Cardiopulmonary reserve as determined by cardiopulmonary exercise testing correlates with length of stay and predicts complications after radical cystectomy Stephen Tolchard, Johanna Angell, Mark Pyke, Simon Lewis, Nicholas Dodds, Alia Darweish, Paul White* and David Gillatt† Departments of Anaesthesia and †Surgery, North Bristol NHS Trust, and *Applied Statistics Group, Department of Mathematics and Statistics, University of the West of England, Bristol, UK

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).

Patients and 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 (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).

Conclusion 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.

Keywords cardiopulmonary exercise testing, radical cystectomy, postoperative complications, anaerobic threshold

RC (RARC) and 3.8–5.0% for open RC (ORC); however, mortality appears to be reducing having approached 13% as recently as two decades ago [1–5]. Significant complications occur in ≈30% of cases, with 3–16% requiring re-operation [1,4]. Interestingly, mortality and morbidity is independent of age [5], with selected populations of octogenarians © 2014 The Authors BJU International © 2014 BJU International | doi:10.1111/bju.12895 Published by John Wiley & Sons Ltd. www.bjui.org

Cardiopulmonary reserve influences LOS and complications after RC

faring as well as younger patients in selected series. Bladder cancer is associated with smoking and industrial exposure to carcinogens and therefore the patient population are at higher risk of cardiovascular disease. The morbidity and mortality associated with RC reflects the high-risk group who undergo the procedure. Whilst improved surgery, safer anaesthesia and minimally invasive surgery are changing the outcomes [1–5], RC is still associated with considerable risks. Recent guidelines [6] from the Royal College of Surgeons and the Department of Health recommend that patients undergoing major surgery should be risk stratified to determine the required level of perioperative care. Thus, patients at significant risk of death after major surgery should have active consultant-led care and be admitted to critical care postoperatively. Such guidelines raise obvious questions about the assessment of perioperative risk and how best to achieve it. Currently the American College of Cardiologists/American Heart Association (ACC/AHA) recommend the use of the Duke Activity Scale Index (DASI) to estimate physiological reserve [7]. However, the DASI and the incremental shuttle walk test, whilst showing good correlation with each other, fail to discriminate between potentially high- and low-risk patients [8]. Identifying those at high risk is important to inform the risk/benefit discussion with patients and to guide perioperative care [6–8]. Patients at particular risk of perioperative death seem to be those with heart failure [9,10]. Major surgery is associated with a systemic inflammatory response, which markedly increases perioperative oxygen demand [11]. Myocardial infarction (MI) and death are thought to arise from the inability of patients with low cardiopulmonary reserve to meet this additional demand [12]. Cardiopulmonary exercise testing (CPET) is emerging as a useful tool in the determination of perioperative risk. Patients with a poor CPET result are at much higher risk of perioperative cardiac morbidity and death [11–19]. Measuring oxygen uptake (VO2) during exercise, and the point at which aerobic respiration is supplemented by anaerobic respiration to produce energy, the anaerobic threshold (AT) [20], appears to be important. Thus, patients with a low AT (

Cardiopulmonary reserve as determined by cardiopulmonary exercise testing correlates with length of stay and predicts complications after radical cystectomy.

To investigate whether poor preoperative cardiopulmonary reserve and comorbid state dictate high-risk status and can predict complications in patients...
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