Heat therapy reduces blood pressure and circulating endothelin‐1 levels, but does not improve walking performance or vascular function in patients with symptomatic peripheral artery disease

This is the first sham-controlled study to investigate the effects of leg heat therapy (HT) on walking performance, vascular function, and quality of life in patients with peripheral artery disease (PAD). Adherence to HT was high, and the treatment was well tolerated. Our findings revealed that HT applied with water-circulating trousers evokes a clinically meaningful increase in perceived physical function and reduces the serum concentration of the potent vasoconstrictor endothelin-1 in patients with PAD.

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Acute effects of leg heat therapy on walking performance and cardiovascular and inflammatory responses to exercise in patients with peripheral artery disease

Physiological Reports ◽

10.14814/phy2.14650 ◽

2020 ◽

Vol 8 (24) ◽

Author(s):

Jacob C. Monroe ◽

Qifan Song ◽

Michael S. Emery ◽

Daniel M. Hirai ◽

Raghu L. Motaganahalli ◽

...

Keyword(s):

Peripheral Artery Disease ◽

Inflammatory Responses ◽

Acute Effects ◽

Peripheral Artery ◽

Heat Therapy ◽

Walking Performance ◽

Artery Disease

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Thermotherapy reduces blood pressure and circulating endothelin-1 concentration and enhances leg blood flow in patients with symptomatic peripheral artery disease

AJP Regulatory Integrative and Comparative Physiology ◽

10.1152/ajpregu.00147.2016 ◽

2016 ◽

Vol 311 (2) ◽

pp. R392-R400 ◽

Cited By ~ 22

Author(s):

Dustin Neff ◽

Alisha M. Kuhlenhoelter ◽

Chen Lin ◽

Brett J. Wong ◽

Raghu L. Motaganahalli ◽

...

Keyword(s):

Blood Pressure ◽

Blood Flow ◽

Peripheral Artery Disease ◽

Popliteal Artery ◽

Peripheral Artery ◽

Leg Blood Flow ◽

Endothelin 1 ◽

Control Intervention ◽

Artery Disease ◽

The Impact

Leg thermotherapy (TT) application reduces blood pressure (BP) and increases both limb blood flow and circulating levels of anti-inflammatory mediators in healthy, young humans and animals. The purpose of the present study was to determine the impact of TT application using a water-circulating garment on leg and systemic hemodynamics and on the concentrations of circulating cytokines and vasoactive mediators in patients with symptomatic peripheral artery disease (PAD). Sixteen patients with PAD and intermittent claudication (age: 63 ± 9 yr) completed three experimental sessions in a randomized order: TT, control intervention, and one exercise testing session. The garment was perfused with 48°C water for 90 min in the TT session and with 33°C water in the control intervention. A subset of 10 patients also underwent a protocol for the measurement of blood flow in the popliteal artery during 90 min of TT using phase-contrast MRI. Compared with the control intervention, TT promoted a significant reduction in systolic (∼11 mmHg) and diastolic (∼6 mmHg) BP ( P < 0.05) that persisted for nearly 2 h after the end of the treatment. The serum concentration of endothelin-1 (ET-1) was significantly lower 30 min after exposure to TT (Control: 2.3 ± 0.1 vs. TT: 1.9 ± 0.09 pg/ml, P = 0.026). In addition, TT induced a marked increase in peak blood flow velocity (∼68%), average velocity (∼76%), and average blood flow (∼102%) in the popliteal artery ( P < 0.01). These findings indicate that TT is a practical and effective strategy to reduce BP and circulating ET-1 concentration and enhance leg blood flow in patients with PAD.

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Supervised exercise therapy, blood pressure and heart rate during exercise, and functional impairment in Peripheral Artery Disease: results of a randomized clinical trial

Journal of Vascular Surgery ◽

10.1016/j.jvs.2021.05.033 ◽

2021 ◽

Author(s):

Joshua T. Slysz ◽

Lu Tian ◽

Lihui Zhao ◽

Dongxue Zhang ◽

Mary M. McDermott

Keyword(s):

Blood Pressure ◽

Clinical Trial ◽

Heart Rate ◽

Randomized Clinical Trial ◽

Peripheral Artery Disease ◽

Exercise Therapy ◽

Functional Impairment ◽

Peripheral Artery ◽

Supervised Exercise ◽

Artery Disease

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Abstract 11: Effects of Canakinumab in Patients With Peripheral Artery Disease

Arteriosclerosis Thrombosis and Vascular Biology ◽

10.1161/atvb.37.suppl_1.11 ◽

2017 ◽

Vol 37 (suppl_1) ◽

Author(s):

Kerry S Russell ◽

Denise Yates ◽

Andrea Feller ◽

Tianke Wang ◽

Ping Chen ◽

...

Keyword(s):

Peripheral Artery Disease ◽

Vascular Function ◽

Cardiovascular Events ◽

Ankle Brachial Index ◽

Unmet Need ◽

Walking Distance ◽

Plaque Progression ◽

Peripheral Artery ◽

Plaque Volume ◽

Artery Disease

Background: Peripheral artery disease (PAD) affects 8.5 million people in the US. PAD patients are at high risk for cardiovascular events, and their quality of life is often significantly impaired by decreased mobility. Interleukin-1β (IL-1β) may play an important role in this disease by promoting inflammatory responses that drive atherosclerotic plaque progression and impair vascular function. We sought to test whether interruption of IL-1β signaling would improve patient mobility and decrease plaque progression in the lower extremities. Methods: 38 patients (mean age 65; 71% male) with symptomatic PAD (confirmed by ankle-brachial index) were randomized 1:1 to receive Canakinumab (150 mg subcutaneously) or placebo monthly for up to 12 months. Plaque volume in the superficial femoral artery (SFA) was assessed serially using 3.0T MRI. Mobility was assessed serially using the 6-minute walk test (maximum and pain-free walking distance). Results: Canakinumab was safe and well-tolerated. 12 patients discontinued (8 placebo, 4 Canakinumab). MRI data (from 31 patients at 3 months; 21 patients at 12 months) showed no evidence of plaque progression in the SFA at either time point in placebo-treated patients; nor was there a change in plaque volume in the Canakinumab-treated group. There was a serial and significant improvement in placebo-adjusted maximum and pain-free walking distance observed as early as 3 months after treatment with Canakinumab (58-meter improvement over placebo in pain-free distance at 3 months, P=0.01). Two placebo-treated patients required peripheral vascular interventions due to progression of disease; however, no Canakinumab-treated patients required revascularization during the study. Canakinumab decreased markers of systemic inflammation (IL-6 and hsCRP). Conclusions: Treatment with Canakinumab may improve maximum and pain-free walk distance in patients with symptomatic PAD. In conjunction with results soon to be reported for the CANTOS trial of Canakinumab for secondary prevention of cardiovascular events, additional studies may provide support that inhibition of IL-1β signaling can improve symptoms and function in this patient population with high unmet need.

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Chronic femoral artery ligation exaggerates the pressor and sympathetic nerve responses during dynamic skeletal muscle stretch in decerebrate rats

AJP Heart and Circulatory Physiology ◽

10.1152/ajpheart.00498.2017 ◽

2018 ◽

Vol 314 (2) ◽

pp. H246-H254 ◽

Cited By ~ 6

Author(s):

Evan A. Kempf ◽

Korynne S. Rollins ◽

Tyler D. Hopkins ◽

Alec L. Butenas ◽

Joseph M. Santin ◽

...

Keyword(s):

Blood Pressure ◽

Peripheral Artery Disease ◽

Sympathetic Nerve ◽

Sympathetic Nerve Activity ◽

Peripheral Artery ◽

Nerve Activity ◽

Exercise Pressor Reflex ◽

Pressor Reflex ◽

Artery Disease ◽

Dynamic Stretch

Mechanical and metabolic signals arising during skeletal muscle contraction reflexly increase sympathetic nerve activity and blood pressure (i.e., the exercise pressor reflex). In a rat model of simulated peripheral artery disease in which a femoral artery is chronically (~72 h) ligated, the mechanically sensitive component of the exercise pressor reflex during 1-Hz dynamic contraction is exaggerated compared with that found in normal rats. Whether this is due to an enhanced acute sensitization of mechanoreceptors by metabolites produced during contraction or involves a chronic sensitization of mechanoreceptors is unknown. To investigate this issue, in decerebrate, unanesthetized rats, we tested the hypothesis that the increases in mean arterial blood pressure and renal sympathetic nerve activity during 1-Hz dynamic stretch are larger when evoked from a previously “ligated” hindlimb compared with those evoked from the contralateral “freely perfused” hindlimb. Dynamic stretch provided a mechanical stimulus in the absence of contraction-induced metabolite production that closely replicated the pattern of the mechanical stimulus present during dynamic contraction. We found that the increases in mean arterial blood pressure (freely perfused: 14 ± 1 and ligated: 23 ± 3 mmHg, P = 0.02) and renal sympathetic nerve activity were significantly greater during dynamic stretch of the ligated hindlimb compared with the increases during dynamic stretch of the freely perfused hindlimb. These findings suggest that the exaggerated mechanically sensitive component of the exercise pressor reflex found during dynamic muscle contraction in this rat model of simulated peripheral artery disease involves a chronic sensitizing effect of ligation on muscle mechanoreceptors and cannot be attributed solely to acute contraction-induced metabolite sensitization. NEW & NOTEWORTHY We found that the pressor and sympathetic nerve responses during dynamic stretch were exaggerated in rats with a ligated femoral artery (a model of peripheral artery disease). Our findings provide mechanistic insights into the exaggerated exercise pressor reflex in this model and may have important implications for peripheral artery disease patients.

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Genetic Variation in Blood Pressure and Lifetime Risk of Peripheral Artery Disease: A Mendelian Randomization Study

10.1101/2020.08.23.20180240 ◽

2020 ◽

Author(s):

Michael G Levin ◽

Derek Klarin ◽

Venexia M Walker ◽

Dipender Gill ◽

Julie Lynch ◽

...

Keyword(s):

Blood Pressure ◽

Calcium Channel ◽

Peripheral Artery Disease ◽

Genetic Correlations ◽

Channel Blockers ◽

Peripheral Artery ◽

Antihypertensive Medications ◽

Increased Risk ◽

Genes Encoding ◽

Artery Disease

Aims: We aimed to estimate the effect of blood pressure and blood pressure lowering medications (via genetic proxies) on peripheral artery disease. Methods and Results: GWAS summary statistics were obtained for BP (International Consortium for Blood Pressure + UK Biobank GWAS; N = up to 757,601 individuals), peripheral artery disease (PAD; VA Million Veteran Program; N = 24,009 cases, 150,983 controls), and coronary artery disease (CAD; CARDIoGRAMplusC4D 1000 Genomes; N = 60,801 cases, 123,504 controls). Genetic correlations between systolic BP (SBP), diastolic BP (DBP), pulse pressure (PP) and CAD and PAD were estimated using LD score regression. The strongest correlation was between SBP and CAD (rg = 0.36; p = 3.9 x 10-18). Causal effects were estimated by two-sample MR using a range of pleiotropy-robust methods. Increased SBP, DBP, and PP increased risk of both PAD (SBP OR 1.25 [1.19-1.31] per 10mmHg increase, p = 3 x 10-18; DBP OR 1.27 [1.17-1.39], p = 4 x 10-8; PP OR 1.51 [1.38-1.64], p = 1 x 10-20) and CAD (SBP OR 1.37 [1.29-1.45], p = 2 x 10-24; DBP OR 1.6 [1.45-1.76], p = 7 x 10-22; PP OR 1.56 [1.4-1.75], p = 1 x 10-15). The effects of SBP and DBP were greater for CAD than PAD (pdiff = 0.024 for SBP, pdiff = 4.9 x 10-4 for DBP). Increased liability to PAD increased PP (beta = 1.04 [0.62-1.45] mmHg per 1 unit increase in log-odds in liability to PAD, p = 1 x 10-6). MR was also used to estimate the effect of BP lowering through different classes of antihypertensive medications using genetic instruments containing BP-trait associated variants located within genes encoding protein targets of each medication. SBP lowering via calcium channel blocker-associated variants was protective of CAD (OR 0.38 per 10mmHg decrease in SBP; 95% CI 0.19-0.77; p = 0.007). Conclusions: Higher BP is likely to cause both PAD and CAD but may have a larger effect on CAD risk. BP-lowering through calcium-channel blockers (as proxied by genetic variants) decreased risk of CAD.

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Effect of a Home-Based Exercise Intervention of Wearable Technology and Telephone Coaching on Walking Performance in Peripheral Artery Disease

JAMA ◽

10.1001/jama.2018.3275 ◽

2018 ◽

Vol 319 (16) ◽

pp. 1665 ◽

Cited By ~ 54

Author(s):

Mary M. McDermott ◽

Bonnie Spring ◽

Jeffrey S. Berger ◽

Diane Treat-Jacobson ◽

Michael S. Conte ◽

...

Keyword(s):

Peripheral Artery Disease ◽

Exercise Intervention ◽

Wearable Technology ◽

Peripheral Artery ◽

Home Based ◽

Walking Performance ◽

Artery Disease ◽

Telephone Coaching

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Systemic and regional hemodynamic response to activation of the exercise pressor reflex in patients with peripheral artery disease

AJP Heart and Circulatory Physiology ◽

10.1152/ajpheart.00493.2019 ◽

2020 ◽

Vol 318 (4) ◽

pp. H916-H924 ◽

Cited By ~ 1

Author(s):

Danielle Jin-Kwang Kim ◽

Marcos Kuroki ◽

Jian Cui ◽

Zhaohui Gao ◽

J. Carter Luck ◽

...

Keyword(s):

Blood Pressure ◽

Blood Flow ◽

Peripheral Artery Disease ◽

Plantar Flexion ◽

Peripheral Artery ◽

Exercise Pressor Reflex ◽

Femoral Blood Flow ◽

Femoral Blood ◽

Pressor Reflex ◽

Artery Disease

Patients with peripheral artery disease (PAD) have an accentuated exercise pressor reflex (EPR) during exercise of the affected limb. The underlying hemodynamic changes responsible for this, and its effect on blood flow to the exercising extremity, are unclear. We tested the hypothesis that the exaggerated EPR in PAD is mediated by an increase in total peripheral resistance (TPR), which augments redistribution of blood flow to the exercising limb. Twelve patients with PAD and 12 age- and sex-matched subjects without PAD performed dynamic plantar flexion (PF) using the most symptomatic leg at progressive workloads of 2–12 kg (increased by 1 kg/min until onset of fatigue). We measured heart rate, beat-by-beat blood pressure, femoral blood flow velocity (FBV), and muscle oxygen saturation ([Formula: see text]) continuously during the exercise. Femoral blood flow (FBF) was calculated from FBV and baseline femoral artery diameter. Stroke volume (SV), cardiac output (CO), and TPR were derived from the blood pressure tracings. Mean arterial blood pressure and TPR were significantly augmented in PAD compared with control during PF. FBF increased during exercise to an equal extent in both groups. However, [Formula: see text] of the exercising limb remained significantly lower in PAD compared with control. We conclude that the exaggerated pressor response in PAD is mediated by an abnormal TPR response, which augments redistribution of blood flow to the exercising extremity, leading to an equal rise in FBF compared with controls. However, this increase in FBF is not sufficient to normalize the SmO2 response during exercise in patients with PAD. NEW & NOTEWORTHY In this study, peripheral artery disease (PAD) patients and healthy control subjects performed graded, dynamic plantar flexion exercise. Data from this study suggest that previously reported exaggerated exercise pressor reflex in patients with PAD is driven by greater vasoconstriction in nonexercising vascular territories which also results in a redistribution of blood flow to the exercising extremity. However, this rise in femoral blood flow does not fully correct the oxygen deficit due to changes in other mechanisms that require further investigation.

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