The cardiopulmonary exercise test grey zone; optimising fitness stratification by application of critical difference

G.A. |Rose, R.G. Davies, Gareth Davison, R.A. Adams, I. M. Williams, M.H. Lewis

Research output: Contribution to journalArticle

6 Citations (Scopus)

Abstract

Background: Cardiorespiratory fitness can inform patient care, although to what extent natural variation in CRF influences clinical practice remains to be established. We calculated natural variation for cardiopulmonary exercise test (CPET) metrics, which may have implications for fitness stratification. Methods: In a two-armed experiment, critical difference comprising analytical imprecision and biological variation was calculated for cardiorespiratory fitness and thus defined the magnitude of change required to claim a clinically meaningful change. This metric was retrospectively applied to 213 patients scheduled for colorectal surgery. These patients underwent CPET and the potential for misclassification of fitness was calculated. We created a model with boundaries inclusive of natural variation [critical difference applied to oxygen uptake at anaerobic threshold (V_O2-AT): 11 ml O2 kg1 min1, peak oxygen uptake (V_O2 peak): 16 ml O2 kg1 min1, and ventilatory equivalent for carbon dioxide at AT (VE/VCO2-AT): 36]. Results: The critical difference for V_O2-AT, V_O2 peak, and V_ E/V_CO2-AT was 19%, 13%, and 10%, respectively, resulting in false negative and false positive rates of up to 28% and 32% for unfit patients. Our model identified boundaries for unfit and fit patients: AT <9.2 and 13.6 ml O2 kg1 min1, V_O2 peak <14.2 and 18.3 ml kg1 min1, V_ E/V_CO2-AT 40.1 and <32.7, between which an area of indeterminate-fitness was established. With natural variation considered, up to 60% of patients presented with indeterminate-fitness. Conclusions: These findings support a reappraisal of current clinical interpretation of cardiorespiratory fitness highlighting the potential for incorrect fitness stratification when natural variation is not accounted for.
LanguageEnglish
Pages1187-1194
Number of pages8
JournalBritish Journal of Anaesthesia
Volume120
Issue number6
Early online date8 Apr 2018
DOIs
Publication statusPublished - 30 Jun 2018

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Exercise Test
Oxygen
Anaerobic Threshold
Colorectal Surgery
Carbon Dioxide
Patient Care
Cardiorespiratory Fitness

Keywords

  • anaerobic threshold
  • cardiopulmonary exercise test
  • risk assessment

Cite this

|Rose, G.A. ; Davies, R.G. ; Davison, Gareth ; Adams, R.A. ; Williams, I. M. ; Lewis, M.H. / The cardiopulmonary exercise test grey zone; optimising fitness stratification by application of critical difference. In: British Journal of Anaesthesia. 2018 ; Vol. 120, No. 6. pp. 1187-1194.
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title = "The cardiopulmonary exercise test grey zone; optimising fitness stratification by application of critical difference",
abstract = "Background: Cardiorespiratory fitness can inform patient care, although to what extent natural variation in CRF influences clinical practice remains to be established. We calculated natural variation for cardiopulmonary exercise test (CPET) metrics, which may have implications for fitness stratification. Methods: In a two-armed experiment, critical difference comprising analytical imprecision and biological variation was calculated for cardiorespiratory fitness and thus defined the magnitude of change required to claim a clinically meaningful change. This metric was retrospectively applied to 213 patients scheduled for colorectal surgery. These patients underwent CPET and the potential for misclassification of fitness was calculated. We created a model with boundaries inclusive of natural variation [critical difference applied to oxygen uptake at anaerobic threshold (V_O2-AT): 11 ml O2 kg1 min1, peak oxygen uptake (V_O2 peak): 16 ml O2 kg1 min1, and ventilatory equivalent for carbon dioxide at AT (VE/VCO2-AT): 36]. Results: The critical difference for V_O2-AT, V_O2 peak, and V_ E/V_CO2-AT was 19{\%}, 13{\%}, and 10{\%}, respectively, resulting in false negative and false positive rates of up to 28{\%} and 32{\%} for unfit patients. Our model identified boundaries for unfit and fit patients: AT <9.2 and 13.6 ml O2 kg1 min1, V_O2 peak <14.2 and 18.3 ml kg1 min1, V_ E/V_CO2-AT 40.1 and <32.7, between which an area of indeterminate-fitness was established. With natural variation considered, up to 60{\%} of patients presented with indeterminate-fitness. Conclusions: These findings support a reappraisal of current clinical interpretation of cardiorespiratory fitness highlighting the potential for incorrect fitness stratification when natural variation is not accounted for.",
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author = "G.A. |Rose and R.G. Davies and Gareth Davison and R.A. Adams and Williams, {I. M.} and M.H. Lewis",
note = "1. West MA, Asher R, Browning M, et al. Validation of preoperative cardiopulmonary exercise testing-derived variables to predict in-hospital morbidity after major colorectal surgery. Br J Surg 2016; 103: 744-52 2. Grant SW, Hickey GL, Wisely NA, et al. Cardiopulmonary exercise testing and survival after elective abdominal aortic aneurysm repair. Br J Anaesth 2015; 114: 430-6 3. Carlisle J, Swart M. Mid-term survival after abdominal aortic aneurysm surgery predicted by cardiopulmonary exercise testing. Br J Surg 2007; 94: 966-9 4. Lai CW, Minto G, Challand CP, et al. Patients’ inability to perform a preoperative cardiopulmonary exercise test or demonstrate an anaerobic threshold is associated with inferior outcomes after major colorectal surgery. Br J Anaesth 2013; 111: 607-11 5. Prentis JM, Trenell MI, Jones DJ, Lees T, Clarke M, Snowden CP. Submaximal exercise testing predicts perioperative hospitalization after aortic aneurysm repair. J Vasc Surg 2012; 56: 1564-70 6. Snowden CP, Prentis J, Jacques B, et al. Cardiorespiratory fitness predicts mortality and hospital length of stay after major elective surgery in older people. Ann Surg 2013; 257: 999-1004 7. West MA, Parry MG, Lythgoe D, et al. Cardiopulmonary exercise testing for the prediction of morbidity risk after rectal cancer surgery. Br J Surg 2014; 101: 1166-72 8. Ross R, Blair SN, Arena R, et al. Importance of assessing cardiorespiratory fitness in clinical practice: a case for fitness as a clinical vital sign: a scientific statement from the American Heart Association. Circulation 2016; 134: e653-99 9. Older R, Smith R, Courtney B, Hone R. Preoperative evaluation of cardiac failure and ischemia in elderly patients by cardiopulmonary exercise testing. Chest 1993; 104: 701-4 10. Junejo MA, Mason JM, Sheen AJ, et al. Cardiopulmonary exercise testing for preoperative risk assessment before hepatic resection. Br J Surg 2012; 99: 1097-104 11. Hartley RA, Pichel AC, Grant SW, et al. Preoperative cardiopulmonary exercise testing and risk of early mortality following abdominal aortic aneurysm repair. Br J Surg 2012; 99: 1539-46 12. Moran J, Wilson F, Guinan E, McCormick P, Hussey J, Moriarty J. Role of cardiopulmonary exercise testing as a risk-assessment method in patients undergoing intra abdominal surgery: a systematic review. Br J Anaesth 2016; 116: 177-91 13. Fraser CG, Fogarty Y. Interpreting laboratory results. BMJ 1989; 298: 1659-60 14. Davison GW, Ashton T, McEneny J, Young IS, Davies B, Bailey DM. Critical difference applied to exercise-induced oxidative stress: the dilemma of distinguishing biological from statistical change. J Physiol Biochem 2012; 68: 377-84 15. Bailey DM, Evans TG, Gower Thomas K. Intervisceral artery origins in patients with abdominal aortic aneurysmal disease; evidence for systemic vascular remodelling. Exp Physiol 2016; 101: 1143-53 16. Williams JR. The Declaration of Helsinki and public health. Bull World Health Organ 2008; 86: 650-2 17. Wasserman K. Principles of exercise testing and interpretation: including pathophysiology and clinical applications. 5th ed. London: Wolters Kluwer/Lippincott Williams & Wilkins; 2012 18. Beaver WL, Wassermen K, Whipp BJ. A new method for detecting anaerobic threshold by gas exchange. J Appl Physiol 1986; 60: 2020-7 19. American Thoracic Society. ATS/ACCP statement on cardiopulmonary exercise testing. Am J Respir Crit Care Med 2003; 167: 211-77 20. West MA, Loughney L, Barben CP, et al. The effects of neoadjuvant chemoradiotherapy on physical fitness and morbidity in rectal cancer surgery patients. Eur J Surg Oncol 2014; 40: 1421-8 21. Wilson RJ, Davies S, Yates D, Redman J, Stone M. Impaired functional capacity is associated with all-cause mortality after major elective intra-abdominal surgery. Br J Anaesth 2010; 105: 297-303 22. Guazzi M, Arena R, Halle M, Piepoli MF, Myers J, Lavie CJ. 2016 focused update: clinical recommendations for cardiopulmonary exercise testing data assessment in specific patient populations. Circulation 2016; 133: e694-711 23. Junejo MA, Mason JM, Sheen AJ, et al. Cardiopulmonary exercise testing for preoperative risk assessment before pancreaticoduodenectomy for cancer. Ann Surg Oncol 2014; 21: 1929-36 24. Epstein SK, Freeman RB, Khayat A, Unterborn JN, Pratt DS, Kaplan MM. Aerobic capacity is associated with 100-day outcome after hepatic transplantation. Liver Transpl 2004; 10: 418-24 25. Altman DG. Statistics and ethics in medical research: III How large a sample? BMJ 1980; 281: 1336-8 26. Arena R, Myers J, Williams MA, et al. Assessment of functional capacity in clinical and research settings: a scientific statement from the American Heart Association committee on exercise, rehabilitation, and prevention of the council on clinical cardiology and the council on cardiovascular nursing. Circulation 2007; 116: 329e43 27. Swart M, Carlisle JB, Goddard J. Using predicted 30 day mortality to plan postoperative colorectal surgery care: a cohort study. Br J Anaesth 2017; 118: 100-4 28. Grocott MPW. Improving outcomes after surgery. BMJ 2009; 339: b5173 29. Owens MW, Kinasewitz GT, Strain DS. Evaluating the effects of chronic therapy in patients with irreversible airflow obstruction. Am Rev Respir Dis 1986; 134: 935-7 30. Janicki JS, Gupta S, Ferris ST, McElroy PA. Long-term reproducibility of respiratory gas exchange measurements during exercise in patients with stable cardiac failure. Chest 1990; 97: 12-7 31. Elborn JS, Stanford CF, Nicholls DP. Reproducibility of cardiopulmonary parameters during exercise in patients with chronic cardiac failure. The need for a preliminary test. Eur Heart J 1990; 11: 75-81 32. Keteyian SJ, Brawner CA, Ehrman JK, Ivanhoe R, Boehmer JP, Abraham WT. Reproducibility of peak oxygen uptake and other cardiopulmonary exercise parameters: implications for clinical trials and clinical practice. Chest 2010; 138: 950-5 33. Kothmann E, Danjoux G, Owen SJ, Parry A, Turley AJ, Batterham AM. Reliability of the anaerobic threshold in cardiopulmonary exercise testing of patients with abdominal aortic aneurysms. Anaesthesia 2009; 64: 9-13 34. Huszczuk A, Whipp B, Wasserman K. A respiratory gas exchange simulator for routine calibration in metabolic studies. Eur Respir J 1990; 3: 465-8 35. Kothmann E, Batterham AM, Owen SJ, et al. Effect of short-term exercise training on aerobic fitness in patients with abdominal aortic aneurysms: a pilot study. Br J Anaesth 2009; 103: 505-10",
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}

The cardiopulmonary exercise test grey zone; optimising fitness stratification by application of critical difference. / |Rose, G.A.; Davies, R.G.; Davison, Gareth; Adams, R.A. ; Williams, I. M.; Lewis, M.H.

In: British Journal of Anaesthesia, Vol. 120, No. 6, 30.06.2018, p. 1187-1194.

Research output: Contribution to journalArticle

TY - JOUR

T1 - The cardiopulmonary exercise test grey zone; optimising fitness stratification by application of critical difference

AU - |Rose, G.A.

AU - Davies, R.G.

AU - Davison, Gareth

AU - Adams, R.A.

AU - Williams, I. M.

AU - Lewis, M.H.

N1 - 1. West MA, Asher R, Browning M, et al. Validation of preoperative cardiopulmonary exercise testing-derived variables to predict in-hospital morbidity after major colorectal surgery. Br J Surg 2016; 103: 744-52 2. Grant SW, Hickey GL, Wisely NA, et al. Cardiopulmonary exercise testing and survival after elective abdominal aortic aneurysm repair. Br J Anaesth 2015; 114: 430-6 3. Carlisle J, Swart M. Mid-term survival after abdominal aortic aneurysm surgery predicted by cardiopulmonary exercise testing. Br J Surg 2007; 94: 966-9 4. Lai CW, Minto G, Challand CP, et al. Patients’ inability to perform a preoperative cardiopulmonary exercise test or demonstrate an anaerobic threshold is associated with inferior outcomes after major colorectal surgery. Br J Anaesth 2013; 111: 607-11 5. Prentis JM, Trenell MI, Jones DJ, Lees T, Clarke M, Snowden CP. Submaximal exercise testing predicts perioperative hospitalization after aortic aneurysm repair. J Vasc Surg 2012; 56: 1564-70 6. Snowden CP, Prentis J, Jacques B, et al. Cardiorespiratory fitness predicts mortality and hospital length of stay after major elective surgery in older people. Ann Surg 2013; 257: 999-1004 7. West MA, Parry MG, Lythgoe D, et al. Cardiopulmonary exercise testing for the prediction of morbidity risk after rectal cancer surgery. Br J Surg 2014; 101: 1166-72 8. Ross R, Blair SN, Arena R, et al. Importance of assessing cardiorespiratory fitness in clinical practice: a case for fitness as a clinical vital sign: a scientific statement from the American Heart Association. Circulation 2016; 134: e653-99 9. Older R, Smith R, Courtney B, Hone R. Preoperative evaluation of cardiac failure and ischemia in elderly patients by cardiopulmonary exercise testing. Chest 1993; 104: 701-4 10. Junejo MA, Mason JM, Sheen AJ, et al. Cardiopulmonary exercise testing for preoperative risk assessment before hepatic resection. Br J Surg 2012; 99: 1097-104 11. Hartley RA, Pichel AC, Grant SW, et al. Preoperative cardiopulmonary exercise testing and risk of early mortality following abdominal aortic aneurysm repair. Br J Surg 2012; 99: 1539-46 12. Moran J, Wilson F, Guinan E, McCormick P, Hussey J, Moriarty J. Role of cardiopulmonary exercise testing as a risk-assessment method in patients undergoing intra abdominal surgery: a systematic review. Br J Anaesth 2016; 116: 177-91 13. Fraser CG, Fogarty Y. Interpreting laboratory results. BMJ 1989; 298: 1659-60 14. Davison GW, Ashton T, McEneny J, Young IS, Davies B, Bailey DM. Critical difference applied to exercise-induced oxidative stress: the dilemma of distinguishing biological from statistical change. J Physiol Biochem 2012; 68: 377-84 15. Bailey DM, Evans TG, Gower Thomas K. Intervisceral artery origins in patients with abdominal aortic aneurysmal disease; evidence for systemic vascular remodelling. Exp Physiol 2016; 101: 1143-53 16. Williams JR. The Declaration of Helsinki and public health. Bull World Health Organ 2008; 86: 650-2 17. Wasserman K. Principles of exercise testing and interpretation: including pathophysiology and clinical applications. 5th ed. London: Wolters Kluwer/Lippincott Williams & Wilkins; 2012 18. Beaver WL, Wassermen K, Whipp BJ. A new method for detecting anaerobic threshold by gas exchange. J Appl Physiol 1986; 60: 2020-7 19. American Thoracic Society. ATS/ACCP statement on cardiopulmonary exercise testing. Am J Respir Crit Care Med 2003; 167: 211-77 20. West MA, Loughney L, Barben CP, et al. The effects of neoadjuvant chemoradiotherapy on physical fitness and morbidity in rectal cancer surgery patients. Eur J Surg Oncol 2014; 40: 1421-8 21. Wilson RJ, Davies S, Yates D, Redman J, Stone M. Impaired functional capacity is associated with all-cause mortality after major elective intra-abdominal surgery. Br J Anaesth 2010; 105: 297-303 22. Guazzi M, Arena R, Halle M, Piepoli MF, Myers J, Lavie CJ. 2016 focused update: clinical recommendations for cardiopulmonary exercise testing data assessment in specific patient populations. Circulation 2016; 133: e694-711 23. Junejo MA, Mason JM, Sheen AJ, et al. Cardiopulmonary exercise testing for preoperative risk assessment before pancreaticoduodenectomy for cancer. Ann Surg Oncol 2014; 21: 1929-36 24. Epstein SK, Freeman RB, Khayat A, Unterborn JN, Pratt DS, Kaplan MM. Aerobic capacity is associated with 100-day outcome after hepatic transplantation. Liver Transpl 2004; 10: 418-24 25. Altman DG. Statistics and ethics in medical research: III How large a sample? BMJ 1980; 281: 1336-8 26. Arena R, Myers J, Williams MA, et al. Assessment of functional capacity in clinical and research settings: a scientific statement from the American Heart Association committee on exercise, rehabilitation, and prevention of the council on clinical cardiology and the council on cardiovascular nursing. Circulation 2007; 116: 329e43 27. Swart M, Carlisle JB, Goddard J. Using predicted 30 day mortality to plan postoperative colorectal surgery care: a cohort study. Br J Anaesth 2017; 118: 100-4 28. Grocott MPW. Improving outcomes after surgery. BMJ 2009; 339: b5173 29. Owens MW, Kinasewitz GT, Strain DS. Evaluating the effects of chronic therapy in patients with irreversible airflow obstruction. Am Rev Respir Dis 1986; 134: 935-7 30. Janicki JS, Gupta S, Ferris ST, McElroy PA. Long-term reproducibility of respiratory gas exchange measurements during exercise in patients with stable cardiac failure. Chest 1990; 97: 12-7 31. Elborn JS, Stanford CF, Nicholls DP. Reproducibility of cardiopulmonary parameters during exercise in patients with chronic cardiac failure. The need for a preliminary test. Eur Heart J 1990; 11: 75-81 32. Keteyian SJ, Brawner CA, Ehrman JK, Ivanhoe R, Boehmer JP, Abraham WT. Reproducibility of peak oxygen uptake and other cardiopulmonary exercise parameters: implications for clinical trials and clinical practice. Chest 2010; 138: 950-5 33. Kothmann E, Danjoux G, Owen SJ, Parry A, Turley AJ, Batterham AM. Reliability of the anaerobic threshold in cardiopulmonary exercise testing of patients with abdominal aortic aneurysms. Anaesthesia 2009; 64: 9-13 34. Huszczuk A, Whipp B, Wasserman K. A respiratory gas exchange simulator for routine calibration in metabolic studies. Eur Respir J 1990; 3: 465-8 35. Kothmann E, Batterham AM, Owen SJ, et al. Effect of short-term exercise training on aerobic fitness in patients with abdominal aortic aneurysms: a pilot study. Br J Anaesth 2009; 103: 505-10

PY - 2018/6/30

Y1 - 2018/6/30

N2 - Background: Cardiorespiratory fitness can inform patient care, although to what extent natural variation in CRF influences clinical practice remains to be established. We calculated natural variation for cardiopulmonary exercise test (CPET) metrics, which may have implications for fitness stratification. Methods: In a two-armed experiment, critical difference comprising analytical imprecision and biological variation was calculated for cardiorespiratory fitness and thus defined the magnitude of change required to claim a clinically meaningful change. This metric was retrospectively applied to 213 patients scheduled for colorectal surgery. These patients underwent CPET and the potential for misclassification of fitness was calculated. We created a model with boundaries inclusive of natural variation [critical difference applied to oxygen uptake at anaerobic threshold (V_O2-AT): 11 ml O2 kg1 min1, peak oxygen uptake (V_O2 peak): 16 ml O2 kg1 min1, and ventilatory equivalent for carbon dioxide at AT (VE/VCO2-AT): 36]. Results: The critical difference for V_O2-AT, V_O2 peak, and V_ E/V_CO2-AT was 19%, 13%, and 10%, respectively, resulting in false negative and false positive rates of up to 28% and 32% for unfit patients. Our model identified boundaries for unfit and fit patients: AT <9.2 and 13.6 ml O2 kg1 min1, V_O2 peak <14.2 and 18.3 ml kg1 min1, V_ E/V_CO2-AT 40.1 and <32.7, between which an area of indeterminate-fitness was established. With natural variation considered, up to 60% of patients presented with indeterminate-fitness. Conclusions: These findings support a reappraisal of current clinical interpretation of cardiorespiratory fitness highlighting the potential for incorrect fitness stratification when natural variation is not accounted for.

AB - Background: Cardiorespiratory fitness can inform patient care, although to what extent natural variation in CRF influences clinical practice remains to be established. We calculated natural variation for cardiopulmonary exercise test (CPET) metrics, which may have implications for fitness stratification. Methods: In a two-armed experiment, critical difference comprising analytical imprecision and biological variation was calculated for cardiorespiratory fitness and thus defined the magnitude of change required to claim a clinically meaningful change. This metric was retrospectively applied to 213 patients scheduled for colorectal surgery. These patients underwent CPET and the potential for misclassification of fitness was calculated. We created a model with boundaries inclusive of natural variation [critical difference applied to oxygen uptake at anaerobic threshold (V_O2-AT): 11 ml O2 kg1 min1, peak oxygen uptake (V_O2 peak): 16 ml O2 kg1 min1, and ventilatory equivalent for carbon dioxide at AT (VE/VCO2-AT): 36]. Results: The critical difference for V_O2-AT, V_O2 peak, and V_ E/V_CO2-AT was 19%, 13%, and 10%, respectively, resulting in false negative and false positive rates of up to 28% and 32% for unfit patients. Our model identified boundaries for unfit and fit patients: AT <9.2 and 13.6 ml O2 kg1 min1, V_O2 peak <14.2 and 18.3 ml kg1 min1, V_ E/V_CO2-AT 40.1 and <32.7, between which an area of indeterminate-fitness was established. With natural variation considered, up to 60% of patients presented with indeterminate-fitness. Conclusions: These findings support a reappraisal of current clinical interpretation of cardiorespiratory fitness highlighting the potential for incorrect fitness stratification when natural variation is not accounted for.

KW - anaerobic threshold

KW - cardiopulmonary exercise test

KW - risk assessment

UR - https://pure.southwales.ac.uk/en/publications/the-cardiopulmonary-exercise-test-grey-zone-optimising-fitness-stratification-by-application-of-critical-difference(5d172bb4-edcb-4d4d-8e60-14484ffae48c).html

U2 - 10.1016/j.bja.2018.02.062

DO - 10.1016/j.bja.2018.02.062

M3 - Article

VL - 120

SP - 1187

EP - 1194

JO - British Journal of Anaesthesia

T2 - British Journal of Anaesthesia

JF - British Journal of Anaesthesia

SN - 0007-0912

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ER -