Asset Publisher


print Print Back Back

Cardiopulmonary Exercise Stress Test (CPET/CPX)

Policy Number: MP-198


Latest Review Date: November 2023

Category:  Medicine                                                              


Cardiopulmonary Exercise Testing (CPET) may be considered medically necessary when basic clinical data such as a history and physical exam, CXR, pulmonary function studies and resting EKG have failed to provide sufficient diagnosis for the following indications:


  1. Evaluation of exercise capacity and response to therapy in patients with congestive heart failure.
  2. Differentiation of cardiac versus pulmonary limitations as a cause of exercise-induced dyspnea or impaired exercise capacity when traditional testing is inconclusive or non-diagnostic.
  3. Preoperative evaluation for lung cancer resection surgery or lung volume reduction surgery, when pulmonary function studies alone are unable to accurately assess moderate to high-risk patients.  (Low-risk patients can be evaluated accurately with routine pulmonary function test, such as FEV1, diffusing capacity of the lung for CO).

CPET is considered investigational when used to evaluate conditions not listed above.  This would include but not be limited to the following:

  • Chronic fatigue syndrome
  • Fibromyalgia
  • Exercise intolerance
  • Pacemaker regulation
  • Obesity
  • Diabetes
  • Hyperlipidemia
  • Hypertension
  • Routine pre-operative assessment
  • Exercise prescription
  • Asthma


Cardiopulmonary exercise testing (CPET) provides a global assessment of the integrative exercise responses involving the pulmonary, cardiovascular, hematopoietic, neurophysiological, and skeletal muscle systems.

Cardiopulmonary exercise testing involves measuring oxygen uptake (VO2), carbon dioxide output (VCO2), minute ventilation (VE) and other variables in addition to a 12-lead EKG, blood pressure monitoring and pulse oximetry (SpO2).  These measurements are obtained during a maximal symptom-limited incremental exercise test.  In certain clinical situations, an additional measurement of arterial blood gases may be used to assess pulmonary gas exchange.

Two modes of exercise are commonly used in CPET:  treadmill and cycle ergometer.  The motor-driven treadmill increases exercise stress through a combination of speed and elevation or grade increases.  There are several incremental protocols, i.e., Bruce, used for this testing.  The protocol should be selected based on the objectives of the test and the patient’s clinical condition.  The treadmill test has several advantages over the cycle ergometry.  Most individuals are more familiar with walking as an activity than cycling.  In addition, maximal oxygen uptake is reported to be 5-10% higher on the treadmill than a cycle ergometer. The cycle ergometer is less likely to introduce artifact into the measurements.  The rate at which the external work is performed is also easily quantified.  There are two types of cycle ergometers:  mechanically braked and electrically braked.  The mechanically braked ergometers generally do not offer precise work rate settings and require the individual to pedal at a fixed cadence to keep the work rate constant.  The electrically braked ergometer provides direct quantification of the work performed and can be computer controlled to change work rate incrementally or continuously. Both cycle and treadmill testing uses a progressive incremental exercise pattern which lasts for approximately 12 minutes or until symptoms occur. 

CPET is a safe procedure with the risk of death for the patients between 2-5 per 100,000 exercise tests performed.  For all tests, attention to patient safety is of the utmost importance.  Only qualified personnel should supervise testing. 

A number of variables are typically measured or derived during the CPET.  The chart listed below shows the components and whether the components are invasive or non-invasive.



Invasive (ABGs)

External work



Metabolic gas exchange




HR, ECG, BP, O2 pulse



VE, VT, fR


Pulmonary gas exchange


PaO2, SaO2, P(A-a)O2, VD/VT



PH, PaCO2, standard HCO3-


Dyspnea, fatigue, chest pain


Definition of abbreviations:  ABGs = Arterial blood gases; AT = anaerobic threshold; BP = blood pressure; ECG = electrocardiogram; fR = respiratory frequency; HR = heart rate; P(A-a)O2 = alveolar-arterial difference for oxygen pressure; PaCO2 = arterial carbon dioxide pressure; PaO2 = arterial oxygen pressure PETCO2 = end-tidal PCO2; PETO2 = end-tidal PO2; RER = respiratory exchange ratio; SaO2 = arterial oxygen saturation; SpO2 = arterial oxygen saturation as indicated by pulse oximetry; VCO2 = carbon dioxide output; VE = minute ventilation; VD/VT = ratio of physiologic dead space to tidal volume; VO2 = oxygen uptake; VT = tidal volume; WR = work rate.


A literature search was performed through November 22, 2023.

Summary of Evidence

For those who receive cardiopulmonary exercise testing (CPET) because basic clinical data have failed to provide sufficient diagnosis for patients being considered for heart transplants, to differentiate between cardiac and pulmonary limitations for exercise induced dyspnea when traditional testing is inconclusive/non-diagnostic, or for preoperative evaluation for lung cancer resection surgery or lung volume reduction surgery, the evidence includes a vast amount of literature. For individuals with unexplained dyspnea and for when initial test results are non-diagnostic, CPET may be a useful tool in identifying the true underlying cause of the dyspnea.  CPET may efficiently direct further diagnostic testing to target the suspected organ involved or may limit subsequent testing depending upon results of the CPET.  In patients with heart failure who are being considered for heart transplantation, there is strong evidence to support the value of CPET in the assessment of exercise capacity and the response efficacy of current therapy of patients with heart failure who are being considered for heart transplantation.  Additionally, individuals for preoperative evaluation for lung cancer resection surgery or lung volume reduction surgery, additional diagnostic modalities including CPET may be particularly useful in predicting postoperative pulmonary complications. The evidence is sufficient to determine the effects of this technology on health outcomes.

For those who receive CPET for other indications, there is insufficient evidence that CPET should be used as a screening tool or first line test. Further studies are needed to determine the effects of this technology on health outcomes.

American Heart Association

In July 2010, the American Heart Association (AHA) published the “Clinician’s Guide to Cardiopulmonary Exercise Testing in Adults”.  The AHA states the following in their summary of Key Points of this guide:

  • These guides are based primarily on expert consensus interpretation of published data as available as there are no randomized trials to address diagnostic and prognostic applications of CPX.
  • CPX systems must be properly maintained and calibrated to ensure that high-quality data are provided.
  • CPX test supervision, monitoring, and interpretation should be performed by competent personnel as recommended in established exercise testing guidelines.
  • Integration of CPX test data with exercise-ECG test data provides optimal comprehensive use of CPX. 
  • CPX in clinical populations has been well studied and appears most useful in the evaluation of patients with heart failure and those with unexplained dyspnea.  Other uses include the assessment of patients with mitochondrial myopathies, development of the exercise prescription in patients with cardiovascular disease or stroke, and the assessment of disability in patients with cardiac or pulmonary disease. 
  • Emerging and less well studied applications of CPX include the evaluation of patients with adult congenital heart disease, pulmonary hypertension, cardiac arrhythmias and pacemakers, and ischemic heart disease and the pre-operative assessment of patients undergoing pulmonary resection or bariatric surgery.
  • Assessment of CPX data should be done to ensure its validity before a final report is generated.
  • Future studies are needed to rigorously evaluate whether CPX provides additional discriminatory diagnostic and prognostic value over and above that provided by standard exercise tests and other clinical variables. 

American College of Cardiology and American Heart Association

In 2002, the ACC and AHA updated their 1997 guideline for exercise testing. They recommended the following:

Evaluation of exercise capacity and response to therapy in patients with heart failure who are being considered for heart transplantation

Class I

Assistance in the differentiation of cardiac versus pulmonary limitations as a cause of exercise induced dyspnea or impaired exercise capacity when the cuase is uncertain.

Class I

Evaluation of exercise capacity when indicated for medical reasons in patients in whom the estimates of exercise capacity from exercise test time or work rate are unreliable.

Class IIa

Evaluation of the patient’s response to specific therapeutic interventions in which improvement of exercise tolerance is an important goal or end point.

Class IIb

Determination of the intensity for exercise training as part of comprehensive cardiac rehabilitation.

Class IIb


European Association for Cardiovascular Prevention and Rehabilitation (EACPR) and American Heart Association (AHA)

In 2012 (focus update 2016), the EACPR published clinical recommendations for CPET data assessment in specific patient populations. They state that the use of CPX is “well established for patients with systolic HF, undergoing a pre-transplant assessment, and individuals with unexplained exertional dyspnea.”  All other diagnoses were reported to be rapidly expanding and emerging.


Metabolic GXT, Met-Test, exercise testing with ventilatory gas analysis, cardiopulmonary exercise testing, CPX, CPET


Not applicable


Coverage is subject to member’s specific benefits.  Group specific policy will supersede this policy when applicable.

ITS: Home Policy provisions apply

FEP contracts:  Special benefit consideration may apply.  Refer to member’s benefit plan.


CPT coding:        


Cardiovascular stress test using maximal or submaximal treadmill or bicycle exercise, continuous electrocardiographic monitoring, and/or pharmacological stress; with supervision, interpretation and report


In addition, several of the following codes may be used to report the pulmonary variables of this test.



Spirometry, including graphic record, total and timed vital capacity, expiratory flow rate measurement(s), with or without maximal voluntary ventilation


Prolonged postexposure evaluation of bronchospasm with multiple spirometric determinations after antigen, cold air, methacholine or other chemical agent, with subsequent spirometrics


Vital capacity, total (separate procedure)


Maximum breathing capacity, maximal voluntary ventilation


Functional residual capacity or residual volume: helium method, nitrogen open circuit method, or other method


Determination of airway closing volume, single breath tests


Respiratory flow volume loop


Cardiopulmonary exercise stress testing; complex including measurements of minute ventilation, co2 production, o2 uptake, and electrocardiographic recordings.


Oxygen uptake, expired gas analysis; including co2 output, percentage oxygen extracted


Carbon monoxide diffusing capacity (e.g., single breath, steady state)


  1. American College of Cardiology and American Heart Association. ACC/AHA 2002 Guideline Update for Exercise Testing. J Am Coll Eardiol. 2002 Oct 16;40(8):1531-40.
  2. American Thoracic Society.  ATS/ACCP statement on cardiopulmonary exercise testing, American Journal of Respiratory and Critical Care Medicine 2003, Vol. 167, pp. 211-277.
  3. American Thoracic Society.  Erratum:  ATS/ACCP statement on cardiopulmonary exercise testing, American Journal of Respiratory and Critical Care Medicine 2003, Vol. 167, pp. 1451-1452.
  4. Balady GJ, Arena R, Sietsema, et al.  Clinician’s guide to cardiopulmonary exercise testing in adults:  A scientific statement from the American Heart Association.  Circulation 2010; 122: 191-225.
  5. Belardinelli Romualdo, Lacalaprice Francesca, Carle Flavia, et al.  Exercise-induced myocardial ischaemia detected by cardiopulmonary exercise testing, European Heart Journal 2003; 24: 1304-1313.
  6. Chaitman Bernard R.  Exercise stress testing, Braunwald:  Heart Disease:  A Textbook of Cardiovascular Medicine, 6th edition, Chapter 6, pp. 129-131.
  7. Fleg Jerome L, Pina Ileana L, Balady Gary J, et al.  Assessment of functional capacity in clinical and research applications:  An advisory from the Committee on Exercise, Rehabilitation, and Prevention, Council on Clinical Cardiology, American Heart Association, Circulation 2000; 102(13): 1591
  8. Fletcher Gerald F, Balady Gary, Froelicher Victor F, et al.  Exercise standards:  A statement for healthcare professionals from the American Heart Association, Circulation 1995; 91(2): 580.
  9. Gibbons Raymond J, Balady Gary J, Bricker J Timothy, et al.  ACC/AHA 2002 guideline update for exercise testing:  A report of the American College of Cardiology/American Heart Association Task Force on practice guidelines (Committee on Exercise Testing), American College of Cardiology Foundation and the American Heart Association, Inc. 2002, or
  10. Guazzi M, Adams V, Conraads V, et al. Clinical Recommendations for Cardiopulmonary Exercise Testing Data Assessment in Specific Patient Populations. Circulation. 2012 Oct 30; 126(18): 2261–2274.
  11. Guazzi M, Arena R, Halle M, et al. 2016 Focused Update: Clinicla Recommendations for Cardiopulmonary exercise testing data assessment in specific patient populations.  Circulation. 2016 May 2; 133(24).
  12. Hone Rodney.  Perioperative evaluation of cardiac failure and ischemia in elderly patients by cardiopulmonary exercise testing, Chest September 1993.
  13. IOM (Institute of Medicine). 2011. Clinical Practice Guidelines We Can Trust. Washington, DC: The National Academies Press.
  14. Malhotra R, Bakken K, D’Elia E, Lewis GD. Cardiopulmonary exercise testing in heart failure. JACC. 2016 Aug; 4(8): 607-16.
  15. Myers J, Gullestad L, Vagelos R, Do D, Bellin D, et al.  Clinical, hemodynamic, and cardiopulmonary exercise test determinants of survival in patients referred for evaluation of heart failure, Ann Intern Med 1998; 129: 286-293.
  16. Older P, Smith R, Courtney P, and Hone R.  Preoperative evaluation of cardiac failure and ischemia in elderly patients by cardiopulmonary exercise testing, Chest, September 1993; 104(3): 701-4 (Abstract).
  17. Pina Ileana L, Balady Gary J, et al.  Guidelines for clinical exercise testing laboratories:  A statement for healthcare professionals from the Committee on Exercise and Cardiac Rehabilitation, American Heart Association, Circulation 1995; 91(3): 912-921.
  18. Singh Vibhuti.  The role of gas analysis with exercise testing, Primary Care, March 2001, Vol. 28, No. 1, pp. 159-178.
  19. Stelken AM, Younis LT, Jennison SH, Miller DD, et al.  Prognostic value of cardiopulmonary exercise testing using percent achieved of predicted peak oxygen uptake for patients with ischemic and dilated cardiomyopathy, J Am College of Cardiology 1996; 27: 345-352.
  20. Sun Xing-Guo, Hansen James E, Garatachea Nuria, et al.  Ventilatory efficiency during exercise in healthy subjects, American Journal of Respiratory and Critical Care Medicine 2002, Vol. 166, pp. 1443-1448.
  21. United States Preventive Services Task Force (USPSTF).  Recommendation statement:  Screening for coronary heart disease,
  22. Wasserman Karlman.  Impact of integrative cardiopulmonary exercise testing on clinical decision making, Chest; April 1991.
  23. Wasserman Karlman.  Preoperative evaluation of cardiovascular reserve in the elderly (Editorial), Chest, September 1993.
  24. Weisman IM.  Cardiopulmonary exercise testing in the preoperative assessment for lung resection surgery, Semin thorac Cardiovasc Surg, April 2001; 13(2): 116-25.
  25. Weisman Idelle M and Zeballos R Jorge.  Clinical exercise testing, Clinics in Chest Medicine December 2001, Vol. 22, No. 4, pp. 679-701, viii.


Medical Review Committee, July 2004

Medical Policy Group, August 2004 (3)

Medical Review Committee, August 2004

Medical Policy Administration Committee, September 2004

Available for comment September 8-October 22, 2004

Medical Policy Group, August 2006 (1)

Medical Policy Group, August 2008 (1)

Medical Policy Group, August 2010 (1) Key Points updated, no coverage change

Medical Policy Group, August 2011 (1): Active policy but no longer scheduled for literature updates.

Medical Policy Group, December 2011(3); 2012 Coding Update – Code 94240 & 94720 delete 1/1/12

Medical Policy Group, December 2012(3); 2013 Coding Update – Verbiage update to Code 93015 – removed “physician”.

Medical Policy Group, December 2017: 2018 Coding Update.  Updated verbiage for revised code 94621.

Medical Policy Group, February 2020 (4): Updates to Policy, Description, Key Points, and References. Opened coverage for all CHF, not just those being considered for heart transplant.

Medical Policy Administrative Committee : February 2020

Available for comment: February 14, 2020 through March 30, 2020

Medical Policy Group, January 2021 (4): Reviewed by consensus. No change to policy statements.

Medical Policy Group, January 2022 (4): Reviewed by consensus. References added. No new published peer-reviewed literature available that would alter the coverage statement in this policy.

Medical Policy Group, December 2022 (4): Reviewed by consensus.  Key Points updated and References added.  Removed policy statements effective for dates of service prior to February 14, 2020.

Medical Policy Group, November 2023 (4): Reviewed by consensus.  Updates to Benefit Application. No new published peer-reviewed literature available that would alter the coverage statement in this policy.

This medical policy is not an authorization, certification, explanation of benefits, or a contract. Eligibility and benefits are determined on a case-by-case basis according to the terms of the member’s plan in effect as of the date services are rendered. All medical policies are based on (i) research of current medical literature and (ii) review of common medical practices in the treatment and diagnosis of disease as of the date hereof. Physicians and other providers are solely responsible for all aspects of medical care and treatment, including the type, quality, and levels of care and treatment.


This policy is intended to be used for adjudication of claims (including pre-admission certification, pre-determinations, and pre-procedure review) in Blue Cross and Blue Shield’s administration of plan contracts.

The plan does not approve or deny procedures, services, testing, or equipment for our members. Our decisions concern coverage only. The decision of whether or not to have a certain test, treatment or procedure is one made between the physician and his/her patient. The plan administers benefits based on the member’s contract and corporate medical policies. Physicians should always exercise their best medical judgment in providing the care they feel is most appropriate for their patients. Needed care should not be delayed or refused because of a coverage determination.

As a general rule, benefits are payable under health plans only in cases of medical necessity and only if services or supplies are not investigational, provided the customer group contracts have such coverage.

The following Association Technology Evaluation Criteria must be met for a service/supply to be considered for coverage:

1. The technology must have final approval from the appropriate government regulatory bodies;

2. The scientific evidence must permit conclusions concerning the effect of the technology on health outcomes;

3. The technology must improve the net health outcome;

4. The technology must be as beneficial as any established alternatives;

5. The improvement must be attainable outside the investigational setting.


Medical Necessity means that health care services (e.g., procedures, treatments, supplies, devices, equipment, facilities or drugs) that a physician, exercising prudent clinical judgment, would provide to a patient for the purpose of preventing, evaluating, diagnosing or treating an illness, injury or disease or its symptoms, and that are:

1. In accordance with generally accepted standards of medical practice; and

2. Clinically appropriate in terms of type, frequency, extent, site and duration and considered effective for the patient’s illness, injury or disease; and

3. Not primarily for the convenience of the patient, physician or other health care provider; and

4. Not more costly than an alternative service or sequence of services at least as likely to produce equivalent therapeutic or diagnostic results as to the diagnosis or treatment of that patient’s illness, injury or disease.