Hativ® Elektrokardiogramm-Überwachung bei Patienten mit Verdacht auf Arrhythmie (HELP-A)

Participants undergo continuous single-lead ECG monitoring with Memo Patch for up to 7 consecutive days and report symptom onset using a mobile messaging chatbot or paper diary.

Continuous single-lead ECG monitoring for up to 7 consecutive days. Participants report the onset of symptoms using a mobile messaging chatbot or paper diary. For each reported symptomatic episode, a 20-minute ECG segment extending from 10 minutes before to 10 minutes after the reported onset is available for review.

Participants use Hativ for 30 days and perform 10-second 6-lead ECG recordings at least twice daily and whenever symptoms occur.

Handheld ECG monitoring using 10-second 6-lead recordings obtained at least twice daily and additionally whenever symptoms occur for 30 days. Recordings are transmitted through the companion smartphone application to a secure study server.

Proportion of randomized participants with at least one participant-confirmed typical symptomatic episode documented with an interpretable ECG using the initially assigned device by the 1-month follow-up visit and before optional sequential monitoring. Primary-endpoint success comprises either a positive symptom-rhythm correlation or a negative-only symptom-rhythm correlation. A positive correlation is a qualifying symptomatic episode with an interpretable ECG showing a rhythm finding judged by central adjudication to be temporally and clinically concordant with that episode. A negative-only correlation requires at least one qualifying symptomatic episode with an interpretable ECG showing no concordant rhythm finding and no positive correlation by the 1-month visit.

Proportion of participants with at least one qualifying participant-confirmed typical symptomatic episode documented with an interpretable ECG showing a rhythm finding judged by central adjudication to be temporally and clinically concordant with that episode.

Proportion of participants with at least one qualifying participant-confirmed typical symptomatic episode documented with an interpretable ECG showing no temporally and clinically concordant rhythm finding and with no positive correlation by the 1-month follow-up visit.

Proportion of participants with at least one qualifying positive symptom-rhythm correlation and at least one qualifying negative symptom-rhythm correlation. This measure is descriptive.

Proportion of participants with at least one centrally adjudicated clinically significant arrhythmia detected during initially assigned-device monitoring, irrespective of symptom association. Clinically significant arrhythmias are classified using prespecified device-specific operational definitions. Findings are additionally classified as symptom-associated or not temporally associated with a qualifying typical symptomatic episode.

Rate and timing of arrhythmia-directed therapeutic interventions, including medication, catheter ablation, or cardiac device implantation.

Overall satisfaction with the initially assigned device is assessed using the Study-Specific Overall Device Satisfaction Rating, a single-item, five-point ordinal scale in the 1-month participant questionnaire. Responses are scored as 1 = very dissatisfied, 2 = dissatisfied, 3 = neither satisfied nor dissatisfied, 4 = satisfied, and 5 = very satisfied. The minimum possible score is 1 and the maximum is 5, with higher scores indicating greater satisfaction, a more favorable outcome. The item is assessed separately from device-specific usability questions and willingness to recommend the device.

Change in the EQ-5D-5L index score from enrollment to the 1-month follow-up visit.

Arrhythmia-related healthcare resource use through 3 months, including additional diagnostic tests, arrhythmia-related medications, emergency department visits, and hospitalizations. Costs are derived from institutional billing records at participating centers and expressed in Korean won. The base-case analysis excludes acquisition cost of the study devices because the devices were supplied in kind.

Number and percentage of participants who experience at least one device-related adverse event or at least one serious adverse event through 3 months after randomization. Expected device-related adverse events include skin irritation or contact dermatitis associated with the adhesive patch and discomfort associated with device use. Serious adverse events are included regardless of their relationship to the study device. Each participant is counted once for this outcome, irrespective of the number of qualifying events experienced

Among participants who undergo optional sequential monitoring with both study devices, paired evaluations are collected using the Study-Specific Three-Month Head-to-Head Device Evaluation Questionnaire.

Device usability is assessed separately for each device using eight items. Each item is scored from 1 (very difficult) to 5 (very easy), with 2 = difficult, 3 = neither difficult nor easy, and 4 = easy. The minimum possible score for each item is 1 and the maximum is 5; higher scores indicate better perceived usability. "Not applicable" responses are recorded separately and are not assigned a numerical score. Usability items are reported individually rather than combined into a total score.

Overall satisfaction with each device is assessed using a single five-point ordinal item, scored from 1 (very dissatisfied) to 5 (very satisfied), with 2 = dissatisfied, 3 = neither satisfied nor dissatisfied, and 4 = satisfied. The minimum possible score is 1 and the maximum is 5; higher scores i