This study investigates whether a smartphone application that measures heart rhythm using light, a technique known as photoplethysmography or PPG, can accurately detect when the cardiac arrhythmia atrial fibrillation (AF) spontaneously terminates and the heart returns to normal sinus rhythm. This is a prospective, multicentre randomised controlled study conducted at Hospital East Limburg and University Hospitals Leuven. Continuous heart rhythm monitoring with conventional equipment is often not feasible in the home setting because of the high cost and complexity of the equipment. Smartphone-based PPG monitoring offers a practical and affordable alternative. The study will include 200 adult patients with known AF who are scheduled for elective electrical cardioversion. Patient will be randomised to either standard of care (no remote monitoring) or smartphone-based PPG monitoring. During the seven days preceding the procedure, participants in the intervention group will perform PPG and ECG measurements at predefined times using their smartphone and a chest strap. The primary objective is to determine whether this intermittent, app-guided monitoring can detect spontaneous conversion to normal sinus rhythm before the planned cardioversion, thereby preventing unnecessary hospital admissions. In addition, we will evaluate the relationship between symptoms and cardiac rhythm, adherence to and user experience with self-monitoring, and the predictive value of the measured parameters for recurrence of AF or atrial flutter during one year of follow-up.
Study Type
INTERVENTIONAL
Allocation
RANDOMIZED
Purpose
HEALTH_SERVICES_RESEARCH
Masking
NONE
Enrollment
200
Twice daily smartphone-based PPG monitoring during 7 days before planned admission for electrical cardioversion
Ziekenhuis Oost Limburg
Genk, Limburg, Belgium
University Hospitals Leuven
Leuven, Vlaams-Brabant, Belgium
Cancellation of planned admission for electrical cardioversion.
Cancellation of planned admission for electrical cardioversion.
Time frame: From date of randomization until the initial date of planned admission for electrical cardioversion, assessed up to 8 weeks.
Spontaneous reconversion rate
Defined as the rate of patients having at least one ECG measurement in sinus rhythm before planned cardioversion.
Time frame: From date of randomization until the initial date of planned admission for electrical cardioversion, assessed up to 8 weeks.
Cost analysis of systematic PPG monitoring prior to cardioversion.
Cost analysis of systematic PPG monitoring prior to cardioversion.
Time frame: From date of randomization until the initial date of planned admission for electrical cardioversion, assessed up to 8 weeks.
AF or Aflutter recurrence rate post-cardioversion
AF or Aflutter recurrence rate during 30 days post-cardioversion
Time frame: from planned admission until 30 days afterwards
AF or Aflutter recurrence rate during 1 year follow-up.
AF or Aflutter recurrence rate during 1 year follow-up.
Time frame: From planned admission until 1 year of follow-up.
Time to AF or Aflutter recurrence.
Time to AF or Aflutter recurrence.
Time frame: From planned admission until 1 year of follow up
Electrical cardioversion rate during 1 year follow-up.
Electrical cardioversion rate during 1 year follow-up.
Time frame: From planned admission until 1 year of follow-up.
Hazard ratio for AF or atrial flutter recurrence per 10-point increase in the AI-enabled ECG-derived AF risk score
The AI-enabled ECG-derived atrial fibrillation risk score will be calculated from a standard 12-lead ECG recorded in sinus rhythm. The score ranges from 0 to 100, with higher scores indicating a higher estimated risk of atrial fibrillation. Recurrence will be defined as documented atrial fibrillation or atrial flutter occurring after the planned admission date. Cox proportional-hazards regression will be used to estimate the hazard ratio for time to first AF or atrial flutter recurrence per 10-point increase in the AI-derived risk score.
Time frame: AI-ECG score assessed using the prespecified sinus-rhythm ECG. Recurrence assessed through one year after planned admission
Odds ratio for spontaneous reconversion per 10-point increase in the AI-enabled ECG-derived AF risk score
The AI-enabled ECG-derived atrial fibrillation risk score will be calculated from the most recent standard 12-lead ECG recorded in sinus rhythm. The score ranges from 0 to 100, with higher scores indicating a higher estimated risk of atrial fibrillation. Spontaneous reconversion will be defined as documented restoration of sinus rhythm before the planned admission for electrical cardioversion. Logistic regression will be used to estimate the odds ratio for spontaneous reconversion per 10-point increase in the AI-derived risk score.
Time frame: AI-ECG score assessed using the last available sinus-rhythm ECG before date of randomization. Spontaneous cardioversion assessed from date of randomization until the initial date of planned admission for electrical cardioversion, assessed up to 8 weeks.
Prediction analysis for spontaneous conversion to sinus rhythm before admission.
Prediction analysis for spontaneous conversion to sinus rhythm before admission.
Time frame: From date of randomization until the initial date of planned admission for electrical cardioversion, assessed up to 8 weeks.
Prediction analysis for AF/Aflutter recurrence during one year follow-up.
Prediction analysis for AF/Aflutter recurrence during one year follow-up.
Time frame: From enrollment until one year of follow-up after planned admission.
Patient-reported AFEQT overall score and domain scores at baseline and 30-day follow-up.
Patient-reported AFEQT overall score and domain scores at baseline and 30-day follow-up.
Time frame: From enrollment until 30 days of follow-up after planned admission.
The accuracy of smartphone-based PPG monitoring in detecting spontaneous reconversion of AF in patients planned for electrical cardioversion
The accuracy of smartphone-based PPG monitoring in detecting spontaneous reconversion of AF in patients planned for electrical cardioversion will be evaluated by calculating key performance metrics such as sensitivity, specificity, positive predictive value, and negative predictive value. For each participant all AF, Aflutter and sinus rhythm episodes identified by the PPG system automatic algorithm, as well as blinded cardiologist's interpretation will be compared against those recorded by a simultaneous single lead or 12 lead ECG. The concordance between these methods, as determined by two independent, blinded cardiologists will assess the PPG system's ability to accurately classify AF, Aflutter and sinus rhythm events.
Time frame: From date of randomization until the initial date of planned admission for electrical cardioversion, assessed up to 8 weeks.
Paroxysmal AF detection rate
Defined as the rate of patients having at least one ECG measurement in AF/Aflutter after experiencing spontaneous reconversion during the monitoring period.
Time frame: From date of randomization until the initial date of planned admission for electrical cardioversion, assessed up to 8 weeks.
Missed AF or Aflutter event rate using PPG monitoring.
This will be reported as the amount of simultaneous AF/AFlutter ECG and sinus rhythm PPG recording pairs divided by the total AF/AFlutter ECG recordings.
Time frame: From date of randomization until the initial date of planned admission for electrical cardioversion, assessed up to 8 weeks.
Other arrhythmia detected by single lead ECG.
The rates of each arrhythmia will be reported.
Time frame: From date of randomization until the initial date of planned admission for electrical cardioversion, assessed up to 8 weeks.
Conversion rate to other type of atrial arrhythmia (Atrial tachycardia, atrial flutter or AF).
This will be defined as the rate of patients having at least one ECG measurement showing a different atrial arrhythmia than the atrial arrhythmia at inclusion during the monitoring period.
Time frame: From date of randomization until the initial date of planned admission for electrical cardioversion, assessed up to 8 weeks.
Mean absolute difference between PPG-derived and ECG-derived heart rate
Heart rate will be measured simultaneously using smartphone photoplethysmography and a single-lead ECG. For each paired measurement, the absolute difference between the heart rate reported by the PPG measurement and the heart rate reported by the ECG measurement will be calculated as: Absolute heart-rate difference = PPG heart rate - ECG heart rate The mean absolute difference across all evaluable paired measurements will be reported.
Time frame: From date of randomization until the initial date of planned admission for electrical cardioversion, assessed up to 8 weeks.
Symptom rate during rhythm assessments.
This will be reported as the percentage of measurements where symptoms have been indicated, the percentage of measurements where no symptoms have been indicated, the percentage of AF/Aflutter measurements where
Time frame: From enrolment until 30 days after planned admission.
Correlation analysis of clinical parameters and symptomatic AF/Aflutter recording rate as well as the SRC index.
Correlation analysis of clinical parameters and symptomatic AF/Aflutter recording rate as well as the SRC index.
Time frame: From enrolment until 30 days after planned admission.
Weekly alcohol consumption
Self-reported alcohol consumption will be assessed using a study-specific questionnaire at baseline, on admission for electrical cardioversion, and at the 30-day follow-up. At each assessment, participants will report the number of standard alcoholic units consumed during a typical week. One standard alcoholic unit will be defined as (one glass of wine, one beer, or one shot/measure of spirits). Alcohol consumption will subsequently be compared between participants with and without documented recurrence of atrial fibrillation or atrial flutter within one year.
Time frame: From enrollment until one year follow up after planned admission. Recurrence status assessed through one year
Number of days with alcohol consumption per week
The frequency of alcohol consumption will be assessed using a study-specific questionnaire at baseline, on admission for electrical cardioversion, and at the 30-day follow-up. At each assessment, participants will report the number of days during a typical week on which they consume alcohol. Alcohol-consumption frequency will subsequently be compared between participants with and without documented recurrence of atrial fibrillation or atrial flutter within one year.
Time frame: From enrolment until 30 days of follow-up. Recurrence status assessed through one year.
Weekly caffeine consumption
Self-reported caffeine consumption will be assessed using a study-specific questionnaire at baseline, on admission for electrical cardioversion, and at the 30-day follow-up. At each assessment, participants will report their consumption of caffeinated beverages during a typical week. A caffeinated beverage will be defined as a cup of coffee (one standard cup/mug of caffeinated coffee) or a caffeinated drink other than coffee (one cup/glass/can/bottle of tea, cola, energy drink, etc). Caffeine consumption will subsequently be compared between participants with and without documented recurrence of atrial fibrillation or atrial flutter within one year.
Time frame: From enrolment until 30-days of follow up. Recurrence status assessed through one year.
Number of days with caffeine consumption per week
The frequency of caffeine consumption will be assessed using a study-specific questionnaire at baseline, on admission for electrical cardioversion, and at the 30-day follow-up. At each assessment, participants will report the number of days during a typical week on which they consume caffeinated beverages. Caffeine-consumption frequency will subsequently be compared between participants with and without documented recurrence of atrial fibrillation or atrial flutter within one year.
Time frame: From enrolment until 30-days of follow up. Recurrence status assessed through one year.
Odds ratio for spontaneous reconversion per additional weekly alcohol unit at enrollment
Alcohol consumption will be assessed at enrollment using a study-specific questionnaire. Participants will report the number of standard alcoholic units consumed during a typical week. One standard alcoholic unit will be defined as (one glass of wine, one beer, or one shot/measure of spirits). Spontaneous reconversion will be defined as documented restoration of sinus rhythm before the planned admission for electrical cardioversion. Logistic regression will be used to estimate the odds ratio for spontaneous reconversion per additional alcoholic unit consumed per week.
Time frame: Alcohol consumption assessed at enrollment. Spontaneous reconversion assessed from date of randomization until the initial date of planned admission for electrical cardioversion, assessed up to 8 weeks.
Odds ratio for spontaneous reconversion per additional day of alcohol consumption per week at enrollment
Frequency of alcohol consumption will be assessed at enrollment using a study-specific questionnaire. Participants will report the number of days during a typical week on which they consume alcohol. Spontaneous reconversion will be defined as documented restoration of sinus rhythm before the planned admission for electrical cardioversion. Logistic regression will be used to estimate the odds ratio for spontaneous reconversion per additional day of alcohol consumption per week.
Time frame: Alcohol consumption frequency assessed at enrollment. Spontaneous reconversion assessed from date of randomization until the initial date of planned admission for electrical cardioversion, assessed up to 8 weeks.
Odds ratio for spontaneous reconversion per additional weekly caffeine serving at enrollment
Caffeine consumption will be assessed at enrollment using a study-specific questionnaire. Participants will report the number of standard servings of caffeinated beverages consumed during a typical week. A caffeinated beverage will be defined as a cup of coffee (one standard cup/mug of caffeinated coffee) or a caffeinated drink other than coffee (one cup/glass/can/bottle of tea, cola, energy drink, etc). Spontaneous reconversion will be defined as documented restoration of sinus rhythm before the planned admission for electrical cardioversion. Logistic regression will be used to estimate the odds ratio for spontaneous reconversion per additional caffeinated serving consumed per week.
Time frame: Caffeine consumption assessed at enrollment. Spontaneous reconversion assessed from date of randomization until the initial date of planned admission for electrical cardioversion, assessed up to 8 weeks.
Odds ratio for spontaneous reconversion per additional day of caffeine consumption per week at enrollment
Frequency of caffeine consumption will be assessed at enrollment using a study-specific questionnaire. Participants will report the number of days during a typical week on which they consume caffeinated beverages. Spontaneous reconversion will be defined as documented restoration of sinus rhythm before the planned admission for electrical cardioversion. Logistic regression will be used to estimate the odds ratio for spontaneous reconversion per additional day of caffeinated beverage consumption per week.
Time frame: Caffeinated beverage consumption frequency assessed at enrollment. Spontaneous reconversion assessed from date of randomization until the initial date of planned admission for electrical cardioversion, assessed up to 8 weeks.
Patient adherence with self-monitoring.
Adherence to smartphone-based self-monitoring will be calculated for each participant as the number of completed scheduled recordings divided by the total number of scheduled recordings during the prescription period, multiplied by 100. The mean or median participant-level adherence percentage will be reported.
Time frame: From enrolment until 30 days after planned admission
Patient motivation with self-monitoring.
Motivation will be calculated for each participant as the number of prescribed monitoring days on which at least two scheduled recordings were completed divided by the total number of prescribed monitoring days, multiplied by 100. The mean or median participant-level percentage of adherent monitoring days will be reported.
Time frame: From enrolment until 30 days after planned admission.
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