Significance of pulmonary arterial pressure and diffusion capacity of the lung as prognosticator in patients with idiopathic pulmonary fibrosis.
OBJECTIVE
To evaluate the long-term clinical course of patients with idiopathic pulmonary fibrosis (IPF) complicated with pulmonary arterial hypertension.


METHODS
Prospective analysis of consecutive IPF patients undergoing initial workup with right-heart catheterization (RHC) and pulmonary function testing (PFT). Pulmonary arterial pressure (PAP) and diffusion capacity of the lung for carbon monoxide (Dlco) were focused on.


METHODS
University hospital.


METHODS
Seventy-eight patients with IPF (67 men, 11 women; diagnosis by pathology, n = 59; clinical diagnosis, n = 19) had been followed up after initial workup for a maximum of 14 years.


RESULTS
RHC data on 61 patients and PFT data on 52 patients were available. Five-year survival rates were 62.2% in the normal-PAP group (mean PAP < 17 mm Hg, n = 37) and 16.7% in the high-PAP group (mean PAP > 17 mm Hg, n = 24) [p < 0.001]; 70.4% in the preserved-Dlco group (percentage of predicted > 40%, n = 27) and 20.0% in the low-Dlco group (percentage of predicted < 40%, n = 25) [p < 0.001]; and 82.6% in group 1 (normal PAP and preserved Dlco, n = 23) and 15.6% in group 2 (high PAP, low Dlco, or both, n = 32) [p < 0.0001]. The relative risks of mortality within 5 years after RHC were 2.20 (95% confidence interval [CI], 1.40 to 3.45) in the high-PAP group, 2.70 (95% CI, 1.46 to 4.99) in the low-Dlco group, and 4.85 (95% CI, 1.97 to 11.97) in group 2.


CONCLUSIONS
Dlco was a critical factor for evaluating disease status and prognosis, and PAP status provided feasible information in the initial workup of IPF patients.
Hamada
Kunio
K
Chitose City Hospital, Division of Internal Medicine, Chitose, Hokkaido. Electronic address: kunio.hamada@city.chitose.hokkaido.jp.
Nagai
Sonoko
S
Kyoto University Hospital, Department of Respiratory Medicine, Kyoto.
Tanaka
Shigeru
S
Mojukai Tanaka Clinic, Osaka.
Handa
Tomohiro
T
Kyoto University Hospital, Department of Respiratory Medicine, Kyoto.
Shigematsu
Michio
M
Sumitomo Hospital, Division of Respiratory Medicine, Osaka.
Nagao
Taishi
T
Shiga University of Medical Science, Department of Respiratory Medicine, Otsu, Shiga.
Mishima
Michiaki
M
Kyoto University Hospital, Department of Respiratory Medicine, Kyoto.
Kitaichi
Masanori
M
Kinki Chest Disease Center, Sakai, Osaka.
Izumi
Takateru
T
Central Clinic in Kyoto, Kyoto, Japan.
D000368:Aged; D006328:Cardiac Catheterization; D005240:Feasibility Studies; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D006976:Hypertension, Pulmonary / Q000175:diagnosis* / Q000401:mortality / Q000503:physiopathology; D008297:Male; D008875:Middle Aged; D010100:Oxygen / Q000097:blood; D011237:Predictive Value of Tests; D011379:Prognosis; D011446:Prospective Studies; D011653:Pulmonary Diffusing Capacity / Q000502:physiology*; D011658:Pulmonary Fibrosis / Q000175:diagnosis* / Q000401:mortality / Q000503:physiopathology; D011669:Pulmonary Wedge Pressure / Q000502:physiology*; D015996:Survival Rate; D014797:Vital Capacity / Q000502:physiology
D010100:Oxygen