Research Article| Volume 58, P134-138, March 2023

Independent predictors and equation of six-minute walk test in post-cardiac surgery

Published:December 09, 2022DOI:


      • This is the first study to compare 6MWD between at hospital discharge and the 4–6-week follow-up after cardiac surgery.
      • 6MWD at discharge, regular exercise, age, gender, and NYHA classification were found to independently predict 6MWD at 4–6 weeks after hospital discharge.
      • The equation generated by multivariate analysis to predict 6MWD recovery after hospital discharge.



      The six-minute walk test (6MWT) has been used to evaluate postsurgical recovery in cardiac patients. No previous study has compared the 6MWT at follow-up with a baseline, or evaluated the long-term effects of cardiac surgery on post-discharge 6MWT


      To identify the factors independently associated with 6MWD, and to develop an equation to predict 6MWT at the 4–6-week follow-up after post-cardiac surgery hospital discharge.


      Patient data of elective coronary artery bypass graft (CABG) or non-CABG surgery patients were retrospectively collected. The 6MWT was performed at hospital discharge and at the 4–6-week follow-up. Available demographic and clinical data of patients were analyzed to determine the independent factors of 6MWT. An equation to predict 6MWT were generated by forward stepwise multiple linear regression analysis.


      The data of 275 patients (mean age: 62.20±14.57 years, 64.7% male) were analyzed. The mean 6MWT was 179.14±92.18 m at discharge, and increased to 335.20±115.51 m at the 4–6-week follow-up. The 6MWT at the 4–6-week follow-up was independently correlated with 6MWT at discharge, regular exercise, age, gender, and preoperative New York Heart Association (NYHA) classification.


      The independent predictors: 6MWT at discharge, regular exercise, age, gender, and NYHA classification were used to generate an equation to predict 6MWT at 4–6 weeks after hospital discharge.



      6MWT (six-minute walk test), CABG (coronary artery bypass graft), NYHA (New York Heart Association), BMI (body mass index), DM (diabetes mellitus), HT (hypertension), DLP (dyslipidemia), CKD (chronic kidney disease), AF (atrial fibrillation), EF (ejection fraction), LOS (length of hospital stay)
      To read this article in full you will need to make a payment

      Purchase one-time access:

      Academic & Personal: 24 hour online accessCorporate R&D Professionals: 24 hour online access
      One-time access price info
      • For academic or personal research use, select 'Academic and Personal'
      • For corporate R&D use, select 'Corporate R&D Professionals'


      Subscribe to Heart & Lung: The Journal of Cardiopulmonary and Acute Care
      Already a print subscriber? Claim online access
      Already an online subscriber? Sign in
      Institutional Access: Sign in to ScienceDirect


        • Ghashghaei F.
        • Sadeghi M.
        • Marandi S.
        • Ghashghaei S.
        Exercise-based cardiac rehabilitation improves hemodynamic responses after coronary artery bypass graft surgery.
        ARYA Atheroscler. 2012; 7: 151-156
        • Prabhu N.
        • Maiya A.
        • Prabhu N.
        Impact of cardiac rehabilitation on functional capacity and physical activity after coronary revascularization: a scientific review.
        Cardiol Res and Pract. 2020; : 1-9
        • Shirani T.
        • Haybar H.
        • Pakseresht S.
        Evaluation of cardiac rehabilitation on functional capacity in depressed and nondepressed patients after angioplasty.
        J Family Med Prim Care. 2018; 7: 1304-1308
        • Chen Y.-.C.
        • Chen K.-.C.
        • Lu L-H
        • Wu Y.-.L.
        • Lai T.-.J.
        • Wang C.-.H.
        Validating the 6-minute walk test as an indicator of recovery in patients undergoing cardiac surgery.
        Medicine (Baltimore). 2018; 97: e12925
        • Oliveira G.
        • Carvalho V.
        • de Assis Cacau L.
        • de Araújo Filho A.
        • de Cerqueira Neto M.
        • da Silva W.
        • et al.
        Determinants of distance walked during the six-minute walk test in patients undergoing cardiac surgery at hospital discharge.
        J Cardiothorac Surg. 2014; 9
        • Fiorina C.
        • Vizzardi E.
        • Lorusso R.
        • Maggio M.
        • De Cicco G.
        • Nodari S.
        • et al.
        The 6-min walking test early after cardiac surgery. Reference values and the effects of rehabilitation programme.
        Eur J Cardiothorac Surg. 2007; 32: 724-729
        • Zielinska D.
        • Bellwon J.
        • Rynkiewicz A.
        • Elkady M.
        Prognostic Value of the Six-Minute Walk Test in Heart Failure Patients Undergoing Cardiac Surgery: a Literature Review.
        Rehabil Res Pract. 2013; : 1-5
        • Ferreira J.
        • Metra M.
        • Anker S.
        • Dickstein K.
        • Lang C.
        • Ng L.
        • et al.
        Clinical correlates and outcome associated with changes in 6-minute walking distance in patients with heart failure: findings from the BIOSTAT-CHF study.
        Eur J Heart Fail. 2019; 21: 218-226
        • Omar H.
        • Guglin M.
        Determinants of improvement in six-minute walk distance from admission to discharge in acute systolic heart failure: analysis from the ESCAPE trial.
        Cardiol J. 2017; 24: 227-230
        • Joobeur S.
        • Rouatbi S.
        • Latiri I.
        • Sfaxi R.
        • Ben Saad H
        Influencing factors of the 6-minute-walk distance in adult Arab populations: a literature review.
        Tunis Med. 2016; 94: 339-348
        • Radi B.
        • Ambari A.M.
        • Dwiputra B.
        • Intan R.E.
        • Triangto K.
        • Santoso A.
        • et al.
        Determinants and prediction equations of six-minute walk test distance immediately after cardiac surgery.
        Front Cardiovasc Med. 2021; : 1-8
        • Faggiano P.
        • D'Aloia A.
        • Gualeni A.
        • Brentana L.
        • Cas L
        The 6 min-walking test in chronic heart failure: indications, interpretation and limitations from a review of the literature.
        European J Heart Fail. 2004; 6: 687-691
        • Woo M.
        • Moser D.
        • Stevenson L.
        • Stevenson W.
        Six-minute walk test and heart rate variability: lack of association in advanced stages of heart failure.
        Am J Crit Care. 1997; 6: 348-354
        • La Rovere M.
        • Pinna G.
        • Maestri R.
        • Olmetti F.
        • Paganini V.
        • Riccardi G.
        • et al.
        The 6-minute walking test and all-cause mortality in patients undergoing a post-cardiac surgery rehabilitation program.
        Eur J Prev Cardiol. 2013; 22: 20-26
        • De Feo S.
        • Tramarin R.
        • Faggiano P.
        • Ambrosetti M.
        • Riccio C.
        • Diaco T.
        • et al.
        The inability to perform a 6 min-walking test after cardio-thoracic surgery is a marker of clinical severity and poor outcome. Data from the ISYDE-2008 Italian survey.
        Int J Cardiol. 2011; 151: 115-116
        • Yasud M.
        • Songsaengrit B.
        • Kittipanya-ngam P.
        Factors affecting distance of 6-minute walk test in post cardiovascular surgery patients after discharge at Queen Sirikit Heart Center of the Northeast.
        Srinagarind Med J. 2020; 35: 687-693
      1. ATS statement: guidelines for the six-minute walk test.
        Am J Respir Crit Care Med. 2002; 166: 111-117
        • Cohen J.
        Statistical Power Analysis For the Behavioral Sciences.
        2nd ed. Academic Press, New York1988
        • Ben Saad H.
        • Prefaut C.
        • Tabka Z.
        • Hadj Mtir A.
        • Chemit M.
        • Hassaoune R.
        • et al.
        6-minute walk distance in healthy North Africans older than 40 years: influence of Parity.
        Respir Med. 2009; 103: 74-84