Abstract 12059: End-Tidal CO2 Partial Pressure Measurement During Exercise Shows Early Pulmonary Arterial Hypertension in Scleroderma Patients
RATIONALE: Pulmonary arterial hypertension (PAH) is a known, devastating complication in patients (pts) with scleroderma (SSc). Non-invasive screening for PAH by echocardiography is recommended for these pts and prognostically relevant. Pathophysiological considerations suggest that exercise testing may add important diagnostic information for the early diagnosis of PAH.
HYPOTHESIS: We analyzed whether exercise gas exchange parameters differ in SSc pts with vs without PAH. We hypothesized that these parameters are able to distinguish between pts without PAH and pts with mild pulmonary artery pressure (PAP) elevation.
METHODS: We analyzed 43 consecutive SSc pts with dyspnea. None of the pts had previously been diagnosed with PAH. Each patient underwent right heart catheterization and cardiopulmonary exercise testing. PAH was diagnosed according to current guidelines. The pts were categorized into 3 groups: pts without PAH (group 1), pts with mild PAP elevation (mean 25-35 mmHg, group 2) and pts with high PAP elevation (mean > 35 mmHg, group 3). Gas exchange parameters were also compared to PAP measured by resting echocardiography.
RESULTS: In 22 out of 43 cases, PAH was invasively diagnosed. A mean PAP of 25-35 mmHg was found in 8 pts with PAH. The results are shown in table 1. While several parameters were able to distinguish between groups 1 and 2, only the difference in end-tidal CO2 partial pressure (PETCO2) between start of exercise and anaerobic threshold was able to show significant differences between all three groups.
CONCLUSIONS: PETCO2 correlates with hemodynamic parameters and is able to show significant differences between SSc patients without PAH and SSc pts with mild PAH. PETCO2 measured during exercise may reveal important clinical information on early changes in the pulmonary circulation and be of additional value for the non-invasive screening algorithm.
- © 2011 by American Heart Association, Inc.