July 20, 2021  •  15 min read

The case for atrial fibrillation (AF) as the next vital sign.

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.

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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.

How screening for silent AF is (or is not) conducted today.

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:

  • A reduction in stroke and other thromboembolic events, and decrease in the related health burden
  • High reliability (near 100%) and safety of ECG monitoring
  • Significant positive impact of treatment once diagnosed,8 including fewer emergency room visits and a decrease in hospitalizations9

Improving the status quo.

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

The shortcomings of consumer wearables alone.

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 percent 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 case for AF as a vital sign.

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.

  1. Atrial fibrillation. Centers for Disease Control and Prevention. Updated September 8, 2020. Accessed on July 2, 2021. https://www.cdc.gov/heartdisease/atrial_fibrillation.htm
  2. Colilla S, Crow A, Petkun W, Singer DE, Simon T, Liu X. Estimates of current and future incidence and prevalence of atrial fibrillation in the U.S. adult populationAm J Cardiol. 2013;112(8):1142-1147. doi:10.1016/j.amjcard.2013.05.063
  3. Complications atrial fibrillation. NHS. Updated May 17, 2021. Accessed on July 2, 2021. https://www.nhs.uk/conditions/atrial-fibrillation/complications/
  4. Khurshid S, Healey JS, McIntyre WF, Lubitz SA. Population-based screening for atrial fibrillationCirc Res. 2020;127(1):143-154. doi:10.1161/CIRCRESAHA.120.316341
  5. Freedman, et al. Silent atrial fibrillation. ESC CardioMed. Oxford, UK: Oxford University Press. Oxford Medicine Online. Updated July 2018. Accessed on July 2, 2021. https://oxfordmedicine.com/view/10.1093/med/9780198784906.001.0001/med-9780198784906-chapter-500
  6. Hindricks G, Potpara T, Dagres N, et al. 2020 ESC Guidelines for the diagnosis and management of atrial fibrillation developed in collaboration with the European Association for Cardio-Thoracic Surgery (EACTS): The Task Force for the diagnosis and management of atrial fibrillation of the European Society of Cardiology (ESC) Developed with the special contribution of the European Heart Rhythm Association (EHRA) of the ESC [published correction appears in Eur Heart J. 2021 Feb 1;42(5):507] [published correction appears in Eur Heart J. 2021 Feb 1;42(5):546-547] [published correction appears in Eur Heart J. 2021 Feb 1;42(5):541-543]. Eur Heart J. 2021;42(5):373-498. doi:10.1093/eurheartj/ehaa612
  7. Steinhubl SR, Waalen J, Edwards AM, et al. Effect of a home-based wearable continuous ECG monitoring patch on detection of undiagnosed atrial fibrillation: the mSToPS randomized clinical trial. JAMA. 2018;320(2):146-155. doi:10.1001/jama.2018.8102
  8. Steinhubl SR, Mehta RR, Ebner GS, et al. Rationale and design of a home-based trial using wearable sensors to detect asymptomatic atrial fibrillation in a targeted population: the mHealth Screening To Prevent Strokes (mSToPS) trialAm Heart J. 2016;175:77-85. doi:10.1016/j.ahj.2016.02.011
  9. Waalen J, Edwards AM, Sanyal A, et al. Healthcare resource utilization following ECG sensor patch screening for atrial fibrillationHeart Rhythm O2. 2020;1(5):351-358. Published 2020 Oct 8. doi:10.1016/j.hroo.2020.09.005
  10. Lip. CHA₂DS₂-VASc score for atrial fibrillation stroke risk. MD+CALC. Accessed July 2, 2021. https://www.mdcalc.com/cha2ds2-vasc-score-atrial-fibrillation-stroke-risk
  11. Siddiqi TJ, Usman MS, Shahid I, et al. Utility of the CHA2DS2-VASc score for predicting ischaemic stroke in patients with or without atrial fibrillation: a systematic review and meta-analysis [published online ahead of print, 2021 Mar 9]. Eur J Prev Cardiol. 2021;zwab018. doi:10.1093/eurjpc/zwab018
  12. Hindricks G, Potpara T, Dagres N, et al. 2020 ESC Guidelines for the diagnosis and management of atrial fibrillation developed in collaboration with the European Association for Cardio-Thoracic Surgery (EACTS): The Task Force for the diagnosis and management of atrial fibrillation of the European Society of Cardiology (ESC) Developed with the special contribution of the European Heart Rhythm Association (EHRA) of the ESC [published correction appears in Eur Heart J. 2021 Feb 1;42(5):507] [published correction appears in Eur Heart J. 2021 Feb 1;42(5):546-547] [published correction appears in Eur Heart J. 2021 Feb 1;42(5):541-543]. Eur Heart J. 2021;42(5):373-498. doi:10.1093/eurheartj/ehaa612
  13. Steinhubl SR, Mehta RR, Ebner GS, et al. Rationale and design of a home-based trial using wearable sensors to detect asymptomatic atrial fibrillation in a targeted population: the mHealth Screening To Prevent Strokes (mSToPS) trialAm Heart J. 2016;175:77-85. doi:10.1016/j.ahj.2016.02.011
  14. Somsen GA. The role of ECG screening in primary care; a call for collaboration between general practitioner and cardiologist. Neth Heart J. 2020;28(4):190-191. doi:10.1007/s12471-020-01410-4
  15. Smaller companies fuel growth in worldwide wearables market in 1Q21, says IDC. IDC. Updated May 27, 2021. Accessed July 2, 2021. https://www.idc.com/getdoc.jsp?containerId=prUS47794121
  16. Isakadze N, Martin SS. How useful is the smartwatch ECG? Trends Cardiovasc Med. 2020;30(7):442-448. doi:10.1016/j.tcm.2019.10.010
  17. Wolf PA, Abbott RD, Kannel WB. Atrial fibrillation as an independent risk factor for stroke: the Framingham Study. Stroke. 1991;22(8):983-988. doi:10.1161/01.str.22.8.983
  18. Cost analysis concludes that the direct cost of stroke, at US$35 billion annually, represents only the tip of the iceberg. Neuro News. Updated April 5, 2019. Accessed July 2, 2021. https://neuronewsinternational.com/cost-analysis-concludes-that-the-direct-cost-of-stroke-at-us35-billion-annually-represents-only-the-tip-of-the-iceberg/
  19. Moran PS, Teljeur C, Harrington P, et al. Cost-effectiveness of a national opportunistic screening program for atrial fibrillation in IrelandValue Health. 2016;19(8):985-995. doi:10.1016/j.jval.2016.07.007
  20. Chugh SS, Havmoeller R, Narayanan K, et al. Worldwide epidemiology of atrial fibrillation: a Global Burden of Disease 2010 study. Circulation. 2014;129(8):837-847. doi:10.1161/CIRCULATIONAHA.113.005119
  21. Gladstone DJ, Wachter R, Schmalstieg-Bahr K, et al. Screening for atrial fibrillation in the older population: a randomized clinical trial. JAMA Cardiol. 2021;6(5):558–567. doi:10.1001/jamacardio.2021.0038
  22. Sandhu RK, Albert C. Screening the older population for atrial fibrillation—have we moved the needle forward? JAMA Cardiol. 2021;6(5):495–496. doi:10.1001/jamacardio.2021.0052
  23. Steinhubl SR, Mehta RR, Ebner GS, et al. Rationale and design of a home-based trial using wearable sensors to detect asymptomatic atrial fibrillation in a targeted population: the mHealth Screening To Prevent Strokes (mSToPS) trialAm Heart J. 2016;175:77-85. doi:10.1016/j.ahj.2016.02.011

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