Cardiorespiratory fitness is impaired and predicts mid-term postoperative survival in patients with abdominal aortic aneurysm disease: Cardiorespiratory fitness predicts postoperative survival

Preoperative cardiopulmonary exercise testing (PCPET) is a standard assessment used for the assessment of cardiorespiratory fitness (CRF) and risk stratification. However, to what extent CRF is impaired in patients undergoing surgical repair of abdominal aortic aneurysm (AAA) disease and corresponding implications for postoperative outcome requires further investigation. We measured CRF during an incremental exercise test to exhaustion using online respiratory gas analysis in patients with AAA disease (n = 124, aged 72 ± 7 years) and healthy sedentary controls (n = 104, aged 70 ± 7 years). Postoperative survival was examined for association with CRF and threshold values calculated for independent predictors of mortality. Patients who underwent PCPET prior to surgical repair had lower CRF [age-adjusted mean difference of 12.5 mL O2.kg-1.min-1 for peak oxygen uptake (V̇O2 peak), P < 0.001 vs. controls]. Following multivariable analysis, both V̇O2 peak and the ventilatory equivalent for carbon dioxide at anaerobic threshold (V̇E/V̇CO2-AT) were independent predictors of mid-term postoperative survival (2 years). Hazard ratios of 5.27 (95% confidence interval (CI) 1.62 to 17.14, P = 0.006) and 3.26 (95% CI 1.00 - 10.59, P = 0.049) were observed for V̇O2 peak < 13.1 mL O2.kg-1.min-1 and V̇E/V̇CO2-AT ≥ 34 respectively. Thus, CRF is lower in patients with AAA and those with a V̇O2 peak < 13.1 mL O2.kg-1.min-1 and V̇E/V̇CO2-AT ≥ 34 are associated with a markedly increased risk of post-operative mortality. Collectively, our findings demonstrate that CRF can predict mid-term postoperative survival in AAA patients which may help direct care provision.