The Right Heart in PAH

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The size, shape, and function of the right heart are key signals of PAH disease status. As a result, its near-normalization is a critical consideration in improving patient outcomes.1-8 Echo offers a noninvasive way to assess the hemodynamic burden on the right heart at diagnosis and throughout a patient’s disease.4

Changes in the right heart are leading indicators of disease status

Although PAH is a lung disease, the tight coupling between the pulmonary arteries and the right heart means that PAH-associated vascular remodeling can lead to right-sided heart failure—the most common cause of death in patients with PAH.9,10 At diagnosis, evaluating right heart structure and function is critical to assess PAH disease severity.

Because PAH is a progressive disease, regular follow-up assessment of the right heart is required. Although clinical parameters such as 6MWD and FC are commonly used to monitor patients with PAH, they are lagging indicators of disease progression. Changes in the right heart precede changes in functional capacity, and detrimental changes in the right heart can happen in as few as 12 weeks. Right heart changes can also be one of the first signs that a treatment plan is working, or if changes may be needed.3-6

Timeline illustrating a proposed sequence of disease progression in PAH from earliest to latest
Adapted from Milks MW, et al. J Heart Lung Transplant. 2021;40(3):172-182.
Image Description

Disease progression over time:

  • Changes in the right heart
  • Change in NT-proBNP
  • Change in 6MWD
  • Change in weight
  • Change in FC
  • Hospitalization

“If we wait for [symptoms] to worsen before we adjust [a patient’s] treatment regimen, we may miss an opportunity to improve their functional impairment.”

–Dr. Anjali Vaidya

Co-Director, Pulmonary Hypertension, Right Heart Failure & CTEPH Program

Temple University

Near-normalization of the right heart is a key treatment goal

Although it may not be possible for many patients with PAH to achieve normal right heart pressures, near-normalization remains an important goal of treatment. Near-normalization of the right heart is associated with improved risk status and 5-year survival for patients with PAH.4-8,11 Frequent monitoring of the right heart’s structure and function can help inform treatment decisions.4 Conversely, waiting for symptoms of right-sided heart failure before adjusting a patient’s treatment regimen represents a lost opportunity to minimize functional impairment.2,3

“The right heart, as I say, is the key to the whole game. And if we get near-normalization of the right heart, then we are in a really good spot to give the patients the best possible outcomes that they can have.”

–Dr. John Ryan

Director, Pulmonary Hypertension Center

University of Utah

The Echo in PAH: Hear from the experts

In The Echo in PAH: State of the Art in Right Heart Monitoring broadcast, Drs. Anjali Vaidya and John Ryan provided their expert perspectives on how to use Echo to help evaluate disease status and inform PAH management approaches.

View short excerpts from The Echo in PAH
Click to expand transcript

[Video title: The Echo in PAH: Routine Echos Detect Changes]

[On-screen text: John Ryan, MD, MB, BCH, BAO; Anjali Vaidya, MD, FACC, FASE, FACP; Excerpt from The Echo in PAH: State of the Art in Right Heart Monitoring]

[On-screen text: John Ryan, MD, MB, BCH, BAO, Associate Professor, Division of Cardiovascular Medicine, University of Utah; Director, Pulmonary Hypertension Center, University of Utah, Salt Lake City, Utah]

Dr. John Ryan: The changes in the right heart are the first things that will occur, and we don't necessarily have good ways of evaluating that, other than echocardiogram. Even these changes in the right heart will precede changes in N-terminal proBNP. A lot of us depend on N-terminal proBNP in clinic, following patients longitudinally. Then you'll get a change in 6-minute walk, then you'll get a change in weight, then you'll get a change in Functional Class, and then you'll get hospitalization.

So, we don't want to progress to change in Functional Class or change in hospitalization. We want to capture this early. So, performing a routine Echo may help catch patients whose pulmonary arterial hypertension is progressing before the symptoms are evident.

[On-screen text: Excerpt from The Echo in PAH: State of the Art in Right Heart Monitoring; View the entire program at www.RightHeartInPAH.com]

[On-screen text: PAH Initiative; Sponsored by United Therapeutics; PAHinitiative.com/hcp; © 2023 United Therapeutics Corporation. All rights reserved. US-DS-1105]

Routine Echos Detect Changes (1 minute)

Watch as Dr. John Ryan discusses how frequent Echo assessment can lead to earlier detection of changes due to PAH.

View the full program on YouTube: State of the Art in Right Heart Monitoring.

Routine Echos Detect Changes video thumbnail

Routine Echos Detect Changes
(1 minute)

Frequent Echos Improve Gestalt video thumbnail

Frequent Echos Improve Gestalt
(1 minute 30 seconds)

The Echo Doesn’t Lie video thumbnail

The Echo Doesn’t Lie
(1 minute)

Near-Normalization Improves Prognosis video thumbnail

Near-Normalization Improves Prognosis
(1 minute)

Performing routine Echos may help catch PAH progression before symptoms worsen

Echos are recommended as often as every 3 to 6 months in patients with PAH

Echo provides insight into disease progression before clinical symptoms worsen.5 In addition, it can further stratify patients to give important prognostic information and determine an appropriate treatment plan, particularly for those in the intermediate-risk group (eg, those with mild or moderate PAH).8

As a result, treatment guidelines recommend frequent Echos to monitor disease status in PAH. The 2022 ESC/ERS Guidelines state that Echo is indicated every 3 to 6 months after changes in therapy and in the case of clinical worsening. In addition, Echo may be considered as often as every 3 to 6 months even in patients who are stable.11

How to conduct a comprehensive Echo of the right heart

An Echo should include a multiparameter assessment11:

  • Estimating the systolic pulmonary arterial pressure and other signs associated with PAH
  • Measurements of RV size and function
  • Measurements of the size of the RA
  • Relative proportions of the RV to the LV

For additional information on Echo parameters that are important for assessing the right heart in PAH, download the Echo Reference Guide

Table showing views that can be captured from Echo assessments

“[Echo] monitoring is really critical [in PAH], and it should be done with high frequency to identify early recognition of a patient's clinical status that's declining.”

–Dr. Anjali Vaidya

Co-Director, Pulmonary Hypertension, Right Heart Failure & CTEPH Program

Temple University

Find out more about how right heart parameters inform risk status

Integrate Risk Calculation
6MWD=6-minute walk distance; Echo=echocardiogram; ESC/ERS=European Society of Cardiology/European Respiratory Society; FC=Functional Class; LV=left ventricle; NT-proBNP=N-terminal pro-brain natriuretic peptide; PAH=pulmonary arterial hypertension; RA=right atrium; RHC=right heart catheterization; RV=right ventricle.References: 1. Simonneau G, et al. Am J Respir Crit Care Med. 2002;165(6):800-804. 2. Adamson PB. Curr Heart Fail Rep. 2009;6(4):287-292. 3. Milks MW, et al. J Heart Lung Transplant. 2021;40(3):172-182. 4. Miotti C, et al. J Clin Med. 2021;10(4):619. 5. Sahay S, et al. PLoS One. 2020;15(11):e0241504. 6. Badagliacca R, et al. Am J Respir Crit Care Med. 2021;203(4):484-492. 7. Kia DS, et al. Front Physiol. 2021;12:641310. 8. Badagliacca R, et al. J Heart Lung Transplant. 2018;37:195-205. 9. Champion HC, et al. Circulation. 2009;120(11):992-1007. 10. Tonelli AR, et al. Am J Respir Crit Care Med. 2013;188(3):365-369. 11. Humbert M, et al. Eur Heart J. 2022;43(38):3618-3731.