title: Cardiopulmonary reserve as determined by cardiopulmonary exercise testing correlates with length of stay and predicts complications after radical cystectomy.
abstract: OBJECTIVE
  To investigate whether poor preoperative cardiopulmonary reserve and comorbid state dictate high-risk status and can predict complications in patients undergoing radical cystectomy (RC).
  
  
  METHODS
  In all, 105 consecutive patients with transitional cell carcinoma (TCC; stage T1-T3) undergoing robot-assisted (38 patients) or open (67) RC in a single UK centre underwent preoperative cardiopulmonary exercise testing (CPET). Prospective primary outcome variables were all-cause complications and postoperative length of stay (LOS). Binary logistic regression analysis identified potential predictive factor(s) and the predictive accuracy of CPET for all-cause complications was examined using receiver operator characteristic (ROC) curve analysis. Correlations analysis employed Spearman's rank correlation and group comparison, the Mann-Whitney U-test and Fisher's exact test. Any relationships were confirmed using the Mantel-Haenszel common odds ratio estimate, Kaplan-Meier analysis and the chi-squared test.
  
  
  RESULTS
  The anaerobic threshold (AT) was negatively (r = -206, P = 0.035), and the ventilatory equivalent for carbon dioxide (VE/VCO₂) positively (r = 0.324, P = 0.001) correlated with complications and LOS. Logistic regression analysis identified low AT (<11 mL/kg/min), high VE/VC0₂ (≥33) and hypertension as significant factors, such that, in their presence patients were 5.55-times more likely to have complications at 90 days postoperatively [P = 0.001, 95% confidence interval (CI) 2.2-13.9]. ROC analysis showed a high significance (area under the curve 0.78, 95% CI 0.69-0.87; P < 0.001). In addition, based on CPET criteria >50% of patients presenting for RC had significant heart failure, whereas preoperatively only very few (2%) had this diagnosis. Analysis using the Mann-Whitney test showed that a VE/VCO₂ ≥33 was the most significant determinant of LOS (P = 0.004). Kaplan-Meier analysis showed that patients in this group had an additional median LOS of 4 days (P = 0.008). Finally, patients with an American Society of Anesthesiologists grade of 3 (ASA 3) and those on long-term β-blocker therapy were found to be at particular risk of myocardial infarction (MI) and death after RC with odds ratios of 4.0 (95% CI 1.05-15.2; P = 0.042) and 6.3 (95% CI 1.60-24.8; P = 0.008).
  
  
  CONCLUSIONS
  Patients with poor cardiopulmonary reserve and hypertension are at higher risk of postoperative complications and have increased LOS after RC. Heart failure is known to be a significant determinant of perioperative death and is significantly under diagnosed in this patient group.
authors.affiliation: Department of Anaesthesia, North Bristol NHS Trust, Bristol, UK.
authors.forename: Stephen
authors.initials: S
authors.lastname: Tolchard
authors.forename: Johanna
authors.initials: J
authors.lastname: Angell
authors.forename: Mark
authors.initials: M
authors.lastname: Pyke
authors.forename: Simon
authors.initials: S
authors.lastname: Lewis
authors.forename: Nicholas
authors.initials: N
authors.lastname: Dodds
authors.forename: Alia
authors.initials: A
authors.lastname: Darweish
authors.forename: Paul
authors.initials: P
authors.lastname: White
authors.forename: David
authors.initials: D
authors.lastname: Gillatt
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015308:Anaerobic Threshold / Q000502:physiology*; D015653:Cystectomy / Q000009:adverse effects / Q000379:methods* / Q000401:mortality; D005080:Exercise Test; D005260:Female; D006801:Humans; D053208:Kaplan-Meier Estimate; D007902:Length of Stay; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D011183:Postoperative Complications / Q000175:diagnosis / Q000209:etiology; D011237:Predictive Value of Tests; D011300:Preoperative Care; D011446:Prospective Studies; D012372:ROC Curve; D001749:Urinary Bladder Neoplasms / Q000503:physiopathology* / Q000601:surgery*
keywords: anaerobic threshold; cardiopulmonary exercise testing; postoperative complications; radical cystectomy