Cardiopulmonary exercise test characteristics in patients with chronic obstructive pulmonary disease and associated pulmonary hypertension.
BACKGROUND
Pulmonary hypertension (PH) is a well-known complication of chronic obstructive pulmonary disease (COPD). It remains unclear whether exercise parameters can be used to discriminate between COPD patients with associated PH (COPD-PH) and COPD patients without associated PH (COPD-nonPH).


OBJECTIVE
To study whether the existence of pulmonary hypertension in COPD is related to characteristic findings in gas exchange and circulatory parameters during cardiopulmonary exercise testing (CPET).


METHODS
We retrospectively analyzed CPET data in 25 COPD patients in whom right heart catheterization had been performed. Differences were assessed between COPD-PH and COPD-nonPH patients in peak oxygen uptake (VO(2) peak), ventilatory efficiency (VE/VCO(2)), oxygen pulse, maximal ventilation and pulse oximetry (S(p)O(2)).


RESULTS
PH was found in 10 of 25 patients (mP(pa) = 33 +/- 7 mm Hg), in 15 patients mean pulmonary artery pressure (mP(pa)) was below 25 mm Hg (18 +/- 3 mm Hg). CPET in COPD-PH was characterized by a higher VE/VCO(2) at nadir, a higher VE/VCO(2) slope, and a lower S(p)O(2) at rest and during exercise, but values in both groups were overlapping considerably. In the whole group mP(pa) was associated with resting P(a)O(2) (r = -0.70, p < 0.001), VE/VCO(2) nadir (r = 0.43, p < 0.05), and inversely related to S(p)O(2) at rest and during exercise (r = -0.58 and r = -0.64, p < 0.01, respectively).


CONCLUSIONS
Although CPET characteristics showed a large overlap in both groups, the existence of PH in COPD is associated with a significantly reduced ventilatory efficiency during CPET. However, a low S(p)O(2) at rest and a further decrease during exercise similarly suggest the presence of PH in COPD.
Holverda
Sebastiaan
S
Department of Pulmonary Diseases, Institute for Cardiovascular Research, VU University Medical Center, Amsterdam, The Netherlands.
Bogaard
Harm J
HJ
Groepenhoff
H
H
Postmus
Pieter E
PE
Boonstra
Anco
A
Vonk-Noordegraaf
Anton
A
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D006328:Cardiac Catheterization; D005080:Exercise Test; D005260:Female; D006801:Humans; D006976:Hypertension, Pulmonary / Q000175:diagnosis* / Q000209:etiology; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D029424:Pulmonary Disease, Chronic Obstructive / Q000150:complications*; D012129:Respiratory Function Tests