[Results of one year pulse oxymetry in patients with chronic thromboembolic pulmonary hypertension]

It is little known on oxygen saturation in patients with chronic thromboembolic pulmonary hypertension (CTEPH).

To assess the occurrence, evolution and clinical significance of oxygen desaturations (D) during 1-year observation in CTEPH patients.

The study involved 24 consecutive patients with CTEPH (6 males, 18 females, mean age 63, range 22-75 years). During 24-hour pulse oxymetry mean oxygen saturation (SpO2), number and duration of desaturations, defined as at least a 6% drop of SO2, below 88%, lasting a minimum of 8 s, were recorded at baseline and after 6 and 12 months of follow-up. Simultaneously echocardiographic study and blood gases analysis was performed.

At baseline 18 of 24 (75%) CTEPH patients had desaturations. During follow-up none of nondesaturators had desaturations episodes and all baseline desaturators had desaturations episodes after 6 and 12 months. In desaturators there was trend to aggravate the number and duration of diurnal but not nocturnal desaturations episodes after 6 and 12 months. It was accompanied by trend (p = 0.05) to increase of pulmonary pressure as assessed by echocardiographic study, whereas the opposite trend to decrease of pulmonary pressure was seen in nondesaturators.

Results of the study show that desaturations occur in most patients with CTEPH and desaturators may have worse clinical course than nondesaturators. It may suggest the need for long oxygen therapy in desaturating CTEPH patients to slow down progression of the disease.