Rationale and Design of the mTECH‐Rehab Randomized Controlled Trial: Impact of a Mobile Technology Enabled Corrie Cardiac Rehabilitation Program on Functional Status and Cardiovascular Health

Abstract

Background

Cardiac rehabilitation (CR) is an evidence‐based, guideline‐recommended intervention for patients recovering from a cardiac event, surgery or procedure that improves morbidity, mortality, and functional status. CR is traditionally provided in‐center, which limits access and engagement, most notably among underrepresented racial and ethnic groups due to barriers including cost, scheduling, and transportation access. This study is designed to evaluate the Corrie Hybrid CR, a technology‐based, multicomponent health equity‐focused intervention as an alternative to traditional in‐center CR among patients recovering from a cardiac event, surgery, or procedure compared with usual care alone.

Methods

The mTECH‐Rehab (Impact of a Mobile Technology Enabled Corrie CR Program) trial will randomize 200 patients who either have a diagnosis of type 1 myocardial infarction or who undergo coronary artery bypass grafting surgery, percutaneous coronary intervention, heart valve repair, or replacement presenting to 4 hospitals in a large academic health system in Maryland, United States, to the Corrie Hybrid CR program combined with usual care CR (intervention group) or usual care CR alone (control group) in a parallel arm, randomized controlled trial. The Corrie Hybrid CR program leverages 5 components: (1) a patient‐facing mobile application that encourages behavior change, patient empowerment, and engagement with guideline‐directed therapy; (2) Food and Drug Administration‐approved smart devices that collect health metrics; (3) 2 upfront in‐center CR sessions to facilitate personalization, self‐efficacy, and evaluation for the safety of home exercise, followed by a combination of in‐center and home‐based sessions per participant preference; (4) a clinician dashboard to track health data; and (5) weekly virtual coaching sessions delivered over 12 weeks for education, encouragement, and risk factor modification. The primary outcome is the mean difference between the intervention versus control groups in distance walked on the 6‐minute walk test (ie, functional capacity) at 12 weeks post randomization. Key secondary and exploratory outcomes include improvement in a composite cardiovascular health metric, CR engagement, quality of life, health factors (including low‐density lipoprotein‐cholesterol, hemoglobin A1c, weight, diet, smoking cessation, blood pressure), and psychosocial factors. Approval for the study was granted by the local institutional review board. Results of the trial will be published once data collection and analysis have been completed.

Conclusions

The Corrie Hybrid CR program has the potential to improve functional status, cardiovascular health, and CR engagement and advance equity in access to cardiac rehabilitation.

Registration

URL: https://www.clinicaltrials.gov; Unique identifier: NCT05238103.

Nonstandard Abbreviations and Acronyms

AACVPR

American Association of Cardiovascular and Pulmonary Rehabilitation

Corrie HCR

Corrie Hybrid Cardiac Rehabilitation

CR

cardiac rehabilitation

BACKGROUND AND RATIONALE

Cardiac rehabilitation (CR) is a multicomponent intervention with the core elements of supervised and monitored exercise: nutrition, and tobacco cessation counseling; lipid, weight, blood pressure (BP), and diabetes management; and promotion of psychological health when indicated, as outlined in the scientific statement by the American Heart Association and American Association of Cardiovascular and Pulmonary Rehabilitation (AACVPR). ¹ Overwhelming evidence, including data from randomized controlled trials, support the benefit of CR in improving cardiovascular morbidity and mortality among patients with cardiovascular disease (CVD) with cardiac events or who undergo cardiac interventions. ² , ³ , ⁴ Furthermore, high‐quality evidence supports prompt initiation of secondary prevention measures for individuals with CVD, soon after the event. ⁵

Despite the well‐established benefits of CR, participation in CR programs is alarmingly low with only 1 in 5 eligible patients attending in‐center CR. ⁶ , ⁷ , ⁸ Individuals from underrepresented racial and ethnic groups are less likely than White individuals to participate in CR. Asian, Black, and Hispanic individuals are 20%, 30%, and 37% less likely to participate, respectively. ⁷ Multiple factors contribute to low CR participation including patient‐oriented, medical, and health care system factors. ⁹ , ¹⁰ Examples of patient‐oriented factors include older age, limited social support, low socioeconomic status, and low health literacy, among others. Medical factors include multiple comorbidities. Health care system factors include lack of clinician referral, limited facilitation of enrollment after referral, and lack of outpatient CR program availability, among others. ⁹ The COVID‐19 pandemic exacerbated CR access as 143 CR facilities closed between 2019 and 2021 and CR participation declined overall. ¹¹

The rapid increase in smartphone ownership in the US and global population may allow CR programs to reach patients who were previously unable to participate in CR. ¹² , ¹³ Early evidence suggests that virtual and hybrid home‐based CR delivery could be noninferior to center‐based CR for functional status improvement ¹⁰ and can better promote health equity by eliminating logistical and geographical barriers (eg, access to transportation, parking, and limited operating hours of CR centers). However, virtual CR also presents additional challenges including access to the internet and varying levels of technology literacy. ⁷

Corrie is an equity‐first, evidence‐based, mobile health technology‐enabled digital health intervention that was designed by a multidisciplinary team of patients, health partners, clinicians, designers, and engineers at Johns Hopkins University in collaboration with Apple to support engagement with guideline‐directed therapy among patients recovering from a cardiac event. ¹⁴ The Corrie intervention was first evaluated in the MiCORE (Myocardial Infarction [MI], Combined‐Device, Recovery Enhancement) study ¹⁵ as a patient‐facing self‐management tool following acute MI. In the MiCORE study, the Corrie intervention consisted of a smartphone application and Bluetooth‐connected devices to support medication adherence, education, vitals and activity tracking, and coordination of post acute care. Among 1064 patients recovering from acute MI, those discharged with the Corrie intervention had a 52% lower risk for unplanned, all‐cause, 30‐day readmissions. There was no difference in digital health intervention use across different age, sex, or racial and ethnic groups. ¹⁵ , ¹⁶

In response to professional society calls to extend CR services to the home, and in response to the COVID‐19 pandemic, ¹⁷ we expanded the Corrie intervention into the multicomponent Corrie Hybrid Cardiac Rehab (Corrie HCR) program described here. With the mTECH‐Rehab trial, we aim to evaluate the efficacy and safety of the Corrie HCR program among diverse patients with an indication for CR, such as those recovering from acute MI, coronary artery bypass grafting surgery, percutaneous coronary intervention, valvular heart surgery, or transcatheter aortic valve replacement.

METHODS

The data that will support the findings of this study will be available from the corresponding author upon reasonable request, following completion of the study. This study protocol has been approved by the institutional review board (IRB00308410).

Trial Objectives

The primary objective of the study is to assess the efficacy of Corrie HCR in improving functional capacity among study participants. We will evaluate the distance participants walk using the 6‐minute walk test (6MWT) at 12 weeks post‐randomization. ¹⁸ , ¹⁹ Secondary objectives include assessment of the change in the composite score of secondary CVD prevention metrics (Table 1), ²⁰ the difference in CR engagement (whether 12 or more sessions were attended within 90 days of a CVD event – Healthcare Effectiveness Data and Information Set measure for patient engagement in CR), ²¹ and change in the quality of life at 12 weeks post‐randomization. ²² We will also evaluate exploratory outcomes and other measures that might contribute to the heterogeneity of treatment effects, including clinical characteristics, psychosocial factors, and safety outcomes (Table 2). In the intervention arm, we will evaluate user engagement and satisfaction.

Table 1.

Cardiovascular Secondary Prevention Metric Components

Diabetes	Ideal	Diagnosis of diabetes: HbA1c <7% No diagnosis of diabetes: HbA1c <5.7%
	Intermediate	Diagnosis of diabetes: HbA1c 7%–7.9% No diagnosis of diabetes: HbA1c 5.7%–6.4%
	Poor	Diagnosis of diabetes: HbA1c ≥8% No diagnosis of diabetes: HbA1c ≥6.5%
Blood pressure	Ideal	SBP <130 mm Hg and DBP <80 mm Hg
	Intermediate	SBP 130–139 mm Hg or DBP 80–89 mm Hg
	Poor	SBP ≥140 or DBP ≥90 mm Hg
Cholesterol	Ideal	LDL‐C <70 mg/dL
	Intermediate	LDL‐C 70–99 mg/dL
	Poor	LDL‐C ≥100 mg/dL
Weight	Ideal	BMI <25 kg/m2
	Intermediate	BMI 25–29 kg/m2
	Poor	BMI ≥30 kg/m2
Physical activity	Ideal	≥150 min/wk moderate physical activity, ≥75 min/wk vigorous physical activity, or ≥150 min/wk moderate and vigorous physical activity
	Intermediate	1–149 min/wk moderate physical activity, 1–74 min/wk vigorous physical activity, or 1–149 min/wk moderate and vigorous physical activity
	Poor	None
Smoking	Ideal	Never smoker (<100 cigarettes in lifetime)
	Intermediate	Former smoker
	Poor	Current smoker
Diet	Ideal	Rate Your Plate 64–81
	Intermediate	Rate Your Plate 46–63
	Poor	Rate Your Plate 27–45
	For each component ideal profile is consistent with a score of 2, intermediate profile is consistent with a score of 1, and poor profile with a score of 0. Subsequently a total score ranging from 0 (worst cardiovascular health) to 14 points (best cardiovascular health) is calculated.

BMI indicates body mass index; DBP, diastolic blood pressure; HbA1c, glycosylated hemoglobin; LDL‐C, low‐density lipoprotein cholesterol; and SBP, systolic blood pressure.

Table 2.

Baseline and Outcome Measures

Outcome	Assessment of measure	Enrollment (week 0)	Closeout (week 12)
Primary outcome
Functional capacity	6‐min walk test		x
Secondary outcomes
Cardiovascular secondary prevention metric	See detailed measures in Table 1	x	x
Cardiac rehabilitation engagement	Number of cardiac rehabilitation sessions attended within 90 d of a cardiovascular event	x	x
Quality of life	Patient‐Reported Outcome Measurement Information System Global Health Scale survey 22 delivered via REDCap	x	x
Blood pressure	Systolic and diastolic blood pressure averaged over 2 measurements per time point 54	x	x
Body mass index	Derived from height and weight from electronic health record (enrollment); measured at final study visit (closeout)	x	x
Glycosylated hemoglobin	Obtained from electronic health record (enrollment); measured at final study visit (closeout)	x	x
Tobacco use status and quitting attempts	Study team developed survey administered via REDCap	x	x
Diet	Rate Your Plate 35 , 36 survey administered via REDCap	x	x
Physical activity	Rapid Assessment of Physical Activity survey 37 administered via REDCap	x	x
Lipid panel (including low‐density lipoprotein cholesterol)	Obtained from electronic health record (enrollment); measured at final study visit (closeout)	x	x
Exploratory outcomes
Depressive symptoms	Patient Health Questionnaire 8 survey 39 administered via REDCap	x	x
Anxiety	Generalized Anxiety Disorder 7 survey 40 administered via REDCap	x	x
Stress level	Perceived Stress Score 10 survey 41 administered via REDCap	x	x
Digital literacy	eHealth Literacy Scale survey 31 , 38 administered via REDCap	x	x
Patient activation	Patient Activation Measure survey 32 administered via REDCap	x	x
Safety outcomes: fall, hospitalization, emergency room visit, myocardial infarction, stroke, or death	Self‐report and team adjudication		x
Cost of care: hospital costs (in US dollars) for emergency room visits and hospital readmissions	To be assessed via the Markov model of cost‐effectiveness 43		x
User engagement (for the Intervention group only)	Smartphone app number of interactions and time spent per user, collected via Corrie Health platform user analytics		x
User satisfaction (for the Intervention group only)	System Usability Scale survey 44 adopted for the Corrie intervention		x

REDcap indicates Research Electronic Data Capture.

Trial Design

In this multisite, parallel‐arm, noninferiority randomized controlled trial (Figure 1), we will evaluate the efficacy of the multicomponent Corrie HCR program plus usual care CR (intervention group) compared with usual care CR alone (control group). We aim to enroll 200 patients who are admitted to participating hospitals and who will be randomized in a 1:1 allocation ratio to control and intervention groups. The trial design was investigator‐initiated with periodic reporting to the study sponsor (American Heart Association).

Figure 1. mTECH‐Rehab study flow diagram.

ASCVD indicates atherosclerotic cardiovascular disease; BP, blood pressure; CABG, coronary artery bypass graft surgery; CR, cardiac rehabilitation; LDL‐C, low density lipoprotein cholesterol; NSTEMI, non–ST‐segment–elevation myocardial infarction; PCI, percutaneous coronary intervention; and STEMI, ST‐segment–elevation myocardial infarction

Study Setting, Recruitment, and Participant Timeline

We aim to recruit adults who present to 4 hospitals within the Johns Hopkins Health System (Johns Hopkins Hospital, Johns Hopkins Bayview Medical Center, Howard County General Hospital, and Suburban Hospital), with the following primary diagnosis or interventions: MI (ST‐segment–elevation MI and/or type 1 non–ST‐segment–elevation MI), coronary artery bypass grafting surgery, percutaneous coronary intervention, valvular heart surgery, or transcatheter aortic valve replacement. We aim to recruit 50% female, 14% Black, 18.9% Hispanic, and 6.1% Asian participants to reflect the current US population. We review enrollment rates based on sex, race and ethnicity during weekly trial meetings. The study team will identify barriers to enrolling patients from underrepresented racial and ethnic groups and women and will consider making modifications to the enrollment process if needed to meet the recruitment goals.

Eligible patients will be identified by a combination of an electronic health record screening tool and a study team review of inpatient documentation to confirm qualifying diagnoses. After consideration of exclusion criteria, eligible patients will be approached for consent at the hospital or remotely via telephone (using Docusign for consent). A study team member will obtain baseline study measurements (Table 2) from patients who consent to participate. For all patients enrolled in the study (intervention and control), a study team member will place a referral for cardiac rehabilitation in the electronic health record, if not already placed by the primary clinical team. Following hospital discharge, there will be a 14‐day run‐in period to ensure continued participant interest, appropriate follow‐up, and verification of insurance approval for CR. Patients who meet continuation criteria will then undergo randomization. Those who are randomized to the intervention group will have the digital technology mailed to their home, undergo a remote technology onboarding session, and receive virtual coaching over 12 weeks, to match the most common duration of traditional CR programs. Final study follow‐up will occur at 12 weeks post randomization.

Randomization

Following the run‐in period, eligible patients will be randomized in a 1:1 ratio to receive the Corrie HCR program plus usual care CR or usual care CR alone. Minimization, which is a dynamic randomization technique, will be used when accounting for patients' age, sex, and treatment modality during the index hospitalization. We will use a custom‐programmed randomization module in the Research Electronic Data Capture web‐based data collection app, which has been developed and implemented by Andre Hackman at Johns Hopkins Bloomberg School of Public Health. This system applies Pocock–Simon minimization methods for trials using only categorical prognostic factors in covariate‐adaptive randomization. ²³ , ²⁴ , ²⁵ Using 80% as the probability of assignment to minimize the between‐arm difference on prognostic factors, patients will be randomized to the optimal group 80% of the time. The study team will not be involved in generating any random numbers needed in the minimization routine, which are generated by the computer.

Eligibility Criteria

Patients 18 years and older with one of the diagnoses or interventions outlined previously will be screened for exclusion criteria. We will exclude patients who (1) are at high risk for adverse events as defined by AACVPR ²⁶ at the time of enrollment; (2) have motor, cognitive, auditory, or visual impairment limiting technology use; (3) do not speak English or Spanish; or (4) are considered high‐risk for falls based on the Johns Hopkins fall risk assessment tool. ²⁷

Usual Care

Usual care is defined as medical care that is provided by the patient's clinician team, regardless of study participation status. At our enrolling hospitals, a typical clinical course is as follows: (1) hospital encounter for index cardiac event/surgery/procedure; (2) CR referral order is placed as part of standardized discharge order set; (3) CR center processes referral order, verifies insurance status, and schedules intake session (typical timeline of 2–4 weeks); and (4) CR program is initiated and continued as 30‐minute to 1‐hour exercise sessions guided by an exercise physiologist at a frequency of 2 to 3 sessions per week for up to 36 sessions, until exercise targets are met (typical timeline of 12–14 weeks to complete center‐based CR program). Aside from this typical clinical course, patients randomized to the usual care group will not be referred by the study team to any other specific programs or receive other interventions during their study participation.

Intervention: Corrie HCR Program

We engaged a diverse group of patients with CVD, their health partners (close friends or family), and clinicians (including experts in CR), to tailor the Corrie HCR program to meet end‐user needs. We leveraged human‐centered design principles to guide the process. ²⁸ The Corrie HCR program was subsequently deployed to patients as part of a quality improvement project that provided in‐depth feedback to further inform the final version of the program (Figure 2). ²⁸

Figure 2. Components of the Corrie Hybrid Cardiac Rehabilitation Program.

Corrie Hybrid Cardiac Rehabilitation Program components include (1) a patient‐facing smartphone app, (2) Food and Drug Administration‐approved smart devices (blood pressure machine, smartwatch), (3) weekly coaching calls, (4) a clinician dashboard, and (5) at least 2 in‐person cardiac rehabilitation sessions (not pictured). UX indicates user experience.

The Corrie HCR program components focus on improving physical activity levels, management of BP, weight, diet, smoking cessation, cholesterol, and blood sugar. The intervention consists of:

1. A patient‐facing smartphone app (Figure 3) that empowers patients in behavior change and engagement with guideline‐directed therapy. The app enables patients to track medications, vitals, mood, and physical activity/exercise; provides engaging evidence‐based, peer‐reviewed education at an appropriate literacy level; assists them in appointment scheduling and tracking; and offers a summary report of their progress to help develop self‐efficacy. App components are based on well‐established behavior change theories including the Health Belief Model and Social Cognitive Theory, ¹⁴ , ²⁹ refined through feedback from patients, health partners, and clinicians. ²⁸

2. Food and Drug Administration‐approved smart devices, which are integrated with the participant app, including an Omron BP monitor, Apple Watch, and Fitbit Versa collecting BP, heart rate, and step count.

3. Two upfront in‐center CR sessions to facilitate personalization, self‐efficacy, and safety, followed by a mix of in‐center/home‐based sessions per participant preference. As soon as possible after enrollment, intervention group participants will be scheduled for 2 mandatory in‐center CR sessions that will serve as a basis for personalization of the home exercise plan, improving self‐efficacy and confidence for home exercise, and assessment of safety for home exercise. To overcome financial barriers to access, we will cover transportation and parking fees using research funds for all participants randomized to the intervention group to attend the 2 required in‐center CR sessions. Regarding safety, some of the components of AACVPR criteria require patient assessment during exercise. Data obtained from in‐center exercise sessions at an AACVPR certified CR center will be evaluated against AACVPR criteria by the study team physician for clearance to participate in exercise sessions away from the CR center. We anticipate that only a small fraction of patients will have high‐risk features discovered during the initial in‐center CR sessions, as assessment for high‐risk clinical features will be performed during eligibility assessment. If a participant is newly identified to have a high‐risk feature precluding home exercise, the participant will be excluded from the study.

4. A clinician dashboard that allows for intuitive data visualization of key cardiovascular health metrics and trends including BP, weight, blood cholesterol level, heart rate, steps, medication adherence, physical activity/exercise, and education completion. The clinician can then use the data to generate actionable insights and provide tailored, comprehensive feedback to the patient.

5. Patients will receive weekly check‐in calls from a trained Corrie Health coach to guide them in individualized risk factor modification, stress reduction, and adaptation of their exercise prescription, the last of which will be performed by the exercise physiologist. If a participant reports concerning symptoms such as chest pain or shortness of breath, the health coach will follow a standard operating procedure (approved by the institutional review board) to handle the different scenarios. Additionally, the clinician dashboard will be monitored daily, and any red flag recordings will be addressed per the standardized operating procedure. Briefly, individuals who record high‐risk symptoms or vital signs will be asked to pause the exercise component of the Corrie HCR program until the safety of returning to exercise is determined by their clinician. Patients will be provided anticipatory guidance that the Corrie HCR team is not intended to replace their clinical healthcare teams or provide medical advice. Patients will be informed that when experiencing concerning symptoms, they should contact their clinicians immediately or seek emergency services by calling 911 or presenting to the emergency department. Furthermore, virtual, synchronous, audiovisual group‐based education sessions will be offered weekly by the certified exercise physiologist.

Figure 3. Corrie Hybrid Cardiac Rehabilitation smartphone application.

Shown here are various features and tabs within the Corrie smartphone application, including vitals, physical activity, medication tracking, educational materials, and clinical team contacts.

Technology Onboarding

To promote equitable engagement in the study, individuals who are randomized to the Corrie HCR program but do not own a smartphone will be provided with one. A reusable device program (iShare) was previously established and successfully implemented by our team in the MiCORE study. ¹⁵ , ³⁰ Additionally, within the intervention group, a smartwatch and Omron BP monitor will be provided to all patients who do not own them. Technology onboarding sessions will be guided by the technology startkit developed for both Apple iOS and Android platforms by our study team (see Supplemental Data S1–S2).

Participants may keep all devices after study completion to facilitate the long‐term sustainability of behavior changes associated with CR. If patients decide to stop the program during the study or within 6 months of study completion, they will be expected to return the devices to the study team. We will offer personalized onboarding and technology assistance for patients to ensure equitable technology onboarding. Digital literacy will be evaluated in 3 ways: (1) a screening questionnaire, (2) a Digital Health Care Literacy Scale, ³¹ and (3) an assessment of caregiver digital literacy and availability.

The summative assessment of digital literacy will guide the depth of the technology onboarding session. Patients will also be provided with contact information for technical questions as well as an onboarding booklet to refer to if questions arise. Finally, technology use check‐ins will be completed during weekly health coach calls.

Measures

Data on sociodemographic factors and clinical characteristics will be obtained from electronic health record review at study enrollment. Participant data on cardiovascular risk factor control (smoking, diet, physical activity), electronic health literacy (digital skills), quality of life, patient activation, and mental health factors will be obtained from surveys administered via Research Electronic Data Capture at enrollment and 12‐week post‐randomization follow up. Further information on cardiovascular risk factor control (low‐density lipoprotein cholesterol level, glycosylated hemoglobin level, systolic and diastolic BP, body mass index) will be collected at baseline using chart review and at 12 weeks post‐randomization at the Clinical Research Unit by trained nurses.

Functional status assessment via 6MWT will be performed by trained study personnel who are blinded to randomization assignment at the Clinical Research Unit using standardized protocol. Measures of participant engagement and satisfaction with technology will be collected in the intervention group only at the 12‐week post‐randomization follow‐up. Detailed descriptions of the study outcomes and measures are provided in Table 2.

Primary Outcome

• The difference in distance participants walked (ie, functional capacity) between the intervention and usual care groups, as measured by the 6MWT at 12 weeks post‐randomization. The 6MWT is a rigorously validated clinical assessment of functional performance in individuals with cardiovascular disease. ³² , ³³

Secondary Outcomes

• Difference in the composite score of a secondary cardiovascular prevention metrics (see Table 1) between the intervention and usual care groups

• Difference in CR engagement measure (the total number of CR sessions attended within 90 days of a CVD event) ²¹ between the intervention and usual care groups

• Difference in the quality of life: Patient‐Reported Outcomes Measurement Information System Global Health Scale v1.2 ²² , ³⁴ between the intervention and usual care groups

In addition to these secondary outcomes, we will measure factors that may be relevant to the heterogeneity of treatment effects and the intervention's mechanism of action, as follows:

Health Factors

• Systolic BP and diastolic BP

• Body mass index

• Glycosylated hemoglobin

• Lipid panel (including low‐density lipoprotein cholesterol)

• Tobacco use status, quitting attempts: self‐report/questionnaire

• Diet: Rate Your Plate ³⁵ , ³⁶

• Physical activity: The Rapid Assessment of Physical Activity ³⁷

Digital Skills

• eHealth literacy: eHealth Literacy Scale ³¹ , ³⁸

Psychosocial Factors

• Depressive symptoms: Patient Health Questionnaire 8 ³⁹

• Anxiety: Generalized Anxiety Disorder 7 ⁴⁰

• Perceived stress: Perceived Stress Scale ⁴¹

• Patient activation: Patient Activation Measure 10 ⁴²

Engagement in Center‐Based CR Sessions

• Number of individuals completing 2, 12, 24, and 36 in‐person CR sessions (Healthcare Effectiveness Data and Information Set measures) ²¹

• Number of CR sessions attended per individual

Safety Outcomes

• Number of falls

• Hospitalization, emergency department visits, myocardial infarction, acute coronary syndrome, transient ischemic attack, stroke, or cardiac procedures, as reported in the electronic health record or via patient/caregiver report, verified by health records

• Death, as reported in the electronic health record or via caregiver report, verified by death certificates or health records

Cost of Care

• As assessed by a Markov model of cost‐effectiveness, ⁴³ the hospital costs (in US dollars) for emergency department visits and hospital readmissions will be compared between the intervention and usual care groups

User Satisfaction and Engagement (for Intervention Arm Only)

• User engagement: total number of interactions in the smartphone app and interactions with specific features of the smartphone app per participant, collected via the Corrie Health Platform User Analytics

• User satisfaction: System Usability Scale modified for Corrie ⁴⁴

Study Design Feedback

To promote health equity and position the Corrie HCR program to improve access to CR services for individuals with diverse backgrounds, we partnered with the Johns Hopkins Center for Health Equity Community Advisory Board to obtain feedback from community stakeholders. We engaged 3 community advisory board members during 2 separate 1‐hour meetings in a 1‐week period where in‐depth discussions were held regarding the purpose of the study, trial procedures, design, outcomes, and interventions. Suggestions from the Community Advisory Board that were incorporated into the study workflow were as follows: (1) encouraging the presence of a health partner when approaching a participant for consent to increase the chance of adherence to study interventions if a participant is enrolled; (2) inquiring to understand a patient's living conditions, level of stress, and social support during enrollment to tailor follow‐up coaching calls to individual participant needs; (3) limiting the study team size to 1 to 2 people when approaching patients for consent; (4) avoiding the use of acronyms during enrollment and follow‐up calls; (5) ensuring that patients do not feel overwhelmed and are not in acute distress when approaching for consent; and (6) sharing educational videos with patients regarding the study and intervention to increase retention of new information.

Clinical trial planning was aided by the Johns Hopkins–Tufts Trial Innovation Center, ⁴⁵ a hub of the larger Trial Innovation Network. Specifically, the design and implementation of the dynamic randomization protocol using the method of minimization, including the code base and adaptation into data management software Research Electronic Data Capture, were enabled through this collaboration among study authors and consulting members, from January 2022 to April 2023. We also engaged local and national leaders in CR and patient activists to elicit feedback on our randomized controlled trial protocol. We will continue to engage patient activists and community members quarterly throughout the trial period to advise on recruitment and procedural aspects. Any amendments to the study protocol made by the core study team will be reviewed by the institutional review board, reported to the study sponsor, and updated on clinicaltrials.gov.

Sample Size and Statistical Analysis Plan

The primary outcome measure of the study is the difference in distance participants walk (ie, functional capacity) between the intervention and usual care groups, as measured by the 6MWT at 12 weeks post‐randomization. The comparison will be made in a noninferiority design. Noninferiority will be assessed on both intention‐to‐treat and per‐protocol populations at the 1‐sided 5% significance level by using the upper bound of the 2‐sided 90% CI, for the absolute difference in the mean 6MWT between the Corrie HCR and usual care CR arms. For the trial to demonstrate noninferiority with 80% power, assuming a pooled SD of 107 meters for the follow‐up 6MWT ⁴⁶ and a true 6MWT difference in favor of the Corrie HCR program of 30 m, 160 patients will be required (80 per group) to exclude a difference of >12.5 m in favor of the usual care group. The noninferiority margin of 12.5 m was chosen to represent about 40% of the minimum important difference of 30 m in 6MWT as identified in previous studies. ⁴⁷ Accounting for an attrition rate of 20% during follow‐up after randomization, a total of 200 (100 per group) participants will be recruited and randomized in a 1:1 ratio to the 2 treatment arms. We will compare the mean level of 6MWT at 12 weeks post‐randomization between the intervention and control groups using a generalized linear regression model. The sample size calculation was performed using the TWOSAMPLEMEANS statement in SAS version 9.4 procedure PROC POWER (SAS Institute Inc., Cary, NC), in which the null value option was specified to represent the noninferiority margin.

If a participant has an adverse event that results in them being discontinued from the study or does not engage with the intervention, that participant will be included in the intention‐to‐treat analysis, which is the primary form of analysis for our study. In addition to the primary intention‐to‐treat analysis, prespecified, per‐protocol analyses will be conducted (1) inclusive of intervention group participants who remain active in the study and engage with the intervention, and separately (2) among those participants (in both control and intervention arms) who have completed at least 2 in‐center CR sessions. In addition, prespecified subgroup analyses will be performed, stratified by age, sex, treatment modality (cardiac surgery, catheter‐based procedure, or medical therapy).

Blinding

Although blinding participants or study team members enrolling patients is not possible, outcome assessors will be blinded to intervention allocation. We will instruct study participants not to discuss allocation with study personnel before both the initial and follow‐up assessments.

Data Monitoring

Data management, oversight, and data analysis will be conducted by the principal investigator and other team members who are not conflicted. The principal investigator and core study team will be responsible for the decision to terminate the trial once study goals have been met or if unforeseen serious adverse events occur related to the study intervention.

Dissemination of Results

We will share study results with study participants and community advisory board members via a short video and 1‐page letter with study outcomes described at a sixth‐grade reading level. In addition, we will disseminate results at local, state, national, and international scientific organization meetings and publish findings in peer‐reviewed journals. Authorship eligibility for publications will be determined by the principal investigator and core study team. We will promote results on social media (eg, YouTube, Facebook, X) and through traditional press outlets (newspapers, radio, and TV). As outlined, we will continue our engagement with scientific organizations, insurance providers, and policymakers to ensure the dissemination of study results and their implementation. Recruitment is projected to continue for 2 years, after which study results are expected to be published.

DISCUSSION

In the mTECH‐Rehab trial, we hypothesize that participants randomized to the Corrie HCR program along with usual care CR will demonstrate improved functional status, cardiovascular health metrics, and CR engagement at 12 weeks post‐randomization that are comparable to usual care CR but achieved through an asynchronous digitally enabled home‐based approach.

Prior studies evaluating the efficacy of home‐based CR compared with in‐center CR focused on evaluating synchronous (with real‐time audiovisual communication) home CR sessions rather than asynchronous, remote exercise. ⁴⁸ , ⁴⁹ Asynchronous exercise, which has previously been proven to be feasible, ⁵⁰ is more flexible as it does not have to be conducted during work hours. This addresses a major barrier to CR engagement, which is lack of CR staff during nonbusiness hours. ⁸ In addition to promoting structured exercise, the Corrie HCR program has a strong focus on lifestyle changes and other risk factor modification with a multi‐component strategy for secondary prevention.

A Million Hearts Cardiac Rehabilitation think tank document ⁵¹ along with a CR expert document ⁵² call for the expansion of new CR delivery models that can address disparities in CR delivery and are inclusive of diverse populations. We are positioned to deliver Corrie HCR equitably as (1) we will provide the necessary technology to study participants and provide individualized technology onboarding to ensure enrollment of individuals with various levels of digital literacy, (2) we have codesigned the Corrie HCR together with diverse groups including patients, health partners, and clinicians, and (3) we will continue to consult a community advisory board to guide equitable enrollment and participation in the trial. Although access to devices or internet services can be a challenge, we are working with professional societies, policymakers, and insurance providers to find solutions. Specifically, the authors of this paper have coauthored a Scientific Advisory from the American Heart Association where equity in digital CR was emphasized. ⁵³ Trial results will help provide further evidence and strengthen the justification to expand technology and internet access for our patients.

We acknowledge several potential limitations in our study design. First, in a multi‐component intervention, it may be challenging to differentiate which component or which combination of components significantly influenced study results. Although we view each component of the intervention as being complementary to the others, future studies evaluating the role of individual components in secondary prevention could be considered. Second, the clinical characteristics of patients who experience an acute MI and undergo an urgent procedure may differ from those patients who receive treatment for stable coronary artery disease or valvular heart disease. We will analyze the data for potential interactions such as the type of cardiac event with study outcomes. Third, given the 12‐week follow‐up period, we will not be able to evaluate the long‐term effects of the intervention; however, data obtained in this study will inform the design of future long‐term studies. We note that traditional CR is a 12‐week program ³ , ⁵ and leads to reduced morbidity and mortality over long‐term follow‐up, suggesting that if we see positive effects from the Corrie HCR program, these may also translate into long‐term benefits. Lastly, despite diverse populations served at 4 different enrolling hospitals, including diversity in urban versus suburban settings, we acknowledge the lack of geographic variation in our study, where recruitment is limited to the mid‐Atlantic region in the United States.

CONCLUSIONS

The mTECH‐Rehab trial will assess whether a novel, multi‐component, and health equity‐oriented HCR (Corrie HCR) program, delivered over 12 weeks, is safe and effective in improving functional status, cardiovascular health metrics, and CR engagement among patients recovering from a cardiovascular event, procedure, or surgery.

Sources of Funding

This study is supported by an American Heart Association Health Technology and Innovation Strategically Focused Research Network Award (20SFRN35380046 and 20SFRN35490003). The Johns Hopkins University–Tufts University Trial Innovation Center is funded by the National Institutes of Health National Center for Advancing Translational Sciences (U24TR001609).

In addition to the SFRN awards above, Seth Martin, MD, MHS has received research support from American Heart Association awards #878924, #882415, #946222, the Patient‐Centered Outcomes Research Institute (ME‐2019C1‐15 328, IHS‐2021C3‐24147), the National Institutes of Health (NIH) (P01 HL108800 and R01AG071032), the David and June Trone Family Foundation, the Pollen Digital Innovation Fund, Sandra and Larry Small, Google, and Merck.

Erin Spaulding, PhD, RN has received the following financial support for the research, authorship, and publication of this paper: NIH/NHLBI T32 HL007024 Postdoctoral Fellowship in Cardiovascular Epidemiology Institutional Training.

Lena Mathews, MD, MHS was supported by the National Heart Lung Blood Institute K23HL161404 and the Johns Hopkins Clinician Scientist Award.

Disclosures

The following authors report potential conflict of interest for the submitted article:

Francoise Marvel, MD: under a license agreement between Corrie Health and the Johns Hopkins University, the university owns equity in Corrie Health. Dr Marvel is entitled to royalty distributions related to technology described in the study and discussed in this publication. Additionally, Dr Marvel is a founder of and hold equity in Corrie Health. This arrangement has been reviewed and approved by the Johns Hopkins University in accordance with its conflict of interest policies. Dr Marvel has received material support from Apple and iHealth.

Erin M. Spaulding, PhD, RN serves as a consultant to Corrie Health.

Erin D. Michos, MD, MHS has served on advisory boards for AstraZeneca, Bayer, Boehringer Ingelheim, Esperion, Novartis, Novo Nordisk, and Pfizer.

Seth Martin, MD, MHS: under a license agreement between Corrie Health and the Johns Hopkins University, the university owns equity in Corrie Health. Dr Martin is entitled to royalty distributions related to technology described in the study and discussed in this publication. Additionally, Dr Martin is a cofounder of and holds equity in Corrie Health. This arrangement has been reviewed and approved by the Johns Hopkins University in accordance with its conflict of interest policies. In addition to the research support above, Dr Martin has received material support from Apple, iHealth, and Google. Dr. Martin is on the Advisory Board for Care Access and reports personal consulting fees from Amgen, AstraZeneca, BMS, Chroma, Kaneka, NewAmsterdam, Novartis, Novo Nordisk, Premier, Sanofi, and 89bio.

Supporting information

Data S1–S2