Table 2.

Studies Focused on AF Screening and Their Outcomes

Study	Participants (Number)	Intervention	Outcome
Prevalence of Sub-Clinical Atrial Fibrillation Using and Implantable Cardiac Monitor (ASSERT-II) (NCT01694394)	65 years and older with an increased risk of AF and cardiovascular events but without prior history of AF or implanted pacemaker or defibrillator (n = 256)	ICM	Frequent detection of subclinical AF
Incidence of AF in High-Risk Patients (REVEAL AF) (NCT01727297)	18 years and older with a CHADS2 score ≥3 (or 2 with at least 1 additional risk factor)(n = 446)	Reveal ICM	AF remains undetected in patients monitored less than 30 days, ICMs can detect AF episodes which cannot be found with conventional short-term monitoring strategies.
Atrial Fibrillation Detected by Continous ECG Monitoring (LOOP) (NCT02036450)	70-90 years olds with at least 1 additional stroke risk factor but without prior history of AF (n = 6000)	ILR	ILR screening resulted in a 3-time increase in AF detection in individuals with stroke risk factors.
Systematic ECG Screening for Atrial Fibrillation Among 75-Year-Old Subjects in the Region of Stockholm and Halland, Sweden (STROKESTOP) (NCT01593553)	75-76 years olds (n = 7173)	ECG screening for AF using intermittent ECG recorder	The use of intermittent ECGs increased new AF detection 4-fold indicating that screening is safe and beneficial in older populations.
Assessment of Remote Heart Rhythm Sampling Using the AliveCor Heart Monitor to Screen for Atrial Fibrillation: The REHEARSE-AF Study	65 years and older with a CHADS-VASc score ≥2(n = 1001)	AliveCor Kardia monitor attached to a WiFi-enabled iPod to obtain ECGs (iECGs)	iECG screening is very effective in identifying incident AF cases in patients ≥65 years of age with an increased risk of stroke.
Home-Based Screening for Early Detection of Atrial Fibrillation in Primary Care Patients Aged 75 Years and Older (SCREEN-AF) (NCT02392754)	75 years and older with hypertension and without known AF (n = 856)	Screening: Intervention-AF screening (ECG patch monitor)	Screening with a ECG patch monitor among older patients with hypertension led to a 10-fold increase in AF detection.
The Apple Heart Study (NCT03335800)	22 years and older without AF (n = 419 297)	Smartphone application and ECG patch monitor	Among participants who had an irregular pulse notification, 34% had AF on subsequent ECG patch readings and 84% of notifications were concordant with AF. Irregular pulse notification rate is significantly higher in ≥65 years old.
The Huawei Heart Study	18 years and older (n = 644 124)	PPG-based smart devices	The positive predictive value of detecting AF was 91.6% with periodic measurements in every 10 minutes.
The Fitbit Heart Study (NCT04380415)	22 years and older without AF (n = 644 124)	PPG-based smart devices and ECG patch monitor	Analysis is in progress.
Prevalence of Sub-Clinical Atrial Fibrillation Using and Implantable Cardiac Monitor (ASSERT-II)	NCT01694394	Implantable cardiac monitor	Detection rate for subclinical AF ≥5 minutes 34.4%/y (95% CI, 27.7-42.3)
Incidence of AF in High-Risk Patients (REVEAL AF)	NCT01727297	Reveal implantable cardiac monitor	The detection rate of AF lasting 6 or more minutes at 18 months was 29.3%. Detection rates at 30 days and 6, 12, 24, and 30 months were 6.2%, 20.4%, 27.1%, 33.6%, and 40.0%, respectively.
Atrial Fibrillation Detected by Continous ECG Monitoring (LOOP)	NCT02036450	Implantable loop recorder	A single 10-second ECG yielded a sensitivity (and negative predictive value) of 1.5% (66%) for AF detection, increasing to 8.3% (67%) for twice-daily 30-second ECGs during 14 days and to 11% (68%), 13% (68%), 15% (69%), 21% (70%), and 34% (74%) for a single 24-hour, 48-hour, 72-hour, 7-day, or 30-day continuous monitoring, respectively.
Systematic ECG Screening for Atrial Fibrillation Among 75-Year-Old Subjects in the Region of Stockholm and Halland, Sweden (STROKESTOP)	NCT01593553	ECG screening for atrial fibrillation using intermittent ECG recorder	AF was found in 0.5% of the screened population on their first ECG. The use of intermittent ECGs increased new AF detection 4-fold. A previous diagnosis of AF was known in 9.3% (n = 666; 95% CI, 8.6-10.0). Total AF prevalence in the screened population was 12.3%.
Assessment of Remote Heart Rhythm Sampling Using the AliveCor Heart Monitor to Screen for Atrial Fibrillation: The REHEARSE-AF Study	N/A	AliveCor Kardia monitor attached to a WiFi-enabled iPod to obtain ECGs (iECGs)	19n patients in the iECG group were diagnosed with AF over the 12-month study period vs 5 in the RC arm (hazard ratio, 3.9; 95% CI = 1.4-10.4; P  = .007) at a cost per AF diagnosis of $10 780 (£8255).
Home-Based Screening for Early Detection of Atrial Fibrillation in Primary Care Patients Aged 75 Years and Older (SCREEN-AF)	NCT02392754	Screening: Intervention-AF screening (ECG patch monitor)	AF was detected in 5.3% in the screening group vs. 0.5% in the control group (relative risk, 11.2; 95% CI, 2.7-47.1; P  = .001; absolute difference, 4.8%; 95% CI, 2.6%-7.0%; P  < .001; number needed to screen, 21). Twice-daily AF screening using the home BP monitor had a sensitivity of 35.0% (95% CI, 15.4%-59.2%), specificity of 81.0% (95% CI, 76.7%-84.8%), positive predictive value of 8.9% (95% CI, 4.9%-15.5%), and negative predictive value of 95.9% (95% CI, 94.5%-97.0%).

PPG, photoplethysmography; ILR, implantable loop recorder; ICM, implantable cardiac monitor; AF, atrial fibrillation; RC, routine care; ECG, electrocardiogram. AF, atrial fibrillation; BP, blood pressure; ECG, electrocardiogram.