Ablation plus CRT superior to drug therapy in patients with permanent AF, narrow QRS
Rate control with AV junction ablation plus biventricular pacing improved survival among patients with permanent atrial fibrillation, narrow QRS and a prior HF hospitalization compared with medical rate control therapy, a speaker reported.
“The RACE 2 trial failed to show a benefit of a stricter drug rate control vs. a lenient drug rate control, and there was a trend toward worse outcomes with strict rate control. And large meta-analyses of randomized trials showed that beta-brokers add no beneficial effect on survive in patients with atrial fibrillation,” Michele Brignole, MD, of the department of cardiology, Ospedali del Tigullio, Lavagna, Italy, said during a presentation at the European Society of Cardiology Congress. “We previously showed that AV junction ablation plus biventricular pacing was better than right ventricular pacing with regard to the combined endpoint of heart failure hospitalization and worsening heart failure.
“Based on this background, the hypothesis of the APAF-CRT trial was that rate control by AV junction ablation and biventricular pacing is superior to rate control by pharmacological therapy in patients with severely symptomatic permanent AF lasting for more than 6 months, unsuitable for AF ablation or in which AF ablation had failed,” he said.
This trial was an extension of a prior study published in the European Heart Journal in 2018 that looked at AV junction ablation and cardiac resynchronization therapy compared with pharmacological rate-control therapy in patients with permanent AF and narrow QRS ( 110 ms). In the 2018 study, ablation plus CRT reduced the risk for the primary endpoint was HF hospitalization and worsening HF compared with pharmacological therapy (HR = 0.38; 95% CI, 0.18-0.81; P=.013).
For the APAF-CRT trial, researchers enrolled 133 patients (mean age, 73 years; 47% women) with permanent AF and narrow QRS. Participants were randomly assigned to undergo rate control via either ablation and CRT or pharmacological therapy; however, for this analysis, the primary outcome of interest was all-cause mortality.
Participants in the APAF-CRT trial were also stratified by EF ( 35% or > 35%).
According to the study, the trial was stopped for efficacy at an interim analysis after a median of 29 months of follow-up per patient.
Patients who underwent ablation plus CRT experienced lower risk for all-cause death compared with the pharmacological rate control group (11% vs. 20%; HR = 0.26; 95% CI, 0.1-0.65; P = .004; log-rank P = .006).
The survival benefits of ablation plus CRT were consistent regardless of baseline EF (HR for EF 35% = 0.34; 95% CI, 0.06-1.92; P = .22; log-rank P = .11; HR for EF > 35% = 0.27; 95% CI, 0.08-0.84; P = .024; log-rank P = .035).
The results were simultaneously published in the European Heart Journal.
“The benefit [of ablation plus CRT] was due to the combination of strict rate control and rate regularization achieved by AV junction ablation together with biventricular pacing, which counteracted the adverse effects of right ventricular pace,” Brignole said during the presentation. “APAF-CRT results support ablation plus CRT as a first-line therapy in patients with permanent atrial fibrillation and narrow QRS who were previously hospitalized for heart failure.”
References:
- Brignole M, et al. Eur Heart J. 2021;doi:10.1093/eurheartj/ehab569.
- Brignole M, et al. Eur Heart J. 2018;doi:10.1093/eurheartj/ehy555.
Perspective
Back to TopThe take-home message for this study is that for patients with permanent symptomatic AF, a narrow QRS complex and a recent HF hospitalization, CRT plus AV node ablation is a superior strategy compared with ongoing rate control alone.
The study adds an important message: We cardiologists should be more aggressive in referring for CRT and AV node ablation in patients with HF and permanent AF, regardless of baseline EF. Prior to this study, most patients with a narrow QRS, permanent AF and HF had been managed with rate-controlling agents alone. Oftentimes, AV node ablation and CRT were not considered, given the invasive and irreversible nature of the procedure, especially in patients where rate control has been reasonable. This study not only suggests that many patients would benefit from CRT and AV node ablation but also that the procedure has an acceptable safety profile.
In the study, the mean heart rate was 101 to 103 bpm, suggesting somewhat less than ideal rate control. Whether this strategy would be as effective in patients with better baseline rate control or even in slowly conducting AF is unclear. Also, whether conduction system pacing with a left bundle branch lead and AV node ablation would have been even better than traditional CRT is also unclear.
While the results of this trial are intriguing, ultimately CRT AV node ablation is an invasive strategy such that patient comorbidities and the overall risks for an individual patient need to be weighed carefully.
Collapse
Brignole M, et al. Hot Line: APAF-CRT. Presented at: European Society of Cardiology Congress; Aug. 27-30, 2021 (virtual meeting).