2024 ACC/AHA/AACVPR/APMA/ABC/SCAI/SVM/SVN/SVS/SIR/VESS Guideline for the Management of Lower Extremity Peripheral Artery Disease: A Report of the American College of Cardiology/American Heart Association Joint Committee on Clinical Practice Guidelines.

AIM: The "2024 ACC/AHA/AACVPR/APMA/ABC/SCAI/SVM/SVN/SVS/SIR/VESS Guideline for the Management of Lower Extremity Peripheral Artery Disease" provides recommendations to guide clinicians in the treatment of patients with lower extremity peripheral artery disease across its multiple clinical presentation subsets (ie, asymptomatic, chronic symptomatic, chronic limb-threatening ischemia, and acute limb ischemia). METHODS: A comprehensive literature search was conducted from October 2020 to June 2022, encompassing studies, reviews, and other evidence conducted on human subjects that was published in English from PubMed, EMBASE, the Cochrane Library, CINHL Complete, and other selected databases relevant to this guideline. Additional relevant studies, published through May 2023 during the peer review process, were also considered by the writing committee and added to the evidence tables where appropriate. STRUCTURE: Recommendations from the "2016 AHA/ACC Guideline on the Management of Patients With Lower Extremity Peripheral Artery Disease" have been updated with new evidence to guide clinicians. In addition, new recommendations addressing comprehensive care for patients with peripheral artery disease have been developed.

Health Disparities in Peripheral Artery Disease: A Scientific Statement From the American Heart Association.

Peripheral artery disease (PAD) affects 200 million individuals worldwide. In the United States, certain demographic groups experience a disproportionately higher prevalence and clinical effect of PAD. The social and clinical effect of PAD includes higher rates of individual disability, depression, minor and major limb amputation along with cardiovascular and cerebrovascular events. The reasons behind the inequitable burden of PAD and inequitable delivery of care are both multifactorial and complex in nature, including systemic and structural inequity that exists within our society. Herein, we present an overview statement of the myriad variables that contribute to PAD disparities and conclude with a summary of potential novel solutions.

Uptake and outcomes of supervised exercise therapy for peripheral artery disease: The importance of vascular medicine specialists at a large midwestern health care system during the first 5 years of CMS reimbursement.

BACKGROUND: Supervised exercise therapy (SET) is the cornerstone of medical therapy for symptomatic peripheral artery disease (PAD). Despite the efficacy of SET, initial reports following the 2017 Centers for Medicare and Medicaid Services (CMS) reimbursement decision indicate low SET uptake, referral, and completion. Vascular medicine specialists are key to the success of such programs. We examined rates of SET referral, completion, and outcomes in a health system with a robust SET program during the first 5 years of CMS reimbursement. METHODS: A retrospective chart review of patients with PAD referred to SET between October 1, 2017 and December 31, 2022 was conducted. Patient demographic and medical characteristics, SET indication, referring provider specialty, SET participation (e.g., exercise modality, number of sessions, treadmill prescription), and outcomes were abstracted. Descriptive statistics, t-tests, and multiple linear regression were used to examine the sample, evaluate outcomes, and explore outcomes by relevant covariates (i.e., age, sex, referring provider specialty). RESULTS: Of 5320 patients with PAD, N = 773 were referred to SET; N = 415 enrolled and were included in the present study. Vascular medicine and vascular surgery specialists were the two primary sources of referrals (30.6% and 51.6%, respectively). A total of 207 patients (49.9%) completed SET. Statistically significant and clinically meaningful improvements were observed in all outcomes. CONCLUSION: SET referral and completion rates are low in the 5 years following CMS reimbursement, despite the advocacy of vascular medicine specialists. SET is effective in improving patient functional capacity and quality of life. Additional efforts are needed to increase both SET availability and referrals as part of comprehensive treatment of PAD.

Characterizing patient-reported claudication treatment goals to support patient-centered treatment selection and measurement strategies.

OBJECTIVE: Patient-reported outcomes (PRO) have been increasingly emphasized for peripheral artery disease (PAD). Patient-defined treatment goals and expectations, however, are poorly understood and might not be achievable or aligned with guidelines or clinical outcomes. We evaluated the patient-reported treatment goals among patients with claudication and the associations between patient characteristics, goals, and PAD-specific PRO scores. METHODS: Patients with a diagnosis of claudication were prospectively recruited. Patient-defined treatment goals and outcomes related to walking distance, duration, and speed were quantified using multiple-choice survey items. Free-text items were used to identify activities other than walking distance, duration, or speed associated with symptoms and treatment goals. The peripheral artery disease quality of life and walking impairment questionnaire instruments were included as PRO. The treatment goal categories were compared with the PRO percentile scores using 95% confidence intervals (CIs), categorical tests, and logistic regression models. Associations between the patient characteristics and PRO were evaluated using linear and ordinal logistic regression models. RESULTS: A total of 150 patients meeting the inclusion criteria were included in the present study. Of these 150 patients, 144 (96%) viewed the entire survey. Their mean age was 70.0 ± 11.3 years, and 32.9% were women. Most of the respondents had self-reported their race as White (n = 135), followed by Black (n = 3), Asian (n = 2), Native American (n = 2), and other/unknown (n = 2). Two participants self-reported Hispanic ethnicity. The primary treatment goals were an increased walking distance or duration without stopping (62.0%), the ability to perform a specific activity or task (23.0%), an increased walking speed (8.0%), or other/none of the above (7.0%). The specific activities associated with symptoms or goals included outdoor recreation (38.5%), labor-related tasks (30.7%), sports (26.9%), climbing stairs (23.1%), uphill walking (19.2%), and shopping (6%). Among the patients choosing an increased walking distance and duration as the primary goals, 64% had indicated that a distance of ≥0.5 mile (2640 ft) and 59% had indicated a duration of ≥30 minutes would be a minimum increase consistent with meaningful improvement. Increasing age was associated with lower odds of a distance improvement goal of ≥0.5 mile (odds ratio [OR], 0.68 per 5 years; 95% CI, 0.51-0.92; P = .012) or duration improvement goal of ≥30 minutes (OR, 0.76 per 5 years; 95% CI, 0.58-0.99; P = .047). Patient characteristics associated with PAD Quality of Life percentile scores included age, ankle brachial index, and gender. Ankle brachial index was the only patient characteristic associated with the walking impairment questionnaire percentile scores. CONCLUSIONS: Patients define treatment goals according to their desired activities and expectations, which may influence their goals and perceived outcomes. Patients' expectations of minimum increases in walking distance and duration consistent with meaningful improvement exceeded reported minimum important difference criteria for many patients and would not be captured using common clinic-based walking tests. Patient age was associated with both treatment goals and PRO scores, and the related floor and ceiling effects could influence sensitivity to PRO changes for younger and older patients, respectively. Heterogeneity in treatment goals supports consideration of tailored decision-making and outcomes informed by patient characteristics and perspectives.

Barriers to participation in supervised exercise therapy reported by people with peripheral artery disease.

OBJECTIVE: This study identified barriers to participation in supervised exercise therapy covered by the Centers for Medicare and Medicaid Services (CMS), reported by people with lower extremity peripheral artery disease (PAD). METHODS: People with PAD participating in research studies of walking impairment due to PAD in the Chicagoland area were asked to complete a questionnaire between March 15, 2019, and July 12, 2022, assessing their experience and attitudes about supervised exercise therapy. Participants were identified using mailed postcards to people aged 50 and older in Chicagoland, from medical centers in Chicago, and using bus and train advertisements. The questionnaire was developed based on focus group feedback from people with PAD. RESULTS: Of 516 participants with PAD approached, 489 (94.8%) completed the questionnaire (mean age: 71.0 years [standard deviation: 8.7], mean ankle-brachial index: 0.71 [standard deviation: 0.25]; 204 [41.7%] women and 261 [53.4%] Black). Of the 489 participants, 416 (85.1%) reported that their physician had never prescribed or recommended supervised exercise therapy. Overall, 357 (73.2%) reported willingness to travel three times weekly to the medical center for supervised exercise participation. However, of these, 214 (59.9%) reported that they were unwilling or unable to pay the $11 per exercise session copay required for supervised exercise covered by CMS. Of 51 people with PAD who reported prior participation in supervised exercise, only 5 (9.8%) completed the 12 weeks of supervised exercise therapy covered by CMS and 29 (56.9%) completed 6 or fewer weeks. Of 131 (26.8%) unwilling to travel three times weekly to a center for supervised exercise, the most common reasons for unwillingness to participate were "too time-consuming" (55.0%), "too inconvenient" (45.8%), and "lack of interest in treadmill exercise" (28.2%). CONCLUSIONS: Approximately 2 to 4 years after CMS began covering supervised exercise for PAD, most people with PAD in this study from a large urban area had not participated in supervised exercise therapy. Of those who participated, most completed fewer than half of the sessions covered by CMS. The required CMS copayment was a common barrier to supervised exercise participation by people with PAD.

Total body recumbent stepping vs treadmill walking in supervised exercise therapy: A pilot study.

Background: Treadmill walking is the most commonly recommended exercise modality in supervised exercise therapy (SET) for peripheral artery disease (PAD); however, other modalities may be equally effective and more tolerable for patients. The primary aim of this single-blind, randomized pilot study was to compare the feasibility, safety, and preliminary efficacy of a treadmill walking (TM) versus a total body recumbent stepping (TBRS) exercise program for treatment of PAD (i.e., "Stepper Study").. Methods: Participants (n = 19) enrolled in a 12-week SET program and were randomized to either a TM (n = 9) or TBRS (n = 10) exercise group that followed current SET exercise guidelines. Feasibility, safety, and efficacy outcomes were assessed. Results: SET attendance was 86% and 71%, respectively, for TBRS and TM groups (p = 0.07). Session exercise dose (metabolic equivalents of task [MET] minutes) (mean [SD]) for TM was 117.6 [27.4] compared to 144.7 [28.7] in the TBRS group (p = 0.08). Study-related adverse events were nine in 236 training hours and three in 180 training hours for the TBRS and TM groups, respectively. There were no significant differences between groups for improvement in 6-minute walk distance (mean [SD]) (TM: 133.2 ft [53.5] vs TBRS: 154.8 ft [49.8]; p = 0.77) after adjusting for baseline 6-minute walk distance. Conclusion: This is the first randomized study comparing TBRS to TM exercise in SET using current SET guidelines. This pilot study showed that TBRS is a feasible and safe exercise modality in SET. This study provides preliminary efficacy of the use of TBRS exercise in SET programs following current guidelines. Larger studies should be conducted to confirm these findings.

Decision Aids for Determining Facility Versus Non-Facility-Based Exercise in Those with Symptomatic Peripheral Artery Disease.

PURPOSE OF REVIEW: This paper sought to provide rationale for determining when a patient with symptomatic peripheral artery disease (PAD) might be referred for home-based versus facility-based exercise therapy. RECENT FINDINGS: Multiple randomized controlled studies have embedded supervised, structured exercise therapy as a class IA recommended therapy for those with symptomatic PAD. More recently, there is interest in non-facility-based exercise training as an alternative. The current literature is mixed on the effectiveness of non-facility-based training and is influenced by the amount of contact with clinical staff providing some supervision (e.g., occasional facility-based exercise or coaching phone calls), and the intensity (e.g., performed intermittently by inducing pain or continually and not inducing pain) and frequency (e.g., 12-week common supervised exercise program or those longer than 24 weeks) of exercise. Certainly, the data suggests non-facility-based exercise, while possibly improving walking performance, is inferior to facility-based supervised exercise training. Comprehensive data is lacking on utilization of supervised exercise therapy in those with symptomatic PAD, but is likely <2% of those eligible who participate. This suggests a possible important role for alternatives including non-facility-based (e.g., home, fitness center). Exercise training in the supervised, facility-based setting appears to be greatly underutilized. Non-facility-based exercise may help to overcome some of the most common barriers to participating in facility-based exercise including those related to motivation, transportation, and proximity. However, facility-based training is considered the gold standard so decisions about allowing a patient to exercise train at home must take into account issues including disease severity, patient motivation and available exercise resources, mobility and balance, cognitive function, and other medical concerns (e.g., symptomatic coronary artery disease or heart failure).

Sustained physical activity in peripheral artery disease: Associations with disease severity, functional performance, health-related quality of life, and subsequent serious adverse events in the LITE randomized clinical trial.

This study investigated cross-sectional associations of peripheral artery disease (PAD) severity (defined by the ankle-brachial index (ABI)) and amounts of daily sustained physical activity (PA) (defined as > 100 activity counts per minute lasting 5 consecutive minutes or more). This study also investigated associations of amounts of daily sustained PA with 6-minute walk (6MW) distance and the Short Form-36 physical functioning domain (SF-36 PF) score in cross-sectional analyses and with serious adverse events (SAEs) in longitudinal analyses of people with PAD. PA was measured continuously for 10 days using a tri-axial accelerometer at baseline in 277 participants with PAD randomized to the LITE clinical trial. In regression analyses, each 0.15 lower ABI value was associated with a 5.67% decrease in the number of daily bouts of sustained PA (95% CI: 3.85-6.54; p < 0.001). Every additional bout of sustained PA per day was associated with a 4.56-meter greater 6MW distance (95% CI: 2.67-6.46; p < 0.0001), and a 0.81-point improvement in SF-36 PF score (95% CI: 0.34-1.28; p < 0.001). Participants with values of daily bouts of sustained PA below the median had higher rates of SAEs during follow-up, compared to participants above the median (41% vs 24%; p = 0.002). In conclusion, among participants with PAD, lower ABI values were associated with fewer bouts of daily sustained PA. A greater number of bouts of daily sustained PA were associated with better 6MW performance and SF-36 PF score, and, in longitudinal analyses, lower rates of SAEs. Clinicaltrials.gov ID: NCT02538900.

Effect of Low-Intensity vs High-Intensity Home-Based Walking Exercise on Walk Distance in Patients With Peripheral Artery Disease: The LITE Randomized Clinical Trial.

Importance: Supervised high-intensity walking exercise that induces ischemic leg symptoms is the first-line therapy for people with lower-extremity peripheral artery disease (PAD), but adherence is poor. Objective: To determine whether low-intensity home-based walking exercise at a comfortable pace significantly improves walking ability in people with PAD vs high-intensity home-based walking exercise that induces ischemic leg symptoms and vs a nonexercise control. Design, Setting, and Participants: Multicenter randomized clinical trial conducted at 4 US centers and including 305 participants. Enrollment occurred between September 25, 2015, and December 11, 2019; final follow-up was October 7, 2020. Interventions: Participants with PAD were randomized to low-intensity walking exercise (n = 116), high-intensity walking exercise (n = 124), or nonexercise control (n = 65) for 12 months. Both exercise groups were asked to walk for exercise in an unsupervised setting 5 times per week for up to 50 minutes per session wearing an accelerometer to document exercise intensity and time. The low-intensity group walked at a pace without ischemic leg symptoms. The high-intensity group walked at a pace eliciting moderate to severe ischemic leg symptoms. Accelerometer data were viewable to a coach who telephoned participants weekly for 12 months and helped them adhere to their prescribed exercise. The nonexercise control group received weekly educational telephone calls for 12 months. Main Outcomes and Measures: The primary outcome was mean change in 6-minute walk distance at 12 months (minimum clinically important difference, 8-20 m). Results: Among 305 randomized patients (mean age, 69.3 [SD, 9.5] years, 146 [47.9%] women, 181 [59.3%] Black patients), 250 (82%) completed 12-month follow-up. The 6-minute walk distance changed from 332.1 m at baseline to 327.5 m at 12-month follow-up in the low-intensity exercise group (within-group mean change, -6.4 m [95% CI, -21.5 to 8.8 m]; P = .34) and from 338.1 m to 371.2 m in the high-intensity exercise group (within-group mean change, 34.5 m [95% CI, 20.1 to 48.9 m]; P < .001) and the mean change for the between-group comparison was -40.9 m (97.5% CI, -61.7 to -20.0 m; P < .001). The 6-minute walk distance changed from 328.1 m at baseline to 317.5 m at 12-month follow-up in the nonexercise control group (within-group mean change, -15.1 m [95% CI, -35.8 to 5.7 m]; P = .10), which was not significantly different from the change in the low-intensity exercise group (between-group mean change, 8.7 m [97.5% CI, -17.0 to 34.4 m]; P = .44). Of 184 serious adverse events, the event rate per participant was 0.64 in the low-intensity group, 0.65 in the high-intensity group, and 0.46 in the nonexercise control group. One serious adverse event in each exercise group was related to study participation. Conclusions and Relevance: Among patients with PAD, low-intensity home-based exercise was significantly less effective than high-intensity home-based exercise and was not significantly different from the nonexercise control for improving 6-minute walk distance. These results do not support the use of low-intensity home-based walking exercise for improving objectively measured walking performance in patients with PAD. Trial Registration: ClinicalTrials.gov Identifier: NCT02538900.

Implementation of Supervised Exercise Therapy for Patients With Symptomatic Peripheral Artery Disease: A Science Advisory From the American Heart Association.

Patients with lower-extremity peripheral artery disease (PAD) have greater functional impairment, faster functional decline, increased rates of mobility loss, and poorer quality of life than people without PAD. Supervised exercise therapy (SET) improves walking ability, overall functional status, and health-related quality of life in patients with symptomatic PAD. In 2017, the Centers for Medicare & Medicaid Services released a National Coverage Determination (CAG-00449N) for SET programs for patients with symptomatic PAD. This advisory provides a practical guide for delivering SET programs to patients with PAD according to Centers for Medicare & Medicaid Services criteria. It summarizes the Centers for Medicare & Medicaid Services process and requirements for referral and coverage of SET and provides guidance on how to implement SET for patients with PAD, including the SET protocol, options for outcome measurement, and transition to home-based exercise. This advisory is based on the guidelines established by the Centers for Medicare & Medicaid Services for Medicare beneficiaries in the United States and is intended to assist clinicians and administrators who are implementing SET programs for patients with PAD.

Cardio-Oncology Rehabilitation to Manage Cardiovascular Outcomes in Cancer Patients and Survivors: A Scientific Statement From the American Heart Association.

Cardiovascular disease is a competing cause of death in patients with cancer with early-stage disease. This elevated cardiovascular disease risk is thought to derive from both the direct effects of cancer therapies and the accumulation of risk factors such as hypertension, weight gain, cigarette smoking, and loss of cardiorespiratory fitness. Effective and viable strategies are needed to mitigate cardiovascular disease risk in this population; a multimodal model such as cardiac rehabilitation may be a potential solution. This statement from the American Heart Association provides an overview of the existing knowledge and rationale for the use of cardiac rehabilitation to provide structured exercise and ancillary services to cancer patients and survivors. This document introduces the concept of cardio-oncology rehabilitation, which includes identification of patients with cancer at high risk for cardiac dysfunction and a description of the cardiac rehabilitation infrastructure needed to address the unique exposures and complications related to cancer care. In this statement, we also discuss the need for future research to fully implement a multimodal model of cardiac rehabilitation for patients with cancer and to determine whether reimbursement of these services is clinically warranted.

Influence of Changes in Sedentary Time on Outcomes of Supervised Exercise Therapy in Individuals with Comorbid Peripheral Artery Disease and Type 2 Diabetes.

BACKGROUND: Although supervised exercise therapy (SET) is effective in improving walking distance among adults with symptomatic peripheral artery disease (PAD), some research suggests that individuals with comorbid PAD and type 2 diabetes mellitus (T2DM) may experience a blunted response to SET. It is unknown whether free-living sedentary time changes during SET, and if increases in sedentary time could, in part, explain poor response to SET. The purposes of this pilot study were to (1) determine if older adults with PAD (with and without T2DM) engaging in SET change their sedentary behavior and (2) examine the relationship between changes in sedentary behavior and SET outcomes. We hypothesized that decreased sedentary time during SET would be associated with greater improvements in six-minute walk test (6MWT) total distance and other key SET outcomes. METHODS: Participants (n = 44) initiating a 12-week SET program completed the 6MWT, Short Physical Performance Battery, Walking Impairment Questionnaire, and accelerometer-assessed sedentary behavior at SET initiation, 6 weeks, and 12 weeks. RESULTS: Participants' mean age was 72.3 (7.1) years, mean ankle-brachial index was 0.71 (0.25), and 47.7% were female. On average, sedentary time did not change after SET, although there was substantial variability (-40% to +38% change in minutes of sedentary time/day). Participants with T2DM experienced greater improvements in claudication onset distance than participants without T2DM (mean = 35 m, P = 0.044, 95% confidence interval = 1.6 to 115.4 m). Neither changes in sedentary time from baseline to 6 weeks (P = 0.419) nor T2DM (P = 0.154) predicted changes in 6MWT total distance from baseline to 12 weeks. CONCLUSIONS: As SET availability increases, further examination of factors that may influence SET outcomes will help maximize benefits of this proven therapy.

Measurement of peripheral blood flow in patients with peripheral artery disease: Methods and considerations.

Peripheral artery disease (PAD) is a manifestation of generalized atherosclerosis which results in hemodynamic compromise of oxygen and substrate delivery to the lower extremity skeletal muscles. Hemodynamic assessments are vital in PAD diagnosis and in the evaluation of strategies aimed at treating claudication (i.e. exercise training, revascularization, and pharmacological agents). Venous occlusion plethysmography (VOP) is a century-old, non-invasive technique used to quantify limb blood flow and has been used to evaluate hemodynamic compromise in patients with PAD. However, the literature suggests a wide array of methodological variability in the measurement and analysis of limb blood flow using VOP. In this manuscript, we overview the clinical application of VOP measurement, and secondly we review the methodological variation that occurs during the measurement and analysis of VOP in healthy individuals and in patients with claudication.

Effect of a Home-Based Exercise Intervention of Wearable Technology and Telephone Coaching on Walking Performance in Peripheral Artery Disease: The HONOR Randomized Clinical Trial.

Importance: Clinical practice guidelines support home-based exercise for patients with peripheral artery disease (PAD), but no randomized trials have tested whether an exercise intervention without periodic medical center visits improves walking performance. Objective: To determine whether a home-based exercise intervention consisting of a wearable activity monitor and telephone coaching improves walking ability over 9 months in patients with PAD. Design, Setting, and Participants: Randomized clinical trial conducted at 3 US medical centers. Patients with PAD were randomized between June 18, 2015, and April 4, 2017, to home-based exercise vs usual care for 9 months. Final follow-up was on December 5, 2017. Interventions: The exercise intervention group (n = 99) received 4 weekly medical center visits during the first month followed by 8 months of a wearable activity monitor and telephone coaching. The usual care group (n = 101) received no onsite sessions, active exercise, or coaching intervention. Main Outcomes and Measures: The primary outcome was change in 6-minute walk distance at 9-month follow-up (minimal clinically important difference [MCID], 20 m). Secondary outcomes included 9-month change in subcomponents of the Walking Impairment Questionnaire (WIQ) (0-100 score; 100, best), SF-36 physical functioning score, Patient-Reported Outcomes Measurement Information System (PROMIS) mobility questionnaire (higher = better; MCID, 2 points), PROMIS satisfaction with social roles questionnaire, PROMIS pain interference questionnaire (lower = better; MCID range, 3.5-4.5 points), and objectively measured physical activity. Results: Among 200 randomized participants (mean [SD] age, 70.2 [10.4] years; 105 [52.5%] women), 182 (91%) completed 9-month follow-up. The mean change from baseline to 9-month follow-up in the 6-minute walk distance was 5.5 m in the intervention group vs 14.4 m in the usual care group (difference, -8.9 m; 95% CI, -26.0 to 8.2 m; P = .31). The exercise intervention worsened the PROMIS pain interference score, mean change from baseline to 9 months was 0.7 in the intervention group vs -2.8 in the usual care group (difference, 3.5; 95% CI, 1.3 to 5.8; P = .002). There were no significant between-group differences in the WIQ score, the SF-36 physical functioning score, or the PROMIS mobility or satisfaction with social roles scores. Conclusions and Relevance: Among patients with PAD, a home-based exercise intervention consisting of a wearable activity monitor and telephone coaching, compared with usual care, did not improve walking performance at 9-month follow-up. These results do not support home-based exercise interventions of wearable devices and telephone counseling without periodic onsite visits to improve walking performance in patients with PAD. Trial Registration: clinicaltrials.gov Identifier: NCT02462824.

Variability in Individual Response to Aerobic Exercise Interventions Among Older Adults.

Although a plethora of evidence supports the benefits of exercise among older adults, a majority of studies have emphasized group differences, while giving little, if any, attention to individual differences. Given the lack of data on variability in response, the present review examined how nonresponse to aerobic exercise has been defined in older adult populations and characteristics associated with nonresponse among older adults. The results of this review suggest that interindividual variability in response of maximal oxygen consumption to aerobic exercise interventions is prevalent among older adults (1.4-63.4%); age, sex, race, and body mass index may not be critical determinants of nonresponse; whereas health status, baseline fitness, and exercise dose appear important. Future intervention studies should evaluate and report the variability in individual response of older adults to exercise; investigators should develop programs that allow for modification of components to assist older adults in achieving optimal benefit from exercise programs.

The Relationship Between Peripheral Artery Disease Symptomatology and Ischemia.

BACKGROUND: Fewer than half of individuals with peripheral artery disease (PAD) experience classic claudication, and the relationships between PAD typical or atypical symptom intensity, location, and description (classic or atypical) with ischemic changes have not previously been reported. OBJECTIVE: The primary purpose of this study was to evaluate the relationship between self-reported PAD symptom intensity and calf tissue ischemia measured using the tissue saturation index (TSI) during treadmill exercise. The location and descriptors of atypical PAD symptoms in the presence of calf tissue ischemia were also identified. METHODS: Adults with PAD with exercise-limiting ischemic symptoms were asked to (a) rate symptom intensity using a numerical rating scale (NRS) from 0 to 5 (0 = no pain, 1 = onset of pain, 5 = maximal pain), (b) provide symptom locations and descriptors, and (c) wear a near-infrared spectroscopy device to obtain calf TSI values during treadmill exercise. Multilevel models with TSI as the outcome variable were estimated during exercise and recovery. Covariates included were exercise time, recovery time, baseline TSI, exercise rating, recovery rating, ankle-brachial index (ABI), age, race, gender, body mass index, diabetes, neuropathy, and smoking. RESULTS: During three successive bouts of treadmill exercise for 40 participants (80% Caucasian men; average age = 68 years, SD = 9.2), the most rapid decline in TSI occurred between the start of exercise and symptom onset (when NRS = 1). The TSI nadir was often reached prior to report of maximum discomfort (when NRS = 5), and changes in TSI were related to exercise time (p < .001), baseline TSI (p < .001), exercise ratings (p < .001), and ABI (p < .05). During recovery, TSI increased steadily for most participants as pain eased. In the recovery model, changes in TSI were associated with recovery ratings (p < .001) and ABI (p < .03). Of 120 treadmill exercise tests, 69.2% were stopped due to discomfort in the calf with classic descriptors reported only half the time (55.4%). DISCUSSION: Exploratory analyses revealed ischemic symptoms extended beyond classic claudication locations and descriptors. Future research should evaluate changes in TSI relative to atypical locations and descriptors to improve understanding of the full range of ischemic symptoms experienced by individuals with PAD.