Identifying Strategies to Alleviate Cardiovascular Stress in Coronary Patients During Heatwaves

NCT ID: NCT03832504

Last Updated: 2023-08-01

Basic Information

• Recruitment Status: COMPLETED
• Clinical Phase: NA
• Total Enrollment: 27 participants
• Study Classification: INTERVENTIONAL
• Study Start Date: 2019-02-18
• Study Completion Date: 2021-06-23

Brief Summary

The purpose of this study is to determine the optimal cooling strategies to alleviate cardiovascular strain of coronary artery disease individuals during a simulated North American and Australian heatwave.

Detailed Description

Globally, heatwaves are occurring more frequently, are of greater intensity and longer in duration. The devastating health impacts of extreme heat are increasingly recognized, particularly in vulnerable populations, such as adults with coronary artery disease (CAD). While the most effective cooling strategy during a heatwave is the use of air conditioning (AC), economical concerns can limit AC use among vulnerable populations. In addition, widespread AC use places a significant burden on the electrical grid, causing brown-outs and black-outs during periods of extreme heat.

Electric fans offer a cooling strategy with a 50-fold lower power requirement and cost compared to AC. However, the efficacy of fan use during heat waves remains contentious. The primary objective of this study is to identify the optimal cooling strategy to alleviate cardiovascular strain of CAD patients exposed to typical North American heatwave conditions (38°C with 60% relative humidity). The secondary objective is to identify the optimal cooling strategy to alleviate cardiovascular strain of CAD patients exposed to typical Australian heatwave conditions (46°C with 10% relative humidity).

Conditions

Coronary Artery Disease

Study Design

• Allocation Method: RANDOMIZED
• Intervention Model: CROSSOVER
• Primary Study Purpose: BASIC_SCIENCE
• Blinding Strategy: NONE

Study Groups

38°C and 60% RH + No intervention

The participant will enter an environmental chamber maintained at 38°C and 60% relative humidity. The participant will remain within the environmental chamber and will rest in a seated position for 3 hours.

Group Type: EXPERIMENTAL

No intervention

Intervention Type: OTHER

The participant will rest in a seated position.

38°C and 60% RH + Fan

The participant will enter an environmental chamber maintained at 38°C and 60% relative humidity. The participant will remain within the environmental chamber and will rest in a seated position for 3 hours.

Group Type: EXPERIMENTAL

Fan

Intervention Type: OTHER

A fan placed in front of the participant will provide an airflow of 4 m/s throughout the exposure.

38°C and 60% RH + Skin wetting

The participant will enter an environmental chamber maintained at 38°C and 60% relative humidity. The participant will remain within the environmental chamber and will rest in a seated position for 3 hours.

Group Type: EXPERIMENTAL

Skin Wetting

Intervention Type: OTHER

Tap water (\~18°C) will be applied every 5 minutes to the face, neck, upper and lower arms and upper and lower legs using a spray bottle.

38°C and 60% RH + Fan + Skin wetting

Tthe participant will enter an environmental chamber maintained at 38°C and 60% relative humidity. The participant will remain within the environmental chamber and will rest in a seated position for 3 hours.

Group Type: EXPERIMENTAL

Fan + Skin wetting

Intervention Type: OTHER

A fan placed in front of the participant will provide an airflow of 4 m/s throughout the exposure. In addition, tap water (\~18°C) will be applied every 5 minutes to the face, neck, upper and lower arms and upper and lower legs using a spray bottle.

46°C and 10% RH + No intervention

The participant will enter an environmental chamber maintained at 46°C and 10% relative humidity.

Group Type: EXPERIMENTAL

No intervention

Intervention Type: OTHER

The participant will rest in a seated position.

46°C and 10% RH + Skin wetting

The participant will enter an environmental chamber maintained at 46°C and 10% relative humidity. The participant will remain within the environmental chamber and will rest in a seated position for 3 hours.

Group Type: EXPERIMENTAL

Skin Wetting

Intervention Type: OTHER

Tap water (\~18°C) will be applied every 5 minutes to the face, neck, upper and lower arms and upper and lower legs using a spray bottle.

Interventions

No intervention

The participant will rest in a seated position.

Intervention Type: OTHER

Fan

A fan placed in front of the participant will provide an airflow of 4 m/s throughout the exposure.

Intervention Type: OTHER

Skin Wetting

Tap water (\~18°C) will be applied every 5 minutes to the face, neck, upper and lower arms and upper and lower legs using a spray bottle.

Intervention Type: OTHER

Fan + Skin wetting

A fan placed in front of the participant will provide an airflow of 4 m/s throughout the exposure. In addition, tap water (\~18°C) will be applied every 5 minutes to the face, neck, upper and lower arms and upper and lower legs using a spray bottle.

Intervention Type: OTHER

Eligibility Criteria

Inclusion Criteria

• History of angiographic coronary disease (≥70% arterial diameter narrowing of at least one major epicardial coronary artery) and/or prior coronary revascularization and/or documented prior acute coronary syndrome and/or stable angina and/or perfusion defect during exercise testing.
• No CAD-related hospitalisations or changes in cardiac medications or change in pattern of angina for at least 3 months prior to enrolment

Exclusion Criteria

• Body mass index ≥35 kg/m2.
• Currently undertaking estrogen therapy.
• Evidence of current fluid and electrolyte disorders, anemia, abnormal thyroid function, arrhythmias, diabetes, renal disease, liver disease, cerebrovascular disease, significant pulmonary disease, endocrine abnormalities, significant cognitive impairment, psychiatric disorder, substance abuse, degenerative neurological condition or any other medical condition deemed to pose risk during the proposed experiments.
• Uncontrolled hypertension (>180/110 mmHg).
• Recent (<3 months) coronary bypass surgery.
• Ejection fraction <40% and/or clinical evidence/history of heart failure.
• Significant valvular heart disease
• Resting ECG abnormalities interfering with observation of ST segment changes during testing.

• Minimum Eligible Age: 50 Years
• Maximum Eligible Age: 80 Years
• Eligible Sex: ALL
• Accepts Healthy Volunteers: No

Sponsors

National Health and Medical Research Council, Australia

OTHER

Sponsor Role: collaborator

Montreal Heart Institute

OTHER

Sponsor Role: lead

Responsible Party

Daniel Gagnon

Principal Investigator

Responsibility Role: PRINCIPAL_INVESTIGATOR

Locations

cardiovascular Prevention and rehabilitation Centre of the Montreal Heart Institute

Montreal, Quebec, Canada

Countries

Canada

Other Identifiers

ICM 2019-2425

Identifier Type: -

Identifier Source: org_study_id