Aging, Coronary Artery Disease, Healthy, Hot Weather; Adverse Effect
Conditions
Keywords
Heat, PET imaging, Myocardial blood flow
Brief summary
The purpose of this study is to determine the increase in myocardial blood flow during heat exposure and how this response is affected by age and coronary artery disease.
Detailed description
As a result of climate change, heat waves are more frequent and of longer duration. These heat waves are associated with a higher risk of hospitalization and mortality in vulnerable populations such as people with cardiovascular disease or cardiovascular risk factors. It has been hypothesized that this observation may be explained by the cardiovascular demands imposed by heat exposure. Heat exposure requires increased cardiac work that may place individuals with cardiovascular disease at risk of ischemic events if the metabolic demand is not compensated by adequate blood supply. However, the extent to which cardiac work increases during heat exposure remains unknown. The aim of this study is to test the hypothesis that heat exposure increases myocardial blood flow and that this increase is affected by age and coronary artery disease.
Interventions
OTHERHeat exposure
Participants will be exposed to heat exposure via a water-perfused suit to increase internal body temperature by 1.5 degrees Celsius.
Sponsors
Montreal Heart Institute
Study design
Allocation
NA
Intervention model
SINGLE_GROUP
Primary purpose
BASIC_SCIENCE
Masking
NONE
Eligibility
Sex/Gender
ALL
Age
18 Years to 80 Years
Healthy volunteers
Yes
Inclusion criteria
for Healthy Participants: * Age between 18-40 years or 60-80 years * Non-smoker (≥1 year) * Non-diabetic * Normal kidney function * Body Mass Index \<30 kg/m2 * Resting blood pressure \<140/\<90 mmHg * Resting heart rate \<100 bpm Inclusion Criteria for Participants with Coronary Artery Disease: * Age between 60-80 years old * 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 perfusion defect during stress testing * Stable medications (≥4 weeks) prior to enrollment
Exclusion criteria
for Healthy Participants: * Diagnosis of heart, vascular, respiratory, neurological or metabolic disease and/or a prescription of medication for the treatment of these diseases * Pregnancy or lactation * Dyslipidemia not controlled by medication
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Global myocardial blood flow | Change from baseline to an increase in internal body temperature of 1.5 degrees Celsius, estimated average = 90 minutes | Measured by PET imaging with 82rubidium |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Myocardial blood flow distribution | Change from baseline to an increase in internal body temperature of 1.5 degrees Celsius, estimated average = 90 minutes | Measured by PET imaging with 82rubidium |
| Heart rate | Change from baseline to an increase in internal body temperature of 1.5 degrees Celsius, estimated average = 90 minutes | Measured by electrocardiogram |
| Systolic and diastolic blood pressure | Change from baseline to an increase in internal body temperature of 1.5 degrees Celsius, estimated average = 90 minutes | Measured by automated auscultation of the brachial artery |
| Body weight | Measured before and after heat exposure, estimated average = 120 minutes | Measured with a scale |
Countries
Canada
Outcome results
None listed