The FAPO-2 study (Patient Monitoring Tool for Clinical Observation and Arrhythmia Detection) is a prospective, interventional, non-randomized study designed to evaluate the feasibility, usability, clinical effectiveness, and cost-efficiency of a wearable-enabled remote monitoring strategy in adult cardiac patients. The intervention consists of active clinical management of patients via teleconsultations, triggered by automated alerts generated through wearable data integrated into a centralized digital platform. FAPO-2 will include patients with chronic cardiovascular conditions and those undergoing recent minimally invasive interventions. The central objective is to validate a structured model for early arrhythmia detection, remote risk stratification, and timely clinical action. A total of 520 patients aged ≥22 years will be enrolled, stratified by sex (1:1), and followed at the Heart Institute (InCor) of the University of São Paulo. Participants will be allocated into one of four protocol groups:

Group 1 - Pilot (n=15): Healthy volunteers monitored for ~14±3 days using both the smartwatch and a portable holter system to validate usability, skin tolerability, signal integrity, and data flow within the platform.

Group 2 - Extensive Outpatient Monitoring (n=150): Patients with chronic cardiovascular diseases monitored over a 45-day period. During 30 days, monitoring will be performed using a smartwatch to capture blood pressure, oxygen saturation, heart rate, and single-lead ECG. For 15 days, participants will use both the smartwatch (for HR and ECG) and a portable holter system.

Group 3 - Extensive Post-Intervention Monitoring (n=50): Patients recently undergoing procedures such as angioplasty, TAVI, or ablation, following the same monitoring protocol as Group 2.

Group 4 - Optimized Outpatient Monitoring (n=305): Patients with stable chronic cardiac disease monitored for 15±3 days, using both devices simultaneously for HR and ECG (smartwatch) and portable holter system.

Inclusion Criteria:

• Patients diagnosed with cardiovascular disease, of both sexes, aged over 22 years;
• Provision of informed consent through signature of the Informed Consent Form (ICF);
• Assentation to adhere to study procedures and requirements;
• Patients indicated for outpatient follow-up due to a cardiovascular condition, or with clinical parameters indicating the need for conventional surgical or catheter-based interventions (e.g., catheter ablation for arrhythmias, transcatheter aortic valve implantation, percutaneous coronary intervention, etc.);
• Low or no risk of skin injury, based on Braden Scale clinical criteria or clinical team assessment

Exclusion Criteria:

• Presence of skin conditions, such as vitiligo, lupus, or atopic dermatitis, as well as tattoos on the wrist that may interfere with the smartwatch's optical sensor readings;
• Known sensitivity or history of allergic reactions to components of the wearable devices or related items, such as adhesives or electrodes;
• Inability to properly use the wearable monitoring devices due to physical, cognitive, or technological limitations;
• Presence of a peripherally inserted central catheter (PICC) or arteriovenous fistula;
• Presence of implanted cardiac devices, such as pacemakers, defibrillators, or cardiac resynchronization devices, which prevent ECG acquisition via smartwatch;
• Diagnosis of conditions associated with narrowing or obstruction of the aorta and subclavian arteries (e.g., Stanford Type A chronic aortic dissection, Takayasu arteritis, Subclavian Steal Syndrome, or Kawasaki disease), which may cause discrepancies in blood pressure between upper limbs and interfere with study assessments.

Participant monitoring will be conducted by the multidisciplinary team via the SI³ platform, allowing near real-time detection of clinical events and prompt intervention. After study completion, all data will be anonymized and analyzed by the InCor team. De-identified datasets may be shared with the sponsor and affiliated entities. No personally identifiable information will be disclosed. All data sharing will comply with ethical and legal data protection standards.

Individual participant data (IPD) and supporting documentation will be made available exclusively to the study sponsor following the completion of the clinical study. There is no defined end date, as the sponsor will assume full custodianship of the data upon transfer. No public sharing of the data is planned.

Access to IPD and supporting information will be restricted to the study sponsor, in accordance with contractual agreements and applicable data protection regulations. The sponsor will have full authority over data access, management, and potential secondary use.

ECG Reader: The ECG reader will analyze the ECGs without access to identifiable participant information, ensuring that the interpretation of data is done blindly, without bias related to the patient's identity.

AI Model Developer: The developer will also work with anonymized data, meaning they will not have access to personal information of the participants, ensuring the integrity and confidentiality of the data during model development.