitraClip for patients who have a prohibitive risk for surgery have changed the landscape of mitral valve intervention. The aim of this study is to provide current and generalizable data regarding the trend of mitral valve interventions and outcomes from 2000 to 2016. METHODS: Patients ≥18 years of age who underwent mitral-valve interventions were identified using the National Inpatient Sample database. National estimates were generated by means of discharge weights; comorbid conditions were identified using Elixhauser methods. All trends were analyzed with JoinPoint software. RESULTS: A total of 656,030 mitral valve interventions (298,102 mitral valve replacement, 349,053 mitral valve repair, and 8875 MitraClip) were assessed. No changes in rate of procedures (per 100,000 people in the United States) were observed over this period (annual percent change, -0.4; 95% confidence limit, -1.1 to 0.3; P = .3). From 2000 to 2010, the number of replacements decreased by 5.6% per year (P < .001), whereas repair increased by 8.4% per year from 2000 to 2006 (P < .001). MitraClip procedures increased by 84.4% annually from 2013 to 2016 (P < .001). The burden of comorbidities increased throughout the study for all groups, with the greatest score for MitraClip recipients. Overall, length of stay has decreased for all interventions, most significantly for MitraClip. In-hospital mortality decreased from 8.5% to 3.7% for all interventions, with MitraClip having the most substantial decrease from 3.6% to 1.5%. CONCLUSIONS: Over a 17-year period, mitral-valve interventions were associated with improved outcomes despite being applied to an increasingly sicker population.

Contemporary trends in mitral valve surgery in East China: a 10-year experience.

BACKGROUND: Contemporary nationwide data from mainland China on trends in mitral valve surgery are scarce. The purpose of the present study was to review a single-center experience with mitral valve surgery over a 10-year period in East China. METHODS: Between July 2009 and June 2019, 3238 consecutive patients who underwent mitral valve surgery in our center were retrospectively reviewed. The patients were evenly divided into three periods: July 2009 to October 2012 (period I), November 2012 to February 2016 (period II), March 2016 to June 2019 (period III). RESULTS: The 3238 patients included 536 (16.6%) who had mitral valve repair and 2702 (83.4%) who had mitral valve replacement. Early mortalities for mitral valve repair and mitral valve replacement were 0.2% and 0.9%, respectively. There were trends towards a higher proportion of degenerative valve lesions (24.6%, 35.8%, 54.7% in periods I, II, and III, respectively) and a lower proportion of rheumatic valve lesions (71.0%, 62.6%, 38.0%) in more recent years. The proportions of minimally invasive surgery (0.7%, 2.1%, 30.2%), mitral valve repair (8.3%, 15.4%, 27.5%), use of a bioprosthesis (10.1%, 17.0%, 23.1%), and concomitant tricuspid valve procedures (13.2%, 28.5%, 46.0%) increased dramatically, while early mortality remained constant during the 10-year period (1.0%, 0.3%, 0.9%). CONCLUSIONS: In the past 10 years, the spectrum of mitral valve disease experienced a trend towards more degenerative valve lesions and less rheumatic valve lesions in East China. Mitral valve repair, bioprostheses, tricuspid valve repair, and minimally invasive surgery have been more often applied in recent years.

Mitral Valve Surgical Volume and Transcatheter Mitral Valve Repair Outcomes: Impact of a Proposed Volume Requirement on Geographic Access.

Background There is an open Centers for Medicare and Medicaid Services National Coverage Decision for Transcatheter Mitral Valve Repair (TMVr) and a recent multisociety consensus document suggesting that TMVr centers should achieve prespecified mitral valve replacement or repair (MVRr). Yet, little is known about the MVRr volume-TMVr outcome relationship. Methods and Results Using Centers for Medicare and Medicaid Services administrative claims from January 1, 2016 to December 31, 2018, we computed the Pearson correlation coefficient and performed multivariable hierarchical modeling to estimate the MVRr volume to TMVr outcome relationship for mortality and heart failure hospitalization. Additionally, we assessed the impact of the consensus recommendations on geographic access to care by hospital referral region. Total annualized MVRr volume was <11 to 1552 (median 96, interquartile range 53, 167). One-year survival, 1-year heart failure hospitalization after TMVr were not correlated with MVRr volume. After patient risk-adjustment for age, sex, and significant Elixhauser Comorbidities, there remained no significant correlation between institutional MVRr volume and 1-year mortality (estimate -0.010, SE 0.047, P=0.834) or heart failure hospitalization (estimate -0.011, SE 0.045, P=0.808) after TMVr. Raising the restriction on TMVr from 20 to 40 MVRr/y results in ≈30 million individuals having to travel outside of their hospital referral region to undergo TMVr, with a disproportionate impact in the Midwest and Southeast. Conclusions There is no relationship between MVRr volumes and TMVr outcomes. Additionally, adoption of an annual MVRr volume ≥40 for performance of TMVr disproportionately impacts geographic access in the Midwest and Southeast and their large black and Hispanic populations.

Secondary mitral regurgitation: pathophysiology, proportionality and prognosis.

Secondary mitral regurgitation (SMR) occurs as a result of multifactorial left atrioventricular dysfunction and maleficent remodelling. It is the most common and undertreated form of mitral regurgitation (MR) and is associated with a very poor prognosis. Whether SMR is a bystander reflecting the severity of the cardiomyopathy disease process has long been the subject of debate. Studies suggest that SMR is an independent driver of prognosis in patients with an intermediate heart failure (HF) phenotype and not those with advanced HF. There is also no universal agreement regarding the quantitative thresholds defining severe SMR and indeed there are challenges with echocardiographic quantification. Until recently, no surgical or transcatheter intervention for SMR had demonstrated prognostic benefit, in contrast with HF medical therapy and cardiac resynchronisation therapy. In 2018, the first two randomised controlled trials (RCTs) of edge-to-edge transcatheter mitral valve repair versus guideline-directed medical therapy in HF (Percutaneous Repair with the MitraClip Device for Severe (MITRA-FR), Transcather mitral valve repair in patients with heart failure (COAPT)) reported contrasting yet complimentary results. Unlike in MITRA-FR, COAPT demonstrated significant prognostic benefit, largely attributed to the selection of patients with disproportionately severe MR relative to their HF phenotype. Consequently, quantifying the degree of SMR in relation to left ventricular volume may be a useful discriminator in predicting the success of transcatheter intervention. The challenge going forward is the identification and validation of such parameters while in parallel maintaining a heart-team guided holistic approach.

Temporal Trends on Percutaneous Mitral Commissurotomy: 30 Years of Experience.

Background Percutaneous mitral commissurotomy ( PMC ) was the first available transcatheter technique for treatment of mitral valve diseases. Experience has led to extending the indications to patients with less favorable characteristics. We aimed to analyze (1) the temporal trends in characteristic and outcomes of patients undergoing PMC in a single center over 30 years and (2) the predictive factors of poor immediate results of PMC . Methods and Results From 1987 to 2016, 1 full year for each decade was analyzed: 1987, 1996, 2006, and 2016. Poor immediate results of PMC were defined as a mitral valve area <1.5 cm2 or MR (mitral regurgitation) grade >2. Mitral anatomy was assessed using the Cormier classification and the fluoroscopic extent of calcification. Six hundred three patients were included: 111, 202, 205, and 85, respectively. Mean age increased >10 years over time ( P<0.0001). Mitral anatomy was less favorable over the years: the presence of calcification increased from 25% of patients at the beginning of PMC to >40% during the past decade ( P<0.0001) with a 3-fold increase in severe mitral calcification. Consistently, the proportion of good immediate results decreased over time ( P<0.05) but remained at 76% in 2016. Multivariate analysis showed 3 predictive factors of poor immediate results: smaller baseline mitral valve area ( P<0.0001), pre- PMC MR grade 2 ( P<0.01), and the presence or amount of calcification ( P<0.001). Conclusions This clinic's patients became significantly older with more frequent and severe calcification in the past decade. Predictive factors of poor immediate results were related to valve anatomy, including calcification. Despite challenges raised by severe calcification, PMC was still successful in >3 out of 4 patients in recent years.

Contemporary trends and outcomes of mitral valve surgery for infective endocarditis.

BACKGROUND: Contemporary data on mitral valve (MV) surgery in patients with infective endocarditis (IE) are limited. METHODS: The National Inpatient Sample was queried to identify patients with IE who underwent MV surgery between 2003 and 2016. We assessed (a) temporal trends in the incidence of MV surgery for IE, (b) morbidity, mortality, and cost of MV repair vs replacement, and (c) predictors of in-hospital mortality. RESULTS: The proportion of MV operations involving patients with IE increased from 5.4% in 2003 to 7.3%, and the proportion of MV repair among those undergoing surgery for IE increased from 15.2% to 25.0% (Ptrend < .001). In-hospital mortality was higher in the replacement group (11.3% vs 8.1%; P < .001), and this excess mortality persisted after propensity score matching (11.2% vs 8.1%; P < .001), and in sensitivity analyses excluding concomitant surgery (unadjusted 11.3% vs 4.8%; adjusted 8.5% vs 4.5%; P < .001), and stratifying patients by the time of operation (within 7 days, 11.3% vs 6.8%; P < .001 and >7 days, 11.9% vs 9.1%; P = .012). In the propensity-matched cohorts, shock and need for tracheostomy were more frequent in the replacement group, but rates of stroke, pacemaker implantation, new dialysis, and blood transfusion were similar. Mitral valve repair was, however, associated with shorter hospitalizations, more home discharges, and less cost. In a multivariate regression analysis, age above 70 and chronic dialysis were the strongest predictors of in-hospital mortality. CONCLUSION: Mitral valve repair in IE patients is associated with lower in-hospital mortality, resource utilization, and cost compared with MV replacement.

Mitral Valve Repair Rate at a Veterans Affairs Hospital Utilizing a Multidisciplinary Heart Team.

Between 2000 and 2008, the mitral valve (MV) repair rate in patients with severe mitral regurgitation at our low-volume Veterans Affairs hospital was 21%. After instituting a multidisciplinary valve team in 2009, we determined whether this rate increased and characterized the outcomes of patients with degenerative disease. We retrospectively reviewed data from 103 MV operations performed at our hospital between 1/2009 and 8/2016. MV pathology was categorized as degenerative, rheumatic, endocarditis, ischemic, hypertrophic cardiomyopathy, or failed prior MV repair. The surgical techniques used for MV repair were reviewed. For the patients with degenerative disease who underwent MV repair, we assessed leaflet involvement and postoperative valve function. For the full cohort, the MV repair rate was 67% and the 30-day mortality rate was 0.97%. Of the 74 patients with degenerative disease, 64 (86.5%) underwent MV repair (none required reoperation). For these patients, the MV repair rate was significantly higher when the surgical approach was sternotomy rather than minimally invasive right minithoracotomy (92.5% vs 71.4%, P = 0.03). After MV repair, 95.3% of the degenerative disease patients had mild or less mitral regurgitation; median echocardiography follow-up time was 555 days. Anatomic features associated with a reduced MV repair rate in patients with degenerative disease were dystrophic leaflet calcification and severe mitral annular calcification. In an institution with a low volume of MV operations, preoperative surgical planning with a multidisciplinary valve team was associated with improved MV repair rates and excellent repair quality in patients with degenerative valve disease.

Transcatheter Mitral Valve Intervention for Chronic Mitral Regurgitation: A Plethora of Different Technologies.

Chronic mitral regurgitation (MR) remains a common cardiovascular condition resulting in significant morbidity and mortality. With an aging population, increasing trends for both primary (degenerative) and secondary (functional) MR have become apparent. Although the gold standard remains surgical intervention with mitral valve repair/replacement, comorbid conditions have steered the development of less invasive technologies to mitigate perioperative surgical risk. Transcatheter mitral valve repair using a percutaneous edge-to-edge technique is the most widely available choice at present. However, other transcatheter mitral valve repair techniques such as annuloplasty and chordal implantation are notable alternatives. Moreover, emerging technologies in transcatheter mitral valve replacement are rapidly establishing their roles in the field of chronic severe MR therapy. Hence, it is imperative to understand the indications and limitations of these various transcatheter mitral valve interventions to provide the best and most up-to-date clinical care for patients. This review will outline current evidence and patient selection criteria for such device-based therapies.

Population trends in mitral valve surgery in Finland between 1997 and 2014: the finnish CVD register.

OBJECTIVES: Contemporary, nationwide data on trends in mitral valve surgery are scarce. Our aim was to investigate changes in procedure rates, patient selection, and post-procedural prognosis of open-heart mitral valve surgery in Finland. DESIGN: We combined data from three nationwide administrative registers with compulsory reporting. We identified patients who had undergone first-ever open-heart mitral valve surgery between 1997 and 2014 and followed them for adverse events. We examined trends in mitral valve surgery over three six-year time periods (1997-2002, 2003-2008, and 2009-2014). RESULTS: 3684 mitral valve procedures (mean age: 67.0 ± 10.9 years, 42.6% women) were performed in 1997-2014 in Finland. During this period, mitral valve repair operations became more common than replacements and we observed an increasing trend in the use of bioprosthetic valves. Between 1997-2002 and 2009-2014, the mean age of patients undergoing mitral valve surgery and the proportion of urgent surgeries increased (p < .001 for both). The proportion of women undergoing surgery decreased while the share of patients with hypertension (p = .023) or diabetes (p = .026) increased. The multivariable-adjusted risk of 28-day (hazard ratio, 0.55; 95% confidence interval, 0.37-0.83) and 6-year (hazard ratio, 0.80; 95% confidence interval, 0.67-0.97) post-operative mortality was lower in the last six-year period than in 1994-1998. CONCLUSIONS: Short- and long-term mortality of mitral valve surgery patients in Finland has decreased from 1997 to 2014 despite the patients being older and having more comorbidities. Understanding the changing characteristics and prognosis of these patients is important for the interpretation of previous and future cohort studies and trials.

Mitral valve surgery in the US Veterans Administration health system: 10-year outcomes and trends.

OBJECTIVE: To compare mitral valve repair (MVRepair) and mitral valve replacement (MVReplace) trends in the Veterans Affairs (VA) Surgical Quality Improvement Program. METHODS: Trends were compared by bivariate analyses, followed by backward stepwise selection and multivariable logistic modeling to determine the effect of preoperative comorbidities and facility-level factors on MVRepair (vs MVReplace) rate. A subgroup analysis focused on patients who underwent elective surgery for isolated primary degenerative mitral regurgitation. Propensity matching was done in the overall and primary degenerative cohorts. RESULTS: From October 2000 to October 2013, 4165 veterans underwent MVRepair (n = 2408) or MVReplace (n = 1757) for MV disease of any cause at 40 VA medical centers (procedural volume, 0-29/y; median 7/y). The MVRepair percentage increased from 48% in 2001 to 63% in 2013 (P < .001). MVRepair rates varied widely among centers; center volume explained only 19% of this variation after adjustment for case mix (R2 = 0.19, P = .005). Unadjusted 30-day and 1-year mortality rates were lower after MVRepair than after MVReplace (3.5% vs 4.8%, P = .04; 9.8% vs 12.1%, P = .02). Among the propensity-matched patients (n = 2520), 30-day and 1-year mortality were similar after MVRepair and MVReplace. In the propensity-matched primary degenerative subgroup (n = 664), unadjusted long-term mortality for up to 10 years postoperatively was lower after MVRepair (28% vs 37%, P = .003), as was risk-adjusted long-term mortality (hazard ratio, 0.78; 95% confidence interval, 0.61-1.01). CONCLUSIONS: In the VA Health System, mortality after MV operations is low. Despite the survival advantage associated with MV repair in primary mitral regurgitation, repair is infrequent at some centers, representing an opportunity for quality improvement.

Outcomes in Degenerative Mitral Regurgitation: Current State-of-the Art and Future Directions.

Mitral regurgitation (MR) is the one of the most frequent valvular heart diseases in the developed world, often requiring surgical correction. Degenerative MR is the most common type of non-ischemic, organic MR in the western world. Since no medical treatment has been shown to be effective in preventing the consequences of volume overload in asymptomatic degenerative MR, risk stratification is essential. Currently, this is achieved using clinical and precisely quantified echocardiographic parameters, with newer technologies like cardiac magnetic resonance gaining increasing prominence. While surgical mitral repair, often performed using minimally invasive/robotic techniques, is the current gold-standard for definitive therapeutic management, there is rapid emergence of percutaneous techniques for mitral valve repair/replacement in cases of degenerative MR. This state-of-the-art-review will discuss the latest knowledge in the natural history, imaging, surgical and percutaneous therapies in patients with degenerative MR.

Minimally invasive mitral valve annuloplasty confers a long-term survival benefit compared with state-of-the-art treatment in heart failure with functional mitral regurgitation.

BACKGROUND: Clinical impact of the minimally invasive surgical mitral valve annuloplasty (MVA) of functional mitral regurgitation (FMR) in systolic heart failure on top of the state-of-the-art standards of care remains controversial. Therefore, we aimed to compare clinical outcomes of isolated MVA using the mini-invasive videothoracoscopic approach versus the state-of-the-art (CON=conservative) treatment in patients with chronic systolic heart failure and symptomatic FMR. METHODS: The study population consisted of 379 patients (age 68.9±11.0years, 62.8% males) with left ventricular (LV) systolic dysfunction, symptomatic FMR and previous heart failure hospitalization. A total of 167 patients underwent undersized MVA and 212 patients were treated conservatively. A concomitant MAZE was performed in 53 (31.7%) patients. RESULTS: In the MVA group, the periprocedural and the 30-day mortality were 1.2% and 4.8%, respectively. During the median follow-up of 7.1years (IQR 3.5-9.8years) a total of 74 (44.3%) and 138 (65.1%) died in the MVA and the CON group, respectively (p<0.001). The lowest mortality was observed in MVA combined with MAZE (22.6%; p<0.01). In Cox regression analysis, age, MVA with MAZE emerged as independent predictors of both all-cause mortality and rehospitalizations for heart failure (all p<0.05). MVA was associated with significantly greater symptomatic improvement and reduction of FMR than the conservative treatment (both p<0.001). Reverse LV remodeling was observed only in the MVA combined with MAZE group (p<0.01). CONCLUSIONS: In patients with symptomatic FMR, minimally invasive MVA, in particular in combination with MAZE, confers an independent long-term survival benefit compared with the state-of-the-art treatment.

Current status of transcatheter mitral valve repair therapies - From surgical concepts towards future directions.

Transcatheter mitral valve (MV) intervention has emerged as an effective treatment option for symptomatic severe mitral regurgitation (MR) in patients considered to be inoperable or at high operative risk for surgical MV surgery. In primary mitral regurgitation, surgical repair is the standard of care. Transcatheter edge-to-edge MV repair with the MitraClip system has the largest clinical experience to date and offers a sustained clinical benefit in selected surgical high-risk patients. Surgery for secondary MR remains a challenge. Indications and the preferred surgical procedure remain controversial, mainly because of high recurrence rate of MR and the absence of evidence for survival benefit after surgery. Secondary MR is currently the most common indication for MitraClip use in Europe. Many registries show the safety of this procedure and improvements in patient symptoms and quality of life after 1 year, but most patients still have considerable residual MR. Other transcatheter MV repair devices are still in their early experiences. However, durability, safety, and possible damage of adjacent cardiac structures remain important concerns. Future directions for treatment of patients with secondary MR will depend on outcomes from the clinical trials in progress, whatever the use of transcatheter techniques is expected to expand substantially in the next years. This review aims to provide an overview of transcatheter MV interventions, emerging from surgical concepts, including leaflet repair, chordal replacement, and annuloplasty, and to discuss the challenges they face and future directions in achieving successful clinical application.

Transcatheter mitral valve regurgitation treatment: State of the art and a glimpse to the future.

Since the first transcatheter heart valve implantation in the pulmonary position in 2000 and in the aortic position in 2002, a large number of transcatheter heart valves have reached the clinical arena and thousands of high-risk patients have been treated successfully, in particular those with severe aortic stenosis. In contrast, the experience of transcatheter mitral valve repair or implantation started relatively more recently, and only a few devices are available at the moment. The aim of this review is to describe the different percutaneous systems for the treatment of mitral regurgitation.