Penetration, Completeness, and Representativeness of The Society of Thoracic Surgeons Adult Cardiac Surgery Database

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.

The Society of Thoracic Surgeons 2021 Adult Cardiac Surgery Risk Models for Multiple Valve Operations

BACKGROUND

The Society of Thoracic Surgeons (STS) Quality Measurement Task Force has developed risk models and composite performance measures for isolated coronary artery bypass grafting (CABG), isolated aortic valve replacement (AVR), isolated mitral valve replacement or repair (MVRR), AVR+CABG, and MVRR+CABG. To further enhance its portfolio of risk-adjusted performance metrics, STS has developed new risk models for multiple valve operations ± CABG procedures.

METHODS

Using July 2011 to June 2019 STS Adult Cardiac Surgery Database data, risk models for AVR+MVRR (n = 31,968) and AVR+MVRR+CABG (n = 12,650) were developed with the following endpoints: Operative Mortality, major morbidity (any 1 or more of the following: cardiac reoperation, deep sternal wound infection/mediastinitis, stroke, prolonged ventilation, and renal failure), and combined mortality and/or major morbidity. Data were divided into development (July 2011 to June 2017; n = 35,109) and validation (July 2017 to June 2019; n = 9509) samples. Predictors were selected by assessing model performance and clinical face validity of full and progressively more parsimonious models. Performance of the resulting models was evaluated by assessing discrimination and calibration.

RESULTS

C-statistics for the overall population of multiple valve ± CABG procedures were 0.7086, 0.6734, and 0.6840 for mortality, morbidity, and combined mortality and/or morbidity in the development sample, and 0.6953, 0.6561, and 0.6634 for the same outcomes, respectively, in the validation sample.

CONCLUSIONS

New STS Adult Cardiac Surgery Database risk models have been developed for multiple valve ± CABG operations, and these models will be used in subsequent STS performance metrics.

AORTIC PROSTHETIC VALVE ENDOCARDITIS: ANALYSIS OF THE SOCIETY OF THORACIC SURGEONS DATABASE

BACKGROUND

We sought to characterize the current U.S. experience of aortic prosthetic valve endocarditis (PVE) compared to native valve endocarditis (NVE).

METHODS

The Society of Thoracic Surgeons Database was queried for entries of active aortic infective endocarditis (IE). Two analyses were performed: 1) Trends of surgical volume and operative mortality (2011 to 2019) and 2) Descriptive and risk-adjusted comparisons between PVE and NVE (2014 to 2019), using multivariable logistic regression.

RESULTS

From 2011 to 2019, there was a yearly increase in the proportion of PVE (20.9% to 25.9%; p<0.001) with a concurrent decrease in operative mortality (PVE=22.5% to 10.4%; p<0.001; NVE=10.9% to 8.5%; p<0.001). From 2014 to 2019, active aortic IE was identified in 9,768 patients (NVE=6,842; PVE=2,926). Aortic root abscess (50.1% versus 25.2%; p<0.001), aortic root replacement (50.1% versus 12.8%; p<0.001), homograft implantation (27.2% versus 4.1%; p<0.001), and operative mortality (12.2% versus 6.4%; p<0.001) were higher in PVE. Following risk-adjustment, PVE (odds ratio [OR]=1.5; 95% confidence interval (CI):1.16-1.94; p<0.01), aortic root replacement (OR=1.49; 95% CI:1.15-1.92; p<0.001), staphylococcus aureus (OR=1.5; 95% CI:1.23-1.82; p<0.001), and unplanned revascularization (OR=5.83; 95% CI:4.12-8.23; p<0.001) or mitral valve surgery (OR=2.29; 95% CI:1.5-3.51; p<0.001) correlated with a higher operative mortality, while prosthesis type (p=0.68) was not an independent predictor.

CONCLUSIONS

IE in the U.S. has risen over the past decade. However, operative mortality has decreased for both PVE and NVE. PVE, extension of IE requiring aortic root replacement, and additional unplanned surgical interventions carry an elevated mortality risk. Prosthesis selection did not impact operative mortality.

Social Disparities in Thoracic Surgery Database Research: Implications and Impact

A complex relationship exists between health care disparities and large databases among the thoracic surgical patient population. Using the example of thoracic malignancies, the ability of investigations leveraging large databases and novel analytical approaches to highlight disparate access to care and discordant outcomes following treatment is illustrated. Large, widely used databases may not be representative of the thoracic surgical patient population as a whole, and caution must be used when interpreting and generalizing results gleaned from such database analyses. Ensuring appropriate representation of all relevant patient subgroups in research databases will improve external generalizability and scientific validity of future investigations.

Association of Volume and Outcomes in 234,556 Patients Undergoing Surgical Aortic Valve Replacement

BACKGROUND

The relationship between institutional volume and operative mortality following SAVR remains unclear.

METHODS

From 1/2013 to 6/2018, 234,556 patients underwent isolated SAVR (n=144,177) or SAVR+CABG (n=90,379) within the STS ACSD. The association between annualized SAVR volume [Group 1 (1-25 SAVR), Group 2 (26-50 SAVR), Group 3 (51-100 SAVR), and Group 4 (>100 SAVR)] and operative mortality and composite major morbidity/mortality was assessed. Random effects models were used to evaluate whether historic (2013-2015) SAVR volume or risk-adjusted outcomes explained future (2016-2018) risk-adjusted outcomes.

RESULTS

The annualized median number of SAVRs per site was 35 [IQR: 22-59, isolated AVR: 20, AVR+CABG: 13]. Among isolated SAVR cases, the mean operative mortality and composite morbidity/mortality were 1.5% and 9.7%, respectively, at the highest volume sites (Group 4); with significantly higher rates among progressively lower volume groups (p-trend<0.001). After adjustment, lower volume centers experienced increased odds of operative mortality [Group 1 vs. 4 (Ref): AOR (SAVR), 2.24 (1.91-2.64); AOR (SAVR+CABG), 1.96 (1.67-2.30)] and major morbidity/mortality [AOR (SAVR), 1.53 (1.39-1.69); AOR (SAVR+CABG), 1.46 (1.32-1.61)] compared to the highest volume institutions. Substantial variation in outcomes was observed across hospitals within each volume category and prior outcomes explained a greater proportion of hospital operative outcomes than prior volume.

CONCLUSIONS

Operative outcomes following SAVR±CABG is inversely associated with institutional procedure volumes; however, prior outcomes are more predictive than prior volume of future outcomes. Given excellent outcomes observed at many lower volume hospitals, procedural outcomes may be preferable to procedural volumes as a quality metric.

Audit-Based Quality Validation of the Japan Cardiovascular Surgery Database

BACKGROUND

The Japan Cardiovascular Surgery Database (JCVSD) is a nationwide registry of patients undergoing cardiovascular surgery in Japan. To investigate and improve data quality, we have been conducting on-site institutional audits since 2004. This study aimed to investigate the accuracy of the registered data by comparing it to site visit data.Methods and Results:The subjects of this study were the 95 facilities at which a site visit was conducted. The case registration accuracy was 98.74%. Furthermore, we confirmed high data input accuracy of >90% for almost all fields. Approximately 99% of cases had been correctly entered for diabetes, aortic stenosis, and mortality. We also discovered which fields were more likely to be incorrectly captured and the causes thereof, as well as problems regarding some definitions and the input system itself.

CONCLUSIONS

We were able to confirm high registration accuracy in the JCVSD. Appropriately resourced, focused site visits as part of a national audit are capable of accurate data collection on which continual nationwide quality control can be based. Continued work and development to further improve the quality of the database are mandatory to maintain a high standard of cardiovascular surgery in Japan.

Administrative and clinical databases: General thoracic surgery perspective on approaches and pitfalls

Databases are created to serve 1 of 2 fundamental functions: (1) research and (2) benchmarking/quality. Their construction and nature affects the extent to which they can accomplish these functions.

Current Penetration, Completeness, and Representativeness of The Society of Thoracic Surgeons Adult Cardiac Surgery Database

BACKGROUND

The Society of Thoracic Surgeons (STS) Adult Cardiac Surgery Database (ACSD) is the largest cardiac surgical database in the world. Linked data from STS ACSD and the CMS Medicare database were used to determine contemporary completeness, penetration, and representativeness of STS ACSD.

METHODS

Using variables common to both STS and CMS databases, STS procedures were linked to CMS data for all CMS CABG discharges between 2000 and 2018, inclusive. For each CMS CABG hospitalization, it was determined whether a matching STS record existed.

RESULTS

Center-level penetration (number of CMS sites with at least one matched STS participant divided by total number of CMS CABG sites) increased from 45% in 2000 to 95% in 2018. In 2018, 949 of 1,004 CMS CABG sites (95%) were linked to an STS site. Patient-level penetration (number of CMS CABG hospitalizations at STS sites divided by total number of CMS CABG hospitalizations) increased from 51% in 2000 to 97% in 2018. In 2018, 68,584 of 70,818 CMS CABG hospitalizations (97%) occurred at an STS site. Completeness of case inclusion at STS sites (number of CMS CABG cases at STS sites linked to STS records divided by total number of CMS CABG cases at STS sites) increased from 88% in 2000 to 98% in 2018. In 2018, 66,673 of 68,108 CMS CABG hospitalizations at STS sites (98%) were linked to an STS record.

CONCLUSIONS

Linkage of STS and CMS databases demonstrates high and increasing penetration and completeness of STS ACSD. STS ACSD now includes 97% of CABG in USA.

Toward Dynamic Risk Prediction of Outcomes After Coronary Artery Bypass Graft: Improving Risk Prediction With Intraoperative Events Using Gradient Boosting

BACKGROUND

Intraoperative data may improve models predicting postoperative events. We evaluated the effect of incorporating intraoperative variables to the existing preoperative model on the predictive performance of the model for coronary artery bypass graft.

METHODS

We analyzed 378 572 isolated coronary artery bypass graft cases performed across 1083 centers, using the national Society of Thoracic Surgeons Adult Cardiac Surgery Database between 2014 and 2016. Outcomes were operative mortality, 5 postoperative complications, and composite representation of all events. We fitted models by logistic regression or extreme gradient boosting (XGBoost). For each modeling approach, we used preoperative only, intraoperative only, or pre+intraoperative variables. We developed 84 models with unique combinations of the 3 variable sets, 2 variable selection methods, 2 modeling approaches, and 7 outcomes. Each model was tested in 20 iterations of 70:30 stratified random splitting into development/testing samples. Model performances were evaluated on the testing dataset using the C statistic, area under the precision-recall curve, and calibration metrics, including the Brier score.

RESULTS

The mean patient age was 65.3 years, and 24.7% were women. Operative mortality, excluding intraoperative death, occurred in 1.9%. In all outcomes, models that considered pre+intraoperative variables demonstrated significantly improved Brier score and area under the precision-recall curve compared with models considering pre or intraoperative variables alone. XGBoost without external variable selection had the best C statistics, Brier score, and area under the precision-recall curve values in 4 of the 7 outcomes (mortality, renal failure, prolonged ventilation, and composite) compared with logistic regression models with or without variable selection. Based on the calibration plots, risk restratification for mortality showed that the logistic regression model underestimated the risk in 11 114 patients (9.8%) and overestimated in 12 005 patients (10.6%). In contrast, the XGBoost model underestimated the risk in 7218 patients (6.4%) and overestimated in 0 patients (0%).

CONCLUSIONS

In isolated coronary artery bypass graft, adding intraoperative variables to preoperative variables resulted in improved predictions of all 7 outcomes. Risk models based on XGBoost may provide a better prediction of adverse events to guide clinical care.

Incidence and predictors of postoperative ischemic stroke after coronary artery bypass grafting

BACKGROUND

Data on the incidence and outcomes of ischemic stroke in patients undergoing coronary artery bypass grafting (CABG) in the current era are limited. The goal of this study was to examine contemporary trends, predictors, and outcomes of ischemic stroke following CABG in a large nationally representative database over a 12-year-period.

METHODS

The National Inpatient Sample was used to identify all adult (≥18 years) patients who underwent CABG between 2004 and 2015. The incidence and predictors of post-CABG ischemic stroke were assessed and in-hospital outcomes of patients with and without post-CABG stroke were compared.

RESULTS

Out of 2 569 597 CABG operations, ischemic stroke occurred in 47 279 (1.8%) patients, with a rising incidence from 2004 (1.2%) to 2015 (2.3%) (P < .001). Patient risk profiles increased over time in both cohorts, with higher Charlson comorbidity scores observed amongst stroke patients. Stroke was independently associated with higher rates of in-hospital mortality (3-fold), longer lengths of hospital stay (~6 more days), and higher total hospitalisation cost (~$80 000 more). Age ≥60 years and female sex (OR 1.33, 95% CI 1.31-1.36) were the strongest predictors of stroke (both P < .001). Further, on-pump CABG was not an independent predictor of stroke (P = .784).

CONCLUSION

In this nationally representative study we have shown that the rates of postoperative stroke complications following CABG have increased over time to commensurate with a parallel increase in overall baseline patient risks. Given the adverse impact of stroke on in-hospital morbidity and mortality after CABG, further studies are warranted to systematically delineate factors contributing to this striking trend.

Impact of Postoperative Infections on Readmission and Resource Use in Elective Cardiac Surgery

BACKGROUND

Efforts to reduce postoperative infections have garnered national attention, leading to practice guidelines for cardiac surgical perioperative care. The present study characterized the impact of healthcare-acquired infection (HAI) on index hospitalization costs and post-discharge healthcare utilization.

METHODS

Adults undergoing elective coronary artery bypass grafting (CABG) and/or valve operations were identified in the 2016-2018 Nationwide Readmissions Database. Infections were categorized into bloodstream, gastrointestinal, pulmonary, surgical site, or urinary tract infections. Generalized linear or flexible hazard models were used to assess associations between infections and outcomes. Observed-to-expected (O/E) ratios were generated to examine inter-hospital variation in HAI.

RESULTS

Of an estimated 444,165 patients, 8.0% developed HAI. Patients with HAI were older, had a greater burden of chronic diseases, and more commonly underwent CABG/valve or multi-valve operations (all p<0.001). HAI was independently associated with mortality (odds ratio 4.02, 95% CI 3.67-4.40), non-home discharge (3.48, 95% CI 3.21-3.78), and a cost increase of $23,000 (95% CI 20,900-25,200). At 90 days, HAI was associated with greater hazard of readmission (1.29, 95% CI 1.24-1.35). Pulmonary infections had the greatest incremental impact on patient-level ($24,500, 95% CI 23,100-26,00) and annual cohort costs ($121.8 million, 95% CI 102.2-142.9 million). Significant hospital level variation in HAI was evident, with O/E ranging from 0.17 to 4.3 for cases performed in 2018.

CONCLUSIONS

Infections following cardiac surgery remain common and are associated with inferior outcomes and increased resource use. The presence of inter-hospital variation in this contemporary cohort emphasizes the ongoing need for systematic approaches in their prevention and management.

STS Adult Cardiac Surgery Database: 2021 Update on Outcomes, Quality, and Research

The Society of Thoracic Surgeons Adult Cardiac Surgery Database is the most mature and comprehensive cardiac surgery database. It has been the foundation for quality measurement and improvement activities in cardiac surgery, facilitated the generation of accurate risk adjusted performance benchmarks and serves as a platform for novel research. Recent enhancements have added to the database's functionality, ease of use, and value to multiple stakeholders. This report is the sixth in a series of annual reports that provide updated volumes, outcomes, database-related developments, quality improvement initiatives, and research summaries using the Adult Cardiac Surgery Database in the past year.

Monitoring the Impact of Aggressive Glycemic Intervention during Critical Care after Cardiac Surgery with a Glycemic Expert System for Nurse-Implemented Euglycemia: The MAGIC GENIE Project

A novel, multi-dimensional protocol named GENIE has been in use for intensive insulin therapy (IIT, target glucose <140 mg/dL) in the surgical intensive care unit (SICU) after open heart surgery (OHS) at VA Pittsburgh since 2005. Despite concerns over increased mortality from IIT after the publication of the NICE-SUGAR Trial, it remains in use, with ongoing monitoring under the MAGIC GENIE Project showing that GENIE performance over 12 years (2005-2016) aligns with the current consensus that IIT with target blood glucose (BG) <140 mg/dL is advisable only if it does not provoke severe hypoglycemia (SH). Two studies have been conducted to monitor glucometrics and outcomes during GENIE use in the SICU. One compares GENIE (n = 382) with a traditional IIT protocol (FORMULA, n = 289) during four years of contemporaneous use (2005-2008). The other compares GENIE's impact overall (n = 1404) with a cohort of patients who maintained euglycemia after OHS (euglycemic no-insulin [ENo-I], n = 111) extending across 12 years (2005-2016). GENIE performed significantly better than FORMULA during contemporaneous use, maintaining lower time-averaged glucose, provoking less frequent, severe, prolonged, or repetitive hypoglycemia, and achieving 50% lower one-year mortality, with no deaths from mediastinitis (0 of 8 cases vs 4 of 9 on FORMULA). Those benefits were sustained over the subsequent eight years of exclusive use in OHS patients, with an overall one-year mortality rate (4.2%) equivalent to the ENo-I cohort (4.5%). The results of the MAGIC GENIE Project show that GENIE can maintain tight glycemic control without provoking SH in patients undergoing OHS, and may be associated with a durable survival benefit. The results, however, await confirmation in a randomized control trial.

Coronary artery bypass graft surgery in Brazil from 2008 to 2017

BACKGROUND

Brazil is an upper middle-income country in South America with the world's sixth largest population. Despite great advances in health-care services and cardiac surgical care in both its public and private health systems, little is known on the volume, outcomes, and trends of coronary artery bypass grafting (CABG) in Brazil's public health system.

OBJECTIVE

The aim of this study was to evaluate the outcome of CABG on the public health system from January 2008 to December 2017 through the database DATASUS.

METHODS

This study is based on publicly available material obtained from DATASUS, the Brazilian Ministry of Health's data processing system, on numbers of surgical procedures, death rates, length of stay, and costs. Only isolated CABG procedures were included in our study. We used the TabNet software from the DATASUS website to generate reports. The χ² test was used to compare death rates. A p < .05 was considered statistically significant.

RESULTS

We identified 226,697 CABG procedures performed from January 2008 to December 2017. The overall in-hospital mortality over the 10-year period was 5.7%. We observed statistically significant differences in death rates between the five Brazilian macro-regions. Death rates by state ranged from 2.6% to 13.1%. The national average mortality rate remained stable over the course of time.

CONCLUSION

Over 10 years, a high volume of CABG was performed in the Brazilian Public Health System, with significant differences in mortality, number of procedures, and distribution of surgeries by region. Future databases involving all centers that perform CABG and carry out risk-adjusted analysis will help improve Brazilian results and enable policymakers to adopt appropriate health-care policies for greater transparency and accountability.

Aortic Annular Enlargement in the Elderly: Short and Long-Term Outcomes in the United States

BACKGROUND

Patient prosthesis mismatch is associated with significant long-term morbidity and mortality after aortic valve replacement, but the role and outcomes of annular enlargement (AE) remain poorly defined. We hypothesized that increasing rates of AE may lead to improved outcomes for patients at risk for severe patient prosthesis mismatch.

METHODS

Patients over age 65 years undergoing surgical aortic valve replacement with or without coronary artery bypass grafting from 2008-2016 in The Society of Thoracic Surgeons Adult Cardiac Surgery Database with matching Centers for Medicare & Medicaid Services data were included (n=189,268). Univariate, multivariate, and time-to-event analysis was used to evaluate the association between AE and early and late outcomes. Patients were stratified by projected degree of patient prosthesis mismatch based on calculated effective orifice area index.

RESULTS

A total of 5412 (2.9%) patients underwent AE. The Society of Thoracic Surgeons Adult Cardiac Surgery Database-predicted mortality was similar between AE and non-AE groups (2.97% vs 2.99%, P = .052). Patients undergoing AE had higher risk-adjusted rates of 30-day complications and death (5.4% vs 3.4%, P < .0001), but no differences in long-term rates of stroke, heart failure re-hospitalization,s or aortic valve reoperation. Survival analysis demonstrated a higher risk of mortality with AE during the first 3 years, after which the survival curves cross, favoring AE.

CONCLUSIONS

These data suggest that annular enlargement during surgical aortic valve replacement is associated with increased short-term risk in a Medicare population. Survival curves crossed after 3 years, which may portend a benefit in select patients. However, annular enlargement is still only performed in the minority of patients who are at risk for patient prosthesis mismatch.

Lower Survival After Coronary Artery Bypass in Patients Who Had Atrial Fibrillation Missed by Widely Used Definitions

Objective

To investigate the impact of limiting the definition of post-coronary artery bypass graft (CABG) atrial fibrillation (AF) to AF/flutter requiring treatment-as in the Society of Thoracic Surgeons' (STS) database- on the association with survival.

Patients and Methods

We assessed in-hospital incidence of post-CABG AF in 7110 consecutive isolated patients with CABG without preoperative AF at 4 hospitals (January 1, 2004 to December 31, 2010). Patients with ≥1 episode of post-CABG AF detected via continuous in-hospital electrocardiogram (ECG)/telemetry monitoring documented by physicians were assigned to the following: Group 1, identified as having post-CABG AF in STS data and Group 2, not identified as having post-CABG AF in STS data. Patients without documented post-CABG AF constituted Group 3. Survival was compared via a Cox model, adjusted for STS risk of mortality and accounting for site differences.

Results

Over 7 years' follow-up, 16.0% (295 of 1841) of Group 1, 18.7% (79 of 422) of Group 2, and 7.9% (382 of 4847) of Group 3 died. Group 2 had a significantly greater adjusted risk of death than both Group 1 (hazard ratio [HR]: 1.16; 95% confidence interval [CI], 1.02 to 1.33) and Group 3 (HR: 1.94; 95% CI, 1.69 to 2.22).

Conclusions

The statistically significant 16% higher risk of death for patients with AF post-CABG missed vs captured in STS data suggests treatment and postdischarge management should be investigated for differences. The historical misclassification of "missed" patients as experiencing no AF in the STS data weakens the ability to observe differences in risk between patients with and without post-CABG AF. Therefore, STS data should not be used for research examining post-CABG AF.

Persistent Racial and Sex Disparities in Outcomes After Coronary Artery Bypass Surgery: A Retrospective Clinical Registry Review in the Drug-eluting Stent Era

OBJECTIVE

The purpose of this study was to assess the temporal trends in 30-day mortality by race group for patients undergoing coronary artery bypass grafting (CABG) between 2011 and 2018 and to investigate the effect of race and sex on postoperative outcomes after CABG.

SUMMARY BACKGROUND DATA

Cardiovascular diseases remain a leading cause of death in the United States with studies demonstrating increased morbidity and mortality for black and female patients undergoing surgery. In the post drug-eluting stent era, studies of racial disparities CABG are outdated.

METHODS

We performed a retrospective analysis of the Society for Thoracic Surgeons database for patients undergoing CABG between 2011 and 2018. Primary outcome was 30-day mortality. Secondary outcomes included postoperative length of stay, surgical site infection, sepsis, pneumonia, stroke, reoperation, reintervention, early extubation, and readmission.

RESULTS

The study population was comprised of 1,042,506 patients who underwent isolated CABG between 2011 and 2018. Among all races, Black patients had higher rates of preoperative comorbidities. Compared with White patients, Black patients had higher overall mortality (2.76% vs 2.19%, P < 0.001). On univariable regression, Black patients had higher rates of death, infection, pneumonia, and postoperative stroke compared to White patients. On multivariable regression, Black patients had higher odds of 30-day mortality compared to white patients [odds ratio (OR) = 1.11, 95% confidence interval (CI) 1.05-1.18]. Similarly, female patients had higher odds of death compared to males (OR = 1.26, 95% CI 1.21-1.30).

CONCLUSIONS

In the modern era, racial and sex disparities in mortality and postoperative morbidity after coronary bypass surgery persist with Black patients and female patients consistently experiencing worse outcomes than White male patients. Although there may be unknown or underappreciated biological mechanisms at play, future research should focus on socioeconomic, cultural, and multilevel factors.

Volume-Outcome Association of Mitral Valve Surgery in the United States

Importance

Early surgery for severe primary degenerative mitral regurgitation is recommended, provided optimal outcomes are achievable. Contemporary national data defining mitral valve surgery volume and outcomes are lacking.

Objective

To assess national 30-day and 1-year outcomes of mitral valve surgery and define the hospital- and surgeon-level volume-outcome association with mitral valve repair or replacement (MVRR) in patients with primary mitral regurgitation.

Design, Setting, and Participants

This multicenter cross-sectional observational study used the Society of Thoracic Surgeons Adult Cardiac Surgery Database to identify patients undergoing isolated MVRR for primary mitral regurgitation in the United States. Operative data were collected from July 1, 2011, to December 31, 2016, and analyzed from March 1 to July 1, 2019, with data linked to the Centers for Medicare and Medicaid Services.

Main Outcomes and Measures

The primary outcome was 30-day in-hospital operative mortality after isolated MVRR for primary mitral regurgitation. Secondary outcomes were 30-day composite mortality plus morbidity (any occurrence of bleeding, stroke, prolonged ventilation, renal failure, or deep wound infection), rate of successful mitral valve repair of primary mitral regurgitation (residual mitral regurgitation of mild [1+] or better), and 1-year mortality, reoperation, and rehospitalization for heart failure.

Results

A total of 55 311 patients, 1094 hospitals, and 2410 surgeons were identified. Increasing hospital and surgeon volumes were associated with lower risk-adjusted 30-day mortality, lower 30-day composite mortality plus morbidity, and higher rate of successful repair. The lowest vs highest hospital volume quartile had higher 1-year risk-adjusted mortality (hazard ratio [HR], 1.61, 95% CI, 1.31-1.98), but not mitral reoperation (odds ratio [OR], 1.51; 95% CI, 0.81-2.78) or hospitalization for heart failure (HR, 1.25; 95% CI, 0.96-1.64). The surgeon-level 1-year volume-outcome associations were similar for mortality (HR, 1.60; 95% CI, 1.32-1.94) but not significant for mitral reoperation (HR, 1.14; 95% CI, 0.60-2.18) or hospitalization for heart failure (HR, 1.17; 95% CI, 0.91-1.50).

Conclusions and Relevance

National hospital- and surgeon-level inverse volume-outcome associations were observed for 30-day and 1-year mortality after mitral valve surgery for primary mitral regurgitation. These findings may help to define access to experienced centers and surgeons for the management of primary mitral regurgitation.

Patient and Hospital Characteristics of Mitral Valve Surgery in the United States

Importance

Volume metrics may have relevance in the evaluation of valve center expertise. However, a paucity of data exists regarding the quantity, volume, and geographic location of mitral valve (MV) surgical centers in the United States and the proportion of underserved populations they treat.

Objectives

To evaluate the hospital, patient, and procedural characteristics of mitral valve repair or replacement (MVRR) in the United States as a function of hospital procedure volume.

Design, Setting, and Participants

This cross-sectional, multicenter observational study was conducted from July 2014 to June 2018. Patients in the Society of Thoracic Surgeons Adult Cardiac Surgery Database undergoing any surgical procedure involving MVRR in the United States were included.

Main Outcomes and Measures

Volume distribution of MVRR by hospital and hospital referral region.

Results

There were 165 405 MVRRs performed in 1082 centers during the study period, of which 86 488 (52.3%) were MV repairs. There were 575 centers (53.1%) that performed 25 or more MVRRs per year. The geographic distribution of centers performing 25 or more MVRRs per year differed from those performing fewer than 25 MVRRs per year. Of 304 designated hospital referral regions, 235 (77.3%) had at least 1 center performing 25 or more MVRRs per year, representing accessibility to 1 or more such centers for 296.4 million of 320.1 million US residents (92.6% of the US population; Midwest, 60.0 million of 68.0 million [88.4%]; South, 112.6 million of 122.6 million [91.9%]; West, 68.6 million of 72.9 million [94.1%]; and Northeast, 54.9 million of 56.6 million [97.1%]). Of 304 hospital referral regions, 168 (55.3%) had at least 1 center performing 40 or more MVRRs per year, representing accessibility to 1 or more such centers for 259.8 million of 317.90 million (81.7%) of the US population (Midwest, 50.5 million of 67.9 million [74.5%]; South, 94.5 million of 121.1 million [78.1%]; West, 64.0 million of 72.8 million [88.0%]; Northeast, 50.1 million of 56.3 million [90.2%]). More black and Hispanic patients received operations in centers performing 25 or more MVRRs per year (22 984) vs those performing fewer than 25 MVRRs per year (3227), yet the proportion was higher in lower-volume centers (22 984 of 148 385 [15.5%] vs 3227 of 17 020 [19.0%]; P < .001). In centers performing 25 or more MVRRs per year vs fewer than 25 MVRRs per year, there was a lower percentage of Medicare and Medicaid patients (47 920 of 148 385 [32.3%] vs 6183 of 17 020 [.3%]; P < .001) and patients from rural zip codes (21 208 of 148 385 [14.3%] vs 3146 of 17 020 [18.5%]; P < .001).

Conclusions and Relevance

Fifty-three percent of all centers performed 25 or more MVRRs per year, and 92.6% of the US population lived in an hospital referral region with at least 1 such center. Disparities in race/ethnicity, rurality, and insurance status exist among patients being treated at centers with different volumes. These data indicate that efforts to centralize care based on volume metrics will need to balance access vs quality.

History of Serious Mental Illness Is a Predictor of Morbidity and Mortality in Cardiac Surgery

BACKGROUND

Serious mental illness (SMI), defined as a mental disorder causing functional impairment, affects 9.8 million Americans. SMI correlates with earlier onset, more extensive cardiac disease, and reduced life expectancy by 25 years. The impact of SMI on patients undergoing cardiac surgery has not been extensively studied. We hypothesized that patients with SMI have worse cardiac surgery outcomes.

METHODS

Using our institution's Society of Thoracic Surgeons database of 16,781 cardiac operations (2002-2017), a total of 1445 (8.7%) patients with SMI were identified and stratified into anxiety, mood disorders, and psychosis. The risk-adjusted impact on morbidity and mortality were evaluated using multivariable regression.

RESULTS

Patients with SMI were more often female patients, were younger, and had more comorbid disease. SMI patients were more likely to have had previous cardiac surgery and require urgent or emergent procedures (both P < .05). Among specific SMI diagnoses, patients with psychosis had worse outcomes compared with the general population, with higher operative mortality (9.1% vs 4.2%; P = .001), major morbidity (30.4% vs 15.8%; P < .0001), and cost ($50,211 vs $38,820; P < .001). After multivariable risk adjustment, SMI and psychosis remained independently associated with composite mortality and major morbidity (odds ratio, 1.21; P = .012; and odds ratio, 1.68; P = .003, respectively).

CONCLUSIONS

SMI is independently associated with morbidity and mortality after cardiac surgery. SMI patients, especially the subset with psychosis, are complicated, high-risk, and resource-consuming. Refined strategies to reduce postoperative complications and improve care coordination are necessary in this population.

The Evolving Burden of Drug Use Associated Infective Endocarditis in the United States

BACKGROUND

The rise in the number of valve operations performed for infective endocarditis (IE) due to drug use is an important manifestation of the opioid epidemic. This study characterized national trends and outcomes of valve surgery for drug use-associated IE (DU-IE).

METHODS

Adults undergoing valve surgery for active IE in The Society of Thoracic Surgeons (STS) Adult Cardiac Surgery Database between July 2011 and June 2018 were stratified as DU-IE and non-DU-IE. Trends and clinical profiles were analyzed. Early outcomes were assessed. The association of DU-IE with outcomes was analyzed with multivariable regression, adjusting for STS Valve Risk model covariates.

RESULTS

There were 34,905 valve operations performed for IE, of which 33.7% were for DU-IE. DU-IE operations increased 2.7-fold during the study period. There was considerable regional variability in DU-IE operations, ranging from 28% to 58% of all IE surgeries in 2018, with highest rates observed in East South Central and South Atlantic regions. DU-IE patients were younger and had fewer cardiovascular comorbidities. Risk-adjusted major morbidity and in-hospital mortality were significantly higher in the DU-IE group. Redo valve procedures in DU-IE patients were associated with worse outcomes, compared with those receiving a first valve operation.

CONCLUSIONS

Operations for DU-IE have increased sharply in the United States during the last several years, exhibiting substantial regional variability. DU-IE patients have unique clinical profiles, and worse risk-adjusted outcomes. This demonstrates the significant impact of the opioid epidemic on endocarditis surgeries and punctuates the urgent need for multidisciplinary regional and national efforts to reverse this trend.

The Society of Thoracic Surgeons National Database 2019 Annual Report

The Society of Thoracic Surgeons (STS) National Database was established in 1989 as an initiative for quality improvement and patient safety for cardiothoracic surgery. The STS National Database has 4 components, each focusing on a distinct discipline-Adult Cardiac Surgery, General Thoracic Surgery, Congenital Heart Surgery, and mechanical circulatory support with the STS Interagency Registry for Mechanical Circulatory Support (Intermacs)/Pediatric Interagency Registry for Mechanical Circulatory Support (Pedimacs) Database. In December 2015, The Annals of Thoracic Surgery began publishing a monthly series of scholarly articles on outcomes analysis, quality improvement, and patient safety. This article provides the fourth annual summary of the status of the STS National Database.

Using a society database to evaluate a patient safety collaborative: the Cardiovascular Surgical Translational Study

AIM

To assess the utility of using external databases for quality improvement (QI) evaluations in the context of an innovative QI collaborative aimed to reduce three infections and improve patient safety across the cardiac surgery service line.

METHODS

We compared changes in each outcome between 15 intervention hospitals (infection reduction protocols plus safety culture intervention) and 52 propensity score-matched hospitals (feedback only).

RESULTS

Improvement trends in several outcomes among the intervention hospitals were not statistically different from those in comparison hospitals.

CONCLUSION

Using external databases such as those of professional societies may permit comparative effectiveness assessment by providing concurrent comparison groups, additional outcome measures and longer follow-up. This can better inform evaluation of continuous QI in healthcare organizations.

Association Between Left Atrial Appendage Occlusion and Readmission for Thromboembolism Among Patients With Atrial Fibrillation Undergoing Concomitant Cardiac Surgery

IMPORTANCE

The left atrial appendage is a key site of thrombus formation in atrial fibrillation (AF) and can be occluded or removed at the time of cardiac surgery. There is limited evidence regarding the effectiveness of surgical left atrial appendage occlusion (S-LAAO) for reducing the risk of thromboembolism.

OBJECTIVE

To evaluate the association of S-LAAO vs no receipt of S-LAAO with the risk of thromboembolism among older patients undergoing cardiac surgery.

DESIGN, SETTING, AND PARTICIPANTS

Retrospective cohort study of a nationally representative Medicare-linked cohort from the Society of Thoracic Surgeons Adult Cardiac Surgery Database (2011-2012). Patients aged 65 years and older with AF undergoing cardiac surgery (coronary artery bypass grafting [CABG], mitral valve surgery with or without CABG, or aortic valve surgery with or without CABG) with and without concomitant S-LAAO were followed up until December 31, 2014.

EXPOSURES

S-LAAO vs no S-LAAO.

MAIN OUTCOMES AND MEASURES

The primary outcome was readmission for thromboembolism (stroke, transient ischemic attack, or systemic embolism) at up to 3 years of follow-up, as defined by Medicare claims data. Secondary end points included hemorrhagic stroke, all-cause mortality, and a composite end point (thromboembolism, hemorrhagic stroke, or all-cause mortality).

RESULTS

Among 10 524 patients undergoing surgery (median age, 76 years; 39% female; median CHA2DS2-VASc score, 4), 3892 (37%) underwent S-LAAO. Overall, at a mean follow-up of 2.6 years, thromboembolism occurred in 5.4%, hemorrhagic stroke in 0.9%, all-cause mortality in 21.5%, and the composite end point in 25.7%. S-LAAO, compared with no S-LAAO, was associated with lower unadjusted rates of thromboembolism (4.2% vs 6.2%), all-cause mortality (17.3% vs 23.9%), and the composite end point (20.5% vs 28.7%) but no significant difference in rates of hemorrhagic stroke (0.9% vs 0.9%). After inverse probability-weighted adjustment, S-LAAO was associated with a significantly lower rate of thromboembolism (subdistribution hazard ratio [HR], 0.67; 95% CI, 0.56-0.81; P < .001), all-cause mortality (HR, 0.88; 95% CI, 0.79-0.97; P = .001), and the composite end point (HR, 0.83; 95% CI, 0.76-0.91; P < .001) but not hemorrhagic stroke (subdistribution HR, 0.84; 95% CI, 0.53-1.32; P = .44). S-LAAO, compared with no S-LAAO, was associated with a lower risk of thromboembolism among patients discharged without anticoagulation (unadjusted rate, 4.2% vs 6.0%; adjusted subdistribution HR, 0.26; 95% CI, 0.17-0.40; P < .001), but not among patients discharged with anticoagulation (unadjusted rate, 4.1% vs 6.3%; adjusted subdistribution HR, 0.88; 95% CI, 0.56-1.39; P = .59).

CONCLUSIONS AND RELEVANCE

Among older patients with AF undergoing concomitant cardiac surgery, S-LAAO, compared with no S-LAAO, was associated with a lower risk of readmission for thromboembolism over 3 years. These findings support the use of S-LAAO, but randomized trials are necessary to provide definitive evidence.

Metformin therapy and postoperative atrial fibrillation in diabetic patients after cardiac surgery

Background

Postoperative atrial fibrillation (AF) commonly occurs in cardiac surgery patients. Studies suggest inflammation and oxidative stress contribute to postoperative AF development in this patient population. Metformin exerts an anti-inflammatory effect that reduces oxidative stress and thus may play a role in preventing postoperative AF.

Methods

We conducted a matched, retrospective cohort study of diabetic patients’ age ≥18 undergoing a coronary artery bypass graft (CABG) and/or cardiac valve surgery from January 1, 2009, to November 30, 2014. We extracted data from The Society of Thoracic Surgeons National Adult Cardiac Surgery Database. Primary exposure was ongoing metformin use at a dose of ≥ 500 mg in effect before cardiac surgery as captured before admission. Primary study outcome was postoperative AF incidence. Matching was used to reduce selection bias between metformin and non-metformin groups. Comparison between the groups after matching was accomplished using the McNemar test or paired t test.

Results

Out of the 4177 patients with cardiac surgery (CABG and/or valve surgery), 1283 patients met our study criteria. These patients were grouped into metformin [n = 635 (49.5%)] and non-metformin [n = 648 (50.5%)] users. Pre-matching, postoperative AF was found in 149 (23.5%) patients in the metformin group and 172 (26.5%) in the non-metformin group (p = 0.2088). Matching resulted in a total of 114 patients in each group (metformin vs. non-metformin). We found no statistically significant difference for postoperative AF between the two groups after matching (p = 0.8964).

Conclusions

Prior use of metformin therapy in diabetic patients undergoing cardiac surgery was not associated with decreased rate of postoperative AF.