Prediction of pulmonary hypertension in idiopathic pulmonary fibrosis.
BACKGROUND
Reliable, noninvasive approaches to the diagnosis of pulmonary hypertension in idiopathic pulmonary fibrosis are needed. We tested the hypothesis that the forced vital capacity to diffusing capacity ratio and room air resting pulse oximetry may be combined to predict mean pulmonary artery pressure (MPAP) in idiopathic pulmonary fibrosis.


METHODS
Sixty-one idiopathic pulmonary fibrosis patients with available right-heart catheterization were studied. We regressed measured MPAP as a continuous variable on pulse oximetry (SpO(2)) and percent predicted forced vital capacity (FVC) to percent-predicted diffusing capacity ratio (% FVC/% DL(co)) in a multivariable linear regression model.


RESULTS
Linear regression generated the following equation: MPAP=-11.9+0.272 x SpO(2)+0.0659 x (100-SpO(2))(2)+3.06 x (% FVC/% DL(co)); adjusted R(2)=0.55, p<0.0001. The sensitivity, specificity, positive predictive and negative predictive value of model-predicted pulmonary hypertension were 71% (95% confidence interval (CI): 50-89%), 81% (95% CI: 68-92%), 71% (95% CI: 51-87%) and 81% (95% CI: 68-94%).


CONCLUSIONS
A pulmonary hypertension predictor based on room air resting pulse oximetry and FVC to diffusing capacity ratio has a relatively high negative predictive value. However, this model will require external validation before it can be used in clinical practice.
Zisman
David A
DA
Department of Medicine, Division of Pulmonary and Critical Care Medicine, David Geffen School of Medicine, University of California, Los Angeles, CA 90095, USA. dzisman@mednet.ucla.edu
Ross
David J
DJ
Belperio
John A
JA
Saggar
Rajan
R
Lynch
Joseph P
JP
Ardehali
Abbas
A
Karlamangla
Arun S
AS
D005260:Female; D005541:Forced Expiratory Volume / Q000502:physiology; D006801:Humans; D006976:Hypertension, Pulmonary / Q000150:complications / Q000175:diagnosis* / Q000503:physiopathology; D008297:Male; D010100:Oxygen / Q000097:blood; D010313:Partial Pressure; D011237:Predictive Value of Tests; D011658:Pulmonary Fibrosis / Q000150:complications* / Q000503:physiopathology; D011669:Pulmonary Wedge Pressure / Q000502:physiology; D012189:Retrospective Studies; D014797:Vital Capacity / Q000502:physiology
D010100:Oxygen