A cost analysis of nonelective coronary artery bypass graft surgery

Machine learning prediction of hospitalization costs for coronary artery bypass grafting operations

BACKGROUND

With the steady rise in health care expenditures, the examination of factors that may influence the costs of care has garnered much attention. Although machine learning models have previously been applied in health economics, their application within cardiac surgery remains limited. We evaluated several machine learning algorithms to model hospitalization costs for coronary artery bypass grafting.

METHODS

All adult hospitalizations for isolated coronary artery bypass grafting were identified in the 2016 to 2020 Nationwide Readmissions Database. Machine learning models were trained to predict expenditures and compared with traditional linear regression. Given the significance of postoperative length of stay, we additionally developed models excluding postoperative length of stay to uncover other drivers of costs. To facilitate comparison, machine learning classification models were also trained to predict patients in the highest decile of costs. Significant factors associated with high cost were identified using SHapley Additive exPlanations beeswarm plots.

RESULTS

Among 444,740 hospitalizations included for analysis, the median cost of hospitalization in coronary artery bypass grafting patients was $43,103. eXtreme Gradient Boosting most accurately predicted hospitalization costs, with R2 = 0.519 over the validation set. The top predictive features in the eXtreme Gradient Boosting model included elective procedure status, prolonged mechanical ventilation, new-onset respiratory failure or myocardial infarction, and postoperative length of stay. After removing postoperative length of stay, eXtreme Gradient Boosting remained the most accurate model (R2 = 0.38). Prolonged ventilation, respiratory failure, and elective status remained important predictive parameters.

CONCLUSION

Machine learning models appear to accurately model total hospitalization costs for coronary artery bypass grafting. Future work is warranted to uncover other drivers of costs and improve the value of care in cardiac surgery.

Outcomes and Direct Cost of Isolated Nonemergent CABG in Patients With Low Ejection Fraction

OBJECTIVE

Preoperative left ventricular ejection fraction (LVEF) is one of the main predictors of outcomes in cardiac surgery. We present current era outcomes and associated direct cost in nonemergent isolated coronary artery bypass surgery (CABG) patients with LVEF <20% over the past 6 years and compare it with higher EF subgroups.

METHODS

Six-year data from 2016 to 2022 at hospitals sharing Society of Thoracic Surgeons and financial data with Biome Analytics were analyzed based on 3 EF subgroups (EF ≤20%, EF 21% to 35%, and EF >35%). Outcomes and costs were assessed.

RESULTS

Overall 30-day mortality of 12,649 patients was 1.9%. The EF ≤20% (n = 248), EF 21% to 35% (n = 1,408), and EF >35 (n = 10,993) cohorts had mortality of 6.9%, 3.7%, and 1.6%, respectively. The EF ≤20% subgroup had higher use of cardiopulmonary bypass, blood products, and mechanical support. In addition, the EF ≤20% subgroup had higher complication rates in almost all measured categories. Also, the EF ≤20% cohort had significantly higher length of stay, intensive care unit (ICU) hours, ICU and hospital readmissions, and lowest discharge to home rate. The strongest factors associated with mortality were postoperative cardiac arrest, renal failure requiring dialysis, extracorporeal membrane oxygenation, sepsis, prolonged ventilation, and gastrointestinal event. The overall median direct cost of care was $37,387.79 ($27,605.18, $51,720.96), with a median direct cost of care in the EF ≤20%, EF 21% to 35%, and EF >35% subgroups of $52,500.17 ($34,103.52, $80,806.79), $44,108.32 ($31,597.58, $63,788.03), and $36,521.80 ($27,168.91, $50,019.31), respectively.

CONCLUSIONS

In nonemergent isolated CABG surgery, low EF continues to have higher surgical risks and higher direct cost of care despite advances in cardiovascular care.

The timing of surgical revascularisation in acute myocardial infarction: when should we intervene?

INTRODUCTION

Coronary artery bypass grafting (CABG) is a crucial intervention in acute myocardial infarction (AMI), particularly when AMI is not amenable for management with primary percutaneous coronary intervention (PCI). To optimise outcome in these patients, surgical teams must consider a host of predictive factors, with the most prominent being the timing of CABG. Despite numerous studies exploring timing of CABG following AMI in the past, optimal surgical timing remains controversial. The mortality rates vary with timing of CABG, but confounding factors such as age, impaired pulmonary function, renal insufficiency, and poor left ventricular function may contribute to varied outcomes reported.

EVIDENCE ACQUISITON

An electronic literature search of articles that discussed acute myocardial presentation and urgent in-patient or elective CABG was conducted.

EVIDENCE SYNTHESIS

The evidence was synthesised based on each reported article and their outcomes.

CONCLUSIONS

Current literature suggests multiple factors can guide CABG timing including, type of AMI at initial presentation, distinctive pathological status and patient characteristics. Thus, there is a need for large, multi-centre studies to identify optimal CABG timing in complex coronary artery disease or failed PCI in patients with AMI. Future guidelines should emphasise patient cohorts by taking their risk factors into consideration. As such, a need for greater cardiac screening methods and development of scoring systems can aid in the optimisation of CABG timing.

CABG Improves Outcomes in Patients With Ischemic Cardiomyopathy: 10-Year Follow-Up of the STICH Trial

OBJECTIVES

The authors investigated the impact of coronary artery bypass grafting (CABG) on first and recurrent hospitalization in this population.

BACKGROUND

In the STICH (Surgical Treatment for Ischemic Heart Failure) trial, CABG reduced all-cause death and hospitalization in patients with and ischemic cardiomyopathy and left ventricular ejection fraction <35%.

METHODS

A total of 1,212 patients were randomized (610 to CABG + optimal medical therapy [CABG] and 602 to optimal medical therapy alone [MED] alone) and followed for a median of 9.8 years. All-cause and cause-specific hospitalizations were analyzed as time-to-first-event and as recurrent event analysis.

RESULTS

Of the 1,212 patients, 757 died (62.4%) and 732 (60.4%) were hospitalized at least once, for a total of 2,549 total all-cause hospitalizations. Most hospitalizations (66.2%) were for cardiovascular causes, of which approximately one-half (907 or 52.9%) were for heart failure. More than 70% of all hospitalizations (1,817 or 71.3%) were recurrent events. The CABG group experienced fewer all-cause hospitalizations in the time-to-first-event (349 CABG vs. 383 MED, adjusted hazard ratio [HR]: 0.85; 95% confidence interval [CI]: 0.74 to 0.98; p = 0.03) and in recurrent event analyses (1,199 CABG vs. 1,350 MED, HR: 0.78, 95% CI: 0.65 to 0.94; p < 0.001). This was driven by fewer total cardiovascular (CV) hospitalizations (744 vs. 968; p < 0.001, adjusted HR: 0.66, 95% CI: 0.55 to 0.81; p = 0.001), the majority of which were due to HF (395 vs. 512; p < 0.001, adjusted HR: 0.68, 95% CI: 0.52-0.89; p = 0.005). We did not observe a difference in non-CV events.

CONCLUSIONS

CABG reduces all-cause, CV, and HF hospitalizations in time-to-first-event and recurrent event analyses. (Comparison of Surgical and Medical Treatment for Congestive Heart Failure and Coronary Artery Disease [STICH]; NCT00023595).

The subsequent course of disability in older persons discharged to a skilled nursing facility after an acute hospitalization

OBJECTIVES

To evaluate the association between the type of acute hospitalization and subsequent course of disability in older persons discharged to a skilled nursing facility (SNF).

DESIGN

Longitudinal study of 754 community-living persons aged 70 or older.

PARTICIPANTS

The analytical sample included 365 participants who had one or more admissions to a SNF after an acute hospitalization (n=520 index admissions).

MEASUREMENTS

Information on hospitalizations, SNF admissions, and disability was ascertained over 15years. The primary and secondary outcomes were disability burden and recovery of pre-hospital function, respectively, assessed monthly over a 6-month period. Index admissions were classified into four mutually exclusive groups based on the type of hospitalization: elective major surgery, non-elective major surgery, critical illness, and other.

RESULTS

Disability worsened considerably after hospitalization for each of the four groups. Relative to elective major surgery, the disability burden over 6months was significantly greater for non-elective major surgery, critical illness, and other hospitalizations, with adjusted rate ratios (RRs) of 1.37 (95% CI 1.19 to 1.59), 1.37 (95% CI 1.19 to 1.58), and 1.29 (95% CI 1.14 to 1.47), respectively. Overall, recovery to pre-hospital function was observed in only 132 (25.4%) admissions. Relative to elective major surgery, the likelihood of recovering pre-hospital function was considerably lower for each of the three other groups. The results were consistent for basic, instrumental and mobility activities.

CONCLUSION

Among older persons discharged to a SNF after an acute hospitalization, the functional course over 6months was generally poor, with recovery to pre-hospital function observed in only one out of every four cases. Relative to elective major surgery, functional outcomes were worse for non-elective major surgery, critical illness, and other hospitalizations.

Incremental Cost of Emergency Versus Elective Surgery

OBJECTIVE

To determine hospital costs and the adjusted risk of death associated with emergent versus elective surgery.

BACKGROUND

Emergency surgery has a higher cost and worse outcomes compared with elective surgery. However, no national estimates of the excess burden of emergency surgery exist.

METHODS

Nationwide Inpatient Sample (NIS) data from 2001 to 2010 were analyzed. Patients aged 18 years or older who underwent abdominal aortic aneurysm repair, coronary artery bypass graft, or colon resection for neoplasm were included. Using generalized linear models with propensity scores, cost differences for emergent versus elective admission were calculated for each procedure. Multivariable logistic regression was performed to investigate the adjusted odds of mortality comparing elective and emergent cases. Discharge-level weights were applied to analyses.

RESULTS

A total of 621,925 patients, representing a weighted population of 3,057,443, were included. The adjusted mean cost difference for emergent versus elective care was $8741.22 (30% increase) for abdominal aortic aneurysm repair, $5309.78 (17% increase) for coronary artery bypass graft, and $7813.53 (53% increase) for colon resection. If 10% of the weighted estimates of emergency procedures had been performed electively, the cost benefit would have been nearly $1 billion, at $996,169,160 (95% confidence interval [CI], $985,505,565-$1,006,834,104). Elective surgery patients had significantly lower adjusted odds of mortality for all procedures.

CONCLUSIONS

Even a modest reduction in the proportion of emergent procedures for 3 conditions is estimated to save nearly $1 billion over 10 years. Preventing emergency surgery through improved care coordination and screening offers a tremendous opportunity to save lives and decrease costs.

Defining patients at high risk for gastrointestinal hemorrhage after drug-eluting stent placement: a cost utility analysis

INTRODUCTION

The study goal was to evaluate the cost-effectiveness of drug-eluting stent (DES) placement with consideration of gastrointestinal (GI) bleeding risk. DES reduce the need for future coronary revascularization, but require prolonged dual anti-platelet (DAT) therapy, which may increase the risk for GI bleeding. While DES have been found to be cost-effective in patients at average risk for GI bleeding, they may not be the most cost-effective strategy in higher risk patients.

METHODS

A Markov model was created to compare DES with bare metal stents (BMS). Patients were a hypothetical cohort of 60-year-old individuals with coronary artery stenosis that required nonemergent percutaneous coronary revascularization (PCI). The primary outcomes were the threshold incremental risks of GI bleeding from DAT based on willingness to pay (WTP) of $50,000, $100,000, and $150,000 per quality adjusted life year (QALY) gained.

RESULTS

For a WTP of $100,000, the relative risk of GI bleeding from DAT could be as high as 10.8 (when compared to aspirin alone) before DES would no longer be cost-effective. In patients with two risk factors for GI bleeding, the threshold relative risk could be as low as 1.6.

CONCLUSION

In average-risk patients, the risk of GI bleeding from DAT can be substantial without affecting the cost-effectiveness of DES. However, DES are unlikely to be cost-effective in patients with two or more risk factors for GI bleeding.

Clopidogrel in the management of acute coronary syndromes: indications, results, obstacles

Atherothrombosis is the underlying pathology of the acute coronary syndromes (ACS), in which platelet activation plays a key role. Therefore, antiplatelet therapy is an essential component of guideline-recommended ACS management. Considerable evidence clearly demonstrates the benefits of the antiplatelet agent clopidogrel in reducing mortality, decreasing recurrent cardiovascular events, and increasing arterial patency in ACS patients. Despite this evidence, data from patient registries and clinical initiatives such as CRUSADE (Can Rapid stratification of Unstable angina Suppress ADverse outcomes with Early implementation of the American College of Cardiology/American Heart Association guidelines) and GRACE (Global Registry of Acute Coronary Events) indicate that clopidogrel is underused in patients with ACS. This is especially true for patients receiving conservative medical management, many of whom have significant risk for recurrent ischemic events. The purpose of this review is to compare "real-life" clopidogrel therapy with evidence-based guidelines, and to highlight clinical factors that drive clopidogrel implementation or provide barriers to its use in ACS patients.

The use of the transition cost accounting system in health services research

The Transition cost accounting system integrates clinical, resource utilization, and financial information and is currently being used by several hospitals in Canada and the United States to calculate the costs of patient care. Our objectives were to review the use of hospital-based cost accounting systems to measure costs of treatment and discuss potential use of the Transition cost accounting system in health services research. Such systems provide internal reports to administrators for formulating major policies and strategic plans for future activities. Our review suggests that the Transition cost accounting information system may useful for estimating in-hospital costs of treatment.