Brief Summary
This podcast episode of "This Week in Cardiology" discusses recent studies and their implications for clinical practice. It covers conduction system pacing versus RV pacing, withdrawing heart failure medications after correcting atrial fibrillation, and patient selection for left atrial appendage occlusion. The episode emphasizes the need for careful patient selection and further research to optimize treatment strategies.
- Conduction system pacing shows promise but requires more evidence.
- Withdrawing heart failure meds after AF correction needs careful monitoring.
- Patient selection for left atrial appendage occlusion is crucial to ensure benefit.
Introduction
The host, John Mandola, introduces the topics for this week's podcast, which include conduction system pacing versus regular pacing, withdrawing heart failure medications when atrial fibrillation is corrected, patient selection in left atrial appendage occlusion, and some announcements.
Conduction System Pacing vs. RV Pacing
The CSPACE trial compared conduction system pacing to RV pacing for patients with a pacing indication. Conduction system pacing involves placing a lead in the hiss or left bundle branch block to activate the heart naturally, avoiding the dissynchrony inherent in RV pacing. RV pacing activates the muscle around the lead, spreading depolarization through the RV and then to the LV, leading to dissynchronous contraction. While conduction system pacing allows simultaneous activation of the ventricles, it is technically more challenging, potentially causing perforation and requiring more lead revisions. The CSPACE trial found that conduction system pacing was successful in 88% of patients, compared to 99% for RV pacing, and required longer procedures and more lead revisions. However, after two years, conduction system pacing was associated with a lower composite endpoint of pacing-induced cardiomyopathy and the need for CRT upgrade. The author emphasizes the need for more randomized trials to compare CS pacing versus standard pacing.
Withdrawing Heart Failure Meds After AF Correction
The Withdraw AF RCT investigated whether guideline-directed medical therapy (GDMT) can be stopped in heart failure patients with reduced ejection fraction after correcting atrial fibrillation (AF). The study randomized 60 patients who had recovered from AF and were maintaining sinus rhythm into two groups: early withdrawal of meds (Group A) and delayed withdrawal (Group B), with a crossover design. CMR was performed at crucial periods to assess LV function and scar burden. The primary endpoint was maintenance of LVEF greater than 50% at 6 months. During the first 6 months, 27 of 30 patients in Group A maintained an EF greater than 50%, compared to 100% in Group B. Five patients experienced a reduction in LVEF to below 50% following short-term medication withdrawal, detected on CMR but not on transthoracic echo. AF recurred in 43% of participants. The author concludes that in carefully selected patients with clear AF-related cardiomyopathy, GDMT can be withdrawn with close monitoring for AF recurrence and LV function.
Patient Selection in Left Atrial Appendage Occlusion
A retrospective review of long-term outcomes after left atrial appendage occlusion from the NCDR registry was discussed. The study included nearly 35,000 patients with a mean age of 77 and a high CHA2DS2-VASc score of 4.7. The data showed high death rates of 11% at one year and 44% at five years, significantly outpacing stroke rates. The author argues that these high death rates indicate poor patient selection for the procedure, as many patients die before benefiting from stroke prevention. The author emphasizes the importance of considering competing causes of bad outcomes and avoiding the procedure in patients with frailty, older age, and comorbidities.
Announcements
The host mentions that he will be covering the major studies at the upcoming ESC in Madrid as a medical journalist. He also mentions his written piece on hypertension guidelines is available on the website.
