Characterization of Myocardial Blood Flow During Heat Exposure

Not Applicable

Completed

• Conditions: Healthy; Coronary Artery Disease; Hot Weather; Adverse Effect; Aging
• Interventions: Other: Heat exposure

• Registration Number: NCT04549974
• Lead Sponsor: Montreal Heart Institute

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.

Study Timeline

• Study Start: 2020-08-25
• Study First Submitted: 2020-08-25
• Study First Submitted QC: 2020-09-14
• Study First Posted: 2020-09-16
• Primary Completion: 2023-03-31
• Study Completion: 2023-03-31
• Status Verified: 2023-05
• Last Update Submitted: 2023-05-05
• Last Update Posted: 2023-05-08

Recruitment & Eligibility

• Status: COMPLETED
• Sex: All
• Target Recruitment: 80

Inclusion Criteria

Not provided

Exclusion Criteria

Not provided

Study & Design

• Study Type: INTERVENTIONAL
• Study Design: SINGLE_GROUP

Arm && Interventions

Group	Intervention	Description
Passive heat exposure	Heat exposure	-

Primary Outcome Measures

Name	Time	Method
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 Outcome Measures

Name	Time	Method
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
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
Heart rate	Change from baseline to an increase in internal body temperature of 1.5 degrees Celsius, estimated average = 90 minutes	Measured by electrocardiogram
Body weight	Measured before and after heat exposure, estimated average = 120 minutes	Measured with a scale

Trial Locations

Locations (1)

Montreal Heart Institute; 🇨🇦 Montréal, Quebec, Canada