Delayed VO2 recovery is associated with reduced transplant free survival in heart failure

Abstract

Introduction Impaired peak oxygen uptake (VO2) is an established prognostic marker in heart failure (HF) and utilised to support decision for cardiac transplantation1. VO2 recovery delay (VO2RD) post cardiopulmonary exercise testing (CPET) has been investigated to further understand physiologic demand and prognosis in HF patients2.

Aim Determine the incidence of VO2RD in heart failure patients undergoing CPET for investigation of HF and the relationship between VO2RD and 12‐month outcomes.

Method A retrospective analysis of the results of CPETs performed in 52 patients with confirmed heart failure performed between July 2015 and June 2017. VO2RD, defined as time for VO2 to decline below peak VO2 following cessation of exercise and peak VO2 overshoot (VO2OS), where VO2 increases during the recovery phase, were used as measures for oxygen recovery kinetics. All patients were reviewed 12 months after their CPET.

Results 12 patients had a normal VO2 recovery post CPET while 40 patients showed a delayed VO2 recovery. 38% of patients (n = 20) died or underwent cardiac transplantation at review. 85% of these patients experienced delayed VO2 recovery compared to 72% of those that remained alive and transplant‐free.

Conclusion Delayed post CPET VO2 recovery with VO2RD or VO2OS is easily identifiable and may prove useful for further stratification of heart failure. Further data analysis will focus on VO2RD as a predictor of cardiac limitation to exercise and prognosis in heart failure.