title: Submaximal exercise testing predicts perioperative hospitalization after aortic aneurysm repair.
abstract: BACKGROUND
  Aortic aneurysm repair is a high-risk surgical procedure. Patients are often elderly, with multiple comorbidities that predispose them to perioperative morbidity. Use of endovascular aneurysm repair (EVAR) has increased due to reduced early perioperative risk. This study assessed whether preoperative cardiopulmonary exercise testing (CPET) could be used to predict morbidity and hospital length of stay (LOS) after aortic aneurysm repair.
  
  
  METHODS
  A total of 185 patients underwent surgical repair (84 open repairs, 101 EVAR) and had adequate determination of a submaximal CPET parameter (anaerobic threshold).
  
  
  RESULTS
  Patient comorbidities and cardiorespiratory fitness, derived from CPET, were similar between surgical procedures. Patients undergoing EVAR had fewer complications (10% vs 32%; P<.0001) and shorter mean (standard deviation [SD]) hospital LOS of 5.7 (9.3) days vs 14.4 (10.9) days compared with open repair (P<.0001). The hospital LOS was significantly increased in patients with one or more complications in both groups compared with those with no complications. In the open repair group, the level of fitness, as defined by anaerobic threshold, was an independent predictor of postoperative morbidity and hospital LOS. When the optimal anaerobic threshold (10 mL/min/kg) derived from receiver operator curve analysis was used as a cutoff value, unfit patients stayed significantly longer than fit patients in critical care (mean, 6.4 [SD, 6.9] days vs 2.4 [SD, 2.9] days; P=.002) and in the hospital (mean, 23.1 [SD, 14.8] days vs 11.0 [SD, 6.1] days; P<.0001). In contrast, fitness in the EVAR group was not predictive of postoperative morbidity but did have predictive value for hospital LOS.
  
  
  CONCLUSIONS
  Cardiorespiratory fitness holds significant clinical value before aortic aneurysm repair in predicting postsurgical complications and duration of critical care and hospital LOS. Preoperative measurement of fitness could then direct clinical management with regard to operative choice, postoperative resource allocation, and informed patient decision making.
authors.affiliation: Department of Perioperative and Critical Care Medicine, the Freeman Hospital, and the Institute of Cellular Medicine, Biomedical Research Centre for Ageing and Age Related Diseases, Newcastle University, Newcastle upon Tyne, United Kingdom. james.prentis@nuth.nhs.uk
authors.forename: James M
authors.initials: JM
authors.lastname: Prentis
authors.forename: Michael I
authors.initials: MI
authors.lastname: Trenell
authors.forename: Dave J
authors.initials: DJ
authors.lastname: Jones
authors.forename: Tim
authors.initials: T
authors.lastname: Lees
authors.forename: Mike
authors.initials: M
authors.lastname: Clarke
authors.forename: Chris P
authors.initials: CP
authors.lastname: Snowden
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D015308:Anaerobic Threshold / Q000502:physiology; D017544:Aortic Aneurysm, Abdominal / Q000150:complications / Q000503:physiopathology* / Q000601:surgery*; D019917:Blood Vessel Prosthesis Implantation / Q000009:adverse effects*; D015331:Cohort Studies; D017558:Elective Surgical Procedures / Q000009:adverse effects; D057510:Endovascular Procedures / Q000009:adverse effects*; D005080:Exercise Test; D017079:Exercise Tolerance / Q000502:physiology; D005260:Female; D006801:Humans; D007902:Length of Stay; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D016896:Treatment Outcome