PV Loop and Pulmonary Hypertension

Recruiting

• Conditions: Pulmonary Vascular Resistance Abnormality
• Interventions: Procedure: Measuring VA Coupling

• Registration Number: NCT05484596
• Lead Sponsor: Hythem Nawaytou

Brief Summary

The right ventricular (RV) systolic function is a key determinant of outcome in patients with pulmonary hypertension and elevated pulmonary vascular resistance. As the pulmonary artery pressure and vascular resistance increase (i.e. RV afterload) in these patients, so does the right ventricular contractility in an attempt to maintain cardiac output. This is response of a ventricle to its afterload is termed ventriculo-arterial (VA) coupling. However, there is a limit to this increase in contractility after which VA uncoupling occurs ultimately leading to decrease cardiac output and right ventricular failure. The accepted gold standard for measurement of VA coupling is the ratio of the end systolic ventricular elastance (Ees) to the end systolic arterial elastance (Ea) measured invasively via high fidelity conductance catheters during cardiac catheterization. In this study, the aim is to devise a non-invasive scoring system that can identify VA uncoupling in patients with elevated pulmonary vascular resistance using echocardiography, cardiac MRI, cardiopulmonary exercise testing and brain natriuretic peptide levels. The hypothesis is that a group of morphologic and functional variables obtained noninvasively can differentiate an RV with VA coupling from that with VA uncoupling.

Detailed Description

Not available

Study Timeline

• Study Start: 2020-04-27
• Study First Submitted: 2022-07-08
• Study First Submitted QC: 2022-07-29
• Study First Posted: 2022-08-02
• Status Verified: 2023-09
• Last Update Submitted: 2023-09-22
• Last Update Posted: 2023-09-26
• Primary Completion: 2025-04-30
• Study Completion: 2025-04-30

Recruitment & Eligibility

• Status: RECRUITING
• Sex: All
• Target Recruitment: 65

Inclusion Criteria

• Children 1-21 years of age
• Patients referred for cardiac catheterization for hemodynamic evaluation due to concern for pulmonary hypertension
• Structurally normal heart

Exclusion Criteria

• Pulmonary hypertension secondary to pulmonary venous hypertension defined as pulmonary capillary wedge pressure of more than or equal to 15mmHg
• Pulmonary hypertension secondary to mixed pulmonary arterial and venous hypertension
• Patient will be excluded from performing an MRI if they have:

claustrophobia, metal implants or allergy to contrast

• Patients will be excluded from performing a cardiopulmonary exercise test (CPET) if they are: 1) less than 8 years or 2) unable to follow instructions to run on a treadmill.

Study & Design

• Study Type: OBSERVATIONAL
• Study Design: Not specified

Arm && Interventions

Group	Intervention	Description
Observational Group	Measuring VA Coupling	Subjects will undergo clinically indicated investigations and tests. The research part of the study is measuring the VA coupling using high fidelity catheters. That is expected to increase the duration of the cardiac catheterization for 30 minutes.

Primary Outcome Measures

Name	Time	Method
Identify echocardiographic measurements of right ventricular systolic function and pulmonary blood flow and their cutoff values contemporaneous that can identify VA uncoupling	within one week of measurement of ventriculo-arterial coupling ratio during cardiac catheterization	Yes/No result: Can echocardiographic measurements allow non-invasive identification of VA uncoupling (defined as Ees/Ea \<0.805). Three ratios: tricuspid annular plane systolic excursion to the pulmonary artery acceleration time, right ventricular free wall strain to the pulmonary artery acceleration time and, right ventricular fractional area change to the pulmonary artery acceleration time.
Identify cMRI measurements of right ventricular systolic function and pulmonary blood flow and their cutoff values contemporaneous that can identify VA uncoupling.	within one week of measurement of ventriculo-arterial coupling ratio during cardiac catheterization	Yes/No result: Can cMRI measurements allow non-invasive identification of VA uncoupling (defined as Ees/Ea \<0.805). Two ratios: right ventricular ejection fraction to right ventricular end systolic volume and right ventricular ejection fraction to pulmonary artery acceleration time (by echocardiography).
Identify 6-minute walk distance cutoff that can identify VA uncoupling	within one week of measurement of ventriculo-arterial coupling ratio during cardiac catheterization	Yes/No: Can 6-minute walk distance identify VA uncoupling (defined as Ees/Es\<0.805)
Identify brain natriuretic peptide cutoff value that can identify VA uncoupling	within one week of measurement of ventriculo-arterial coupling ratio during cardiac catheterization	Yes/No: Can brain natriuretic peptide identify VA uncoupling (defined as Ees/Es\<0.805)

Trial Locations

Locations (2)

Pediatric Pulmonary Hypertension Program; 🇺🇸 San Francisco, California, United States

University of Minnesota; 🇺🇸 Minneapolis, Minnesota, United States