Fitness plus American Society of Anesthesiologists grade improve outcome prediction after endovascular aneurysm repair

Abstract

Although the American Society of Anesthesiologists (ASA) grade was established for statistical purposes, it is often used prognostically. However, older patients undergoing elective surgery are typically ASA III, which limits patient stratification. We look at the prognostic effect on early complications and survival of using ASA and self-reported physical fitness to stratify patients undergoing endovascular repair of abdominal aortic aneurysms. Data were extracted from a trial database. All patients were assigned a fitness level (A (fit) or B (unfit)) based on their self-reported ability to walk briskly for 1 km or climb two flights of stairs. Fitness was used to stratify ASA III patients, with fitter patients assigned ASA IIIA and less fit patients ASA IIIB. Outcomes assessed included survival, reinterventions, endoleak, all early and late complications and early operative complications. A combined ASA/fitness scale (II, IIIA, IIIB and IV) correlated with 1- and 3-year survival (1-year P = 0.001, 3-year P = 0.001) and early and late complications (P = 0.001 and P = 0.05). On its own, ASA predicted early complications (P = 0.0004) and survival (1-year P = 0.01, 3-year P = 0.01). Fitness alone was predictive for survival (1-year P = 0.001, 3-year P = 0.001) and late complications (P = 0.009). This study shows that even a superficial assessment of fitness is reflected in surgical outcomes, with fitter ASA III patients showing survival patterns similar to ASA II patients. Physicians should be alert to differences in fitness between patients in the ASA III group, despite similarities based on preexisting severe systemic disease.