This study aims to develop a digitally assisted telemonitoring platform using the Samsung TM Galaxy Watch5 smartwatch, validating the applicability of the solution in patients with POAF (Postoperative Atrial Fibrillation), along with the accuracy of the smartwatch in detecting vital signs through optical sensors and possibly identifying irregularities in heart rhythm. The validation of its applicability will be carried out through a clinical trial. This is a randomized observational pilot study resulting from the partnership established in the base year of 2022 between InCor and Samsung.

The sample consisted of 108 outpatient patients with cardiac diseases who underwent cardiac surgery and were selected during the preoperative consultation. Subsequently, the patients were randomized (1:1) into the intervention group (teleassisted group) or the control group (standard institution follow-up).

The sample size was proposed by the contracting party as this is a pilot study to assess whether the implementation of a technological solution assists in monitoring and predicting the risk of surgical patients in the postoperative phase, as well as the accuracy of the Samsung TM Galaxy Watch5 smartwatch in a sample with POAF.

This interventional study was conducted exclusively at the Heart Institute of the Clinics Hospital of the Medical School of the University of São Paulo (InCor - HCFMUSP). It was a single-center study divided into six phases.

The first phase involved outpatient preoperative care, where patients underwent a comprehensive anamnesis during the preoperative consultation and were informed about the study. In the second phase, patients were hospitalized and provided with the Informed Consent Form (ICF) if they met the inclusion criteria. Demographic data were collected during this phase.

During the surgical phase (third phase), intraoperative data were collected after cardiac surgery. The fourth phase focused on postoperative care, where patients were evaluated, and health measures such as blood pressure (BP), heart rate (HR), electrocardiogram (ECG), and peripheral oxygen saturation (SpO2) were collected using the SAMSUNGTM Galaxy Watch5 smartwatch and reference devices.

After discharge, the fifth phase involved a 30-day telemonitoring period, where patients were remotely monitored using the smartwatch. Health data, including BP, HR, ECG, and SpO2, were collected three times a day during this phase. The medical team provided clinical interventions when alerts were received via the "FAPO SI³" platform.

In the final phase, patients returned for an outpatient visit at InCor, where health measures were collected again using the smartwatch and reference devices. Additionally, a World Health Organization Quality of Life (WHOQOL) questionnaire was administered to assess patients' quality of life. ECG reports issued by the smartwatch were also reviewed.

The control group consisted of patients with heart disease who underwent surgical procedures and received standard outpatient and post-surgical follow-up according to institutional routines and protocols.

Overall, the study aimed to develop and validate an assisted digital telemonitoring platform for patients with postoperative atrial fibrillation (POAF). The telemonitored group used the SAMSUNGTM Galaxy Watch5 smartwatch for remote monitoring, while the control group followed standard care protocols.

Inclusion Criteria:

• Age ≥ 22 years;
• Parameters for surgical indication, in the presence of heart disease (mitral or aortic valve disease, coronary artery disease or aortic disease);
• Agree to adhere to the study's procedures and requirements;
• Be able to consent to their participation in writing;

Exclusion Criteria:

• Not having undergone cardiac surgery;
• Presence of post-surgical complications with prolonged hospital stay for more than 14 days from surgery date;
• Presence of a Peripherally Inserted Central Catheter (PICC) or limb preservation and cardiac pacemaker in case of impediment to acquisition of the ECG (smartwatch);
• Patients with arteriovenous fistula;
• Presence of skin pathology or skin diseases such as vitiligo, lupus and atopic dermatitis, as well as tattoos in the wrist region, which may interfere with the reading by the optical sensor;
• Show sensitivity or allergic reactions, to any degree, to the component materials of the wearable device;

During the 30-day telemonitoring period in the TLM (Telemonitoring) group, the ECG report evaluator was blinded to the patient's clinical condition and the presence of underlying atrial fibrillation (AF).

This masking approach was adopted to ensure that the evaluator was not influenced by prior clinical information or knowledge of the presence of AF before analyzing the ECG results provided by the smartwatch. The objective is to ensure impartiality and objectivity in the evaluation of the data obtained during the telemonitoring period.

By keeping this information hidden from the evaluator, a more unbiased and accurate analysis of the results can be achieved, without the influence of prior knowledge about the patient's clinical condition or the presence of AF. This contributes to ensuring the validity and reliability of the results obtained through smartwatch telemonitoring in the TLM group.