Key result
A breathing reserve ≤30% at peak exercise was associated with a significantly higher risk of mortality in patients with Eisenmenger syndrome at 10 years follow-up (HR 3.4).
Why the study?
Breathing reserve at peak exercise during CPET as a prognostic marker in PAH has not received wide attention.
Does reduced breathing reserve (≤30% predicted) predict mortality in patients with Eisenmenger physiology and idiopathic PAH?
Cohort (n=100)
No
Does reduced breathing reserve (≤30% predicted) predict mortality in patients with Eisenmenger physiology and idiopathic PAH?
Hazard Ratio: 3.4 (95% CI 1.1–11.4)
Absolute Event Rate: 48% vs 72%
p-value: p=0.045
A breathing reserve ≤30% at peak exercise is a significant predictor of 10-year mortality in patients with Eisenmenger physiology, but not in those with idiopathic PAH.
Impaired ventilatory responses during exercise significantly contribute to breathlessness in patients with pulmonary arterial hypertension (PAH). Breathing reserve (BR) at peak exercise during cardiopulmonary exercise testing (CPET), a measure of the reserve in the ventilatory capacity, and as a PAH prognostic marker has not received wide attention. We assessed the prognostic value of a reduced BR (≤30% predicted) on survival in patients with two forms of PAH: congenital heart disease-associated PAH and Eisenmenger physiology (EIS) and idiopathic PAH (IPAH). Propensity score matched cohorts of 50 EIS and 50 IPAH patients who underwent CPET in our institution were included. Overall transplant-free survival at 5 and 10 years was assessed. Twenty-five (50.0%) EIS and 15 (33.3%) IPAH patients had a BR ≤ 30% at peak exercise (p = 0.047). Independent predictors of a BR ≤ 30% across all patients included cardiothoracic ratio on chest radiograph (HR 2.2, 95% CI 1.6-3.0, p = 0.01) and moderate to severe restriction on resting spirometry (HR 1.9, 95% CI 1.1-2.8, p = 0.03). A BR ≤ 30% was associated with a significantly higher risk of mortality in the EIS group at 10 years follow-up (HR 3.4, 95% CI 1.1 to 11.4, p = 0.045). Neither a BR ≤ 30% or >30% offered prognostic discrimination in IPAH. In summary, a BR >30% at peak exercise is associated with better survival in patients with EIS. Lung parenchymal restriction inferred from larger cardiothoracic ratios may contribute to reduced BR along with increased ventilatory drive.
No takes yet. Share an insight, caveat, or question.
Samaranayake et al. (2022) conducted a cohort in Eisenmenger syndrome and idiopathic pulmonary arterial hypertension (n=100). Breathing reserve ≤30% at peak exercise vs. Breathing reserve >30% at peak exercise was evaluated on 10-year transplant-free survival (HR 3.4, 95% CI 1.1-11.4, p=0.045). A breathing reserve ≤30% at peak exercise was associated with a significantly higher risk of mortality in patients with Eisenmenger syndrome at 10 years follow-up (HR 3.4).
Synapse has enriched 5 closely related papers on similar clinical questions. Consider them for comparative context: