How home devices can support early detection of atrial fibrillation (AF)

When caring for patients with potential cardiac issues, the speed of a diagnosis can make all the difference. That is especially the case when we are talking about AF, which often goes undetected until a stroke or some other catastrophic outcome occurs.^1,2 Early detection of undiagnosed AF reduces stroke risk and facilitates long-term maintenance of sinus rhythm.^2,3,4 The recent emergence of commercially available home blood pressure (BP) devices with AF detection algorithms has provided a rich opportunity to screen a larger asymptomatic population.

Tracking At-Risk Patients

A 2023 retrospective cohort study estimated that in the United States (U.S.), 11% of cases of AF were undiagnosed; the two-year prevalence of silent AF was estimated at 23%.⁵

Most clinicians have faced the same dilemma: paroxysmal and subclinical AF are a diagnostic challenge because patients may not manifest an arrhythmia while being screened with one-off tests.⁶ A routine physical exam or 12-lead electrocardiogram (ECG) may not satisfy the clinician that AF has been ruled out in their patient.⁷ Even Holter monitors and event (loop) monitors have a low yield for diagnosis: 2.2% with a 24-hour Holter monitor, and with loop monitors, the yield is about 7.4% at 1 week, 11.6% at 2 weeks, 12.3% at 3 weeks, and 14.8% at 4 weeks.⁸ Thus, a potentially life-threatening arrhythmia continues undiagnosed and untreated.

New technology in the form of home BP monitors with an AF screening device provides clinicians with a novel and convenient way to help identify occult AF. The utility of these devices is enhanced by BP monitoring; a large body of evidence shows that home BP is a better prognosticator than office BP and is an important predictor of cardiovascular disease (CVD),  as well as stroke-related morbidity and mortality.⁹

Numerous factors further tie together BP and AF, such as:^10,11,12,13

• Hypertension (htn) is the most common AF cardiovascular comorbidity;

• Htn leads to left atrial alterations that predispose to AF;

• Both are associated with autonomic and renin-angiotensin-aldosterone (RAA) dysfunction;

• Htn is associated with a 1.8-fold increase in AF and a 1.5-fold increase in progression to permanent AF; and

• Htn is a risk factor for bleeds in anticoagulated patients.

AF-enabled BP monitors make sense. But, do these devices work? And do they affect clinical outcomes?

The Evidence

A large (n = 1000) 2014 head-to-head study found that in the primary care setting, BP devices with AF detection algorithms are a better triage test than single-lead ECG monitors.⁷

A 2019 literature review and meta-analysis concluded that automated oscillometric BP measurements appear to be clinically relevant in AF, providing similar associations with intra-arterial BP measurements as in patients without AF; and screening for AF in the elderly using an AF-specific BP monitor during office or ambulatory BP measurement has a high diagnostic accuracy.¹⁴

A large (n = 559) 2024 clinical trial evaluated two home BP monitors (BPMs) with a novel AF screening algorithm (the HEM-7371T1-AZ and HEM-7372T1-AZAZ devices from OMRON Healthcare).¹⁵ All study subjects were screened using the OMRON devices. Twelve-lead ECGs were taken concurrently for comparison and read by a cardiologist blinded to the BPM readings. The OMRON HEM-7371T1-AZ device was found to have a sensitivity of 95.1%, specificity of 98.6%, and accuracy of 97.0% for the detection of AF. The OMRON HEM-7371T1-AZAZ produced similar results. The study authors concluded that “These data support both home and professional use of these novel OMRON BPMs for detecting AF.”¹⁵

The Risks of Undiagnosed AF

Evidence suggests that occult AF is present in 30% of cryptogenic strokes (i.e., strokes with no known cause) and that it is causative in 41.2% of those cases.^2,16

AF is associated with cardiomyopathy (ischemic, nonischemic, hypertrophic, and infiltrative) and is a major risk factor for new-onset heart failure. It has also been associated with dementia, reduced quality of life (QoL), and, particularly in those with heart failure, all-cause mortality.^8,17 Given that AF is a modifiable risk factor when diagnosed and treated, the onus is on clinicians to maintain a high degree of clinical surveillance.

The Convenience

The OMRON line of AF-enabled BP monitors provides a novel and convenient modality for detecting AFib in patients.

At-home patients can keep their healthcare provider “in the loop” through the OMRON connect app, which allows them to share their data.

At-home use costs are more than negated by lessening the need for appointments, which cuts down on travel time and costs for the patient. The value of reducing the risk of a stroke and other effects of undiagnosed and untreated AF is incomparable.

Consider adding OMRON BP devices with AF detection algorithms to your practice, whether in-office or for patients’ at-home use.

By Andrew Proulx, MD