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Updated: Mar 25, 2026
A Novel Digital Platform for a Monitored Home-based Cardiac Rehabilitation Program
Published on: April 19, 2019
Relationship Between Exercise Workload During Cardiac Rehabilitation and Outcomes in Patients With Coronary Heart
Clinton A Brawner1, Khaled Abdul-Nour1, Barry Lewis1
1Division of Cardiovascular Medicine, Henry Ford Hospital, Detroit, Michigan.
Insights
Exercise workload, measured in metabolic equivalents of task (METs), during cardiac rehabilitation (CR) is a key predictor of prognosis for coronary heart disease patients. Higher METs achieved indicate better outcomes and lower risk of adverse events.
Area of Science:
- Cardiology
- Exercise Physiology
- Public Health
Background:
- Coronary heart disease (CHD) necessitates comprehensive management, including cardiac rehabilitation (CR).
- Assessing exercise capacity is crucial for risk stratification in CHD patients undergoing CR.
Purpose of the Study:
- To investigate the association between exercise workload, quantified as metabolic equivalents of task (METs), and clinical outcomes in patients with CHD undergoing CR.
- To determine if METs achieved during CR can predict prognosis and identify high-risk individuals.
Main Methods:
- Retrospective observational study of 1,726 CHD patients in CR from 1998-2007.
- METs calculated from treadmill workload; Cox regression analysis used for prognosis prediction.
- Composite outcome included all-cause mortality, nonfatal myocardial infarction, or heart failure hospitalization.
Main Results:
- Higher METs at both the start and end of CR were independently associated with a reduced risk of adverse events (composite outcome).
- Patients achieving less than 3.5 METs upon CR exit were identified as a high-risk group with significantly elevated event rates.
- Hazard ratios indicated a protective effect of increased exercise capacity during CR.
Conclusions:
- METs achieved during CR serve as a valuable, cost-effective prognostic marker for CHD patients.
- Identifying patients with low exercise capacity (e.g., <3.5 METs) can guide interventions such as closer monitoring or extended CR programs.
- Optimizing exercise capacity in CR is vital for secondary prevention and improving long-term outcomes in CHD survivors.
Abstract:
The purpose of this retrospective, observational study was to describe the relation between exercise workload during cardiac rehabilitation (CR), expressed as metabolic equivalents of task (METs), and prognosis among patients with coronary heart disease. We included patients with coronary heart disease who participated in CR between January 1998 and June 2007. METs were calculated from treadmill workload. Cox regression analysis was used to describe the relationship between METs and time to a composite outcome of all-cause mortality, nonfatal myocardial infarction, or heart failure hospitalization. Among 1,726 patients (36% women; median age 59 years [interquartile range, 52 to 66]), there were 467 events (27%) during a median follow-up of 5.8 years (interquartile range, 2.6 to 8.7). In analyses adjusted for age, sex, Charlson co-morbidity index, hypertension, diabetes, and CR referral diagnosis, METs were independently related to the composite outcome at CR start (Wald chi-square 43, hazard ratio 0.59 [95% confidence interval 0.51 to 0.70]) and CR end (Wald chi-square 47, hazard ratio 0.68 [95% confidence interval 0.61 to 0.76]). Patients exercising below 3.5 METs on exit from CR represent a high-risk group with 1- and 3-year event rates ≥7% and ≥18%, respectively. In conclusion, METs during CR is available at no additional cost and can be used to identify patients at increased risk for an event who may benefit from closer follow-up, extended length of stay in CR, and/or participation in other strategies aimed at maximizing adherence to secondary preventive behaviors and improving exercise capacity.
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