#363 Afib: Rhythm Control, Catheter Ablation, Afib in the hospital, and Left Atrial Appendage Closure

October 31, 2022 | By Matthew Watto, MD

Video

Optimize and update your approach to atrial fibrillation (afib) as we discuss early rhythm control, antiarrhythmic drugs, TTE/cardioversion, afib ablation, new onset afib in the hospitalized patient, and left atrial appendage closure. Plus, we try to answer, Does afib burden matter? Our guest is cardiologist-electrophysiologist, Hugh Calkins MD, @hughcalkinsMD, Professor of Cardiology at Johns Hopkins, @hopkinsheart. 

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Credits

• Written and Produced by: Matthew Watto MD, FACP
• Show Notes: Matthew Watto MD, FACP
• Cover art and Infographic by:
• Hosts: Matthew Watto MD, FACP; Paul Williams MD, FACP   
• Reviewer: Emi Okamoto MD
• Showrunners: Matthew Watto MD, FACP; Paul Williams MD, FACP   
• Technical Production: PodPaste
• Guest: Hugh Calkins MD

Sponsor: Grammarly

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CME Partner: VCU Health CE

Show Segments

• Intro, disclaimer, guest bio
• Guest one-liner
• Case from Kashlak; Definitions
• An approach to new-onset afib in the office
• Rhythm control
• Lifestyle modification is a pillar of afib treatment
• Indications for hospitalization in afib
• More on rhythm control and when to pursue afib ablation
• Rhythm control in heart failure
• New onset afib in the hospitalized patient
• Does afib burden matter?
• Left atrial appendage closure 
• Watto and Paul recap what we’ve learned
• Outro

Afib Pearls

1. Lifestyle modification is the fourth pillar in afib management. Treat diabetes, hypertension, sleep apnea, and obesity. Promote physical activity. Encourage smoking cessation and limit or stop alcohol use. (Chung, 2020)
2. New onset afib: Start patients on rate control and anticoagulation in case they need cardioversion. Perform home monitoring of heart rhythm and schedule close follow-up. 
3. Afib is an outpatient disease absent syncope, heart failure, chest pain, or complex patient factors like bleeding or poor social support. 
4. Per Dr. Calkins’ expert opinion, every patient deserves a trial of sinus rhythm, especially early after diagnosis. Often, this will be electric cardioversion +/- an antiarrhythmic drug.
5. Catheter ablation may be considered in experienced centers, particularly for symptomatic paroxysmal afib (Per 2014 guidelines, section 6.3) or those who did not achieve rhythm control with antiarrhythmic drugs. 
6. New onset afib in the hospitalized patient is likely to recur and confers an increased risk of thromboembolism. Treat these episodes as true afib. 
7. Multiple options exist for left atrial appendage closure. Patients with bleeding contraindications or lifestyles incompatible with long-term anticoagulation are candidates. 
   
   

Lifestyle and risk factor modification

Primary care clinicians have a major role in the treatment and prevention of afib. 

• Lifestyle modification is the fourth pillar in afib management along with rate control, rhythm control, and anticoagulation. 
• Treat diabetes, hypertension, sleep apnea, and obesity. Promote physical activity. Encourage smoking cessation and limit or stop alcohol use. (Chung, 2020)
• Afib has been linked to heart failure (Carlisle, 2019), dementia (Bunch, 2020 ), and a shorter life. (Lee, 2018)

The patient in clinic with new afib

• Symptoms can range from asymptomatic to mild to severe. 
• We should view afib as an outpatient disease (expert opinion). 
• Order an echo, TFTs, and some sort of cardiac monitoring to determine if continuous or intermittent afib.
• Monitor HR either with wearables or a two-week event monitor to determine if paroxysmal or persistent afib (expert opinion). 
• Put the patient on an anticoagulant in case they will require cardioversion (expert opinion).
• Start a beta blocker for rate control. Double the dose as needed for control. Dr. Calkins targets 80 bpm at rest.  
• Follow up with the patient in a week or so. If still in afib, then plan for cardioversion after 3 weeks of anticoagulation. 

Who needs an inpatient evaluation?

Not all patients with new onset afib need hospitalization. Dr. Calkins cited the following scenarios as potential indications for hospital management: 

• Syncope or severe pre-syncope
• Heart failure
• Chest pain 
• Sometimes patients with comorbidities like bleeding that would complicate treatment

Reasons to try rhythm control 

“Many patients say, ‘I feel fine.’ Then, they get back to sinus rhythm. They say, ‘Wow…I didn’t know what fine really was. I thought I was getting old.’” -Dr. Calkins

Note: on our prior episode #159 with Dr. James Furgerson we discussed multiple scenarios where rhythm control is warranted including patients who cannot achieve adequate rate control, those with pre-excitation (WPW), young/active athletes, or for those who poorly tolerate afib (palpitations, shortness of breath, dizziness, heart failure)

• The longer a patient is in afib the harder it is to get them out of afib. 
• Dr. Calkins notes that “getting someone back to sinus rhythm with an antiarrhythmic drug (AAD)  is extraordinarily unlikely”. Thus, electrical cardioversion is usually needed followed by an AAD to maintain sinus rhythm. 

Updates on Rhythm Control

• The AFFIRM trial (Wyse, 2002) did not find a mortality benefit for rhythm control vs rate control, but patients with rhythm control required more frequent hospitalizations. Several recent trials have challenged this notion (see below).
• The 2020 EAST-AFNET4 trial of rhythm control (mostly using antiarrhythmics, but some 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). 
• Catheter 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.
• Additionally, a new pre-specified follow-up study of CABANA looked at afib ablation for patients with heart failure (most had HFpEF) and found lower mortality and improved quality of life (Packer, 2021)
• Dr. Calkins notes that the patients in CASTLE-AF and Packer et al were a highly selected group so results do not apply to all-comers with heart failure. 
• The role of catheter ablation is less certain in folks with HFpEF per Dr. Calkins. He speculates this may reflect the varying phenotypes of HFpEF. He notes it’s still not clear how to best select patients for treatment. 
• Catheter ablation, compared to medical therapy with mostly antiarrhythmics, did not decrease MACE in a large RCT of all-comers with afib in the CABANA trial (2020). However, a new pre-specified follow-up study of CABANA looked at afib ablation for patients with heart failure (most had HFpEF) and found lower mortality and improved quality of life (Packer, 2021).
• The smaller CASTLE-AF trial (2018) in patients with symptomatic or persistent afib and HFrEF found decreased MACE with catheter ablation, as compared to continued medical therapy.
  • Dr. Calkins notes that the patients in CASTLE-AF and Packer et al were a highly selected group so results do not apply to all-comers with heart failure. 
• Catheter ablation for initial rhythm control in non-HF? Three RCT studies in the past year compared catheter ablation vs anti-arrhythmic drugs in treatment-naive individuals with paroxysmal afib (Angrade, 2021; Kuniss, 2021; Wazni, 2021; Review of Cryoablation by Angrade 2021).
  • It should be noted that Medtronic makes cryoablation devices and helped support these studies. 

General Principles of Rhythm control

• Cardioversion (electrical or pharmacologic) for afib present ≥48 hours or for unknown time requires three weeks of anticoagulation prior, then four more weeks afterward. If a TEE is done to “clear the atrial appendage” before cardioversion or afib has been present ≤48 hours, then start anticoagulation and most should continue for at least 4 weeks afterward (2019 AHA/ACC/HRS guidelines)
• Electric cardioversion is recommended for afib if pursuing a rhythm control strategy (2014 AHA/ACC/HRS Guidelines)
  • Short or unknown duration afib: Trial cardioversion without an antiarrhythmic drug (expert opinion)
  • Long-term afib: Start an antiarrhythmic drug three days before electrical cardioversion and continue it afterward (expert opinion).
• Recurrent afib despite cardioversion and anti-arrhythmic drug: Consider proceeding to catheter ablation (2014 AHA/ACC/HRS Guidelines).
• Catheter ablation as initial rhythm control? This strategy was noted as a consideration  for experienced centers in 2014 AHA/ACC/HRS Guideline, though Dr. Calkins notes challenges with getting timely catheter ablation
  • Catheter ablation and HFrEF: The 2019 AHA/ACC/HRS Guidelines include a moderate (IIb) recommendation that catheter ablation may be reasonable in select cases with HFrEF.
• Consider catheter ablation if recurrent afib despite an attempt at rhythm control with an antiarrhythmic drug (2014 AHA/ACC/HRS Guidelines).
  • Dr. Calkins tries to have patients in sinus rhythm and on full anticoagulation at the time of an afib ablation because a) it helps shrink the atrium, “reverse remodeling” and b) they may have a lower risk of stroke at the time of ablation (expert opinion).
  • Note: Not all centers perform ablations on antiarrhythmic drugs because some look for non-pulmonary vein triggers (Marchlinski, 2019 ). 

Afib and heart failure: A Chicken and Egg Problem

• Afib-induced heart failure with ventricular dysfunction (rate-related cardiomyopathy) can be a reversible condition with timely diagnosis and treatment (Qin, 2019).
• Check an echo after a new afib diagnosis to look for rate-related cardiomyopathy.
• Get these patients back into sinus rhythm and see if the heart failure improves to figure out which came first (afib or heart failure).
• Dr. Calkins promptly schedules TEE cardioversion and then starts amiodarone to maintain sinus rhythm.
• In the long-term many of these patients may benefit from catheter ablation, but there is often a wait list of several months and Dr. Calkins likes to have patients in sinus rhythm when performing an ablation to increase the success rate (expert opinion). 
• Dr. Calkins cautions that if starting an antiarrhythmic drug without a TEE, then patients must be on anticoagulation at least 3 weeks beforehand because spontaneous conversion (from the AAD) could lead to stroke.

Catheter ablation vs Anti-arrhythmic drugs as initial therapy

Three RCT studies in the past year compared initial rhythm control with catheter ablation vs anti-arrhythmic drugs in treatment-naive individuals with paroxysmal afib (Angrade, 2021; Kuniss, 2021; Wazni, 2021; Review of Cryoablation by Angrade 2021). It should be noted that Medtronic makes cryoablation devices and helped support these studies. 

Paroxysmal afib in the hospital

Many of us struggle with how to handle paroxysmal afib that occurs when patients are sick in the hospital or post-operatively. The old thinking was to give folks a “free pass” for these afib episodes, but now we know these patients are at risk for recurrent afib and embolic events (Iontis Ann Int Med 2022; Ramanathan, 2021; Qian, 2021).

• Dr. Calkins recommends treating new afib in the hospital as true afib because they are likely to have it again moving forward. This means starting patients on rate control and at least temporary anticoagulation –expert opinion.
• While sick in the ICU, Dr. Calkins sometimes places patient on reversible anticoagulation to decrease stroke risk in case they require an inpatient cardioversion (expert opinion).
• Subsequent cardiac monitoring can help determine afib burden, but recurrence rates are high and risk remains elevated.

Afib burden and Pill-in-the-pocket Approach

• Afib burden is not part of the CHADSVASc score, but patients with an increased afib burden likely have a different risk then patients with infrequent afib (Yang, 2022; Go, 2018). For example, a patient with permanent afib and CHA2DS2-VASc score of 4 likely has a higher risk than a patient with infrequent paroxysmal afib and a CHA2DS2-VASc score of 4. 
• Pill-in-the-pocket anticoagulation for afib is being studied e.g. monitor for afib with a wearable device and take anticoagulation for 1 month when present (Passman, 2021)

Left atrial appendage (LAA) closure

• Candidates for LAA closure: Dr. Calkins considers it for patients with a contraindication to anticoagulation due to bleeding or patients who desire no anticoagulation due to lifestyle.
• Surgical closure can be accomplished during open surgery, or less invasively with VATS with epicardial clip placement.
• There are two approved left atrial appendage closure devices (LAAD). 
• The FDA recently added DAPT as an alternative to full anticoagulation plus aspirin for the first 45 days following LAAD implantation (https://news.bostonscientific.com/2022-09-06-Boston-Scientific-Receives-FDA-Approval-for-Expanded-Labeling-of-WATCHMAN-FLX-TM-LAAC-Device-for-Dual-Anti-Platelet-Therapy-as-Post-Procedural-Medication-Option accessed 7 Oct 2022)
• The following link features Dr. Calkins and shows multiple options for LAA closure (https://www.hopkinsmedicine.org/health/treatment-tests-and-therapies/left-atrial-appendage-closure-procedures accessed 7 Oct 2022)

Links

Links are provided in the text above. There were no picks of the week on this episode.

Goal

Listeners will update their approach to management of atrial fibrillation

Learning objectives

After listening to this episode listeners will…

1. Develop a standardized approach to outpatients newly diagnosed with atrial fibrillation
2. Decide how to address isolated episodes of “provoked” atrial fibrillation in the hospitalized patient
3. Select afib patients who might benefit from rhythm control with cardioversion +/- antiarrhythmic drugs or catheter ablation. 
4. Become familiar with options for left atrial appendage closure

Disclosures

Dr. Calkins has received consulting fees from Boston Scientific, Medtronic, Atricure, and Biosense. The Curbsiders report no relevant financial disclosures. 

Citation

Watto MF, Calkins H, Williams PN. “#363 Afib: Rhythm Control, Catheter Ablation, Afib in the hospital, and Left Atrial Appendage Closure”. The Curbsiders Internal Medicine Podcast. http://thecurbsiders.com/episode-list Final publishing date October 31, 2021.