Exercise blood pressure relative to fitness: pragmatic clinical potential

This commentary refers to ‘Exercise blood pressure relative to fitness and cardiovascular outcomes: the EXERTION study’, by M.G. Schultz et al., https://doi.org/10.1093/eurheartj/ehaf1082 and the discussion piece ‘Methodological challenges in integrating exercise blood pressure and cardiorespiratory fitness for cardiovascular risk assessment: insights from the EXERTION Study’, by J. Nan et al., https://doi.org/10.1093/eurheartj/ehag443. This commentary refers to ‘Exercise blood pressure relative to fitness and cardiovascular outcomes: the EXERTION study’, by M.G. Schultz et al., https://doi.org/10.1093/eurheartj/ehaf1082 and the discussion piece ‘Reassessing exercise blood pressure relative to fitness: a nuanced marker for cardiovascular risk’, by Y. Zhong et al., https://doi.org/10.1093/eurheartj/ehag442. We thank Zhong et al.,1 and Nan et al.,2 for their respective discussion forum letters. We appreciate their interest in the EXERTION study, and for the opportunity to further clarify some of the potential limitations of our data. We agree with Zhong et al.,1 that cardiopulmonary exercise testing (CPET) with measurement of expired gases (to determine VO2Peak) provides the gold-standard assessment of fitness. However, CPET is not routinely undertaken in cardiovascular/coronary risk assessment, and our intent was to explore development of a pragmatic, widely applicable marker based on routinely available data from standard clinical exercise stress testing (hence the use of ubiquitously available METs to estimate fitness). At the request of reviewers of the original manuscript, we provided an estimated VO2peak (where 1 MET approximated 3.5 mL.kg.min−1) and included this in the analysis. As is also acknowledged in the article, whether indexing exercise systolic blood pressure (SBP) to a directly measured VO2Peak would yield different risk discrimination is unknown. Therefore, validation across alternative fitness markers is warranted.