News Release

Title
Mild elevation of pulmonary vascular resistance predicts mortality regardless ofmean pulmonary artery pressure in mild interstitial lung disease
Key Points⚫

Pulmonary hypertension (PH) is defined by elevated mean pulmonary
arterial pressure (MPAP), and elevated pulmonary vascular resistance(PVR) reflects pulmonary vascular abnormalities. PH is an importantcomplicationthat

negatively

affects

mortality

inpatients

withinterstitial lung disease (ILD).
⚫

In our analyses of newly diagnosed ILD patients, mild elevation of PVR(> 2 Wood Units) was associated with a higher mortality rate, even in
those with MPAP ≤ 20 mm Hg.

Summary
Pulmonary hypertension (PH) is defined by elevated mean pulmonary arterialpressure (MPAP), and elevated pulmonary vascular resistance (PVR) reflects
pulmonary vascular abnormalities. PH is an important complication thatnegatively affects mortality in patients with interstitial lung disease (ILD). ILD
comprises a wide range of lung diseases associated with fibrotic destruction of
the lung parenchyma and includes idiopathic pulmonary fibrosis (IPF), which
has a higher mortality than many types of cancer. MPAP of > 20 mm Hg at initialevaluation was reported to increase the mortality rate in patients with IPF, but
the clinical significance of PVR in patients with various types of ILD has notbeen fully elucidated.
In this study, we retrospectively analysed patients with ILD who underwent
right heart catheterisation (RHC) in the initial evaluation of ILD between April
2007 and April 2018.
Our data suggest that PVR was strongly associated with mortality, independentof existing predictors. Furthermore, we found that mild elevation of PVR (> 2Wood Units) was associated with higher mortality even in those with MPAP ≤ 20mm Hg.
We concluded that the simultaneous interpretation of PVR and MPAP isimportant in patients with ILD.

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Research BackgroundPulmonary hypertension (PH) is defined by elevated mean pulmonary arterialpressure (MPAP), and elevated pulmonary vascular resistance (PVR) reflects
pulmonary vascular abnormalities. PH is an important complication thatnegatively affects mortality in patients with interstitial lung disease (ILD). Mildelevation of MPAP is associated with mortality in some ILDs, but the clinicalsignificance of mild elevation of PVR has not been clarified. This is because
most hospitals in Japan and abroad do not perform right heart catheterisation(RHC) at the time of ILD diagnosis.

Research Results
In this study, we retrospectively analysed patients with ILD who underwent
right heart catheterisation (RHC) in the initial evaluation of ILD between April
2007 and April 2018.
These patients were classified by MPAP (20 mm Hg, 25 mm Hg) and PVR (2Wood Units: WU) using the 2022 ESC/ERS guidelines for PH. The clinicalsignificance of MPAP and PVR for mortality was analysed by the log-rank test.
We found that a PVR greater than 2 WU was associated with a higher mortality
rate regardless of the MPAP value (Figure 1).

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Furthermore, compared with MPAP, PVR showed better prognostic ability forthe mortality rate every year (Figure 2).

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Cox hazard analysis revealed that PVR > 2 WU was an independent predictor for
mortality from the existing ILD predictors, the ILD-GAP index. Moreover, PVR
but not MPAP was associated with a higher mortality rate (Table 1).

We determined the optimal cut-off value for PVR to be 2.2 WU (Figure 3).

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Research Summary and Future Perspective
We conclude that PVR>2 WU is associated with a higher mortality rate inpatients with ILD, regardless of MPAP values. Further studies are needed toreveal the importance of PVR, detect the patients who need right heart
catheterisation at the time of ILD diagnosis, elucidate the pathogenesis of ILD,and explore new approaches to managing patients with ILD.
Publication
Mild elevation of pulmonary vascular resistance predicts mortality regardless ofmean pulmonary artery pressure in mild interstitial lung disease

Thorax (electronic version dated February 5, 2024)
Tomonori Sato1, Taiki Furukawa1,2, Ryo Teramachi1,2, Jun Fukihara3,Yasuhiko Yamano3, Toshiki Yokoyama3, Toshiaki Matsuda3, Kensuke Kataoka3,
Tomoki Kimura3, Koji Sakamoto1, Makoto Ishii1, Yasuhiro Kondoh3
1 Department of Respiratory Medicine, Faculty of Medicine, Graduate School ofMedicine, Nagoya University, Nagoya, Japan
2 Medical IT Center, Nagoya University Hospital, Nagoya, Japan
3 Department of Respiratory Medicine and Allergy, Tosei General Hospital, Seto,Japan
DOI: 10.1136/thorax-2023-220179
Japanese ver.
https://www.med.nagoya-u.ac.jp/medical_J/research/pdf/Tho_240216.pdf

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