Surgeons Adult Cardiac Surgery Database Research Articles

Development of a Novel Society of Thoracic Surgeons Aortic Surgery Mortality and Morbidity Risk Model

The Society of Thoracic Surgeons Adult Cardiac Surgery Database (STS-ACSD) was expanded in 2017 to include more granular detail on thoracic aortic surgeries. We describe the first validated risk model in thoracic aortic surgery from the STS-ACSD. The study population consisted of patients undergoing non-emergent isolated ascending aortic aneurysm repair using open or clamped distal anastomoses, including those requiring aortic root or valve replacement. Model outcomes included operative mortality, 30-day major morbidity (cardiac reoperation, deep sternal wound infection, stroke, prolonged ventilation, renal failure) and a composite of both. To select the predictors, univariate associations and clinical face validity of models were examined. Models were evaluated by their ability to distinguish between patients with and without specific outcomes (discrimination) and their predictive accuracy (calibration). Between 2017 and 2021, 24,051 eligible patients underwent ascending aortic aneurysm surgery at 905 hospitals. Procedures included 8,913 aortic root replacements, 2,135 valve-sparing root replacements, 7,545 ascending aortic replacements with AVR, and 5,458 ascending aortic replacements. Circulatory arrest was performed in 7,316 (30.4%) of cases. Operative mortality was 1.9%, and 12.2% of patients experienced major morbidity including 2.4% incidence of stroke. The adjusted C-statistics for the model were 0.74, 0.67 and 0.67 for mortality, morbidity and the composite, respectively. Previous stroke and circulatory arrest were associated with new stroke. Genetic aortopathy was associated with less mortality. A new STS-ACSD risk model to predict mortality and morbidity after ascending aneurysm surgery has been developed, and predictors of better and worse outcomes have been identified.

Factors Associated with Permanent Pacemaker Placement After Tricuspid Valve Operations

Conduction abnormalities requiring permanent pacemaker (PPM) implantation are common after tricuspid valve operations, although the incidence is variable. This study investigated contemporary rates of and risk factors for a PPM after tricuspid operations. The Society of Thoracic Surgeons Adult Cardiac Surgery Database was used to identify patients with tricuspid repair or replacement from 2011 to 2020. Factors independently associated with the risk of a postoperative PPM during the index hospital admission were examined using multivariable logistic regression with a complete case approach. Annualized hospital and surgeon volumes were calculated. We identified 71,937 patients undergoing tricuspid operations. Median patient age was 66 years (interquartile range, 53-74 years), 56% (n= 40,590) were women, and the median ejection fraction was 0.56 (interquartile range, 0.48-0.60). Tricuspid operations were concomitant in 87% (n= 62,457), elective in 62% (n= 44,393), and included repair in 86% (n= 61,720). Overall postoperative incidence of a PPM was 15% (n= 10,857); 13% (n= 8304) after repair and 25% (n= 2553) after replacement; and 4% (n= 174) for isolated tricuspid repair and 24% (n= 1248) for isolated tricuspid replacement. Multivariable analysis showed baseline characteristics, endocarditis, concomitant operations, longer cardiopulmonary bypass time, tricuspid replacement, and lower hospital and surgeon tricuspid operative volumes were independently associated with greater risk for a PPM. After adjustment, tricuspid replacement had 3.2-times greater PPM risk compared with tricuspid repair. Nationally, 15% of patients undergoing tricuspid operations required postoperative PPM implantation. PPM risk was increased with concomitant valve operations, tricuspid replacement, longer cardiopulmonary bypass time, and operations performed by less experienced surgeons and centers. Innovation is needed to decrease this significant morbidity.

Impact of Hospital Transfers on Cardiac Surgery Outcomes: A Society of Thoracic Surgeons Adult Cardiac Surgery Database Analysis

BackgroundTransfers for cardiac surgery are not well studied. We sought to understand the risk profile of transferred patients and determine whether transfer rates vary by cardiac surgery and whether outcomes of transferred patients vary with type of referral hospital/surgery. MethodsPatients undergoing cardiac surgery with operative risk models were identified from The Society of Thoracic Surgeons database between July 1, 2014, and December 31, 2022. Patients were stratified as no transfer, transferred from hospital with cardiac surgery, and transferred from hospital without cardiac surgery. Risk associated with transfer compared with no transfer was derived by using multivariable logistic regression for operative mortality and select perioperative outcomes. ResultsIncluded were 1,828,787 patients at 1145 hospitals, with 1,452,491 no-transfer patients (79.4%), 28,862 transfers (1.6%) from hospitals with cardiac surgery, and 347,434 transfers (19.0%) from hospitals without cardiac surgery. Most transferred patients underwent coronary artery bypass grafting (83.6%); however, transfers from hospitals with cardiac surgery were most common for mitral valve replacement (17.9%). Transferred patients had increased comorbid diseases and urgent/emergent procedures. In multivariable analysis, transfers from hospitals with/without cardiac surgery were not associated with differential risk of adverse outcomes by procedure type. Patients transferred from hospitals with cardiac surgery undergoing mitral and aortic valve replacement and coronary artery bypass grafting had significantly lower adjusted mortality risk compared with nontransferred patients, whereas composite morbidity/mortality was higher in mitral valve repair. ConclusionsPatients transferred for cardiac surgery are generally higher risk; yet, outcomes at transfer to hospitals are as expected or better. However, further research is necessary to examine patients who are transferred but do not undergo surgery.

Safety and Outcomes of Reoperative Robotic Tricuspid Valve Surgery.

Reoperative surgery for isolated tricuspid valve (TV) pathology has been associated with high morbidity and mortality rates; however, the current guidelines recommend intervention for severe, symptomatic TV regurgitation or mild to moderate symptoms with progressive right ventricular dysfunction. There are minimal data regarding reoperative intervention for TV disease. Similarly, there are no large series describing robot-assisted reoperative TV surgery. Institutional Society of Thoracic Surgeons Adult Cardiac Surgery Database data were used to identify patients with previous cardiac surgery undergoing robot-assisted TV surgery from 2017 to 2022 from 2 tertiary referral hospitals. Patient demographics, preoperative characteristics, disease progression, operative details, and outcomes were analyzed. The primary outcome was 30-day mortality. Secondary outcomes were 30-day readmission, length of stay, and adverse events. Descriptive and summative statistics were used to describe clinical data and examine differences in outcomes of patients with primary versus secondary etiology using bivariate analyses. Twenty-four patients were divided into 2 arms, primary TV pathology and secondary dysfunction due to comorbid cardiac conditions. The overall mortality was 8.3%. Major complications, including respiratory failure, renal failure, and reoperation were 12.5%, 8.3%, and 8.3%, respectively. No permanent pacemakers were required, and the 30-day readmission rate was 4.5%. Reoperative robotic TV surgery is a safe and viable alternative to traditional sternotomy for both primary and secondary TV pathology. TV repair and replacement are possible using the minimally invasive technique. The morbidity and mortality rates are acceptable when compared with traditional approaches with decreased need for pacemaker placement in the minimally invasive approach.

Sex, Atrial Fibrillation, and Long-Term Mortality After Cardiac Surgery

There are limited data on the association of sex with the incidence of postoperative atrial fibrillation (poAF) and subsequent long-term mortality after cardiac surgery. To evaluate whether the incidence of poAF and associated long-term mortality after cardiac surgery differ by sex. This retrospective cohort study was conducted at 2 tertiary care centers in Massachusetts from January 1, 2002, until October 1, 2016, with follow-up until December 1, 2022. Adult (aged >20 years) women and men undergoing coronary artery bypass graft surgery, aortic valve surgery, mitral valve surgery, and combined procedures with cardiopulmonary bypass were examined using medical records. Patients who had data on poAF were included in data analyses. Sex and poAF. Primary outcomes were the incidence of poAF and all-cause mortality. poAF was defined as any atrial fibrillation detected on electrocardiogram (EKG) during the index hospitalization in patients presenting for surgery in normal sinus rhythm. Data on poAF were obtained from EKG reports and supplemented by information from the Society of Thoracic Surgeons Adult Cardiac Surgery Database. All-cause mortality was assessed via hospital records. The hypotheses were formulated prior to data analysis. Among 21 568 patients with poAF data (mean [SD] age, 66.5 [12.4] years), 2694 of 6601 women (40.8%) and 5805 of 14 967 men (38.8%) developed poAF. In a multivariable logistic regression model, women had lower risk of poAF (odds ratio [OR], 0.85; 95% CI, 0.79-0.91; P < .001). During the follow-up study period, 1294 women (50.4%) and 2376 men (48.9%) in the poAF group as well as 1273 women (49.6%) and 2484 men (51.1%) in the non-poAF group died. Cox proportional hazards analysis found that the association between poAF and mortality was significantly moderated (ie, effect modified) by sex. Compared with same-sex individuals without poAF, men with poAF had a 17% higher mortality hazard (hazard ratio [HR], 1.17; 95% CI, 1.11-1.25; P < .001), and women with poAF had a 31% higher mortality hazard (HR, 1.31; 95% CI, 1.21-1.42; P < .001). In this retrospective cohort study of 21 568 patients who underwent cardiac surgery, women were less likely to develop poAF than men when controlling for other relevant characteristics; however, women who did develop poAF had a higher risk of long-term mortality than men who developed poAF. This observed elevated risk calls for a tailored approach to perioperative care in women undergoing cardiac surgery.

Hematocrit and Renal Failure in Aortic Arch Surgery: A Society of Thoracic Surgeons Database Study

BackgroundThis study examined the association between cardiopulmonary bypass (CPB) hematocrit and postoperative acute renal failure (ARF) in patients undergoing aortic arch surgery with hypothermic circulatory arrest. MethodsThe Society of Thoracic Surgeons Adult Cardiac Surgery Database was queried from 2011 to 2019 for patients undergoing aortic arch surgery with hypothermic circulatory arrest. A multivariable logistic regression model estimated the adjusted odds of postoperative ARF on the basis of CPB hematocrit. Effects were stratified by preoperative kidney function and the duration of hypothermic circulatory arrest by using interaction terms. The study also investigated the association between postoperative ARF and major postoperative outcomes by using multivariable regression models. ResultsOn adjusted analysis, higher CPB hematocrit (>20%-25%, >25%-30%, >30%) was associated with lower odds of ARF as compared with lower CPB hematocrit (≤20%) (>20-25%, aOR, 0.78; 95% CI, 0.65-0.93; P = .006; >25%-30%, aOR, 0.65; 95% CI, 0.50-0.84; P = .0007; >30%, aOR, 0.45; 95% CI, 0.28-0.72; P = .0008). The predicted probability of postoperative ARF by CPB hematocrit was higher in patients with lower preoperative renal function (estimated glomerular filtration rate, <60 mL/min/1.73 m2) (interaction P = .03). The association between hematocrit and postoperative ARF was not significantly modified by hypothermic circulatory arrest time (interaction P = .74). All postoperative outcomes were significantly worse in patients with postoperative ARF (all P < .0001). ConclusionsAmong patients undergoing aortic arch surgery, a higher CPB hematocrit level is associated with reduced likelihood of postoperative ARF. Preoperative renal function, but not hypothermic circulatory arrest duration, significantly modified this association. The maintenance of higher CPB hematocrit may reduce the incidence of postoperative ARF, especially for patients with poor preoperative renal function.

Descending Thoracic and Thoracoabdominal Aortic Aneurysm Repairs: The Society of Thoracic Surgeons Adult Cardiac Surgery Database Analysis

BackgroundContemporary national outcomes of open and endovascular aortic repair for descending thoracic aortic aneurysms (DTAAs) and thoracoabdominal aortic aneurysms (TAAAs) are unclear. This study evaluated this issue by using The Society of Thoracic Surgeons (STS) Adult Cardiac Surgery Database (ACSD). MethodsFrom July 1, 2017 to June 30, 2022, study investigators identified 3522 adults who underwent planned DTAA repair (open, 328; endovascular, 1895) or TAAA repair (open, 870; endovascular, 429), after excluding ascending aorta or aortic arch aneurysms (zone 0, 1, or 2), interventions with a proximal extent in zone 0 or zone 1, juxtarenal or infrarenal aortic interventions, hybrid procedures, aortic trauma, and aortic infection. ResultsMost DTAA interventions (85.2%) were endovascular repairs, whereas most TAAA interventions were open repairs (66.9%). For DTAA interventions, the operative mortality, permanent stroke rate, and rate of spinal cord injury were 4.2%, 3.8%, and 2.4% for endovascular repairs and 9.2%, 8.5%, and 4.6% for open repairs, respectively (all P < .05). For TAAA interventions, the operative mortality, permanent stroke rate, and rate of spinal cord injury were 6.5%, 2.1%, and 3.0% for endovascular repairs and 11.7%, 6.0%, and 12.2% for open repairs, respectively (all P < .05). Increasing annual open TAAA repair volume was associated with lower odds of experiencing the composite of operative mortality, permanent stroke, or spinal cord injury. ConclusionsOn the basis of STS ACSD data, endovascular repair was the predominant approach for treating DTAA, whereas most patients undergoing TAAA interventions had an open surgical repair. Outcome differences between open and endovascular approaches may be related to patient selection. Increasing center experience with open TAAA repair is associated with improved outcomes.

Risk of Transfusion in Isolated Coronary Artery Bypass Graft: Models Developed From The Society of Thoracic Surgeons Database

BackgroundPerioperative blood transfusion is associated with adverse outcomes and higher costs after coronary artery bypass graft (CABG) surgery. We developed risk assessments for patients’ probability of perioperative transfusion and the expected transfusion volume to improve clinical management and resource use. MethodsAmong 1,266,545 consecutive (2008-2016) isolated CABG operations in The Society of Thoracic Surgeons Adult Cardiac Surgery Database, 657,821 (51.9%) received perioperative transfusions of red blood cells (RBC), fresh frozen plasma (FFP), cryoprecipitate, and/or platelets. We developed “full” models to predict perioperative transfusion of any blood product, and of RBC, FFP, or platelets. Using least absolute shrinkage and selection operator model selection, we built a rapid risk score based on 5 variables (age, body surface area, sex, preoperative hematocrit, and use of intra-aortic balloon pump). ResultsC statistics for the full model were 0.785, 0.815, 0.707, and 0.699 for any blood product, RBC, FFP, and platelets, respectively. C statistics for rapid risk assessments were 0.752, 0.785, 0.670, and 0.661 for any blood product, RBC, FFP, and platelets, respectively. The observed vs expected risk plots showed strong calibration for full models and risk assessment tools; absolute differences between observed and expected risks of transfusion were <10.8% in each percentile of expected risk. Risk assessment–predicted probabilities of transfusion were strongly and nonlinearly associated (P < .0001) with total units transfused. ConclusionsThese robust and well-calibrated risk assessment tools for perioperative transfusion in CABG can inform surgeons regarding patients’ risks and the number of RBC, FFP, and platelets units they can expect to need. This can aid in optimizing outcomes and increasing efficient use of blood products.

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

BackgroundThe 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. MethodsPatients 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. ResultsThe 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). ConclusionsExtubation 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.

Atrial Fibrillation After Coronary Artery Bypass Grafting and Its Relationship with Hospital Complications in São Paulo State.

Atrial fibrillation is the main complication in the postoperative period of cardiovascular surgery. Its genesis is multifactorial, so its rapid identification to mitigate the associated risks is essential. To evaluate the incidence of atrial fibrillation in patients undergoing coronary artery bypass grafting (CABG) and its relationship with other complications in our setting. This is a multicenter, observational study involving patients undergoing isolated CABG between 2017 and 2019 with data from the Registro Paulista de Cirurgia Cardiovascular (or REPLICCAR II). Variables were prospectively collected in REDCap following the definitions given by version 2.73 of the Society of Thoracic Surgeons Adult Cardiac Surgery Database. Data were collected with prior authorization from the local ethics committee and analyses performed in R software. A total of 3,803 patients were included, of these 605 had postoperative atrial fibrillation (POAF). In order to adjust the groups, propensity score matching was used. Such analyses resulted in 605 patients in each group (without POAF vs. with POAF). Among patients with POAF, the mean age was 67.56 years, with a prevalence of males (73.6%, 445 patients). Patients belonging to the group with POAF had a mortality rate of 9.26% (P=0.007), longer ventilation time (P<0.001), pneumonia (P<0.001), and sepsis (P<0.001). In multiple analysis, acute renal dysfunction (P=0.032) and longer intensive care unit stay (P<0,001) were associated with the presence of POAF. POAF in CABG is associated with longer intensive care unit and hospital stay, as well as renal dysfunction, pneumonia, and in-hospital mortality.

Outcomes of Isolated Tricuspid Valve Surgery: A Society of Thoracic Surgeons Analysis and Risk Model

BackgroundTo provide patients and surgeons with clinically relevant information, The Society of Thoracic Surgeons (STS) Adult Cardiac Surgery Database was queried to develop a risk model for isolated tricuspid valve (TV) operations. MethodsAll patients in the STS Adult Cardiac Surgery Database who had undergone isolated TV repair or replacement (N = 13,587; age 48.3 ± 18.4 years) were identified (July 2017 to June 2023). Multivariable logistic regression accounting for TV replacement vs repair was used to model 8 operative outcomes: mortality, morbidity or mortality or both, stroke, renal failure, reoperation, prolonged ventilation, short hospital stay, and prolonged hospital stay. Model discrimination (C-statistic) and calibration were assessed using 9-fold cross-validation. ResultsThe isolated TV study population included 41.1% repairs (N = 5,583; age 52.6 ± 18.1 years) and 58.9% replacements (N = 8,004; age 45.3 ± 18.0 years). The overall predicted risk of operative mortality was 5.6%, and it was similar in TV repairs and replacements (5.5% and 5.7%, respectively), as was the predicted risk of composite morbidity and mortality (28.2% and 26.8%). TV replacements were generally performed in younger patients with a higher endocarditis prevalence than TV repairs (45.7% vs 21.1%). The model yielded a C-statistic of 0.81 for mortality and 0.76 for the composite of morbidity and mortality, with excellent observed-to-expected calibration that was comparable in all subcohorts and predicted risk decile groups. ConclusionsAn STS risk model has been developed for isolated TV surgery. The current mortality of isolated TV operations is lower than previously observed. This risk prediction model and these contemporary outcomes provide a new benchmark for current and future isolated TV interventions.

Cardiac Surgery After Transcatheter Aortic Valve Replacement: Trends and Outcomes

BackgroundReports 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. MethodsThe 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. ResultsOf 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. ConclusionsThe 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.

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

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

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

BackgroundAlthough 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. MethodsAll 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. ResultsA 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. ConclusionsMultiarterial 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.

The Society of Thoracic Surgeons Adult Cardiac Surgery Database: Intraoperative Echocardiography Reporting

To identify trends in the reporting of intraoperative transesophageal echocardiographic (TEE) data in the Society of Thoracic Surgeons (STS) Adult Cardiac Surgery Database (ACSD) and the Adult Cardiac Anesthesiology (ACA) module by period, practice type, and geographic distribution, and to elucidate ongoing areas for practice improvement. A retrospective study. STS ACSD. Procedures reported in the STS ACSD between July 2017 and December 2021 in participating programs in the United States. None MEASUREMENTS AND MAIN RESULTS: Intraoperative TEE is reported for 73% of all procedures in ACSD. Although the intraoperative TEE data reporting rate increased from 2017 to 2021 for isolated coronary artery bypass graft surgery, it remained low at 62.2%. The reporting of relevant echocardiographic variables across a wide range of procedures has steadily increased over the study period but also remained low. The reporting in the ACA module is high for most variables and across all anesthesia care models; however, the overall contribution of the ACA module to the ACSD remains low. This progress report suggests a continued need to raise awareness regarding current practices of reporting intraoperative TEE in the ACSD and the ACA, and highlights opportunities for improving reporting and data abstraction.

Renal recovery in cardiac surgery patients requiring postoperative renal-replacement therapy

ObjectiveRenal failure after cardiac surgery is associated with increased morbidity and mortality. There is a lack of data examining the rate of renal recovery after patients have started dialysis following cardiac surgery. We aimed to determine the frequency of and time to renal recovery of patients requiring dialysis after cardiac surgery. MethodsAll patients who developed new-onset renal failure requiring dialysis following cardiac surgery at our institution from 2011 to 2022 were included. Renal recovery, time to renal recovery, and mortality at 1 year were merged with patients’ Society of Thoracic Surgeons Adult Cardiac Surgery Database files. Kaplan–Meier analysis was used to predict time to renal recovery; we censored patients who died or were lost to follow up. Cox regression was used for risk-adjustment. ResultsA total of 312 patients were included in the final analysis. Mortality during index hospital admission was 33% (n = 105), and mortality at 1 year was 45% (n = 141). Of those surviving at 1 year, 69% (n = 118) remained renally recovered. Median renal recovery time was 56 (37-74) days. Accounting for mortality as a competing risk, 51% of patients were predicted to achieve renal recovery. Increasing age (hazard ratio, 0.98; 0.514-0.94, P < .026) and increasing total packed red blood cells (hazard ratio, 0.0958; 0.937-0.987, P < .001) received were found to be significant negative predictors of renal recovery in the Fine-Gray model for subhazard distribution. ConclusionsMore than two-thirds of patients with renal failure who survived the perioperative period had renal recovery within 1 year after surgery. Recovery was driven primarily by postoperative complications rather than comorbidities and intraoperative factors, suggesting renal failure in the postoperative cardiac surgery patient surviving to discharge is unlikely to be permanent.

The Society of Thoracic Surgeons Adult Cardiac Surgery Database: 2023 Update on Procedure Data and Research

The Society of Thoracic Surgeons (STS) Adult Cardiac Surgery Database is one of the largest and most comprehensive contemporary clinical databases in use. It now contains >9 million procedures from 1010 participants and 3651 active surgeons. Using audited data collection, it has provided the foundation for multiple risk models, performance metrics, health policy decisions, and a trove of research studies to improve the care of patients in need of cardiac surgical procedures. This annual report provides an update on the current status of the database and summarizes the development of new risk models and the STS Online Risk Calculator. Further, it provides insights into current practice patterns, such as the change in the demographics among patients undergoing aortic valve replacement, the use of minimally invasive techniques for valve and bypass surgery, or the adoption of surgical ablation and left atrial appendage ligation among patients with atrial fibrillation. Lastly, an overview of the research conducted using the STS Adult Cardiac Surgery Database and future directions for the database are provided.

Interpretable Machine Learning-Based Predictive Modeling of Patient Outcomes Following Cardiac Surgery

ObjectiveThe clinical applicability of machine learning predictions of patient outcomes following cardiac surgery remains unclear. We applied machine learning to predict patient outcomes associated with high morbidity and mortality after cardiac surgery and identified the importance of variables to the derived model’s performance. MethodsWe applied machine learning to the Society of Thoracic Surgeons Adult Cardiac Surgery Database to predict post-operative hemorrhage requiring re-operation, venous thromboembolism and stroke. We used permutation feature importance to identify variables important to model performance and a misclassification analysis to study the limitations of the model. ResultsThe study dataset included 662,772 subjects who had cardiac surgery between 2015 and 2017 and 240 variables. Hemorrhage requiring re-operation, venous thromboembolism and stroke occurred in 2.9%, 1.2% and 2.0% of subjects respectively. The model performed remarkably well at predicting all three complications (AUC 0.92-0.97). Pre- and intra-operative variables were not important to model performance. Instead, performance for the prediction of all three outcomes was driven primarily by several post-operative variables, including known risk factors for the complications such as mechanical ventilation and new-onset of post-operative arrhythmias. Many of the post-operative variables important to model performance also increased the risk of subject misclassification, indicating internal validity. ConclusionsA machine learning model accurately and reliably predicts patient outcomes following cardiac surgery. Post-operative, as opposed to pre- or intra-operative variables, are important to model performance. Interventions targeting this period including minimizing the duration of mechanical ventilation and early treatment of new-onset post-operative arrhythmias may help lower the risk of these complications.

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

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. The 2018-2019 isolated primary CABG experience in the STS Adult Cardiac Surgery Database was analysed (241902 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. 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. 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.

Interhospital variability in failure to rescue rates following aortic valve surgery

ObjectiveThis study evaluated interhospital variability and determinants of failure-to-rescue for patients undergoing surgical aortic valve replacement. MethodsAn observational study was conducted among 28,842 patients undergoing aortic valve replacement with or without coronary artery bypass grafting between July 2011 and June 2017 across 90 hospitals participating in the Society of Thoracic Surgeons Adult Cardiac Surgery Database. Postoperative complications were defined as major (stroke, renal failure, reoperation, prolonged ventilation, sternal infection) and overall (major plus 14 other morbidities). Hospital terciles of observed to expected (O/E) mortality were compared on crude rates of major and overall complications, operative mortality, and failure to rescue (among major and overall complications). The correlation between hospital observed and expected failure-to-rescue rates was assessed. ResultsMedian Society of Thoracic Surgeons Adult Cardiac Surgery Database predicted mortality risk was similar across hospital O:E mortality terciles (P = .10). As expected, mortality rates significantly increased across terciles (low O/E tercile: 1.6%, high O/E tercile: 4.7%; P < .001). Failure-to-rescue rates increased substantially across hospital mortality terciles among patients with major (low tercile, 8.8% and high tercile, 20.8%) and overall (low tercile, 3.0% and high tercile, 8.9%) complications. Hospital-level expected failure to rescue had a higher correlation with observed complications for overall complications (R2 = 0.71) compared with Society of Thoracic Surgeons major complications (R2 = 0.24). ConclusionsConsiderable interhospital variation exists in failure-to-rescue rates following aortic valve replacement. Hospitals in the low O/E mortality tercile experience failure to rescue nearly one-third less than those in the high O/E mortality tercile. Efforts to advance quality will benefit from identifying and disseminating optimal rescue strategies in this patient population.