0
Correspondence |

Response FREE TO VIEW

Eric Hachulla, MD, PhD; David Launay, MD, PhD; Pierre Clerson, MD; Marc Humbert, MD, PhD; for the French PAH-SSc Network
Author and Funding Information

From the Department of Internal Medicine (Drs Hachulla and Launay), National Reference Center for Scleroderma, Hôpital Claude Huriez, University of Lille 2; Orgamétrie Biostatistiques (Dr Clerson); and the Respiratory Department (Dr Humbert), National Reference Center for Pulmonary Hypertension, Hôpital Antoine Béclère, Assistance Publique Hôpitaux de Paris, Université Paris-Sud 11.

Correspondence to: Eric Hachulla, MD, PhD, Department of Internal Medicine, Hôpital Claude Huriez, 59037 Lille Cedex, France; e-mail: ehachulla@chru-lille.fr


Financial/nonfinancial disclosures: The authors have reported to CHEST that no potential 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.chestpubs.org/site/misc/reprints.xhtml).


© 2010 American College of Chest Physicians


Chest. 2010;138(2):462-463. doi:10.1378/chest.10-0799
Text Size: A A A
Published online

To the Editor:

The correspondence by Campo et al regarding our recent publication in CHEST (November 2009)1 emphasizing that systemic sclerosis-associated pulmonary arterial hypertension (PAH-SSc) may occur early in the course of the disease (ie, within the first 5 years of systemic sclerosis [SSc]-related, non-Raynaud phenomenon symptoms) is of great interest. Indeed, for the first time, two teams, one in the European Union and one in the United States, independently have shown that PAH-SSc may be an early complication of SSc in up to one-half of the cases. As a consequence, we both recommend that screening for pulmonary arterial hypertension (PAH) should be considered immediately after the occurrence of the first SSc-related non-Raynaud phenomenon symptom.

Campo et al then focus their discussion on the threshold of the diffusion capacity of carbon monoxide (Dlco) (35% of predicted value) that we have found to be an independent risk of death in our population of patients with PAH-SSc (hazard ratio, 2.587; 95% CI, 1.029–6.501; P = .04). Obviously, Dlco may be reduced not only because of pulmonary vascular disease but also because of comorbid interstitial lung disease (ILD), which is not uncommon in such patients. Distinguishing pure PAH from pulmonary hypertension (PH) due to hypoxia associated with lung fibrosis in patients with SSc may be challenging, and both conditions are sometimes associated. Patients with evidence of ILD, as demonstrated by abnormal high-resolution CT scans of the chest and total lung capacity (TLC) ranging from 60% to 70% with elevated mean pulmonary arterial pressure >25 mm Hg at rest, were kept in the analysis set in case of the absence of extensive ILD or severe lung fibrosis, based on the expertise of our team, because they were considered more likely to have PAH-SSc rather than ILD-associated PH. We agree that such patients may be difficult to classify and that some may have quite severe ILD, which could contribute to PH. In order to address this comment, we have reanalyzed our data after exclusion of all patients with a TLC<70% and found a 40% cutoff of predicted Dlco value to be an independent risk of death at 3 years in patients with PAH-SSc (hazard ratio, 11.25; 95% CI, 1.38-91.60; P = .02). These consistent results suggest that Dlco is likely to be an important and relevant prognosis factor in patients with PAH-SSc. ILD, PH due to ILD, and PAH are not the sole causes of Dlco impairment in patients with SSc. Nevertheless, for clinical practice, it seems important to highlight the fact that a markedly impaired Dlco<35% to 40% of predicted value in patients with PAH-SSc may be associated with a worst-outcome scenario.

Hachulla E, Launay D, Mouthon L, et al; for the French PAH-SSc Network for the French PAH-SSc Network Is pulmonary arterial hypertension really a late com­plication of systemic sclerosis? Chest. 2009;1365:1211-1219. [CrossRef] [PubMed]
 

Figures

Tables

References

Hachulla E, Launay D, Mouthon L, et al; for the French PAH-SSc Network for the French PAH-SSc Network Is pulmonary arterial hypertension really a late com­plication of systemic sclerosis? Chest. 2009;1365:1211-1219. [CrossRef] [PubMed]
 
NOTE:
Citing articles are presented as examples only. In non-demo SCM6 implementation, integration with CrossRef’s "Cited By" API will populate this tab (http://www.crossref.org/citedby.html).

Some tools below are only available to our subscribers or users with an online account.

Related Content

Customize your page view by dragging & repositioning the boxes below.

  • CHEST Journal
    Print ISSN: 0012-3692
    Online ISSN: 1931-3543