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

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” patients. 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 ( VO 2 ), aerobic capacity ( AT ), peak partial pressure of end‐tidal CO 2 ( P ET CO 2 ), oxygen uptake efficiency plateau ( OUEP ), and oxygen uptake efficiency slope ( OUES ), along with higher minute ventilation ( VE )/carbon dioxide output ( VCO 2 ) slope and lowest VE / VCO 2 ( P < 0.001). VE / VCO 2 slope and AT were independent predictors of PH derived from multivariate logistic regression adjusted for age and body mass index. A score combining VE / VCO 2 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 / VCO 2 slope and AT provides high specificity in screening out PH from a pool of echocardiography‐suspected PH patients.