Po-02-135 does la size predict outcomes in af and systolic heart failure?

Significant left atrial (LA) enlargement often accompanies heart failure with reduced ejection fraction (HFrEF) and may determine the success of AF ablation. However, the impact of LA size on long-term outcomes remains unclear. We aim to determine the relationship between LA size and AF recurrence in patients with normal LV function (NLV) and HFrEF following AF ablation. Consecutive patients undergoing index AF ablation across 11 centres were stratified according to baseline LVEF (<50% or >50%). The impact of baseline LA size on 12-month AF recurrence was determined utilising continuous remote rhythm monitoring to detect arrhythmia recurrence and quantify AF burden. 360 patients were included (NLV=237, HFrEF=123). The HFrEF group (mean LVEF 34.9±8.3%) were younger (62±10 vs 65 ± 9 years, p=0.020), with larger LA size (LAVI 54.6±16.5ml/m2 vs 45.4±14.1ml/m2, p<0.001). Despite differences in LA size, freedom from AF was similar in those with and without HF (56% vs 54% respectively, Log Rank p=0.621, figure 1a). Similarly, AF burden did not differ between groups (median burden HFrEF 0% (0-1.1); NLV 0 (0-2.5), p=0.195). An age-matched 1:1 comparison of NLV and HFrEF (N=246) demonstrated no impact of baseline LA size on arrhythmia recurrence (p=0.579), despite larger LA in those with HFrEF (LAVI 54.6±16.5 vs NLV 45.0±15.0, p=0.0002). LA enlargement did not predict arrhythmia recurrence (HR 1.400, 95% CI 0.952-2.057, p=0.086) regardless of HF status (figure 1b). At 12 months, LV function normalised in 80% (LVEF>50%) of those with HFrEF (ΔLVEF: +19±13%, p<0.001) with a significant reduction in LA size (54.6±16.5 to 44.7±14.6ml/m2, p<0.001), comparable in those with and without AF recurrence (p=0.819). Baseline LA enlargement did not influence AF recurrence in those with or without LV recovery (HR 1.622 95% CI 0.702-3.748, p=0.258). LA enlargement did not determine the outcome of AF ablation in those with and without HFrEF. LA size is less useful in guiding patient selection for AF ablation in HFrEF