Perceived Versus Objective Change in Walking Ability in Peripheral Artery Disease: Results from 3 Randomized Clinical Trials of Exercise Therapy

Socioeconomic factors predict successful supervised exercise therapy completion

OBJECTIVE

Supervised exercise therapy (SET) for patients with intermittent claudication (IC) can lower the risk of progression to chronic limb-threatening ischemia and amputation, while preserving and restoring functional status. Despite supporting evidence, it remains underutilized, and among those who initiate programs, attrition rates are extremely high. We hypothesize that socioeconomic factors may represent significant barriers to SET completion.

METHODS

Patients with IC referred to SET at a multi-hospital, single-institution health care system (2018-2022) from a prospectively maintained database were retrospectively analyzed. Our primary endpoint was SET program completion and graduation, defined as completion of 36 sessions. Our secondary endpoints were vascular intervention within 1 year of referral and change in ankle-brachial index (ABI). Baseline demographics were assessed using standard statistical methods. Predictors of SET graduation were analyzed using multivariable logistic regression generating adjusted odds ratios (aORs) with 95% confidence intervals (CIs). Change in ABI was analyzed using t-test between subgroups. Reasons for attrition were tabulated. Patient Health Questionnaire-9 (PHQ-9), metabolic equivalent level, Vascular QOL, Duke Activity Status, and ABI were analyzed using paired t-tests across the entire cohort.

RESULTS

Fifty-two patients met inclusion criteria: mean age 67.85 ± 10.69 years, 19 females (36.54%), mean baseline ABI of 0.77 ± 0.16. The co-pays for 100% of patients were fully covered by primary and secondary insurance plans. Twenty-one patients (40.38%) completed SET. On multivariable analysis, residence in a ZIP code with median household income <$47,000 (aOR, 0.10; 95% CI, 0.01-0.76; P = .03) and higher body mass index (aOR, 0.81; 95% CI, 0.67-0.99; P = .04) were significant barriers to SET graduation. There were no differences in ABI change or vascular intervention within 1 year between graduates and non-graduates. Non-graduates reported transportation challenges (25.00%), lack of motivation (20.83%), and illness/functional limitation (20.83%) as primary reasons for SET attrition. Metabolic Equivalent Level (P ≤ .01) and Duke Activity Status scores (P = .04) were significantly greater after participating in a SET program.

CONCLUSIONS

Although SET participation improves lower extremity and functionality outcomes, only 40% of referred patients completed therapy in our cohort. Our findings suggest that both socioeconomic and functional factors influence the odds of completing SET programs, indicating a need for holistic pre-referral assessment to facilitate enhanced program accessibility for these populations.

Home-Based Walking Exercise and Supervised Treadmill Exercise in Patients With Peripheral Artery Disease: An Individual Participant Data Meta-Analysis

Importance

Few people with lower extremity peripheral artery disease (PAD) participate in supervised treadmill exercise covered by the Center for Medicare and Medicaid Services. In people with PAD, the benefits of home-based walking exercise, relative to supervised exercise, remain unclear.

Objective

To study whether home-based walking exercise improves 6-minute walk (6MW) more than supervised treadmill exercise in people with PAD (defined as Ankle Brachial Index ≤0.90).

Data Sources

Data were combined from 5 randomized clinical trials of exercise therapy for PAD using individual participant data meta-analyses, published from 2009 to 2022.

Study Selection

Of the 5 clinical trials, 3 clinical trials compared supervised treadmill exercise to nonexercise control (N = 370) and 2 clinical trials compared an effective home-based walking exercise intervention to nonexercise control (N = 349).

Data Extraction and Synthesis

Individual participant-level data from 5 randomized clinical trials led by 1 investigative team were combined. The 5 randomized clinical trials included 3 clinical trials of supervised treadmill exercise and 2 effective home-based walking exercise interventions.

Main Outcomes and Measures

Change in 6MW distance, maximum treadmill walking distance, and Walking Impairment Questionnaire at 6-month follow-up. The supervised treadmill exercise intervention consisted of treadmill exercise in the presence of an exercise physiologist, conducted 3 days weekly for up to 50 minutes per session. Home-based walking exercise consisted of a behavioral intervention in which a coach helped participants walk for exercise in or around home for up to 5 days per week for 50 minutes per session.

Results

A total of 719 participants with PAD (mean [SD] age, 68.8 [9.5] years; 46.5% female) were included (349 in a home-based exercise clinical trial and 370 in a supervised exercise trial). Compared with nonexercise control, supervised treadmill exercise was associated with significantly improved 6MW by 32.9 m (95% CI, 20.6-45.6; P < .001) and home-based walking exercise was associated with significantly improved 6MW by 50.7 m (95% CI, 34.8-66.7; P < .001). Compared with supervised treadmill exercise, home-based walking exercise was associated with significantly greater improvement in 6MW distance (between-group difference: 23.8 m [95% CI, 3.6, 44.0; P = .02]) but significantly less improvement in maximum treadmill walking distance (between-group difference:-132.5 m [95% CI, -192.9 to -72.1; P < .001]).

Conclusions and Relevance

In this individual participant data meta-analyses, compared with supervised exercise, home-based walking exercise was associated with greater improvement in 6MW in people with PAD. These findings support home-based walking exercise as a first-line therapy for walking limitations in PAD.

Discrete Event Simulation Model for Cost-Effectiveness Evaluation of Screening for Asymptomatic Patients with Lower Extremity Arterial Disease

Lower limb ischemic disease (LEAD) affects a significant portion of the population, with most patients being asymptomatic. Patient screening is necessary because LEAD patients have an increased risk of occurrence of other cardiovascular events and manifestations of disease, in terms of leg symptoms such as intermittent claudication, critical limb ischemia, or amputation. The aim of this work was to evaluate the cost-effectiveness of screening using ABI diagnostics in asymptomatic patients and its impact on limb symptoms associated with LEAD. A discrete event simulation model was created to capture lifetime costs and effects. Costs were calculated from the perspective of the health care payer, and the effects were calculated as QALYs. A cost-effectiveness analysis was performed to compare ABI screening examination and the situation without such screening. A probabilistic sensitivity analysis and scenario analysis were carried out to evaluate the robustness of the results. In the basic setting, the screening intervention was a more expensive intervention, at a cost of CZK 174,010, compared to CZK 70,177 for the strategy without screening. The benefits of screening were estimated at 14.73 QALYs, with 14.46 QALYs without screening. The final ICER value of CZK 389,738 per QALY is below the willingness to pay threshold. Likewise, the results of the probabilistic sensitivity analysis and of the scenario analysis were below the threshold of willingness to pay, thus confirming the robustness of the results. In conclusion, ABI screening appears to be a cost-effective strategy for asymptomatic patients aged 50 years when compared to the no-screening option.

Effects of home-based leg heat therapy on walking performance in patients with symptomatic peripheral artery disease: a pilot randomized trial

Few noninvasive therapies currently exist to improve functional capacity in people with lower extremity peripheral artery disease (PAD). The goal of the present study was to test the hypothesis that unsupervised, home-based leg heat therapy (HT) using water-circulating trousers perfused with warm water would improve walking performance in patients with PAD. Patients with symptomatic PAD were randomized into either leg HT (n = 18) or a sham treatment (n = 16). Patients were provided with water-circulating trousers and a portable pump and were asked to apply the therapy daily (7 days/wk, 90 min/session) for 8 wk. The primary study outcome was the change from baseline in 6-min walk distance at 8-wk follow-up. Secondary outcomes included the claudication onset-time, peak walking time, peak pulmonary oxygen consumption and peak blood pressure during a graded treadmill test, resting blood pressure, the ankle-brachial index, postocclusive reactive hyperemia in the calf, cutaneous microvascular reactivity, and perceived quality of life. Of the 34 participants randomized, 29 completed the 8-wk follow-up. The change in 6-min walk distance at the 8-wk follow-up was significantly higher (P = 0.029) in the group exposed to HT than in the sham-treated group (Sham: median: -0.9; 25%, 75% percentiles: -5.8, 14.3; HT: median: 21.3; 25%, 75% percentiles: 10.1, 42.4, P = 0.029). There were no significant differences in secondary outcomes between the HT and sham group at 8-wk follow-up. The results of this pilot study indicate that unsupervised, home-based leg HT is safe, well-tolerated, and elicits a clinically meaningful improvement in walking tolerance in patients with symptomatic PAD.NEW & NOTEWORTHY This is the first sham-controlled trial to examine the effects of home-based leg heat therapy (HT) on walking performance in patients with peripheral artery disease (PAD). We demonstrate that unsupervised HT using water-circulating trousers is safe, well-tolerated, and elicits meaningful changes in walking ability in patients with symptomatic PAD. This home-based treatment option is practical, painless, and may be a feasible adjunctive therapy to counteract the decline in lower extremity physical function in patients with PAD.

Patient-Reported Outcome Measures in Symptomatic, Non-Limb-Threatening Peripheral Artery Disease: A State-of-the-Art Review

Patient-reported outcome measures (PROMs) are health outcomes directly reported by the patient that can be used to measure the effect of disease and treatments on patient perceived well-being. This review summarizes current evidence regarding the validation of PROMs in people with symptomatic, nonlimb-threatening peripheral artery disease. A literature search was conducted to identify studies of symptomatic peripheral artery disease without limb-threatening ischemia that included PROMs and had sample sizes ≥25. PROMs were summarized along a continuum of validation using classical test theory framework and according to whether they fulfilled defined criteria for (1) content validity; (2) psychometric validation; and (3) further validation evidence base expansion. Of 2198 articles identified, 157 (7.1%) met inclusion criteria. Twenty-four PROMs in patients with symptomatic peripheral artery disease were reviewed. Among disease-specific PROMs, 8 of 15 had excellent reliability as measured by a Cronbach alpha ≥0.80. Based on established criteria for PROM responsiveness, 6 of 15 disease-specific PROMs demonstrated excellent sensitivity to change. Of these, the disease-specific peripheral artery questionnaire, vascular quality of life questionnaire, and walking impairment questionnaire met criteria for validation at each stage of the continuum. For generic (nondisease specific) PROMs, the European Quality of Life 5-Dimension and SF-36 had the most extensive evidence of validation. Evidence from this review can inform selection of PROMs aligned with scientific and clinical goals, given the variable degree of validation and potential complementary nature of the measures.

One-Year Change in Walking Performance and Subsequent Mobility Loss and Mortality Rates in Peripheral Artery Disease: Longitudinal Data From the WALCS

Background

Associations of 1‐year change in functional performance measures with subsequent mobility loss and mortality in people with lower extremity peripheral artery disease are unknown.

Methods and Results

Six‐minute walk and 4‐meter walking velocity (usual and fastest pace) were measured at baseline and 1 year later in 612 people with peripheral artery disease (mean age 71±9 years, 37% women). Participants were categorized into tertiles, based on 1‐year changes in walking measures. Cox proportional hazards models were used to examine associations between 1‐year change in each walking measure and subsequent mobility loss and mortality, respectively, adjusting for potential confounders. Compared with the best tertile, the worst tertile (ie, greatest decline) in 1‐year change in each performance measure was associated with higher rates of mobility loss: 6‐minute walk (Tertile 1 [T1] cumulative incidence rate [IR], 72/160; Tertile 3 [T3] IR, 47/160; hazard ratio [HR], 2.35; 95% CI, 1.47–3.74), usual‐paced 4‐meter walking velocity (T1 IR, 54/162; T3 IR, 57/162; HR, 2.21; 95% CI, 1.41–3.47), and fast‐paced 4‐meter walking velocity (T1 IR, 61/162; T3 IR, 58/162; HR, 1.81; 95% CI, 1.16–2.84). Compared with the best tertile, the worst tertiles in 1‐year change in 6‐minute walk (T1 IR, 66/163; T3 IR, 54/163; HR, 1.61; 95% CI, 1.07–2.43) and fast‐paced 4‐meter walking velocity (T1 IR, 63/166; T3 IR, 44/166; HR, 1.75; 95% CI, 1.16, 2.64) were associated with higher mortality.

Conclusions

In people with peripheral artery disease, greater 1‐year decline in 6‐minute walk or 4‐meter walking velocity may help identify people with peripheral artery disease at highest risk for mobility loss and mortality.

Digital Disparities: Lessons learned from a Patient Reported Outcomes Program During the COVID-19 Pandemic

The collection of patient reported outcomes (PROs) allows us to incorporate the patient's voice within their care in a quantifiable, validated manner. Large scale collection of PROs is facilitated by the electronic health record (EHR) and its portal, though historically patients have eschewed the portal and completed patient reported outcome measures (PROMS) in clinic via tablet. Furthermore, access to and use of the portal is associated with known racial inequities. Our institution oversees the largest clinical PRO program in the world, and has a long history of racially equitable PRO completion rates via tablet. However, when the COVID-19 pandemic forced us to remove tablets from clinics and rely exclusively on portal use for PRO completion, profound racial disparities resulted immediately. Our experience quantifiably demonstrates the magnitude of inequity that the portal, in its current configuration, generates and serves as a cautionary tale to other health care systems and EHRs.