Persistent income-based disparities in clinical outcomes of cardiac surgery across the United States: A contemporary appraisal.

Objective: Although national efforts have aimed to improve the safety of inpatient operations, income-based inequities in surgical outcomes persist, and the evolution of such disparities has not been examined in the contemporary setting. We sought to examine the association of community-level household income with acute outcomes of cardiac procedures over the past decade. Methods: All adult hospitalizations for elective coronary artery bypass grafting/valve operations were tabulated from the 2010-2020 Nationwide Readmissions Database. Patients were stratified into quartiles of income, with records in the 76th to 100th percentile designated as highest and those in the 0 to 25th percentile as lowest. To evaluate the change in adjusted risk of in-hospital mortality, complications, and readmission over the study period, estimates were generated for each income level and year. Results: Of approximately 1,848,755 hospitalizations, 406,216 patients (22.0%) were classified as highest income and 451,988 patients (24.4%) were classified as lowest income. After risk adjustment, lowest income remained associated with greater likelihood of in-hospital mortality (adjusted odds ratio, 1.61, 95% CI, 1.51-1.72), any postoperative complication (adjusted odds ratio, 1.19, CI, 1.15-1.22), and nonelective readmission within 30 days (adjusted odds ratio, 1.07, CI, 1.05-1.10). Overall adjusted risk of mortality, complications, and nonelective readmission decreased for both groups from 2010 to 2020 (P < .001). Further, the difference in risk of mortality between patients of lowest and highest income decreased by 0.2%, whereas the difference in risk of major complications declined by 0.5% (both P < .001). Conclusions: Although overall in-hospital mortality and complication rates have declined, low-income patients continue to face greater postoperative risk. Novel interventions are needed to address continued income-based disparities and ensure equitable surgical outcomes.

Development and preliminary assessment of a machine learning model to predict myocardial infarction and cardiac arrest after major operations.

INTRODUCTION: Accurate prediction of complications often informs shared decision-making. Derived over 10 years ago to enhance prediction of intra/post-operative myocardial infarction and cardiac arrest (MI/CA), the Gupta score has been criticized for unreliable calibration and inclusion of a wide spectrum of unrelated operations. In the present study, we developed a novel machine learning (ML) model to estimate perioperative risk of MI/CA and compared it to the Gupta score. METHODS: Patients undergoing major operations were identified from the 2016-2020 ACS-NSQIP. The Gupta score was calculated for each patient, and a novel ML model was developed to predict MI/CA using ACS NSQIP-provided data fields as covariates. Discrimination (C-statistic) and calibration (Brier score) of the ML model were compared to the existing Gupta score within the entire cohort and across operative subgroups. RESULTS: Of 2,473,487 patients included for analysis, 25,177 (1.0%) experienced MI/CA (55.2% MI, 39.1% CA, 5.6% MI and CA). The ML model, which was fit using a randomly selected training cohort, exhibited higher discrimination within the testing dataset compared to the Gupta score (C-statistic 0.84 vs 0.80, p < 0.001). Furthermore, the ML model had significantly better calibration in the entire cohort (Brier score 0.0097 vs 0.0100). Model performance was markedly improved among patients undergoing thoracic, aortic, peripheral vascular and foregut surgery. CONCLUSIONS: The present ML model outperformed the Gupta score in the prognostication of MI/CA across a heterogenous range of operations. Given the growing integration of ML into healthcare, such models may be readily incorporated into clinical practice and guide benchmarking efforts.

Off-Pump Coronary Artery Bypass Grafting Does Not Confer Superior Outcomes Among Frail Patients.

Off-pump coronary revascularization (OPCAB) has been proposed to benefit patients who are at a greater surgical risk because it avoids the use of extracorporeal circulation. Although, historically, older patients were considered high-risk candidates, recent studies implicate frailty as a more comprehensive measure of perioperative fitness. Yet, the outcomes of OPCAB in frail patients have not been elucidated. Thus, using a national cohort of frail patients, we assessed the impact of OPCAB relative to on-pump coronary revascularization (ONCAB). Patients who underwent first-time elective coronary revascularization were tabulated from the 2010 to 2020 Nationwide Readmissions Database. Frailty was assessed using the previously-validated Johns Hopkins Adjusted Clinical Groups indicator. Multivariable models were used to consider the independent associations between OPCAB and the key outcomes. Of ∼26,529 frail patients, 6,322 (23.8%) underwent OPCAB. After risk adjustment and compared with ONCAB, OPCAB was linked with similar odds of in-hospital mortality but greater likelihood of postoperative cardiac arrest (adjusted odds ratio [AOR] 1.53, confidence interval [CI] 1.13 to 2.07) and myocardial infarction (AOR 1.44, CI 1.23 to 1.69). OPCAB was further associated with greater odds of postoperative infection (AOR 1.22, CI 1.02 to 1.47) but decreased need for blood transfusion (AOR 0.68, CI 0.60 to 0.77). In addition, OPCAB faced a +0.86-day increase in length of stay (CI 0.21 to 1.51) but similar costs (ß $1,610, CI -$1,240 to 4,460) relative to ONCAB. Although OPCAB was associated with no difference in mortality compared with ONCAB, it was linked with greater likelihood of postoperative cardiac arrest and myocardial infarction. Our findings demonstrate that ONCAB remains associated with superior outcomes, even in the growing population of frail patients who underwent coronary revascularization.

National outcomes of expedited discharge following esophagectomy for malignancy.

BACKGROUND: Expedited discharge following esophagectomy is controversial due to concerns for higher readmissions and financial burden. The present study aimed to evaluate the association of expedited discharge with hospitalization costs and unplanned readmissions following esophagectomy for malignant lesions. METHODS: Adults undergoing elective esophagectomy for cancer were identified in the 2014-2019 Nationwide Readmissions Database. Patients discharged by postoperative day 7 were considered Expedited and others as Routine. Patients who did not survive to discharge or had major perioperative complications were excluded. Multivariable regression models were constructed to assess association of expedited discharge with index hospitalization costs as well as 30- and 90-day non-elective readmissions. RESULTS: Of 9,886 patients who met study criteria, 34.6% comprised the Expedited cohort. After adjustment, female sex (adjusted odds ratio [AOR] 0.71, p = 0.001) and increasing Elixhauser Comorbidity Index (AOR 0.88/point, p<0.001) were associated with lower odds of expedited discharge, while laparoscopic (AOR 1.63, p<0.001, Ref: open) and robotic (AOR 1.67, p = 0.003, Ref: open) approach were linked to greater likelihood. Patients at centers in the highest-tertile of minimally invasive esophagectomy volume had increased odds of expedited discharge (AOR 1.52, p = 0.025, Ref: lowest-tertile). On multivariable analysis, expedited discharge was independently associated with an $8,300 reduction in hospitalization costs. Notably, expedited discharge was associated with similar odds of 30-day (AOR 1.10, p = 0.40) and 90-day (AOR 0.90, p = 0.70) unplanned readmissions. CONCLUSION: Expedited discharge after esophagectomy was associated with decreased costs and unaltered readmissions. Prospective studies are necessary to robustly evaluate whether expedited discharge is appropriate for select patients undergoing esophagectomy.

Center-Level Variation in Hospitalization Costs of Transcatheter Aortic Valve Replacement.

BACKGROUND: Using a nationally representative database, the present study evaluated the degree of center-level variation in the cost of transcatheter aortic valve replacement (TAVR). METHODS: All adults undergoing elective, isolated TAVR were identified in the 2016 to 2018 Nationwide Readmissions Database. Multilevel mixed-effects models were used to identify patient and hospital characteristics associated with hospitalization costs. The random intercept for each hospital was generated and considered to be the baseline cost attributable to care at each center. Hospitals in the highest decile of baseline costs were classified as high-cost hospitals. The association of high-cost hospital status with in-hospital mortality and perioperative complications was subsequently assessed. RESULTS: An estimated 119,492 patients, with a mean age of 80 years and a 45.9% prevalence of female sex, met the study criteria. Analysis of random intercepts indicated that 54.3% of variability in costs was attributable to interhospital differences rather than patient factors. Perioperative respiratory failure, neurologic complications, and acute kidney injury were associated with increased episodic expenditure but did not explain the observed center-level variation. The baseline cost associated with each hospital ranged from -$26,000 to $162,000. Notably, high-cost hospital status was not linked to annual TAVR caseload or to odds of mortality (P = .83), acute kidney injury (P = .18), respiratory failure (P = .32), or neurologic complications (P = .55). CONCLUSIONS: The present analysis identified significant variation in the cost of TAVR, which was largely attributable to center-level rather than patient factors. Hospital TAVR volume and occurrence of complications were not drivers of the observed variation.

Association of prior bariatric surgery with financial and clinical outcomes of acute myocardial infarction.

BACKGROUND: Superior clinical outcomes after hospitalization for cardiovascular-related disease such as acute heart failure have been linked with prior history of bariatric surgery, but similar analyses in acute myocardial infarction (MI) are currently limited. OBJECTIVE: This work examines clinical outcomes and resource utilization in patients with acute MI hospitalizations with a prior history of bariatric surgery. SETTING: Academic university-affiliated hospital in the United States. METHODS: All adult patients with hospitalizations with a primary diagnosis of acute MI were queried using the 2016-2020 Nationwide Readmissions Database. The study population was comprised of patients with an International Classification of Diseases, Tenth Revision (ICD-10) diagnosis code for obesity (body mass index ≥35 kg/m2) as well as those with a prior history of bariatric surgery regardless of their body mass index status. Comparison was made between those with a prior history of bariatric surgery and those without. Univariate analysis and multivariate regression models were used to examine the association between bariatric surgery and outcomes of interest, which included in-hospital mortality, medical complications, and resource utilization. RESULTS: Of an estimated 2,736,606 hospitalizations for acute MI, 296,902 patients (10.8%) had a diagnosis of obesity and/or a prior history of bariatric surgery. The bariatric cohort was more frequently female and had a lower prevalence of congestive heart failure, chronic lung disease, diabetes, and electrolyte derangements than the nonbariatric cohort. After risk adjustment, prior history of bariatric surgery was associated with significantly lower odds of in-hospital mortality, cardiogenic shock, and acute kidney injury. Additionally, prior history of bariatric surgery was linked to a decreased duration of hospital stay and lower hospitalization costs as well as lower odds of nonhome discharge. CONCLUSION: Among acute MI patients with obesity, prior history of bariatric surgery was associated with decreased odds of in-hospital mortality, improved clinical outcomes, and lower resource utilization. Expansion of bariatric surgery programs may provide improved access to a medical intervention that is intertwined with cardiovascular health.

Moving beyond frailty: Obesity paradox persists in lung resection.

BACKGROUND: The apparent protective effect of high body mass index on postoperative outcomes, termed the "obesity paradox," has been postulated to reflect the relative frailty of patients without obesity. We wanted to examine the independent association between body mass index and outcomes after anatomic lung resection. METHODS: All adults undergoing elective lung resection for cancer were identified in the 2012-2020 National Surgical Quality Improvement Program. The modified Frailty Index quantified degree of patient frailty. Malnutrition was defined as a preoperative serum albumin <3.5g/dL. Multivariable regressions were used to examine the independent association of body mass index and major adverse events, analyzed as a composite of 30-day mortality, postoperative complications, and unplanned reoperation. RESULTS: Of an estimated 20,099 patients meeting study criteria, 6,424 (32.0%) had obesity. Relative to others, patients with obesity were significantly younger (49.3 vs 50.3 years), more commonly White (78.1 vs 74.9%), and more frequently frail (modified Frailty Index >1: 35.7 vs 22.5%, all P < .001). There was no significant difference in malnutrition rates (7.6 vs 8.4%, P = .05) or extent of resection between groups. After adjustment, obesity was associated with decreased odds of major adverse events (adjusted odds ratio 0.86, 95% confidence interval 0.78-0.94). CONCLUSION: The present findings uphold the canonical obesity paradox in anatomic lung resection, despite adjustment for frailty and malnutrition. Further studies are warranted to characterize the nature of this association; however, our results may inform efforts to optimize risk stratification and patient selection for surgical intervention.

Association of Hospital Volume and Outcomes Following Off-Pump Coronary Artery Bypass Grafting.

BACKGROUND: Off-pump coronary artery bypass grafting (OPCAB) has been used to mitigate the negative systemic effects of cardiopulmonary bypass. Recent consortium and single-institution studies suggest an association between operator experience and long-term survival. We thus aimed to ascertain the relationship between institutional OPCAB volume and outcomes using a contemporary nationwide all-payer database. METHODS: Adult admissions for elective isolated OPCAB were identified from the 2016-2019 Nationwide Readmissions Database. The primary outcome was major adverse events (MAE), defined as a composite of mortality, reoperation, prolonged mechanical ventilation, acute kidney injury requiring dialysis, or perioperative stroke during the index hospitalisation. Secondary outcomes included temporal trends, postoperative length of stay (pLOS), hospitalisation costs, non-home discharge, and 30-day readmission rate. High-volume hospitals (HVH) were defined to have annual caseloads >35 based on cubic spline analysis. RESULTS: Of an estimated 41,154 patients, 59.9% were treated at HVH. The proportion of coronary artery bypass grafting operations that were OPCAB significantly decreased from 21.1% in 2016 to 18.3% in 2019. After adjustment, HVH status was associated with lower adjusted odds of MAE (adjusted odds ratio [AOR] 0.78, 95% confidence interval [CI] 0.70-0.88), compared to others. HVH were also associated with shorter pLOS (ß -0.10, 95% -0.13, -0.07), reduced costs (ß -US$4,900, - US$6,300, - US$3,600), non-home discharge (AOR 0.54, 95% CI 0.45-0.64), and 30-day readmission (AOR 0.86, 95% CI 0.77-0.96). CONCLUSIONS: Our results suggest that OPCAB requires a distinct set of surgical expertise and institutional aptitude. As a result, centralisation of care to centres of excellence should be considered.

Failure to rescue among octogenarians undergoing cardiac surgery in the United States.

BACKGROUND: A rapidly growing population, octogenarians are considered at high-risk for mortality and complications after cardiac surgery. Given the recent addition of failure to rescue as a Society of Thoracic Surgeons quality metric, a better understanding of patient and operative factors predictive of failure to rescue in this cohort is warranted. METHODS: The 2010-2020 Nationwide Readmissions Database was used to identify all patients ≥80 years undergoing first-time, elective coronary artery bypass grafting or concomitant valve operations. Patients experiencing failure to rescue, defined as mortality after a major or minor complication, were classified as Failure to Rescue (others: Non-Failure to Rescue). Multivariable regression models were developed to ascertain significant perioperative factors associated with failure to rescue. RESULTS: Of ∼562,794 octogenarian patients, 76,473 (13.6%) developed complications. Of these, 7,055 (9.2%) experienced failure to rescue. The incidence of failure to rescue decreased across the study time course (9.7% in 2010 to 7.6% in 2019, P = .001). After risk adjustment, age (adjusted odds ratio, 1.05/year; 95% confidence interval, 1.03-1.07), female sex (adjusted odds ratio, 1.40; 95% confidence interval, 1.27-1.53), congestive heart failure (adjusted odds ratio, 1.54; 95% confidence interval, 1.38-1.71), late-stage kidney disease (adjusted odds ratio, 2.38; 95% confidence interval, 1.79-3.17), liver disease (adjusted odds ratio, 9.59; 95% confidence interval, 8.17-11.26), and cerebrovascular disease (adjusted odds ratio, 2.42; 95% confidence interval, 2.12-2.76) were associated with failure to rescue. Relative to isolated coronary artery bypass grafting, combined coronary artery bypass grafting-valve (adjusted odds ratio, 1.67; 95% confidence interval, 1.43-1.95) and multi-valve procedures (adjusted odds ratio, 2.23; 95% confidence interval, 1.75-2.85) were linked with greater odds of failure to rescue. There was no association between failure to rescue and hospital volume. CONCLUSION: Despite improvements in perioperative management, failure to rescue occurs in ∼9% of octogenarians undergoing elective cardiac operations. Although incidence has declined over the past decade, the continued prevalence of failure to rescue underscores the need for novel risk assessments and targeted interventions.

Volume-outcome relationship in septal myectomy for hypertrophic obstructive cardiomyopathy.

BACKGROUND: Septal myectomy is the gold standard treatment for refractory hypertrophic obstructive cardiomyopathy. The present study characterized the association of septal myectomy volume and cardiac surgery volume with outcomes after septal myectomy. METHODS: Adults undergoing septal myectomy for hypertrophic obstructive cardiomyopathy were identified in the 2016 to 2019 Nationwide Readmissions Database. Centers were grouped into low-, medium-, and high-volume hospitals by tertiles based on institutional septal myectomy caseload. Overall cardiac surgery volume was similarly assessed. Generalized linear models were used to test the association between hospital septal myectomy or cardiac surgery volume and in-hospital mortality, mitral valve repair, and 90-day non-elective readmission. RESULTS: Of 3,337 patients, 30.8% underwent septal myectomy at high-volume hospitals, whereas 39.1% were managed at low-volume hospitals. Patients at high-volume hospitals had a similar burden of comorbidities at low-volume hospitals, although congestive heart failure was more prevalent at high-volume hospitals. Despite comparable rates of mitral regurgitation, patients more commonly avoided mitral valve intervention at high-volume hospitals compared with low-volume hospitals (72.9% vs 68.3%; P = .007). After risk adjustment, high-volume hospital status was associated with reduced odds of mortality (0.24; 95% CI, 0.08-0.77) and readmission (0.59; 95% CI, 0.3-0.97). Among cases requiring mitral intervention, high-volume hospital status was associated with greater odds of valve repair (5.33; 95% CI, 2.54-11.13) relative to low-volume hospitals. Overall cardiac surgery volume was not associated with any studied outcome. CONCLUSION: Greater septal myectomy volume, but not overall cardiac surgery volume, was associated with reduced mortality and greater mitral valve repair relative to replacement after septal myectomy. These findings suggest that septal myectomy for hypertrophic obstructive cardiomyopathy should be performed at centers with expertise in this operation.

Sociodemographic disparities in concomitant left atrial appendage occlusion during cardiac valve operations.

BACKGROUND: Sociodemographic disparities in atrial fibrillation (AF) management and thromboembolic prophylaxis have previously been reported, which may involve inequitable access to left atrial appendage occlusion (LAAO) during cardiac surgery. The present study aimed to evaluate the association of LAAO utilization with sex, race, and hospital region among patients with AF undergoing heart valve operations. METHODS: Adults with AF undergoing valve replacement/repair in the 2012-2019 National Inpatient Sample were identified and stratified based on concurrent LAAO. Multivariable linear and logistic regressions were developed to identify factors associated with LAAO utilization. Mortality, complications including stroke and thromboembolism, hospitalization costs and length of stay (LOS) were secondarily assessed. RESULTS: Of 382,580 patients undergoing valve operations, 18.7% underwent concomitant LAAO. Over the study period, the proportion of female patients receiving LAAO significantly decreased from 44.8% to 38.9% (p<0.001). Upon risk adjustment, female (AOR 0.93 [95% CI 0.89-0.97]) and Black patients (0.91 [0.83-0.99]) had significantly reduced odds of undergoing LAAO compared to males and Whites, respectively. Additionally, hospitals in the Midwest (1.38 [1.24-1.51]) and West (1.26 [1.15-1.36]) had increased likelihood of LAAO whereas Northeast hospitals (0.85 [0.77-0.94)] had decreased odds relative to the South. Furthermore, LAAO was associated with decreased stroke (0.71 [0.60-0.84]) and thromboembolism (0.68 [0.54-0.86]), $4,200 reduction in costs and 1-day decrement in LOS. CONCLUSIONS: Female and Black patients had significantly lower odds while Midwest and Western hospitals had greater odds of LAAO utilization. Enhancing access to LAAO during valvular surgery is warranted to improve clinical and financial outcomes for patients with AF.

Acute clinical and financial outcomes of on- versus off-pump coronary artery bypass grafting in octogenarians.

BACKGROUND: Coronary artery bypass surgery in octogenarians is associated with increased postoperative morbidity. Off-pump coronary artery bypass surgery eliminates potential complications of cardiopulmonary bypass, but its use remains controversial. This study aimed to evaluate the clinical and financial impact of off-pump coronary artery bypass surgery compared to conventional coronary artery bypass surgery among this high-risk population. METHODS: Patients ≥80 years undergoing first-time, isolated, elective coronary artery bypass surgery were identified using the 2010-2019 Nationwide Readmissions Database. Patients were grouped into off-pump or conventional coronary artery bypass surgery cohorts. Multivariable models were developed to assess the independent associations between off-pump coronary artery bypass surgery and key outcomes. RESULTS: Of ∼56,158 patients, 13,940 (24.8%) underwent off-pump coronary artery bypass surgery. On average, the off-pump cohort was more likely to undergo single-vessel bypass (37.3 vs 19.7%, P < .001). After adjustment, undergoing off-pump coronary artery bypass surgery was associated with similar odds of in-hospital mortality (adjusted odds ratio 0.90, 95% confidence interval 0.73-1.12) relative to conventional bypass. Additionally, the off-pump and conventional coronary artery bypass surgery groups were comparable in odds of postoperative stroke (adjusted odds ratio 1.03, 95% confidence interval 0.78-1.35), cardiac arrest (adjusted odds ratio 0.99, 95% confidence interval 0.71-1.37), ventricular fibrillation (adjusted odds ratio 0.89, 95% confidence interval 0.60-1.31), tamponade (adjusted odds ratio 1.21, 95% confidence interval 0.74-1.97), and cardiogenic shock (adjusted odds ratio 0.94, 95% confidence interval 0.75-1.17). However, the off-pump coronary artery bypass surgery cohort was linked with an increased likelihood of ventricular tachycardia (adjusted odds ratio 1.23, 95% confidence interval 1.01-1.49) and myocardial infarction (adjusted odds ratio 1.34, 95% confidence interval 1.16-1.55). Furthermore, those undergoing off-pump coronary artery bypass surgery demonstrated reduced odds of non-home discharge (adjusted odds ratio 0.91, 95% confidence interval 0.83-0.99) and a decrement in hospitalization expenditures ($-1,290, 95% confidence interval -$2,370 to $200). CONCLUSION: Off-pump coronary artery bypass surgery was linked with increased odds of ventricular tachycardia and myocardial infarction, but no difference in mortality. Our findings point to the safety of conventional coronary artery bypass surgery in octogenarians. Yet, future work is needed to consider long-term outcomes in this complex surgical cohort.

Acute Outcomes of Cardiac Operations in Patients With Autoimmune Disorders: A National Analysis.

BACKGROUND: Accelerated atherosclerosis, inflammation, and valve pathology are known complications of autoimmune connective tissue diseases (AID). However, outcomes of coronary artery bypass graft surgery (CABG) or valve operations among these patients remain underexamined. METHODS: All adult hospitalizations for elective CABG or valve procedures were identified from the 2010-2019 Nationwide Readmissions Database. Autoimmune connective tissue disease was defined to include systemic lupus erythematosus (SLE), antiphospholipid syndrome (APLS), polymyalgia rheumatica (PMR), and other autoimmune AIDs. Entropy balancing was applied to generate balanced patient cohorts. Multivariable regression models were constructed to assess the independent associations between AID and outcomes of interest. RESULTS: Of ∼1 652 573 patients, 21 019 (1.3%) had AID (23.7% SLE, 17.2% APLS, 29.5% PMR, and 29.6% other). Autoimmune connective tissue disease patients were more frequently female (60.8 vs 33.1%, P < .001) and insured by Medicare (71.4 vs 62.2%, P < .001) and presented with a higher comorbidity index (5.2 ± 1.8 vs 4.1 ± 1.8, P < .001). Further, AID less frequently underwent isolated CABG (39.0 vs 52.3%) but more commonly isolated valve operations (41.9% vs 31.0%, P < .001), relative to non-AID. Following risk-adjustment, AID was not linked with increased odds of mortality or cardiac complications. However, AID was linked with a greater risk of thrombotic complications, blood transfusion, and non-elective readmission within 30 days, as well as a +$900 decrement in hospitalization costs. DISCUSSION: Autoimmune connective tissue disease patients demonstrated acceptable outcomes following CABG and valve procedures. However, novel prophylactic care pathways should be developed and instituted to address greater thrombotic and blood transfusion risk. Further investigation is needed to identify factors contributing to greater non-elective readmissions among these patients.

Evaluation of hospital readmission rates as a quality metric in adult cardiac surgery.

OBJECTIVE: To assess the reliability of 30-day non-elective readmissions as a quality metric for adult cardiac surgery. BACKGROUND: Unplanned readmissions is a quality metric for adult cardiac surgery. However, its reliability in benchmarking hospitals remains under-explored. METHODS: Adults undergoing elective isolated coronary artery bypass grafting (CABG), surgical aortic valve replacement/repair (SAVR) or mitral valve replacement/repair (MVR) were tabulated from 2019 Nationwide Readmissions Database. Multi-level regressions were developed to model the likelihood of 30-day unplanned readmissions and major adverse events (MAE). Random intercepts were estimated, and associations between hospital-specific risk-adjusted rates of readmissions and were assessed using the Pearson correlation coefficient (r). RESULTS: Of an estimated 86 024 patients meeting study criteria across 298 hospitals, 62.6% underwent CABG, 22.5% SAVR and 14.9% MVR. Unadjusted readmission rates following CABG, SAVR and MVR were 8.4%, 9.3% and 11.8%, respectively. Unadjusted MAE rates following CABG, SAVR and MVR were 35.1%, 32.3% and 37.0%, respectively. Following adjustment, interhospital differences accounted for 4.1% of explained variance in readmissions for CABG, 7.6% for SAVR and 10.0% for MVR. There was no association between readmission rates for CABG and SAVR (r=0.10, p=0.09) or SAVR and MVR (r=0.09, p=0.1). A weak association was noted between readmission rates for CABG and MVR (r=0.20, p<0.001). There was no significant association between readmission and MAE for CABG (r=0.06, p=0.2), SAVR (r=0.04, p=0.4) and MVR (r=-0.03, p=0.6). CONCLUSION: Our findings suggest that readmissions following adult cardiac surgery may not be an ideal quality measure as hospital factors do not appear to influence this outcome.

Left atrial appendage closure during cardiac surgery: Safe but underutilized in California.

Objective: Left atrial appendage (LAA) closure is associated with reduced rates of stroke in patients with atrial fibrillation (AF). We evaluated trends in LAA closure, the association of LAA closure with stroke/systemic embolism, and its safety profile in patients with AF who underwent cardiac surgery in California. We further tested for hospital-level variation in concomitant LAA closure. Methods: Adults who underwent coronary artery bypass grafting and/or valve surgery with preoperative AF were identified in the 2016 to 2019 Office of Statewide Health Planning and Development databases. Propensity score matching was performed to study risk-adjusted associations of LAA closure with ischemic stroke/systemic embolism. Hospital-level variation was studied using intraclass correlation coefficients. Results: Among 18,434 patients with AF who underwent coronary artery bypass grafting/valve surgery, 47.7% received LAA closure. Rates of LAA closure increased from 44.4% to 51.4% from 2016 to 2019 (P < .001). In 4652 propensity score-matched patients, LAA closure was associated with reduced incidence of stroke/systemic embolism at discharge (1.6% vs 3.1%; P < .001) and readmission with stroke/systemic embolism at 1 year (2.9% vs 4.5%; P = .004). LAA closure was not associated with acute kidney injury, pulmonary complications, blood transfusion, reoperation, or in-hospital mortality. Approximately 18% of the risk-adjusted variation in LAA use was attributed to the hospital, with median center-level rate of 44.9% (interquartile range, 29.6%-57.4%). Conclusions: LAA closure was associated with minimal surgical morbidity, and reduced short- and midterm incidence of stroke/systemic embolism. Although the use of LAA closure has increased, substantial variation exists among programs in California, suggesting the need for further standardization of care.

Center-Level Variation in Failure to Rescue After Elective Adult Cardiac Surgery.

BACKGROUND: There has been increasing emphasis on evaluation of failure to rescue (FTR) after major inpatient operations. The present study characterized center-level variation in FTR within a national cohort of patients undergoing elective cardiac operations. METHODS: All adults undergoing elective coronary artery bypass grafting and/or valve operations were identified in the 2016-2019 Nationwide Readmissions Database. FTR was defined as in-hospital death after prolonged mechanical ventilation, stroke, reoperation, acute kidney injury requiring dialysis, sepsis, cardiac arrest or pulmonary embolism. Multi-level, mixed-effects regressions were used to model mortality, complications, and FTR. Centers with high hospital-specific rates of FTR (≥95th percentile) were identified and compared to others. RESULTS: Of an estimated 454,506 patients included for analysis, 32,537 (7.2%) developed at least 1 complication, and 7669 (1.7%) died before discharge. Overall, 5370 (16.5%) patients experienced FTR. Compared with those who developed ≥1 complication but survived to discharge, FTR patients were significantly older, more commonly female, and had a greater burden of comorbidities as measured by the Elixhauser Comorbidity Index. Risk-adjusted, hospital-specific rates of mortality and FTR were moderately correlated (r = 0.64), mortality and complications were weakly associated (r = 0.16), and complications and FTR exhibited a very weak relationship (r = -0.02). Relative to others, centers with high rates of FTR had lower annual cardiac surgical volume (median 61 [interquartile range 33-133] vs 80 [interquartile range 43-149] cases/y, P = .019). CONCLUSIONS: The present findings affirm prior work demonstrating a close link between variation in FTR and mortality, but not complications. Further study is necessary to delineate modifiable care pathways that mitigate FTR.

National analysis of cost disparities in robotic-assisted versus laparoscopic abdominal operations.

BACKGROUND: Although the use of robotic-assisted surgery continues to expand, the cost-effectiveness of this platform remains unclear. The present study aimed to compare hospitalization costs and clinical outcomes between robotic-assisted surgery and laparoscopic approaches for major abdominal operations. METHODS: All adults receiving minimally invasive gastrectomy, cholecystectomy, colectomy (right, left, transverse, sigmoid), ventral hernia repair, hysterectomy, and abdominoperineal resection were identified in the 2012 to 2019 National Inpatient Sample. Records with concurrent operations were excluded. Multivariable linear and logistic regressions were developed to examine the association of the operative approach with costs, length of stay, and complications. An interaction term between the year and operative approach was used to analyze cost differences over time. RESULTS: Of an estimated 1,124,450 patients, 75.8% had laparoscopic surgery, and 24.2% had robotic-assisted surgery. Compared to laparoscopic, patients with robotic-assisted operations were younger and more commonly privately insured. The average hospitalization cost for laparoscopic cases was $16,000 ± 14,800 and robotic-assisted cases was $18,300 ± 13,900 (P < .001). Regardless of procedure type, all robotic-assisted operations had higher costs compared to laparoscopic operations. Risk-adjusted trend analysis revealed that the discrepancy in costs between laparoscopic and robotic-assisted surgery persisted and widened over time from $1,600 in 2012 to $2,600 in 2019. Compared to laparoscopic procedures, robotic procedures had a 2.2% reduction in complications (9.4 vs 11.6%, P < .001) and a 0.7-day decrement in the length of stay (95% confidence interval -0.8 to -0.7). CONCLUSION: Disparities in costs between robotic and laparoscopic abdominal operations have persisted over time. Given the modest decrement in adverse outcomes, further investigation into the clinical benefits of robotic surgery is warranted to justify its greater costs.

Impact of Pulmonary Complications on Outcomes and Resource Use After Elective Cardiac Surgery.

OBJECTIVE: To characterize the impact of pulmonary complications (PCs) on mortality, costs, and readmissions after elective cardiac operations in a national cohort and to test for hospital-level variation in PC. BACKGROUND: PC after cardiac surgery are targets for quality improvement efforts. Contemporary studies evaluating the impact of PC on outcomes are lacking, as is data regarding hospital-level variation in the incidence of PC. METHODS: Adults undergoing elective coronary artery bypass grafting and/or valve operations were identified in the 2016-2019 Nationwide Readmissions Database. PC was defined as a composite of reintubation, prolonged (>24 hours) ventilation, tracheostomy, or pneumonia. Generalized linear models were fit to evaluate associations between PC and outcomes. Institutional variation in PC was studied using observed-to-expected ratios. RESULTS: Of 588,480 patients meeting study criteria, 6.7% developed PC. After risk adjustment, PC was associated with increased odds of mortality (14.6, 95% CI, 12.6-14.8), as well as a 7.9-day (95% CI, 7.6-8.2) increase in length of stay and $41,300 (95% CI, 39,600-42,900) in attributable costs. PC was associated with 1.3-fold greater hazard of readmission and greater incident mortality at readmission (6.7% vs 1.9%, P <0.001). Significant hospital-level variation in PC was present, with observed-to-expected ratios ranging from 0.1 to 7.7. CONCLUSIONS: Pulmonary complications remain common after cardiac surgery and are associated with substantially increased mortality and expenditures. Significant hospital-level variation in PC exists in the United States, suggesting the need for systematic quality improvement efforts to reduce PC and their impact on outcomes.

Morbidity and Mortality Associated With Blood Transfusions in Elective Adult Cardiac Surgery.

OBJECTIVES: Perioperative transfusion thresholds have garnered increasing scrutiny as restrictive strategies have been shown to be noninferior. The study authors used data from a statewide academic collaborative to test the association between transfusion and 30-day mortality. DESIGN: All adult patients undergoing coronary artery bypass grafting (CABG) and/or valve surgeries between 2013 and 2019 in the authors' Academic Cardiac Surgery Consortium were examined. The relationship between the number of overall packed red blood cell (pRBC) and coagulation product (CP) (fresh frozen plasma, cryoprecipitate, platelets) transfusions on 30-day mortality was evaluated. Multivariate regression was used to evaluate predictors of transfusion and study endpoints. Machine learning (ML) models also were developed to predict 30-day mortality and rank transfusion-related features by relative importance. SETTING: At an Academic Cardiac Surgery Consortium of 5 institutions. PARTICIPANTS: Patients ≥18 years old undergoing CABG and/or valve surgeries. MEASUREMENTS AND MAIN RESULTS: Of the 7,762 patients (median hematocrit [HCT] 39%, IQR 35%-43%) who were included in the final study cohort, >40% were transfused at least 1 unit of pRBC or CP. In adjusted analyses, higher preoperative HCT was associated with reduced odds of mortality (adjusted odds ratio [aOR] 0.95, 95% CI 0.92-0.98), renal failure (aOR 0.95, 95% CI 0.92-0.98), and prolonged mechanical ventilation (aOR 0.97, 95% CI 0.95-0.99). In contrast, perioperative transfusions were associated with increased 30-day mortality after adjustment for preoperative HCT and other baseline features. The ML models were able to predict 30-day mortality with an area under the curve of 0.814-to-0.850, with perioperative transfusions displaying the highest feature importance. CONCLUSIONS: The present analysis found increasing HCT to be associated with a lower incidence of mortality. The study authors also found a direct dose-response association between transfusions and all study endpoints examined.

Transcatheter and Surgical Aortic Valve Replacement in Patients With Bicuspid Aortic Valve Stenosis.

BACKGROUND: Transcatheter aortic valve replacement (TAVR) is not widely used in patients with bicuspid aortic valve (BAV) disease and has not yet been studied in randomized clinical trials. We characterized the rate of use and outcomes of TAVR and surgical aortic valve replacement (SAVR) in patients with BAV. METHODS: Adults with BAV stenosis receiving SAVR or TAVR procedures were abstracted from the 2012 to 2019 Nationwide Readmissions Database (NRD). Risk-adjusted analyses were performed with NRD-provided weights and inverse probability of treatment weights (IPTW) to examine the association of treatment strategy on inpatient mortality, complications, and hospitalization resource utilization. Nonelective readmissions within 90 days of discharge and reintervention at the first readmission were also examined. RESULTS: Of an estimated 56 331 patients with BAV requiring aortic valve replacement, 6.8% underwent TAVR. Unadjusted analysis demonstrated higher index hospitalization mortality for TAVR compared with SAVR. Upon risk adjustment using NRD-provided weights, the odds of pacemaker implantation remained significantly higher for TAVR patients compared with SAVR, with no significant difference in mortality. When NRD-provided survey weights were applied, TAVR had higher rates of 90-day readmission. Adjustment with inverse probability of treatment weights resolved these differences between the 2 groups. Regardless of the risk-adjustment method, the odds of reintervention were consistently higher among BAV TAVR patients compared with SAVR. CONCLUSIONS: The present analysis demonstrates comparable in-hospital mortality and morbidity for TAVR and SAVR patients in the moderate-risk era. With increasing TAVR use in BAV, surgeons must further refine selection criteria with consideration of concomitant aortopathy and implications of reintervention.