Subscribe to RSS
DOI: 10.1055/s-0034-1375931
Cardiopulmonary exercise testing to detect chronic thromboembolic pulmonary hypertension in patients with normal echocardiography
Background: Chronic thromboembolic pulmonary hypertension (CTEPH) is a serious complication of pulmonary embolism (PE). Taking into account the reported incidence of CTEPH after acute PE, there might be a high rate of patients with undiagnosed CTEPH.
Objectives: We aimed to determine if cardiopulmonary exercise testing (CPET) could serve as complementary tool in diagnosis of CTEPH and can detect CTEPH in patients with normal echocardiography.
Methods: We analysed the data of CPET parameters at diagnosis of 42 subjects with proven CTEPH and 51 controls and evaluated the performance of two scores.
Results: VE/VCO2-Slope, EQO2, EQCO2, P(A-a)O2, PETCO2 and capillary to end-tidal carbon dioxide gradient P(c-ET)CO2 were significantly different between subjects with CTEPH and controls (p < 0.001). P(c-ET)CO2 was the single parameter with the highest sensitivity (85.7%) and specificity (88.2%). A score combining VE/VCO2-Slope, P(A-a)O2, P(c-ET)CO2, PETCO2 (4-P-CPET-Score) reached a sensitivity of 83.3% and a specificity of 92.2% after cross-validation. In 42 patients with CTEPH, echocardiography identified PH in 29 patients (69%), but was normal in 13 patients (31%). All patients with normal or not measurable right ventricular systolic pressure had a pathological CPET. Twelve of these subjects (92%) were detected by both CPET-Scores.
Conclusion: CPET is a useful non-invasive diagnostic tool for the detection of CTEPH in patients with suspected PH but normal echocardiography. The 4-P-CPET-Score provides a high sensitivity with the highest specificity.