Idiopathic Pulmonary Fibrosis (IPF)
Conditions
Interventions
None listed
Sponsors
Nippon Medical School
Eligibility
Sex/Gender
All
Inclusion criteria
Inclusion criteria: Adults aged 18 years or older. Diagnosed with idiopathic pulmonary fibrosis (IPF) by multidisciplinary discussion (MDD) according to ATS/ERS/JRS/ALAT criteria based on high-resolution computed tomography (HRCT) findings. Underwent both right heart catheterization (RHC) and comprehensive transthoracic echocardiography within the same hospitalization, performed within 30 days (<=60 days allowable). Evaluated under stable clinical conditions, defined as no acute exacerbation, respiratory infection, hospitalization, or steroid escalation within the preceding 4-8 weeks. Availability of complete hemodynamic data (mPAP, PAWP, cardiac output) and analyzable Doppler waveforms for right ventricular isovolumetric relaxation time (IRT) and pulmonary artery acceleration time (PAAcT). Patients receiving antifibrotic therapy (pirfenidone or nintedanib) were eligible if treatment had been stable for at least four weeks prior to evaluation. Patients with combined pulmonary fibrosis and emphysema (CPFE) were excluded; however, limited paraseptal or centrilobular emphysema involving less than 10 percent of the total lung field was acceptable.
Exclusion criteria
Exclusion criteria: Presence of left-sided heart disease (left ventricular ejection fraction <50%, moderate-to-severe valvular disease, or hypertrophic/restrictive cardiomyopathy). Pulmonary artery wedge pressure (PAWP) >15 mmHg. Combined pulmonary fibrosis and emphysema (CPFE) as determined by two pulmonologists and one radiologist, defined as upper-lobe predominant emphysema coexisting with lower-lobe predominant fibrosis on HRCT. Chronic thromboembolic pulmonary hypertension confirmed by CT pulmonary angiography or ventilation-perfusion (V/Q) scanning. Non-IPF interstitial lung diseases, including connective tissue disease-associated ILD, hypersensitivity pneumonitis, or sarcoidosis. Atrial fibrillation or other significant arrhythmias interfering with accurate time-interval measurements. Poor echocardiographic image quality precluding reliable Doppler waveform analysis. Missing key hemodynamic or echocardiographic data (mPAP, PAWP, cardiac output, IRT, PAAcT, etc.). Patients who had initiated pulmonary arterial hypertension-specific therapy prior to RHC or echocardiographic evaluation. Patients with acute exacerbation, respiratory infection, or clinically unstable condition at the time of evaluation.
Design outcomes
Primary
| Measure | Time frame |
|---|---|
| The relationship between right ventricular isovolumetric relaxation time (IRT) and pulmonary vascular resistance (PVR). The primary outcome is the strength of association (correlation coefficient and regression coefficient) between IRT and PVR. The pulmonary vascular resistance index (PVRI), adjusted for body surface area, will also be analyzed as a supplementary parameter. | — |
Secondary
| Measure | Time frame |
|---|---|
| Relationships between hemodynamic parameters obtained from right heart catheterization (mPAP, PAWP, PVR, PVRI, etc.) and clinical indices including %DLCO, %FVC, 6-minute walk distance and mMRC. Stepwise changes in IRT and related variables across pulmonary hypertension severity groups (No-PH, Borderline, PH), assessed by Spearman trend analysis. Exploratory analyses of associations among other physiologic and clinical variables, as appropriate. | — |
Countries
Japan
Contacts
Public ContactYosuke Tanaka
Nippon Medical School Hospital Department of Respiratory Medicine
Outcome results
None listed