#289 Afib Triple Distilled

August 11, 2021 | By Matthew Watto, MD

Enjoy this rapid clinical overview of afib (atrial fibrillation) based on Curbsiders episode #159 with Cardiologist Dr. James Furgerson; Plus, updates on ablation and left atrial appendage occlusion! 

This episode is not available for CME, but episode #159 on Atrial Fibrillation is available for CME credit through the ACP!

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Credits

• Written, Produced, and Hosted by: Matthew Watto MD, FACP; Paul Williams MD, FACP; Beth Garbitelli
• Editor: Matthew Watto MD (written materials); Clair Morgan of nodderly.com

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Show Segments

• Intro, disclaimer, guest bio
• Afib prevention
• Workup for afib
• Treatment of afib
• Updates on ablation, Left atrial appendage occlusion
• Outro

Episode #159 Atrial Fibrillation

Featuring Dr. James Furgerson, production and infographic by Cyrus Askin

Afib Prevention

The primary care doctor is relevant to preventing and controlling atrial fibrillation as there are many modifiable risk factors, including obesity, hypertension, OSA, and alcohol use. 

The benefit of weight loss/exercise to reduce burden of afib (Chung et al, 2020)

Dr. Furgerson mentioned that patients with afib should be encouraged to avoid even moderate alcohol intake, BUT that caffeine intake is probably safe (Kim, 2021)!

Afib Workup

• Dr. Furgerson checks a CBC, CMP, TSH, echocardiogram and chest xray
• Evaluate risk of OSA and have low threshold to send sleep study
• Cardiac monitoring may be considered
• Dr. Furgerson notes that ischemia is not a common association

Duration, Setting of afib

• Incidentally discovered afib is common with wearable and implantable devices, but we don’t yet know what duration matters.
• Dr. Furgerson considers minutes to hours of sustained afib as significant (expert opinion).
• The presence of afib predicts future afib. Thus, Dr. Furgerson always considers afib as significant even if provoked by an event like critical illness (expert opinion). 
• Consider risk profile (e.g. CHADS2VASC score) to determine stroke risk for any patient with an episode of afib (2014 ACC/AHA/HRS g/l)
• Thyrotoxicosis and post-op after CABG are the two situations where afib can probably be dismissed as transient. Dr. Furgerson mentioned cardiac monitoring about 1 month after CABG to detect any persistent afib (expert opinion)

Rate Vs Rhythm Control

• Spontaneous conversion is common for patients presenting with new afib. 
• Rhythm control becomes more challenging as the duration of afib increases.
• Antiarrhythmics have a narrow therapeutic index, many drug-drug interactions, and require frequent monitoring.
• The AFFIRM trial (Wyse, NEJM 2002) did not find a mortality benefit for rhythm control vs rate control, but patients with rhythm control required more frequent hospitalizations.
• Dr. Furgerson chooses rhythm control for patients who cannot achieve adequate rate control, those with preexcitation (WPW), young/active athletes, or for those who poorly tolerate afib (palpitations, SOB, dizziness, heart failure)
• Radiofrequency ablation did not decrease MACE in a large RCT of all-comers with afib (CABANA), but the smaller CASTLE-AF trial in patients with afib and HFrEF found decreased MACE.
• Bottom line: There are a lot of nuances. Refer to Cardiology-EP if you think a patient may benefit.

Treatment of Afib

• Anticoagulation is recommended for CHADS2VASC of ≥2 in men or ≥3 in women (IA –2019 ACC/AHA/HRS g/l). Consider treatment if score of 1 in men or 2 in women.
• DOACs are preferred to VKA (IA) unless mechanical valve is present, or if moderate to severe mitral stenosis 2019 ACC/AHA/HRS g/l
• Rate of <80 is preferred (IIa), but rate of <110 (IIb) at rest is acceptable (RACE II) to prevent MACE (2014 ACC/AHA/HRS g/l). Dr. Furgerson notes that most cardiologists shoot for <80, but settle for leniency if rate control proves difficult.

Updates since this one aired:

LAAO (left atrial appendage occlusion) closure in patients with afib undergoing cardiac surgery for another indication led to a decrease in stroke or systemic embolism in an RCT with 3.8 years follow up. Editorialist notes this will likely become a standard of care. (Whitlock, NEJM 2021)

CABANA was a large, negative trial of ablation for all-comers with afib. However, a new prespecified follow up study of afib ablation for patients with heart failure (most had HFpEF) was published, suggesting lower mortality and improved quality of life (Packer, Circulation 2021)

Rhythm control is not dead! The EAST-AFNET4 trial of rhythm control (antiarrhythmics or with ablation) vs rate control for patients with recently diagnosed afib (<1 year) found a decrease in the primary composite CV outcome (cardiovascular-related death, stroke, hospitalization for heart failure [HF], or acute coronary syndrome). Stay tuned! —Fleischmann, JWatch 2021. 

Goal

Listeners will the key concepts and clinical pearls from past Curbsiders episodes on afib

Learning objectives

After listening to this episode listeners will…  

1. Counsel patients about afib prevention
2. Develop a framework to evaluate and treat afib

Disclosures

Dr Furgerson reports no relevant financial disclosures. The Curbsiders report no relevant financial disclosures. 

Citation

Watto MF, Williams PN, Garbitelli B. “#289 Afib Triple Distilled”. The Curbsiders Internal Medicine Podcast. http://thecurbsiders.com/episode-list Final publishing date August 11, 2021.