An interventional study of Control/Sham Treatment and Heat Therapy (HT) in Peripheral Arterial Disease, sponsored by Indiana University. Completed at 1 site in United States. Per ClinicalTrials.gov, last updated 2022-08-30.
Sponsored by Indiana University · Not applicable, Interventional, and Treatment
The purpose of this study is to investigate whether exposure to heat therapy improves calf muscle oxygenation and enhances walking tolerance in patients with symptomatic Peripheral Arterial Disease (PAD).
Heat therapy (HT) is an emerging non-invasive approach that has been shown to enhance vascular function of the leg in old individuals. The objective of this study is to establish evidence to support the validity of HT in improving walking tolerance on PAD patents.
Subjects will complete baseline assessments for eligibility, including medical history and ankle-brachial measurement. Eligible participants will be asked to report to the laboratory on 4 different occasions. The purpose of visits 1 and 2 The central hypothesis of this study, based on preliminary data, is that exposure to HT will enhance the oxygenation of calf muscles during exercise and as a result, the onset of pain will be delayed and walking performance will be enhanced. is to familiarize the participants with the treadmill walking test and assess the test-retest reliability of maximal walking time determination. On visits 3 and 4 participants will receive either heat treatment or a control treatment for 80 min prior to undergoing a symptom-limited incremental test on the treadmill.
Exclusion Criteria:
Participants were fitted with liquid-circulating trousers. In the sham-treatment session, water at 33℃ was circulated through the trousers for 90 min using a water pump (HTP-1500, Adroit Medical, Louden, Tennessee, United States). At least 72 hrs after completion of the sham treatment session, participants returned to the laboratory and received the heat therapy (HT) treatment. In the HT session, water at 43℃ was circulated through the tube-lined trousers using a heated bath circulator (HT; Aqua Relief Systems, Akron, Ohio, United States) with the goal of increasing leg skin temperature to 37-38ºC.
Device: Control/Sham Treatment · Device: Heat Therapy (HT)
Participants were fitted with liquid-circulating trousers. In the HT session, water at 43℃ was circulated through the tube-lined trousers using a heated bath circulator (HT; Aqua Relief Systems, Akron, Ohio, United States) with the goal of increasing leg skin temperature to 37-38ºC. At least 72 hrs after completion of the sham treatment session, participants returned to the laboratory and received the sham treatment. In the sham-treatment session, water at 33℃ was circulated through the trousers for 90 min using a water pump (HTP-1500, Adroit Medical, Louden, Tennessee, United States).
Device: Control/Sham Treatment · Device: Heat Therapy (HT)
Water at 33ºC was circulated through water-circulating trousers.
Water at 42-43ºC was circulated through the water-circulating trousers.
Peak Walking Time
Exercise testing was performed in a motorized treadmill (Pro 27, Woodway, St. Paul, Minnesota, United States) following the Gardner-Skinner protocol, which consists of walking at a constant speed (2 mph) with a 2%-grade increase every 2 min (Gardner et al., 1991). Participants received standardized instructions and were asked to indicate when they first began to feel leg pain with a "thumbs up" signal (defined as COT), and then give a "thumbs down" signal when they could no longer continue with the test (defined as PWT).
Time frame: Immediately after exposure to a single session of heat therapy or sham treatment, up to ~20 min
Claudication Onset Time
Exercise testing was performed in a motorized treadmill (Pro 27, Woodway, St. Paul, Minnesota, United States) following the Gardner-Skinner protocol, which consists of walking at a constant speed (2 mph) with a 2%-grade increase every 2 min (Gardner et al., 1991). Participants received standardized instructions and were asked to indicate when they first began to feel leg pain with a "thumbs up" signal (defined as COT), and then give a "thumbs down" signal when they could no longer continue with the test (defined as PWT).
Time frame: The exercise test was performed immediately after exposure to a single session of either heat therapy or sham, up to ~20 min
Peak Systolic Blood Pressure
Blood pressure was measured in the left arm using a stethoscope and sphygmomanometer during exercise.
Time frame: The exercise test was performed immediately after exposure to a single session of either heat therapy or sham, up to ~20 min
Peak Diastolic Blood Pressure
Blood pressure was measured in the left arm using a stethoscope and sphygmomanometer prior and during exercise
Time frame: The exercise test was performed immediately after exposure to a single session of either heat therapy or sham, up to ~20 min
Peak Calf Tissue Saturation Index
The tissue saturation index (TSI%) of the most symptomatic leg was assessed with a commercially available NIRS system (Portamon, Artinis Medical Systems, The Netherlands).
Time frame: The exercise test was performed immediately after exposure to a single session of either heat therapy or sham, up to ~20 min
Post-exercise Plasma Endothelin-1 Concentration
Commercially available enzyme-linked immunosorbent assay kits were used to measure the plasma concentrations of ET-1 (DET100, Endothelin-1 Quantikine ELISA Kit, R\&D Systems, Minneapolis, MN, United States)
Time frame: The exercise test was performed immediately after exposure to a single session of either heat therapy or sham, up to ~20 min. Ten minutes following completion of the incremental treadmill test, blood samples were obtained for the assessment of serum ET-1
Participants were identified and contacted by the Indiana Clinical and Translational Science Institute Research Network (ResNet) research assistants. After interest in participation was established, patients were contacted directly by the investigators. Additional study participants were identified by physicians from the Division of Vascular Surgery at Methodist Hospital.
| Milestone | Sham, Then Heat Therapy | Heat Therapy, Then Sham |
|---|---|---|
| Started | 8 | 8 |
| Completed | 8 | 8 |
| Not completed | 0 | 0 |
| Milestone | Sham, Then Heat Therapy | Heat Therapy, Then Sham |
|---|---|---|
| Started | 8 | 8 |
| Completed | 8 | 8 |
| Not completed | 0 | 0 |
| Milestone | Sham, Then Heat Therapy | Heat Therapy, Then Sham |
|---|---|---|
| Started | 8 | 8 |
| Completed | 8 | 8 |
| Not completed | 0 | 0 |
Exercise testing was performed in a motorized treadmill (Pro 27, Woodway, St. Paul, Minnesota, United States) following the Gardner-Skinner protocol, which consists of walking at a constant speed (2 mph) with a 2%-grade increase every 2 min (Gardner et al., 1991). Participants received standardized instructions and were asked to indicate when they first began to feel leg pain with a "thumbs up" signal (defined as COT), and then give a "thumbs down" signal when they could no longer continue with the test (defined as PWT).
| seconds | Sham Treatment | Heat Therapy |
|---|---|---|
| Peak Walking Time | 955.6 ± 84.3 | 947.7 ± 88.1 |
Exercise testing was performed in a motorized treadmill (Pro 27, Woodway, St. Paul, Minnesota, United States) following the Gardner-Skinner protocol, which consists of walking at a constant speed (2 mph) with a 2%-grade increase every 2 min (Gardner et al., 1991). Participants received standardized instructions and were asked to indicate when they first began to feel leg pain with a "thumbs up" signal (defined as COT), and then give a "thumbs down" signal when they could no longer continue with the test (defined as PWT).
| Seconds | Sham Treatment | Heat Therapy |
|---|---|---|
| Claudication Onset Time | 452.6 ± 53.2 | 442.9 ± 65.1 |
Blood pressure was measured in the left arm using a stethoscope and sphygmomanometer during exercise.
| mmHg | Sham Treatment | Heat Therapy |
|---|---|---|
| Peak Systolic Blood Pressure | 193.3 ± 23.2 | 189.3 ± 31.0 |
Blood pressure was measured in the left arm using a stethoscope and sphygmomanometer prior and during exercise
| mmHg | Sham Treatment | Heat Therapy |
|---|---|---|
| Peak Diastolic Blood Pressure | 74.2 ± 9.7 | 73.5 ± 11.6 |
The tissue saturation index (TSI%) of the most symptomatic leg was assessed with a commercially available NIRS system (Portamon, Artinis Medical Systems, The Netherlands).
| % tissue saturation | Sham Treatment | Heat Therapy |
|---|---|---|
| Peak Calf Tissue Saturation Index | 43.9 ± 7.6 | 43.1 ± 8.2 |
Commercially available enzyme-linked immunosorbent assay kits were used to measure the plasma concentrations of ET-1 (DET100, Endothelin-1 Quantikine ELISA Kit, R\&D Systems, Minneapolis, MN, United States)
| pg/mL | Sham Treatment | Heat Therapy |
|---|---|---|
| Post-exercise Plasma Endothelin-1 Concentration | 2.0 ± 0.6 | 1.7 ± 0.5 |
Collected over Throughout the duration of the study (approximately 1 month).. Non-serious events are listed at a 0% frequency threshold.
| Group | Deaths | Serious | Other |
|---|---|---|---|
| Sham Treatment | 0/16 (0%) | 0/16 (0%) | 1/16 (6.3%) |
| Heat Therapy | 0/16 (0%) | 0/16 (0%) | 1/16 (6.3%) |
| Event | Sham Treatment | Heat Therapy |
|---|---|---|
| HypokalemiaBlood and lymphatic system disorders | 1/16 | 0/16 |
| HypotensionVascular disorders | 0/16 | 1/16 |
Nineteen participants were consented, but three were withdrawn before receiving an experimental treatment due to inability to safely and consistently perform the treadmill exercise test. Baseline clinical characteristics of the 16 participants that completed all study visits are presented.
| Age, Continuous(years) | All Study Participants |
|---|---|
| Mean | 65.7 ± 5.7 |
| Sex: Female, Male(Participants) | All Study Participants |
|---|---|
| Female | 2 |
| Male | 14 |
| Race (NIH/OMB)(Participants) | All Study Participants |
|---|---|
| American Indian or Alaska Native | 0 |
| Asian | 0 |
| Native Hawaiian or Other Pacific Islander | 0 |
| Black or African American | 4 |
| White | 12 |
| More than one race | 0 |
| Unknown or Not Reported | 0 |
| Region of Enrollment(Participants) | All Study Participants |
|---|---|
| United States | 16 |
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Indiana University