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Background: Patients with chronic thromboembolic pulmonary disease (CTED) have persistent pulmonary vascular obstruction and exercise intolerance without pulmonary hypertension at rest and may benefit from pulmonary endarterectomy. However, up to now, CTED has been poorly characterized. Objectives: This study aimed to analyze the exercise capacity and limiting factors in CTED. Methods: We compared right heart catheterization and cardiopulmonary exercise test results of patients with CTED [mean pulmonary artery pressure (mPAP) at rest <25 mm Hg, n = 10], chronic thromboembolic pulmonary hypertension (CTEPH, n = 31) and a control group (n = 41) presenting with dyspnea but normal pulmonary vascular imaging and excluded pulmonary hypertension. Results: Subjects with CTED show a reduced oxygen uptake [median 76/interquartile range (IQR) 22% pred.] and work rate (median 76/IQR 21 W). The work rate was significantly lower compared to control subjects (p = 0.04) but not significantly different from CTEPH patients (p = 0.66). Oxygen pulse and breathing reserve were normal. CTED subjects showed decreased end-tidal CO 2 at anaerobic threshold (28.4/4.3 mm Hg), an elevated V E /V CO 2 slope (42.5/23.5), breathing equivalents (EQ O 2 32.0/8.7, EQ CO 2 39.5/8.8), alveolar-capillary oxygen gradient (34.7/15.5 mm Hg) and capillary end-tidal carbon dioxide gradient (8.8/5.7 mm Hg) compared to control subjects (p < 0.001). The degree of limitation was similar to that in CTEPH. Conclusions: Despite an mPAP of <25 mm Hg, subjects with CTED show objective functional impairment and similar limitations to patients with CTEPH. Functional limitation is characterized by gas exchange disturbance and ineffective ventilation. [ABSTRACT FROM AUTHOR]

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, the number of patients with undiagnosed CTEPH may be high. Objectives: We aimed to determine if cardiopulmonary exercise testing (CPET) could serve as complementary tool in the diagnosis of CTEPH and can detect CTEPH in patients with normal echocardiography. Methods: At diagnosis, we analyzed the data of CPET parameters in 42 patients with proven CTEPH and 51 controls, and evaluated the performance of two scores. Results: VE/VCO2 slope, EQO2, EQCO2, P(A-a)O2, end-tidal partial pressure of CO2 at anaerobic threshold (PETCO2) and capillary to end-tidal carbon dioxide gradient [P(c-ET)CO2] were significantly different between patients 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-parameter-CPET (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 it was normal in 13 patients (31%). All patients with normal or unmeasurable right ventricular systolic pressure had a pathological CPET. Twelve of the 13 patients (92%) were detected by both CPET scores. Conclusion: CPET is a useful noninvasive 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. © 2014 S. Karger AG, Basel [ABSTRACT FROM AUTHOR]

Pulmonary hypertension (PH) is a common consequence of COPD. It has been speculated that patients showing serious PH and vascular remodeling without severe airway obstruction might benefit from vasoactive treatment. There is no approved drug available for COPD-induced PH. Most trials assessing the efficacy of vasoactive drugs in PH have had a follow-up of 12--16 weeks. We report on 4 subjects with COPD and PH. Pulmonary arterial hypertension associated diseases and pulmonary embolism were ruled out. PH persisted despite optimized treatment of underlying COPD and comorbidities, so bosentan was started in all 4 subjects. With bosentan the mean pulmonary artery pressure improved. The average gains in 6-min walk distance at 2--3 months and 8--9 months were 36 m and 145 m, respectively. The maximum gains in 6-min walk distance of the individual subjects were at the 9th, 13th, and 18th month. Oxygenation was stable, and no side effects were observed. We suggest from this experience that in clinical trials of PH in COPD, a follow-up of 16 weeks might cause underestimation of the treatment effects. [ABSTRACT FROM AUTHOR]