NCT07428122

Brief Summary

The My Heart Counts Cardiovascular Health Study will utilize mobile health capabilities of smartphones to assess daily activity measures and compare these to measures of cardiovascular health risk factors and fitness. The study aims to collect cardiovascular health data on a diverse population by making the application available on both iOS and Android platforms. Using smartphone sensors and connected devices, the study will collect physical activity metrics, heart rate data, and responses to health questionnaires. The study includes a randomized crossover trial component examining the effectiveness of personalized activity coaching prompts generated by a language model compared to generic prompts.

Trial Health

65
Monitor

Trial Health Score

Automated assessment based on enrollment pace, timeline, and geographic reach

Enrollment
15,000

participants targeted

Target at P75+ for not_applicable

Timeline
117mo left

Started Apr 2026

Longer than P75 for not_applicable

Status
not yet recruiting

Health score is calculated from publicly available data and should be used for screening purposes only.

Trial Relationships

Click on a node to explore related trials.

Study Timeline

Key milestones and dates

Study Progress1%
Apr 2026Dec 2035

First Submitted

Initial submission to the registry

June 13, 2025

Completed
9 months until next milestone

First Posted

Study publicly available on registry

February 23, 2026

Completed
2 months until next milestone

Study Start

First participant enrolled

April 30, 2026

Completed
9.7 years until next milestone

Primary Completion

Last participant's last visit for primary outcome

December 31, 2035

Expected
Same day until next milestone

Study Completion

Last participant's last visit for all outcomes

December 31, 2035

Last Updated

February 23, 2026

Status Verified

February 1, 2026

Enrollment Period

9.7 years

First QC Date

June 13, 2025

Last Update Submit

February 19, 2026

Conditions

Keywords

physical activityfitnessheart healthmobile healthdigital healthcardiovascular riskbehavioral interventions

Outcome Measures

Primary Outcomes (1)

  • Change in Physical Activity levels

    Change in daily physical activity levels as measured by step count smartphone sensors and connected health devices.

    Time Frame: 14 days (7 days in each intervention period)

Study Arms (2)

Personalized LLM Coaching

ACTIVE COMPARATOR
Behavioral: Personalized LLM Coaching

Generic Activity Prompts

PLACEBO COMPARATOR
Behavioral: Generic Activity Prompts

Interventions

Participants receive daily text messages containing exercise coaching prompts generated by a large language model (LLM) that are personalized to the user's demographic information for a period of 7 days.

Personalized LLM Coaching

Participants receive generic daily activity prompts for a period of 7 days (e.g., "Push yourself! Reach 10,000 steps today.")

Generic Activity Prompts

Eligibility Criteria

Age18 Years+
Sexall
Healthy VolunteersYes
Age GroupsAdult (18-64), Older Adult (65+)

You may qualify if:

  • years of age or older
  • Resident of the United States
  • Able to read, understand and consent to study

You may not qualify if:

  • Not owning a compatible iOS or Android smartphone

Contact the study team to confirm eligibility.

Sponsors & Collaborators

MeSH Terms

Conditions

Motor Activity

Condition Hierarchy (Ancestors)

Behavior

Central Study Contacts

Anders Johnson

CONTACT

Daniel Seung Kim,, MD, PhD, MPH

CONTACT

Study Design

Study Type
interventional
Phase
not applicable
Allocation
RANDOMIZED
Masking
NONE
Purpose
PREVENTION
Intervention Model
CROSSOVER
Sponsor Type
OTHER
Responsible Party
PRINCIPAL INVESTIGATOR
PI Title
Chair, Department of Medicine

Study Record Dates

First Submitted

June 13, 2025

First Posted

February 23, 2026

Study Start

April 30, 2026

Primary Completion (Estimated)

December 31, 2035

Study Completion (Estimated)

December 31, 2035

Last Updated

February 23, 2026

Record last verified: 2026-02

Data Sharing

IPD Sharing
Will not share