Adjunctive coronary sinus isolation (CSI) as part of a de-novo ablation strategy does not confer any additional benefit compared to pulmonary vein isolation (PVI) plus roofline ablation in the treatment of high-burden atrial fibrillation (AF), as per a study presented at this year’s Asia Pacific Heart Rhythm Society (APHRS) Scientific Sessions (26–29 September, Sydney, Australia).
Findings from the study in question have also been published in JACC: Clinical Electrophysiology by Prashanthan Sanders (Royal Adelaide Hospital, Adelaide, Australia) and colleagues.
“The coronary sinus (CS) is an arrhythmogenic structure which can initiate and maintain AF,” the authors initially note. “CS ablation has been shown to be effective in prolonging the AF cycle length, and terminating AF in patients with both paroxysmal and persistent AF who have persistent AF after PVI.”
With this context in mind, Sanders et al undertook a randomised controlled trial to investigate the efficacy of CSI as an adjunctive ablation strategy for the treatment of high-burden AF. They enrolled consecutive patients presenting with symptomatic, long episodes of paroxysmal AF (≥48 hours to ≤7 days) or persistent AF (>7 days to ≤12 months) referred for first-time ablation. These patients were randomised to either PVI, roofline and CSI ablation, or PVI and roofline ablation only, and assessed post-procedurally via clinical follow-up and seven-day Holter monitoring at regular intervals.
The primary outcome of the study was single-procedure, drug-free atrial arrhythmia-free survival at two years, the authors report.
A total of 100 patients were recruited to the study, with 48 being randomised to the ‘CSI group’ and 52 randomised to the ‘non-CSI group’.
Sanders and colleagues relay that acutely successful CSI ablation was achieved in 45 of the 48 patients in the CSI group. At two-year follow-up, 30 of 48 patients (62.5%) in the CSI group and 33 of 52 (63.4%) in the non-CSI group were free from arrhythmia recurrence. In addition, single-procedure drug-free survival at two years was no different between the two groups (p=0.91)—nor was multiple-procedure drug-assisted survival at five years (p=0.8). Complication rates were not significantly different between groups either (p=0.19), according to the researchers.
“The study showed that empirical [CS] isolation is not useful,” Sanders told Cardiac Rhythm News. “However, there may be selected cases where there are clear triggers or drivers identified within this structure where CSI may be useful. Perhaps, as we develop a more personalised approach, there may still be a role for CSI [ablation].”
