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AF Diagnosis and Management

CE / CME

Atrial Fibrillation Case Considerations: Diagnosis and Screening

Physician Assistants/Physician Associates: 0.50 AAPA Category 1 CME credit

Nurses: 0.50 Nursing contact hour

Physicians: maximum of 0.50 AMA PRA Category 1 Credit™

Released: December 29, 2023

Expiration: December 28, 2024

Camille Dyer
Camille Dyer, MS, PA-C, AACC, DFAAPA
CME/CE Information

Activity

Progress
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Course Completed

Discussion
Atrial fibrillation (AF) is the most common cardiac arrhythmia observed in clinical practice and is the leading risk factor for stroke.1-4 AF prevalence increases with age, from <0.1% in persons younger than 55 years of age to 9% to 29% in persons 80 years of age and older.4,5 In the United States, it is expected that the prevalence of AF will increase to more than 12 million cases in 2030.3 However, in the United States, 10% to 27% of all patients with AF remain undiagnosed, as it frequently has minimal or no symptoms.6,7 In this case, Mrs. Sims has many risk factors for AF, including her age, putting her at higher risk for the development of AF.

One of the primary consequences of AF is increased risk for stroke and other heart-related conditions. AF confers a 5-fold increased risk of stroke and accounts for nearly 25% of strokes occurring after 80 years of age.8,9 It also leads to more severe strokes than other causes, with a 1-year combined rate of mortality and disability of 71%.10,11 Similar to how AF prevalence increases with age, the risk of stroke in patients with AF increases with age and the presence of comorbidities such as hypertension, heart failure, obesity, chronic kidney disease, diabetes, and prior transient ischemic attack or stroke.12 Mrs. Sims has several risk factors that increase her chance of developing AF, including type 2 diabetes, COPD, obesity, hyperlipidemia, hypertension, and heart failure. These combined with her age create a compelling picture for her to at a minimum be screened for AF.

Secondary analysis of the VITAL-AF trial, encompassing more than 17,000 patients in the primary care setting without a prior diagnosis of AF, found that 28.5% of patients aged 85 years and older had AF.5 Because of the asymptomatic, paroxysmal nature AF, 10% to 27% of patients with AF remain undiagnosed.6,7,13 Patients with undiagnosed AF are more likely to be older, with higher CHA2DS2-VASc scores compared with patients with diagnosed AF. A retrospective analysis demonstrated that 93% of patients with undiagnosed AF had a CHA2DS2-VASc of ≥2 and were eligible for oral anticoagulant therapy.13 If Mrs. Sims were to be diagnosed with AF, her CHA2DS2-VASc score would be 5 (2 points for age, 1 point for diabetes, 1 point for hypertension, and 1 point for age), making her adjusted annual risk of stroke 6.7%. It is estimated that in 20% of patients who have a stroke associated with AF, the index stroke is the first sign of AF, and up to 30% of unexplained strokes may be due to undiagnosed AF.14,15

Although AF is known to be “clinically silent,” improved screening can help identify at-risk patients who would benefit from treatment with anticoagulants, which can significantly decrease the risk of stroke. Multiple guidelines offer recommendations on appropriate screening and diagnosis of AF, and related guidelines provide recommendations on stroke prevention in patients with AF.16-20 Screening Mrs. Sims for AF and initiating anticoagulation if she is found to have AF will reduce her risk of experiencing an index stroke. New technology also offers alternative methods to detect irregular heart rhythms. For example, with the advent of small, noninvasive devices such as the portable ECG and smartphone apps, healthcare professionals can easily assess heart rhythm when screening patients with AF.21 Although this may help individuals with the financial ability to obtain these resources, it is imperative that we ensure those without access are also adequately screened. Screening methods such as pulse palpation, either in clinic or at home, can provide an easy and affordable screening method to individuals who may otherwise go without.

Numerous studies have shed light on risk factors for AF that can be used to identify candidates for routine screening. The Swedish STROKESTOP study identified that patients aged 75-76 years with known vascular disease were more likely to be diagnosed with AF. Consistent with earlier data from the Framingham Heart Study cohort, the strongest predictors of AF were congestive heart failure or diabetes and history of previous transient ischemic attack or stroke.22,23 Mrs. Sims meets 2 of these 3 criteria. A more recent study developed an AF risk prediction score using data from the UK Biobank cohort, validated with data from the Framingham Heart Study cohort.24 Using the variables of hypertension, age, raised BMI, male sex, sleep apnea, smoking, and alcohol use (HARMS2-AF), this score was able to identify individuals at risk for AF and may be a useful tool to facilitate screening of AF in the primary care setting.

Based on the international AF-SCREEN collaboration, the American Heart Association has concluded that age-based screening using pulse palpation or single-timepoint handheld devices is an efficient method for diagnosing asymptomatic AF.16 However, a limitation of single-timepoint screening is the potential to miss paroxysmal AF, which also is associated with increased stroke risk.22,25 Thus, community or clinic-based single-timepoint screening is recommended for people aged 65 years and older, but more intensive, twice-daily, intermittent screening for 2 weeks may be appropriate for patients of any age or patients aged 75 years and older who are at high risk for stroke. In addition, ECG screening for AF is recommended for patients after an ischemic stroke or for those who have experienced an embolic stroke of undetermined source.  

Screening asymptomatic patients for AF has been proposed as a way of reducing the burden of stroke by detecting those who could benefit from anticoagulants prior to the onset of symptomatic arrhythmia.26 However, current evidence is insufficient to recommend for or against universal screening for AF to improve health outcomes.27 In addition, some screening methods may detect subclinical, short-duration, or low-burden AF, for which there is uncertainty regarding the merits of treatment.15,28,29 Thus, most guidelines recommend a risk-based approach to screening in asymptomatic patients, taking patient age as a starting point. The European Society of Cardiology guidelines recommend opportunistic pulse taking and ECG screening for AF in patients aged 65 years and older and systematic ECG monitoring in patients aged 75 years and older who are at high risk of stroke.17 Although Mrs. Sims falls into the latter category, she is unlikely to be able to afford serial ECG monitoring. Systematic screening with an ECG rhythm strip is more expensive but is an alternative for the detection of paroxysmal AF and secondary prevention after a transient ischemic attack or stroke, or for older patients and those at very high risk for stroke.17 As a result, it is reasonable to start with pulse palpation for Mrs. Sims to ensure the most cost-effective care for her. Pulse palpation is a readily accessible method to check pulse for screening in primary care settings and has been shown to be an effective screening strategy.30 It also can be easily performed by patients, so if needed, they can be appropriately trained to detect pulse irregularity. Education to emphasize the use of simple methods such as pulse palpitation or cardiac auscultation to increase detection of AF could significantly improve diagnosis and management.16