Cardiopulmonary exercise testing improves diagnostic specificity in patients with echocardiography-suspected pulmonary hypertension.

Clin Cardiol. 2017 Feb;40(2):95-101. doi: 10.1002/clc.22635. Epub 2016 Nov 2.

Zhao QH(1), Wang L(1), Pudasaini B(1), Jiang R(1), Yuan P(1), Gong SG(1), Guo
J(2), Xiao Q(1), Liu H(1), Wu C(3), Jing ZC(4), Liu JM(1,)(2).

(1)Department of Pulmonary Circulation, Shanghai Pulmonary Hospital, Tongji
University, School of Medicine, Shanghai, China. (2)Department of Pulmonary
Function, Shanghai Pulmonary Hospital, Tongji University, School of Medicine,
Shanghai, China. (3)Department of Statistics, the Second Military Medical
University, Shanghai, China. (4)State Key Laboratory of Cardiovascular Disease,
Fu Wai Hospital, Peking Union Medical College and Chinese Academy of Medical
Science, Beijing, China.

BACKGROUND: Doppler echocardiography is usually the first diagnostic
investigation for patients suspected with pulmonary hypertension (PH), but it is
often inaccurate when used alone, especially in mild PH.
HYPOTHESIS: Cardiopulmonary exercise testing (CPET) may serve as a complementary
tool to improve diagnostic accuracy in echocardiography-suspected “PH possible”
METHODS: Eighty-eight consecutive patients with suspected PH (referred to as “PH
possible” hereafter) based on echocardiography were included in the study. CPET
was assessed subsequently and PH was confirmed by right-heart catheterization in
all subjects. We analyzed CPET data from patients and derived a CPET prediction
rule to hemodynamically differentiate PH.
RESULTS: Eighty-eight patients (27 patients with confirmed PH, and PH ruled out
in 61 patients) were included in the study. Compared with non-PH patients, the PH
subjects had lower peak oxygen uptake (VO2 ), aerobic capacity (AT), peak partial
pressure of end-tidal CO2 (PET CO2 ), oxygen uptake efficiency plateau (OUEP),
and oxygen uptake efficiency slope (OUES), along with higher minute ventilation
(VE)/carbon dioxide output (VCO2 ) slope and lowest VE/VCO2 (P < 0.001). VE/VCO2
slope and AT were independent predictors of PH derived from multivariate logistic
regression adjusted for age and body mass index. A score combining VE/VCO2 slope
and AT reached a high area under the curve value of 0.98. A score ≥0.5 had 95%
specificity and 92.6% sensitivity for diagnosis of PH.
CONCLUSIONS: A score combining VE/VCO2 slope and AT provides high specificity in
screening out PH from a pool of echocardiography-suspected PH patients.