Hot Water Immersion After Myocardial Infarction (HOT-MI)

Hot Water Immersion in Rehabilitation After Myocardial Infarction (HOT-MI) - a Randomized Controlled Study

Myocardial infarction (MI) is a leading cause of death in developed countries, including Sweden. Standard treatment for patients after MI includes exercise-based cardiac rehabilitation which contributes to improved cardiovascular function and reduces the risk of hospital readmissions, new cardiovascular events and mortality. Thermotherapy may also have beneficial effects on cardiovascular disease by a reduction in inflammatory status and improved metabolism and vascular function. Given the well-documented effects of exercise training on cardiac rehabilitation and recent evidence that thermotherapy may improve cardiovascular function, we wish to investigate the effect of exercise combined with hot water immersion (HWI) in cardiac rehabilitation post-MI.

This is a single-centre, randomized controlled clinical trial in patients with recent MI. Our aim is to investigate whether exercise training combined with HWI improves inflammatory and metabolic status, cardiovascular function as well as psychological well-being, compared with exercise training alone. Patients will be randomized 1:1 to an 8 week intervention with exercise training 2 times per week followed by 15 minutes of hot water immersion, or to a control group with exercise training alone. The primary endpoint is changes in the inflammatory marker interleukin (IL-) 6 between groups at 8 weeks. Secondary endpoints include other biomarkers of inflammation, metabolism, effects on cardiovascular function and psychological benefits.

Secondary prevention after MI has improved during the last decades but readmissions and death following acute MI remain large health challenges. If HWI in addition to standard cardiac rehabilitation can lower inflammation more than standard therapy alone, and improve metabolic, cardiovascular and psychological status, it could be a cost-effective and safe complementary strategy for secondary prevention after MI, particularly for those with limited exercise capability.

Study Overview

• Status: Recruiting
• Conditions: Cardiac Rehabilitation; Cardiac Disease
• Intervention / Treatment: Other: Thermotherapy

• Study Type: Interventional
• Enrollment (Estimated): 30
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: Ole Fröbert, Professor; Phone Number: +460196025413; Email: ole.frobert@regionorebrolan.se
• Study Contact Backup: Name: Cecilia Bergh, PhD; Email: cecilia.bergh@regionorebrolan.se

Study Locations

• Sweden
  • Örebro, Sweden
    • Recruiting
    • Orebro University Hospital
    • Contact: Ole Fröbert, professor; Email: ole.frobert@regionorebrolan.se
    • Contact: Cecilia Bergh, PhD; Email: cecilia.bergh@oru.se

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years and older (Adult, Older Adult)
• Accepts Healthy Volunteers: No

Description

Inclusion criteria

• Patients with a diagnosis of ST-elevation myocardial infarction (STEMI) or non-STEMI
• Concomitant participation in standard care exercise-based cardiac rehabilitation
• Male or female patients ≥ 18 years
• Written informed consent

Exclusion criteria

• Regularly performing hot water immersion, sauna or other types of thermotherapy
• Not willing to perform hot water immersion regularly
• Febrile illness or acute, ongoing infection
• <18 years of age
• Inability to provide informed consent

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Double

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Hot water immersion; Patients allocated to hot water immersion will enter a bath and submerge down to the neck in warm water (40 degrees celsius) for 15 min.	Other: Thermotherapy; Hot baths directly after an exercise session
No Intervention: Control; Patients allocated to control group will sit down for a 15 min rest.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Concentrations of interleukin 6 (IL-6) in blood	Change in IL-6 between groups after 8 weeks of intervention	8 weeks

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Concentrations of other biomarkers of inflammation in blood	Change in IL -1b, IL-10, tumor necrosis factor (TNF)-a, High sensitivity C-reactive protein, heat shock protein-72 after 8 weeks of intervention	8 weeks
Concentrations of biomarkers of metabolism in blood	Heat shock factor (HSF)-1, High density lipoprotein, Low density lipoprotein, triglycerides, cholesterol, leptin and adiponectin, glucose, insulin	8 weeks
Change in percent in endothelial flow-mediated dilatation (FMD)	Change after 8 weeks of intervention	8 weeks
Change in sympathetic/parasympathetic activity	Change in heart rate variability after 8 weeks of intervention	8 weeks
Change in score of participants´ subjectively reported psychological well-being	Measured with the Questionnaire Clinical Outcomes in Routine Evaluation (Core-GP), change after 8 weeks of intervention	8 weeks
Change in diastolic and systolic blood pressure (mm(Hg)	Change after 8 weeks of intervention	8 weeks

Other Outcome Measures

Outcome Measure	Time Frame
Troponin I	8 weeks

Collaborators and Investigators

• Sponsor: Region Örebro County

Study record dates

Study Major Dates

• Study Start (Actual): October 26, 2023
• Primary Completion (Estimated): December 31, 2024
• Study Completion (Estimated): December 31, 2025

Study Registration Dates

• First Submitted: February 2, 2023
• First Submitted That Met QC Criteria: February 2, 2023
• First Posted (Actual): February 13, 2023

Study Record Updates

• Last Update Posted (Actual): November 1, 2023
• Last Update Submitted That Met QC Criteria: October 30, 2023
• Last Verified: October 1, 2023

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Ischemia; Pathologic Processes; Necrosis; Myocardial Ischemia; Cardiovascular Diseases; Vascular Diseases; Myocardial Infarction; Infarction; Heart Diseases
• Other Study ID Numbers: 279938

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No