Phillips, A.

Abstract Rationale: Cardiopulmonary exercise testing is a unique tool for simultaneously assessing cardiopulmonary and metabolic responses at peak exercise, making it invaluable for diagnosing unexplained dyspnea and fatigue, common issues in cardiovascular and pulmonary clinics. However, its use is often limited by complex guidelines, restricted lab access, technical demands, and high costs. The Veterans Specific Activity Questionnaire (VSAQ), developed by Meyers et al., offers a practical way to estimate metabolic equivalents and maximum oxygen consumption to assess exercise capacity. While primarily validated in a male population, the VSAQ lacks sufficient research in diverse ethnic and gender groups. Broader validation could enhance personalized cardiopulmonary testing, support equitable healthcare resource allocation, and help lower costs. Methods: In this prospective observational study, participants were included if they were 18 years or older and capable of completing a cardiopulmonary exercise test. Participants were excluded if they had known abnormal breathing patterns at baseline and if they had any contraindication for cardiopulmonary exercise and pulmonary function testing. A total of 17 patients without known cardiopulmonary disease provided informed consent and completed the brief self-administered VSAQ following the cardiopulmonary exercise test. The VSAQ was used to estimate maximal exercise capacity in metabolic equivalents, which was then compared to the actual maximal exercise capacity achieved on a bike ergometer, as recorded in the electronic medical records. Results: A linear regression analysis indicated a marginal association between VSAQ results (METS) and CPET METS, accounting for 22.2% of the variance in CPET METS (p=0.056). This finding suggests a potential, though not statistically significant, positive relationship between VSAQ METS scores and CPET MET. A linear regression analysis indicated a marginal association between VSAQ calculated Peak VO₂ and observed CPET Peak VO₂ (o₂/kg/min), explaining 21.6% of the variance in CPET Peak VO₂ (p=0.060). This suggests a potential positive relationship between VSAQ calculated Peak VO₂ and CPET Peak VO₂, though the association did not reach statistical significance. Conclusion: In this preliminary sample of patients without known cardiopulmonary disease, the VSAQ demonstrated accuracy in predicting maximum oxygen consumption at peak exercise. With further validation and larger sample size, the VSAQ could become a valuable adjunctive tool for assessing patients with unexplained dyspnea and fatigue, supporting more efficient diagnostic evaluations. Additionally, the VSAQ may serve as a practical follow-up measure to track clinical improvement after therapeutic interventions in this specific population.