Clinical utility of ventilatory and gas exchange evaluation during low-intensity exercise for risk stratification and prognostication in pulmonary arterial hypertension

Author(s)

Sayegh, Ana Luiza C. ^{[1, 2]} ; Silva, Bruno Moreira ^[3] ; Ferreira, Eloara V. M. ^[2] ; Ramos, Roberta P. ^[2] ; Fisher, James P. ^[1] ; Nery, Luiz E. ^[2] ; Ota-Arakaki, Jaquelina S. ^[2] ; Oliveira, Rudolf K. F. ^[2]

Affiliation

^[1] Univ Auckland, Dept Physiol, Auckland - New Zealand

^[2] Fed Univ Sao Paulo UNIFESP, Dept Med, Div Resp Dis, Rua Napoleao de Barros 771, 3 Andar, BR-04024002 Sao Paulo, SP - Brazil

^[3] Fed Univ Sao Paulo UNIFESP, Dept Physiol, Sao Paulo, SP - Brazil

• Document type: Journal article
• Source: Respirology; v. 26, n. 3 OCT 2020.
• Web of Science Citations: 0

Abstract

Background and objective Peak oxygen consumption (pVO(2)), determined from CPET, provides a valuable indication of PAH severity and patient prognosis. However, CPET is often contraindicated in severe PAH and frequently terminated prior to achievement of a sufficient exercise effort. We sought to determine whether in PAH low-intensity {[}i.e. freewheeling exercise (FW)] exercise reveals abnormal V-E/VCO2 and PETCO2 responses that are associated with pVO(2) and serve as indices of PAH risk stratification and mortality. Methods Retrospective analysis of CPET from 97 PAH patients and 20 age-matched controls was undertaken. FW V-E/VCO2 and PETCO2 were correlated with pVO(2)% age-predicted. Prognostication analysis was conducted using pVO(2) > 65% age-predicted, as known to represent a low mortality risk. Primary outcome was mortality from any cause. Results FW PETCO2 was correlated with pVO(2) (P < 0.0001; r = 0.52), while FW V-E/VCO2 was not (P = 0.13; r = -0.16). ROC curve analyses showed that FW PETCO2 (AUC = 0.659), but not FW V-E/VCO2 (AUC = 0.587), provided predictive information identifying pVO(2) > 65% age-predicted (best cut-off value of 28 mm Hg). By Cox analysis, FW PETCO2 < 28 mm Hg remained a predictor of mortality after adjusting for age and PAH aetiology (HR: 2.360, 95% CI: 1.144-4.866, P = 0.020). Conclusion Low PETCO2 during FW is associated with reduced pVO(2) in PAH and provides predictive information for PAH risk stratification and prognostication. (AU)

• FAPESP's process: 14/24294-6 - Tonic contribution of the peripheral chemoreflex to the vagal control of the heart at rest and recovery from exercise in patients with chronic heart failure
• Grantee: Bruno Moreira Silva
• Support Opportunities: Regular Research Grants