Advancing Quality Metrics for Durable Left Ventricular Assist Device Implant: Analysis of the Society of Thoracic Surgeons Intermacs Database

BACKGROUND

Patients undergoing left ventricular assist device (LVAD) implantation are at risk for death and postoperative adverse outcomes. Interhospital variability and concordance of quality metrics were assessed using the Society of Thoracic Surgeons Interagency Registry for Mechanically Assisted Circulatory Support (Intermacs).

METHODS

A total of 22 173 patients underwent primary, durable LVAD implantation across 160 hospitals from 2012 to 2020, excluding hospitals performing <10 implant procedures. Observed and risk-adjusted operative mortality rates were calculated for each hospital. Outcomes included operative and 90-day mortality, a composite of adverse events (operative mortality, bleeding, stroke, device malfunction, renal dysfunction, respiratory failure), and secondarily failure to rescue. Rates are presented as median (interquartile range [IQR]). Hospital performance was evaluated using observed-to-expected (O/E) ratios for mortality and the composite outcome.

RESULTS

Interhospital variability existed in observed (median, 7.2% [IQR, 5.1%-9.6%]) mortality. The rates of adverse events varied across hospitals: major bleeding, 15.6% (IQR, 11.4%-22.4%); stroke, 3.1% (IQR, 1.6%-4.7%); device malfunction, 2.4% (IQR, 0.8%-3.7%); respiratory failure, 10.5% (IQR, 4.6%-15.7%); and renal dysfunction, 6.4% (IQR, 3.2%-9.6%). The O/E ratio for operative mortality varied from 0.0 to 6.1, whereas the O/E ratio for the composite outcome varied from 0.28 to 1.99. Hospital operative mortality O/E ratios were more closely correlated with the 90-day mortality O/E ratio (r = 0.74) than with the composite O/E ratio (r = 0.12).

CONCLUSIONS

This study reported substantial interhospital variability in performance for hospitals implanting durable LVADs. These findings support the need to (1) report hospital-level performance (mortality, composite) and (2) undertake benchmarking activities to reduce unwarranted variability in outcomes.

Area Deprivation and Medicare Spending for Coronary Artery Bypass Grafting: Insights from Michigan

BACKGROUND

Prior work has established that high socioeconomic deprivation is associated with worse short- and long-term outcomes for coronary artery bypass graft (CABG) patients. The relationship between socioeconomic status and 90-day episode spending is poorly understood. In this observational cohort analysis, we evaluated whether socioeconomically disadvantaged patients were associated with higher expenditures during 90-day episodes of care following isolated CABG.

METHODS

We linked clinical registry data from 8,728 isolated CABG procedures from January 1st, 2012 to December 31st, 2018 to Medicare fee-for-service claims data. Our primary exposure variable was patients in the top decile of the Area Deprivation Index. Linear regression was used to compare risk-adjusted, price-standardized 90-day episode spending for deprived against non-deprived patients, as well as component spending categories: index hospitalization, professional services, post-acute care, and readmissions.

RESULTS

A total of 872 patients were categorized as being in the top decile. Mean 90-day episode spending for the 8,728 patients in the sample was $55,258 (standard deviation = $26,252). Socioeconomically deprived patients had higher overall 90-day spending compared to non-deprived patients ($61,579 vs. $54,557, difference = $3,003, p = 0.001). Spending was higher in socioeconomically deprived patients for index hospitalizations (difference = $1,284, p = 0.005), professional services (difference = $379, p = 0.002) and readmissions (difference = $1,188, p = 0.008). Inpatient rehabilitation was the only significant difference in post-acute care spending (difference = $469, p = 0.011).

CONCLUSIONS

Medicare spending was higher for socioeconomically deprived CABG in Michigan, indicating systemic disparities over and above patient demographic factors.

Racial Disparities in Mitral Valve Surgery: A Statewide Analysis

OBJECTIVE

Racial disparities in health care have come to the forefront. We hypothesized that Black race was associated with worse preoperative risk, lower repair rates, and worse outcomes among patients who underwent mitral valve surgery.

METHODS

All patients who underwent mitral valve repair or replacement with or without coronary artery bypass grafting from 2011 to 2020 in a statewide collaborative database were stratified into 3 racial groups, White, Black, and other. Preoperative characteristics, procedure type, and outcomes were evaluated.

RESULTS

A total of 9074 mitral valve operations were performed at 33 centers (Black 1009 [11.1%], White 7862 [86.6%]). Preoperative combined Society of Thoracic Surgeons morbidity and mortality was higher for Black patients (Black 32%, White 22%, other 23%, [P < .001]) because of a greater proportion of diabetes, hypertension, and chronic lung disease. White patients were more likely to undergo mitral repair (White 66%, Black 53.3%, other 57%; P < .001). Operative mortality was similar across racial groups (White 3.7%, Black 4.6%, other 4.5%; P = .36). After adjusting for preoperative factors, mitral etiology, and hospitals, race was not associated with mitral valve repair, complications, or mortality, but Black patients had higher odds of extended care facility utilization and readmission.

CONCLUSIONS

Contrary to our hypothesis, there was no difference in the odds of repair or operative mortality across races after accounting for risk and etiology. However, Black patients were more likely to be readmitted after discharge. These findings support a greater focus on reducing disparities in mitral valve surgery.

Hospital and Operator Variation in Cardiac Rehabilitation Referral and Participation After Percutaneous Coronary Intervention: Insights From Blue Cross Blue Shield of Michigan Cardiovascular Consortium

BACKGROUND

Despite its established benefit and strong endorsement in international guidelines, cardiac rehabilitation (CR) use remains low. Identifying determinants of CR referral and use may help develop targeted policies and quality improvement efforts. We evaluated the variation in CR referral and use across percutaneous coronary intervention (PCI) hospitals and operators.

METHODS

We performed a retrospective observational cohort study of all patients who underwent PCI at 48 nonfederal Michigan hospitals between January 1, 2012 and March 31, 2018 and who had their PCI clinical registry record linked to administrative claims data. The primary outcomes included in-hospital CR referral and CR participation, defined as at least one outpatient CR visit within 90 days of discharge. Bayesian hierarchical regression models were fit to evaluate the association between PCI hospital and operator with CR referral and use after adjusting for patient characteristics.

RESULTS

Among 54 217 patients who underwent PCI, 76.3% received an in-hospital referral for CR, and 27.1% attended CR within 90 days after discharge. There was significant hospital and operator level variation in in-hospital CR referral with median odds ratios of 3.88 (95% credible interval [CI], 3.06-5.42) and 1.64 (95% CI, 1.55-1.75), respectively, and in CR participation with median odds ratios of 1.83 (95% CI, 1.63-2.15) and 1.40 (95% CI, 1.35-1.47), respectively. In-hospital CR referral was significantly associated with an increased likelihood of CR participation (adjusted odds ratio, 1.75 [95% CI, 1.52-2.01]), and this association varied by treating PCI hospital (odds ratio range, 0.92-3.75) and operator (odds ratio range, 1.26-2.82).

CONCLUSIONS

In-hospital CR referral and 90-day CR use after PCI varied significantly by hospital and operator. The association of in-hospital CR referral with downstream CR use also varied across hospitals and less so across operators suggesting that specific hospitals and operators may more effectively translate CR referrals into downstream use. Understanding the factors that explain this variation will be critical to developing strategies to improve CR participation overall.

Center Variability in Medicare Claims-Based Publicly Reported Transcatheter Aortic Valve Replacement Outcome Measures

Background

Public reporting of transcatheter aortic valve replacement (TAVR) claims–based outcome measures is used to identify high‐ and low‐performing centers. Whether claims‐based TAVR outcomes can reliably be used for center‐level comparisons is unknown. In this study, we sought to evaluate center variability in claims‐based TAVR outcomes used in public reporting.

Methods and Results

The study sample included 119 554 Medicare beneficiaries undergoing TAVR between January 2014 and October 2018 based on procedure codes in 100% Medicare inpatient claims. Multivariable hierarchical logistic regression was used to estimate center‐specific adjusted rates and reliability (R) of 30‐day mortality, discharge not to home/self‐care, 30‐day stroke, and 30‐day readmission. Reliability was defined as the ratio of between‐hospital variation to the sum of the between‐ and within‐hospital variation. The median (interquartile range [IQR]) center‐level adjusted outcome rates were 3.1% (2.9%–3.4%) for 30‐day mortality, 41.4% (31.3%–53.4%) for discharge not to home, 2.5% (2.3%–2.7%) for 30‐day stroke, and 14.9% (14.4%–15.5%) for 30‐day readmission. Median reliability was highest for the discharge not to home measure (R=0.95; IQR, 0.94–0.97), followed by the 30‐day stroke (R=0.92; IQR, 0.87–0.94), 30‐day mortality (R=0.86; IQR, 0.81–0.91), and 30‐day readmission measures (R=0.42; IQR, 0.35–0.51). Across outcomes, there was an inverse relationship between center volume and measure reliability.

Conclusions

Claims‐based TAVR outcome measures for mortality, discharge not to home, and stroke were reliable measures for center‐level comparisons, but readmission measures were unreliable. Stakeholders should consider these findings when evaluating claims‐based measures to compare center‐level TAVR performance.

Generalizability of Trial Data to Real-World Practice: An Analysis of The Society of Thoracic Surgeons Intermacs Database

BACKGROUND

While the current wide-scale adoption of the HeartMate 3 left ventricular assist device (LVAD) can be attributed to favorable clinical trial outcomes, restrictive clinical trial eligibility criteria may result in lack of generalizability to real-world populations. We assessed the generalizability of LVAD clinical trial outcomes and evaluated the prognostic value of specific inclusion/exclusion criteria.

METHODS

MOMENTUM 3 (Multicenter Study of MagLev Technology in Patients Undergoing Mechanical Circulatory Therapy with HeartMate 3) eligibility criteria were applied to patients identified in The Society of Thoracic Surgeons Interagency Registry for Mechanically Assisted Circulatory Support who underwent HeartMate 3 implantation [n=4610] between August 2017-March 2020. Patients were categorized as trial-eligible or trial-ineligible and by number of ineligibility criteria. The effect of trial eligibility on mortality was estimated using Cox models.

RESULTS

Indications for HeartMate 3 implant included destination therapy (n=2827, 61%), bridge-to-candidacy (n=969, 21%), and bridge-to-transplant (n=702, 15%). A total of 1941 (42%) recipients were trial-ineligible, with 1245 (27%) meeting 1 ineligibility criterion, 470 (10%) meeting 2, and 226 (5%) meeting ≥3. Estimated 1-year mortality for trial-ineligible recipients was higher than for trial-eligible recipients (17±1% vs. 10±1%, p<0.001). Compared with trial-eligible patients, 1-year mortality was incrementally higher for patients meeting 1 (15±1%), 2 (16±2%), and ≥3 (30±3%) ineligibility criteria. Thrombocytopenia and elevated creatinine, bilirubin, and international normalized ratio in trial-ineligible patients were independently associated with increased mortality.

CONCLUSIONS

Despite differences in mortality, both trial-eligible and trial-ineligible HeartMate 3 recipients had excellent outcomes in real-world practice, suggesting future trial eligibility criteria could be expanded.

A challenge to equity in transplantation: Increased center-level variation in short-term mechanical circulatory support use in the context of the updated U.S. heart transplant allocation policy

BACKGROUND

The United States National Organ Procurement Transplant Network (OPTN) implemented changes to the adult heart allocation system to reduce waitlist mortality by improving access for those at greater risk of pre-transplant death, including patients on short-term mechanical circulatory support (sMCS). While sMCS increased, it is unknown whether the increase occurred equitably across centers.

METHODS

The OPTN database was used to assess changes in use of sMCS at time of transplant in the 12 months before (pre-change) and after (post-change) implementation of the allocation system in October 2018 among 5,477 heart transplant recipients. An interrupted time series analysis comparing use of bridging therapies pre- and post-change was performed. Variability in the proportion of sMCS use at the center level pre- and post-change was determined.

RESULTS

In the month pre-change, 9.7% of patients were transplanted with sMCS. There was an immediate increase in sMCS transplant the following month to 32.4% - an absolute and relative increase of 22.7% and 312% (p < 0.001). While sMCS use was stable pre-change (monthly change 0.0%, 95% CI [-0.1%,0.1%]), there was a continuous 1.2%/month increase post-change ([0.6%,1.8%], p < 0.001). Center-level variation in sMCS use increased substantially after implementation, from a median (interquartile range) of 3.85% (10%) pre-change to 35.7% (30.6%) post-change (p < 0.001).

CONCLUSIONS

Use of sMCS at time of transplant increased immediately and continued to expand following heart allocation policy changes. Center-level variation in use of sMCS at the time of transplant increased compared to pre-change, which may have negatively impacted equitable access to heart transplantation.

Evaluating treatment-specific post-discharge quality-of-life and cost-effectiveness of TAVR and SAVR: Current practice & future directions

•

Post-TAVR HRQOL shows more rapid short-term improvement than SAVR within trials.

•

Higher TAVR use requires better real-world TAVR/SAVR cost-effectiveness comparisons.

•

Wearable devices should be used in real-world settings to compare TAVR/SAVR HRQOL.

Background

Aortic stenosis is a prevalent valvular heart disease that is treated primarily by surgical aortic valve replacement (SAVR) or transcatheter aortic valve replacement (TAVR), which are common treatments for addressing symptoms secondary to valvular heart disease. This narrative review article focuses on the existing literature comparing recovery and cost-effectiveness for SAVR and TAVR.

Methods

Major databases were searched for relevant literature discussing HRQOL and cost-effectiveness of TAVR and SAVR. We also searched for studies analyzing the use of wearable devices to monitor post-discharge recovery patterns.

Results

The literature focusing on quality-of-life following TAVR and SAVR has been limited primarily to single-center observational studies and randomized controlled trials. Studies focused on TAVR report consistent and rapid improvement relative to baseline status. Common HRQOL instruments (SF-36, EQ-5D, KCCQ, MLHFQ) have been used to document that TF-TAVR is advantageous over SAVR at 1-month follow-up, with the benefits leveling off following 1 year. TF-TAVR is economically favorable relative to SAVR, with estimated incremental cost-effectiveness ratio values ranging from $50,000 to $63,000/QALY gained. TA-TAVR has not been reported to be advantageous from an HRQOL or cost-effectiveness perspective.

Conclusions

While real-world experiences are less described, large-scale trials have advanced our understanding of recovery and cost-effectiveness of aortic valve replacement treatment strategies. Future work should focus on scalable wearable device technology, such as smartwatches and heart-rate monitors, to facilitate real-world evaluation of TAVR and SAVR to support clinical decision-making and outcomes ascertainment.

High Socioeconomic Deprivation and Coronary Artery Bypass Grafting Outcomes: Insights from Michigan

BACKGROUND

Cardiovascular outcomes are worse among individuals from areas with limited socioeconomic resources. This study evaluated the relationship between high socioeconomic deprivation and isolated coronary artery bypass grafting (CABG) outcomes.

METHODS

We linked statewide Society of Thoracic Surgeons Adult Cardiac Surgery Database data to Medicare fee-for-service records for 10,423 Michigan residents undergoing isolated CABG between 01/2012-12/2018. High socioeconomic deprivation was defined as residing in the highest decile of zip code-level area deprivation index (ADI). Multivariable logistic regression estimated the relationship between top ADI decile and major morbidity, in-hospital mortality, and operative mortality. Survival analyses evaluated long-term survival comparing patients in the top versus not in the top ADI decile.

RESULTS

A total of 1,036 patients were in the top decile of ADI (ADI>82.4), and were more likely to be female, black, and have a higher predicted risk of mortality. Patients in the top ADI decile had significantly higher rates of major morbidity (17.4% versus 11.4%, adjusted odds ratio =1.26, 95% CI: 1.04-1.54, p=0.021) and in-hospital mortality (3.2% versus 1.3%, adjusted odds ratio=1.84, 95% CI: 1.18-2.86, p=0.007), but not operative mortality. The adjusted hazard of mortality was 16% higher for patients residing in the top ADI decile (95% CI: 1.01-1.33, p=0.032).

CONCLUSIONS

Isolated CABG patients residing in the highest areas of socioeconomic deprivation differed with respect to demographic and clinical characteristics, and experienced worse short and long-term outcomes compared with those not in the top ADI decile.

Determinants of Hospital Variation in Cardiac Rehabilitation Enrollment During Coronary Artery Disease Episodes of Care

BACKGROUND

Cardiac rehabilitation (CR) is associated with improved outcomes for patients with coronary artery disease (CAD). However, CR enrollment remains low and there is a dearth of real-world data on hospital-level variation in CR enrollment. We sought to explore determinants of hospital variability in CR enrollment during CAD episodes of care: medical management of acute myocardial infarction (AMI-MM), percutaneous coronary intervention (PCI), and coronary artery bypass grafting (CABG).

METHODS

A cohort of 71 703 CAD episodes of care were identified from 33 hospitals in the Michigan Value Collaborative statewide multipayer registry (2015 to 2018). CR enrollment was defined using professional and facility claims and compared across treatment strategies: AMI-MM (n=18 678), PCI (n=41 986), and CABG (n=11 039). Hierarchical logistic regression was used to estimate effects of predictors and hospital risk-adjusted rates of CR enrollment.

RESULTS

Overall, 20 613 (28.8%) patients enrolled in CR, with significant differences by treatment strategy: AMI-MM=13.4%, PCI=29.0%, CABG=53.8% (P<0.001). There were significant differences in CR enrollment across age groups, comorbidity status, and payer status. At the hospital-level, there was over 5-fold variation in hospital risk-adjusted CR enrollment rates (9.8%-51.6%). Hospital-level CR enrollment rates were highly correlated across treatment strategy, with the strongest correlation between AMI-MM versus PCI (R²=0.72), followed by PCI versus CABG (R²=0.51) and AMI-MM versus CABG (R²=0.46, all P<0.001).

CONCLUSIONS

Substantial variation exists in CR enrollment during CAD episodes of care across hospitals. However, within-hospital CR enrollment rates were significantly correlated across all treatment strategies. These findings suggest that CR enrollment during CAD episodes of care is the product of hospital-specific rather than treatment-specific practice patterns.

Assessment of Mortality Among Durable Left Ventricular Assist Device Recipients Ineligible for Clinical Trials

Importance

While wide-scale adoption of durable left ventricular assist devices (LVADs) can be attributed to favorable randomized clinical trial outcomes, restrictive selection criteria may be associated with a lack of generalizability to real-world experience.

Objective

To estimate the proportion of LVAD recipients who are eligible for clinical trials and to assess whether an association exists between trial eligibility and mortality.

Design, Setting, and Participants

This cohort study examined 14 679 patients undergoing primary, intracorporeal continuous-flow LVAD implantation (with or without a right ventricular assist device) in 181 North American centers from January 1, 2012, to June 30, 2017, identified in the Interagency Registry for Mechanically Assisted Circulatory Support (INTERMACS). To simulate a trial population, trial criteria from the Multicenter Study of MagLev Technology in Patients Undergoing Mechanical Circulatory Therapy With HeartMate 3 (MOMENTUM 3) were mapped to INTERMACS variables. Patients were categorized as eligible for trial inclusion or ineligible for trial inclusion and by number of ineligibility criteria met. Follow-up in INTERMACS was complete for all patients through October 31, 2017. Data were analyzed from July 2019 through November 2020.

Exposures

Undergoing durable LVAD implantation.

Main Outcomes and Measures

Trial eligibility and postimplant mortality were analyzed using Kaplan-Meier estimates and Cox proportional hazards models.

Results

Among 14 679 recipients, mean (SD) age was 57 (13) years, 11 503 individuals (78.4%) were men, and 11 406 individuals (77.7%) presented with New York Heart Association class IV heart failure. A total of 6429 recipients (43.8%) were ineligible for trial inclusion, of whom 4226 individuals (65.7%) met 1 ineligibility criterion, 1442 individuals (22.4%) met 2 criteria, and 761 individuals (11.8%) met 3 or more criteria. Estimated mortality for recipients who were trial-ineligible was higher than for recipients who were trial-eligible (1-year mortality: 25.3% [95% CI, 24.2%-26.5%] vs 16.2% [95% CI, 15.4%-17.1%]; 3-year mortality: 42.8% [95% CI, 41.3%-44.4%] vs 36.4% [95% CI, 35.0%-37.8%]; log-rank P < .001 for both). Patients who were trial-ineligible had increased risk of mortality compared with patients who were trial-eligible if they met 1 trial ineligibility criterion (hazard ratio [HR], 1.16 [95% CI, 1.08-1.24]; P < .001), 2 trial ineligibility criteria (HR, 1.51 [95% CI, 1.36-1.67]; P < .001), or 3 or more trial ineligibility criteria (HR, 2.09 [95% CI, 1.84-2.39]; P < .001). Among patients meeting only 1 ineligibility criterion, 4 criteria were independently associated with mortality: prior or ongoing mechanical circulatory support (HR, 1.63 [95% CI, 1.23-2.16]; P = .001), elevated creatinine level (HR, 1.42 [95% CI, 1.17-1.72]; P < .001), elevated bilirubin level (HR, 1.39 [95% CI, 1.17-1.66]; P < .001), and low albumin or prealbumin level (HR, 1.18 [95% CI, 1.05-1.33]; P = .007).

Conclusions and Relevance

These findings suggest that while treatment for patients who are ineligible for LVAD trial inclusion should be weighed against medical management, more consideration could be given to designing trials with eligibility criteria that reflect real-world experience.

Determinants of Value in Coronary Artery Bypass Grafting

Background Over 180 000 coronary artery bypass grafting (CABG) procedures are performed annually, accounting for $7 to $10 billion in episode expenditures. Assessing tradeoffs between spending and quality contributing to value during 90-day episodes has not been conducted but is essential for success in bundled reimbursement models. We, therefore, identified determinants of variability in hospital 90-day episode value for CABG. Methods Medicare and private payor admissions for isolated CABG from 2014 to 2016 were retrospectively linked to clinical registry data for 33 nonfederal hospitals in Michigan. Hospital composite risk-adjusted complication rates (≥1 National Quality Forum-endorsed, Society of Thoracic Surgeons measure: deep sternal wound infection, renal failure, prolonged ventilation >24 hours, stroke, re-exploration, and operative mortality) and 90-day risk-adjusted, price-standardized episode payments were used to categorize hospitals by value by defining the intersection between complications and spending. Results Among 2573 total patients, those at low- versus high-value hospitals had a higher percentage of prolonged length of stay >14 days (9.3% versus 2.4%, P=0.006), prolonged ventilation (17.6% versus 4.8%, P<0.001), and operative mortality (4.8% versus 0.6%, P=0.001). Mean total episode payments were $51 509 at low-compared with $45 526 at high-value hospitals (P<0.001), driven by higher readmission ($3675 versus $2177, P=0.005), professional ($7462 versus $6090, P<0.001), postacute care ($7315 versus $5947, P=0.031), and index hospitalization payments ($33 474 versus $30 800, P<0.001). Among patients not experiencing a complication or 30-day readmission (1923/2573, 74.7%), low-value hospitals had higher inpatient evaluation and management payments ($1405 versus $752, P<0.001) and higher utilization of inpatient rehabilitation (7% versus 2%, P<0.001), but lower utilization of home health (66% versus 73%, P=0.016) and emergency department services (13% versus 17%, P=0.034). Conclusions To succeed in emerging bundled reimbursement programs for CABG, hospitals and physicians should identify strategies to minimize complications while optimizing inpatient evaluation and management spending and use of inpatient rehabilitation, home health, and emergency department services.

Sources of Hospital Variation in Postacute Care Spending After Cardiac Surgery

BACKGROUND

Postacute care is a major driver of cardiac surgical episode spending, but the sources of variation in spending have not been explored. The objective of this study was to identify sources of variation in postacute care spending within 90-days of discharge following coronary artery bypass grafting (CABG) and aortic valve replacement (AVR) and the relationship between postacute care spending and other postdischarge utilization.

METHODS AND RESULTS

A retrospective analysis was conducted of public and private administrative claims for Michigan residents insured by Medicare fee-for-service and Blue Cross Blue Shield of Michigan/Blue Care Network commercial and Medicare Advantage plans undergoing CABG (n=11 208) or AVR (n=6122) in 33 nonfederal acute care Michigan hospitals between January 1, 2015 and December 31, 2018. Postacute care use was present in 9662 (86.2%) CABG episodes and 4242 (69.3%) AVR episodes, with respective mean (SD) 90-day spending of $4398±$6124 and $3465±$5759. Across hospitals, mean postacute care spending ranged from $3280 to $8186 for CABG and $2246 to $7710 for AVR. Inpatient rehabilitation and skilled nursing facility care accounted for over 80% of the variation spending between low and high postacute care spending hospitals. At the hospital-level, postacute care spending was modestly correlated across procedures and payers. Spending associated with readmissions, emergency department visits, and outpatient facility care was significantly different between low and high postacute care spending hospitals in CABG and AVR episodes.

CONCLUSIONS

There was wide hospital variation in postacute care spending after cardiac surgery, which was primarily driven by differential use and intensity in facility-based postacute care. Optimizing facility-based postacute care after cardiac surgery offers unique opportunities to reduce potentially unwarranted care variation.

Evaluating the Impact of Pneumonia Prevention Recommendations After Cardiac Surgery

BACKGROUND

Pneumonia is the most prevalent healthcare-associated infection after coronary artery bypass grafting (CABG), but the relative effectiveness of strategies to reduce its incidence remains unclear. We evaluated the relationship between healthcare-associated infection recommendations and risk of pneumonia after CABG.

METHODS

Pneumonia prevention practice recommendations were developed based on literature review and analysis of semistructured interviews with key health care personnel across centers with low (<5.9%), medium (5.9%-6.1%), and high (>6.1%) rates of pneumonia. These practices were implemented among 2482 patients undergoing CABG from 2016 to 2017 across 18 centers. The independent effect of each practice in reducing pneumonia was assessed using multivariable logistic regression, adjusting for baseline risk and center. A composite (bundle) score was calculated as the number of practices (0 to 4) each patient received.

RESULTS

Recommended pneumonia prevention practices included lung protective ventilation management, early extubation, progressive ambulation, and avoidance of postoperative bronchodilator therapy. Pneumonia occurred in 2.4% of patients. Lung protective ventilation (adjusted odds ratio [ORadj], 0.45; 95% confidence interval [CI], 0.22-0.92), ambulation (ORadj, 0.08; 95% CI, 0.04-0.17), and postoperative ventilation of less than 6 hours (ORadj, 0.47; 95% CI, 0.26-0.87) were significantly associated with lower odds of pneumonia. Postoperative bronchodilator therapy (ORadj, 4.83; 95% CI, 2.20-10.7) was significantly associated with higher odds. Risk-adjusted rates of pneumonia, operative mortality, and intensive care unit length of stay were lower in patients with higher bundle scores (all P-trend < .01).

CONCLUSIONS

These pneumonia prevention recommendations may serve as effective targets for avoiding postoperative healthcare-associated infections.

Determinants of hospital variability in perioperative red blood cell transfusions during coronary artery bypass graft surgery

OBJECTIVE

To identify to what extent distinguishing patient and procedural characteristics can explain center-level transfusion variation during coronary artery bypass grafting surgery.

METHODS

Observational cohort study using the Perfusion Measures and Outcomes Registry from 43 adult cardiac surgical programs from July 1, 2011, to July 1, 2017. Iterative multilevel logistic regression models were constructed using patient demographic characteristics, preoperative risk factors, and intraoperative conservation strategies to progressively explain center-level transfusion variation.

RESULTS

Of the 22,272 adult patients undergoing isolated coronary artery bypass surgery using cardiopulmonary bypass, 7241 (32.5%) received at least 1 U allogeneic red blood cells (range, 10.9%-59.9%). When compared with patients who were not transfused, patients who received at least 1 U red blood cells were older (68 vs 64 years; P < .001), were women (41.5% vs 15.9%; P < .001), and had a lower body surface area (1.93 m² vs 2.07 m²; P < .001), respectively. Among the models explaining center-level transfusion variability, the intraclass correlation coefficients were 0.07 for model 1 (random intercepts), 0.12 for model 2 (patient factors), 0.14 for model 3 (intraoperative factors), and 0.11 for model 4 (combined). The coefficient of variation for center-level transfusion rates were 0.31, 0.29, 0.40, and 0.30 for models 1 through 4, respectively. The majority of center-level variation could not be explained through models containing both patient and intraoperative factors.

CONCLUSIONS

The results suggest that variation in center-level red blood cells transfusion cannot be explained by patient and procedural factors alone. Investigating organizational culture and programmatic infrastructure may be necessary to better understand variation in transfusion practices.

The Effect of Hospital Market Competition on the Adoption of Transcatheter Aortic Valve Replacement

BACKGROUND

The use of transcatheter aortic valve replacement (TAVR) has grown rapidly. The purpose of this study was to assess whether hospital market competition was associated with the use of TAVR.

METHODS

We used 5 Healthcare Cost and Utilization Project state inpatient databases (Arizona, Florida, Iowa, Massachusetts, Washington) to identify patients undergoing TAVR (n = 5563) or surgical aortic valve replacement (n = 30,672) across 154 hospitals from 2011 to 2014. Using the Herfindahl-Hirschman Index (HHI) to calculate market competition, hospitals were categorized into commonly used categories of low (HHI >0.25), moderate (HHI 0.15-0.25), and high (HHI <0.15) competition. We associated market competition category with TAVR utilization using hierarchical logistic regression, adjusting for patient characteristics, hospital characteristics, year, and hospital random effect. We modeled associations between HHI category and in-hospital mortality, admission length of stay, and discharge to home as secondary outcomes.

RESULTS

After adjustment, patients treated at high-competition hospitals had higher odds of receiving TAVR, relative to patients at low-competition hospitals (adjusted odds ratio [ORadj], 5.31; 95% confidence interval [CI], 2.10-13.4). TAVR use increased each year (ORadj, 1.73; 95% CI, 1.38-2.17) but was similar across HHI categories. Competition was not associated with in-hospital mortality or length of stay. Patients at high-competition hospitals were more likely to be discharged home (ORadj, 2.39; 95% CI, 1.23-4.66) compared with patients at low-competition hospitals.

CONCLUSIONS

Market competition was positively associated with a hospital's adoption of TAVR. Future studies should further examine the impact of competition on quality and appropriateness.

Episode Payments for Transcatheter and Surgical Aortic Valve Replacement

BACKGROUND

Aortic stenosis is the most common valvular heart disease in the United States. Transcatheter aortic valve replacement (TAVR) is increasingly being adopted as an alternative to surgical aortic valve replacement (SAVR). In an era of value-based payment reform, our objective was to better understand the economic impact of the use of TAVR and SAVR in the United States.

METHODS AND RESULTS

We performed a retrospective cohort study of Medicare beneficiaries who underwent TAVR or SAVR between 2012 and 2015. Using claims from a 20% sample of national fee-for-service Medicare beneficiaries, we calculated episode payments for patients who underwent aortic valve replacement from 90 days before aortic valve replacement through 90 days after hospital discharge. Among 18 804 eligible patients, 6455 underwent TAVR (34.3%), and 12 349 underwent SAVR (65.7%). After adjustment for patient characteristics, episode payments for TAVR were ≈7% lower than for SAVR (TAVR, $55 545 [95% CI, $54 643-56 446] versus $59 467 [95% CI, $58 723-60 211]; P<0.001). Patients with TAVR had higher preprocedural payments, but lower payments during and after the index hospitalization for the procedure. Episode payments increased with increasing comorbidity score for patients undergoing TAVR or SAVR (rate ratio, 1.16 [95% CI, 1.15-1.17]; P<0.001); however, this association was stronger for SAVR (rate ratio, 1.18 [95% CI, 1.17-1.19]) than for TAVR (rate ratio, 1.11 [95% CI, 1.11-1.12]; P<0.001 for interaction). Thus, differences in episode payments between TAVR and SAVR were greatest for the sickest patients but much less in healthier patients.

CONCLUSIONS

TAVR is associated with lower episode payments than SAVR. However, episode payments for TAVR are less influenced by patient comorbidity. Therefore, as TAVR is increasingly used in patients with better baseline health status, the economic advantages of TAVR relative to SAVR may diminish.

Impact of Missing Stroke Severity Data on the Accuracy of Hospital Ischemic Stroke Mortality Profiling

BACKGROUND

The Centers for Medicare and Medicaid Services have proposed 30-day ischemic stroke risk-standardized mortality rates that include adjustment for stroke severity using the National Institute of Health Stroke Scale (NIHSS), which is often undocumented. We used simulations to quantify the effect of missing NIHSS data on the accuracy of hospital-level ischemic stroke risk-standardized mortality rate profiling for 100 hypothetical hospitals with different case volumes.

METHODS AND RESULTS

We generated simulated data sets of patients with NIHSS scores and other predictors of 30-day mortality based on empirical analysis of data from 7654 patients with ischemic stroke in the Michigan Stroke Registry. We assigned and rank-ordered a true (known) 30-day mortality rate to each hospital in the simulated data sets of N=100 hospitals with either low (100 patients with stroke), medium (300), or high (500) case volumes. We then estimated and rank-ordered 30-day risk-standardized mortality rates for the N=100 hospitals in each simulated data set using hierarchical logistic regression models. In each data set, we systematically varied the rate of missing NIHSS data and whether missing NIHSS data was independent (missing completely at random) or dependent (missing not at random) on the NIHSS score. With no missing NIHSS data, the Spearman correlation between the true hospital performance rank order assigned during data set generation and the estimated 30-day risk-standardized mortality rate rank order was 0.72, 0.88, and 0.91 in low, medium, and high volume hospitals, respectively. However, this fell to as low as 0.50, 0.71, and 0.79 as missing NIHSS data reached 70%.

CONCLUSIONS

Missing NIHSS data had substantial detrimental effects on the accuracy of profiling of ischemic stroke mortality, especially in lower volume hospitals. Even with complete NIHSS documentation, significant limitations in ischemic stroke mortality profiling remain.

Association Between Postoperative Pneumonia and 90-Day Episode Payments and Outcomes Among Medicare Beneficiaries Undergoing Cardiac Surgery

Background Postoperative pneumonia is the most common healthcare-associated infection in cardiac surgical patients, yet their impact across a 90-day episode of care remains unknown. Our objective was to examine the relationship between pneumonia and 90-day episode payments and outcomes among Medicare beneficiaries undergoing cardiac surgery. Methods and Results Medicare claims were used to identify beneficiaries with episodes of coronary artery bypass grafting (CABG; n=56 728) and valve surgery (n=56 377) across 1045 centers between April 2014 and March 2015. Using a published diagnosis code-based algorithm, we identified pneumonia in 6.4% CABG episodes and 6.6% of valve surgery episodes. We compared price-standardized 90-day episode payments and outcome measures (postoperative length of stay, discharge to postacute care, mortality, and readmission) between beneficiaries with and without pneumonia using hierarchical regression models, adjusting for patient factors and hospital random effects. Pneumonia was associated with 24.5% higher episode payments for CABG ($46 723 versus $37 496; P<0.001) and 26.5% higher episode payments for valve surgery ($61 544 versus $48 549; P<0.001). For both cohorts, pneumonia was significantly associated with longer postoperative length of stay (CABG: +4.1 days, valve: +5.6 days), more frequent discharge to postacute care (CABG: odds ratio [OR]=1.99, valve: OR=2.17), and higher rates of 30-day mortality (CABG: OR=2.42, valve: OR=2.57) and 90-day readmission (CABG: OR=1.20, valve: OR=1.25), all P<0.001. We compared episode payments and outcomes across terciles of pneumonia rates and found that high pneumonia rate hospitals had higher episode payments and poorer outcomes compared with episodes at low pneumonia rate hospitals in both CABG and valve surgery cohorts. Conclusions Postoperative pneumonia was associated with significantly higher 90-day episode payments and inferior outcomes at the patient and hospital level. Future work should examine whether reducing pneumonia after cardiac surgery reduces episode spending and improves outcomes, which could facilitate hospital success in value-based reimbursement programs.

Volume-Outcome Relationships in Surgical and Endovascular Repair of Aortic Dissection

BACKGROUND

As surgical mortality decreases and endovascular utilization increases, it is unknown whether volume-outcome relationships exist in thoracic aortic dissection repair. We characterized volume-outcome relationships for surgical and endovascular management of thoracic aortic dissection.

METHODS

Patients aged more than 18 years undergoing repair of thoracic aortic dissection in the United States between 2010 and 2014 were identified in seven all-payer state inpatient administrative databases. Patients were divided into groups based on type of repair: surgical repair of type A dissection (TAAD), surgical repair of type B dissection (TBAD), and endovascular repair (TEVAR). Hierarchical logistic regression models evaluated the association between hospital volume and in-hospital mortality.

RESULTS

Overall in-hospital mortality rate was 13.4% (890 of 6650), highest after TAAD (463 of 2918, 15.9%), followed by TBAD (270 of 1934, 14.0%) and TEVAR (157 of 1798, 8.7%). Volume-outcome relationships for adjusted in-hospital mortality were demonstrated for TAAD and TBAD (P-trend < .001), but not TEVAR (P-trend = .11). Adjusted in-hospital mortality differed most for TAAD (fewer than 3 cases per year: 21%, 95% confidence interval, 18% to 24%; vs 11 or more cases per year: 12%, 95% confidence interval, 8% to 16%; P < .001) and TBAD (fewer than 2 cases per year: 18%, 95% confidence interval, 15% to 22%; vs 11 or more cases per year: 9%, 95% confidence interval, 5% to 12%; P < .001), whereas TEVAR did not differ between quartiles. Adjusted mortality was lower at centers with 26 or more overall annual thoracic dissection repairs, compared with any of the three lower-volume quartiles (P < .001).

CONCLUSIONS

This study demonstrated lower mortality at high-volume hospitals for overall repair of aortic dissection, persisting separately for surgical repair of TAAD and TBAD, but not TEVAR. As endovascular technology advances and practice patterns consequently change, analyses should focus on understanding the balance between procedural volume, mortality, and access to care for thoracic aortic dissection.

Evaluation of a Tennessee statewide initiative to reduce early elective deliveries using quasi-experimental methods

BACKGROUND

Concerted quality improvement (QI) efforts have been taken to discourage the practice of early elective deliveries (EEDs), but few studies have robustly examined the impact of directed QI interventions in reducing EED practices. Using quasi-experimental methods, we sought to evaluate the impact of a statewide QI intervention to reduce the practice of EEDs.

METHODS

Retrospective cohort study of vital records data (2007 to 2013) for all singleton births occurring ≥36 weeks in 66 Tennessee hospitals grouped into three QI cohorts. We used interrupted-time series to estimate the effect of the QI intervention on the likelihood of an EED birth statewide, and by hospital cohort. We compared the distribution of hospital EED percentages pre- and post-intervention. Lastly, we used multivariable logistic regression to estimate the effect of QI interventions on maternal and infant outcomes.

RESULTS

Implementation of the QI intervention was associated with significant declines in likelihood of EEDs immediately following the intervention (odds ratio, OR = 0.72; p < 0.001), but these results varied by hospital cohort. Hospital risk-adjusted EED percentages ranged from 1.6-13.6% in the pre-intervention period, which significantly declined to 2.2-9.6% in the post-intervention period (p < 0.001). The QI intervention was also associated with significant reductions in operative vaginal delivery and perineal laceration, and immediate infant ventilation, but increased NICU admissions.

CONCLUSIONS

A statewide QI intervention to reduce EEDs was associated with modest but significant declines in EEDs beyond concurrent and national trends, and showed mixed results in related infant and maternal outcomes.

Abstract 188: Burden of Complications After Thoracic Aortic Repair Surgery Among Medicare Beneficiaries

Objective: Despite the growth in thoracic aortic repair surgery, there remain concerns about the clinical and financial impact of complications secondary to these procedures. Therefore, we leveraged Medicare administrative claims to estimate the incidence, outcomes, and spending associated with complications during 90-day episodes of thoracic aortic repair surgery.

Methods and Results: Using a previously validated claims-based algorithm, we identified 11,240 Medicare fee-for-service beneficiaries hospitalized for thoracic aortic repair surgery [open type A (n=4,538), open type B (n=4,091), and thoracic endovascular aortic repair procedures (TEVAR, n=2,611)] from April 2014 to March 2015. We identified any (and total number) of the following complications within 30-day of surgery: renal failure, stroke/transient ischemic attack, respiratory failure, bleeding, pneumonia, deep vein thrombosis or pulmonary embolism, surgical site infection, paralysis, or acute myocardial infarction. Overall, 5,525 patients (49.2%) developed any complication (zero complications: 50.9%, one: 28.4%, two: 13.0%, three: 5.3%, or four or more: 2.4%). For the entire sample, 90-day episode mortality was 15.4%, which was higher in patients with any complication (23.0%) compared to patients without complications (8.1%). Adjusting for patient demographics, admission status, comorbidities, and hospital random effects, the relative odds of mortality comparing patients with and without complications was 2.41 (95% CI: 2.11-2.76) (Table). On average, 90-day episode spending was $54,668±$43,287, which was also higher among patients with any complication ($69,243 vs. $40,578, p<0.001). After similar adjustment, 90-day episode spending was 50% higher on a relative scale (95% CI: 46% to 54%), largely attributed to inpatient stays, post-acute care spending, and more frequent readmissions. Both mortality and spending increased significantly as the number of complications increased from zero to four or more.

Conclusions: Complications after thoracic aortic repair were common and associated with worse outcomes and higher episode spending. Identifying and intervening upon patient and provider factors predictive of complications is essential to improving the value of thoracic aortic repair procedures.

Center Variation in Medicare Spending for Durable Left Ventricular Assist Device Implant Hospitalizations

Importance

Hospitalizations for durable left ventricular assist device (LVAD) implants are expensive and increasingly common. Insights into center-level variation in Medicare spending for these hospitalizations are needed to inform value improvement efforts.

Objective

To examine center-level variation in Medicare spending for durable LVAD implant hospitalizations and its association with clinical outcomes.

Design, Setting, and Participants

Retrospective cohort study of linked Medicare administrative claims and Interagency Registry for Mechanically Assisted Circulatory Support (INTERMACS) clinical data comprising 106 centers in the United States providing durable LVAD implant. Centers were grouped into quartiles based on the mean price-standardized Medicare spending of their patients. The study included Medicare beneficiaries receiving primary durable LVAD implant between January 2008 and December 2014. Data were analyzed between November 2017 and October 2018.

Main Outcomes and Measures

Price-standardized Medicare payments and clinical outcomes. Overall and component (facility diagnosis-related group payments, outlier payments, physician services) payments and clinical outcomes (postimplant length of stay and adverse events) were compared across payment quartiles.

Results

The study sample included 4442 hospitalized patients, with mean (SD) age of 63.0 (10.8) years, 18.7% female, 27.2% nonwhite, and 6.1% Hispanic ethnicity. Among 4442 hospitalizations, the mean (SD) price-standardized Medicare payment was $176 825 ($60 286) and ranged from $122 953 to $271 472 across 106 centers. The difference in price-standardized payments between lowest and highest spending quartiles was $55 446 ($152 714 vs $208 160; 36%; P < .001), with outlier payments making up most of the difference ($42 742; 77%), followed by DRG ($6929; 13%) and physician services ($5774; 10%). After risk standardization, there was a modest decline in the difference in payments between quartiles ($53 221; 35%), with outlier payments accounting for a larger proportion of the difference (84%). After adjusting for patient characteristics, higher price-standardized payment quartiles were associated with longer postimplant length of stay but were not associated with any adverse events.

Conclusions and Relevance

Medicare payments for durable LVAD implant hospitalizations vary widely across centers; this was not well explained by prices or case mix. While associated with longer postimplant length of stay, increased spending was not associated with adverse events. As the supply and demand for durable LVAD therapy continues to rise, identifying opportunities to reduce variation in spending from both explained and unexplained sources will ensure high-value use.