Journal Article

Prevalence and Outcomes of Pulmonary Arterial Hypertension in Advanced Idiopathic Pulmonary Fibrosis

Ahmad, Shahzad, Nathan, Steven D., Barnett, Scott D., Shorr, Andrew F., Lettieri, Christopher J.

2006

Overview

The development of pulmonary arterial hypertension (PAH) can complicate many interstitial lung diseases, including idiopathic pulmonary fibrosis (IPF). We sought to characterize the prevalence of PAH and its impact on survival in patients with advanced IPF. Retrospective analysis of consecutive IPF patients undergoing pretransplantation right heart catheterization. Lung transplant and IPF referral center. PAH was defined as a mean pulmonary artery pressure (mPAP) of > 25 mm Hg. We compared demographic, spirometric, 6-min walk test (6MWT) results, and survival outcomes between those with PAH and those without PAH. Seventy-nine patients were included in the study. PAH was present in 31.6% of patients (mean [± SD] mPAP, 29.5 ± 3.3 vs 19.1 ± 3.7 mm Hg, respectively). Those patients with PAH had a lower mean diffusing capacity of the lung for carbon monoxide (Dlco) (37.6 ± 11.3% vs 31.1 ± 10.1%, respectively; p = 0.04) and were more likely to require supplemental oxygen (66.7% vs 17.6%, respectively; p < 0.0001). Mean distance walked (143.5 ± 65.5 vs 365.9 ± 81.8 m, respectively; p < 0.001) and mean pulse oximetric saturation nadir (80.1 ± 3.7% vs 88.0 ± 3.5%, respectively; p < 0.001) during the 6MWT were also lower among those with PAH. PAH was associated with a greater risk of death during the study period (mortality rate, 60.0% vs 29.9%, respectively; odds ratio, 2.6; 95% confidence interval [CI], 2.3 to 3.1; p = 0.001). One-year mortality rates were higher in those with PAH (28.0% vs 5.5%, respectively; p = 0.002). As a predictor of mortality, PAH had a sensitivity, specificity, and accuracy of 57.1%, 79.3%, and 73.4%, respectively. There was a linear correlation between mPAP and outcomes with higher pressures associated with a greater risk of mortality (hazard ratio, 1.09; 95% CI, 1.02 to 1.16). FVC and Dlco did not predict outcomes. PAH is common in advanced cases of IPF and significantly impacts survival. A reduced Dlco, supplemental oxygen requirement, or poor 6-min walk performance should raise suspicion of the presence of underlying PAH. Identifying PAH might be an important adjunct in monitoring disease progression, triaging for transplantation, and guiding therapy.

• Publisher: Elsevier Inc,American College of Chest Physicians
• Subject: 6MWT = 6-min walk test / Biological and medical sciences / Carbon monoxide / Cardiac catheterization / Cardiology. Vascular system / catheterization / CI = confidence interval / Comorbidity / Confidence intervals / Dlco = diffusing capacity of the lung for carbon monoxide / Ejection fraction / Exercise Test / Female / HR = hazard ratio / Humans / Hypertension, Pulmonary - diagnosis / Hypertension, Pulmonary - epidemiology / Hypertension, Pulmonary - etiology / ILD = interstitial lung disease / Intubation / IPF = idiopathic pulmonary fibrosis / Lung diseases / Lung transplants / LV = left ventricular / Male / Medical sciences / Middle Aged / Mortality / mPAP = mean pulmonary arterial pressure / PA = pulmonary artery / PAH = pulmonary arterial hypertension / Patients / PAWP = pulmonary artery wedge pressure / PFT = pulmonary function test / Pneumology / Prevalence / Proportional Hazards Models / Pulmonary arteries / pulmonary artery / Pulmonary fibrosis / Pulmonary Fibrosis - complications / Pulmonary Fibrosis - epidemiology / Pulmonary Fibrosis - mortality / pulmonary function tests / Pulmonary hypertension / Pulmonary hypertension. Acute cor pulmonale. Pulmonary embolism. Pulmonary vascular diseases / Respiratory system : syndromes and miscellaneous diseases / Sensitivity and Specificity / Spirometry / Spo2 = pulse oximetric saturation / Survival Analysis / TLC = total lung capacity / Veins & arteries