Abstract

Exercise capacity (EC) is an important predictor of survival in the general population as well as in individuals with cardiopulmonary disease. Despite its relevance, considering percent-predicted workload (%pWL) given by current equations may overestimate EC in older adults. Therefore, to improve the reporting of EC in clinical practice, our main objective was to develop workload reference equations (pWL) that better reflect the relation between workload and age. Using the Fitness Registry and the Importance of Exercise National Database (FRIEND), we analyzed a reference group of 6,966 apparently healthy participants and 1,060 participants with HF who underwent graded treadmill cardiopulmonary exercise testing. For the first group, the mean age was 44 years [18-79]; 56.5% of individuals were male and 15.4% had obesity. Peak VO2 was 11.6 ± 3.0 METs in males and 8.5±2.4 METs in females. After partition analysis, we first developed sex-specific pWL equations to allow comparisons to a healthy weight reference. For males, pWL (METs)?=?14.1 - 0.9?×?10-3?×?age2 and for female 11.5 - 0.87?×?10-3?×?age2. We used those equations as denominators of %pWL and, based on their distribution, we determined thresholds for EC classification, with average EC defined by the range corresponding to 85-115%pWL. Compared to %pWL using current equations, the new equations yielded better-calibrated %pWL across different age ranges. We also derived body mass index-adjusted pWL equations that better assessed EC in individuals with HF. In conclusion, the novel pWL equations have the potential to impact the report of EC in practice.

View details for DOI 10.1016/j.amjcard.2024.01.022

View details for PubMedID 38301753