Syed Gani Q.1,2, Kayambu G.3
1National University Hospital, National University Heart Centre, Singapore, Singapore, 2University of Chester, Department of Clinical Sciences and Nutrition, Chester, United Kingdom, 3National University Hospital, Singapore, Singapore
Background: Cardiovascular disease remains the number one cause of death in the world. Benefits of Cardiac Rehabilitation (CR) have been well researched and documented. However, the methodology for exercise prescription varies within each guideline.
Purpose: The trial assessed whether exercise prescription via Metabolic Equivalents (METs) was more effective than exercise prescription via maximum heart rate for participants undergoing CR.
Methods: Participants were enrolled from National University Heart Centre Singapore, CR Program. All participants were accepted for CR following medical or physician referral with a diagnosis following Percutaneous Coronary Intervention (PCI), Coronary Artery Bypass Graft (CABG) or valve surgery. For the physiotherapy intervention, each participant was assessed and prescribed individual aerobic exercise via METs. Participants from the control group were prescribed individual aerobic exercise via maximum heart rate. Furthermore, participants from the control group were also chosen to match the cardiac diagnosis of participants from intervention group. The primary outcome measure was the Six-Minute Walk Test (6MWT) conducted on the first and twelfth session. Secondary outcomes included physical and mental Health-Related Quality of Life (HRQoL) determined via Short Form questionnaire-36 items Version 2 (SF-36v2) for intervention group only.
Results: 19 participants were enrolled into the intervention group (mean age 57 ± 10), and control group (mean age 58 ± 10) respectively. Breakdown of participants based on diagnosis within each group included 11 PCI, seven CABG and one valve surgery. Exercise prescription via METs led to similar 6MWT distance improvements when compared with exercise prescription via maximum heart rate (p = 0.86). There was a moderate inverse correlation between initial 6MWT distance and distance improved (r = -0.62, p = 0.005). CR resulted in improvements in physical component score (p = 0.001) but not mental health score
(p = 0.32). Moreover, there was a moderate correlation between distance improved and change in physical component score (r = 0.45, p = 0.05).
Conclusion(s): Improvement in 6MWT distance was similar when exercise was prescribed via maximum heart rate or METs. Participants with lower physical function have greater improvement in the 6MWT distance as compared to participants with higher physical function. Furthermore, CR improves physical but not mental HRQoL. Improvements in physical HRQoL were significant in participants with greater improvement in the 6MWT distance.
Implications: Benefits for exercise prescription via METs was similar to exercise prescription via maximum heart rate for participants undergoing CR. In addition, CR should address psychosocial aspect and not just improve functional capacity. To date, there are no baseline SF36v2 scores for cardiovascular patients that have attended CR in Singapore. Hence, the availability of preliminary baseline SF36v2 scores would assist CR team in early identification of reduced physical or mental HRQoL. Another set of CR may be warranted for patients with physical SF36v2 scores below the baseline. Similarly, patients with mental SF36v2 scores below the baseline may require further psychosocial assistance.
Funding acknowledgements: Awarded the AMDA 2015/16 from National University Hospital to undertake MSc in Cardiovascular Health and Prevention at University of Chester.
Topic: Professional practice: other
Ethics approval: Approved by National Healthcare Group Domain Specific Review Board reference 2016/00368, Singapore.
All authors, affiliations and abstracts have been published as submitted.
