Six-minute walk distance after coronary artery bypass grafting compared with medical therapy in ischaemic cardiomyopathy

Stewart, R. A.H. et al. (2018) Six-minute walk distance after coronary artery bypass grafting compared with medical therapy in ischaemic cardiomyopathy. Open Heart, 5(1), e000752. (doi: 10.1136/openhrt-2017-000752) (PMID:29531766) (PMCID:PMC5845417)

Abstract

Background: In patients with ischaemic left ventricular dysfunction, coronary artery bypass surgery (CABG) may decrease mortality, but it is not known whether CABG improves functional capacity. Objective: To determine whether CABG compared with medical therapy alone (MED) increases 6 min walk distance in patients with ischaemic left ventricular dysfunction and coronary artery disease amenable to revascularisation. Methods: The Surgical Treatment in Ischemic Heart disease trial randomised 1212 patients with ischaemic left ventricular dysfunction to CABG or MED. A 6 min walk distance test was performed both at baseline and at least one follow-up assessment at 4, 12, 24 and/or 36 months in 409 patients randomised to CABG and 466 to MED. Change in 6 min walk distance between baseline and follow-up were compared by treatment allocation. Results: 6 min walk distance at baseline for CABG was mean 340±117 m and for MED 339±118 m. Change in walk distance from baseline was similar for CABG and MED groups at 4 months (mean +38 vs +28 m), 12 months (+47 vs +36 m), 24 months (+31 vs +34 m) and 36 months (−7 vs +7 m), P>0.10 for all. Change in walk distance between CABG and MED groups over all assessments was also similar after adjusting for covariates and imputation for missing values (+8 m, 95% CI −7 to 23 m, P=0.29). Results were consistent for subgroups defined by angina, New York Heart Association class ≥3, left ventricular ejection fraction, baseline walk distance and geographic region. Conclusion: In patients with ischaemic left ventricular dysfunction CABG compared with MED alone is known to reduce mortality but is unlikely to result in a clinically significant improvement in functional capacity.

• Item Type: Articles
• Additional Information: This work was supported by grants U01HL69015, U01HL59013 and R01HL105853 from the National Institutes of Health/National Heart, Lung, and Blood Institute (Clinical Trial Registration – Unique Identifier: NCT00023595).
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Petrie, Professor Mark and Cleland, Professor John
• Authors: Stewart, R. A.H., Szalewska, D., Stebbins, A., Al-Khalidi, H. R., Cleland, J. G.H., Rynkiewicz, A., Drazner, M. H., White, H. D., Mark, D. B., Roy, A., Kosevic, D., Rajda, M., Jasinski, M., Leng, C. Y., Tungsubutra, W., Desvigne-Nickens, P., Velazquez, E. J., and Petrie, M. C.
• College/School: College of Medical Veterinary and Life Sciences > School of Cardiovascular & Metabolic Health; College of Medical Veterinary and Life Sciences > School of Health & Wellbeing > Robertson Centre
• Journal Name: Open Heart
• Publisher: BMJ Publishing Group
• ISSN: 2053-3624
• Published Online: 20 February 2018
• Copyright Holders: Copyright © 2018 The Authors
• First Published: First published in Open Heart 5(1):e000752
• Publisher Policy: Reproduced under a Creative Commons License