Pulmonary Hypertension in Interstitial Lung Disease: A Systematic Review and Meta-Analysis

Hui Li Ang; Max Schulte; Roseanne Kimberley Chan; Hann Hsiang Tan; Amelia Harrison; Christopher J Ryerson; Yet Hong Khor

doi:10.1016/j.chest.2024.04.025

Pulmonary Hypertension in Interstitial Lung Disease: A Systematic Review and Meta-Analysis

Chest. 2024 May 29:S0012-3692(24)00661-5. doi: 10.1016/j.chest.2024.04.025. Online ahead of print.

Authors

Hui Li Ang¹, Max Schulte², Roseanne Kimberley Chan³, Hann Hsiang Tan⁴, Amelia Harrison⁵, Christopher J Ryerson⁶, Yet Hong Khor⁷

Affiliations

¹ Royal Melbourne Hospital, VIC, Australia; Institute for Breathing and Sleep, VIC, Australia.
² Institute for Breathing and Sleep, VIC, Australia.
³ Department of Cardiology, Western Health, St. Albans, VIC, Australia.
⁴ Royal Sussex County Hospital, Brighton, England.
⁵ Department of Respiratory and Sleep Disorders Medicine, Western Health, St. Albans, VIC, Australia.
⁶ University of British Columbia, Vancouver, BC, Canada; Centre for Heart Lung Innovation, Vancouver, BC, Canada.
⁷ Central Clinical School, Monash University, Melbourne, VIC, Australia; Institute for Breathing and Sleep, VIC, Australia; Department of Respiratory and Sleep Medicine, Austin Health, Heidelberg, VIC, Australia. Electronic address: yet.khor@monash.edu.

PMID: 38821182
DOI: 10.1016/j.chest.2024.04.025

Abstract

Background: Pulmonary hypertension (PH) is a key complication in interstitial lung disease (ILD), with recent therapeutic advances.

Research question: What are the diagnostic evaluation, epidemiologic features, associated factors, prognostic significance, and outcome measures in interventional trials for PH in patients with ILD in the current literature?

Study design and methods: Ovid MEDLINE, Embase, and CENTRAL databases were searched for original research evaluating PH in participants with ILD of any cause. The definition of PH was based on the investigators' criteria.

Results: Three hundred two studies were included, with varying diagnostic evaluations used to define PH. Commonly used diagnostic tests were right heart catheterization (RHC; 56%) and transthoracic echocardiography (TTE; 50%). The pooled prevalence for PH in general populations with ILD was 36% (95% CI, 30%-42%) using RHC and 34% (95% CI, 29%-38%) using TTE. Lower diffusion capacity of the lungs for carbon monoxide, worse oxygenation status, reduced exercise capacity, increased pulmonary artery to aorta ratio and pulmonary artery diameter, and elevated serum brain natriuretic peptide consistently were associated with the presence of PH in at least 60% of reported studies. The presence of PH was associated with increased symptom burden and worse prognosis. Outcome measures in interventional trials of PH in ILD focused on changes in pulmonary vascular hemodynamics and 6-min walk distance.

Interpretation: PH is a common complication in ILD with significant health impacts. A standardized definition with prospective evaluation of risk-stratified assessments for PH using identified associated risk factors is warranted. Our findings provide an evidence base for validation as surrogate end points in future PH interventional trials in ILD.

Trial registry: International Prospective Register of Systematic Reviews; No.: CRD42021255394; URL: https://www.crd.york.ac.uk/prospero/.

Keywords: interstitial lung disease; pulmonary hypertension; systematic review.