Ivabradine for Heart Rate Reduction During Exercise in Healthy Adults

NCT07717710 | Not Yet Recruiting Early Phase 1

• 1 other identifier: H25-03915
• Study Type: interventional
• Target: 20
• Locations: 1 country
• Sites: 1

Brief Summary

During exercise, working muscles require more oxygen. The heart meets this demand in two ways: by beating faster (heart rate) and by pumping more blood with each beat (stroke volume). Heart rate increases steadily with exercise intensity until exhaustion, but the amount of blood pumped with each beat tends to plateau at moderate intensities. Why the amount of blood pumped with each beat becomes limited before heart rate, however, is not well understood. Studying these mechanisms is difficult because most drugs that lower heart rate also affect how strongly the heart pumps, making it hard to separate the two effects. One medication that can help with this is ivabradine, which is used to treat people with heart disease who have high resting heart rates. It slows the heart rate without changing how strongly the heart pumps. This study will investigate whether ivabradine lowers heart rate during exercise in healthy younger and older adults, and whether a higher dose lowers heart rate more. The results will help us better understand how heart rate influences the heart's ability to supply oxygen to the body during exercise, and what limits the ability to exercise as people age. Participants will:

• Attend three visits at SportsCardiologyBC in Vancouver
• Complete a cycling exercise test at each visit to measure heart rate and how hard they can exercise
• Take ivabradine (a heart-rate-lowering medication) before the exercise test at Visits 2 and 3 (a lower dose at Visit 2 and a higher dose at Visit 3)
• Be monitored for side effects including slow heart rate, visual symptoms, and headache.

Conditions

Healthy Adult

Keywords

Heart rate regulation; Stroke volume; Cardiac output; Exercise; Exercise capacity

Outcome Measures

Primary Outcomes (1)

• Heart rate, peak

  Highest heart rate achieved during the cardiopulmonary exercise test.

  Within 30 minutes of exercise onset

Secondary Outcomes (5)

• Heart rate, resting

  Within 15 minutes prior to exercise onset

• Heart rate/work rate

  Within 30 minutes of exercise onset

• Incidence of visual symptoms

  Within 4 hours post-dose administration

• Incidence of headache

  Within 4 hours post-dose administration

• Incidence of bradycardia

  Within 4 hours post-dose administration

Study Arms (1)

Ivabradine

EXPERIMENTAL

All participants receive two single oral doses of ivabradine in a fixed sequence across separate experimental visits.

Drug: Ivabradine (single oral dose)

Interventions

Ivabradine (single oral dose) DRUG

A single oral dose of ivabradine is administered at each experimental visit, in a fixed order: 7.5 mg at Visit 2 (one 7.5 mg tablet), and 12.5 mg at Visit 3 (one 7.5 mg + one 5 mg tablet). Ivabradine is a selective hyperpolarization-activated cyclic nucleotide-gated transmembrane (HCN4) channel inhibitor that reduces heart rate without affecting myocardial contractility.

Ivabradine

Eligibility Criteria

• Age: 19 Years - 79 Years
• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• Healthy males and females aged 19-39 years, and 60-79 years
• Engaging in regular aerobic exercise (e.g., running, cycling, swimming, hiking, field, ice, or racquet sports) at least once per week

You may not qualify if:

• History of any cardiovascular condition, including hypertension
• Use of any chronic medication
• History of any respiratory condition, including asthma
• Smoking, including cannabis or vaping in the past year
• History of diabetes mellitus, cancer, hepatic, renal or any other chronic illness
• Seated blood pressure ≥130/90 or \<100/60 mmHg
• Body mass index \<20 or \>32 kg/m2
• Non-sinus rhythm or abnormalities on 12-lead electrocardiogram (ECG)
• Pregnant, breastfeeding, or women of childbearing potential not using appropriate contraception
• Current or recent (past year) participation in \>150 minutes per week of moderate-vigorous intensity exercise (to avoid endurance training-related bradycardia)
• Any condition that prevents vigorous exercise from being performed safely
• Seated resting heart rate \<60 beats per minute
• Prolonged QT interval (e.g., long QT syndrome)
• Sick sinus syndrome, sino-atrial block or third-degree atrio-ventricular block
• Use of strong cytochrome P450 (CYP3A4) inhibitors (e.g., nirmatrelvir and ritonavir, ketoconazole), which can increase ivabradine levels in the blood to potentially unsafe levels

Sponsors & Collaborators

• University of British Columbia: lead

Study Sites (1)

SportsCardiologyBC, UBC Hospital

Vancouver, British Columbia, V6T 2B5, Canada

Location

MeSH Terms

Conditions

Motor Activity

Interventions

Ivabradine

Condition Hierarchy (Ancestors)

Behavior

Intervention Hierarchy (Ancestors)

Benzazepines; Heterocyclic Compounds, 2-Ring; Heterocyclic Compounds, Fused-Ring; Heterocyclic Compounds

Central Study Contacts

Stephen P Wright, PhD

CONTACT

604-806-9292; stephen.wright@ubc.ca

Nathaniel Moulson, MD, MPH

CONTACT

604-822-9494; nathaniel.moulson2@vch.ca

Study Design

• Study Type: interventional
• Phase: early phase 1
• Allocation: NA
• Masking: NONE
• Purpose: BASIC SCIENCE
• Intervention Model: SINGLE GROUP
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Clinical Assistant Professor, Department of Medicine

Model Details: Non-randomized, unblinded, repeated measures design

Study Record Dates

• First Submitted: July 10, 2026
• First Posted: July 21, 2026
• Study Start: August 1, 2026
• Primary Completion (Estimated): December 1, 2026
• Study Completion (Estimated): December 1, 2026
• Last Updated: July 22, 2026

Record last verified: 2026-07

Data Sharing

• IPD Sharing: Will not share

Locations

CA (1)