The following is a summary of “Does arterial oxygenation during exercise add prognostic value in pulmonary arterial hypertension?,” published in the January 2023 issue of Pulmonology by Restoy, et al.
When determining a patient’s prognosis for pulmonary arterial hypertension (PAH), the 6-min walking distance (6MWD) was frequently employed. However, uncertainty existed over whether variations in arterial oxygen saturation (SpO2) during exercise improved the predictive value of the 6MWD in these individuals. For a study, researchers sought to determine if variations in SpO2 during exercise improved the predictive value of the 6MWD in PAH patients.
About 137 individuals with PAH were included in the ambispective research; there were 38 cases of idiopathic/heritable (i/h PAH), 42 with connective tissue disease (CTD-PAH), 34 cases of Porto-pulmonary hypertension (PoPH), 21 cases of HIV-associated PAH, and 2 cases of pulmonary venous occlusive disease (PVOD). Patients were assessed, treated according to international guidelines, and monitored for 5 years. Desaturation distance ratio (DDR) was computed either in its original form (from a maximum theoretical value of 100%) or real resting SpO2 values of the patient (new DDR) and the distance saturation product (DSP) to include SpO2 variations during exercise.
About 40 patients died during follow-up (29.2%); findings verified the predictive usefulness of the 6MWD (AUC 0.913 [IQR 0.868-0.958]; P<0.0001); original DDR (AUC 0.923 [0.881-0.966]; P< 0.001); new DDR (AUC 0.917 [0.872-0.961]; P< 0.001); and DSP (AUC 0.914 [0.869–0.959], P < 0.001); and, neither the original or new DDR nor DSP added significant prognostic value to 6MWD in the patients.
The predictive value of the 6MWD in patients with PAH was not increased when three separate composite measures of changes in arterial oxygenation during exercise were taken into account.