Identifying Strategies to Alleviate Cardiovascular Stress in Coronary Patients During Heatwaves

Not Applicable

Completed

• Conditions: Coronary Artery Disease
• Interventions: Other: No intervention; Other: Fan; Other: Skin Wetting; Other: Fan + Skin wetting

• Registration Number: NCT03832504
• Lead Sponsor: Montreal Heart Institute

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).

Study Timeline

• Study First Submitted: 2019-01-21
• Study First Submitted QC: 2019-02-04
• Study First Posted: 2019-02-06
• Study Start: 2019-02-18
• Primary Completion: 2021-06-23
• Study Completion: 2021-06-23
• Status Verified: 2023-07
• Last Update Submitted: 2023-07-31
• Last Update Posted: 2023-08-01

Recruitment & Eligibility

• Status: COMPLETED
• Sex: All
• Target Recruitment: 27

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.

Study & Design

• Study Type: INTERVENTIONAL
• Study Design: CROSSOVER

Arm && Interventions

Group	Intervention	Description
38°C and 60% RH + No intervention	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.
38°C and 60% RH + Fan	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.
46°C and 10% RH + No intervention	No intervention	The participant will enter an environmental chamber maintained at 46°C and 10% relative humidity.
38°C and 60% RH + Skin wetting	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.
46°C and 10% RH + Skin wetting	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.
38°C and 60% RH + Fan + Skin wetting	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.

Primary Outcome Measures

Name	Time	Method
Rate pressure product	Change from baseline to the end of the 3 hour exposure	Rate pressure product, in beats per minute per mmHg

Secondary Outcome Measures

Name	Time	Method
Body core temperature	Change from baseline to the end of the 3 hour exposure	In degrees Celcius

Trial Locations

Locations (1)

cardiovascular Prevention and rehabilitation Centre of the Montreal Heart Institute; 🇨🇦 Montréal, Quebec, Canada