title: Psoas Muscle Area and Length of Stay in Older Adults Undergoing Cardiac Operations.
abstract: BACKGROUND
  Frailty assessment can help predict which older adults will experience adverse events after cardiac surgical procedures. Low muscle mass is a core component of frailty that is suboptimally captured by self-reported weight loss; refined measures using computed tomographic (CT) images have emerged and are predictive of outcomes in noncardiac surgical procedures. The objective of this study was to evaluate the association between CT muscle area and length of stay (LOS) after cardiac surgical procedures.
  
  
  METHODS
  Frail patients who had a perioperative abdominal or thoracic CT scan were identified. The CT scans were analyzed to measure cross-sectional lean muscle area at the L4 vertebra (psoas muscle area [PMA], lumbar muscle area [LMA]) and the T4 vertebra (thoracic muscle area [TMA]). The associations of PMA, LMA, and TMA with frailty markers and postoperative LOS were investigated.
  
  
  RESULTS
  Eighty-two patients were included; the mean age was 69.2 ± 9.97 years. Low muscle area was correlated with lower handgrip strength and short physical performance battery (SPPB) scores indicative of physical frailty. Postoperative LOS was correlated with PMA (R = -0.47, p = 0.004), LMA (R = -0.41, p = 0.01), and TMA (R = -0.29, p = 0.03). After adjustment for the predicted risk of prolonged LOS, age, sex, and body surface area, PMA remained significantly associated with LOS (β = -2.35, 95% CI -4.48 to -0.22). The combination of low PMA and handgrip strength, indicative of sarcopenia, yielded the greatest incremental value in predicting LOS.
  
  
  CONCLUSIONS
  Low PMA is a marker of physical frailty associated with increased LOS in older adults undergoing cardiac surgical procedures. Further research is necessary to validate PMA as a prognostic marker and therapeutic target in this vulnerable population.
authors.affiliation: Department of Medicine, McGill University, Montreal, Quebec, Canada.
authors.forename: Jesse
authors.initials: J
authors.lastname: Zuckerman
authors.affiliation: Department of Medicine, McGill University, Montreal, Quebec, Canada.
authors.forename: Matthew
authors.initials: M
authors.lastname: Ades
authors.affiliation: Department of Medicine, McGill University, Montreal, Quebec, Canada.
authors.forename: Louis
authors.initials: L
authors.lastname: Mullie
authors.affiliation: Centre for Clinical Epidemiology, Lady Davis Institute, Jewish General Hospital, Montreal, Quebec, Canada.
authors.forename: Amanda
authors.initials: A
authors.lastname: Trnkus
authors.affiliation: Division of Cardiac Surgery, Jewish General Hospital, McGill University, Montreal, Quebec, Canada.
authors.forename: Jean-Francois
authors.initials: JF
authors.lastname: Morin
authors.affiliation: Division of Cardiac Surgery, Jewish General Hospital, McGill University, Montreal, Quebec, Canada.
authors.forename: Yves
authors.initials: Y
authors.lastname: Langlois
authors.affiliation: Division of Cardiac Surgery, Jewish General Hospital, McGill University, Montreal, Quebec, Canada.
authors.forename: Felix
authors.initials: F
authors.lastname: Ma
authors.affiliation: Department of Radiology, Jewish General Hospital, McGill University, Montreal, Quebec, Canada.
authors.forename: Mark
authors.initials: M
authors.lastname: Levental
authors.affiliation: Division of Geriatric Medicine, McGill University Health Center, Montreal, Quebec, Canada.
authors.forename: José A
authors.initials: JA
authors.lastname: Morais
authors.affiliation: Department of Medicine, McGill University, Montreal, Quebec, Canada; Centre for Clinical Epidemiology, Lady Davis Institute, Jewish General Hospital, Montreal, Quebec, Canada; Division of Cardiology, Jewish General Hospital, McGill University, Montreal, Quebec, Canada. Electronic address: jonathan.afilalo@mcgill.ca.
authors.forename: Jonathan
authors.initials: J
authors.lastname: Afilalo
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D001830:Body Surface Area; D058385:Cardiac Valve Annuloplasty; D015331:Cohort Studies; D001026:Coronary Artery Bypass; D005260:Female; D016330:Frail Elderly; D018737:Hand Strength / Q000502:physiology; D019918:Heart Valve Prosthesis Implantation; D006801:Humans; D007902:Length of Stay / Q000706:statistics & numerical data*; D008297:Male; D008875:Middle Aged; D053580:Muscle Strength / Q000502:physiology; D009133:Muscular Atrophy / Q000000981:diagnostic imaging* / Q000473:pathology; D011183:Postoperative Complications / Q000209:etiology*; D011237:Predictive Value of Tests; D011446:Prospective Studies; D016658:Psoas Muscles / Q000000981:diagnostic imaging* / Q000473:pathology; D018570:Risk Assessment / Q000706:statistics & numerical data; D013223:Statistics as Topic; D014057:Tomography, X-Ray Computed