BACKGROUND: Rapid triaging, as in the current COVID-19 pandemic, focuses on age TRANS and pre-existing medical conditions. In contrast, preoperative assessments use cardiopulmonary exercise testing (CPET) to categorise patients to higher and lower risk independent of diagnostic labels. Since CPET is not feasible in population-based settings, our aims included evaluation of a triage/screening tool for cardiorespiratory risk. METHODS: CPET-derived anaerobic thresholds were evaluated retrospectively in 26 patients with pulmonary arteriovenous malformations HP arteriovenous malformations MESHD (AVMs) who represent a challenging group to risk-categorise. Pulmonary AVM-induced hypoxaemia secondary to intrapulmonary right-to-left shunts HP right-to-left shunts HP, anaemia from underlying hereditary haemorrhagic telangiectasia HP and metabolic equivalents derived from the 13-point Veterans Specific Activity Questionnaire (VSAQ) were evaluated as part of routine clinical care. Pre-planned analyses evaluated associations and modelling of the anaerobic threshold and patient-specific variables. RESULTS: In the 26 patients ( aged TRANS 21-77, median 57 years), anaerobic threshold ranged from 7.6-24.5 (median 12.35) ml.min-1kg-1 and placed more than half of the patients (15, 57.7%) in the >11 ml.min-1kg-1 category suggested as lower-risk for intra-abdominal surgeries. Neither age TRANS nor baseline SpO2 predicted anaerobic threshold, or lower/higher risk categories, either alone or in multivariate analyses, despite baseline oxygen saturation (SpO2) ranging from 79 to 99 (median 92)%, haemoglobin from 108 to 183 (median 156)g.L-1. However, lower haemoglobin, and particularly, arterial oxygen content and oxygen pulse were associated with increased cardiorespiratory risk: Modelling a haemoglobin increase of 25g.L-1 placed a further 7/26 (26.9%) patients in a lower risk category. For patients completing the VSAQ, derived metabolic equivalents were strongly associated with anaerobic threshold enabling risk evaluations through a simple questionnaire. CONCLUSIONS: Baseline exercise tolerance may override age TRANS and diagnostic labels in triage settings. These data support approaches to risk reduction by aerobic conditioning and attention to anaemia. The VSAQ is suggested as a rapid screening tool for cardiorespiratory risk assessment to implement during triage/screening.