Evaluation of readmission rates for carotid endarterectomy versus carotid artery stenting in the US Medicare population

Unplanned readmission after carotid stenting versus endarterectomy: analysis of the United States Nationwide Readmissions Database

BACKGROUND

Hospital readmissions are costly and reflect negatively on care delivered.

OBJECTIVE

To have a better understanding of unplanned readmissions after carotid revascularization, which might help to prevent them.

METHODS

The Nationwide Readmissions Database was used to determine rates and reasons for unplanned readmission following carotid endarterectomy (CEA) and carotid artery stenting (CAS). Trends were assessed by annual percent change, modified Poisson regression was used to estimate risk ratios (RR) for readmission, and propensity scores were used to match cohorts.

RESULTS

Analysis yielded 522 040 asymptomatic and 55 485 symptomatic admissions for carotid revascularization between 2010 and 2015. Higher 30-day readmission rates were noted after CAS versus CEA in both symptomatic (9.1% vs 7.7%, p<0.001) and asymptomatic (6.8% vs 5.7%, p<0.001) patients. Readmission rates trended lower over time, significantly so for 90-day readmissions in symptomatic patients undergoing CEA. The most common cause for 30-day readmission was stroke in both symptomatic (5.5%) and asymptomatic (3.9%) patients. Factors associated with a higher risk of readmission included age over 80; male gender; Medicaid health insurance; and increases in severity of illness, mortality risk, and comorbidity indices. Analysis of matched cohorts showed that CAS had higher readmission than CEA (RR=1.14 (95% CI 1.06 to 1.22); p<0.001) only in asymptomatic patients. Adverse events during initial admission which predicted 30-day readmission included acute renal failure and acute respiratory failure in asymptomatic patients; hematoma and cardiac events were additional predictive adverse events in symptomatic patients.

CONCLUSIONS

Readmission is not uncommon after carotid revascularization, occurs more often after CAS, and is predicted by baseline factors and by preventable adverse events at initial admission.

Accurate classification of carotid endarterectomy indication using physician claims and hospital discharge data

BACKGROUND AND PURPOSE

Studies of carotid endarterectomy (CEA) require stratification by symptomatic vs asymptomatic status because of marked differences in benefits and harms. In administrative datasets, this classification has been done using hospital discharge diagnosis codes of uncertain accuracy. This study aims to develop and evaluate algorithms for classifying symptomatic status using hospital discharge and physician claims data.

METHODS

A single center's administrative database was used to assemble a retrospective cohort of participants with CEA. Symptomatic status was ascertained by chart review prior to linkage with physician claims and hospital discharge data. Accuracy of rule-based classification by discharge diagnosis codes was measured by sensitivity and specificity. Elastic net logistic regression and random forest models combining physician claims and discharge data were generated from the training set and assessed in a test set of final year participants. Models were compared to rule-based classification using sensitivity at fixed specificity.

RESULTS

We identified 971 participants undergoing CEA at the Vancouver General Hospital (Vancouver, Canada) between January 1, 2008 and December 31, 2016. Of these, 729 met inclusion/exclusion criteria (n = 615 training, n = 114 test). Classification of symptomatic status using hospital discharge diagnosis codes was 32.8% (95% CI 29-37%) sensitive and 98.6% specific (96-100%). At matched 98.6% specificity, models that incorporated physician claims data were significantly more sensitive: elastic net 69.4% (59-82%) and random forest 78.8% (69-88%).

CONCLUSION

Discharge diagnoses were specific but insensitive for the classification of CEA symptomatic status. Elastic net and random forest machine learning algorithms that included physician claims data were sensitive and specific, and are likely an improvement over current state of classification by discharge diagnosis alone.

Predictors of 30-Day Unplanned Readmission After Carotid Artery Stenting Using Artificial Intelligence

Introduction

This study aimed to describe the rates and causes of unplanned readmissions within 30 days following carotid artery stenting (CAS) and to use artificial intelligence machine learning analysis for creating a prediction model for short-term readmissions. The prediction of unplanned readmissions after index CAS remains challenging. There is a need to leverage deep machine learning algorithms in order to develop robust prediction tools for early readmissions.

Methods

Patients undergoing inpatient CAS during the year 2017 in the US Nationwide Readmission Database (NRD) were evaluated for the rates, predictors, and costs of unplanned 30-day readmission. Logistic regression, support vector machine (SVM), deep neural network (DNN), random forest, and decision tree models were evaluated to generate a robust prediction model.

Results

We identified 16,745 patients who underwent CAS, of whom 7.4% were readmitted within 30 days. Depression [p < 0.001, OR 1.461 (95% CI 1.231–1.735)], heart failure [p < 0.001, OR 1.619 (95% CI 1.363–1.922)], cancer [p < 0.001, OR 1.631 (95% CI 1.286–2.068)], in-hospital bleeding [p = 0.039, OR 1.641 (95% CI 1.026–2.626)], and coagulation disorders [p = 0.007, OR 1.412 (95% CI 1.100–1.813)] were the strongest predictors of readmission. The artificial intelligence machine learning DNN prediction model has a C-statistic value of 0.79 (validation 0.73) in predicting the patients who might have all-cause unplanned readmission within 30 days of the index CAS discharge.

Conclusions

Machine learning derived models may effectively identify high-risk patients for intervention strategies that may reduce unplanned readmissions post carotid artery stenting.

Central Illustration

Figure 2: ROC and AUPRC analysis of DNN prediction model with other classification models on 30-day readmission data for CAS subjects

Supplementary Information

The online version contains supplementary material available at 10.1007/s12325-021-01709-7.

We present a novel deep neural network-based artificial intelligence prediction model to help identify a subgroup of patients undergoing carotid artery stenting who are at risk for short-term unplanned readmissions. Prior studies have attempted to develop prediction models but have used mainly logistic regression models and have low prediction ability. The novel model presented in this study boasts 79% capability to accurately predict individuals for unplanned readmissions post carotid artery stenting within 30 days of discharge.

Risk factors associated with 30-day hospital readmission after carotid endarterectomy

OBJECTIVE

The current study evaluated all-cause 30-day readmissions after carotid endarterectomy.

METHODS

Patients undergoing carotid endarterectomy were selected from the Cerner Health Facts® database using ICD-9-CM procedure codes from their index admission. Readmission within 30 days of discharge was determined. Chi-square analysis determined characteristics of the index admission (demographics, diagnoses, postoperative medications, and laboratory results) associated with readmission. Multivariate logistic regression models were used to identify characteristics independently associated with readmission.

RESULTS

In total, 5257 patients undergoing elective carotid endarterectomy were identified. Readmission within 30 days was 3.1%. After multivariable adjustment, readmission was associated with end-stage renal disease (OR: 3.21, 95% CI: 1.01-10.2), hemorrhage or hematoma (OR: 2.34, 95% CI: 1.15-4.77), procedural complications (OR: 3.07, 95% CI: 1.24-7.57), use of bronchodilators (OR: 1.48, 95% CI: 1.03-2.11), increased Charlson index scores (OR: 1.22, 95% CI: 1.08-1.38), and electrolyte abnormalities (hyponatremia < 135 mEq/L (OR: 1.69, 95% CI: 1.07-2.67) and hypokalemia less than 3.7 mEq/L (OR: 2.26, 95% CI: 1.03-4.98)).

CONCLUSIONS

Factors associated with readmission following carotid endarterectomy included younger age, increased comorbidity burden, end-stage renal disease, electrolyte disorders, the use of bronchodilators, and complications including bleeding (hemorrhage or hematoma). Of note, in this real-world study, only 40% of the patients received protamine, despite evidence-based literature demonstrating the reduced risk of bleeding complications. As healthcare moves towards quality of care-driven reimbursement, physician modifiable targets such as protamine utilization to reduce bleeding are greatly needed to reduce readmission, and failure to reduce preventable physician-driven complications after carotid interventions may be associated with decreased reimbursement.

Hidden Readmissions after Carotid Endarterectomy and Stenting

BACKGROUND

Historically, carotid procedures incur a readmission rate of approximately 6%; however, these studies are not nationally representative and are limited to tracking only the index hospitals. We sought to evaluate a nationally representative database for readmission rates (including different hospitals) after both carotid endarterectomy (CEA) and carotid artery stenting (CAS) and determine risk factors for poor outcomes including postoperative mortality and myocardial infarction.

METHODS

This study was a retrospective analysis utilizing the 2010-2014 Nationwide Readmissions Database to query patients aged >18 years undergoing CEA or CAS. Outcomes included initial admission mortality, and 30-day readmission, including mortality and myocardial infarction (MI). Univariable analysis of 39 demographic, clinical, and hospital variables was conducted with significance set at P < 0.05. Significant variables were included in a multivariable logistic regression to identify independent risk factors for readmission. Results were weighted for national estimates.

RESULTS

There were 527,622 patients undergoing carotid procedures and 13% (n = 69,187) underwent CAS. The 30-day readmission rate was 7% (n = 35,782), and of those, 25% (n = 8,862) were readmitted to a different hospital. When controlling for other factors, CAS was a risk factor for mortality at both index admission (odds ratio [OR] 2.29 [2.11-2.49]) and 30-day readmission (OR 1.48 [1.3-1.69]) and 30-day readmissions at both index hospital (OR 1.11 [1.07-1.14]) and different hospital (OR 1.38 [1.29-1.48]). Readmission to a different hospital increased mortality risk (OR 1.45 [1.29-1.63]) but did not have an effect on MI. Postoperative infections comprised 15% of readmissions while 6% of all readmissions were for stroke.

CONCLUSIONS

Previously unreported, one in 4 readmissions after carotid procedures occur at a different hospital and this fragmentation of care could increase mortality risk after carotid procedures particularly for CAS which was also an independent risk factor for postoperative mortality and readmissions. Further validation is required to decrease unnecessary hospital after carotid procedures.

Socioeconomic Disparities in Carotid Revascularization Procedures

OBJECTIVES

Several studies have demonstrated healthcare disparities in postoperative outcomes after carotid endarterectomy and carotid artery stenting, including increased hospital mortality, postoperative stroke, and readmission rates. The objective of the present study was to examine the intersectionality between race/ethnicity, insurance status, and postoperative outcomes in carotid procedures.

DESIGN

Records of adults from 2007 to 2014 were retrospectively identified, and patients with appropriate International Classification of Diseases Ninth Revision Clinical Modification codes for carotid endarterectomy or carotid artery stenting were identified. Primary outcomes were unadjusted rates and adjusted odds ratios (aORs) of postoperative in-hospital mortality, stroke, combined stroke/mortality, and cardiovascular complications.

SETTING

Data were sourced from the State Inpatient Databases data from California, Florida, Kentucky, Maryland, and New York during the years 2007 to 2014.

PARTICIPANTS

Patients undergoing carotid revascularization procedures.

INTERVENTIONS

The effects of race and insurance status as independent variables and as effect modifiers on postoperative outcomes.

MEASUREMENTS AND MAIN RESULTS

Multivariable logistic regression models were used to examine the associations between race and/or insurance status with respect to study outcomes. Race, but not payer status, was significantly associated with adverse outcomes after carotid artery procedures, with blacks, Hispanics, and other non-Caucasian races demonstrating a significantly greater risk of postoperative stroke and mortality (aOR range 1.24-1.59). This relationship persisted even when stratified by procedure type (aOR range 1.25-1.56) and symptomatology (aOR range 1.51-1.63).

CONCLUSIONS

These results suggest that disparities in postoperative outcomes after carotid artery procedures are associated with race but not with primary insurance status. Multiple contributing factors exist, including racial inequities in prevalence of comorbidities, health literacy, and procedure type performed.

Association of neutrophil-to-lymphocyte ratio with outcomes after elective abdominal aortic aneurysm repair

Data are lacking regarding real-time prediction of postoperative complications after elective aneurysm repair. The neutrophil-to-lymphocyte ratio (NLR) has been evaluated as a predictor of outcomes after cardiac and infrapopliteal interventions and is associated with poor outcomes for critical limb ischemia. We examined NLR and outcomes after abdominal aortic aneurysm (AAA) repair. Inpatients undergoing elective AAA repair (2008 to 2015) were selected from the Cerner Health Facts database using International Classification of Disease (9th edition) procedure codes. Postoperative outcomes were identified using data from patient records within 1 week after surgery. NLR was calculated by dividing the absolute neutrophil count by the absolute lymphocyte count. The receiver operating characteristic curve was analyzed to define low and high postoperative NLR groups. Chi-square analysis and multivariable logistic regression models were used to identify characteristics (demographics, diagnoses, postoperative NLR) associated with postoperative complications. Elective AAA repair occurred in 5,655 patients. Of these, we could calculate postoperative NLR for 1,908 (34%), with 1,529 undergoing endovascular repair and 379 undergoing an open repair. Compared with patients with low postoperative NLR, patients with high postoperative NLR experienced longer hospital stays (5.7 vs 2.6 days, P < .0001); higher rates of in-hospital death (2.9% vs 1.4%, P = .002); higher rates of renal failure (11.6% vs 3.9%, P < .0001); cardiac problems or myocardial infarction (3.8% vs 1.2%, P = .0002); respiratory problems (13.3% vs 5.8%, P < .0001); and infection (8.9% vs 2.9%, P < .0001). The association between high postoperative NLR and adverse postoperative outcomes persisted on multivariable analysis. This included infection (odds ratio [OR], 2.59; 95% confidence interval [CI], 1.65-4.07), renal failure (OR, 2.19; 95% CI, 1.45-3.31), cardiac events (OR, 2.41; 95% CI, 1.21-4.77), and respiratory problems (OR, 1.73; 95% CI, 1.22-2.45).NLR was associated with adverse outcomes after elective endovascular and open AAA repair. An elevated NLR within 1 week after surgery was strongly associated with postoperative complications, and may identify at-risk patients who require closer follow-up. Given the perilous nature of vascular surgery and the risk-benefit ratio for prophylactic aneurysm repair, future study of postoperative outcome and preoperative NLR is needed to provide clinically important risk profiles before treatment decisions.

Cohort study of risk factors for 30-day readmission after abdominal aortic aneurysm repair

Background: We conducted a retrospective cohort study of thirty-day readmission after abdominal aortic aneurysm (AAA) repair. Patients and methods: Inpatients (2009-2016) undergoing elective AAA repair were selected from the multicenter Cerner Health Facts® database using ICD-9 procedure codes. We identified characteristics associated with 30-day readmission with chi-square analysis and logistic regression. Results: 4,723 patients undergoing elective AAA procedures were identified; 3,101 endovascular aneurysm repairs (EVAR) and 1,622 open procedures. Readmission differed by procedure type (6.5 % EVAR vs. 9.3 % open, p =.0005). Multivariable logistic regression found that patients undergoing EVAR were less likely to be readmitted (OR 0.71, 95 % CI 0.54-0.92) than patients undergoing open repair. The following risk factors were associated with 30-day readmission following any AAA repair: surgical site infection during the index admission (OR 2.79, 95 % CI 1.25-6.22), age (OR 1.03, 95 % CI 1.01-1.05), receipt of bronchodilators (OR 1.34, 95 % CI 1.06-1.70) or steroids (OR 1.45, 95 % CI 1.04-2.02), serum potassium > 5.2 mEq/L (OR 1.89, 95 % CI 1.16-3.06), and higher Charlson co-morbidity scores (OR 1.12, 95 % CI 1.04-1.21). Subgroup analysis revealed that age (OR 1.02, 95 % CI 1.01-1.04), higher Charlson comorbidity scores (OR 1.20, 95 % CI 1.09-1.33), and receipt of post-operative bronchodilators (OR 1.39, 95 % CI 1.03-1.88) were risk factors for 30-day readmission following EVAR. After open procedures, readmission was associated with surgical site infection during the index admission (OR 2.91, 95 % CI 1.17-7.28), chronic heart failure (OR 2.18, 95 % CI 1.22-3.89), and receipt of post-operative steroids (OR 1.92, 95 % CI 1.24-2.96). The most common infections were pneumonia after open procedures and urinary tract infection after EVAR. Conclusions: The risk factor most associated with 30-day readmission after elective AAA repair was surgical site infection. Awareness of these risk factors and vulnerable groups may help identify high-risk patients who could benefit from increased surveillance programs to reduce readmission.

Thirty-day Readmission Rates for Carotid Endarterectomy Versus Carotid Artery Stenting

BACKGROUND

Because of the emergence of readmission-related Medicare penalties, efforts are being made to identify and reduce patient readmissions. The purpose of this study was to compare rates and risk factors for 30-d readmission and hospital length of stay (LOS) after carotid endarterectomy (CEA) and carotid artery stenting (CAS) among patients treated for carotid artery stenosis in Pennsylvania.

MATERIALS AND METHODS

Data were from the Pennsylvania Health Care Cost Containment Council (PHC4). We identified 15,966 patients who underwent CEA (n = 13,557) or CAS (n = 2409) in Pennsylvania between 2011 and 2014. Logistic regression was used to determine risk factors for 30-d readmission, whereas linear regression was used to model factors influencing LOS. Propensity score analysis was used to control for imbalanced covariates between procedures.

RESULTS

Thirty-day readmission rates in Pennsylvania after CEA and CAS for carotid artery stenosis were similar (9.8% and 9.6%, respectively; P = 0.794). Not home discharge destination, Charlson comorbidity index ≥2, and LOS >1 d were all significantly associated with readmission risk. Procedure type (CEA or CAS) did not significantly influence risk. A significant difference in LOS was found between CEA and CAS, but the magnitude of the difference was small (2.38 for CAS versus 2.59 for CEA; P = 0.007). Black race, urgent and emergent cases, and not home discharges significantly increased LOS by notable amounts (1, 1.5, 3.9, and 1.9 d, respectively).

CONCLUSIONS

Carotid artery stenosis patients in Pennsylvania undergoing CEA or CAS had similar 30-d readmission rates. Although LOS was significantly different, the magnitude of the difference was not large.

Impact of Patient Safety Indicators on readmission after abdominal aortic surgery

Patient safety is a critical component of health-care quality and measures created by the Agency for Healthcare Research and Quality (AHRQ) to identify hospitalizations with potentially preventable adverse events. This analysis evaluated whether Patient Safety Indicator (PSI) events after open surgical repair (OSR) or endovascular aneurysm repair (EVAR) of abdominal aortic aneurysm (AAA) were associated with increased risk of readmission. Patients undergoing elective repair of nonruptured AAA from 2009 to 2012 were selected in the Medicare Provider Analysis and Review files using the International Classification of Diseases, Ninth Revision, Clinical Modification codes. To identify PSI events, we used the AHRQ PSI International Classification of Diseases, Ninth Revision, Clinical Modification numerator codes. Chi-square test, multivariable logistic regression analysis, nonparametric Wilcoxon rank sum test, and Kaplan-Meier survival analysis were used for statistics. A total of 66,923 patients undergoing elective AAA repair were evaluated: (1) 9,315 with OSR and (2) 57,608 with EVAR. The most frequent PSI events after OSR versus EVAR were postoperative respiratory failure (PSI, 11; 17.7% vs 1.8%; P < .0001); perioperative hemorrhage/hematoma (PSI, 9; 3.6% vs 2.6%; P < .0001); postoperative sepsis (PSI, 13; 3.5% vs 0.4%; P < .0001); accidental puncture or laceration (PSI, 15; 2.1% vs 0.6%; P < .0001); and postoperative acute kidney injury requiring dialysis (PSI, 10; 1.4% vs 0.2%; P < .0001). The overall 30-day readmission rate was 10.5%. The occurrence of any PSI event overall significantly increased 30-day readmission compared with no event cases (odds ratio [OR] = 1.71; 95% confidence interval [CI], 1.57-1.86). Likelihood of 30-day readmission was greater for postoperative acute kidney injury requiring dialysis (OR = 1.66; 95% CI, 1.28-2.15), postoperative respiratory failure (OR = 1.36; 95% CI, 1.22-1.52), perioperative hemorrhage (OR = 1.34; 95% CI, 1.18-1.52), and postoperative pressure ulcer (OR = 2.88; 95% CI, 1.99-4.17). Occurrence of any PSI event was associated with an increased total hospital and intensive care unit length of stay and total hospital charges (all P < .001). In conclusion, AHRQ PSI events may be used to identify patients at the greatest risk for readmission after AAA repair. The risk for 30-day readmission was 71% higher when a PSI event occurred and was not associated with the type of repair. Minimizing preventable PSI events may be beneficial to reducing hospital readmissions after open and endovascular AAA repair and to improving hospital resource utilization.

Risk assessment of comorbidities on 30-day avoidable hospital readmissions among internal medicine patients

RATIONALE, AIMS AND OBJECTIVES

Reducing the rate of hospital readmissions, particularly avoidable ones, has significant implications on patient outcomes, cost containment, and quality of care. Given that the reason of readmission may differ from the patient's main diagnosis in the index admission, this study aims to assess the influence of index comorbidities on the primary readmission diagnoses and explore the risk of deemed avoidable readmission because of prior comorbidities.

METHODS

A retrospective review of 3962 discharges was conducted at a 527-bed teaching hospital in Jordan, utilizing data related to 2025 internal medicine patients.

RESULTS

Among all discharges, 29% were followed by a 30-day readmission, of which 13% were identified as potentially avoidable. Of all readmissions, 36% of patients were readmitted because of one of the comorbidities that had been identified at index admission. In addition, 47% of the potentially avoidable readmissions had a main diagnosis that was one of the index comorbidities. The results also showed an association between readmission for one of the index stay's comorbidities and being avoidable, with an adjusted odds ratio of 2.12 (95% confidence interval, 1.65-2.72). Overall, the presence of certain diseases, being identified as one of the preceding comorbidities, was found to have a substantial influence on the risk of potentially avoidable readmission. These diseases included digestive, circulatory, respiratory, genitourinary systems, and infectious and parasitic diseases (adjusted relative risks = 1.57, 1.49, 1.36, 1.30, and 2.30, respectively).

CONCLUSION

To help reduce the rates of readmission, potential gains seem available if hospitals adopt clinical practices that support the patient's care during the post-discharge transition. This implies that health care providers need to pay more attention to the comorbidities of high-risk patients to be closely monitored after discharge.

Carotid stenting versus endarterectomy for the treatment of carotid artery stenosis: Contemporary results from a large single center study

OBJECTIVE

To compare the complication rates associated with carotid endarterectomy (CEA) versus carotid artery stenting (CAS).

BACKGROUND

Carotid stenosis is a well-known cause of stroke and increased mortality. The safety of carotid revascularization may be related to symptom status, medical comorbidities, use of embolic protection devices, as well as operator experience and these factors may vary across patient populations within a single operating center.

METHODS

We retrospectively analyzed patients with carotid artery stenosis admitted to our hospital for carotid revascularization between January 1, 2007 and December 1, 2013. The primary end point was a composite endpoint of periprocedural death, stroke, and myocardial infarction (MI).

RESULTS

Of the 718 patients admitted for carotid revascularization 525 (73.1%) underwent CEA and 193 (26.9%) underwent CAS. Both groups demonstrated similar rates of the composite endpoint, MI, and death; the stenting group demonstrated a higher rate of stroke (4.2% vs. 1.3%; P = 0.020). Adjusting for baseline medical comorbidities and symptom status mitigated this difference (P = 0.091 and 0.113, respectively). When stratified by department performing CAS, there was a significant difference in the occurrence of stroke (P = 0.033), which likewise disappeared in the multivariate regression analysis.

CONCLUSION

The risk of the composite endpoint did not differ significantly between those undergoing CAS versus CEA. The stenting group demonstrated a higher rate of periprocedural stroke, which was also apparent when patients were stratified by stenting department. These differences were likely driven by variation in baseline medical comorbidities and symptom status. © 2016 Wiley Periodicals, Inc.

Carotid Endarterectomy: Current Concepts and Practice Patterns

Background Stroke is the number one cause of disability and third leading cause of death among adults in the United States. A major cause of stroke is carotid artery stenosis (CAS) caused by atherosclerotic plaques. Randomized trials have varying results regarding the equivalence and perioperative complication rates of stents versus carotid endarterectomy (CEA) in the management of CAS. Objectives We review the evidence for the current management of CAS and describe the current concepts and practice patterns of CEA. Methods A literature search was conducted using PubMed to identify relevant studies regarding CEA and stenting for the management of CAS. Results The introduction of CAS has led to a decrease in the percentage of CEA and an increase in the number of CAS procedures performed in the context of all revascularization procedures. However, the efficacy of stents in patients with symptomatic CAS remains unclear because of varying results among randomized trials, but the perioperative complication rates exceed those found after CEA. Conclusions Vascular surgeons are uniquely positioned to treat carotid artery disease through medical therapy, CEA, and stenting. Although data from randomized trials differ, it is important for surgeons to make clinical decisions based on the patient. We believe that CAS can be adopted with low complication rate in a selected subgroup of patients, but CEA should remain the standard of care. This current evidence should be incorporated into practice of the modern vascular surgeon.

Carotid Endarterectomy versus Carotid Artery Stenting: No Difference in 30-Day Postprocedure Readmission Rates

BACKGROUND

In the United States, ischemic stroke is a major cause of morbidity and mortality, precipitated by carotid artery stenosis in 1 of every 5 individuals who suffer a stroke. Carotid endarterectomy (CEA) and carotid artery stenting (CAS) are 2 proven means of intervening on this disease process, with similar patient outcomes. Little is known about the burden of readmission after each of these procedures. We hypothesized that no difference in readmission rates within 30 days would exist for these 2 procedures, in spite of baseline differences that might exist between the 2 patient populations.

METHODS

Using the Pennsylvania Health Care Cost Containment Council database, we identified 4,319 people who underwent CEA (n = 3,640) or CAS (n = 679) in Pennsylvania in 2011. Univariate analyses were performed to compare patient characteristics and outcomes, including reasons for readmission, between patients who underwent CEA and those who underwent CAS. Logistic regression was used to estimate the effect of intervention on 30-day readmission, after controlling for potential confounders. Time to readmission was analyzed using the Kaplan-Meier method.

RESULTS

Patients who underwent CEA and CAS differed in a few notable ways, including age, race, admission type, and comorbid conditions such as congestive heart failure, hemiplegia and paraplegia, and renal disease. The unadjusted rate of 30-day readmission was 9.37% for CEA and 10.75% for CAS (P = 0.26). After controlling for patient and procedure characteristics, differences between 30-day readmission rates were still not statistically significant (odds ratio = 1.13; P = 0.39). Finally, time to readmission was similar for those who underwent CEA and those who underwent CAS (P = 0.19). Complications associated with surgery comprised less than 10% of primary readmission diagnoses for both groups.

CONCLUSIONS

Readmission rates after CEA and CAS for carotid artery stenosis are approximately 10%. In spite of differences between patients with carotid stenosis who are selected for endarterectomy and stenting, the choice of procedure does not appear to be associated with different readmission rates or time to readmission, even after controlling for patient characteristics.

Rates and predictors of 5-year survival in a national cohort of asymptomatic elderly patients undergoing carotid revascularization

BACKGROUND

Current American Heart Association guidelines recommend carotid revascularization for asymptomatic patients on the basis of life expectancy.

OBJECTIVE

To determine the rates and predictors of 5-year survival in elderly patients with asymptomatic carotid artery stenosis who underwent either carotid artery stent placement (CAS) or carotid endarterectomy (CEA).

METHODS

The rates of 5-year survival were determined by use of Kaplan-Meier survival methods in a representative sample of fee-for-service Medicare beneficiaries ≥65 years of age who underwent CAS or CEA for asymptomatic carotid artery stenosis with postprocedural follow-up of 3.4 ± 1.7 years. Cox proportional hazards analysis was used to assess the relative risk of all-cause mortality for patients in the presence of selected comorbidities, including ischemic heart disease, chronic renal failure, and atrial fibrillation, after adjustment for potential confounders such as age, sex, race/ethnicity, and procedure type.

RESULTS

A total of 22,177 patients with asymptomatic carotid artery stenosis were treated with either CAS (n = 2144) or CEA (n = 20,033). The overall estimated 5-year survival rate (±SE) was 95.3 ± 0.00149; it was 95.5% and 93.8% in patients treated with CEA and CAS, respectively. After adjustment for potential confounders, relative risk of all-cause 5-year mortality was significantly higher among patients with atrial fibrillation (relative risk, 1.8; 95% confidence interval, 1.5-2.1) and those with chronic renal failure (relative risk, 2.1; 95% confidence interval, 1.7-2.6).

CONCLUSION

Risks and benefits must be carefully weighed before carotid revascularization in elderly patients with asymptomatic carotid artery stenosis who have concurrent atrial fibrillation or chronic renal failure.

Readmissions after carotid artery revascularization in the Medicare population

BACKGROUND

In appropriately selected patients with severe carotid stenosis, carotid revascularization reduces ischemic stroke. Prior clinical research has focused on the efficacy and safety of carotid revascularization, but few investigators have considered readmission as a clinically important outcome.

OBJECTIVES

The aims of this study were to examine frequency, timing, and diagnoses of 30-day readmission following carotid revascularization; to assess differences in 30-day readmission between patients undergoing carotid endarterectomy (CEA) and carotid artery stenting (CAS); to describe hospital variation in risk-standardized readmission rates (RSRR); and to examine whether hospital variation in the choice of procedure (CEA vs. CAS) is associated with differences in RSRRs.

METHODS

We used Medicare fee-for-service administrative claims data to identify acute care hospitalizations for CEA and CAS from 2009 to 2011. We calculated crude 30-day all-cause hospital readmissions following carotid revascularization. To assess differences in readmission after CAS compared with CEA, we used Kaplan-Meier survival curves and fitted mixed-effects logistic regression. We estimated hospital RSRRs using hierarchical generalized logistic regression. We stratified hospitals into 5 groups by their proportional CAS use and compared hospital group median RSRRs.

RESULTS

Of 180,059 revascularizations from 2,287 hospitals, CEA and CAS were performed in 81.5% and 18.5% of cases, respectively. The unadjusted 30-day readmission rate following carotid revascularization was 9.6%. Readmission risk after CAS was greater than that after CEA. There was modest hospital-level variation in 30-day RSRRs (median: 9.5%; range 7.5% to 12.5%). Variation in proportional use of CAS was not associated with differences in hospital RSRR (range of median RSRR across hospital groups 9.49% to 9.55%; p = 0.771).

CONCLUSIONS

Almost 10% of Medicare patients undergoing carotid revascularization were readmitted within 30 days of discharge. Compared with CEA, CAS was associated with a greater readmission risk. However, hospitals' RSRR did not differ by their proportional CAS use.