Hospital-to-Home Transitional Cardiac Rehabilitation After Cardiac Surgery

Design and setting. Single-blind, parallel-group randomised controlled trial conducted at the Heart Center, Cheng Hsin General Hospital, Taipei, Taiwan. Allocation used a random number table with permuted blocks of four; outcome assessors were not involved in allocation or in delivering training.

Exercise prescription. In both groups aerobic exercise was prescribed from the baseline cardiopulmonary exercise test, targeting 60-80% of heart rate reserve and a rating of perceived exertion of 11-13, with 5-10 minutes of warm-up, 20-30 minutes of conditioning and 5-10 minutes of cool-down. Resistance training used elastic bands (four exercises, ten repetitions, increasing to eight exercises and fifteen repetitions from week three) twice weekly in the hybrid group, and a weekly 50-minute group class in the control group.

Protocol-specified outcomes not collected. Four secondary outcomes listed in the approved protocol were not collected: patient satisfaction with the rehabilitation model; patient-reported time and monetary cost of participation; home physical activity volume, frequency, duration and intensity; and home blood pressure records. These are reported as missing outcomes rather than as null findings.

Post-hoc exploratory analysis. After the trial had begun, healthcare utilisation data for the six months following enrolment (outpatient visits, cardiology outpatient visits, emergency department visits, inpatient days and the corresponding billed amounts) were additionally extracted from hospital records. These were not pre-specified and are reported as post-hoc exploratory analyses only; they are not listed among the outcome measures of this registration and are not used for confirmatory inference. Rehabilitation programme fees for control participants were advanced by the research grant; although recorded under the self-pay category in the hospital billing system, these amounts were not paid by participants and do not represent patient out-of-pocket expenditure.

Analysis. The approved protocol specified two-way analysis of variance. Analysis of covariance adjusted for the baseline value was used instead, on methodological grounds; the protocol-specified two-way analysis of variance was also performed as a sensitivity analysis and gave the same conclusions. Missing data in the intention-to-treat analysis were handled by multiple imputation using predictive mean matching. These changes are documented in protocol version 9.

Registration. This trial was registered retrospectively. Registration was planned for March 2023 but was not completed at that time; no participant data were altered and the analysis plan is documented in the approved protocol and its version 9 amendment.

Inclusion criteria

• Aged 20 to 75 years.
• Admitted to the department of cardiovascular surgery and undergoing cardiac surgery during the index admission.
• Meeting the indications for cardiac rehabilitation.
• Classified as low risk (Class B) for exercise training according to the 2013 American Heart Association exercise standards, that is, clinically stable coronary artery disease, valvular heart disease, congenital heart disease, cardiomyopathy, or an abnormal exercise test not reaching high-risk criteria.
• Able to self-monitor exercise intensity. Exclusion Criteria
• An irreversible condition causing exercise intolerance or limiting exercise capacity.
• Persistent atrial fibrillation or non-sustained ventricular tachycardia within the preceding six months, an implanted defibrillator, or any other rhythm that could compromise the reliability of home heart-rate recording.
• Hypertrophic cardiomyopathy or recent myocarditis.
• New York Heart Association class III or IV; angina or ischaemic electrocardiographic change during moderate-intensity exercise; a fall in systolic blood pressure during exercise; non-sustained ventricular tachycardia; previous cardiac arrest; or any condition judged by the physician to be potentially life-threatening.
• During the study, reported adverse symptoms or escalation of exercise-training risk to Class C or D, including suspected angina, abnormal dyspnoea, vomiting or syncope, or an emergency department visit or readmission.
• Unable to operate the communication and exercise applications independently.
• Declined to take part in testing.