Readmission rates after lower extremity bypass vary significantly by surgical indication

A qualitative study evaluating the discharge process for vascular surgery patients to identify significant themes for organizational improvement

OBJECTIVE

Transition from the hospital to an outpatient setting is a multifaceted process requiring coordination among a variety of services and providers to ensure a high-quality discharge. Vascular surgery patients comprise a complex population that experiences high unplanned readmission rates. We performed a qualitative study to identify themes for process improvement for vascular surgery patients. A validated discharge process, RED (Re-Engineered Discharge), was used to identify additional actionable themes to create a more efficient discharge process tailored specifically to the vascular surgery population.

METHODS

A prospective, qualitative analysis at a tertiary center using a semi-structured focus group interview guide was performed to evaluate the current discharge process and identify opportunities for improvement. Focus groups were Zoom recorded, transcribed into electronic text files, and were loaded into Dedoose qualitative software for analysis using a directed content analysis approach. Two researchers independently thematically coded each transcript, starting with accepted discharge components to identify new thematic categories. Prior to analysis, all redundancy of codes was resolved, and all team members agreed on text categorization and coding.

RESULTS

Eight focus groups with a total of 38 participants were conducted. Participants included physicians (n = 13), nursing/ancillary staff (n = 14), advanced nurse practitioners (n = 2), social worker/dietitian/pharmacist (n = 3), and patients (n = 6). Transcript analyses revealed facilitators and barriers to the discharge process. In addition to traditional RED components, unique concepts pertinent to vascular surgery patients included patient complexity, social determinants of health, technology literacy, complexity of ancillary services, discharge appropriateness, and use of advanced nurse practitioners for continuity.

CONCLUSIONS

Specific themes were identified to target and enhance the future vRED (vascular Re-Engineered Discharge) bundle. Thematic targets for improvement include increased planning, organization, and communication prior to discharge to address vascular surgery patients' multiple comorbidities, extensive medication lists, and need for complex ancillary services at the time of discharge. Other thematic barriers discovered to improve include provider awareness of patient health literacy, patient understanding of complex discharge instructions, patient technology barriers, and intrinsic social determinants of health in this population. To address these discovered barriers, organizational targets to improve include enhanced social support, the use of advanced nurse practitioners for education reinforcement, and increased coordination. These results provide a framework for future quality improvement targeting the vascular surgery discharge process.

Readmission After Lower Extremity Bypass Following Discharge to a Rehabilitation or Nursing Facility

INTRODUCTION

Hospital readmission after lower extremity arterial bypass (LEB) is common. Patients are often discharged to a facility after LEB as a bridge to home. Our objective was to define the association between discharge to a facility and readmission after LEB.

METHODS

We used the Vascular Quality Initiative to study patients who underwent LEB from 2017 to 2022. The primary exposure was discharge location. The primary outcome was 30-d hospital readmission.

RESULTS

We included 6076 patients across 147 centers. The overall 30-d readmission rate was 18%. Readmission occurred among 15% of patients discharged home, 22% of patients discharged to a rehabilitation facility, and 25% of patients discharged to a nursing home. After controlling for patient and procedural factors, there was no significant association between discharge location and 30-d readmission (rehabilitation versus home odds ratio: 1.06, 95% confidence interval: 0.87-1.29; nursing facility versus home odds ratio: 1.21, 95% confidence interval: 0.99-1.47). Female sex, end-stage renal disease, diabetes, heart failure, pulmonary disease, smoking, preoperative functional impairment, tibial bypass target, critical limb threatening or acute ischemia, and postoperative complications including surgical site infection, change in renal function and graft thrombosis were associated with an increased likelihood of readmission.

CONCLUSIONS

Patients discharged home after LEB experienced a similar likelihood of readmission as those discharged to a facility. While discharge to a facility may aid in care transitions, it did not appear to lead to reduced 30-d readmissions. The recommended discharge location should be predicated on patient care needs and not as a perceived mechanism to reduce readmissions.

A Meta-Analysis to Derive Population-Based Quality Benchmarks of the Incidence of Surgical Site Infection After Lower Limb Revascularization Surgery

OBJECTIVES

The reported incidence of surgical site infection (SSI) after lower limb revascularization surgery varies. We conducted a systematic review and meta-analysis of population-based studies reporting the incidence of SSI in adults who underwent these surgeries in high-income countries to derive SSI quality benchmarks.

METHODS

We searched MEDLINE, EMBASE, CENTRAL, and Evidence-Based Medicine Reviews (inception-to-April 28th, 2022) for population-based studies estimating the cumulative incidence of SSI among adults who underwent lower limb revascularization surgery for peripheral artery disease (PAD) in high-income countries. Two investigators independently screened abstracts and full-text articles, extracted data, and assessed risks of bias. We used random-effects models to pool data and GRADE to assess certainty.

RESULTS

Among 6258 citations, we included 53 studies (n=757,726 patients); eight of which (n=435,769 patients) reported non-overlapping data that were meta-analyzed. The pooled cumulative incidence of any SSI was 6.0 in 100 patients [95% confidence interval (CI)=4.3-8.0 in 100 patients; n=8 studies; n=435,769 patients; moderate certainty]. The cumulative incidence of Szilagyi grade I (cellulitis), grade II (subcutaneous tissue), and grade III (prosthetic graft) SSI was 6.5 in 100 patients (95% CI=4.3-8.6 in 100 patients; n=2 studies; n=39,645 patients; low certainty), 2.1 in 100 patients (95% CI=2.0-2.3 in 100 patients; n=2 studies; low certainty), and 0.4 in 100 patients (95% CI=0.4-0.4 in 100 patients; n=1 study; n=333,275 patients; low certainty), respectively. The pooled cumulative incidence of any early (in-hospital/≤30-days) and late (>30-days) SSI was 6.2 in 100 patients (95% CI=4.4 to 8.0 in 100 patients; n=7 studies; n=431,273 patients; moderate certainty) and 3.7 in 100 patients (95% CI=2.2-5.2 in 100 patients; n=2 studies; n=10,565 patients; low certainty), respectively.

CONCLUSIONS

This systematic review derived population-based benchmarks of the incidence of any SSI; Szilagyi I, II, and III SSI; and early and late SSI after lower limb revascularization surgery. These may be used by practicing surgeons and healthcare leaders/administrators to guide quality improvement efforts in the United States and perhaps other countries.

A Systematic Review and Meta-Analysis to Assess the Impact of Pre-existing Comorbidities on the 30-Day Readmission after Lower Extremity Bypass Surgery for Peripheral Artery Occlusive Disease

BACKGROUND

Unplanned hospital readmissions after surgical operations are considered a marker for suboptimal care during index hospitalizations and are associated with poor patient outcomes and increased healthcare resource utilization. Patients undergoing lower extremity bypass (LEB) operations for severe peripheral arterial disease (PAD) have one of the highest readmission rates, among all the vascular and nonvascular surgical operations. This review is meant to evaluate the impact of pre-existing comorbidities (diabetes mellitus (DM), chronic obstructive pulmonary disease (COPD), congestive heart failure (CHF), hypertension (HTN), and coronary artery disease (CAD))-on the 30-day readmission rates among patients who underwent LEB for severe PAD.

METHODS

The review protocol was registered to the PROSPERO database (CRD42021261067). A systematic review of the English literature was performed using PubMed, Scopus, and the Cochrane Library databases from inception till April 2022. The review was based on the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) guidelines and included only studies reporting on 30-day readmission following LEB for occlusive PAD. The quality of evidence was assessed using the Grading of Recommendations, Assessment, Development, and Evaluations (GRADE) approach and was reported as high, moderate, or low. The risk of bias was evaluated utilizing the Risk of Bias in Nonrandomized Studies - of Interventions (ROBINS-I) tool. A pooled odds ratio (OR) for each study was computed, and a P-value of <0.05 was designated as statistically significant. Interstudy heterogeneity was evaluated by Q-metric and quantified using Higgins I² statistics.

RESULTS

Five studies reported data on 30-day readmission after LEB for occlusive PAD. A total of 19,739 patients were included. Readmission occurred among 3,559 (18%) patients. DM and COPD were reported by all 5 selected studies, and CHF and HTN were reported by 4 studies. CAD was least reported among the selected 5 pre-existing conditions, with only 2 studies mentioning it. HTN (OR, 1.35; 95% confidence interval (CI), 1.10-1.64; P ≤ 0.001; I² = 52.20%), DM (OR, 1.52; 95% CI, 1.30-1.79; P ≤ 0.001; I² = 74.51%), and CHF (OR, 1.85; 95% CI, 1.51-2.25; P ≤ 0.001; I² = 50.48%) were all found to be associated with an increased risk of 30-day readmission, while the presence of COPD (OR, 1.16; 95% CI, 0.98-1.36; P = 0.09; I² = 61.93%) and CAD (OR, 1.30; 95% CI, 0.94-1.78; P = 0.11; I² = 51.01%) was not associated with early readmission on meta-analysis of the available studies.

CONCLUSIONS

The pre-existing comorbidities HTN, DM, and CHF increase the risk of 30-day readmission after LEB for occlusive PAD. The identification of these risk factors can help stratify the patients and further guide in understanding the variety of factors that contribute in hospital readmissions.

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.

The Association of the Day of the Week with Outcomes of Infrainguinal Lower Extremity Bypass

BACKGROUND

The day of the week (DOW) for performing procedures and operations has been shown to affect clinical and resource utilization outcomes. Limited published data are available on vascular surgery operations. Our primary objective was to assess outcomes by DOW for infrainguinal lower extremity bypass (LEB) performed for claudication or rest pain. The secondary objective was to assess outcomes by DOW for LEBs performed for tissue loss.

METHODS

The Vascular Quality Initiative was queried from 2003 to 2018 for all elective index infrainguinal LEBs performed for claudication or rest pain. Cases performed for acute limb ischemia as well as concomitant peripheral vascular intervention, nonelective LEBs, sequential grafts, and weekend cases were excluded. LEBs were grouped by DOW: Monday-Tuesday (early weekdays) versus Wednesday-Friday (later weekdays). Baseline data, operative details, and outcomes were collected. Univariate and multivariable analyses were performed. LEBs performed for claudication/rest pain were analyzed together while tissue loss was assessed separately.

RESULTS

There were 12,084 LEBs identified-44.5% performed on Monday-Tuesday and 55.5% on Wednesday-Friday. Overall, the mean age was 65.6 years, 68.6% were male, and 82.8% were Caucasian. LEBs were performed for claudication in 57.4% of cases. An autogenous great saphenous vein was used in 58.8% of cases, whereas a prosthetic graft was used in 35.1% of cases. The most common bypass origin was the femoral artery (94.1%), and target was the popliteal artery (70.1%). Significant differences between Monday-Tuesday versus Wednesday-Friday, respectively, were mean body mass index (27.8 kg/m² vs. 28 kg/m²), preoperative aspirin use (74.2% vs. 72.5%), continuous vein harvest technique (41.9% vs. 44%), and mean operative time (mins) (216.2 vs. 222.6) (all P < 0.05). Univariate postoperative outcomes were significantly different between Monday-Tuesday versus Wednesday-Friday, respectively, for mean length of stay (LOS) (days) (3.9 vs. 4.3), cardiac complications (myocardial infarction/dysrhythmia/congestive heart failure) (3.5% vs. 4.9%), stroke (0.3% vs. 0.6%), and respiratory complications (0.8% vs. 1.3%) (all P < 0.05). Multivariable analysis demonstrated that LEBs performed on Wednesday-Friday versus Monday-Tuesday for claudication/rest pain were independently associated with cardiac complications and prolonged LOS. There were also 8,491 LEBs performed for tissue loss which overall had similar findings to LEBs performed for claudication/rest pain such as increased LOS for LEBs performed for tissue loss on Wednesday-Friday (P < 0.001) and similar likeliness for respiratory complication, wound complication, return to the operating room, and mortality (all P > 0.05). However, LEBs performed for tissue loss on Wednesday-Friday versus Monday-Tuesday had similar cardiac complications (P > 0.05).

CONCLUSIONS

Elective LEBs performed on later weekdays for claudication/rest pain were associated with cardiac complications and prolonged LOS, whereas tissue loss confirmed association with prolonged LOS. Further investigations are needed to identify whether increased resources or allocation of resources should be focused on later weekdays to optimize patient outcomes.

Quantifying the risk-adjusted hospital costs of postoperative complications after lower extremity bypass in patients with claudication

OBJECTIVE

Increasing evidence has shown that the risks associated with surgical revascularization for intermittent claudication outweigh the benefits. The aim of our study was to quantify the cost of care associated with perioperative complications after elective lower extremity bypass (LEB) in patients presenting with intermittent claudication.

METHODS

All patients undergoing first-time LEB for claudication in the Healthcare Database (2009-2015) were included. The primary outcome was in-hospital postoperative complications, including major adverse limb events (MALE), major adverse cardiac events (MACE), acute kidney injury, and wound complications. The overall crude hospital costs are reported, and a generalized linear model with log link and inverse Gaussian distribution was used to calculate the predicted hospital costs for specific complications.

RESULTS

Overall, 7154 patients had undergone elective LEB for claudication during the study period. The median age was 66 years (interquartile range, 59-73 years), 67.5% were male, and 75.3% were white. Two thirds of patients (61.2%) had Medicare insurance, followed by private insurance (26.9%), Medicaid (7.7%), and other insurance (4.2%). In-hospital complications occurred in 8.5% of patients, including acute kidney injury in 3.0%, MALE in 2.8%, wound complications in 2.3%, and MACE in 1.0%. The overall median crude hospital cost was $11,783 (interquartile range, $8911-$15,767) per patient. The incremental increase in cost associated with a postoperative complication was significant, ranging from $6183 (95% confidence interval, $4604-$7762) for MALE to $10,485 (95% confidence interval, $6529-$14,441) for MACE after risk adjustment.

CONCLUSIONS

Postoperative complications after elective LEB for claudication are not uncommon and increase the in-hospital costs by 46% to 78% depending on the complication. Surgical revascularization for claudication should be used sparingly in carefully selected patients.

Unplanned readmissions after endovascular intervention or surgical bypass for critical limb ischemia

OBJECTIVE

After surgery or other interventions, unplanned readmissions are associated with poor outcomes and drain health care resources. Patients with critical limb ischemia (CLI) are at particularly high risk of readmission, and readmissions result in increased health care costs. The primary aims of the study were to discover and compare the 30-day readmission rates of patients who underwent lower extremity surgical bypass (LEB) and endovascular infrainguinal endovascular intervention (IEI) for CLI and to evaluate the relationship between unplanned readmissions likely related to the primary procedure for IEI compared with LEB.

METHODS

The Targeted Vascular Module from the American College of Surgeons National Surgical Quality Improvement Program was queried to identify all infrainguinal LEB or IEI for CLI from 2015 to 2018. Those who were not eligible for the primary outcome of interest were excluded. The primary 30-day outcome was unplanned readmission. Univariate analyses for primary and secondary outcomes were performed using Fisher's exact and Wilcoxon rank-sum testing. Multivariate analysis was performed using inverse probability weighting and independent risk factors for readmission were identified with logistic regression.

RESULTS

There were 12,873 patients who met inclusion criteria. In the LEB cohort, there were 7270 (56.5%) patients, and in the IEI cohort, there were 5603 (43.5%) patients. Thirty percent (n = 1696) of the IEI cohort underwent a tibial intervention, and 49% (n = 3547) underwent a distal bypass. The IEI cohort was more likely to be high physiologic risk (P < .001) and to present with tissue loss (P < .001), whereas the LEB cohort was more likely to have high anatomic risk features (P < .001) and be performed under emergent conditions (P < .001). After multivariable analysis, LEB was found to be independently predictive for both unplanned readmissions due to any cause (adjusted odds ratio, 1.35; 95% confidence interval, 1.22-1.51; P < .001) and procedure-related unplanned interventions (adjusted odds ratio, 1.85; 95% confidence interval, 1.63-2.11; P < .001). Independent predictors of readmission were LEB, preoperative sepsis, severe chronic kidney disease, dependent functional status, insulin-dependent diabetes mellitus, high-risk physiologic features, African American race, preoperative steroid use, history of severe chronic obstructive pulmonary disease, and preoperative tissue loss.

CONCLUSIONS

LEB is independently associated with unplanned readmission from all causes and from procedure-related causes after adjusting for the measured confounders. More research is required to determine the economic burden of these readmissions.

Thirty-Day Readmissions After Carotid Artery Stenting Versus Endarterectomy: Analysis of the 2013-2014 Nationwide Readmissions Database

BACKGROUND

Contemporary, nationally representative 30-day readmissions data after carotid artery stenting (CAS) and carotid endarterectomy (CEA) are lacking.

METHODS

Patients undergoing CAS or CEA were identified from the 2013 to 2014 Nationwide Readmissions Databases. Propensity matching was used to balance baseline clinical characteristics. Thirty-day nonelective readmission rates, length of stay, and causes of readmission were compared.

RESULTS

Overall, 85 337 (national estimate of 194 332) patients were identified before propensity score matching, 11 490 (13.4%) of whom underwent CAS and 73 847 (86.6%) of whom underwent CEA. Crude 30-day readmission rates were higher for patients treated with CAS than CEA (8.3% versus 6.8%; P<0.001), but these differences were negated in the propensity-matched cohort (n=22 214; 8.4% versus 7.9%, P=0.20), and readmission length of stay was longer for CEA than CAS (2 versus 1 day, respectively; P=0.002). The most common reasons for readmission were neurological and cardiac events; readmission reasons varied by revascularization modality. Readmission due to a stroke or transient ischemic attack was more common among patients treated with CAS than CEA (1.2% versus 0.9%; P=0.042), while readmission for procedural or medical complications occurred more often following CEA than CAS (1.1% versus 0.5%; P<0.001); readmission rates for cardiac causes were similar between groups.

CONCLUSIONS

Less than 8% of patients are readmitted within 30 days of a carotid revascularization procedure. After adjusting for baseline differences, readmission rates are similar for CAS and CEA although readmission length of stay is longer after the latter. Readmission for neurological causes was more common following CAS while readmission for procedural or medical complications occurred more often following CEA. Higher annual institutional CEA volumes were associated with lower risk for 30-day readmission; in contrast, institutional CAS volumes were not related to readmission risk. These data provide important insights into the short-term, outcomes of patients following carotid artery revascularization.

A systematic review and meta-analysis of risk factors for and incidence of 30-day readmission after revascularization for peripheral artery disease

OBJECTIVE

Readmission to the hospital after revascularization for peripheral artery disease (PAD) is frequently reported. No consensus exists as to the exact frequency and risk factors for readmission. This review aimed to determine the incidence of and risk factors for 30-day readmission after revascularization for PAD.

METHODS

PubMed/Medline (Ovid), Scopus, Web of Science, the Cochrane Library, and CINAHL were searched systematically from inception until May 20, 2018. Studies were eligible for inclusion if they included patients with diagnosed PAD undergoing revascularization and reported the readmission rate and a statistical evaluation of the association of at least one risk factor with readmission. Studies were excluded if data for other procedures could not be distinguished from revascularization. Two authors undertook study selection independently with the final inclusion decision resolved through consensus. The PRISMA and Meta-analyses of Observational Studies in Epidemiology guidelines were followed regarding data extraction and quality assessment, which was performed by two authors independently. Data were pooled using a random effects model.

RESULTS

The primary outcome was readmission within 30 days of revascularization. Fourteen publications reporting the outcomes of 526,008 patients were included. Reported readmission rates ranged from 10.9% to 30.0% with a mean of 16.4% (95% confidence interval [CI], 15.1%-17.9%). Meta-analyses suggested the following risk factors had a significant association with readmission: female sex (odds ratio [OR], 1.13; 95% CI, 1.05-1.21), black race (OR, 1.36; 95% CI, 1.28-1.46), dependent functional status (OR, 1.72; 95% CI, 1.43-2.06), critical limb ischemia (OR, 2.12; 95% CI, 1.72-2.62), emergency admission (OR, 1.75; 95% CI, 1.43-2.15), hypertension (OR, 1.39; 95% CI, 1.26-1.54), heart failure (OR, 1.82; 95% CI, 1.50-2.20), chronic pulmonary disease (OR, 1.19; 95% CI, 1.08-1.32), diabetes (OR, 1.47; 95% CI, 1.32-1.63), chronic kidney disease (OR, 1.93; 95% CI, 1.62-2.31), dialysis dependence (OR, 2.08; 95% CI, 1.75-2.48), smoking (OR, 0.83; 95% CI, 0.78-0.89), postoperative bleeding (OR, 1.70; 95% CI, 1.23-2.35), and postoperative sepsis (OR, 4.13; 95% CI, 2.02-8.47).

CONCLUSIONS

Approximately one in six patients undergoing revascularization for PAD are readmitted within 30 days of their procedure. This review identified multiple risk factors predisposing to readmission, which could potentially serve as a way to target interventions to reduce readmissions.

Perioperative Outcomes of Lower Extremity Revascularization for Rest Pain and Tissue Loss

BACKGROUND

Critical limb ischemia (CLI) is the clinical manifestation of severe peripheral artery disease presenting as rest pain (RP) and tissue loss (TL). Most studies compare CLI as a homogenous group with claudication with limited database studies specifically studying these differences. We hypothesize that CLI should be stratified into RP and TL because of significant differences in disease severity, comorbidities, and outcomes.

METHODS

The American College of Surgeons National Surgical Quality Improvement Program database from 2012 to 2016 was reviewed. All patients with a postoperative diagnosis of CLI undergoing femoral to popliteal bypass (FPB) with vein or graft were identified. Patients were stratified into cohorts based on International Classification of Disease (ICD)-9 or ICD-10 codes for RP or TL (gangrene or ulcer). Univariate and multivariate analyses were performed to examine 30-day mortality, morbidity, major amputation, and readmission adjusting for demographics, comorbidities, and procedural details.

RESULTS

There were 5,304 patients. Compared to RP, patients with TL were older (P < 0.0001) and more likely to be dependent (P < 0.0001). TL patients were also more likely to have diabetes (P < 0.0001), congestive heart failure (P < 0.0001), renal failure (P = 0.004), dialysis (P < 0.0001), history of wound infection (P < 0.0001), and sepsis (P < 0.0001). TL patients had higher American Society of Anesthesiologists class (P < 0.0001), were less likely to be transferred from home (P < 0.0001), and more likely to receive an FPB with vein (P = 0.03). Patients with TL had worse perioperative outcomes compared with RP in terms of pneumonia (P = 0.004), unplanned intubation (P = 0.009), cardiac arrest requiring cardiopulmonary resuscitation (P = 0.003), bleeding requiring transfusions (P < 0.0001), sepsis (P < 0.0001), septic shock (P = 0.02), and reoperation (P < 0.0001). TL was associated with significantly higher 30-day morbidity (P < 0.0001), 30-day mortality (P < 0.0001), major amputation (P = 0.0004), and readmission rates (P = 0.005). Patients with TL compared with those with RP also had longer hospital stays (P < 0.0001) and days between operation to discharge (P < 0.0001). TL was independently associated with increased 30-day morbidity (OR: 1.16 [1.00-1.35]) and major amputation (OR: 2.48 [1.29-4.76]) compared with RP.

CONCLUSIONS

Patients with RP and TL have drastic differences that impact perioperative mortality and readmissions. TL is an independent predictor of 30-day morbidity and major amputation. The stratification of CLI into RP and TL can provide insight into variations in outcomes and provide a means to quantify the risks associated with the 2 manifestations of the disease.

One-Year Readmission after Open and Endovascular Revascularization for Critical Limb Ischemia

BACKGROUND

Lower extremity revascularization for critical limb ischemia (CLI) remains a subject of clinical equipoise. Readmissions and repeat lower extremity revascularization increase the cost of care and decrease the value of initial treatment. This study examines readmissions and repeat inpatient revascularization and major amputation up to 1 year after initial open and endovascular lower extremity revascularization.

METHODS

The 2014 Nationwide Readmissions Database (NRD) was reviewed. The NRD provides all subsequent readmissions of any hospitalization for the calendar year. A cohort of patients undergoing lower extremity revascularization in January only was selected based on International Classification of Diseases, Ninth Revision, Clinical Modification codes. Patients were divided into open and endovascular groups. Readmissions for repeat lower extremity revascularization (RFR) were identified based on procedural codes. Open and endovascular lower extremity revascularization were compared in terms of patient characteristics as well as readmissions, RFR, major amputation, and inpatient mortality at 1 year. Risk-adjusted outcomes accounting for differences in age, gender, income, and Charlson Comorbidity Index (CCI) were derived using regression analysis.

RESULTS

There were 1,668 open and 1,410 endovascular lower extremity revascularizations. Patients in the endovascular group were significantly older (P < 0.01), more likely to be women (P < 0.01), and had higher CCI (P < 0.01). Patients undergoing endovascular lower extremity revascularization had significantly higher readmission rate (49 vs. 33.7, P < 0.01) and higher mortality (10.4 vs. 5.3, P < 0.01). Readmitted patients after endovascular lower extremity revascularization had significantly higher mean number of repeat readmissions compared to open lower extremity revascularization (2.49 ± 0.12 vs. 2.13 ± 0.08, P = 0.01). There was no difference in RFR (P = 0.82) or major amputation (P = 0.19). Open revascularization was independently associated with decreased readmission (odds ratio = 0.55 [0.43-0.71]) compared to endovascular. However, there was no significant association between the type of lower extremity revascularization and major amputation or RFR.

CONCLUSIONS

Endovascular lower extremity revascularization for CLI is performed on older and sicker patients and seems to be associated with increased readmission at 1 year compared to open lower extremity revascularization. Regardless of the initial modality of treatment, patients are likely to undergo at least 1 revascularization during readmissions.

Analysis of Thirty-Day Readmission after Infrainguinal Bypass

BACKGROUND

The Vascular Study Group of New England (VSGNE) conducted a pilot study evaluating the feasibility of 30-day data collection in patients undergoing infrainguinal bypass (INFRA) which was subsequently expanded to include a limited number of additional sites within the Vascular Quality Initiative (VQI). The purpose of our study was to use these data to evaluate the incidence of 30-day readmission after infrainguinal bypass. A secondary goal of the study was to perform a critical appraisal of the data elements and definitions in the 30-day dataset.

METHODS

All infrainguinal bypass procedures performed during the pilot study period (7/2008 and 4/2016) were identified and merged with a dataset containing the 30-day data. Incidence and types of readmission were assessed. The primary endpoint was 30-day readmission, defined as any hospital readmission within 30 days of index operation; unplanned 30-day readmission was the secondary endpoint. Covariates tested for association with the primary and secondary endpoints included patient demographics, comorbidities, procedural, and postoperative characteristics. Variables significant on univariate screen (P < 0.2) were evaluated with logistic regression to identify independent determinants.

RESULTS

Of 9,847 infrainguinal bypass patients, 5,842 (59%) patients were identified with 30-day data, and 907 (16%) were readmitted within 30 days. Of readmissions, 675 (85%) were unplanned. Potentially modifiable independent determinants of any 30-day readmission included 30-day surgical site infection (SSI) (odds ratio [OR]: 10, 95% confidence interval [CI]: 8.2-12, P < 0.0001), postoperative acute kidney injury (OR: 1.7, 95% CI: 1.2-2.5, P = 0.002), and discharge anticoagulation (OR: 1.2, 95% CI: 1.04-1.5; P = 0.02). Predictors of unplanned 30-day readmission were very similar but identified in-hospital major amputation as an additional independent predictor (OR: 2.8, 95% CI: 1.6-4.9, P = 0.0002).

CONCLUSIONS

This study demonstrates the interest in, and value of, 30-day data collection in VSGNE/VQI and documents the frequency of readmission after infrainguinal bypass. Readmission within 30 days is strongly associated with SSI, stressing the importance of efforts to decrease this complication. Given that many other predictors are unmodifiable, 30-day readmission is only appropriate as a quality metric if it is risk adjusted using large, real-world datasets such as VQI. Lessons learned from this analysis can be used to select optimal 30-day data elements.

The burden of critical limb ischemia: a review of recent literature

Peripheral arterial disease is a chronic vascular disease characterized by impaired circulation to the lower extremities. Its most severe stage, known as critical limb ischemia (CLI), puts patients at an increased risk of cardiovascular events, amputation, and death. The objective of this literature review is to describe the burden of disease across a comprehensive set of domains—epidemiologic, clinical, humanistic, and economic—focusing on key studies published in the last decade. CLI prevalence in the United States is estimated to be approximately 2 million and is likely to rise in the coming years given trends in important risk factors such as age, diabetes, and smoking. Hospitalization for CLI patients is common and up to 60% are readmitted within 6 months. Amputation rates are unacceptably high with a disproportionate risk for certain demographic and socioeconomic groups. In addition to limb loss, CLI patients also have reduced life expectancy with mortality typically exceeding 50% by 5 years. Given the poor clinical prognosis, it is unsurprising that the quality of life burden associated with CLI is significant. Studies assessing quality of life in CLI patients have used a variety of generic and disease-specific measures and all document a substantial impact of the disease on the patient’s physical, social, and emotional health status compared to population norms. Finally, the poor clinical outcomes and increased medical resource use lead to a considerable economic burden for national health care systems. However, published cost studies are not comprehensive and, therefore, likely underestimate the true economic impact of CLI. Our summary documents a sobering assessment of CLI burden—a poor clinical prognosis translating into diminished quality of life and high costs for millions of patients. Continued prevention efforts and improved treatment strategies are the key to ameliorating the substantial morbidity and mortality associated with this disease.

Nationally Representative Readmission Factors Associated with Endovascular versus Open Repair of Abdominal Aortic Aneurysm

BACKGROUND

Hospital readmissions are tied to financial penalties and thus significantly influence health-care policy. Many current studies on readmissions lack national representation by not tracking readmissions across hospitals. The recently released Nationwide Readmission Database is one of the most comprehensive national sources of readmission data available, making it an invaluable resource to understand this critically important health policy issue.

METHODS

The Nationwide Readmission Database for 2013 and 2014 was queried for adult patients with abdominal aortic aneurysm (441.4) undergoing endovascular (39.71) or open (38.44) repair. Outcomes examined were overall/initial admission mortality and overall/30-day readmissions. Multivariate logistic regression for these outcomes was also performed on multiple readmission factors.

RESULTS

Fifty-three thousand four hundred seventeen patients underwent abdominal aortic aneurysm repair (47,431 endovascular aortic repair [EVAR] versus 5,986 open surgical repair [OSR]). Significant differences were found for EVAR versus OSR on overall readmissions, initial admission cost, readmission costs, length of stay, days to readmission, and overall/initial admission mortality. Multivariate logistic regression analysis found that length of stay > 30, Charlson Comorbidity Index > 1, discharge disposition, and female sex were all significant predictors of 30-day readmission. Repair type was significantly associated with 30-day readmissions; however, it was not a significant factor for overall readmissions.

CONCLUSION

There are significant differences in costs, prognosis, and readmission rates for EVAR versus OSR. Given that these differences are being used to create "acceptable" readmission rates, disbursement quotas among hospitals, and subsequent penalties for providers outside the expected rates, it is only prudent to obtain the most accurate information to guide those policies.

LEVEL OF EVIDENCE

Care management/epidemiological, level IV.

Nationally Representative Readmission Factors in Patients with Claudication and Critical Limb Ischemia

BACKGROUND

Hospital readmissions are associated not only with increased mortality, morbidity, and costs but also, with current health-care reform, tied to significant financial and administrative penalties. Some studies show that patients undergoing vascular surgery may have higher than average readmission rates. The recently released Nationwide Readmission Database (NRD) is the most comprehensive national source of readmission data, gathering discharge information from 22 geographically dispersed states, accounting for 51.2% of the total U.S. resident population and 49.3% of all U.S. hospitalizations. The aim of this study is to use the power of the NRD and obtain nationally representative readmission information for patients admitted with claudication or critical limb ischemia (CLI) who underwent revascularization procedures.

METHODS

The NRD was queried for all patients admitted for claudication (International Classification of Diseases Ninth Revision [ICD-9] 440.21) or CLI (ICD-9 440.22-440.24) and who underwent percutaneous transluminal angioplasty, peripheral bypass, or aortofemoral bypass. Patient demographics, comorbidities, length of stay (LOS), mortality, readmission rates, and associated costs were collected. Univariable and multivariable logistic regression analysis was implemented on claudication and CLI groups on all outcomes of interest. The most common readmission diagnosis codes and diagnosis groups were also identified.

RESULTS

A total of 92,769 patients were admitted for peripheral vascular disease (33,055 with claudication and 59,714 with CLI). The 30-day readmission/any readmission rate was 8.97%/21.49% and 19.26%/40.36%, for claudication and CLI, respectively. Significant differences were found for claudication and CLI, respectively, on initial cost of admission ($18,548 vs. $29,148, P < 0.001), readmission costs ($14,726 vs. $17,681 P < 0.001), LOS (4 days vs. 9 days, P < 0.001), days to readmission (73 days vs. 59 days, P < 0.001), mortality during initial admission (256 vs. 1,363, P < 0.001), and mortality during any admission (538 vs. 3,838, P < 0.001). Univariate and multivariate logistic regression analysis found that claudication, CLI, angioplasty, peripheral bypass, aortofemoral bypass, female sex, age >65, Charlson Comorbidity Index, LOS, and primary expected payer status were all significant predictors of 30-day and overall readmissions at varying degrees. The 5 most common disease readmission groups found were other vascular procedures (12.6%), amputation of lower limb except toes (6.3%), sepsis (5.4%), heart failure (4.9%) and postoperative or other device infections (4.8%). Of the abovementioned groups, the 4 most common diagnoses included "other postoperative infections," sepsis, atherosclerosis of native arteries with gangrene, and "other complications due to other vascular device, implant, or graft."

CONCLUSIONS

Our results demonstrate that there is a significant difference in readmission rates, cost, and morbidity between patients admitted for claudication and CLI. Furthermore, based on regression analysis, there are multiple other clear risk factors associated with worse clinical and economic outcomes. Further study is needed to predict which patients will require increased vigilance during their hospital stay to prevent readmissions and worse outcomes.

LEVEL OF EVIDENCE

Care management/epidemiological, level IV.

Treating Peripheral Artery Disease in the Wake of Rising Costs and Protracted Length of Stay

BACKGROUND

There has been growing scrutiny in the treatment of patients with peripheral artery disease due to the utilization of resources to manage this complex patient population. The purpose of this study was to determine the factors associated with prolonged length of stay (LOS > 7 days) following lower extremity bypass using data from the Vascular Quality Initiative as well as to define the additional costs incurred due to prolonged LOS in our health system.

METHODS

Summary statistics were performed of patients undergoing lower extremity bypass from 2010 to 2015. Student's t-tests and χ² tests were performed to compare those with and without prolonged LOS. Multivariable logistic regression was then performed to determine the independent predictors for increased LOS. We then compared our institutional LOS with that of representative institutions from the University Health System Consortium and evaluated the impact of prolonged LOS on limb salvage and survival.

RESULTS

This study included 334 patients with a mean age of 66.4 ± 12.4 years, 64.7% males, 58.5% of white race, 11.1% on dialysis, 80.5% smokers, and 53.6% with diabetes. The mean LOS was 15.7 ± 12.2 days. Prolonged LOS was associated with transfer (15.4% vs. 2.3%, P = 0.001), diabetes (58.3% vs. 40.2%, P = 0.004), critical limb ischemia (71.3% vs. 49.4%, P < 0.001), preoperative need for ambulatory assistance (44.5% vs. 16.1%, P < 0.001), prior ipsilateral bypass (6.9% vs. 1.1%, P = 0.042), urgent surgery (39.7% vs. 9.8%, P < 0.001), tibial or distal target vessel (52.7% vs. 28.0%, P < 0.001), use of vein (65.4% vs. 46.3%, P = 0.002), return to operating room (42.6% vs. 1.2%, P < 0.001), ambulatory assistance (65.0% vs. 34.1%, P < 0.001) as well as discharge anticoagulant (22.8% vs. 9.8%, P = 0.010). Multivariable logistic regression identified urgency (odds ratio [OR] = 5.09, 95% confidence interval [CI] 2.16-12.02, P < 0.001), critical limb ischemia (OR = 3.12, 95% CI 1.65-5.90, P < 0.001), return to OR (OR = 40.30, 95% CI 5.36-303.20, P < 0.001), use of vein (OR = 2.19, 95% CI 1.18-4.07, P = 0.013), and the need for anticoagulation at discharge (OR = 2.56, 95% CI 1.03-6.33, P = 0.043) as independent predictors of LOS > 7 days. Prolonged hospital stays accounted for an additional $40,561.64 in total cost and $26,028 in direct costs incurred. Despite these increased costs, limb salvage and overall survival were not adversely impacted in the prolonged LOS group in follow-up.

CONCLUSIONS

Lower extremity bypass is associated with a longer than expected LOS in our health system, much of which can be attributed to return to the OR for minor amputations and wound issues. This led to added total and direct costs, where the majority of this increase was attributable to prolonged LOS. Limb salvage and overall survival were preserved, however, in this subset of patients in follow-up. These findings suggest that lower extremity bypass patients are a resource-intensive population of patients, but that these costs are worthwhile in the setting of preserved limb salvage and overall survival.

Short- and long-term readmission rates after infrainguinal bypass in a safety net hospital are higher than expected

OBJECTIVE

Readmission rates are expected to have an increasing effect on both the hospital bottom line and physician reimbursements. Safety net hospitals may be most vulnerable. We examined readmissions at 30 days, 90 days, and 1 year in a large safety net hospital to determine the magnitude and effect of short- and long-term readmission rates after lower extremity infrainguinal bypass in this setting.

METHODS

All nonemergent extremity infrainguinal bypass performed at a large safety net hospital between 2008 and 2016 were identified. Patient demographic, social, clinical, and procedural details were extracted from the electronic medical record. An analysis of patients readmitted at 30 days, 90 days, and 1 year was completed to determine the details of the readmission.

RESULTS

A total of 350 patients undergoing extremity infrainguinal bypass were identified. The most frequent indication was tissue loss (57%), followed by claudication (25.6%), and rest pain (17.4%). Patient insurance carriers included Medicare (61.7%), Medicaid (25.4%), and private (13%). The distal target was the popliteal and tibial artery in 52.6% and 47.4% cases, respectively. The majority of bypasses used autologous vein (73.1%). In-hospital complications included pulmonary complications (4.3%), urinary tract infection (3.1%), acute renal failure (2%), graft occlusion (2%), myocardial infarction (1.7%), bleeding (1.4%), surgical wound complications (1.1%), and stroke (0.9%). The 30-day readmission rate was 30% with the most common reasons for readmission being surgical wound complications, nonsurgical foot/leg wounds, nonextremity infectious causes, cardiac ischemia, and congestive heart failure. The 90-day readmission rate was 49.4% and the most common reasons for readmission from 31 to 90 days were nonsurgical foot/leg wounds, graft complications, surgical wound complications, cardiac ischemia, and contralateral leg morbidity. The readmission rate within 1 year was 72.2%. Readmission causes from 91 days to 1 year included graft complications, contralateral leg morbidity, nonextremity infectious, nonsurgical foot/leg wounds, cardiac ischemia, and congestive heart failure. A tibial bypass target was associated with 30-day (odds ratio [OR], 1.69; 95% confidence interval [CI], 1.06-2.69; P = .029) and 90-day (OR, 1.77; 95% CI, 1.14-2.74, P = .011) readmission. Nonprivate insurance (OR, 2.31; 95% CI, 1.17-4.57, P = .016), and critical limb ischemia (OR, 1.77; 95% CI, 1.14-2.74; P = .035) were associated with 1-year readmission.

CONCLUSIONS

Short- and long-term readmission rates in a safety net setting are high. The 30-day rates in this study are higher than historically reported. This data sets baseline rates for 90-day and 1-year readmission for future analyses. Although the majority of short-term readmissions are related to the index procedure, long-term readmission rates are more frequently related to systemic comorbidities. Targeted patient interventions aimed at preventing the most common reasons for readmission may improve readmission rates, particularly among patients with nonprivate insurance. However, other risk factors, such as tibial target, may not be modifiable and a higher readmission rate may need to be accepted in this population.

Thirty-Day Readmissions After Endovascular or Surgical Therapy for Critical Limb Ischemia

Background:

Thirty-day readmission rates have gained increasing importance as a key quality metric. A significant number of patients are hospitalized for the management of critical limb ischemia (CLI), but limited data are available on the incidence, predictors, and causes of 30-day readmission after hospitalization for CLI.

Methods:

Hospitalizations for a primary diagnosis of CLI during which patients underwent endovascular or surgical therapy (revascularization and/or amputation) and were discharged alive were identified in the 2013 to 2014 Nationwide Readmissions Databases. Incidence, reasons, and costs of 30-day unplanned readmissions were determined. Hierarchical logistic regression models were used to identify independent predictors of 30-day readmissions.

Results:

We included 60 998 (national estimate, 135 110) index CLI hospitalizations (mean age, 68.9±11.9 years; 40.8% women; 24.6% for rest pain, 37.2% for ulcer, and 38.2% for gangrene). The 30-day readmission rate was 20.4%. Presentation with ulcer or gangrene, age ≥65 years, female sex, large hospital size, teaching hospital status, known coronary artery disease, heart failure, diabetes mellitus, chronic kidney disease, anemia, coagulopathy, obesity, major bleeding, acute myocardial infarction, vascular complications, and sepsis were identified as independent predictors of 30-day readmission. Mode of revascularization was not independently associated with readmissions. Infections (23.5%), persistent or recurrent manifestations of peripheral artery disease (22.2%), cardiac conditions (11.4%), procedural complications (11.0%), and endocrine issues (5.7%) were the most common reasons for readmission. The inflation-adjusted aggregate costs of 30-day readmissions for CLI during the study period were $624 million.

Conclusions:

Approximately 1 in 5 patients hospitalized for CLI and undergoing revascularization is readmitted within 30 days. Risk of readmission is influenced by CLI presentation, patient demographics, comorbidities, and in-hospital complications, but not by the mode of revascularization.

Risk Factors for 30-Day Hospital Re-Admission with an Infectious Complication after Lower-Extremity Vascular Procedures

BACKGROUND

Lowering the 30-d re-admission rate after vascular surgery offers the potential to improve healthcare quality. This study evaluated re-admission associated with infections after open and endovascular lower extremity (LE) procedures for peripheral artery disease (PAD).

METHODS

Patients admitted for elective LE procedures for PAD were selected from the Cerner Health Facts^® database. Chi-square analysis evaluated the characteristics of the index admission associated with infection at 30-d re-admission. Multivariable logistic models were created to examine the association of patient and procedural characteristics with infections at re-admission. The microbiology data available at the time of re-admission were evaluated also.

RESULTS

A total of 7,089 patients underwent elective LE procedures, of whom 770 (10.9%) were re-admitted within 30 d. A total of 289 (37.5%) had a diagnosis of infection during the re-admission. These infections included surgical site (14.8%), cellulitis (13.6%), sepsis (8.8%), urinary tract (4.9%), and pneumonia (4.9%). Index stay factors associated with infection at re-admission were fluid and electrolyte disorders, kidney disease, diabetes, previous infection, and chronic anemia. Laboratory results associated with an infection during re-admission were post-operative hemoglobin <8 g/dL, blood urea nitrogen >20 mg/dL, platelet counts >400 × 10³/mcL, glucose >180 mg/dL, and white blood cell count >11.0 × 10³/mcL. Adjusted models demonstrated longer stay, chronic anemia, previous infection, treatment at a teaching hospital, and hemoglobin <8 g/dL to be risk factors for re-admission with infection. Infective organisms isolated during the re-admission stay included Staphylococcus, Enterococcus, Escherichia, Pseudomonas, Proteus, and Klebsiella.

CONCLUSIONS

Infectious complications were associated with more than one-third of all re-admissions after LE procedures. Predictors of re-admission within 30 d with an infectious complication were longer stay, greater co-morbidity burden, hospitalization in teaching facilities, hemoglobin <8 g/dL, and an infection during the index stay. Microbiology examination at re-admission demonstrated gram-negative bacteria in more than 40% of infections. Further evaluation of high-risk vascular patients prior to discharge and consideration of antibiotic administration for gram-negative organisms at the time of re-admission may improve outcomes.