Clinical trial NCT03832504: Identifying Strategies to Alleviate Cardiovascular Stress in Coronary Patients During Heatwaves
Official title: Identifying Optimal Cooling Strategies for Coronary Artery Disease Patients During Heatwaves
Study type: INTERVENTIONAL
Overall status: COMPLETED
Phase: NA
Conditions: Coronary Artery Disease
Lead sponsor: Montreal Heart Institute
Sponsor class: OTHER
Collaborators: name: National Health and Medical Research Council, Australia
First posted: 2019-02-06
Enrollment: 27
Sex: ALL
Minimum age (years): 50
Maximum age (years): 80
Standard ages: ADULT
OLDER_ADULT
Accepts healthy volunteers: no
Allocation: RANDOMIZED
Intervention model: CROSSOVER
Primary purpose: BASIC_SCIENCE

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).

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.

Primary outcomes:
measure: Rate pressure product
timeFrame: Change from baseline to the end of the 3 hour exposure
Secondary outcomes:
measure: Body core temperature
timeFrame: Change from baseline to the end of the 3 hour exposure
Other outcomes:
measure: Skin temperature
timeFrame: Change from baseline to the end of the 3 hour exposure
measure: Sweat loss
timeFrame: Change from baseline to the end of the 3 hour exposure
measure: Local sweat rate
timeFrame: Measured continously during the 3 hour exposure
measure: Skin blood flow
timeFrame: Measured continously during the 3 hour exposure.
Locations:
city: Montréal
country: Canada
facility: cardiovascular Prevention and rehabilitation Centre of the Montreal Heart Institute
state: Quebec
Study officials:
References: