MONDAY, Aug. 28, 2017 (HealthDay News) — End-tidal carbon dioxide (ETCO2) levels are prognostic for patients with chronic thromboembolic pulmonary hypertension (CTEPH), according to a letter to the editor published online Aug. 14 in the Annals of the American Thoracic Society.
Manuel J. Richter, M.D., from the Kerckhoff Heart and Thoracic Center in Bad Nauheim, Germany, and colleagues retrospectively analyzed data from the Giessen Pulmonary Hypertension Registry for 151 patients with inoperable CTEPH. Baseline ETCO2 levels obtained at rest were available for all patients.
The researchers found that 27.2 percent of the patients died during a mean follow-up of 64.8 ± 40.2 months. The median ETCO2 at baseline was 27 mm Hg, which was substantially decreased. ETCO2 was related to overall survival as a continuous variable in univariate analysis (hazard ratio, 0.91). Significantly impaired pulmonary hemodynamics and a more advanced functional class were seen for patients with inoperable CTEPH who had ETCO2 <29 mm Hg compared with ≥29 mm Hg. There was a significant correlation for ETCO2 dichotomized at 29 mm Hg with overall survival (hazard ratio, 0.37). Five-year overall survival was significantly better for patients with inoperable CTEPH and ETCO2 ≥29 mm Hg versus <29 mm Hg (89.3 versus 73.2 percent).
“ETCO2 emerged as a clinically relevant prognostic factor not only in pulmonary arterial hypertension but also in inoperable CTEPH, mirroring the presence of ventilation/perfusion mismatch as a pathophysiological hallmark in both disease entities,” the authors write.
Several authors disclosed financial ties to the pharmaceutical industry.
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