Objective: This study aimed to define the relationship between cardiorespiratory fitness and age in the context of postsurgery mortality and morbidity in older people.
Background: Postsurgery mortality and morbidity increase with age. Cardiorespiratory fitness also declines with age, and the independent and linked associations between cardiorespiratory fitness and age on postsurgical mortality and morbidity remain to be determined.
Methods: An unselected consecutive group of 389 adults with a mean age of 66 years (range 26-86 years) underwent cardiorespiratory exercise testing before major hepatobiliary surgery at a single center. Mortality and critical care unit and hospital lengths of stay were collected from patient records. Primary outcomes were in-hospital all-cause mortality after surgery and hospital and critical care lengths of stay.
Results: Anaerobic threshold was the most significant independent predictor for postoperative mortality (P = 0.003; β = -0.657 and odds ratio = 0.52) in 18 of 389 (4.6%) patients who died during their in-hospital stay. Age was not a significant predictor in this model. Older people with normal cardiorespiratory fitness spent the same number of days in the hospital or critical care unit as younger people with similar cardiorespiratory fitness (13 vs 12; P = 0.08 and 1 vs 1; P = 0.103). Patients older than 75 years with low cardiorespiratory fitness spent a median of 11 days longer in hospital (23 vs 12; P < 0.0001) and 2 days longer in critical care (2.9 vs 0.9; P < 0.0001) when compared with patients with adequate cardiorespiratory fitness.
Conclusions: Cardiorespiratory fitness is an independent predictor of mortality and length of hospital stay and provides significantly more accurate prognostic information than age alone. Clinicians should consider both the prognostic value of cardiorespiratory testing and techniques to preserve cardiorespiratory function before elective surgery in older people.