CRT ‘superior to standard RV pacing’ following ablation of AF
MedWire News: Cardiac synchronization therapy (CRT) may be superior to conventional right-ventricular (RV) pacing for reducing heart failure (HF) events in patients undergoing ablation for atrial fibrillation (AF), a randomized controlled trial suggests.
"Ablate and Pace" - shorthand for atrioventricular junction ablation followed by permanent pacing from the RV apex - is the first-line treatment for patients with severely symptomatic permanent AF.
This strategy is known to offer effective rate control and to improve symptoms in some patients; however, RV pacing is not considered to be optimal because it provides nonphysiologic asynchronous contraction and left ventricular remodeling, which might partially counteract the benefits of rate regularization.
In this study, Michele Brignole (Ospedali del Tigullio, Lavagna, Italy) tested the value of CRT over conventional RV pacing in 186 patients. All had undergone successful AV junction ablation and CRT implantation. They were then randomly assigned to receive optimized echo-guided CRT (n=97) or RV apical pacing (n=89).
The cohort was followed-up for an average of 20 months. During this time, the primary composite endpoint - death from HF, hospitalization for HF, or worsening HF - affected 11% of the CRT group and 26% in the RV group, giving a significant hazard ratio (HR) of 0.37.
Thus, patients treated with CRT were 63% less likely to experience the primary endpoint than those treated with RV pacing. CRT-treated patients were also less likely to experience worsening HF (HR=0.27) or HF hospitalization (HR=0.20), whereas total mortality was similar in the two groups (HR=1.57).
Finally, subgroup analysis confirmed that the benefits of CRT were consistent irrespective of whether patients met eligibility criteria for the device.
Writing in the European Heart Journal, Brignole and co-workers conclude that CRT is "superior to RV apical pacing" but add: "Before CRT becomes a first-line therapy for all patients with permanent AF and AV junction ablation, our results should be confirmed by other trials targeting single specific hard endpoints in specific homogeneous subgroups of patients who do not meet current guideline-based indications."
They also warn that their results "cannot be extrapolated to HF patients with paroxysmal AF scheduled for CRT."
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By Joanna Lyford