Open AccessThe prognostic relevance of oxygen uptake in inoperable chronic thromboembolic pulmonary hypertension
Author(s) -
Richter Manuel Jonas,
Pader Philip,
Gall Henning,
Reichenberger Frank,
Seeger Werner,
Mayer Eckhard,
Guth Stefan,
Kramm Thorsten,
Grimminger Friedrich,
Ghofrani Hossein A.,
Voswinckel Robert
Publication year - 2017
Publication title -
the clinical respiratory journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.789
H-Index - 33
eISSN - 1752-699X
pISSN - 1752-6981
DOI - 10.1111/crj.12399
Subject(s) - medicine , pulmonary hypertension , cardiology , univariate analysis , proportional hazards model , hazard ratio , vascular resistance , log rank test , multivariate analysis , survival analysis , blood pressure , confidence interval
Background Patients with chronic thromboembolic pulmonary hypertension (CTEPH) present with a decreased oxygen uptake, however, the prognostic relevance of oxygen uptake (VO 2 ) in inoperable CTEPH is unknown. Methods Patients with inoperable CTEPH were retrospectively analyzed. All patients were assessed by means of right heart catheterisation and cardio pulmonary exercise testing in semisupine position with a 30 Watt increment step‐protocol. Results One‐hundred and fifty‐one patients (82 female (54.3%), mean age 61 ± 12.4 years) presented with a mean pulmonary arterial pressure of 40.2 ± 14.2 mmHg and pulmonary vascular resistance (PVR) of 641.9 ± 374.8 dyne∗s/cm 5 . The peak VO 2 (mean 13.1 ± 4.5 mL∗kg −1 ∗min −1 ) was measured at initial referral. Over a follow‐up of up to 10 years (mean 4.41 ± 2.57 years), 31 patients had died. Patients with a baseline peak VO 2 ≥ 10.7 mL∗kg −1 ∗min −1 [area under the receiver‐operating characteristic curve (AUC) = 0.728, P = 0.001] had better survival than those with a peak VO 2 ≤ 10.7 mL∗kg −1 ∗min −1 using Kaplan–Meier analysis (88.8% vs 60.1%; log rank P = 0.001). Adjusting for age, gender and PVR, multivariate analysis identified peak VO 2 as a predictor of mortality [hazard ratio (HR): 2.78, 95% CI 1.01–7.63, P = 0.047]. In addition, peak VO 2 failed as an independent prognostic factor in a stepwise multivariate model including all variables significant in the univariate analysis. Conclusions In patients with inoperable CTEPH the peak VO 2 is a significant predictor of survival, when adjusting for age, gender and PVR. However, peak VO 2 failed as an independent prognostic factor when correcting for all significant baseline variables, which is limiting the clinical usability.