Late-Breaking Highlights: “To Screen Or Not To Screen And Then What? Studies of Detection and Treatment of AF”

This was an exciting session at AHA 2020 which focused on clinical trials of screening, monitoring, and early intervention in Atrial Fibrillation (AF). Screening of AF is a controversial topic and for individuals >65 years, current AHA guidelines give a Grade 2a recommendation for screening whereas USPSTF guidelines suggest that there is insufficient evidence for screening. In this article, I will be discussing studies that addressed AF screening and their implications on clinical practice with Dr. Stavros Stavrakis who is an electrophysiologist and Associate Professor at the University of Oklahoma Health Sciences Center, Oklahoma City.

Question: What are the important goals when we think about screening for AF?

Dr. Stavrakis: The important goals for screening in AF are to establish a diagnosis of new AF in patients at high risk of stroke so they can be anticoagulated, ultimately reducing the risk of stroke.

There were 3 important trials that addressed AF screening in different patient populations.


  • In patients who have undergone cardiac surgery and have a higher risk of stroke but no history of pre-operative or pre-discharge AF, what is the risk of developing AF/Aflutter in the sub-acute post discharge period?
  • 336 post-cardiac surgery patients (median CHADS2Vasc Score 4) but with little or no AF in the post-operative period (<24 hours of AF but no intent to anticoagulate at discharge) were randomized to continuous cardiac rhythm monitoring vs usual care during the sub-acute post discharge period.
  • In the enhanced cardiac rhythm monitoring group 19.6% participants developed AF/Aflutter as compared with 1.7% in the usual care group with an absolute rate difference 17.9% (p<0.001, NNS=6).

Question: What are the implications of this trial on clinical practice?

Dr. Stavrakis: Risk of POAF, although peaking at 48-72hours post-op, is not confined to the index hospitalization, continuous monitoring for POAF can identify AF in a significant proportion of patients (20%) that may need treatment with anticoagulation. Whether anticoagulation improves outcomes in these patients, remains to be determined.


  • Among older adults (age>65) presenting to primary care visits, does point of care rhythm assessment with a single lead ECG result in increased diagnosis of AF?
  • 30,722 patients were randomized to screening vs control.
  • Screening did not significantly affect AF diagnosis in the overall study sample (1.74% vs 1.60%, p=0.33)
  • Increased likelihood of AF diagnosis at primary care encounter (p<0.02)
  • Effectiveness of screening varied by age with effective screening in age>85 (risk difference 1.88%, NNS=53)
  • Overall no difference in the initiation of anticoagulation

Question: What are the implications of this trial on clinical practice?

Dr. Stavrakis: There are 2 important implications from this trial.

  1. Screening everyone age>65 for AF at a single time point is not an efficient way to detect AF, especially if the usual care is very good in detecting AF by pulse palpation or BP device.Screening at age>85 may be more effective than usual care to identify silent AF, but it is uncertain if it changes management or outcomes


  • Can screening for AF by wearing an ECG patch improve clinical outcomes at 3-years?
  • 1718 actively monitored participants vs 3371 matched observational controls with analysis of 3-year clinical outcomes.
  • Mean duration of follow-up was 29 months
  • 11.4% of actively monitored patients developed AF vs 7.3% of matched controls
  • No difference in anticoagulation prescription between both arms (45.2% vs 44%, p=0.84)
  • 3-year Primary combined end point (death, stroke, systemic embolism or MI) for entire cohort was 4.5 vs 5.5 per 100 person-year (HR 0.79, p<0.01) and for diagnosed AF patients it was 8.4 vs 13.8 per 100 person-year (HR 0.53, p<0.01).

Question: What are the implications of this trial on clinical practice?

Dr. Stavrakis: Clinical outcomes can be improved with AF screening provided these patients are followed up for extended periods of time. However, this was not a randomized trial and unknown confounders may have influenced the outcome.

Question: What are 3 important unanswered questions pertinent to screening of AF?

  1. What is the impact of AF screening on clinical outcomes? Large studies, adequately powered to detect clinical outcomes, are underway (SAFER, HEARTLINE, GUARD-AF).
  2. What is the optimal screening intensity that identifies AF which would benefit from anticoagulation?
  3. What is the minimum AF burden that, if identified with screening, would benefit from anticoagulation?

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