Does reduced lung diffusing capacity for carbon monoxide predict the presence of pulmonary hypertension?
OBJECTIVE
The objective of this study was to determine whether reduced lung diffusing capacity for carbon monoxide (DLCO) predicts the presence of pulmonary hypertension (PH) in heterogeneous group of patients.


METHODS
Consecutive patients who underwent pulmonary function and transthoracic echocardiographic testing within a 6-month period were retrospectively identified by chart review. Right ventricular systolic pressure (RVSP) was measured using Doppler echocardiography. PH was defined as a RVSP >30 mm Hg. Patients were divided into 2 major groups: those whose RVSP was < or =30 mm Hg and those whose RVSP was >30 mm Hg. PH was classified as mild (RVSP = 31-40 mm Hg), moderate (RSVP = 41-60 mm Hg) and severe (RVSP >60 mm Hg).


RESULTS
A total of 398 patients were entered into the study: 264 (66.3%) with PH and 134 (33.7%) without PH. Patients with PH were older, had a lower mean percentage of predicted values for forced vital capacity (%FVC), for DLCO (%DLCO) and for DLCO corrected for alveolar volume (%DLCO/VA) than those without PH. Multivariate analysis identified age and %FVC as independent predictors of PH [odds ratios and 95% confidence intervals of 1.038 (1.020-1.056) and 0.972 (0.955-0.988), respectively]. There was a weak, but significant negative correlation between RVSP and %DLCO (r = -0.205, P = 0.001), but there was no correlation between RVSP and %DLCO/VA. Neither %DLCO nor %DLCO/VA was found to be independent predictors of PH.


CONCLUSIONS
In a heterogeneous group of patients, %DLCO and %DLCO/VA do not independently predict the presence of PH.
Delcour
Kimberly S
KS
Division of Pulmonary and Critical Care Medicine, University of Missouri School of Medicine, Columbia, Missouri 65212, USA.
Singla
Atul
A
Jarbou
Mohammad
M
Alpert
Martin
M
Dabbagh
Ousama
O
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002248:Carbon Monoxide / Q000378:metabolism*; D005260:Female; D006801:Humans; D006976:Hypertension, Pulmonary / Q000175:diagnosis*; D008168:Lung / Q000000981:diagnostic imaging / Q000378:metabolism*; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D011237:Predictive Value of Tests; D011653:Pulmonary Diffusing Capacity; D012372:ROC Curve; D012129:Respiratory Function Tests; D012189:Retrospective Studies; D012307:Risk Factors; D013223:Statistics as Topic; D014463:Ultrasonography
D002248:Carbon Monoxide