Trends in hospital treatments for peripheral arterial disease in the United States and association between payer status and quality of care/outcomes, 2007-2011

Geographic Region and Insurance Status Predict Access to Salvage Procedures for Diabetic Lower-Extremity Wounds in the United States

PURPOSE

The current study assessed factors associated with limb salvage and subsequent amputations for patients with diabetic lower-extremity wounds in the United States.

METHODS

Using national administrative data from 2010 to 2022 (PearlDiver), adults undergoing amputation or salvage procedures (skin graft, local flap, or free flap) for diabetic lower-extremity wounds were identified. Patient age, sex, Elixhauser Comorbidity Index, geographic region, and insurance status were extracted. Insulin dependence, tobacco use, end-stage renal disease, peripheral vascular disease, prior amputation, preoperative lower-extremity infection, and preoperative vascular testing or intervention were also extracted. Subsequent amputations following limb salvage were identified. Factors associated with salvage procedures and subsequent amputation were analyzed with multivariable logistic regression.

RESULTS

The final cohorts included 97,472 patients with amputation and 62,850 patients with salvage. The average follow-up was 3.9 years. Many patient and clinical factors were associated with limb salvage. Most notably, patients in the Northeast had the greatest odds of undergoing salvage, and relative to privately insured patients, those with Medicare and Medicaid were significantly less likely to undergo salvage. Of patients who underwent salvage, 11,595 (18%) underwent subsequent amputation at an average time of 1.7 years. There was minimal variation in subsequent amputation by geographic region, and patients with Medicare and Medicaid were only slightly more likely to undergo a subsequent amputation.

CONCLUSIONS

There are significant disparities in access to limb salvage procedures in the United States based on region and insurance status despite only minor differences in progression to subsequent amputation for these patients.

Mapping the blueprint of artificial blood vessels research: a bibliometric analysis

BACKGROUND

Vascular diseases represent a significant cause of disability and death worldwide. The demand for artificial blood vessels is increasing due to the scarce supply of healthy autologous vessels. Nevertheless, the literature in this area remains sparse and inconclusive.

METHODS

Bibliometrics is the study of quantitative analysis of publications and their patterns. This study conducts a bibliometric analysis of publications on artificial blood vessels in the 21st century, examining performance distribution, research trajectories, the evolution of research hotspots, and the exploration of the knowledge base. This approach provides comprehensive insights into the knowledge structure of the field.

RESULTS

The search retrieved 2060 articles, showing a consistent rise in the publication volume and average annual citation frequency related to artificial blood vessels research. The United States is at the forefront of high-quality publications and international collaborations. Among academic institutions, Yale University is a leading contributor. The dominant disciplines within the artificial blood vessels sector include engineering, biomedical sciences, materials science, biomaterials science, and surgery, with surgery experiencing the most rapid expansion.

CONCLUSIONS

This study is the inaugural effort to bibliometrically analyze and visualize the scholarly output in the domain of artificial blood vessels. It provides clinicians and researchers with a reliable synopsis of the field's current state, offering a reference point for existing research and suggesting new avenues for future investigations.

Outcomes for Patients with Diabetic Foot Ulcers Following Transition from Medicaid to Commercial Insurance

Objective

This study investigates the outcomes of Medicaid beneficiaries with diabetic foot ulcers (DFUs) who had transitioned to commercial insurance.

Methods

We utilized the PearlDiver claims database to identify adult patients diagnosed with a new DFU between 2010 and 2019. The study cohort comprised 8856 Medicaid beneficiaries who had at least three years of continuous enrollment after DFU diagnosis. Medicaid beneficiaries who transitioned to Medicare during follow-up were excluded. Adjusted comparisons of outcomes were performed by propensity matching the two groups for age, gender, and Charlson Comorbidity Index (CCI) in a 1:1 ratio. We used logistic regression and Kaplan-Meier estimate to evaluate the association between insurance change (from Medicaid to commercial insurance) and major amputation.

Results

Among the 8856 Medicaid beneficiaries with DFUs, 66% (n = 5809) had transitioned to commercial insurance coverage during follow-up. The overall major amputation rate was 2.8% (n = 247), with a lower rate observed in patients who transitioned to commercial insurance compared to those with continuous Medicaid coverage (2.6% vs. 3.2%, p < 0.05). In multivariable analysis, Medicaid beneficiaries who transitioned to commercial insurance had a 27% lower risk of major amputation (study cohort: odds ratios [OR] 0.75, 95% CI 0.56-0.97, p = 0.03; matched cohort: OR 0.65, 95% 0.22, 0.55, p = 0.01) compared to those with continuous Medicaid coverage.

Conclusions

Transitioning from Medicaid to commercial insurance may be associated with a lower risk of major amputation among Medicaid beneficiaries with DFUs.

Artificial Intelligence of Arterial Doppler Waveforms to Predict Major Adverse Outcomes Among Patients Evaluated for Peripheral Artery Disease

BACKGROUND

Patients with peripheral artery disease are at increased risk for major adverse cardiac events, major adverse limb events, and all-cause death. Developing tools capable of identifying those patients with peripheral artery disease at greatest risk for major adverse events is the first step for outcome prevention. This study aimed to determine whether computer-assisted analysis of a resting Doppler waveform using deep neural networks can accurately identify patients with peripheral artery disease at greatest risk for adverse outcome events.

METHODS AND RESULTS

Consecutive patients (April 1, 2015, to December 31, 2020) undergoing ankle-brachial index testing were included. Patients were randomly allocated to training, validation, and testing subsets (60%/20%/20%). Deep neural networks were trained on resting posterior tibial arterial Doppler waveforms to predict major adverse cardiac events, major adverse limb events, and all-cause death at 5 years. Patients were then analyzed in groups based on the quartiles of each prediction score in the training set. Among 11 384 total patients, 10 437 patients met study inclusion criteria (mean age, 65.8±14.8 years; 40.6% women). The test subset included 2084 patients. During 5 years of follow-up, there were 447 deaths, 585 major adverse cardiac events, and 161 MALE events. After adjusting for age, sex, and Charlson comorbidity index, deep neural network analysis of the posterior tibial artery waveform provided independent prediction of death (hazard ratio [HR], 2.44 [95% CI, 1.78-3.34]), major adverse cardiac events (HR, 1.97 [95% CI, 1.49-2.61]), and major adverse limb events (HR, 11.03 [95% CI, 5.43-22.39]) at 5 years.

CONCLUSIONS

An artificial intelligence-enabled analysis of Doppler arterial waveforms enables identification of major adverse outcomes among patients with peripheral artery disease, which may promote early adoption and adherence of risk factor modification.

Self-pay insurance status is associated with failure of medical therapy in patients with acute uncomplicated type B aortic dissection

BACKGROUND

Traditionally, acute uncomplicated type B aortic dissections are managed medically, and acute complicated dissections are managed surgically. Self-pay patients with medically managed acute uncomplicated type B aortic dissections may fare worse than their insured counterparts.

METHODS

In this single-center, retrospective cohort study, demographics, follow-up, and outcomes of patients with acute type B aortic dissections from 2011 to 2020 were analyzed.

RESULTS

In total, 159 patients presented with acute type B aortic dissections; 102 were complicated and managed with thoracic endovascular aortic repair, and 57 were uncomplicated and managed medically. A total of 32% (n = 51) were self-pay. Self-pay patients were from areas with worse area deprivation indices (71% vs 63%, P = .024). They more often reported alcohol abuse (28% vs 7%, P < .001), cocaine/methamphetamine use (16% vs 5%, P = .028), and nonadherence to home antihypertensives (35% vs 11%, P < .001). Self-pay patients less often had a primary care physician (65% vs 7%, P < .001) or took antihypertensives before admission (31% vs 58%, P = .003). Self-pay patients frequently required financial assistance at discharge (63%), most often using charity funds (46%). Few patients (7%) qualified for our hospital's financial assistance program, and most (78%) remained uninsured at the first follow-up. Self-pay acute uncomplicated type B aortic dissections patients had the lowest rate of follow-up (31% vs 66%, P < .001) and were more likely to represent emergently (75% vs 0%, P = .033) compared to insured acute uncomplicated type B aortic dissections patients. Self-pay patients were more likely to follow up after thoracic endovascular aortic repair for acute complicated type B aortic dissections (82% vs 31%, P < .001).

CONCLUSION

Self-pay patients have multiple, interconnected, complex socioeconomic factors that likely influence preadmission risk for dissection and post-discharge adherence to optimal medical management. Further research is needed to clarify treatment strategies in this high-risk group.

Dual-eligible, dual-risk? A brief review on the impact of dual-eligible status on health disparities and peripheral artery disease

Peripheral artery disease (PAD) has been associated with poorer outcomes based on particular social determinants of health, including insurance status. A unique population to study treatment outcomes related to PAD is those with dual-eligible status-those who qualify for both Medicare and Medicaid-comprising more than 12 million people. We performed a systematic review of the literature surrounding dual-eligible patients and impact on PAD, with final inclusion of six articles. Dual eligibility has been associated with higher rates of comorbidities; more severe symptoms at initial presentation for PAD; and poorer treatment outcomes, including mortality. Further studies are needed to specifically look at the association between PAD and dual-eligible status, but what is clear is that patients in this population would benefit from early identification to prevent disease progression and improve equity.

Application of decellularized vascular matrix in small-diameter vascular grafts

Coronary artery bypass grafting (CABG) remains the most common procedure used in cardiovascular surgery for the treatment of severe coronary atherosclerotic heart disease. In coronary artery bypass grafting, small-diameter vascular grafts can potentially replace the vessels of the patient. The complete retention of the extracellular matrix, superior biocompatibility, and non-immunogenicity of the decellularized vascular matrix are unique advantages of small-diameter tissue-engineered vascular grafts. However, after vascular implantation, the decellularized vascular matrix is also subject to thrombosis and neoplastic endothelial hyperplasia, the two major problems that hinder its clinical application. The keys to improving the long-term patency of the decellularized matrix as vascular grafts include facilitating early endothelialization and avoiding intravascular thrombosis. This review article sequentially introduces six aspects of the decellularized vascular matrix as follows: design criteria of vascular grafts, components of the decellularized vascular matrix, the changing sources of the decellularized vascular matrix, the advantages and shortcomings of decellularization technologies, modification methods and the commercialization progress as well as the application prospects in small-diameter vascular grafts.

Impact of risk factor control on peripheral artery disease outcomes and health disparities

BACKGROUND

Peripheral artery disease (PAD) is associated with modifiable atherosclerotic risk factors like hypertension, diabetes, hyperlipidemia, and smoking. However, the effect of risk factor control on outcomes and disparities in achieving control is less well understood.

METHODS

All patients in an integrated, regional health system with PAD-related encounters, fee-for-service Medicare, and clinical risk factor control data were identified. Component risk factors were dichotomized into controlled and uncontrolled categories (control defined as low-density lipoprotein < 100 mg/dL, hemoglobin A1c < 7.0%, SBP < 140 mmHg, and current nonsmoker) and composite categories (none, 1, ⩾ 2 uncontrolled RFs) created. The primary outcome was major adverse vascular events (MAVE, a composite of all-cause mortality, myocardial infarction, stroke, and lower-extremity revascularization and amputation).

RESULTS

The cohort included 781 patients with PAD, average age 72.5 ± 9.8 years, of whom 30.1% were Black, and 19.1% were Medicaid dual-enrolled. In this cohort, 260 (33.3%) had no uncontrolled risk factors and 200 (25.6%) had two or more uncontrolled risk factors. Patients with the poorest risk factor control were more likely to be Black (p < 0.001), Medicaid dual-enrolled (p < 0.001), and have chronic limb-threatening ischemia (p = 0.009). Significant differences in MAVE by degree of risk factor control were observed at 30 days (none uncontrolled: 5.8%, 1 uncontrolled: 11.5%, ⩾ 2 uncontrolled: 13.6%; p = 0.01) but not at 1 year (p = 0.08). risk factor control was not associated with outcomes at 1 year after adjustment for patient and PAD-specific characteristics.

CONCLUSIONS

risk factor control is poor among patients with PAD. Significant disparities in achieving optimal risk factor control represent a potential target for reducing inequities in outcomes.

Rates of Diabetes-Related Major Amputations Among Racial and Ethnic Minority Adults Following Medicaid Expansion Under the Patient Protection and Affordable Care Act

Importance

It is not known whether implementation of Medicaid expansion under the Patient Protection and Affordable Care Act (ACA) was associated with improvements in the outcomes among racial and ethnic minority adults at risk of diabetes-related major amputations.

Objective

To explore the association of early Medicaid expansion with outcomes of diabetic foot ulcerations (DFUs).

Design, Setting, and Participants

This cohort study included hospitalizations for DFUs among African American, Asian and Pacific Islander, American Indian or Alaska Native, and Hispanic adults as well as adults with another minority racial or ethnic identification aged 20 to 64 years. Data were collected from the State Inpatient Databases for 19 states and the District of Columbia for 2013 to the third quarter of 2015. The analysis was performed on December 4, 2019, and updated on November 9, 2021.

Exposures

States were categorized into early-adopter states (expansion by January 2014) and nonadopter states.

Main Outcomes and Measures

Poisson regression was performed to examine the associations of state type, time, and their combined association with the proportional changes of major amputation rate per year per 100 000 population.

Results

Among the 115 071 hospitalizations among racial and ethnic minority adults with DFUs (64% of sample aged 50 to 64 years; 35%, female; 61%, African American; 25%, Hispanic; 14%, other racial and ethnic minority group), there were 36 829 hospitalizations (32%) for Medicaid beneficiaries and 10 500 hospitalizations (9%) for uninsured patients. Hospitalizations increased 3% (95% CI, 1% to 5%) in early-adopter states and increased 8% (95% CI, 6% to 10%) in nonadopter states after expansion, a significant difference (P for interaction < .001). Although there was no change in the amputation rate (0.08%; 95% CI, -6% to 7%) in early-adopter states after expansion, there was a 9% (95% CI, 3% to 16%) increase in nonadopter states, a significant change (P = .04). For uninsured adults, the amputation rate decreased 33% (95% CI, 10% to 50%) in early-adopter states and did not change (12%; 95% CI, -10% to 38%) in nonadopter states after expansion, a significant difference (P = .006). There was no difference in the change of amputation rate among Medicaid beneficiaries between state types after expansion.

Conclusions and Relevance

This study found a relative improvement in the major amputation rate among African American, Hispanic, and other racial and ethnic minority adults in early-expansion states compared with nonexpansion states, which could be because of the recruitment of at-risk uninsured adults into the Medicaid program during the first 2 years of ACA implementation. Future study is required to evaluate the long-term association of Medicaid expansion and the rates of amputation.

Bioengineering artificial blood vessels from natural materials

Bioengineering an effective, small diameter (<6 mm) artificial vascular graft for use in bypass surgery when autologous grafts are unavailable remains a persistent challenge. Commercially available grafts are typically made from plastics, which have high strength but lack elasticity and present a foreign surface that triggers undesirable biological responses. Tissue engineered grafts, leveraging decellularized animal vessels or derived de novo from long-term cell culture, have dominated recent research, but failed to meet clinical expectations. More effective constructs that are readily translatable are urgently needed. Recent advances in natural materials have made the production of robust acellular conduits feasible and their use increasingly attractive. Here, we identify a subset of natural materials with potential to generate durable, small diameter vascular grafts.

Resorbable vascular grafts show rapid cellularization and degradation in the ovine carotid

Small-diameter vascular grafts perform poorly as arterial bypasses. We developed a cell-free, resorbable graft intended to remodel in situ into a living vessel. The graft consisted of a soft electrospun poly(glycerol sebacate) (PGS) core, a PGS prepolymer (pPGS) coating, and a reinforcing electrospun poly(ε-caprolactone) (PCL) sheath. The core contained 4.37 ± 1.95 μm fibers and had a porosity of 66.4 ± 3.2%, giving it large pores to encourage cellular infiltration and pro-healing macrophages. The sheath contained 6.63 ± 0.89 μm fibers and had a porosity of 80.5 ± 2.1%. in vitro testing suggested that the stress achieved at arterial pressure would be 13-fold lower than the yield stress of the graft. Grafts were implanted as 7 cm carotid interpositions in two sheep. Sheep were maintained on dual antiplatelet therapy and followed with duplex ultrasound. One graft ruptured at 13 days. The second animal was euthanized with a dilated graft at 15 days. Histology showed near-total degradation of the core and a robust inflammatory response within the sheath. Little neotissue had formed within the graft wall or lumen, but the graft had become surrounded by fibroblast-rich and vascularized connective tissue. Because PCL is commonly used in resorbable grafts, this mechanical destabilization was unexpected. We speculate that the inflammatory response instigated by the rapidly degrading PGS intensified degradation of the PCL and that the large pores enabled a prolonged acute host-graft reaction which attacked the entire bulk of the material, speeding weakening. Future work will focus on how to moderate inflammation and improve remodeling of grafts in large animals.

Treatment of Acute Cholecystitis: Do Medicaid and Non-Medicaid Enrolled Patients Receive the Same Care?

BACKGROUND

Nationally, Medicaid enrollees with emergency surgical conditions experience worse outcomes overall when compared with privately insured patients. The goal of this study is to investigate disparities in the treatment of cholecystitis based on insurance type and to identify contributing factors.

METHODS

Adults with cholecystitis at a safety-net hospital in Central Massachusetts from 2017-2018 were included. Sociodemographic and clinical characteristics were compared based on Medicaid enrollment status (Medicare excluded). Univariate and multivariate analyses were used to compare the frequency of surgery, time to surgery (TTS), length of stay (LOS), and readmission rates between groups.

RESULTS

The sample (n = 203) included 69 Medicaid enrollees (34%), with a mean age of 44.4 years. Medicaid enrollees were younger (p = 0.0006), had lower levels of formal education (high school diploma attainment, p < 0.0001), were more likely to be unmarried (p < 0.0001), Non-White (p = 0.0012), and require an interpreter (p < 0.0001). Patients in both groups experienced similar rates of laparoscopic cholecystectomy, TTS, and LOS; however, Medicaid enrollees experienced more readmissions within 30 days of discharge (30.4% vs 17.9%, p < 0.001).

CONCLUSION

Despite anticipated population differences, the treatment of acute cholecystitis was similar between Medicaid and Non-Medicaid enrollees, with the exception of readmission. Further research is needed to identify patient, provider, and/or population factors driving this disparity.

Quickening: Translational design of resorbable synthetic vascular grafts

Traditional tissue-engineered vascular grafts have yet to gain wide clinical use. The difficulty of scaling production of these cell- or biologic-based products has hindered commercialization. In situ tissue engineering bypasses such logistical challenges by using acellular resorbable scaffolds. Upon implant, the scaffolds become remodeled by host cells. This review describes the scientific and translational advantages of acellular, synthetic vascular grafts. It surveys in vivo results obtained with acellular synthetics over their fifty years of technological development. Finally, it discusses emerging principles, highlights strategic considerations for designers, and identifies questions needing additional research.

Innovative Informatics Approaches for Peripheral Artery Disease: Current State and Provider Survey of Strategies for Improving Guideline-Based Care

OBJECTIVE

To quantify compliance with guideline recommendations for secondary prevention in peripheral artery disease (PAD) using natural language processing (NLP) tools deployed to an electronic health record (EHR) and investigate provider opinions regarding clinical decision support (CDS) to promote improved implementation of these strategies.

PATIENTS AND METHODS

Natural language processing was used for automated identification of moderate to severe PAD cases from narrative clinical notes of an EHR of patients seen in consultation from May 13, 2015, to July 27, 2015. Guideline-recommended strategies assessed within 6 months of PAD diagnosis included therapy with statins, antiplatelet agents, angiotensin-converting enzyme inhibitors or angiotensin receptor blockers, and smoking abstention. Subsequently, a provider survey was used to assess provider knowledge regarding PAD clinical practice guidelines, comfort in recommending secondary prevention strategies, and potential role for CDS.

RESULTS

Among 73 moderate to severe PAD cases identified by NLP, only 12 (16%) were on 4 guideline-recommended strategies. A total of 207 of 760 (27%) providers responded to the survey; of these 141 (68%) were generalists and 66 (32%) were specialists. Although 183 providers (88%) managed patients with PAD, 51 (25%) indicated they were uncomfortable doing so; 138 providers (67%) favored the development of a CDS system tailored for their practice and 146 (71%) agreed that an automated EHR-derived mortality risk score calculator for patients with PAD would be helpful.

CONCLUSION

Natural language processing tools can identify cases from EHRs to support quality metric studies. Findings of this pilot study demonstrate gaps in application of guideline-recommended strategies for secondary risk prevention for patients with moderate to severe PAD. Providers strongly support the development of CDS systems tailored to assist them in providing evidence-based care to patients with PAD at the point of care.

Race and Socioeconomic Status Independently Affect Risk of Major Amputation in Peripheral Artery Disease

Background

Black race has been shown to be a risk factor for amputation in peripheral artery disease (PAD); however, race has been argued to be a marker for socioeconomic status (SES) rather than true disparity. The aim of this study is to study the impact of race and SES on amputation risk in PAD patients.

Methods and Results

Patients with incident PAD in the national Veterans Affairs Corporate Data Warehouse were identified from 2003 to 2014 (N=155 647). The exposures were race and SES (measured by median income in residential ZIP codes). The outcome was incident major amputation. Black veterans were significantly more likely to live in low‐SES neighborhoods and to present with advanced PAD. Black patients had a higher amputation risk in each SES stratum compared with white patients. In Cox models (adjusting for covariates), black race was associated with a 37% higher amputation risk compared with white race (hazard ratio: 1.37; 95% confidence interval, 1.30–1.45), whereas low SES was independently predictive of increased risk of amputation (hazard ratio: 1.12; 95% confidence interval, 1.06–1.17) and showed no evidence of interaction with race. In predicted amputation risk analysis, black race and low SES continued to be significant risk factors for amputation regardless of PAD presentation.

Conclusions

Black race significantly increases the risk of amputation within the same SES stratum compared with white race and has an independent effect on limb loss after controlling for comorbidities, severity of PAD at presentation, and use of medications.

Population-based assessment of racial/ethnic differences in utilization of radical cystectomy for patients diagnosed with bladder cancer

PURPOSE

Radical cystectomy is a surgical treatment for recurrent non-muscle-invasive and muscle-invasive bladder cancer; however, many patients may not receive this treatment.

METHODS

A total of 27,578 patients diagnosed with clinical stage I-IV bladder cancer from 1 January 2007 to 31 December 2013 were identified from the Surveillance, Epidemiology, and End Results (SEER) registry database. We used multivariable regression analyses to identify factors predicting the use of radical cystectomy and pelvic lymph node dissection. Cox proportional hazards models were used to analyze survival outcomes.

RESULTS

A total of 1,693 (6.1%) patients with bladder cancer underwent radical cystectomy. Most patients (92.4%) who underwent radical cystectomy also underwent pelvic lymph node dissection. When compared with white patients, non-Hispanic blacks were less likely to undergo a radical cystectomy [odds ratio (OR) 0.79, 95% confidence interval (CI) 0.64-0.96, p = 0.019]. Moreover, recent year of surgery 2013 versus 2007 (OR 2.32, 95% CI 1.90-2.83, p < 0.001), greater percentage of college education ≥36.3 versus <21.3% (OR 1.23, 95% CI 1.04-1.44, p = 0.013), Midwest versus West (OR 1.64, 95% CI 1.39-1.94, p < 0.001), and more advanced clinical stage III versus I (OR 29.1, 95% CI 23.9-35.3, p < 0.001) were associated with increased use of radical cystectomy. Overall survival was improved for patients who underwent radical cystectomy compared with those who did not undergo a radical cystectomy (hazard ratio 0.88, 95% CI 0.80-0.97, p = 0.008).

CONCLUSION

There is significant underutilization of radical cystectomy in patients across all age groups diagnosed with bladder cancer, especially among older, non-Hispanic black patients.

Manufacture of patient-specific vascular replicas for endovascular simulation using fast, low-cost method

Patient-specific vascular replicas are essential to the simulation of endovascular treatment or for vascular research. The inside of silicone replica is required to be smooth for manipulating interventional devices without resistance. In this report, we demonstrate the fabrication of patient-specific silicone vessels with a low-cost desktop 3D printer. We show that the surface of an acrylonitrile butadiene styrene (ABS) model printed by the 3D printer can be smoothed by a single dipping in ABS solvent in a time-dependent manner, where a short dip has less effect on the shape of the model. The vascular mold is coated with transparent silicone and then the ABS mold is dissolved after the silicone is cured. Interventional devices can pass through the inside of the smoothed silicone vessel with lower pushing force compared to the vessel without smoothing. The material cost and time required to fabricate the silicone vessel is about USD $2 and 24 h, which is much lower than the current fabrication methods. This fast and low-cost method offers the possibility of testing strategies before attempting particularly difficult cases, while improving the training of endovascular therapy, enabling the trialing of new devices, and broadening the scope of vascular research.