Enhancing walking performance in patients with peripheral arterial disease: An intervention with ankle-foot orthosis.

Lower extremity peripheral artery disease (PAD) is a cardiovascular condition manifesting from narrowed or blocked arteries supplying the legs. Gait is impaired in patients with PAD. Recent evidence suggests that walking with carbon fiber ankle foot orthoses (AFOs) can improve patient mobility and delay claudication time. This study aimed to employ advanced biomechanical gait analysis to evaluate the impact of AFO intervention on gait performance among patients with PAD. Patients with claudication had hip, knee, and ankle joint kinetics and kinematics assessed using a cross-over intervention design. Participants walked over the force platforms with and without AFOs while kinematic data was recorded with motion analysis cameras. Kinetics and kinematics were combined to quantify torques and powers during the stance period of the gait cycle. The AFOs effectively reduced the excessive ankle plantar flexion and knee extension angles, bringing the patients' joint motions closer to those observed in healthy individuals. After 3 months of the AFO intervention, the hip range of motion decreased, likely due to changes occurring within the ankle chain. With the assistance of the AFOs, the biological power generation required from the ankle and hip during the push-off phase of walking decreased. Wearing AFOs resulted in increased knee flexor torque during the loading response phase of the gait. Based on this study, AFOs may allow patients with PAD to maintain or improve gait performance. More investigation is needed to fully understand and improve the potential benefits of ankle assistive devices.

Lower limb revascularization leads to faster walking but with less efficient mechanics in claudicating patients.

Peripheral artery disease (PAD) is characterized by reduced blood flow to the extremities due to atherosclerosis. Studies report impaired gait mechanics in patients with lower extremity PAD. We hypothesized that revascularization surgery would improve gait mechanics when quantified by net lower limb joint work across the stance phase of walking. We performed gait analyses in 35 patients with PAD and 35 healthy, older adults. Patients with PAD performed a walking protocol prior to and six months following revascularization surgery. Healthy adults only took part in a single walking session. Lower limb joint powers were calculated using inverse dynamics and were integrated across early, middle, and late stance phases to determine the work performed during each phase (J kg-1). The work mechanical ratio between positive-producing and negative-producing phases of stance was calculated for each lower-limb joint. Self-selected walking speed significantly increased from 1.13 ± 0.2 ms-1 to 1.26 ± 0.18 ms-1 in patients following revascularization (p < 0.001). We observed a significant decrease in positive late stance work (p < 0.001) in conjunction with more negative work during early stance (p < 0.001) in patients following revascularization. Revascularization surgery led to faster walking without an increase in the ankle joint's mechanical ratio. Our results suggest faster walking was achieved via work done at the hip rather than the ankle. These findings suggest that additional therapies that facilitate the restoration of muscle, tissue, and nervous system damage caused by years of having reduced blood flow to the limbs might still be beneficial following revascularization.

Peripheral artery disease causes consistent gait irregularities regardless of the location of leg claudication pain.

BACKGROUND: The most common symptom of peripheral artery disease (PAD) is intermittent claudication that involves the calf, thigh, and/or buttock muscles. How the specific location of this leg pain is related to altered gait, however, is unknown. OBJECTIVES: We hypothesized that because the location of claudication symptoms uniquely affects different leg muscle groups in people with PAD, this would produce distinctive walking patterns. METHODS: A total of 105 participants with PAD and 35 age-matched older volunteers without PAD (CTRL) were recruited. Participants completed walking impairment questionnaires (WIQ), Gardner-Skinner progressive treadmill tests, the six-minute walk test, and we performed an advanced evaluation of the biomechanics of their overground walking. Participants with PAD were categorized into 4 groups according to their stated pain location(s): calf only (C, n = 43); thigh and calf (TC, n = 18); buttock and calf (BC, n = 15); or buttock, thigh, and calf (BTC, n = 29). Outcomes were compared between CTRL, C, TC, BC and BTC groups using a one-way ANOVA with post-hoc comparisons to identify and assess statistically significant differences. RESULTS: There were no significant differences between CTRL, C, TC, BC and BTC groups in distances walked or walking speed when either pain-free or experiencing claudication pain. Each participant with PAD had significantly dysfunctional biomechanical gait parameters, even when pain-free, when compared to CTRL (pain-free) walking data. During pain-free walking, out of the 18 gait parameters evaluated, we only identified significant differences in hip power generation during push-off (in C and TC groups) and in knee power absorption during weight acceptance (in TC and BC groups). There were no between-group differences in gait parameters while people with PAD were walking with claudication pain. CONCLUSIONS: Our data demonstrate that PAD affects the ischemic lower extremities in a diffuse manner irrespective of the location of claudication symptoms. DATABASE REGISTRATION: ClinicalTrials.gov NCT01970332.

A Retrospective Cohort Study to Evaluate Adding Biomarkers to the Risk Analysis Index of Frailty.

INTRODUCTION: The Risk Analysis Index (RAI) is a frailty assessment tool associated with adverse postoperative outcomes including 180 and 365-d mortality. However, the RAI has been criticized for only containing subjective inputs rather than including more objective components such as biomarkers. METHODS: We conducted a retrospective cohort study to assess the benefit of adding common biomarkers to the RAI using the Veterans Affairs Surgical Quality Improvement Program (VASQIP) database. RAI plus body mass index (BMI), creatinine, hematocrit, and albumin were evaluated as individual and composite variables on 180-d postoperative mortality. RESULTS: Among 480,731 noncardiac cases in VASQIP from 2010 to 2014, 324,320 (67%) met our inclusion criteria. Frail patients (RAI ≥30) made up to 13.0% of the sample. RAI demonstrated strong discrimination for 180-d mortality (c = 0.839 [0.836-0.843]). Discrimination significantly improved with the addition of Hematocrit (c = 0.862 [0.859-0.865]) and albumin (c = 0.870 [0.866-0.873]), but not for body mass index (BMI) or creatinine. However, calibration plots demonstrate that the improvement was primarily at high RAI values where the model overpredicts observed mortality. CONCLUSIONS: While RAI's ability to predict the risk of 180-d postoperative mortality improves with the addition of certain biomarkers, this only observed in patients classified as very frail (RAI >49). Because very frail patients have significantly elevated observed and predicted mortality, the improved discrimination is likely of limited clinical utility for a frailty screening tool.

A comparison of the perceptions of wearing an ankle foot orthosis by individuals with peripheral artery disease according to their baseline-level of physical activity.

INTRODUCTION: Peripheral artery disease (PAD) is a prevalent cardiovascular disease that limits an individual's ability to walk. One potential way to improve physical activity for patients with PAD is an ankle foot orthosis (AFO). Previous research has found that various factors may influence an individual's willingness to wear AFOs. However, one factor that has been understudied is an individual's baseline physical activity level prior to wearing AFOs. Therefore, the purpose of this study was to compare the perceptions of wearing AFOs for 3 months among individuals with PAD according to their baseline level of physical activity. METHODS: Accelerometer-derived physical activity prior to AFO prescription was used to classify participants into either a higher or lower activity group. Semi-structured interviews were conducted at 1.5 and 3-months after wearing the AFOs to assess participants' perceptions of using the orthosis. Data were analyzed by a directed content analysis approach, then the percentage of respondents for each theme were calculated and compared between higher and lower activity groups. FINDINGS: Several differences were found. Participants in the higher activity group more often reported positive impacts from wearing the AFOs. Additionally, participants who were in the lower activity group more often reported the AFOs caused physical pain while participants in the higher activity group more often reported the device was uncomfortable during daily activities. CONCLUSION: Baseline physical activity levels may help to better understand barriers to wear and needed support to increase adherence to an AFO wear prescription, especially for patients with PAD with limited activity.

Association of Routine Preoperative Frailty Assessment With 1-Year Postoperative Mortality.

Importance: Patient frailty is a known risk factor for adverse outcomes following surgery, but data are limited regarding whether systemwide interventions related to frailty are associated with improved patient outcomes. Objective: To evaluate whether a frailty screening initiative (FSI) is associated with reduced late-term mortality after elective surgery. Design, Setting, and Participants: This quality improvement study with an interrupted time series analysis used data from a longitudinal cohort of patients in a multihospital, integrated health care system in the US. Beginning in July 2016, surgeons were incentivized to measure frailty with the Risk Analysis Index (RAI) for all patients considering elective surgery. Implementation of the BPA occurred in February 2018. The cutoff for data collection was May 31, 2019. Analyses were conducted between January and September 2022. Exposures: The exposure of interest was an Epic Best Practice Alert (BPA) used to identify patients with frailty (RAI ≥42) and prompt surgeons to document a frailty-informed shared decision-making process and consider additional evaluation by a multidisciplinary presurgical care clinic or the primary care physician. Main Outcomes and Measures: The primary outcome was 365-day mortality after the elective surgical procedure. Secondary outcomes included 30-day and 180-day mortality as well as the proportion of patients referred for additional evaluation based on documented frailty. Results: A total of 50 463 patients with at least 1 year of postsurgical follow-up (22 722 before intervention implementation and 27 741 after) were included (mean [SD] age, 56.7 [16.0] y; 57.6% women). Demographic characteristics, RAI score, and operative case mix, as defined by Operative Stress Score, were similar between time periods. After BPA implementation, the proportion of frail patients referred to a primary care physician and presurgical care clinic increased significantly (9.8% vs 24.6% and 1.3% vs 11.4%, respectively; both P < .001). Multivariable regression analysis demonstrated an 18% reduction in the odds of 1-year mortality (0.82; 95% CI, 0.72-0.92; P < .001). Interrupted time series models demonstrated a significant slope change in the rate of 365-day mortality from 0.12% in the preintervention period to -0.04% in the postintervention period. Among patients triggering the BPA, estimated 1-year mortality changed by -4.2% (95% CI, -6.0% to -2.4%). Conclusions and Relevance: This quality improvement study found that implementation of an RAI-based FSI was associated with increased referrals of frail patients for enhanced presurgical evaluation. These referrals translated to a survival advantage among frail patients of similar magnitude to those observed in a Veterans Affairs health care setting, providing further evidence for both the effectiveness and generalizability of FSIs incorporating the RAI.

A biomechanical perspective on walking in patients with peripheral artery disease.

The most common symptom of peripheral artery disease (PAD) is intermittent claudication, which consists of debilitating leg pain during walking. In clinical settings, the presence of PAD is often noninvasively evaluated using the ankle-brachial index and imaging of the arterial supply. Furthermore, various questionnaires and functional tests are commonly used to measure the severity and negative effect of PAD on quality of life. However, these evaluations only provide information on vascular insufficiency and severity of the disease, but not regarding the complex mechanisms underlying walking impairments in patients with PAD. Biomechanical analyses using motion capture and ground reaction force measurements can provide insight into the underlying mechanisms to walking impairments in PAD. This review analyzes the application of biomechanics tools to identify gait impairments and their clinical implications on rehabilitation of patients with PAD. A total of 18 published journal articles focused on gait biomechanics in patients with PAD were studied. This narriative review shows that the gait of patients with PAD is impaired from the first steps that a patient takes and deteriorates further after the onset of claudication leg pain. These results point toward impaired muscle function across the ankle, knee, and hip joints during walking. Gait analysis helps understand the mechanisms operating in PAD and could also facilitate earlier diagnosis, better treatment, and slower progression of PAD.

Long-term use of an ankle-foot orthosis intervention in patients with peripheral artery disease using the integrated promoting action on research implementation in health services (i-PARIHS) framework.

BACKGROUND: Peripheral artery disease (PAD) is a cardiovascular disease that limits patients' walking ability. Persistent ankle-foot orthosis (AFO) use may increase the distance patients can walk as well as physical activity. PURPOSE: The purpose of the study was to determine the implementation and patients' perspectives related to the use or disuse of the AFO intervention six months post-intervention. This study was guided by a semi-structured interview and survey based on the integrated Promoting Action on Research Implementation in Health Services (i-PARIHS) constructs. DESIGN: A convergent mixed methods design was used to evaluate participants' perceptions six months following a three-month AFO intervention. A survey and semi-structured questionnaire based on the i-PARIHS constructs were administered and analyzed. SETTING: Vascular surgery clinic and biomechanics research laboratory. PARTICIPANTS: Patients (N = 7; male, 100%; age, 71.9 ± 0.6.7y; body mass index, 29.0 ± 0.5.5; ankle brachial index 0.50 ± 0.17) with claudication completed the study. INTERVENTIONS: A certified orthotist fit participants with an AFO that was worn for 3 months. MAIN OUTCOME MEASURES: Qualitative analysis of semi-structured interviews and quantitative analysis of the survey. RESULTS: The highest positive ratings were seen in the dimensions of usability and cost-effectiveness. The patients found the AFO device and instructions to wear, easy when starting the intervention and there were no out-of-pocket costs. The lower scores and challenges faced with observability and relative advantage domains indicated issues related to motivation for sustained use of the AFO. CONCLUSIONS: Barriers associated with AFO function that prevent common activities and poor health seem to be the biggest issue for not wanting to wear the AFO after the 3-month intervention. Addressing patients' perceptions and challenges to wearing the AFO is essential to increasing compliance and physical activity. Future research should concentrate on understanding the compatibility of orthotic device interventions with the subject's lifestyle. CLINICAL TRIAL REGISTRATION NO: NCT02902211.

Assessing wear time and perceptions of wearing an ankle foot orthosis in patients with peripheral artery disease.

BACKGROUND: Peripheral artery disease (PAD) is a cardiovascular disease that affects walking ability. An ankle foot orthosis (AFO) may improve walking distances in those with PAD. Little research has explored if those with PAD wear a prescribed AFO and their perceptions of wearing the device. OBJECTIVE: To assess wear time of an AFO and explore perceptions of wearing the device in patients with PAD. DESIGN: Convergent mixed methods. SETTING: The study was conducted through a tertiary care medical center, and the research participants used the device in the community. PARTICIPANTS: Thirty-six patients, all older adult males, were enrolled in this study. Fourteen patients completed the study and 11 supplied sufficient accelerometer data to include in the analysis. INTERVENTIONS: An AFO was worn for 3 months. An accelerometer was placed on the AFO for 7 days at the midpoint (1.5 months) and endpoint of the intervention (3 months) to assess wear time. Semi-structured interviews explored patients' perceptions of wearing the AFO. MAIN OUTCOME MEASURE: The primary outcome measure was wear time measured objectively via accelerometer and subjectively via interview. RESULTS: Patients (n = 14) wore the AFO approximately 8 hours/day. Patients reported barriers such as challenges wearing the AFO during daily household activities (using stairs, being on uneven terrain), discomfort, clothing or footwear issues, and driving challenges. Positive effects of wearing the AFO were also reported, primarily the ability to walk further. CONCLUSIONS: An AFO may be an acceptable therapeutic intervention to improve perceived walking performance in older adult males with PAD. Addressing participants' perceptions of the AFO and barriers to wear are essential to increasing the positive effect the device has on participants' ambulatory activity.

Effect of a Decision Aid on Agreement Between Patient Preferences and Repair Type for Abdominal Aortic Aneurysm: A Randomized Clinical Trial.

Importance: Patients with abdominal aortic aneurysm (AAA) can choose open repair or endovascular repair (EVAR). While EVAR is less invasive, it requires lifelong surveillance and more frequent aneurysm-related reinterventions than open repair. A decision aid may help patients receive their preferred type of AAA repair. Objective: To determine the effect of a decision aid on agreement between patient preference for AAA repair type and the repair type they receive. Design, Setting, and Participants: In this cluster randomized trial, 235 patients were randomized at 22 VA vascular surgery clinics. All patients had AAAs greater than 5.0 cm in diameter and were candidates for both open repair and EVAR. Data were collected from August 2017 to December 2020, and data were analyzed from December 2020 to June 2021. Interventions: Presurgical consultation using a decision aid vs usual care. Main Outcomes and Measures: The primary outcome was the proportion of patients who had agreement between their preference and their repair type, measured using χ2 analyses, κ statistics, and adjusted odds ratios. Results: Of 235 included patients, 234 (99.6%) were male, and the mean (SD) age was 73 (5.9) years. A total of 126 patients were enrolled in the decision aid group, and 109 were enrolled in the control group. Within 2 years after enrollment, 192 (81.7%) underwent repair. Patients were similar between the decision aid and control groups by age, sex, aneurysm size, iliac artery involvement, and Charlson Comorbidity Index score. Patients preferred EVAR over open repair in both groups (96 of 122 [79%] in the decision aid group; 81 of 106 [76%] in the control group; P = .60). Patients in the decision aid group were more likely to receive their preferred repair type than patients in the control group (95% agreement [93 of 98] vs 86% agreement [81 of 94]; P = .03), and κ statistics were higher in the decision aid group (κ = 0.78; 95% CI, 0.60-0.95) compared with the control group (κ = 0.53; 95% CI, 0.32-0.74). Adjusted models confirmed this association (odds ratio of agreement in the decision aid group relative to control group, 2.93; 95% CI, 1.10-7.70). Conclusions and Relevance: Patients exposed to a decision aid were more likely to receive their preferred AAA repair type, suggesting that decision aids can help better align patient preferences and treatments in major cardiovascular procedures. Trial Registration: ClinicalTrials.gov Identifier: NCT03115346.

Peripheral artery disease affects the function of the legs of claudicating patients in a diffuse manner irrespective of the segment of the arterial tree primarily involved.

Different levels of arterial occlusive disease (aortoiliac, femoropopliteal, multi-level disease) can produce claudication symptoms in different leg muscle groups (buttocks, thighs, calves) in patients with peripheral artery disease (PAD). We tested the hypothesis that different locations of occlusive disease uniquely affect the muscles of PAD legs and produce distinctive patterns in the way claudicating patients walk. Ninety-seven PAD patients and 35 healthy controls were recruited. PAD patients were categorized to aortoiliac, femoropopliteal and multi-level disease groups using computerized tomographic angiography. Subjects performed walking trials both pain-free and during claudication pain and joint kinematics, kinetics, and spatiotemporal parameters were calculated to evaluate the net contribution of the calf, thigh and buttock muscles. PAD patients with occlusive disease affecting different segments of the arterial tree (aortoiliac, femoropopliteal, multi-level disease) presented with symptoms affecting different muscle groups of the lower extremity (calves, thighs and buttocks alone or in combination). However, no significant biomechanical differences were found between PAD groups during the pain-free conditions with minimal differences between PAD groups in the claudicating state. All statistical differences in the pain-free condition occurred between healthy controls and one or more PAD groups. A discriminant analysis function was able to adequately predict if a subject was a control with over 70% accuracy, but the function was unable to differentiate between PAD groups. In-depth gait analyses of claudicating PAD patients indicate that different locations of arterial disease produce claudication symptoms that affect different muscle groups across the lower extremity but impact the function of the leg muscles in a diffuse manner generating similar walking impairments.

Factors associated with preference of choice of aortic aneurysm repair in the PReference for Open Versus Endovascular repair of AAA (PROVE-AAA) study.

OBJECTIVE: Patients can choose between open repair and endovascular repair (EVAR) of abdominal aortic aneurysm (AAA). However, the factors associated with patient preference for one repair type over another are not well-characterized. Here we assess the factors associated with preference of choice for open or endovascular AAA repair among veterans exposed to a decision aid to help with choosing surgical treatment. METHODS: Across 12 Veterans Affairs hospitals, veterans received a decision aid covering domains including patient information sources and understanding preference. Veterans were then given a series of surveys at different timepoints examining their preferences for open versus endovascular AAA repair. Questions from the preference survey were used in analyses of patient preference. Results were analyzed using χ2 tests. A logistic regression analysis was performed to assess factors associated with preference for open repair or preference for EVAR. RESULTS: A total of 126 veterans received a decision aid informing them of their treatment choices, after which 121 completed all preference survey questions; five veterans completed only part of the instruments. Overall, veterans who preferred open repair were typically younger (70 years vs 73 years; P = .02), with similar rates of common comorbidities (coronary disease 16% vs 28%; P = .21), and similar aneurysms compared with those who preferred EVAR (6.0 cm vs 5.7 cm; P = .50). Veterans in both preference categories (28% of veterans preferring EVAR, 48% of veterans preferring open repair) reported taking their doctor's advice as the top box response for the single most important factor influencing their decision. When comparing the tradeoff between less invasive surgery and higher risk of long-term complications, more than one-half of veterans preferring EVAR reported invasiveness as more important compared with approximately 1 in 10 of those preferring open repair (53% vs 12%; P < .001). Shorter recovery was an important factor for the EVAR group (74%) and not important in the open repair group (76%) (P = .5). In multivariable analyses, valuing a short hospital stay (odds ratio, 12.4; 95% confidence interval, 1.13-135.70) and valuing a shorter recovery (odds ratio, 15.72; 95% confidence interval, 1.03-240.20) were associated with a greater odds of preference for EVAR, whereas finding these characteristics not important was associated with a greater odds of preference for open repair. CONCLUSIONS: When faced with the decision of open repair versus EVAR, veterans who valued a shorter hospital stay and a shorter recovery were more likely to prefer EVAR, whereas those more concerned about long-term complications preferred an open repair. Veterans typically value the advice of their surgeon over their own beliefs and preferences. These findings need to be considered by surgeons as they guide their patients to a shared decision.

Patient Compliance With Wearing Lower Limb Assistive Devices: A Scoping Review.

OBJECTIVE: The aim of this scoping review was to identify information on compliance with wearing orthoses and other supportive devices, to discuss the barriers to adherence, and to suggest strategies for improvement based on these findings. METHODS: Online databases of PubMed, Web of Science, and the Cochrane Library were searched for articles about patients' compliance with regard to lower limb assistive devices. In addition, a methodological quality control process was conducted. Studies were included if in the English language and related to compliance and adherence to the lower limb assistive device. Exclusion was based on first reading the abstract and then the full manuscript confirming content was not related to orthotic devices and compliance. RESULTS: Twelve studies were included. The data revealed between 6% and 80% of patients were not using a prescribed device. Barriers to the use of the orthotic device included medical, functional, device properties and lack of proper fit. Strategies for improved compliance included better communication between patient and clinician, patient education, and improved comfort and device esthetics. CONCLUSIONS: Individualized orthotic adjustments, rehabilitation, and patient education were promising for increasing adherence. Despite positive aspects of improvements in gait, balance in elderly, and a sense of security produced by using assistive devices, compliance remains less than ideal due to barriers. As compliance in recent studies has not improved, continued work in this area is essential to realize the benefits of technological advances in orthotic and assistive devices.

Muscle forces and power are significantly reduced during walking in patients with peripheral artery disease.

Patients with peripheral artery disease (PAD) have significantly reduced lower extremity muscle strength compared with healthy individuals as measured during isolated, single plane joint motion by isometric and isokinetic strength dynamometers. Alterations to the force contribution of muscles during walking caused by PAD are not well understood. Therefore, this study used simulations with PAD biomechanics data to understand lower extremity muscle functions in patients with PAD during walking and to compare that with healthy older individuals. A total of 12 patients with PAD and 10 age-matched healthy older controls walked across a 10-meter pathway with reflective markers on their lower limbs. Marker coordinates and ground reaction forces were recorded and exported to OpenSim software to perform gait simulations. Walking velocity, joint angles, muscle force, muscle power, and metabolic rate were calculated and compared between patients with PAD and healthy older controls. Our results suggest that patients with PAD walked slower with less hip extension during propulsion. Significant force and power reductions were observed in knee extensors during weight acceptance and in plantar flexors and hip flexors during propulsion in patients with PAD. The estimated metabolic rate of walking during stance was not different between patients with PAD and controls. This study is the first to analyze lower limb muscular responses during walking in patients with PAD using the OpenSim simulation software. The simulation results of this study identified important information about alterations to muscle force and power during walking in those with PAD.

Comparative Effectiveness of Carotid Stenting to Medical Therapy Among Patients With Asymptomatic Carotid Stenosis.

BACKGROUND: No completed trials have compared carotid artery stenting (CAS) to medical therapy (MT). We examined the effectiveness of CAS compared with MT in patients with asymptomatic carotid stenosis. METHODS: We conducted a retrospective cohort study of 219 979 Veterans ≥65 years who received carotid imaging for asymptomatic carotid stenosis between 2005 and 2009 in the US Veterans Health Administration. We constructed a sample of patients who received MT (n=2509) and comparable patients who received CAS (n=551) and followed them for 5 years. Using target trial methodology, we computed weighted Kaplan-Meier curves and estimated the risk of fatal and nonfatal stroke in each group over 5 years of follow-up. We also estimated the cumulative incidence functions for fatal and nonfatal stroke accounting for nonstroke deaths as competing risks. RESULTS: Five hundred fifty-one patients received CAS, and 2509 patients received MT. The observed rate of stroke or death (perioperative complications) within 30 days in the CAS arm was 2.2%. Using the target trial methodology, the 5-year risk of fatal and nonfatal stroke was similar among patients assigned to CAS (6.9%) compared with patients assigned to MT (7.1%; risk difference, -0.1% [95% CI, -2.6% to 2.7%]). In an analysis that incorporated the competing risk of death, the risk difference between the two arms remained nonsignificant (risk difference, -1.5% [95% CI, -3.0% to 0.3%]). CONCLUSIONS: In this sample of older male adults, we found no difference between MT and CAS in the treatment of asymptomatic carotid stenosis. Future studies in other settings are needed to confirm these findings.

Comparing Veterans Affairs and Private Sector Perioperative Outcomes After Noncardiac Surgery.

Importance: Recent legislation facilitates veterans' ability to receive non-Veterans Affairs (VA) surgical care. However, contemporary data comparing the quality and safety of VA and non-VA surgical care are lacking. Objective: To compare perioperative outcomes among veterans treated in VA hospitals with patients treated in private-sector hospitals. Design, Setting, and Participants: This cohort study took place across 8 noncardiac specialties in the Veterans Affairs Surgical Quality Improvement Program (VASQIP) and American College of Surgeons National Surgical Quality Improvement Program (NSQIP) from January 1, 2015, through December 31, 2018. Multivariable log-binomial modeling was used to evaluate the association between VA vs private sector care settings and 30-day mortality. Unmeasured confounding was quantified using the E-value. Patients 18 years and older undergoing a noncardiac procedures were included. Exposures: Surgical care in either a VA or private sector setting. Main Outcomes and Measures: Primary outcome was 30-day postoperative mortality. Secondary outcome was failure to rescue, defined as a postoperative death after a complication. Results: Of 3 910 752 operations (3 174 274 from NSQIP and 736 477 from VASQIP), 1 498 984 (92.1%) participants in NSQIP were male vs 678 382 (47.2%) in VASQIP (mean difference, -0.449 [95% CI, -0.450 to -0.448]; P < .001), and 441 894 (60.0%) participants in VASQIP were frail or very frail vs 676 525 (21.3%) in NSQIP (mean difference, -0.387 [95% CI, -0.388 to -0.386]; P < .001). Overall, rates of 30-day mortality, complications, and failure to rescue were 0.8%, 9.5%, and 4.7%, respectively, in NSQIP (n = 3 174 274 operations) and 1.1%, 17.1%, and 6.7%, respectively in VASQIP (736 477) (differences in proportions, -0.003 [95% CI, -0.003 to -0.002]; -0.076 [95% CI, -0.077 to -0.075]; 0.020 [95% CI, 0.018-0.021], respectively; P < .001). Compared with private sector care, VA surgical care was associated with a lower risk of perioperative death (adjusted relative risk, 0.59 [95% CI, 0.47-0.75]; P < .001). This finding was robust in multiple sensitivity analyses performed, including among patients who were frail and nonfrail, with or without complications, and undergoing low and high physiologic stress procedures. These findings were also consistent when year was included as a covariate and in nonparsimonious modeling for patient-level factors. Compared with private sector care, VA surgical care was also associated with a lower risk of failure to rescue (adjusted relative risk, 0.55 [95% CI, 0.44-0.68]). An unmeasured confounder (present disproportionately in NSQIP data) would require a relative risk of 2.78 [95% CI, 2.04-3.68] to obviate the main finding. Conclusions and Relevance: VA surgical care is associated with lower perioperative mortality and decreased failure to rescue despite veterans having higher-risk characteristics. Given the unique needs and composition of the veteran population, health policy decisions and budgetary appropriations should reflect these important differences.

Claudicating patients with peripheral artery disease have meaningful improvement in walking speed after supervised exercise therapy.

OBJECTIVE: Supervised exercise therapy (SET) is a first-line treatment for patients with peripheral artery disease (PAD). The efficacy of SET is most commonly expressed by significant statistical improvement of parameters that do not clarify how each individual patient will benefit from SET. This study examined the minimal clinically important difference (MCID) in walking speed in claudicating patients with PAD after SET. METHODS: A total of 63 patients with PAD-related claudication (Fontaine stage II PAD) participated in a 6-month SET program. Self-selected walking speed was measured before and after SET. Distribution and anchor-based approaches were used to estimate the MCID for small and substantial improvement. The ability to walk one block and the ability to climb one flight of stairs questions were chosen as anchor questions from the Medical Outcomes Study 36-item Short Form questionnaire. Receiver operating characteristics curve analyses were performed to detect the threshold for MCID in walking speed after treatment. RESULTS: The distribution-based method estimated 0.03 m/s as a small improvement and 0.08 m/s as a substantial improvement after SET. Small and substantial improvements according to the anchor question walking one block were 0.05 m/s and 0.15 m/s, respectively. For the climbing one flight of stairs anchor question, 0.10 m/s was a small improvement. Receiver operating characteristics curve analyses identified an increase of 0.04 m/s and 0.03 m/s for improvement based on walking one block and climbing one flight of stairs, respectively. CONCLUSIONS: We report our findings for the MCID for walking speed among claudicating patients receiving SET. Claudicating patients who increase walking speed of 0.03 m/s or greater are more likely to experience a meaningful improvement in walking impairment than those who do not. The MCID reported in this study can serve as a benchmark for clinicians to develop goals and interpret clinically meaningful progress in the care of claudicating patients with PAD.