Exercise-based cardiac rehabilitation for postcoronary artery bypass grafting and its effect on hemodynamic responses and functional capacity evaluated using the Incremental Shuttle Walking Test: A retrospective pilot analysis

Background: Coronary artery bypass grafting (CABG) is a common surgical procedure for the restoration of blood flow into stenotic or blocked coronary arteries. Cardiac rehabilitation has been implemented to some extent worldwide for the management of postoperative CABG. However, studies about the effect of exercise training on hemodynamic responses of the heart using the Incremental Shuttle Walking (ISWT) test are limited in Saudi Arabia. Objectives: To investigate the effect of exercise-based cardiac rehabilitation (Phase 3, hospital-based) on some hemodynamic responses including blood pressure, heart rate (HR) and heart rate recovery (HRR), and rate pressure product (RPP) using ISWT on post-CABG patients. Methods: Fifteen CABG (51.4 +/- 6.4 years, 14 male, 1 female) patients without altering their medication were enrolled in a hospital-based cardiac rehabilitation program (Phase 3) between 2011 and 2012 for supervised individual exercise training sessions (three times per week for 8 weeks; 60-minute session at a moderate intensity). Patients performed two tests (ISWT1 and ISWT2) and one before exercise training program and one after, during which resting systolic blood pressure (SBP) and diastolic blood pressure (DBP), post-ISWT SBP and DBP, resting HR, peak HR, HRR (which was defined as the absolute change from peak HR to 1-minute post peak HR), and RPP at rest and at the end of the ISWT were measured. Exercise training sessions included both aerobic and resistance exercises, which were preceded by a cooling down period and followed by a recovery period. Results: Paired t-test showed a significant reduction in both resting SBP (p = 0.04) and DBP (p = 0.03), and a significant increase in post-ISWT2 SBP (p = 0.004), peak HR (p = 0.003), HRR (p = 0.03), and RPP at maximum (p = 0.002) after 8 weeks of supervised exercise training. In addition, there was a significant increase in the speed and distance achieved on ISWT2 (p < 0.001) after the training program. Conclusion: Supervised exercise training (cardiac rehabilitation) for 8 weeks was effective in improving hemodynamic responses and functional exercise capacity in CABG patients. Cardiac rehabilitation should be implemented more frequently and health-care providers should be aware of its importance. Further research is needed in this area to confirm these findings in the region.