Chest
Volume 136, Issue 1, July 2009, Pages 10-15
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Original Research
Interstitial Lung Disease
Idiopathic Pulmonary Fibrosis and Emphysema: Decreased Survival Associated With Severe Pulmonary Arterial Hypertension

https://doi.org/10.1378/chest.08-2306Get rights and content

Background

It has been suggested that the presence of emphysema modifies the outcome of patients with idiopathic pulmonary fibrosis (IPF). In this article we compare clinical features, smoking history, pulmonary function, estimated systolic pulmonary artery pressure (eSPAP), and mortality in IPF with emphysema vs IPF without emphysematous changes.

Methods

A cohort of 110 IPF patients was evaluated. Clinical data were collected from clinical charts. High-resolution CT (HRCT) scans were examined by an expert blinded to clinical data, and patients were classified into the following two groups: patients with IPF with emphysema; and patients with IPF without emphysema. The Kaplan-Meier method, log-rank test, and Cox regression model were used for statistical analyses.

Results

The prevalence of emphysema in the IPF cohort was 28% (31 of 110 patients). IPF with emphysema was significantly associated with male gender (odds ratio [OR], 18; 95% confidence interval [CI], 2.7 to 773.7; p = 0.0003), and smoking (OR, 3.8; 95% CI, 1.36 to 11.6; p = 0.004). Patients with IPF and emphysema had a higher mean (± SD) decrease in oxygen saturation during rest and exercise (16.3 ± 6.7% vs 13.5 ± 4.6%, respectively; p = 0.04), a higher mean fibrosis HRCT scan score (1.75 ± 0.36 vs 1.55 ± 0.38, respectively; p = 0.015), a higher eSPAP (82 ± 20 vs 57 ± 15 mm Hg, respectively; p < 0.0001), and lower median survival time (25 vs 34 months, respectively; p = 0.01) than patients with IPF without emphysema. The Cox regression model showed that the two most important variables associated with mortality were FVC < 50% predicted (hazard ratio [HR], 2.6; 95% CI, 1.19 to 5.68; p = 0.016) and eSPAP ≥ 75 mm Hg (HR, 2.25; 95% CI, 1.12 to 4.54; p = 0.022).

Conclusions

IPF patients with emphysema exhibited higher mortality compared with those with IPF without emphysema. This dire prognosis seems to be at least partially associated with the development of severe pulmonary arterial hypertension.

Section snippets

Materials and Methods

We evaluated the clinical records of a cohort of consecutive IPF patients at the National Institute of Respiratory Diseases (INER), Mexico, from 1996 through 2006. The diagnosis of IPF was made based on established criteria and was confirmed by lung biopsy in 38% of the subjects.10 All patients in whom IPF had been diagnosed before the year 2000 were reevaluated to confirm that they met the American Thoracic Society/European Respiratory Society consensus guidelines.10 Clinical data (ie, smoking

Results

We evaluated 198 patients with a diagnosis of IPF. From them, 113 patients had available the chest HRCT scan corresponding to the first medical evaluation; 3 patients were excluded from the study because they had HRCT scan findings that were nontypical for IPF and had not undergone a biopsy. Seventy-two percent of the 110 patients were men (mean [± SD] age, 64 ± 9.5 years), and 56% had a history of cigarette smoking. Male gender and smoking history were highly associated, as follows: 56 smokers

Discussion

A growing body of evidence suggests that IPF evolves with different clinical phenotypes. Thus, for example, in 2007 we described5 an accelerated variant of the disease in which patients consulted a physician a few months after the beginning of symptoms with severe physiologic impairment and showing a significantly lower survival rate. Also, it is well known that the disease occurs more frequently in smokers9, 17, 18 and that emphysematous changes develop in a number of these patients. In this

Acknowledgment

The authors thank Dr. Fortunato Juárez for her expert evaluation of the HRCT scans in the concordance analysis.

References (22)

  • RM Rudd et al.

    British Thoracic Society Study on cryptogenic fibrosing alveolitis: response to treatment and survival

    Thorax

    (2007)
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    This study was supported by Universidad Nacional Autónoma de México, grant No. SDI.PTID.05.6.

    The authors have reported to the ACCP that no significant conflicts of interest exist with any companies/organizations whose products or services may be discussed in this article.

    Reproduction of this article is prohibited without written permission from the American College of Chest Physicians (www.chestjournal.org/site/misc/reprints.xhtml).

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