Abstract 14536: Non-Invasive Evaluation of the Severity of Chronic Thromboembolic Pulmonary Hypertension With Ventilatory Gas Analysis
Background: Chronic thromboembolic pulmonary hypertension (CTEPH) is characterized by organic thrombotic obstructions of pulmonary arteries, leading to reduced pulmonary vascular reserve and right heart failure. In order to develop a non-invasive method to evaluate the severity of CTEPH, we examined whether the ventilatory gas analysis in different postures is useful for assessing pulmonary vascular reserve.
Methods and Results: We enrolled 80 consecutive CTEPH patients (64±15 year-old, M/F 7/73) treated with optimal treatments, including surgical therapies and/or catheter intervension, and 9 controls without PH (62±17 year-old, female 7/9). We performed right heart catheterization and the ventilatory gas analysis. Various parameters of pulmonary functions were evaluated in two postures; sitting and supine, and changes in the parameters were calculated (Δ(supine–upright)). Among the CTEPH patients, mean pulmonary arterial pressure (mPAP) after medical treatment was below 25mmHg in 39 (20±3 mmHg, non-PH group) and still remained above 25mmHg in 41 (34±8 mmHg, PH group). The PH group had lowerΔPETCO2 and higherΔVE/VCO2 compared with the non-PH (both P<0.001) and the control group (both P<0.001) (Figure A). Importantly,ΔPETCO2 was significantly lower in the non-PH group than in the control group (P<0.001), whereas hemodynamics were comparable between the two groups. The ROC curve analysis showed that ΔPETCO2 was able to differentiate the PH group from the non-PH group (AUC=0.84, P<0.001) (Figure B). Moreover, in CTEPH patients, supine PETCO2 was significantly correlated with mPAP and pulmonary vascular resistance (PVR) (r=-0.602 and r=-0.633, respectively, both P<0.001)
Conclusions: These results indicate that the ventilatory gas analysis in different postures is an useful tool to differentiate CTEPH with mPAP≥25mmHg from non-PH and for non-invasive evaluation of the severity of CTEPH.
Author Disclosures: M. Akizuki: None. K. Sugimura: None. T. Aoki: None. T. Kakihana: None. O. Ito: None. H. Shimokawa: Speakers Bureau; Modest; Daiichi-Sankyo, Bayer Yakuhin. M. Kohzuki: None.
- © 2016 by American Heart Association, Inc.