Research Priorities in Atrial Fibrillation Screening: A Report From a National Heart, Lung, and Blood Institute Virtual Workshop

Abstract

Clinically recognized atrial fibrillation (AF) is associated with higher risk of complications, including ischemic stroke, cognitive decline, heart failure, myocardial infarction, and death. It is increasingly recognized that AF frequently is undetected until complications such as stroke or heart failure occur. Hence, the public and clinicians have an intense interest in detecting AF earlier. However, the most appropriate strategies to detect undiagnosed AF (sometimes referred to as subclinical AF) and the prognostic and therapeutic implications of AF detected by screening are uncertain. Our report summarizes the National Heart, Lung, and Blood Institute's virtual workshop focused on identifying key research priorities related to AF screening. Global experts reviewed major knowledge gaps and identified critical research priorities in the following areas: (1) role of opportunistic screening; (2) AF as a risk factor, risk marker, or both; (3) relationship between AF burden detected with long-term monitoring and outcomes/treatments; (4) designs of potential randomized trials of systematic AF screening with clinically relevant outcomes; and (5) role of AF screening after ischemic stroke. Our report aims to inform and catalyze AF screening research that will advance innovative, resource-efficient, and clinically relevant studies in diverse populations to improve the diagnosis, management, and prognosis of patients with undiagnosed AF.

Keywords: atrial fibrillation; diagnostic screening programs; prevention and control; research; stroke.

Figure 1.

Comparison of opportunistic single timepoint screening with systematic and consumer-led screening. Illustrates trade-offs between screening intensity/AF yield and stroke risk of screen-detected AF, along the screening intensity continuum.

Figure 2.

Opportunistic single timepoint screening for AF. Questions remain regarding screening test accuracy by methodology, how often to screen, harms from screening, and if treating screen-detected AF has the same benefits as clinically-detected AF.

Figure 3.

Both AF risk factors (left, some examples given) and health data - including sophisticated imaging and biomarker data - may distinguish individuals at low (green), intermediate (yellow), and high (red) risk, both in terms of incident (or recurrent) AF as well as major adverse cardiovascular and cerebrovascular events and conditions (MACCE). Both retrospective and prospective studies should compare risk prediction by standard models and artificial intelligence, taking the elements within upper main ellipse into account, including response to risk management, incident AF, and MACCE. The strategy for prioritization of research would focus most efficiently on people with high risk of AF and MACCE (upper potential screen threshold for research). BMI: body mass index; BNP: brain natriuretic peptide; DM: diabetes mellitus; EHR: electronic health record; HF: heart failure; HTN: hypertension; VHD: valvular heart disease

Figure 4.

Knowledge gaps and research opportunities to be addressed in randomized trials of screening for AF.

Figure 5.

Questions to address in screening for AF in individuals who experience a new ischemic stroke in the absence of previously recognized AF. It will be important to identify when, how, and who to monitor post-stroke.