Carbon monoxide diffusing capacity and mortality in pulmonary arterial hypertension

Sonal Chandra, Sanjiv J Shah, Thenappan Thenappan, Stephen L Archer, Stuart Rich, Mardi Gomberg-Maitland
Journal of Heart and Lung Transplantation 2010, 29 (2): 181-7

BACKGROUND: Abnormal carbon monoxide diffusing capacity (DLCO) is a marker of pulmonary vascular disease and predicts the presence of pulmonary arterial hypertension (PAH) and poor prognosis in diseases such as systemic sclerosis and idiopathic pulmonary fibrosis. Little is known of its prognostic utility in World Health Organization (WHO) Group I PAH.

METHODS: We performed a cohort study of 408 patients with WHO Group I PAH from 1982 to 2006, with data on demographics, comorbidities, medications, functional class, laboratory tests, exercise testing, and hemodynamics. DLCO was determined upon entry into the study. We divided the cohort into tertiles based on DLCO and compared differences between groups. We used a Cox proportional hazards analysis to determine the association of DLCO with mortality, after adjusting for age, connective tissue disease etiology, functional class, pulmonary function testing variables, serum creatinine, albumin, hemoglobin, lung parenchymal abnormalities on chest computed tomography, oxygen use, and hemodynamic variables.

RESULTS: The lowest tertile of DLCO was independently associated with an increased risk of death (univariate hazard ratio [HR] = 2.7, 95% confidence interval [CI] 1.9 to 3.9, p < 0.0001; multivariate HR = 2.4, 95% CI 1.1 to 5.0, p = 0.025). On receiving operator characteristic (ROC) curve analysis, the c-statistic for the multivariate model without DLCO was 0.75, whereas the c-statistic for the multivariate model with DLCO was 0.78 (p = 0.003 by likelihood ratio test). Importantly, a multivariate model with hemodynamic variables alone (c-statistic = 0.61) was quite inferior to the multivariate model, which included DLCO.

CONCLUSION: DLCO is an independent predictor of death in patients with WHO Group I PAH.

Full Text Links

Find Full Text Links for this Article


You are not logged in. Sign Up or Log In to join the discussion.

Related Papers

Remove bar
Read by QxMD icon Read

Save your favorite articles in one place with a free QxMD account.


Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"