Subclinical Atrial Fibrillation Home Monitoring in Hypertensive Patients

The BP/AF Mode study is a multicenter, observational, prospective, cohort trial involving 25 researchers from six countries: Argentina, Chile, Colombia, Ecuador, Mexico, and Peru. The study was submitted to the IASC Academia (Inter-American Society of Cardiology) and approved under Project File Number 052, dated January 29, 2025. It will be conducted in full compliance with the World Medical Association Codes of Ethics for experiments involving human subjects.

The study aims to include hypertensive patients with no history of atrial fibrillation who are at moderate or high risk of suffering from this arrhythmia according to the HARMS2-AF score or the modified Taiwan AF . The diagnosis of hypertension is supported on the 2023 European Society of Hypertension Guidelines. The patients' baseline characteristics are entered into an interactive web platform, and after that the practitioners received information about cardiovascular risk (Hearts score, Score-2 and Score-OP), Frailty index and atrial fibrillation risk (HARMS2-AF score and modified Taiwan AF score).

After the screening visit, if the patient meets all the inclusion criteria and does not present exclusion criteria, he or she is included in the study and a Omron Complete Hem-7530 T ECG device (Omron Healthcare Co., Ltd., Japan) device is delivered.

The 30-second home ECG tracings will be obtained using the Omron Complete Hem-7530 T ECG device (Omron Healthcare Co., Ltd., Japan). The connection and smartphone app download will be available from Omron Connect free of charge on the Google Play Store: https://play.google.com/store/apps/details?id=jp.co.omron.healthcare.omron_connect\&hl=es_419\&pli=1 and on the iOS App Store: https://apps.apple.com/mx/app/omron-connect/id1003177043. Two duplicate ECG recordings will be required daily: the first in the morning before breakfast and taking the prescribed medication, and another in the evening before dinner and taking the afternoon/evening medication. Additional ECG recordings will be required if the patient experiences any symptoms. The study investigator will work with the patient to download the app and perform the first electrocardiogram tracing and transmit it to the database. The patient will be given instructions on how to correctly perform the ECG and transmit it to the platform, along with a patient diary. Simultaneously with obtaining the ECG tracings, the patient will take two BP measurements, in a seated position, separated by one minute, following the recommendations of the Latin American Society of Hypertension guidelines. After 1 week, the patient will return the device to the research center. A recording will be considered valid when at least 80% of the ECG tracings and BP measurements are valid.

Statistical analysis Considering those patients with a modified Taiwan AF score > 5 points, whose annual incidence of atrial fibrillation ranges between 1.54% and 6.98%, or a HARMS2-AF score > 7 points, whose annual incidence of atrial fibrillation ranges between 1.35% and 6.62%, it will be required to include 499 patients to achieve a 5% margin of error, with a 99% confidence level. If the sample calculation does not achieve the expected results, recruitment will continue until 25 cases of atrial fibrillation are reached.

Continuous variables will be reported as means with their standard deviations for normally distributed variables, or median and interquartile range for non-normally distributed variables. Discrete variables will be reported as absolute values and percentages. Unpaired ANOVA will be used to analyze normally distributed variables, while the Kruskal-Wallis test will be used for non-normally distributed variables. Differences in proportions will be assessed using the Chi-square test. A two-tailed p-value < 0.05 will be considered statistically significant.