Clinical trial NCT06961929: IEEM-Heat and Heart Failure
Official title: IEEM-Heat and Heart Failure
Study type: INTERVENTIONAL
Overall status: NOT_YET_RECRUITING
Phase: NA
Conditions: Heart Failure
Hyperthermia
Keywords: heat wave
cardiovascular
cooling strategies
myocardial perfusion
Lead sponsor: University of Texas Southwestern Medical Center
Sponsor class: OTHER
Collaborators: name: National Institute on Aging (NIA)
First posted: 2025-05-08
Enrollment: 88
Sex: ALL
Minimum age (years): 18
Standard ages: ADULT
OLDER_ADULT
Accepts healthy volunteers: yes
Allocation: RANDOMIZED
Intervention model: CROSSOVER
Primary purpose: BASIC_SCIENCE

Brief summary: We will test the hypothesis that increasing skin wetness, and thus evaporative cooling, will attenuate the increase in core body temperature and accompanying cardiac stress during heat wave conditions in individuals with congestive heart failure. Secondly, we propose that fan use alone may be possibly detrimental (very hot and dry) depending on the environmental conditions. To accomplish these objectives, individuals with congestive heart failure and otherwise healthy control individuals will be exposed to the simulated heat wave condition (very hot and dry) with the following cooling modalities: A) control trial (no fan or skin wetting), B) skin wetting only trial, and C) fan only trial in a randomized crossover fashion. Thermoregulatory and cardiovascular responses will be evaluated throughout these simulated heat wave exposures.

Primary outcomes variables will be skin and core temperatures, while secondary variables will include measures of cardiovascular stress, myocardial perfusion, heart rate, and echo-based measures of cardiac function.


Eligibility criteria: Inclusion Criteria for healthy control participants:

* Participants must be free of any significant underlying medical problems based upon a detailed medical history and physical exam, and normal resting electrocardiogram. Participants must be 18+ years. However, since they will be age-matched to individuals with CHF, we anticipate most of the participants will be 45+ years old.

Exclusion Criteria for healthy control participants:

* Known heart disease; other chronic medical conditions requiring regular medical therapy including cancer, diabetes, neurological diseases, and uncontrolled hypertension, lung disease, etc.; as well as serious abnormalities detected on routine screening. Participants with a body mass index ≥ 35 kg/m2 will be excluded. Current smokers, as well as individuals who regularly smoked within the past 9 months, will be excluded. Subjects who cannot be age and gender matched to an individual in the heart failure group will be excluded.

Inclusion Criteria for Participants with CHF:

- The participant must have a diagnosis of congestive heart failure (e.g., heart failure with reduced ejection fraction), with the severity categorized as New York Heart Association (NYHA) class II or III. Participants must be 18+ years, though we anticipate that most participants with heart failure will be 45+ years old.

Exclusion Criteria for Participants with CHF:

-Patients who do not have confirmed diagnosis of NYHA class II or III heart failure will be excluded from the clinical group. Potential participants with cancer, diabetes, neurological disease, lung disease, and/or uncontrolled hypertension will be excluded. Potential participants with a left bundle branch block on ECG will be excluded, as well as those with an ejection fraction \>40%. Patients on anticoagulant therapy will also be excluded. Participants with a body mass index ≥ 35 kg/m2 will be excluded. Current smokers, as well as individuals who regularly smoked within the past 9 months, will be excluded. Further exclusions will include severe valvular or congenital heart disease, acute myocarditis, NYHA Class IV heart failure, and/or manifest/provocable ischemic heart disease.

Primary outcomes:
measure: Change in Core Body Temperature in Fan Trial
timeFrame: Prior to and after each simulated heat wave exposure (approximately 180 minutes.)
measure: Change in Core Body Temperature in Skin-Wetting Trial
timeFrame: Prior to and after each simulated heat wave exposure (approximately 180 minutes.)
measure: Change in Core Body Temperature in Control Trial
timeFrame: Prior to and after each simulated heat wave exposure (approximately 180 minutes.)
measure: Change in Skin Temperature in Fan Trial
timeFrame: Prior to and after each simulated heat wave exposure (approximately 180 minutes.)
measure: Change in Skin Temperature in Skin-Wetting Trial
timeFrame: Prior to and after each simulated heat wave exposure (approximately 180 minutes.)
measure: Change in Skin Temperature in Control Trial
timeFrame: Prior to and after each simulated heat wave exposure (approximately 180 minutes.)
Secondary outcomes:
measure: Change in Heart Rate in Fan Trial
timeFrame: Prior to and after each simulated heat wave exposure (approximately 180 minutes.)
measure: Change in Heart Rate in Skin-Wetting Trial
timeFrame: Prior to and after each simulated heat wave exposure (approximately 180 minutes.)
measure: Change in Heart Rate in Control Trial
timeFrame: Prior to and after each simulated heat wave exposure (approximately 180 minutes.)
measure: Rate Pressure Product in Fan Trial
timeFrame: At the end of each heat wave exposure. Approximately 180 minutes after the start of the heat wave simulation.
measure: Rate Pressure Product in Skin-Wetting Trial
timeFrame: At the end of each heat wave exposure. Approximately 180 minutes after the start of the heat wave simulation.
measure: Rate Pressure Product in Control Trial
timeFrame: At the end of each heat wave exposure. Approximately 180 minutes after the start of the heat wave simulation.
measure: Change in Cardiac Output in Fan Trial
timeFrame: Prior to and after each simulated heat wave exposure (approximately 180 minutes.)
measure: Change in Cardiac Output in Skin-Wetting Trial
timeFrame: Prior to and after each simulated heat wave exposure (approximately 180 minutes.)
measure: Cardiac Output in Control Trial
timeFrame: Prior to and after each simulated heat wave exposure (approximately 180 minutes.)
Other outcomes:
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