Introduction Several cardiopulmonary exercise testing (CPET) variables have been shown to predict prognosis in pulmonary hypertension (PH).¹ Recently published data suggests that novel variables such as oxygen uptake efficiency slope (OUES), i.e. the relationship between VO₂ and log-transformed ventilation² and heart rate recovery (HRR), the rate of decline of heart rate at one minute after an incremental CPET, have been shown to predict survival in a cohort of PH patients.

We aimed to study the prognostic significance of the rate of recovery of VO₂ after incremental CPET alongside HRR and OUES in a large cohort of patients with precapillary PH. We hypothesised that a slower VO₂ recovery would be associated with poorer survival and that we could confirm that lower HRR and OUES are significantly associated with a worse outcome.

Method Retrospective analysis was undertaken of data from108 incident patients who underwent CPET at the time of diagnosis of Group I or IV PH. Univariate Cox proportional hazard analyses were undertaken to assess the prognostic significance of the variables considered and the results are shown in Table 1.

Results [Table 1]

Conclusions The degree of VO₂ recovery at 120 seconds after incremental CPET is predictive of survival in this relatively large group of patients with precapillary PH. We have also confirmed the findings seen in another centre of a significant influence of heart rate recovery and OUES on survival. Further work should focus on whether these variables provide additional prognostic information over their more traditionally studied counterparts.

References

1. Johnson MJ, Thomson SD. The role of exercise testing in the modern management of pulmonary arterial hypertension Diseases 2014;2(2):120–47

2. Ramos, et al. Exercise oxygen uptake efficiency slope independently predicts poor outcome in pulmonary arterial hypertension. Eur Respir J 2014;43(5):1510–12