Outcomes of patients with decreased arterial oxyhaemoglobin saturation on pulmonary arterial hypertension drugs

Abstract

RationaleDrugs approved for the treatment of pulmonary arterial hypertension (PAH) improve long-term outcomes. These drugs have pulmonary vasodilator properties which may potentially cause a decrease in arterial oxyhaemoglobin saturation (SaO2) in some patients.ObjectivesThe present retrospective study of the French PAH Registry aimed to describe clinical characteristics and outcomes of patients showing a ≥3% decrease in SaO2 while treated with PAH drugs.MethodsWe reviewed 719 PAH patients. The exclusion criteria were PAH associated with congenital heart disease and PAH with overt features of venous/capillaries involvement.Main ResultsOne hundred and seventy-three (24%) patients had a ≥3% decrease in SaO2. At diagnosis, they were older, with a lower diffusion capacity for carbon monoxide and a shorter 6-minute walk distance, when compared to those who did not display a ≥3% decrease in SaO2. The percentage of patients meeting the ESC/ERS low risk criteria at re-evaluation was significantly lower in those with a ≥3% decrease in SaO2 and more patients started long-term oxygen therapy in this group (16% versus 5%, p<0.001). A≥3% decrease in SaO2 was associated with a poorer survival (Hazard Ratio 1.81:95% confidence interval 1.43–2.34; p<0.0001). In a multivariate Cox analysis, a ≥3% decrease in SaO2 was a prognostic factor independent of age at diagnosis and ESC/ERS risk stratification at follow-up.ConclusionsWhen treated with PAH drugs, a large subset of patients experience a≥3% decrease in SaO2, which is associated with worst long-term outcomes and reduced survival.

Oxygenated hemoglobin as prognostic marker among patients with systemic sclerosis screened for pulmonary hypertension

“…Hoeper et al reported that oxygenation was not a prognostic marker for survival among prevalent patients with idiopathic PAH under therapy, which supports our results 19 . Recently, Valentin et al (2021) showed that oxygen desaturation (SaO 2 ) ≥ 3% at the time of the first follow-up after one year in combination with low DLCO was significantly associated with worse prognosis of PAH 20 , matching our results linking low OxyHem and low DLCO with early PVD. In this cohort, male sex did not correlate with survival consistent with results from the literature 6 , 21 , 22 .…”

2022 ESC/ERS Guidelines for the diagnosis and treatment of pulmonary hypertension

“…449 Moreover, in patients with a cardiopulmonary phenotype, PAH medication may cause a decline in the peripheral oxygen saturation. 452 There is little published experience on the use of prostacyclin analogues or prostacyclin receptor agonists in this patient population. 453 The lack of solid evidence for treating elderly patients with PAH and cardiopulmonary comorbidities makes treatment recommendations challenging, and patients should be counselled accordingly.…”

Circulating Blood-Based Biomarkers in Pulmonary Hypertension

“…Interestingly, in the same study, the improvement of pCO2 after 3 months of PAH targeted therapy was noted, and that was associated with higher survival rate [113]. However, a recent study conducted by Valentin et al revealed that in PAH patients, a ≥3% decrease in arterial oxyhemoglobin saturation (SaO2), noticed after 3 months of treatment with PAH-specific drugs, was associated with worse outcomes [114].…”