An interventional study of Standard cardiac rehabilitation and Time-Restricted Eating in Coronary Artery Disease, sponsored by University of Toronto. Completed at 1 site in Canada. Open to participants aged 18 Years and older. Per ClinicalTrials.gov, last updated 2026-08-20.
Sponsored by University of Toronto · Not applicable, Interventional, and Treatment
This study will use a form of intermittent fasting called time-restricted eating (TRE) where individuals consume ad libitum energy intake within a set window of time, commonly 8 hours, which induces a fasting window of 16 hours per day (i.e., 16:8 TRE). TRE could be an effective addition to cardiac rehabilitation as it has demonstrated cardiovascular health benefits and potential for synergy when combined with exercise training. This study will determine if TRE is a feasible and safe nutrition intervention during cardiac rehabilitation and if TRE improves the health benefits of cardiac rehabilitation compared to cardiac rehabilitation alone.
HYPOTHESIS
JUSTIFICATION: Past animal and human clinical trials have demonstrated TRE to be beneficial in realigning circadian rhythm, improve coronary artery disease (CAD) and peripheral artery disease (PAD) through the reduction in calorie intake, and promote cell signalling and repair pathways during the fasting period. TRE has not been tested in patients with CAD or other heart diseases but has shown to improve comorbid conditions (diabetes and hypertension) and improve metabolic profiles (blood pressure, hemoglobin A1c, fasting glucose, insulin sensitivity, and lipid profiles. Additionally, TRE when combined with exercise, such as in cardiac rehabilitation programs, improves VO2 peak and reduces fat mass compared to exercise alone. The proposed study will deliver a TRE intervention in combination with the cardiac rehabilitation program and is expected to be feasible, safe, and improve outcomes of cardiac rehabilitation.
OBJECTIVES: The primary aim of this study is to evaluate the feasibility (adherence) and safety (adverse events) of TRE in combination with cardiac rehabilitation.
The secondary aim is to assess the efficacy of the intervention on:
4.Cardiac rehabilitation adherence
Exploratory aims of the study include identifying sex differences (equal recruitment of males and females) and participants' experience with TRE (including confidence in maintaining this eating pattern or modifications to increase adherence).
RESEARCH METHOD This study will be a two-site (Toronto Rehabilitation Institute and Toronto Western Hospital), 2-arm, parallel-group, randomized feasibility trial of cardiac rehabilitation alone or cardiac rehabilitation plus 16:8 TRE. Men and women who are referred through the standard clinical pathways for coronary artery disease and are willing to accept random assignment and complete the study assessments will be enrolled. Both groups will receive the standard, multi-dimensional cardiac rehabilitation program consisting of physician-directed risk factor management, an individualized exercise prescription, and virtual education. Participants randomized to the TRE group will be asked to eat only between 11 am and 7 pm for the duration of the cardiac rehabilitation program (\~16 weeks). Adherence will be collected via twice daily text messages asking participants to respond with the time they started and stopped eating. Safety will be collected by self-report and medical records. Efficacy outcomes will be assessed by cardiopulmonary exercise test, blood draw, dual x-ray absorptiometry, 3-day diet records, accelerometers, and questionnaires. Study outcomes will be measured at baseline and at the end of the cardiac rehabilitation program.
SAMPLE SIZE A priori sample size for recruitment (n=60, 30 per group, equal recruitment of sex) was not fully achieved within the study period. Over the course of two years, the study efforts successfully recruited 30 male participants within the first 12 months of recruitment. Only 15 female participants were recruited after 2 years of recruitment efforts. The lower enrollment rate of females reflects both time limitations on the recruitment window and less females attending cardiac rehabilitation within the study criteria. The study team decided to end recruitment at n=45 (30 males, 15 females) after 2 years of recruitment due to personnel limitations
STATISTICAL ANALYSIS Participant characteristics will be summarized using descriptive statistics. For adherence, both the text message response rate and adherence rate to the 16-hour daily fast will be reported. The change in caloric intake, diet quality, physical activity and efficacy outcomes will be compared between groups by analysis of covariance with baseline values as covariates. Relative risk will be used to compare the incidence of safety outcomes between groups. The primary analysis will be intention to treat and performed with both sexes combined. Secondary analyses will be performed separately in each sex.
5,598 studies on the registry are indexed under Coronary Artery Disease; 955 are open to participants now.
This study's enrollment of 45 is below the median of 123 across 3,435 interventional studies indexed under Coronary Artery Disease.
Browse Coronary Artery Disease studies →University of Toronto is the lead sponsor of 397 studies on the registry; 59 are open to participants now.
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Exclusion Criteria:
The 16-week program consists of physician-directed risk factor management, an individualized aerobic and resistance exercise prescription, and virtual education on disease management and lifestyle behaviors (including exercise safety, stress management, and heart-healthy nutrition), and an assessment with a registered dietitian and individualized recommendations for a heart-healthy diet. Additionally, selected patients with identified issues such as depression, anxiety, trouble sleeping, anger and social and emotional issues will receive one-on-one counselling with a psychologist or social worker.
Behavioral: Standard cardiac rehabilitation
Participants in this group will receive the same standard assessment and individualized recommendations as the comparator group, but will also be counselled to restrict their eating to between 11 am and 7 pm during the program starting the evening of the consultation. They will also be advised to perform their home-based exercise sessions during the fasting period in the morning.
Behavioral: Standard cardiac rehabilitation · Behavioral: Time-Restricted Eating
Standard, multi-dimensional cardiac rehabilitation program.
Counselling to restrict their eating to between 11 am and 7 pm and to consume water-only for the remaining 16 hours per day
Adherence to the daily ≥16-hour fast for the 16-weeks of the cardiac rehabilitation program.
Assessed daily through a custom twice daily automated text message (or email) program, or written logs for those without cell phones. Adherence will be measured as a % of days with ≥16-hour fast.
Time frame: Averaged over the 16 weeks of the intervention
Cardiorespiratory fitness as measured by peak volume of oxygen consumption (VO2peak)
Assessed by an incremental, to-maximum cardiopulmonary treadmill exercise test.
Time frame: 16 weeks
Fat mass
Assessed by dual absorptiometry x-ray (DXA) scan.
Time frame: 16 weeks
Symptoms from TRE
Self-report of various nutritional impact adverse events collected at support phone calls for both groups
Time frame: 16 weeks
Seattle Angina Questionnaire score
Standard scoring of Seattle Angina Questionnaire (minimum = 0, maximum = 100, higher score means better outcome)
Time frame: 16 weeks
Adverse events
re-hospitalizations, recurrent cardiac events, death extracted from medical records
Time frame: 1-year
Fat-free mass
Assessed by dual absorptiometry x-ray (DXA) scan.
Time frame: 16 weeks
Hemoglobin A1c
Measured by blood draw
Time frame: 16 weeks
Blood pressure
Systolic and diastolic blood pressure will manually assessed as the average of the 2nd to 6th measurements
Time frame: 16 weeks
Waist circumference
Measured by an inelastic tape at the level of the top of iliac crest as the average of two measurements
Time frame: 16 weeks
Fasted blood glucose
Measured by fasted blood draw
Time frame: 16 weeks
Metabolic syndrome
As defined by the NCEP/ATP III criteria
Time frame: 16 weeks
Lipid profile
Individual measures and ratios of total cholesterol, high-density lipoprotein, low-density lipoprotein, triglycerides from fasted blood draw
Time frame: 16 weeks
Health-related quality of life measured by the RAND-36 Physical Component Summary
Physical component summary of the RAND-36 questionnaire (minimum = 0, maximum = 50, higher score is better outcome)
Time frame: 16 weeks
Macronutrient ratios
3-day food record analysed by food analysis software to estimate macronutrient intake
Time frame: 16 weeks
Caloric intake
3-day food record analysed by food analysis software to estimate intake
Time frame: 16 weeks
Cardiac rehabilitation adherence
The participant's clinical chart for the cardiac rehabilitation program will be reviewed to extract adherence data to the standard components of the program (exercise, nutrition, education, social worker)
Time frame: 16 weeks
Time-restricted eating experience
At the end of the intervention, the TRE group will complete a researcher developed questionnaire that asks questions about acceptability of TRE and confidence in continuing the intervention long-term
Time frame: 16 weeks
Mediterranean Diet Score
Standard scoring of 14-item Mediterranean Diet Score Tool (minimum = 0, maximum = 14, higher score indicates better outcome)
Time frame: 16 weeks
Physical activity and sedentary time
Participants will wear an accelerometer device for 5 days with 3 full days used for analysis
Time frame: 16 weeks
Plan to share: No
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