Tag Archive for: cardiopulmonary exercise testing


Article of the Week: Using cardiopulmonary reserve to predict complications following radical cystectomy

Every week the Editor-in-Chief selects the Article of the Week from the current issue of BJUI. The abstract is reproduced below and you can click on the button to read the full article, which is freely available to all readers for at least 30 days from the time of this post.

In addition to the article itself, there is an accompanying editorial written by a prominent member of the urological community. This blog is intended to provoke comment and discussion and we invite you to use the comment tools at the bottom of each post to join the conversation.

If you only have time to read one article this week, it should be this one.


Cardiopulmonary Reserve as Determined by Cardiopulmonary Exercise Testing Correlates with Length of Stay and Predicts Complications following Radical Cystectomy


Stephen Tolchard, Johanna Angell, Mark Pyke, Simon Lewis, Nicholas DoddsAlia 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



To investigate whether poor preoperative cardiopulmonary reserve and comorbid state dictate high-risk status and can predict complications in patients undergoing radical cystectomy (RC).


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.


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).


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.

Editorial: Cardiopulmonary exercise testing: fortune-teller or guardian angel?

In this month’s issue of BJUI, Tolchard et al. [1] describe their experience with the use of cardiopulmonary exercise testing (CPET) in patients undergoing radical cystectomy. In particular, they assess the value of cardiopulmonary reserve in predicting complications and the length of stay in hospital after surgery.

The origin of CPET is in non-surgical specialties for the further investigation of patients with cardiac failure or unexplained breathlessness [2], but it subsequently gained utility in surgical fields, including the preoperative assessment of patients undergoing cardiac surgery [3].

In more recent times, it has been increasingly adopted within ‘high-risk’ preoperative assessment clinics for those patients undergoing a wide range of major elective, non-cardiac surgery; however, this enthusiastic uptake has often preceded more formal validation of the test’s ability to perform reliably in these new patient groups and their associated surgical procedures. The Bristol group [1] has therefore prospectively studied the role of CPET in 105 patients undergoing either robot-assisted or open radical cystectomy for TCC, using all-cause complications and length of stay as the primary outcome variables.

The researchers found that anaerobic threshold (AT), ventilatory equivalent for carbon dioxide (VE/VCO2) and hypertension were independent predictors of postoperative complications. Using the criteria chosen by Older et al. [4] of an AT ≤ 11 mL/kg/min and or VE/VECO2 ≥ 33, it was possible to define a high- and low-risk group. The high-risk group were 5.5 times more likely to experience a complication at 90 days compared with the low-risk group and, notably, all deaths and myocardial infarctions occurred in the high-risk group. As expected, they found that complications prolonged length of stay. Additionally, falling AT and or rising VE/VECO2 also correlated with increasing length of stay. Their study therefore suggests that CPET may have a role in the preoperative risk stratification of patients undergoing radical cystectomy by an open or robot-assisted approach.

The authors acknowledge that the cohort size is small and from a single institution, thereby necessitating further validation work across multiple centres, as well as subgroup analysis of differing surgical approaches. Interestingly, their study excluded patients who had received neoadjuvant chemotherapy; for many UK cancer centres, this would exclude ∼70% of patients undergoing radical cystectomy. It would clearly be important in future studies to understand how CPET metrics perform in this wider cohort, where anaemia and impaired performance status are known to be more common.

On the assumption that further studies may validate the use of CPET as a preoperative risk-stratifying tool, the pertinent question is how do we translate this research finding into patient benefit? Interventions such as preoperative patient optimization, pre-habilitation exercise regimes or the planned escalation of postoperative care may confer benefits but, as yet, we do not know if they attenuate the increased risk of complications or the prolonged inpatient stay.

As further evaluation of CPET takes place, we should remain cautious about its use as a ‘rule-out’ investigation in those patients otherwise considered eligible for radical surgical treatment. To date, there have been no formal evaluations of patients’ quality of life or end-of-life care in ‘non-operated’ cases. Poor local control of pelvic malignancy remains one of the most challenging aspects of care for uro-oncologists and, at times, it may even outweigh the impact of postoperative surgical complications. Due consideration must be given to this aspect when advising individual patients about the predicted risks and benefits of therapeutic treatment options. The decision to operate should clearly be informed by the preoperative assessment, but it is imperative that it continues to involve the patient’s wider multidisciplinary team, whose responsibility it will be to provide lifelong care.

In conclusion, CPET offers an interesting opportunity to identify those patients at greatest risk of adverse outcomes after radical cystectomy; however, the full benefits will not be realized if it is simply the ‘bearer of bad news’. The key to its success will be the identification of modifiable behaviours, by both the patient and the clinical team, that lead to improved patient-related outcomes. These outcomes should not be restricted to overall or cancer-specific survival but also measures of return to good health and prior performance status. Such longer-term outcome data may then help us to more accurately delineate the point at which the risks of a surgical treatment can be confidently predicted to outweigh the alternative of non-operative care for individual patients.

Read the full article
John S. McGrath
Royal Devon and Exeter NHS Trust, Exeter, UK





2 Szlachcic J, Massie BM, Kramer BL, Topic N, Tubau J. Correlates and prognostic implication of exercise capacity in chronic congestive heart failure. Am J Cardiol 1985; 55: 103742


3 Mancini DM, Eisen H, Kussmaul W, Mull R, Edmunds LH Jr, Wilson JRValue of peak exercise oxygen consumption for optimal timing of cardiac transplantation in ambulatory patients with heart failure. Circulation 1991;83: 77886



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