TLDR;
This podcast episode of "This Week in Cardiology" covers a range of topics including listener feedback on prophylactic pacing after TAVI, GLP-1 use in heart failure patients with reduced ejection fraction (HFrEF), left atrial posterior wall isolation, peridevice leaks after left atrial appendage occlusion, new findings in postcardiac surgery atrial fibrillation (AF), and imaging before AF ablation. The episode challenges existing guidelines and practices, emphasizing the need for more evidence-based approaches in cardiology.
- Listener feedback highlights the importance of considering paroxysmal AV block when deciding on prophylactic pacing after TAVI.
- GLP-1 agonists may not be beneficial and could potentially be harmful in HFrEF patients due to increased heart rate and arrhythmic events.
- Posterior wall isolation with PFA may not result in durable lesions.
- Overcompression during Watchman device implantation may reduce peridevice leaks.
- Postcardiac surgery AF may have a low burden and resolve quickly, questioning the need for routine anticoagulation.
- The utility of pre-ablation imaging to rule out thrombus is discussed, with a call for larger trials to compare TEE, ICE, and no imaging strategies.
Listener Feedback and Corrections [0:44]
The host addresses listener feedback regarding a study on prophylactic pacing after TAVI in patients with conduction disturbances. The study, a substudy from a Quebec group, examined 80 out of 329 patients who received a permanent pacemaker prophylactically after TAVI. While clinical outcomes at one month were similar between prophylactic and non-prophylactic patients, pacing percentage was significantly lower in the prophylactic group (2% vs. 73%). The host acknowledges that pacing percentage less than 1% does not necessarily indicate the pacer was unnecessary due to the potential for paroxysmal AV block. He thanks listeners for pointing out this nuance. Additionally, the host corrects the pronunciation of "sotatercept" and the "hyperaron" trial.
GLP-1 Use in HFrEF Patients [3:18]
The discussion shifts to the use of GLP-1 agonists in patients with heart failure with reduced ejection fraction (HFrEF). An observational study from a Quebec group in JACC Heart Failure assessed the effects of GLP-1 initiation in HFrEF patients with ICDs, comparing GLP-1 users to non-users. The study found that GLP-1 use was associated with a significant increase in heart rate, a numeric increase in VT/VF events, a significant increase in non-sustained ventricular events and total shocks, and an increase in NT-proBNP, despite improvements in BMI and glycemic control. While there was a trend for reduced AF burden in GLP-1 users, the host initially dismissed the study as biased. However, after a discussion with Andrew Foy, the host reviewed older trials (FIGHT, LIVE) that showed negative or concerning outcomes with GLP-1 use in HFrEF patients, including increased heart failure hospitalizations and serious cardiac events. The host concludes that GLP-1 drugs may not be beneficial and could potentially be harmful in HFrEF patients due to the elevation of heart rate and the fragility of this patient population.
Left Atrial Posterior Wall Isolation [9:07]
The host discusses left atrial posterior wall isolation in the context of AF ablation. With the advent of pulse field ablation (PFA), posterior wall isolation has become safer and easier. However, a case series from the Sutter Health Group in JACC EP raises concerns about the durability of posterior wall isolation with PFA. In four out of five patients who underwent hybrid ablation after PFA posterior wall isolation, epicardial mapping revealed epicardial voltage on the posterior wall, even in a patient who had received 64 PFA lesions. This suggests that PFA lesions, while initially effective in obliterating signals, may not be durable or transmural. The host notes that different PFA systems may yield different results, but the study raises questions about the long-term efficacy of posterior wall isolation with PFA.
Peridevice Leaks After Left Atrial Appendage Occlusion [12:37]
The topic shifts to peridevice leaks after left atrial appendage occlusion with the Watchman device. A small study from Dr. Natali's group in JACC EP investigated the clinical impact of Watchman device overcompression during implantation. The study compared patients who underwent overcompression to those who received normal compression according to the instructions for use. While there were no differences in procedural complications and one-year stroke rates were similar, peridevice leaks were significantly less frequent in the overcompression arm (8.2% vs. 33%). The host highlights that even in experienced centers, using the normal instructions for use resulted in a high rate of peridevice leaks. He questions the rate of peridevice leaks in lower-volume centers and when using CT imaging instead of TEE. The host also reminds listeners that the PROTECT AF and PREVAIL trials failed partly because ischemic strokes were more frequent in the Watchman arm, potentially due to peridevice leaks.
New Findings in Postcardiac Surgery AF [15:15]
The host discusses a German cohort study published in JAMA on atrial fibrillation (AF) after coronary artery bypass surgery (CABG). The study used event recorders to monitor 198 patients without a pre-surgical history of AF. The study found that 95 patients developed new-onset AF within the first year, but the median AF burden was low (0.07%). Most AF occurred within the first week, with the median AF burden dropping significantly after day 8. Only three patients had AF longer than 24 hours, and no patient with new-onset AF developed a stroke during follow-up. The authors concluded that while the incidence of AF after CABG is high, the low AF burden questions the need for routine anticoagulation. The host agrees, noting that current guidelines recommending anticoagulation for 60 days or longer may be too aggressive, especially in light of the NOAH and ARTESIA trials. He cautions against using enoxaparin or heparin for AF without evidence of benefit.
Imaging Before AF Ablation [21:05]
The final topic is the use of transesophageal echo (TEE) or intracardiac echo (ICE) to rule out thrombus before AF ablation. A randomized controlled trial published in JAMA Cardiology compared TEE to ICE in 1,800 patients undergoing AF ablation. The study found no significant difference in thromboembolic events between the ICE and TEE arms (0.4% vs. 0.6%). Thrombus detection was slightly higher with ICE, but the confidence intervals were wide. ICE reduced bleeding from the transeptal puncture and fluoroscopy time. The host notes that the low event rates made it difficult to detect differences between the two techniques. He suggests that a larger trial with three arms (TEE, ICE, and no imaging) is needed to determine the best approach for excluding thrombus before AF ablation. The host mentions that his practice does not routinely image before ablation unless there is a high suspicion of clot.