Potential Biological and Physiological Determinants for Exercice in Patients With Polycythemia Vera (ACTIVAQ)

Civil Hospices of Lyon

Status: Not yet enrolling

Conditions: Polycythemia Vera (PV); Polycythemia

Treatments: Biological: Research samples blood viscosity and viscoelasticity:

Study type: Interventional

Funder types: Other

Identifiers

NCT07341048

2025-A01032-47 (Other Identifier)

69HCL25_0364

Details and patient eligibility

About

Polycythemia vera (PV) is a rare haematological disorder characterized by an excessive production of red blood cells, associated with the somatic JAK2 V617F mutation. Clinical manifestations are varied and often include exercise intolerance but the underlying mechanisms remain poorly understood.

Physical activity is recommended in the management of chronic diseases, but it must be tailored to the physiological profile of the patient. A cardiopulmonary exercise test (CPET) is essential to ensure safety, detect possible contraindications, and assess maximal oxygen uptake (VO₂max), a key indicator of aerobic performance.

This prospective, experimental, non-randomized study will include patients with PV followed at Lyon Sud University Hospital and for which a CPET is scheduled in their routine clinical follow-up. The primary objective is to compare VO₂max between two groups of patients: moderate (<10%) versus marked (≥10%) extent of blood viscosity increase after the completion of the CPET. The main hypothesis is that a significant increase in blood viscosity during exercise (≥10%) is a major limiting factor in oxygen transport and leads to a reduced VO₂max, reflecting impaired exercise tolerance.

Secondary analyses will focus on hemorheological parameters, tissue oxygenation, and cardiorespiratory and metabolic responses. The study aims to better understand the biological and physiological determinants of exercise intolerance in this population.

Enrollment: 54 estimated patients

Sex: All

Ages: 18 to 70 years old

Volunteers: No Healthy Volunteers

Inclusion criteria

• Patient aged at least 18 years and under 70.
• Patient followed for a diagnosis of Polycytemia vera (confirmed JAK2 V617F mutation) and who were prescribed a CPET because of their wish to resume regular physical activity.
• Patient affiliated with or benefiting from a social security scheme.

Exclusion criteria

• Any known history of heart disease or chronic respiratory illness likely to affect VO₂max independently of Polycytemia vera (e.g., asthma), according to the investigator's judgment.
• Any known history of major thromboembolic complication, according to the investigator's judgment.
• Body mass index (BMI) greater than 35, according to the investigator's judgment.
• Participation in another interventional research protocol that may interfere with the present study, according to the investigator's judgment.
• Adult subject under legal protection measures (guardianship, curatorship).
• Subject currently receiving psychiatric care.
• Subject deprived of liberty by judicial or administrative decision.

Trial design

Primary purpose: Basic Science

Allocation: N/A

Interventional model: Single Group Assignment

Masking: None (Open label)

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54 participants in 1 patient group

Polycythemia vera

Experimental group

Description:

Patients diagnosed with polycythemia vera, with confirmed presence of the JAK2 V617F mutation, who wish to resume regular daily physical activity and have been prescribed an exercise test for this purpose as part of their follow-up at Lyon Sud Hospital

Treatment:

Biological: Research samples blood viscosity and viscoelasticity: