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.

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.

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.

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.

Derivation and Validation of a Clinical Model to Predict Intensive Care Unit Length of Stay After Cardiac Surgery.

Background Across the globe, elective surgeries have been postponed to limit infectious exposure and preserve hospital capacity for coronavirus disease 2019 (COVID-19). However, the ramp down in cardiac surgery volumes may result in unintended harm to patients who are at high risk of mortality if their conditions are left untreated. To help optimize triage decisions, we derived and ambispectively validated a clinical score to predict intensive care unit length of stay after cardiac surgery. Methods and Results Following ethics approval, we derived and performed multicenter valida tion of clinical models to predict the likelihood of short (≤2 days) and prolonged intensive care unit length of stay (≥7 days) in patients aged ≥18 years, who underwent coronary artery bypass grafting and/or aortic, mitral, and tricuspid value surgery in Ontario, Canada. Multivariable logistic regression with backward variable selection was used, along with clinical judgment, in the modeling process. For the model that predicted short intensive care unit stay, the c-statistic was 0.78 in the derivation cohort and 0.71 in the validation cohort. For the model that predicted prolonged stay, c-statistic was 0.85 in the derivation and 0.78 in the validation cohort. The models, together termed the CardiOttawa LOS Score, demonstrated a high degree of accuracy during prospective testing. Conclusions Clinical judgment alone has been shown to be inaccurate in predicting postoperative intensive care unit length of stay. The CardiOttawa LOS Score performed well in prospective validation and will complement the clinician's gestalt in making more efficient resource allocation during the COVID-19 period and beyond.

The Impact of Preoperative Risk on the Association between Hypotension and Mortality after Cardiac Surgery: An Observational Study.

BACKGROUND: Despite steady improvements in cardiac surgery-related outcomes, our understanding of the physiologic mechanisms leading to perioperative mortality remains incomplete. Intraoperative hypotension is an important risk factor for mortality after noncardiac surgery but remains relatively unexplored in the context of cardiac surgery. We examined whether the association between intraoperative hypotension and in-hospital mortality varied by patient and procedure characteristics, as defined by the validated Cardiac Anesthesia Risk Evaluation (CARE) mortality risk score. METHODS: We conducted a retrospective cohort study of consecutive adult patients who underwent cardiac surgery requiring cardiopulmonary bypass (CPB) from November 2009-March 2015. Those who underwent off-pump, thoracic aorta, transplant and ventricular assist device procedures were excluded. The primary outcome was in-hospital mortality. Hypotension was categorized by mean arterial pressure (MAP) of <55 and between 55-64 mmHg before, during and after CPB. The relationship between hypotension and death was modeled using multivariable logistic regression in the intermediate and high-risk groups. RESULTS: Among 6627 included patients, 131 (2%) died in-hospital. In-hospital mortality in patients with CARE scores of 1, 2, 3, 4 and 5 was 0 (0%), 7 (0.3%), 35 (1.3%), 41 (4.6%) and 48 (13.6%), respectively. In the intermediate-risk group (CARE = 3-4), MAP < 65 mmHg post-CPB was associated with increased odds of death in a dose-dependent fashion (adjusted OR 1.30, 95% CI 1.13-1.49, per 10 min exposure to MAP < 55 mmHg, p = 0.002; adjusted OR 1.18 [1.07-1.30] per 10 min exposure to MAP 55-64 mmHg, p = 0.001). We did not observe an association between hypotension and mortality in the high-risk group (CARE = 5). CONCLUSIONS: Post-CPB hypotension is a potentially modifiable risk factor for mortality in intermediate-risk patients. Our findings provide impetus for clinical trials to determine if hemodynamic goal-directed therapies could improve survival in these patients.

Sex Differences in Long-Term Survival After Major Cardiac Surgery: A Population-Based Cohort Study.

Background Little attention has been paid to the importance of sex in the long-term prognosis of patients undergoing cardiac surgery. Methods and Results We conducted a retrospective cohort study of Ontario residents, aged ≥40 years, who underwent coronary artery bypass grafting (CABG) and/or aortic, mitral, or tricuspid valve surgery between October 1, 2008, and December 31, 2016. The primary outcome was all-cause mortality. The mortality rate in each surgical group was calculated using the Kaplan-Meier method. The risk of death was assessed using multivariable Cox proportional hazard models. Sex-specific mortality risk factors were identified using multiplicative interaction terms. A total of 72 824 patients were included in the study (25% women). The median follow-up period was 5 (interquartile range, 3-7) years. The long-term age-standardized mortality rate was lowest in patients who underwent isolated CABG and highest among those who underwent combined CABG/multiple valve surgery. Women had significantly higher age-standardized mortality rate than men after CABG and combined CABG/mitral valve surgery. Men had lower rates of long-term mortality than women after isolated mitral valve repair, whereas women had lower rates of long-term mortality than men after isolated mitral valve replacement. We observed a statistically significant association between female sex and long-term mortality after adjustment for key risk factors. Conclusions Female sex was associated with long-term mortality after cardiac surgery. Perioperative optimization and long-term follow-up should be tailored to younger women with a history of myocardial infarction and percutaneous coronary intervention and older men with a history of chronic obstructive pulmonary disease and depression.

Eight-year follow-up of the Clopidogrel After Surgery for Coronary Artery Disease (CASCADE) trial.

OBJECTIVE: In this 8 years' follow-up study, we evaluated the long-term outcomes of the addition of clopidogrel to aspirin during the first year after coronary artery bypass grafting, versus aspirin plus placebo, with respect to survival, major adverse cardiac, or major cerebrovascular events, including revascularization, functional status, graft patency, and native coronary artery disease progression. METHODS: In the initial Clopidogrel After Surgery for Coronary Artery Disease trial, 113 patients were randomized to receive either daily clopidogrel (n = 56) or placebo (n = 57), in addition to aspirin, in a double-blind fashion for 1 year after coronary artery bypass grafting. All patients were re-evaluated to collect long-term clinical data. Surviving patients with a glomerular filtration rate > 30 mL/min were asked to undergo a coronary computed tomography angiogram to evaluate the late saphenous vein graft patency and native coronary artery disease progression. RESULTS: At a median follow-up of 7.6 years, survival rate was 85.5% ± 3.8% (P = .23 between the 2 groups). A trend toward enhanced freedom from all-cause death or major adverse cardiac or cerebrovascular events, including revascularization, was observed in the aspirin-clopidogrel group (P = .11). No difference in functional status or freedom from angina was observed between the 2 groups (P > .57). The long-term patency of saphenous vein graft was 89.11% in the aspirin-clopidogrel group versus 91.23% in the aspirin-placebo group (P = .79). A lower incidence of moderate to severe native disease progression was observed in the aspirin-clopidogrel group versus the aspirin-placebo group (7 out of 122 vs 13 out of 78 coronary segments that showed progression, respectively [odds ratio, 0.3 ± 0.2; 95% confidence interval, 0.1-0.8; P = .02]). CONCLUSIONS: At 8 years' follow-up, the addition of clopidogrel to aspirin during the first year after coronary artery bypass grafting exhibited a lower incidence of moderate to severe progression of native coronary artery disease and a trend toward higher freedom from major adverse cardiac or cerebrovascular events, including revascularization, or death in the aspirin-clopidogrel group. CLINICAL TRIAL REGISTRATION: http://www.clinicaltrials.gov. Unique identifier: NCT00228423.

Randomised trial of mitral valve repair with leaflet resection versus leaflet preservation on functional mitral stenosis (The CAMRA CardioLink-2 Trial).

BACKGROUND: The gold-standard treatment of severe mitral regurgitation (MR) due to degenerative disease is valve repair, which is surgically performed with either a leaflet resection or leaflet preservation approach. Recent data suggest that functional mitral stenosis (MS) may occur following valve repair using a leaflet resection strategy, which adversely affects patient prognosis. A randomised comparison of these two approaches to mitral repair on functional MS has not been conducted. METHODS AND ANALYSIS: This is a prospective, multicentre randomised controlled trial designed to test the hypothesis that leaflet preservation leads to better preservation of mitral valve geometry, and therefore, will be superior to leaflet resection for the primary outcome of functional MS as assessed by 12-month mean mitral valve gradient at peak exercise. Eighty-eight patients with posterior leaflet prolapse will be randomised intraoperatively once deemed by the operating surgeon to feasibly undergo mitral repair using either a leaflet resection or leaflet preservation approach. Secondary end points include comparison of repair strategies with regard to mitral valve orifice area, leaflet coaptation height, 6 min walk test and a composite major adverse event end point consisting of recurrent MR ≥2+, death or hospital readmission for congestive heart failure within 12 months of surgery. ETHICS AND DISSEMINATION: Institutional ethics approval has been obtained from all enrolling sites. Overall, there remains clinical equipoise regarding the mitral valve repair strategy that is associated with the least likelihood of functional MS. This trial hopes to introduce high-quality evidence to help surgical decision making in this context. TRIAL REGISTRATION NUMBER: NCT02552771.

When Should the Mitral Valve Be Repaired or Replaced in Patients With Ischemic Mitral Regurgitation?

BACKGROUND: Data comparing outcomes after repair versus replacement of chronic ischemic mitral regurgitation (MR) is evolving. Recent data suggest that repair is associated with recurrent MR, but not survival, when compared with replacement. However, it remains unclear when either surgical strategy should be applied based on preoperative mitral valve anatomy. METHODS: Between 2001 and 2013, 161 patients underwent repair or replacement of chronic ischemic MR. The mean age of these patients was 68.2 ± 9.0 years, 44 (27%) were female, and concomitant coronary artery bypass grafting was performed in 126 (78%). The mean preoperative posterior leaflet angle was 27.7 ± 14.2 degrees, and the left ventricular ejection fraction was 41.2 ± 12.4%. Detailed preoperative assessments of mitral valve anatomy were determined by transesophageal echocardiography. Clinical and echocardiographic follow-up was for 4.6 ± 3.2 years and extended to 11.7 years. RESULTS: Overall, perioperative death occurred in 6 (3.3%) patients; 2 patients died after valve repair and 4 after valve replacement. Five-year survival and freedom from recurrent MR (≥2+) rates were 74.0 ± 5.6% and 57.8 ± 8.0%, respectively, after valve repair and 69.4 ± 6.2% and 87.1 ± 7.0%, respectively, after valve replacement. Valve repair was associated with recurrent MR (≥2+) (hazard ratio [HR], 5.3 ± 3.3; p = 0.007), but not survival (HR, 0.9 ± 0.3; p = 0.8). Preoperative posterior leaflet tethering angle was associated with survival (HR, 1.09 ± 0.04; p = 0.005) and also recurrent MR (≥2+) (HR, 1.04 ± 0.02; p = 0.03) after valve repair. Based on a receiver operator curve describing the relationship between recurrent MR (≥2+) and posterior leaflet tethering angle, a threshold of 22 degrees was determined. CONCLUSIONS: Surgical correction of chronic ischemic MR can be performed with favorable early and late results, although recurrent MR occurred more often after repair. Among patients who underwent repair of ischemic MR, a preoperative posterior leaflet tethering angle of 22 degrees or greater was associated with worse late outcomes.

How Does Mitral Valve Repair Fail in Patients With Prolapse?-Insights From Longitudinal Echocardiographic Follow-Up.

BACKGROUND: Repair of mitral regurgitation (MR) caused by prolapse has been well validated. Although favorable early and late results after repair have been reported, few data are available that mechanistically describe how a mitral repair fails beyond the mere need for mitral valve reoperation. We therefore sought to determine the modes of valve repair failure in patients who underwent surgical correction of MR caused by prolapse. METHODS: Between 2001 and 2015, 855 patients underwent repair of MR caused by prolapse. Patients were a mean age of 63.7 ± 12.7 years, and 380 (44%) had bileaflet prolapse. The overall repair rate was 97.2%. These patients were monitored as part of a cohort initiative and underwent serial clinical and echocardiographic assessments at 1, 3 to 6, and 12 months after the operation. Beyond the first year of the MR repair, patients were assessed by echocardiography every 1 to 2 years or when clinically indicated. Clinical and echocardiographic follow-up averaged 4.3 ± 3.5 years. RESULTS: Freedom from recurrent MR of 2+ or higher was 92.4% ± 1.3% at 5 years and 86.6% ± 2.4% at 10 years. Overall, recurrent MR of 2+ or higher developed in 49 patients (5.7%) at a mean of 3.1 ± 2.5 years after the repair, of whom 14 (1.6%) had recurrent MR of 3+ or 4+. Among patients with bileaflet prolapse, recurrent MR of 2+ or higher was observed in 24, of whom 9 had 3+ or 4+ MR., The development of recurrent MR of 2+ or higher was categorized as prolapse in 6 and nonprolapse in 43. Severe mitral stenosis occurred in 3 patients at 8.2 years after the MR repair. Mitral reoperation was ultimately performed in 21 patients. Patients who had recurrent MR 2+ or higher within the first year after the operation were more likely to undergo a subsequent mitral valve reoperation (incident rate ratio, 5.2 ± 2.9; p = 0.003), although no association between recurrent MR and reoperation was observed after the first year. CONCLUSIONS: Severe MR after repair is rare, although some may have recurrent moderate MR. Patients who required a subsequent mitral valve reoperation were most likely to have recurrent MR of 2+ or higher within the first year after the operation.

Determinants of late outcomes in women undergoing mitral repair of myxomatous degeneration.

OBJECTIVES: Studies have consistently shown that women have worse perioperative outcomes following mitral surgery compared with men. Few data are available that explain these divergent outcomes. This study was conducted to determine whether women with degenerative mitral valve disease present to surgery with more advanced disease than men, and to determine whether these differences influence long-term clinical outcomes. METHODS: Seven hundred and forty-three patients underwent repair of mitral regurgitation due to myxomatous degeneration between 2001 and 2014. Of these, 208 (28%) were females and concomitant coronary bypass grafting was performed in 103 (14%). The mean clinical follow-up was for 3.1 years, and extended to 11.9 years. RESULTS: Perioperative mortality was 0.1%. Preoperatively, women had a larger indexed left atrial diameter (27.9 ± 5.7 vs 25.3 ± 4.7 mm/m2, P = 0.0001), larger indexed left ventricle end-systolic dimension (20.6 ± 5.5 vs 18.7 ± 5.1 mm/m2, P = 0.028) and higher right ventricular systolic pressure (44.4 ± 14.4 vs 41.7 ± 13.3 mmHg, P = 0.026) compared with men. Five-year survival and freedom from recurrent MR ≥2+ were 88.7 ± 1.8 and 90.7 ± 1.6%, respectively. Although gender was not associated with survival (hazard ratio: 1.04 ± 0.4, P = 0.91), women were more likely to develop recurrent MR ≥2+ at follow-up compared with men (hazard ratio: 1.9 ± 0.5, P = 0.007). CONCLUSIONS: In this large series, women with degenerative mitral valve disease presented with echocardiographic markers suggestive of more advanced disease at the time of surgery. Although there was no difference in early or late survival between groups, women were more likely to develop recurrent MR ≥2+ over the course of follow-up. Earlier surgical referral of women may, therefore, be advised.