2024 Update of The Society of Thoracic Surgeons Short-term Esophagectomy Risk Model: More Inclusive and Improved Calibration.

BACKGROUND: The Society of Thoracic Surgeons General Thoracic Surgery Database (STS-GTSD) previously reported short-term risk models for esophagectomy for esophageal cancer. We sought to update existing models using more inclusive contemporary cohorts, with consideration of additional risk factors based on clinical evidence. METHODS: The study population consisted of adult patients in the STS-GTSD who underwent esophagectomy for esophageal cancer between January 2015 and December 2022. Separate esophagectomy risk models were derived for 3 primary end points: operative mortality, major morbidity, and composite morbidity or mortality. Logistic regression with backward selection was used, with predictors retained in models if P < .10. All derived models were validated using 9-fold cross-validation. Model discrimination and calibration were assessed for the overall cohort and specified subgroups. RESULTS: A total of 18,503 patients from 254 centers underwent esophagectomy for esophageal cancer. Operative mortality, morbidity, and composite morbidity or mortality rates were 3.4%, 30.5%, and 30.9%, respectively. Novel predictors of short-term outcomes in the updated models included body surface area and insurance payor type. Overall discrimination was similar or superior to previous STS-GTSD models for operative mortality (C statistic = 0.72) and for composite morbidity or mortality (C statistic = 0.62), Model discrimination was comparable across procedure- and demographic-specific subcohorts. Model calibration was excellent in all patient subgroups. CONCLUSIONS: The newly derived esophagectomy risk models showed similar or superior performance compared with previous models, with broader applicability and clinical face validity. These models provide robust preoperative risk estimation and can be used for shared decision making, assessment of provider performance, and quality improvement.

Reoperations in Adolescents and Adults After Prior Arterial Switch Operation: The Society of Thoracic Surgeons Congenital Heart Surgery Database Analysis.

BACKGROUND: Arterial switch operation (ASO) has supplanted physiologic repairs for transposition of the great arteries and related anomalies. As survival rates have increased, so has the potential need for cardiac reoperations to address ASO-related complications arising later in life. METHODS: The Society of Thoracic Surgeons Congenital Heart Surgery Database (2010-2021) was reviewed to assess prevalence and types of cardiac reoperations for patients aged ≥10 years with prior ASO for transposition of the great arteries or double-outlet right ventricle/transposition of the great arteries type. A hierarchical stratification designating 13 procedure categories was established a priori by investigators. Each eligible surgical hospitalization was assigned to the single highest applicable hierarchical category. Outcomes were compared across procedure categories, excluding hospitalizations limited to pacemaker-only and mechanical circulatory support-only procedures. Variation during the study period in relative proportions of left heart vs non-left heart procedure category encounters was assessed. RESULTS: There were 698 cardiac surgical hospitalizations for patients aged 10 to 35 years at 100 centers. The most common left heart procedure categories were aortic valve procedures (n = 146), aortic root procedures (n = 117), and coronary artery procedures (n = 40). Of 619 hospitalizations eligible for outcomes analysis, major complications occurred in 11% (67/619). Discharge mortality was 2.3% (14/619). Year-by-year analysis of surgical hospitalizations reveals substantial growth in numbers for the aggregate of all procedure categories. Growth in relative proportions of left heart vs non-left heart procedures was significant (P = .0029; Cochran-Armitage trend test). CONCLUSIONS: This large multicenter study of post-ASO reoperations beyond early childhood documents year-over-year growth in total reoperations. Left-sided heart procedures recently had the highest rate of rise. These observations have implications for counseling, surveillance, and management.

Operating Room Extubation for Patients Undergoing Cardiac Surgery: A National Society of Thoracic Surgeons Database Analysis.

BACKGROUND: The utility of operating room extubation (ORE) after cardiac surgery over fast-track extubation (FTE) within 6 hours remains contested. We hypothesized ORE would be associated with equivalent rates of morbidity and mortality, relative to FTE. METHODS: Patients undergoing nonemergent cardiac surgery were identified in The Society of Thoracic Surgeons Adult Cardiac Surgery Database between July 2017 and December 2022. Only procedures with The Society of Thoracic Surgeons risk models were included. Risk-adjusted outcomes of ORE and FTE were compared by observed-to-expected ratios with 95% CIs aggregated over all procedure types, and ORE vs FTE adjusted odds ratios (ORs) specific to each procedure type using multivariable logistic regression. Analyzed outcomes were operative mortality, prolonged length of stay, composite reoperation for bleeding and reintubation, and composite morbidity and mortality. RESULTS: The study population of 669,099 patients across 1069 hospitals included 36,298 ORE patients in 296 hospitals. Risk-adjusted analyses found that ORE was associated with statistically similar or better results across each of the 4 outcomes and procedure subtypes. Notably, rates of postoperative mortality were significantly lower in ORE patients undergoing coronary artery bypass grafting (OR, 0.54; 95% CI, 0.46-0.65), aortic valve replacement (OR, 0.43; 95% CI, 0.24-0.77), and mitral valve replacement (OR, 0.48; 95% CI, 0.26-0.89). CONCLUSIONS: Extubation in the OR was safe and effective in a selected patient population and may be associated with superior outcomes in coronary artery bypass, aortic valve replacement, and mitral valve replacement. These national data appear to confirm institutional experiences regarding the potential benefit of OR extubation. Further refinement of optimal populations may justify randomized investigation.

Cardiac Surgery After Transcatheter Aortic Valve Replacement: Trends and Outcomes.

BACKGROUND: Reports of cardiac operations after transcatheter aortic valve replacement (TAVR) and early TAVR explantation are increasing. The purpose of this report is to document trends and outcomes of cardiac surgery after initial TAVR. METHODS: The Society of Thoracic Surgeons Adult Cardiac Surgery Database was queried for all adult patients undergoing cardiac surgery after a previously placed TAVR between January 2012 and March 2023. This identified an overall cohort and 2 subcohorts: nonaortic valve operations and surgical aortic valve replacement (SAVR) after previous TAVR. Cohorts were examined with descriptive statistics, trend analyses, and 30-day outcomes. RESULTS: Of 5457 patients who were identified, 2485 (45.5%) underwent non-SAVR cardiac surgery, and 2972 (54.5%) underwent SAVR. The frequency of cardiac surgery after TAVR increased 4235.3% overall and 144.6% per year throughout the study period. The incidence of operative mortality and stroke were 15.5% and 4.5%, respectively. Existing The Society of Thoracic Surgeons risk models performed poorly, because observed-to-expected mortality ratios were significantly >1.0. Among those undergoing SAVR after TAVR, increasing preoperative surgical urgency, age, dialysis, need for SAVR, and concomitant procedures were associated with increased mortality, whereas type of TAVR explant was not. CONCLUSIONS: The need for cardiac surgery, including redo SAVR after TAVR, is increasing rapidly. Risks are higher, and outcomes are worse than predicted. These data should closely inform heart team decisions if TAVR is considered at lowering age and risk profiles in the absence of longitudinal evidence.

Intraoperative Anemia Mediates Sex Disparity in Operative Mortality After Coronary Artery Bypass Grafting.

BACKGROUND: Women undergoing coronary artery bypass grafting (CABG) have higher operative mortality than men. OBJECTIVES: The purpose of this study was to evaluate the relationship between intraoperative anemia (nadir intraoperative hematocrit), CABG operative mortality, and sex. METHODS: This was a cohort study of 1,434,225 isolated primary CABG patients (344,357 women) from the Society of Thoracic Surgeons Adult Cardiac Surgery Database (2011-2022). The primary outcome was operative mortality. The attributable risk (AR) (the risk-adjusted strength of the association of female sex with CABG outcomes) for the primary outcome was calculated. Causal mediation analysis derived the total effect of female sex on operative mortality risk and the proportion of that effect mediated by intraoperative anemia. RESULTS: Women had lower median nadir intraoperative hematocrit (22.0% [Q1-Q3: 20.0%-25.0%] vs 27.0% [Q1-Q3: 24.0%-30.0%], standardized mean difference 97.0%) than men. Women had higher operative mortality than men (2.8% vs 1.7%; P < 0.001; adjusted OR: 1.36; 95% CI: 1.30-1.41). The AR of female sex for operative mortality was 1.21 (95% CI: 1.17-1.24). After adjusting for nadir intraoperative hematocrit, AR was reduced by 43% (1.12; 95% CI: 1.09-1.16). Intraoperative anemia mediated 38.5% of the increased mortality risk associated with female sex (95% CI: 32.3%-44.7%). Spline regression showed a stronger association between operative mortality and nadir intraoperative hematocrit at hematocrit values <22.0% (P < 0.001). CONCLUSIONS: The association of female sex with increased CABG operative mortality is mediated to a large extent by intraoperative anemia. Avoiding nadir intraoperative hematocrit values below 22.0% may reduce sex differences in CABG operative mortality.

Multiarterial vs Single-Arterial Coronary Surgery: 10-Year Follow-up of 1 Million Patients.

BACKGROUND: Although many options exist for multivessel coronary revascularization, controversy persists over whether multiarterial grafting (MAG) confers a survival advantage over single-arterial grafting (SAG) with saphenous vein in coronary artery bypass grafting (CABG). This study sought to compare longitudinal survival between patients undergoing MAG and those undergoing SAG. METHODS: All patients undergoing isolated CABG with ≥2 bypass grafts in The Society of Thoracic Surgeons Adult Cardiac Surgery Database (2008-2019) were linked to the National Death Index. Risk adjustment was performed using inverse probability weighting and multivariable modeling. The primary end point was longitudinal survival. Subpopulation analyses were performed and volume thresholds were analyzed to determine optimal benefit. RESULTS: A total of 1,021,632 patients underwent isolated CABG at 1108 programs (100,419 MAG [9.83%]; 920,943 SAG [90.17%]). Median follow-up was 5.30 years (range, 0-12 years). After risk adjustment, all characteristics were well balanced. At 10 years, MAG was associated with improved unadjusted (hazard ratio, 0.59; 95% CI 0.58-0.61) and adjusted (hazard ratio, 0.86; 95% CI, 0.85-0.88) 10-year survival. Center volume of ≥10 MAG cases/year was associated with benefit. MAG was associated with an overall survival advantage over SAG in all subgroups, including stable coronary disease, acute coronary syndrome, and acute infarction. Survival was equivalent to that with SAG for patients age ≥80 years and those with severe heart failure, renal failure, peripheral vascular disease, or obesity. Only patients with a body mass index ≥40 kg/m2 had superior survival with SAG. CONCLUSIONS: Multiarterial CABG is associated with superior long-term survival and should be the surgical multivessel revascularization strategy of choice for patients with a body mass index of less than 40 kg/m2.

Age-Stratified Surgical Aortic Valve Replacement for Aortic Stenosis.

BACKGROUND: The management of aortic stenosis has evolved to stratification by age as reflected in recent societal guidelines. We evaluated age-stratified surgical aortic valve replacement (SAVR) trends and outcomes in patients with bicuspid aortic valve (BAV) or tricuspid aortic valve (TAV) from The Society of Thoracic Surgeons Adult Cardiac Surgery Database. METHODS: This cohort included adults (≥18 years) undergoing SAVR for severe aortic stenosis between July 2011 and December 2022. Comparisons were stratified by age (<65 years, 65-79 years, ≥80 years) and BAV or TAV status. Primary end points included operative mortality, composite morbidity and mortality, and permanent stroke. Observed to expected ratios by The Society of Thoracic Surgeons predicted risk of mortality were calculated. RESULTS: In total, 200,849 SAVR patients (55,326 BAV [27.5%], 145,526 TAV [72.5%]) from 1238 participating hospitals met study criteria. Annual SAVR volumes decreased by 45% (19,560 to 10,851) during the study period. The decrease was greatest (96%) for patients ≥80 years of age (4914 to 207). The relative prevalence of BAV was greater in younger patients (<65 years, 69,068 [49.5% BAV]; 65-79 years, 104,382 [19.1% BAV]; ≥80 years, 27,399 [4.5% BAV]). The observed mortality in <80-year-old BAV patients (<65 years, 1.08; 65-79 years, 1.21; ≥80 years, 3.68) was better than the expected mortality rate (<65 years, 1.22; 65-79 years, 1.54; ≥80 years, 3.14). CONCLUSIONS: SAVR volume in the transcatheter era has decreased substantially, particularly for patients ≥80 years old and for those with TAV. Younger patients with BAV have better than expected outcomes, which should be carefully considered during shared decision-making in the treatment of aortic stenosis. SAVR should remain the preferred therapy in this population.

Contemporary Applications and Outcomes of Pulmonary Artery Banding: An Analysis of The Society of Thoracic Surgeons Congenital Heart Surgery Database.

BACKGROUND: Pulmonary artery banding (PAB) in isolation or combined with a congenital cardiac surgical procedure is common and has important mortality. We aimed to determine patient characteristics, clinical outcomes, variation in clinical outcomes by diagnoses, and center variation in PAB use. METHODS: Using The Society of Thoracic Surgeons Congenital Heart Surgery Database (STS CHSD), this study evaluated outcomes of patients undergoing PAB across diagnoses, participating centers, and additional procedures. Patients were identified by procedure and diagnosis codes from 2016 to 2019. We separated patients into groups of main and bilateral PAB and described their outcomes, focusing on patients with main PAB. RESULTS: This study identified 3367 PAB procedures from 2016 to 2019 (3% of all STS CHSD cardiovascular cases during this period): 2677 main PAB, 690 bilateral PAB. Operative mortality was 8% after main PAB and 26% after bilateral PAB. There was significant variation in use of main PAB by center, with 115 centers performing at least 1 main PAB procedure (range, 1-134; Q1-Q3, 8-33). For patients with main PAB, there were substantial differences in mortality, depending on timing of main PAB relative to other procedures. The highest operative mortality (25%; P < .0001) was in patients who underwent main PAB after another separate procedure during their admission, with extracorporeal membrane oxygenation being the most frequent preceding procedure. CONCLUSIONS: PAB is a frequently used congenital cardiac procedure with high mortality and variation in use across centers. Outcomes vary widely by banding type and patient diagnosis. Main PAB after cardiac surgical procedures, especially extracorporeal membrane oxygenation, is associated with very high operative mortality.

Robotic Mitral Valve Repair for Degenerative Mitral Regurgitation.

BACKGROUND: Contemporary national utilization and comparative safety data of robotic mitral valve repair for degenerative mitral regurgitation compared with nonrobotic approaches are lacking. The study aimed to characterize national trends of utilization and outcomes of robotic mitral repair of degenerative mitral regurgitation compared with sternotomy and thoracotomy approaches. METHODS: Patients undergoing intended mitral repair of degenerative mitral regurgitation in The Society of Thoracic Surgeons Adult Cardiac Surgery Database between 2015 and 2021 were examined. Mitral repair was performed in 61,322 patients. Descriptive analyses characterized center-level volumes and outcomes. Propensity score matching separately identified 5540 pairs of robotic vs thoracotomy approaches and 6962 pairs of robotic vs sternotomy approaches. Outcomes were operative mortality, composite mortality and major morbidity, postoperative length of stay, and conversion to mitral replacement. RESULTS: Through the 7-year study period, 116 surgeons across 103 hospitals performed mitral repair robotically. The proportion of robotic cases increased from 10.9% (949 of 8712) in 2015 to 14.6% (1274 of 8730) in 2021. In both robotic-thoracotomy and robotic-sternotomy matched pairs, mortality and morbidity were not significantly different, whereas the robotic approach had lower conversion (1.2% vs 3.1% for robotic-thoracotomy and 1.0% vs 3.7% for robotic-sternotomy), shorter length of stay, and fewer 30-day readmissions. Mortality and morbidity were lower at higher-volume centers, crossing the national mean mortality and morbidity at a cumulative robotic mitral repair case of 40. CONCLUSIONS: Robotic mitral repair is a safe and effective approach and is associated with comparable mortality and morbidity, a lower conversion rate, a shorter length of stay, and fewer 30-day readmissions than thoracotomy or sternotomy approaches.

Outcomes of the Kawashima: A Society of Thoracic Surgeons Congenital Heart Surgery Database Analysis.

BACKGROUND: We aimed to evaluate the effect of age at operation on postoperative outcomes in children undergoing a Kawashima operation. METHODS: The Society of Thoracic Surgeons Congenital Heart Surgery Database was queried for Kawashima procedures from January 1, 2014, to June 30, 2020. Patients were stratified by age at operation in months: 0 to <4, 4 to <8, 8 to <12, and >12. Subsequently, outcomes for those in whom the Kawashima was not the index operation and for those undergoing hepatic vein incorporation (Fontan completion or hepatic vein-to-azygos vein connection) were evaluated. RESULTS: We identified 253 patients who underwent a Kawashima operation (median age, 8.6 months; median weight, 7.4 kg): 12 (4.7%), 0 to <4 months; 96 (37.9%), 4 to <8 months; 81 (32.0%), 8 to <12 months; and 64 (25.3%), >12 months. Operative mortality was 0.8% (n = 2), with major morbidity or mortality in 17.4% (n = 44), neither different across age groups. Patients <4 months had a longer postoperative length of stay (12.5 vs 9.3 days; P = .03). The Kawashima was not the index operation of the hospital admission in 15 (5.9%); these patients were younger (6.0 vs 8.4 months; P = .05) and had more preoperative risk factors (13/15 [92.9%] vs 126/238 [52.9%]; P < .01). We identified 173 patients undergoing subsequent hepatic vein incorporation (median age, 3.9 years; median weight, 15.0 kg) with operative mortality in 6 (3.5%) and major morbidity or mortality in 30 (17.3%). CONCLUSIONS: The Kawashima is typically performed between 4 and 12 months with low mortality. Morbidity and mortality were not affected by age. Hepatic vein incorporations may be higher risk than in traditional Fontan procedures, and ways to mitigate this should be sought.

Practice makes perfect? Institutional coronary artery bypass case volumes and outcomes.

OBJECTIVES: Older studies of coronary artery bypass grafting (CABG) institutional case volumes and outcomes reported conflicting results. We explored this association in the rapidly changing contemporary practice of American surgeons using the Society of Thoracic Surgeons (STS) Adult Cardiac Surgery Database. METHODS: The 2018-2019 isolated primary CABG experience in the STS Adult Cardiac Surgery Database was analysed (241 902 patients; 1014 hospitals; 2718 surgeons). Generalized Estimating Equations were used to estimate coefficients between CABG institutional case volumes and outcomes. The observed-to-expected ratios based on STS risk models were used to assess risk-adjusted operative mortality (OM), mortality/major morbidity (MM) and deep sternal wound infections (DSWI) as a function of institutional case volumes. RESULTS: The mean (standard deviation) OM, MM and DSWI rates were 2.1% (2.7), 11.1% (9.2) and 0.6% (0.5), respectively. The mean (standard deviation) institutional case volumes per study period was 239 (192); 23% and 9% of institutions performed <100 and >500 cases/study period, respectively. There was a weak negative correlation between expected mortality (R2 -0.0014), OM (R2 -0.0272), MM (R2 -0.1213) and DSWI (R2 -0.003) and institutional case volumes. CONCLUSIONS: CABG outcomes generally improve with increasing institutional case volumes. Given the large number of CABG cases performed nationally, even the documented weak correlation has the potential to appreciably decrease OM, MM and DSWI if cases are performed at higher volume institutions. Studies focusing on additional hospital and surgeon factors are warranted to further define quality improvement opportunities.

Long-term Outcomes and Anticoagulation in Mitral Valve Surgery-A Report From The Society of Thoracic Surgeons Database.

BACKGROUND: Anticoagulation after bioprosthetic mitral valve (MV) replacement (BMVR) and repair (MVrep) is controversial. We explore outcomes among BMVR and MVrep patients in The Society of Thoracic Surgeons Adult Cardiac Surgery Database based on discharge anticoagulation status. METHODS: BMVR and MVrep patients aged ≥65 years in The Society of Thoracic Surgeons Adult Cardiac Surgery Database were linked to the Centers for Medicare and Medicaid Services claims database. Long-term mortality, ischemic stroke, bleeding, and a composite of the primary end points were compared as a function of anticoagulation. Hazard ratios (HRs) were calculated using multivariable Cox regression. RESULTS: A total of 26,199 BMVR and MVrep patients were linked to the Centers for Medicare and Medicaid Services database; of these, 44%, 4%, and 52% were discharged on warfarin, non-vitamin K-dependent anticoagulant (NOAC), and no anticoagulation (no-AC; reference), respectively. Warfarin was associated with increased bleeding in the overall study cohort (HR, 1.38; 95% CI 1.26-1.52) and in the BMVR (HR, 1.32; 95% CI, 1.13-1.55) and MVrep subcohorts (HR, 1.42; 95% CI, 1.26-1.60). Warfarin was associated with decreased mortality only among BMVR patients (HR, 0.87; 95% CI, 0.79-0.96). Stroke and the composite outcome did not differ across cohorts with warfarin. NOAC use was associated with increased mortality (HR, 1.33; 95% CI 1.11-1.59), bleeding (HR, 1.37; 95% CI, 1.07-1.74), and the composite outcome (HR, 1.26; 95% CI, 1.08-1.47). CONCLUSIONS: Anticoagulation was used in fewer than half of mitral valve operations. In MVrep patients, warfarin was associated with increased bleeding and was not protective against stroke or mortality. In BMVR patients, warfarin was associated with a modest survival benefit, increased bleeding, and equivalent stroke risk. NOAC was associated with increased adverse outcomes.

Operative Outcomes of Women Undergoing Coronary Artery Bypass Surgery in the US, 2011 to 2020.

Importance: It has been reported that women undergoing coronary artery bypass have higher mortality and morbidity compared with men but it is unclear if the difference has decreased over the last decade. Objective: To evaluate trends in outcomes of women undergoing coronary artery bypass in the US from 2011 to 2020. Design, Setting, and Participants: This retrospective cohort study at hospitals contributing to the Adult Cardiac Surgery Database of the Society of Thoracic Surgeons included 1 297 204 patients who underwent primary isolated coronary artery bypass from 2011 to 2020. Exposure: Coronary artery bypass. Main Outcomes and Measures: The primary outcome was operative mortality. The secondary outcome was the composite of operative mortality and morbidity (including operative mortality, stroke, kidney failure, reoperation, deep sternal wound infection, prolonged mechanical ventilation, and prolonged hospital stay). The attributable risk (the association of female sex with coronary artery bypass grafting outcomes) for the primary and secondary outcomes was calculated. Results: Between 2011 and 2020, 1 297 204 patients underwent primary isolated coronary artery bypass grafting with a mean age of 66.0 years, 317 716 of which were women (24.5%). Women had a higher unadjusted operative mortality (2.8%; 95% CI, 2.8-2.9 vs 1.7%; 95% CI, 1.7-1.7; P < .001) and overall unadjusted incidence of the composite of operative mortality and morbidity compared with men (22.9%; 95% CI, 22.7-23.0 vs 16.7%; 95% CI, 16.6-16.8; P < .001). The attributable risk of female sex for operative mortality varied from 1.28 in 2011 to 1.41 in 2020, with no significant change over the study period (P for trend = 0.38). The attributable risk for the composite of operative mortality and morbidity was 1.08 in both 2011 and 2020 with no significant change over the study period (P for trend = 0.71). Conclusions and Relevance: Women remain at significantly higher risk for adverse outcomes following coronary artery bypass grafting and no significant improvement has been seen over the course of the last decade. Further investigation into the determinants of operative outcomes in women is urgently needed.

Risk of Surgical Mitral Valve Repair for Primary Mitral Regurgitation.

BACKGROUND: Risk estimation for surgical intervention is an essential component of heart team shared decision-making. However, current mitral valve (MV) surgery risk models used in practice lack etiologic or procedural specificity. OBJECTIVES: The purpose of this study was to establish a comprehensive method for assessment of operative risk of MV repair of primary mitral regurgitation (MR). METHODS: A novel etiology and procedure-specific algorithm identified 53,462 consecutive (July 2014 to June 2020) intention-to-treat MV repair patients with primary MR from The Society of Thoracic Surgeons Adult Cardiac Surgery Database. Risk models were fit for 30-day operative mortality, mortality and/or major morbidity, and conversion-to-replacement (CONV). As-treated mortality and morbidity models were derived separately. RESULTS: Event rates for mortality (n = 619; 1.16%), mortality plus morbidity (n = 4,746; 8.88%), and CONV (n = 3,399; 6.36%) were low. Mortality was higher in CONV patients vs repair (3.18% vs 1.02%). All event rates were lower with increasing program volumes. The mortality risk model had excellent discrimination (AUC: 0.807) and calibration and confirmed very low mortality risk for isolated MV repair for primary MR, with mean mortality risk of 1.16% and median of 0.55% (IQR: 0.30%-1.17%) with 90th and 95th percentiles 2.48% and 3.99%, respectively. The mortality risk was <0.5% in patients <65 years of age, with 97% of the total population across age groups having a risk of <3%. Only 1 in 4 patients age 75 or older had >3% estimated risk of mortality. CONCLUSIONS: This etiologic and procedure-specific risk model establishes that the contemporary mortality risk of MV repair for primary MR is <1% for the vast majority of patients.

Risk of Surgical Mitral Valve Repair for Primary Mitral Regurgitation.

BACKGROUND: Risk estimation for surgical intervention is an essential component of heart team shared decision-making. However, current mitral valve (MV) surgery risk models used in practice lack etiologic or procedural specificity. The purpose of this study was to establish a comprehensive method for assessment of operative risk of MV repair of primary mitral regurgitation (MR). METHODS: A novel etiology and procedure-specific algorithm identified 53,462 consecutive (July 2014 to June 2020) intention-to-treat MV repair patients with primary MR from The Society of Thoracic Surgeons Adult Cardiac Surgery Database. Risk models were fit for 30-day operative mortality, mortality and/or major morbidity, and conversion-to-replacement (CONV). As-treated mortality and morbidity models were derived separately. RESULTS: Event rates for mortality (n = 619; 1.16%), mortality plus morbidity (n = 4746; 8.88%), and CONV (n = 3399; 6.36%) were low. Mortality was higher in CONV patients vs repair (3.18% vs 1.02%). All event rates were lower with increasing program volumes. The mortality risk model had excellent discrimination (AUC: 0.807) and calibration and confirmed very low mortality risk for isolated MV repair for primary MR, with mean mortality risk of 1.16% and median of 0.55% (interquartile range: 0.30%-1.17%) with 90th and 95th percentiles 2.48% and 3.99%, respectively. The mortality risk was <0.5% in patients <65 years of age, with 97% of the total population across age groups having a risk of <3%. Only 1 in 4 patients age 75 or older had >3% estimated risk of mortality. CONCLUSIONS: This etiologic and procedure-specific risk model establishes that the contemporary mortality risk of MV repair for primary MR is <1% for the vast majority of patients.

Development of a Novel Society of Thoracic Surgeons Adult Congenital Mortality Risk Model.

BACKGROUND: Operative mortality risk models for adults with congenital heart disease (ACHD) undergoing cardiac operations are essential, given the growing population of these patients, yet they are currently unavailable. Existing adult Society of Thoracic Surgeons (STS) models exclude congenital procedures, whereas existing congenital models exclude operations for acquired disease. We aimed to develop an STS mortality risk model for ACHD patients undergoing cardiac operations. METHODS: Leveraging a comprehensive list of diagnostic and procedure codes, ACHD patients who underwent cardiac operations were identified from the STS Adult Cardiac Surgery Database (versions: v2.73, v2.81, and v2.9) between 2011 and 2019. The model was developed and validated in the ACHD population using a 60/40 development/validation split. Univariate analyses and clinical expertise informed the addition of ACHD-relevant procedure and diagnosis variables to existing STS adult risk model variables. Model performance was assessed overall and in 38 subgroups based on patient demographics, procedures, and diagnoses. RESULTS: Forty-seven procedure and diagnosis variables relevant to ACHD were added to existing STS adult risk model variables. The derived ACHD model for operative mortality was well calibrated within demographic, procedural, and diagnosis subgroups and the overall ACHD population, and discrimination in the validation cohort was excellent (C statistic, 0.815) compared with the model using only existing STS adult risk model variables (C statistic, 0.79; P < .0001). CONCLUSIONS: A novel, high-performing STS ACHD mortality risk model has been developed on the basis of contemporary patient data. The ACHD risk model represents an important expansion of the STS portfolio. Implementation with an online risk calculator is planned.

Perioperative Anemia and Transfusions and Late Mortality in Coronary Artery Bypass Patients.

BACKGROUND: Perioperative anemia and transfusions are associated with adverse operative outcomes after coronary artery bypass graft surgery (CABG). Their individual association with long-term outcomes is unclear. METHODS: Patients aged 65 years and older who had undergone CABG and were in The Society of Thoracic Surgeons (STS) Adult Cardiac Surgery Database (n = 504,596) from 2011 to 2018 were linked to Centers for Medicare and Medicaid Service data to assess long-term survival. The association of intraoperative anemia defined by intraoperative nadir hematocrit (nHct) and red blood cell (RBC) transfusions, and their interactions, on long-term mortality were assessed with Kaplan-Meier estimates and multivariable Cox regression. Restricted cubic splines were used to explore the association between nHct as a continuous variable and long-term mortality. RESULTS: 258,398 on-pump CABG STS Adult Cardiac Surgery Database patients surviving the perioperative period were linked to Centers for Medicare and Medicaid Service claims files. Per World Health Organization criteria, 41% had preoperative anemia. Mean intraoperative nHct was 24%; RBC transfusion rate was 43.7%. Univariable analysis associated both RBC transfusion and lower nHct with worse survival. Lower nHct was only marginally associated with risk-adjusted mortality: adjusted hazard ratio (AHR) 1.04 (95% CI, 1.01-1.06) and 1.07 (95% CI, 1.00-1.14) at nHct 20% and at nHct 14%, respectively. RBC transfusion was associated with significantly higher adjusted mortality irrespective of timing of transfusion: AHR intraoperative 1.21 (95% CI, 1.18-1.27); AHR postoperative 1.26 (95% CI, 1.22-1.30); AHR both 1.46 (95% CI, 1.40-1.52) and across all levels of nHct. RBC transfusion was not associated with improved survival at any level of nHct. CONCLUSIONS: Among Medicare CABG patients, RBC transfusions were associated with increased risk-adjusted late mortality across all levels of nHct whereas intraoperative anemia was only marginally so. Tolerance of lower intraoperative nHct than currently accepted may be preferable to transfusions.

Incidence and Impact of a Single-Unit Red Blood Cell Transfusion: Analysis of The Society of Thoracic Surgeons Database 2010-2019.

BACKGROUND: As the adverse effects of blood transfusions are better understood, recommendations support single-unit red blood cell (RBC) transfusions (SRBCT). However, an isolated SRBCT across the entire index admission suggests even the single unit may be avoidable. We sought to identify the characteristics of cardiac surgery patients receiving an isolated SRBCT and analyze the impact on outcomes. METHODS: The Society of Thoracic Surgeons Adult Cardiac Surgery Database was queried for the period between January 1, 2010, and December 31, 2019. Patients aged >18 years undergoing isolated coronary artery bypass grafting or isolated aortic valve replacement were included. A total of 2,151,430 encounters were analyzed. RESULTS: Of the 847,442 patients (39.3%) receiving any RBC transfusion during their index admission, 206,555 (24.4%) received only 1 unit. Propensity-matching analysis determined SRBCT patients were significantly older (67.26 vs 64.02 years; odds ratio [OR], 1.02; P < .001), female (39.1% vs 17.8%; OR, 1.57; P < .001), non-White (18.2% vs 13.1%; OR, 0.81; P < .001), and had a smaller body surface area (1.94 vs 2.07 m2; OR, 0.20; P < .001). They also had higher mortality (1.4% vs 1.0%, P < .001), stroke (1.7% vs 1.2%, P < .001), prolonged ventilation (6.4% vs 3.4%, P < .001), renal failure (1.8% vs 0.9%, P < .001), and reoperations (1.3% vs. 0.5%, P < .001) than patients who received 0 RBCs. CONCLUSIONS: SRBCT is a common occurrence in adult cardiac surgery. This low-volume transfusion is strongly associated with higher morbidity, even after controlling for preoperative risk factors.