Computed Simulation of Transcatheter Edge-to-Edge Mitral Valve Repair - A Proof of Concept Study.

AIMS: As transcatheter mitral valve (MV) interventions are expanding and more device types and sizes become available, a tool supporting operators in preprocedural planning and the clinical decision-making process is highly desirable. We sought to develop a finite element (FE) computational simulation model to predict results of transcatheter edge-to-edge (TEER) interventions. METHODS AND RESULTS: We prospectively enrolled patients with secondary mitral regurgitation (MR) referred for a clinically indicated TEER. Three-dimensional (3D) transesophageal echocardiograms performed at the beginning of the procedure were used to perform the simulation. On the 3D dynamic model of the MV that was first obtained, we simulated the clip implantation using the same clip(s) type, size, number, and implantation location that was used during the intervention. The 3D model of the MV obtained after simulation of the clip implantation was compared to the clinical results obtained at the end of the intervention. We analyzed the degree and location of residual MR and the shape and area of the diastolic mitral valve area. We performed computational simulation on 5 patients. Overall, the simulated models predicted well the degree and location of the residual regurgitant orifice(s) but tended to underestimate the diastolic mitral orifice area. CONCLUSIONS: In this proof-of-concept study, we present preliminary results on our algorithm simulating clip implantation in 5 patients with functional MR. We show promising results regarding the feasibility and accuracy in terms of predicting residual MR and the need to improve the estimation of the diastolic mitral valve area.

Edge-to-edge with partial band mitral valve repair compared to replacement and undersized restrictive annuloplasty for ischemic mitral regurgitation.

Objective: Evidence supports replacement over repair for ischemic mitral regurgitation due to improved durability; however, the latter often involves an undersized ring annuloplasty that does not include edge-to-edge approximation. The objective of this study was to evaluate the outcomes of replacement, edge-to-edge leaflet approximation with mild-undersized annuloplasty and undersized ring annuloplasty for ischemic mitral regurgitation. Methods: This is a single-center retrospective study of patients undergoing mitral surgery for moderate-severe or greater ischemic mitral regurgitation, between 2004 and 2020, with mild-undersized annuloplasty, mitral valve replacement, or undersized restrictive annuloplasty (undersized ring annuloplasty). The primary outcome was all-cause mortality. Secondary outcomes included first recurrence of mitral regurgitation, heart failure hospitalization, and composite of valve-related events (bleeding, thromboembolism, endocarditis, and mitral valve reoperation). Results: There were 121, 93, and 78 patients in the mitral valve replacement, mild-undersized annuloplasty, and undersized restrictive annuloplasty groups, respectively, with a median follow-up of 3.1, 5.9, and 3.8 years, respectively. Both mitral valve replacement (hazard ratio, 1.87; 95% CI, 1.029-3.415) and undersized restrictive annuloplasty (hazard ratio, 2.73; 95% CI, 1.480-5.061) were associated with worse survival compared with mild-undersized annuloplasty. At 2 years, the rate of mild-moderate mitral regurgitation was greater in the mild-undersized annuloplasty group compared with the mitral valve replacement group (P = .001) but less than in the undersized restrictive annuloplasty group (P = .001). The rate of recurrent moderate or greater mitral regurgitation at 2 years was similar between mild-undersized annuloplasty and mitral valve replacement groups but significantly higher after undersized restrictive annuloplasty (P < .0001). Mitral valve replacement and undersized restrictive annuloplasty were associated with a significant increase in the incidence of first heart failure hospitalization compared with mild-undersized annuloplasty (P < .001 and P = .001, respectively). Mitral valve replacement was associated with an increased incidence of valve-related events compared with mild-undersized annuloplasty (P = .002). Conclusions: Surgical edge-to-edge approximation in addition to a mild-undersizing annuloplasty offers similar durability compared with replacement, with a lower rate of hospitalization for heart failure, and may confer a survival advantage.

Longitudinal Outcomes Following Surgical Repair of Primary Mitral Regurgitation.

Degenerative mitral valve (MV) disease is the most common cause of organic mitral regurgitation (MR) in developed countries. Surgical mitral valve repair is the gold standard treatment for primary MR. Surgical mitral valve repair is associated with excellent outcomes in terms of survival and freedom from recurrent MR. As well, innovations in surgical repair techniques, including thoracoscopically and robotically assisted approaches, further reduce morbidity. Emerging catheter-based therapies may also provide advantages in select patient groups. Although the outcomes following surgical mitral valve repair are well described in the literature, longitudinal follow-up is heterogenous. Indeed, longitudinal follow-up and long-term data are vital to better advise treatment and counsel patients.

Unmet needs in valvular heart disease.

Valvular heart disease (VHD) is the next epidemic in the cardiovascular field, affecting millions of people worldwide and having a major impact on health care systems. With aging of the population, the incidence and prevalence of VHD will continue to increase. However, VHD has not received the attention it deserves from both the public and policymakers. Despite important advances in the pathophysiology, natural history, management, and treatment of VHD including the development of transcatheter therapies, VHD remains underdiagnosed, identified late, and often undertreated with inequality in access to care and treatment options, and there is no medication that can prevent disease progression. The present review article discusses these gaps in the management of VHD and potential actions to undertake to improve the outcome of patients with VHD.

Prediction of acute kidney injury risk after cardiac surgery: using a hybrid machine learning algorithm.

BACKGROUND: Acute kidney injury (AKI) is a serious complication after cardiac surgery. We derived and internally validated a Machine Learning preoperative model to predict cardiac surgery-associated AKI of any severity and compared its performance with parametric statistical models. METHODS: We conducted a retrospective study of adult patients who underwent major cardiac surgery requiring cardiopulmonary bypass between November 1st, 2009 and March 31st, 2015. AKI was defined according to the KDIGO criteria as stage 1 or greater, within 7 days of surgery. We randomly split the cohort into derivation and validation datasets. We developed three AKI risk models: (1) a hybrid machine learning (ML) algorithm, using Random Forests for variable selection, followed by high performance logistic regression; (2) a traditional logistic regression model and (3) an enhanced logistic regression model with 500 bootstraps, with backward variable selection. For each model, we assigned risk scores to each of the retained covariate and assessed model discrimination (C statistic) and calibration (Hosmer-Lemeshow goodness-of-fit test) in the validation datasets. RESULTS: Of 6522 included patients, 1760 (27.0%) developed AKI. The best performance was achieved by the hybrid ML algorithm to predict AKI of any severity. The ML and enhanced statistical models remained robust after internal validation (C statistic = 0.75; Hosmer-Lemeshow p = 0.804, and AUC = 0.74, Hosmer-Lemeshow p = 0.347, respectively). CONCLUSIONS: We demonstrated that a hybrid ML model provides higher accuracy without sacrificing parsimony, computational efficiency, or interpretability, when compared with parametric statistical models. This score-based model can easily be used at the bedside to identify high-risk patients who may benefit from intensive perioperative monitoring and personalized management strategies.

Natural History of Mitral Annular Calcification and Calcific Mitral Valve Disease.

BACKGROUND: The natural history of mitral annular calcification (MAC) and risk for developing calcific mitral valve disease (CMVD) have been poorly defined. The aim of this study was to evaluate the progression rate of MAC and of the development of CMVD. METHODS: Patients with MAC and paired echocardiograms ≥1 year apart between 2005 and 2019 were included. Progression rates from mild or moderate to severe MAC and to CMVD (defined as severe MAC and significant mitral stenosis and/or regurgitation) were assessed, along with potential association with sex. RESULTS: A total of 11,605 patients (mean age, 73 ± 10 years; 51% men) with MAC (78% mild, 17% moderate, 5% severe) were included and underwent follow-up echocardiography at 4.2 ± 2.7 years. Among patients with mild or moderate MAC, 33% presented with severe MAC at 10 years. The rate of severe MAC was higher in women than in men (41% vs 24% [P < .001]; hazard ratio, 1.3; P < .001) and in patients with moderate versus mild MAC (71% vs 22% [P < .001]; hazard ratio, 6.1; P < .001). At 10 years, 10% presented with CMVD (4%, 23%, and 60% in patients with mild, moderate, and severe MAC, respectively), which was predicted by female sex (15% vs 5%; P < .0001), even after adjustment for MAC severity (hazard ratio, 1.9; P < .001). CONCLUSION: In this large cohort of patients with MAC, progression to severe MAC was common and frequently resulted in CMVD. Female sex was associated with higher progression rates. MAC and CMVD are expected to dramatically increase as the population ages, highlighting the importance of a better understanding of the pathophysiology of MAC to develop effective preventive medical therapies.

Derivation and validation of a clinical risk score to predict death among patients awaiting cardiac surgery in Ontario, Canada: a population-based study.

BACKGROUND: Surgical delay may result in unintended harm to patients needing cardiac surgery, who are at risk for death if their condition is left untreated. Our objective was to derive and internally validate a clinical risk score to predict death among patients awaiting major cardiac surgery. METHODS: We used the CorHealth Ontario Registry and linked ICES health administrative databases with information on all Ontario residents to identify patients aged 18 years or more who were referred for isolated coronary artery bypass grafting (CABG), valvular procedures, combined CABG-valvular procedures or thoracic aorta procedures between Oct. 1, 2008, and Sept. 30, 2019. We used a hybrid modelling approach with the random forest method for initial variable selection, followed by backward stepwise logistic regression modelling for clinical interpretability and parsimony. We internally validated the logistic regression model, termed the CardiOttawa Waitlist Mortality Score, using 200 bootstraps. RESULTS: Of the 112 266 patients referred for cardiac surgery, 269 (0.2%) died while awaiting surgery (118/72 366 [0.2%] isolated CABG, 81/24 461 [0.3%] valvular procedures, 63/12 046 [0.5%] combined CABG-valvular procedures and 7/3393 [0.2%] thoracic aorta procedures). Age, sex, surgery type, left main stenosis, Canadian Cardiovascular Society classification, left ventricular ejection fraction, heart failure, atrial fibrillation, dialysis, psychosis and operative priority were predictors of waitlist mortality. The model discriminated (C-statistic 0.76 [optimism-corrected 0.73]). It calibrated well in the overall cohort (Hosmer-Lemeshow p = 0.2) and across surgery types. INTERPRETATION: The CardiOttawa Waitlist Mortality Score is a simple clinical risk model that predicts the likelihood of death while awaiting cardiac surgery. It has the potential to provide data-driven decision support for managing access to cardiac care and preserve system capacity during the COVID-19 pandemic, the recovery period and beyond.

Systematic Approach to the Calcified Mitral Valve Apparatus at Time of Mitral Valve Replacement.

Mitral annular calcification (MAC) represents a surgical challenge to mitral valve replacement. The presence of MAC at the time of mitral valve replacement is associated with perivalvular leak and atrial-ventricular groove injury. Although percutaneous and hybrid approaches may offer alternatives to surgical mitral valve replacement, the early and late results from these techniques remain unknown. As such, the surgical management of MAC remains relevant in the contemporary treatment of patients with MAC. Herein, we present a systematic approach to the management of MAC at the time of mitral valve replacement.

Aortic Valve Repair Decreases Risks of VRE in AI at 10 Years: A Propensity Score-Matched Analysis.

BACKGROUND: Aortic valve repair (AVr) has emerged as a feasible and effective alternative to AV replacement (AVR) in patients with aortic insufficiency (AI); however, little data exist comparing outcomes. Thus, the objective of this study was to compare early and long-term valve-related complications between AVr and AVR in the treatment of AI. METHODS: This was a single-center, retrospective study of all patients (n = 417) undergoing AVr (n = 264) or AVR (n = 153) for primary AI. Propensity matching using a 1:1 greedy matching algorithm identified 140 patients using 6 covariates (age, sex, left ventricular function, size, presence of aortopathy, and urgency of operation) for comparison. The primary outcome was a composite of all valve-related events (VREs), including endocarditis, myocardial infarction stroke, transient ischemic attack, thromboembolisms, bleeding, and AV reoperation. VREs were defined as per published guidelines. Survival and freedom from VREs were reported using the Kaplan-Meier method. RESULTS: Propensity matching identified 70 well-matched pairs with no major differences in baseline demographics, comorbidities, or AI severity (P = .57). Perioperative outcomes showed no significant differences in VREs (AVR 8 vs AVr 7; P = .78) or mortality (AVR 3 vs AVr 1; P = .62). Event-free survival from the primary outcome at 10 years was significantly better after AVr than after AVR (82% vs 68%; P = .024), with no significant differences in 10-year overall survival between groups (82% vs 72%; P = .29). No significant differences in AI severity (P = .07) or reoperation rate (P = .44) were detected between groups. CONCLUSIONS: This study demonstrated a lower long-term risk of VREs with repair compared with replacement, with low mortality and comparable durability. Further prospective randomized control trials are necessary to formally compare outcomes and determine superiority.

Derivation and validation of a clinical model to predict death or cardiac hospitalizations while on the cardiac surgery waitlist.

BACKGROUND: Waitlist management is a global challenge. For patients with severe cardiovascular diseases awaiting cardiac surgery, prolonged wait times are associated with unplanned hospitalizations. To facilitate evidence-based resource allocation, we derived and validated a clinical risk model to predict the composite outcome of death and cardiac hospitalization of patients on the waitlist for cardiac surgery. METHODS: We used the CorHealth Ontario Registry and linked ICES health care administrative databases, which have information on all Ontario residents. We included patients 18 years or older who waited at home for coronary artery bypass grafting, valvular or thoracic aorta surgeries between 2008 and 2019. The primary outcome was death or an unplanned cardiac hospitalizaton, defined as nonelective admission for heart failure, myocardial infarction, unstable angina or endocarditis. We randomly divided two-thirds of these patients into derivation and one-third into validation data sets. We derived the model using a multivariable Cox proportional hazard model with backward stepwise variable selection. RESULTS: Among 62 375 patients, 41 729 patients were part of the derivation data set and 20 583 were part of the validation data set. Of the total, 3033 (4.9%) died or had an unplanned cardiac hospitalization while waiting for surgery. The area under the curve of our model at 15, 30, 60 and 89 days was 0.85, 0.82, 0.81 and 0.80, respectively, in the derivation cohort and 0.83, 0.80, 0.78 and 0.78, respctively, in the validation cohort. The model calibrated well at all time points. INTERPRETATION: We derived and validated a clinical risk model that provides accurate prediction of the risk of death and unplanned cardiac hospitalization for patients on the cardiac surgery waitlist. Our model could be used for quality benchmarking and data-driven decision support for managing access to cardiac surgery.

Impact of surgeon and anaesthesiologist sex on patient outcomes after cardiac surgery: a population-based study.

BACKGROUND: Effective teamwork between anaesthesiologists and surgeons is essential for optimising patient safety in the cardiac operating room. While many factors may influence the relationship between these two physicians, the role of sex and gender have yet to be investigated. OBJECTIVES: We sought to determine the association between cardiac physician team sex discordance and patient outcomes. DESIGN: We performed a population-based, retrospective cohort study. PARTICIPANTS AND SETTING: Adult patients who underwent coronary artery bypass grafting (CABG) and/or aortic, mitral or tricuspid valve surgery between 2008 and 2018 in Ontario, Canada. PRIMARY AND SECONDARY OUTCOME MEASURES: The primary outcome was all-cause 30-day mortality. Secondary outcomes included major adverse cardiovascular events at 30 days and hospital and intensive care unit lengths of stay (LOS). Mixed effects logistic regression was used for categorical outcomes and Poisson regression for continuous outcomes. RESULTS: 79 862 patients underwent cardiac surgery by 98 surgeons (11.2% female) and 279 anaesthesiologists (23.3% female); 19 893 (24.9%) were treated by sex-discordant physician teams. Physician sex discordance was not associated with overall patient mortality or LOS; however, patients who underwent isolated CABG experienced longer hospital LOS when treated by an all-male physician team as compared with an all-female team (adjusted OR=1.07; p=0.049). When examining the impact of individual physician sex, the length of hospital stay was longer when isolated CABG procedures were attended by a male surgeon (OR=1.10; p=0.004) or anaesthesiologist (OR=1.02; p=0.01). CONCLUSIONS: Patient mortality and length of stay after cardiac surgery may vary by sex concordance of the attending surgeon-anaesthesiologist team. Further research is needed to examine the underlying mechanisms of these observed relationships.

Disability-free survival after major cardiac surgery: a population-based retrospective cohort study.

BACKGROUND: Cardiovascular research has traditionally been dedicated to "tombstone" outcomes, with little attention dedicated to the patient's perspective. We evaluated disability-free survival as a patient-defined outcome after cardiac surgery. METHODS: We conducted a retrospective cohort study of patients aged 40 years and older who underwent coronary artery bypass grafting (CABG) or single or multiple valve (aortic, mitral, tricuspid) surgery in Ontario between Oct. 1, 2008, and Dec. 31, 2016. The primary outcome was disability (a composite of stroke, 3 or more nonelective hospital admissions and admission to a long-term care facility) within 1 year after surgery. We assessed the procedure-specific risk of disability using cumulative incidence functions, and the relative effect of covariates on the subdistribution hazard using Fine and Gray models. RESULTS: The study included 72 824 patients. The 1-year incidence of disability and death was 2431 (4.6%) and 1839 (3.5%) for CABG, 677 (6.5%) and 539 (5.2%) for single valve, 118 (9.0%) and 140 (10.7%) for multiple valve, 718 (9.0%) and 730 (9.2%) for CABG and single valve, and 87 (13.1%) and 94 (14.1%) for CABG and multiple valve surgery, respectively. With CABG as the reference group, the adjusted hazard ratios for disability were 1.34 (95% confidence interval [CI] 1.21-1.48) after single valve, 1.43 (95% CI 1.18-1.75) after multiple valve, 1.38 (95% CI 1.26-1.51) after CABG and single valve, and 1.78 (95% CI 1.43-2.23) after CABG and multiple valve surgery. Combined CABG and multiple valve surgery, heart failure, creatinine 180 µmol/L or greater, alcohol use disorder, dementia and depression were independent risk factors for disability. INTERPRETATION: The cumulative incidence of disability was lowest after CABG and highest after combined CABG and multiple valve surgery. Our findings point to a need for models that predict personalized disability risk to enable better patient-centred care.

Impact of sex on outcomes after percutaneous repair of functional mitral valve regurgitation.

BACKGROUND: The role of percutaneous repair of functional mitral regurgitation (MR) is evolving. Left ventricle remodeling is known to be different between men and women; however, outcomes following percutaneous repair of functional MR have not considered the impact of sex. METHODS: Between 2012 and 2018, 175 patients underwent percutaneous repair of functional MR with the Mitra Clip NT/NTR (Abbott) at our institution. Patients were assessed in a dedicated clinic with a follow-up that averaged 0.7 ± 1.2 years and extended to 5.7 years. RESULTS: Men had a larger body surface area than women (p < .001), and were more likely than women to have diabetes preoperatively (p = .02). There were no deaths or instances of single leaflet detachment. Immediate postprocedure MR was ≤2+ in 158 (90%) with a mean trans-mitral valve repair gradient of 3.4 ± 1.0 and 3.5 ± 2.1 mmHg, respectively for women and men (p = .8). One- and 2-year freedom from MR ≥3+ was 86.0 ± 3.5% and 77.6 ± 5.1%, respectively. After adjusting for differences between male and female patients, women were more likely to have recurrent MR ≥3+ (hazard ratio, 4.7; 95% confidence interval, 1.2-18.4; p = .03). Upon adjusted analysis, there was also no association between gender and survival (p = .2). One- and 2-year survival was 69.8 ± 4.3% and 54.3 ± 5.5%, respectively. CONCLUSION: Women are more likely to have recurrent severe MR after percutaneous repair of functional MR. The mechanism for this remains undetermined.

Derivation of Patient-Defined Adverse Cardiovascular and Noncardiovascular Events Through a Modified Delphi Process.

Importance: There is little evidence to support patient-centered outcomes in patients with cardiovascular disease. Objective: To derive patient-defined adverse cardiovascular and noncardiovascular events (PACE) through a consensus-based process. Design, Setting, and Participants: This pan-Canadian, consensus-based, qualitative study used an iterative Delphi method to achieve consensus within a 35-member panel consisting of patients with cardiovascular diseases and their caregivers and clinicians. The process included 4 rounds of online questionnaires, followed by an in-person final consensus meeting. Data analysis was performed in September 2019. Main Outcomes and Measures: Defining PACE as a 5-item composite outcome. Results: Thirty-five potential panelists consented to participate, including 11 clinicians (8 men [73%]) and 24 patients and caregivers (13 men [54%]). Twenty-nine (83%), 28 (80%), 26 (74%), and 23 (66%) of the panelists participated in each of respective the online rounds. A shortlist of 11 patient-defined items was further refined at the in-person meeting, which 20 of the panelists attended. The PACE definition that was decided through the consensus process was a composite of severe stroke necessitating hospitalization for 14 days or longer or inpatient rehabilitation, ventilator dependence, new onset or worsening heart failure, nursing home admission, or new onset dialysis. Conclusions and Relevance: This study defined PACE as a versatile, patient-centered outcome through a consensus process with input from patients, caregivers, and clinicians. Given the paucity of patient-centered outcomes in cardiovascular research, PACE may be considered as a potential outcome after methodological evaluation of its reliability.

Management and Outcome of Patients Admitted With Tricuspid Regurgitation in France.

BACKGROUND: Growing evidence shows a major outcome impact and undertreatment of tricuspid regurgitation (TR), but large and comprehensive contemporary reports of management and outcome at the nationwide level are lacking. METHODS: We gathered all consecutive patients admitted with a diagnosis of likely functional TR in 2014-2015 in France from the Programme de Médicalisation des Systèmes d'Information national database and collected rate of surgery, in-hospital mortality, 1-year mortality, or heart failure (HF) readmission rates. RESULTS: In 2014-2015, 17,676 consecutive patients (75 ± 14 years of age, 51% female) were admitted with a TR diagnosis. Charlson index was ≥ 2 in 56% of the population and 46% presented with HF. TR was associated with prior cardiac surgery, ischemic/dilated cardiomyopathy, or mitral regurgitation in 73% of patients. Only 10% of TR patients overall and 67% of those undergoing mitral valve surgery received a tricuspid valve intervention. Among the 13,654 (77%) conservatively managed patients, in-hospital mortality, 1-year mortality, and 1-year mortality or HF readmission rates were 5.1%, 17.8%, and 41%, respectively, overall, and 5.3%,17.2%, and 37%, respectively, among those with no underlying medical conditions (8-fold higher than predicted for age and gender). CONCLUSIONS: This nationwide cohort of patients admitted with TR included elderly patients with frequent comorbidities/underlying cardiac diseases. In patients conservatively managed, mortality and morbidity were considerably high over a short time span. Despite this poor prognosis, only 10% of patients underwent a tricuspid valve intervention. These nationwide data showing a considerable risk and potential underuse of treatment highlight the critical need to develop strategies to improve the management and outcomes of TR patients.

Transcatheter Mitral Valve Repair in Cardiogenic Shock and Mitral Regurgitation: A Patient-Level, Multicenter Analysis.

OBJECTIVES: The aim of this study was to evaluate the outcome of transcatheter mitral valve repair (TMVr) in patients with cardiogenic shock and significant mitral regurgitation (MR). BACKGROUND: Patients in cardiogenic shock with severe MR have a poor prognosis in the setting of conventional medical therapy. Because of its favorable safety profile, TMVr is being increasingly used as an acute therapy in this population, though its efficacy remains unknown. METHODS: A multicenter, collaborative, patient-level analysis was conducted. Patients with cardiogenic shock and moderate to severe (3+) or severe (4+) MR who were not surgical candidates were treated with TMVr. The primary outcome was in-hospital mortality. Secondary outcomes included 90-day mortality, heart failure (HF) hospitalization, and the combined event rate of 90-day mortality and HF hospitalization following dichotomization by TMVr device success. RESULTS: Between January 2011 and February 2019, 141 patients across 14 institutions met the inclusion criteria. In-hospital mortality occurred in 22 patients (15.6%), at 90 days in 38 patients (29.5%), and at one year in 55 patients (42.6%). Median length of hospital stay following TMVr was 10 days (interquartile range: 6 to 20 days). HF hospitalization occurred in 26 patients (18.4%) at a median of 73 days (interquartile range: 26 to 546 days). When stratified by TMVr procedural results, successful TMVr reduced rates of in-hospital mortality (hazard ratio [HR]: 0.36; 95% confidence interval [CI]: 0.13 to 0.98; p = 0.04), 90-day mortality (HR: 0.36; 95% CI: 0.16 to 0.78; p = 0.01), and the composite of 90-day mortality and HF hospitalization (HR: 0.41; 95% CI: 0.19 to 0.90; p = 0.03). CONCLUSIONS: TMVr may improve short- and intermediate-term mortality in high-risk patients with cardiogenic shock and moderate to severe MR. Randomized studies are needed to definitively establish MR as a therapeutic target in patients with cardiogenic shock.

Correction of Bileaflet Mitral Valve Prolapse Through Reduction of Posterior Leaflet Height.

Mitral regurgitation due to bileaflet prolapse can be corrected with height reduction of the posterior leaflet through detachment at its base, division of accompanying secondary chordae, and leaflet-annular reapproximation. This technique lowers the posterior leaflet height to approximately 1.5 cm, thereby displacing the line of coaptation posteriorly to achieve symmetry without the need for additional artificial chordae. Of 37 patients who underwent this type of repair at our institution, no patient had recurrent mitral regurgitation ≥ 2 at an average follow-up of 1.9 years (range, 0.2-4.5).

Randomized, Controlled Trial Comparing Mitral Valve Repair With Leaflet Resection Versus Leaflet Preservation on Functional Mitral Stenosis: The CAMRA CardioLink-2 Study.

BACKGROUND: Equipoise exists between the use of leaflet resection and preservation for surgical repair of mitral regurgitation caused by prolapse. We therefore performed a randomized, controlled trial comparing these 2 techniques, particularly in regard to functional mitral stenosis. METHODS: One hundred four patients with degenerative mitral regurgitation surgically amenable to either leaflet resection or preservation were randomized at 7 specialized cardiac surgical centers. Exclusion criteria included anterior leaflet or commissural prolapse, as well as a mixed cause for mitral valve disease. Using previous data, we determined that a sample size of 88 subjects would provide 90% power to detect a 5-mm Hg difference in mean mitral valve gradient at peak exercise, assuming an SD of 6.7 mm with a 2-sided test with α=5% and 10% patient attrition. The primary end point was the mean mitral gradient at peak exercise 12 months after repair. RESULTS: Patient age, proportion who were female, and Society of Thoracic Surgeons risk score were 63.9±10.4 years, 19%, and 1.4±2.8% for those who were assigned to leaflet resection (n=54), and 66.3±10.8 years, 16%, and 1.9±2.6% for those who underwent leaflet preservation (n=50). There were no perioperative deaths or conversions to replacement. At 12 months, moderate mitral regurgitation was observed in 3 subjects in the leaflet resection group and 2 in the leaflet preservation group. The mean transmitral gradient at 12 months during peak exercise was 9.1±5.2 mm Hg after leaflet resection and 8.3±3.3 mm Hg after leaflet preservation (P=0.43). The participants had similar resting peak (8.3±4.4 mm Hg versus 8.4±2.6 mm Hg; P=0.96) and mean resting (3.2±1.9 mm Hg versus 3.1±1.1 mm Hg; P=0.67) mitral gradients after leaflet resection and leaflet preservation, respectively. The 6-minute walking distance was 451±147 m for those in the leaflet resection versus 481±95 m for the leaflet preservation group (P=0.27). CONCLUSIONS: In this adequately powered randomized trial, repair of mitral prolapse with either leaflet resection or leaflet preservation was associated with similar transmitral gradients at peak exercise at 12 months postoperatively. These data do not support the hypothesis that a strategy of leaflet resection (versus preservation) is associated with a risk of functional mitral stenosis. Registration: URL: https://www.clinicaltrials.gov; Unique identifier NCT02552771.