Over the next decade, the incidence of atrial fibrillation (AF)1 is expected to rise to 12.1 million.2 With a related increased risk of stroke and heart failure,3 “Screening for AF has gained substantial attention in recent years as several studies have demonstrated that screening is feasible,”4 according to researcher Shaan Khurshid. Making the case for a new vital sign, however, is complex.
It will take time for the United States (US) to update physical assessment practices and policies. Healthcare professionals will require criteria to identify which asymptomatic patients should be screened for AF and establish a systematic approach that is integrated with a clear pathway to care. To gain a greater understanding of the value of early detection, research in the area is ongoing. Physicians and scientists are building clinical evidence and leading the way in care advancement.
In the US, no official guidance for asymptomatic AF5— also known as silent AF or subclinical AF —screening exists. Conversely, the European Society of Cardiology (ESC) deems AF screening essential and recommends “opportunistic screening for those 65+ and systematic screening for those 75+.”6
Because screening a broad population is not cost-effective, the most at-risk patients should be better defined and identified based on clinical risk factors. The mobile health Screening To Prevent Strokes (mSToPS)7 trial found three primary reasons why targeted AF screening would be beneficial to patients:
Establishing guidelines for AF screening is an important step on the path to achieving vital sign status. To positively impact patient care, however, health plans need a method for identifying the right patients to screen, and providers (most notably primary care physicians) need turnkey solutions and efficient care pathways for managing at-risk patients.
The best way to identify and characterize the most at-risk patients is a topic of debate in the medical community. In some cases, physicians use the CHA2DS2-VASc score,10 but, in many circles, this vascular scoring system is thought to be an insufficient way to capture high AF risk — especially in patients with non-valvular AF.11 In fact, the ESC states that “CHA2DS2-VASc performs only modestly at predicting high-risk patients.”12
It would likely be beneficial for relevant medical societies to join the conversation and offer input on shaping AF screening guidelines and standards for identifying at-risk patients. Once screening guidelines have been established, payers and health managers will need a practical way of applying them to their specific patient populations. One method could utilize data mining to automate the process of identifying high-risk patients to screen. According to Steinhubl et al., “The use of digital technologies, including wearable sensors and large health record data sets allowing for targeted outreach toward individuals at increased risk for AF, might allow for unprecedented opportunities for effective, economical screening.”13 After the most at-risk patients are identified, then healthcare providers could screen with the appropriate cardiac monitoring solution, such as the Zio Service.
When AF is detected in a patient, primary care physicians in the US may need more efficient ways of collaborating with cardiologists than using traditional care pathways. Researchers in the Netherlands determined that general practitioners are increasingly inclined to use ECG to detect AF in their high-risk patients; they also outlined the following changes that could enhance collaboration between the disciplines: “To increase diagnostic accuracy and improve adequate patient referral using ECG screening in the general practitioner’s office several measures can be taken. First and foremost, lowering the threshold for interaction between general practitioner and cardiologist. This is increasingly facilitated by digital platforms and local partnerships. The general practitioner sends ECGs that are difficult to interpret to the cardiologist, who reviews the ECGs and provides diagnostic and therapeutic advice. Furthermore, these local and/or national partnerships need to address other topics such as education, screening indication and referral guidelines.”14
Without a systematic approach to AF screening, patients will (and are) taking matters into their own hands. The fourth quarter of 2020 saw a record demand for connected consumer wearables, according to research firm IDC, and growth has continued into 2021, with a 34% year-over-year increase during the first quarter.15
Yet, these well-intentioned, direct-to-consumer products fail to integrate with systems of care that at-risk patients need to diagnose, treat, and manage their condition effectively. Additionally, without the regulatory oversight and quality systems that medical-grade diagnostics are held accountable to, consumer wearables require the patients to bear more risk. “There are significant challenges such as lack of outcomes data, false positives, and concerns with data privacy requiring more research as well as collaboration of regulatory bodies and technology companies to support the implementation of mobile technology in cardiovascular disease prevention and management,”16 according to the study, "How useful is the smartwatch ECG?"
When a consumer-level mobile health (mHealth) device gives the wearer an irregular rhythm notification, that individual might send a rhythm strip to their physician. For physicians, an inherent clinical responsibility means the requests can’t be ignored. However, there is no clear current procedural terminology (CPT) code to bill for such interpretations. In addition, most consumer-grade ECG monitors presently require a smartphone, which can be cost prohibitive for the masses. Furthermore, technical complexity could hinder proper usage.
The Framingham Study showed AF is attributable to a fivefold increase in stroke risk,17 and Neuro News estimates the annual direct cost of stroke in the US is $35 billion.18 To avoid both burdens, AF screening should be considered for inclusion among the standard physiological data collected during health assessments at the primary care level.
A recent study in Ireland regarding the viability of opportunistic screening — from cost and practicality perspectives — concluded, “Annual opportunistic screening of men and women aged 65 years and older in primary care in Ireland is likely to be cost-effective using conventional willingness-to-pay thresholds, assuming that those detected through screening have a comparable stroke risk profile as those detected through routine practice. Raising the start age of screening or increasing the screening interval may improve the cost-effectiveness of a prospective screening program.”19
The study “Worldwide epidemiology of atrial fibrillation” concluded, “There have been progressive increases in the worldwide prevalence and incidence of AF with significant effects on associated morbidity and mortality, findings that have implications for public health policy and health care costs.”20
What’s more, the SCREEN-AF study that was published earlier this year — which examined screening for AF in older populations — found a tenfold increase in AF detection for those who wore a continuous ECG monitor versus the control group who received standard care.21 JAMA Cardiology editors Roopinder K. Sandhu, MD, MPH and Christine Albert, MD, MPH weighed in on this study in the February issue, stating, “This trial also demonstrated that AF screening within an existing health care infrastructure and well-defined care pathway can lead to changes in patient management.” They concluded, “The needle [for AF screening] will only move forward once the results from studies evaluating clinical end points and cost-effectiveness are completed and more data are available regarding potential harms of screening. Ultimately, implementation will require a detailed assessment of health care systems’ capacity to integrate AF screening into routine care.”22
In the meantime, Steinhubl et al. confirm that “very effective therapies can prevent stroke and systemic embolization in patients with AF.”23 Thus, with significant potential to save lives and reduce healthcare costs, the case for AF screening as a vital sign is becoming clear.