This Viewpoint discusses ways the coronavirus pandemic is threatening clinical trial conduct and enrollment, and suggests ways to adapt, including changes to how outcomes data are collected and how ...interventions are delivered and monitored, to minimize trial disruption, maximize trial benefit, and ensure patient health and safety during the pandemic.
The objective of this study was to provide an overview of evidence regarding exercise therapies for patients with lower extremity peripheral artery disease (PAD).
This manuscript summarizes the ...content of a lecture delivered as part of the 2016 Crawford Critical Issues Symposium.
Multiple randomized clinical trials demonstrate that supervised treadmill exercise significantly improves treadmill walking performance in people with PAD and intermittent claudication symptoms. A meta-analysis of 25 randomized trials demonstrated a 180-meter increase in treadmill walking distance in response to supervised exercise interventions compared with a nonexercising control group. Supervised treadmill exercise has been inaccessible to many patients with PAD because of lack of medical insurance coverage. However, in 2017, the Centers for Medicare and Medicaid Services issued a decision memorandum to support health insurance coverage of 12 weeks of supervised treadmill exercise for patients with walking impairment due to PAD. Recent evidence also supports home-based walking exercise to improve walking performance in people with PAD. Effective home-exercise programs incorporate behavioral change interventions such as a remote coach, goal setting, and self-monitoring. Supervised treadmill exercise programs preferentially improve treadmill walking performance, whereas home-based walking exercise programs preferentially improve corridor walking, such as the 6-minute walk test. Clinical trial evidence also supports arm or leg ergometry exercise to improve walking endurance in people with PAD. Treadmill walking exercise appears superior to resistance training alone for improving walking endurance.
Supervised treadmill exercise significantly improves treadmill walking performance in people with PAD by approximately 180 meters compared with no exercise. Recent evidence suggests that home-based exercise is also effective and preferentially improves over-ground walking performance, such as the 6-minute walk test.
IMPORTANCE: Lower extremity peripheral artery disease (PAD) affects approximately 8.5 million people in the US and approximately 230 million worldwide. OBSERVATIONS: Peripheral artery disease is ...uncommon before aged 50 years but affects up to 20% of people aged 80 years and older. It can be noninvasively diagnosed with the ankle-brachial index (ABI), a ratio of Doppler-recorded pressures in the dorsalis pedis and/or posterior tibial artery in each leg to brachial artery pressures. An ABI value less than 0.90 is 57% to 79% sensitive and 83% to 99% specific for arterial stenosis of at least 50%. Intermittent claudication, consisting of exertional calf pain that does not begin at rest and that resolves within 10 minutes of rest, is considered the classic symptom of PAD. However, 70% to 90% of people with an ABI value less than 0.90 either report no exertional leg symptoms (ie, asymptomatic) or report leg symptoms with walking that are not consistent with classic claudication. Over time, people with PAD restrict walking activity or slow walking speed to avoid leg symptoms. Thus, although approximately 75% of people with PAD report no change in leg symptoms over time, those with PAD have significantly greater annual declines in 6-minute walk performance compared with those without it. Approximately 11% of people with PAD develop chronic limb-threatening ischemia, the most severe form of PAD. Compared with people without PAD, those with the disease have approximately twice the rate of all-cause mortality, cardiovascular mortality, and major coronary events at 10-year follow-up. High-dose statins and antiplatelet therapy with or without antithrombotic therapy reduced rates of coronary events and stroke in people with PAD. Supervised treadmill exercise improved 6-minute walk distance by 30 to 35 m, consistent with a clinically meaningful change, whereas effective home-based walking exercise interventions improved 6-minute walk by 42 to 53 m. Effective home-based exercise programs require behavioral methods, including monitoring by a coach. CONCLUSIONS AND RELEVANCE: Peripheral artery disease affects approximately 230 million people worldwide and is associated with increased rates of cardiovascular events, lower extremity events, and functional decline compared with that of people without PAD. People with PAD should be treated with the highest dose of statin tolerated, antithrombotic and/or antiplatelet therapy, and exercise.
Summary Background Lower extremity peripheral artery disease is the third leading cause of atherosclerotic cardiovascular morbidity, following coronary artery disease and stroke. This study provides ...the first comparison of the prevalence of peripheral artery disease between high-income countries (HIC) and low-income or middle-income countries (LMIC), establishes the primary risk factors for peripheral artery disease in these settings, and estimates the number of people living with peripheral artery disease regionally and globally. Methods We did a systematic review of the literature on the prevalence of peripheral artery disease in which we searched for community-based studies since 1997 that defined peripheral artery disease as an ankle brachial index (ABI) lower than or equal to 0·90. We used epidemiological modelling to define age-specific and sex-specific prevalence rates in HIC and in LMIC and combined them with UN population numbers for 2000 and 2010 to estimate the global prevalence of peripheral artery disease. Within a subset of studies, we did meta-analyses of odds ratios (ORs) associated with 15 putative risk factors for peripheral artery disease to estimate their effect size in HIC and LMIC. We then used the risk factors to predict peripheral artery disease numbers in eight WHO regions (three HIC and five LMIC). Findings 34 studies satisfied the inclusion criteria, 22 from HIC and 12 from LMIC, including 112 027 participants, of which 9347 had peripheral artery disease. Sex-specific prevalence rates increased with age and were broadly similar in HIC and LMIC and in men and women. The prevalence in HIC at age 45–49 years was 5·28% (95% CI 3·38–8·17%) in women and 5·41% (3·41–8·49%) in men, and at age 85–89 years, it was 18·38% (11·16–28·76%) in women and 18·83% (12·03–28·25%) in men. Prevalence in men was lower in LMIC than in HIC (2·89% 2·04–4·07% at 45–49 years and 14·94% 9·58–22·56% at 85–89 years). In LMIC, rates were higher in women than in men, especially at younger ages (6·31% 4·86–8·15% of women aged 45–49 years). Smoking was an important risk factor in both HIC and LMIC, with meta-OR for current smoking of 2·72 (95% CI 2·39–3·09) in HIC and 1·42 (1·25–1·62) in LMIC, followed by diabetes (1·88 1·66–2·14 vs 1·47 1·29–1·68), hypertension (1·55 1·42–1·71 vs 1·36 1·24–1·50), and hypercholesterolaemia (1·19 1·07–1·33 vs 1·14 1·03–1·25). Globally, 202 million people were living with peripheral artery disease in 2010, 69·7% of them in LMIC, including 54·8 million in southeast Asia and 45·9 million in the western Pacific Region. During the preceding decade the number of individuals with peripheral artery disease increased by 28·7% in LMIC and 13·1% in HIC. Interpretation In the 21st century, peripheral artery disease has become a global problem. Governments, non-governmental organisations, and the private sector in LMIC need to address the social and economic consequences, and assess the best strategies for optimum treatment and prevention of this disease. Funding Peripheral Arterial Disease Research Coalition (Europe).
Lower extremity peripheral artery disease (PAD) affects >230 million adults worldwide and is associated with increased risk of various adverse clinical outcomes (other cardiovascular diseases such as ...coronary heart disease and stroke and leg outcomes such as amputation). Despite its prevalence and clinical importance, PAD has been historically underappreciated by health care professionals and patients. This underappreciation seems multifactorial (eg, limited availability of the first-line diagnostic test, the ankle-brachial index, in clinics; incorrect perceptions that a leg vascular disease is not fatal and that the diagnosis of PAD would not necessarily change clinical practice). In the past several years, a body of evidence has indicated that these perceptions are incorrect. Several studies have consistently demonstrated that many patients with PAD are not receiving evidence-based therapies. Thus, this scientific statement provides an update for health care professionals regarding contemporary epidemiology (eg, prevalence, temporal trends, risk factors, and complications) of PAD, the present status of diagnosis (physiological tests and imaging modalities), and the major gaps in the management of PAD (eg, medications, exercise therapy, and revascularization). The statement also lists key gaps in research, clinical practice, and implementation related to PAD. Orchestrated efforts among different parties (eg, health care providers, researchers, expert organizations, and health care organizations) will be needed to increase the awareness and understanding of PAD and improve the diagnostic approaches, management, and prognosis of PAD.
Understanding the minimal dose of physical activity required to achieve improvement in physical functioning and reductions in disability risk is necessary to inform public health recommendations. To ...examine the effect of physical activity dose on changes in physical functioning and the onset of major mobility disability in The Lifestyle Interventions and Independence for Elders (LIFE) Study. We conducted a multicenter single masked randomized controlled trial that enrolled participants in 2010 and 2011 and followed them for an average of 2.6 years. 1,635 sedentary men and women aged 70-89 years who had functional limitations were randomized to a structured moderate intensity walking, resistance, and flexibility physical activity program or a health education program. Physical activity dose was assessed by 7-day accelerometry and self-report at baseline and 24 months. Outcomes included the 400 m walk gait speed, the Short Physical Performance Battery (SPPB), assessed at baseline, 6, 12, and 24 months, and onset of major mobility disability (objectively defined by loss of ability to walk 400 m in 15 min). When the physical activity arm or the entire sample were stratified by change in physical activity from baseline to 24 months, there was a dose-dependent increase in the change in gait speed and SPPB from baseline at 6, 12, and 24 months. In addition, the magnitude of change in physical activity over 24 months was related to the reduction in the onset of major mobility disability (overall P < 0.001) (highest versus the lowest quartile of physical activity change HR 0.23 ((95% CI:0.10-0.52) P = 0.001) in the physical activity arm. We observed a dose-dependent effect of objectively monitored physical activity on physical functioning and onset of major mobility disability. Relatively small increases (> 48 minutes per week) in regular physical activity participation had significant and clinically meaningful effects on these outcomes.
ClinicalsTrials.gov NCT00116194.
McDermott discusses home-based walking exercise for peripheral artery disease. For approximately 30 years, supervised exercise therapy, typically consisting of walking for exercise on a treadmill at ...a health care facility in the presence of an exercise physiologist or nurse, has been first-line therapy for walking impairment in people disabled by lower extremity peripheral artery disease (PAD). In a meta-analysis of 25 randomized clinical trials (RCTs) that included 1054 participants with PAD, supervised walking exercise therapy was associated with an improvement in maximal treadmill walking distance of 180 m (95% CI, 130 m to 230 m) when compared with a control group that did not exercise. Currently, clinical practice guidelines from different countries and medical specialties unequivocally endorse supervised exercise as first-line therapy for PAD.
PURPOSE:To summarize evidence regarding exercise therapy for people with lower extremity peripheral artery disease (PAD).
METHODS:Literature was reviewed regarding optimal strategies for delivering ...exercise interventions for people with PAD. Randomized trial evidence and recent studies were emphasized.
RESULTS:Randomized clinical trial evidence consistently demonstrates that supervised treadmill exercise improves treadmill walking performance in people with PAD. A meta-analysis of 25 randomized trials (1054 participants) concluded that supervised treadmill exercise was associated with 180 m of improvement in maximal treadmill walking distance and 128 m of improvement in pain-free walking distance compared with a control group. Three randomized trials of 493 patients with PAD demonstrated that home-based walking exercise interventions that incorporate behavioral change techniques improve walking ability in patients with PAD. Furthermore, evidence suggests that home-based walking exercise improves the 6-min walk more than supervised treadmill exercise. Upper and lower extremity ergometry also significantly improved walking endurance in PAD. The Centers for Medicare & Medicaid Services recently determined that Medicare would cover 12 wk (36 sessions) of supervised treadmill exercise for patients with PAD.
CONCLUSIONS:Supervised treadmill exercise and home-based walking exercise each improve walking ability in patients with PAD. The availability of insurance coverage for supervised treadmill exercise for patients with PAD will make supervised treadmill exercise more widely available and accessible. Home-based exercise that incorporates behavioral change technique is an effective alternative for patients unwilling or unable to attend 3 supervised exercise sessions per week.
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