SRS93 - Novel use of arm ergometry Cardiopulmonary Exercise Testing for non-elective patients with chronic limb-threatening ischaemia: a feasibility trial

Background Chronic limb threatening ischaemia (CLTI) represents the most advanced stage of peripheral arterial disease and is associated with high morbidity and mortality. Preoperative risk stratification is critical but challenging due to patient co-morbidity and emergent presentation. Cardiopulmonary exercise testing (CPET) is a gold-standard assessment of cardiorespiratory fitness but traditional modalities are unsuitable for patients with lower limb dysfunction, such as those with CLTI. This study evaluates the feasibility, safety and acceptability of arm crank ergometry CPET (CPETarm) in patients with CLTI. Methods A prospective cohort of 60 patients scheduled for non-elective vascular surgical intervention underwent CPETarm using an incremental ramp protocol. CPET parameters measured included peak VO2, anaerobic threshold (AT), ventilatory equivalent of carbon dioxide at AT (VE/VCO2), peak work, oxygen pulse, maximum heart rate and respiratory exchange ratio (RER). Feasibility outcomes measured included safety, implementation, practicality, and acceptability. Results CPETarm was successfully completed to volitional exhaustion by 95% of participants, with 65% achieving a maximal test (RER > 1.05) and 68% achieving anaerobic threshold. No serious adverse events occurred. The majority (90%) of CPETs were completed within 48 h of a decision to initiate treatment, with no delays to intervention. CPETarm was well tolerated and positively received by patients. Conclusions CPETarm is a feasible, acceptable, and safe tool for preoperative assessment in CLTI patients, offering a promising alternative for risk stratification in individuals unsuitable for traditional testing. Further validation is required to establish modality-specific thresholds and assess prognostic value, potentially improving perioperative decision-making and outcomes in this high-risk cohort.