Background:
Left atrial reverse remodeling (LARR) after catheter ablation (CA) to atrial fibrillation (AF) indicates reduction of AF substrates in left atrium (LA). In this study, we investigated the impact of LARR on the outcome after CA of non-paroxysmal AF (non-PAF; persistent AF and long-standing persistent AF) and determined the predictor of LARR.
Methods and Results:
Consecutive 303 patients who underwent initial CA of non-PAF in our institute were retrospectively analyzed. We performed multi-detector computed tomography (MDCT) to evaluate LA end-systolic volume (LAESV) before and 90 days after CA. We determined LARR using %LA reduction [defined as (pre LAESV - post LAESV) / pre LAESV x100]. The average %LA reduction was 20.2±16.8% (median 22.2%). Then we divided them into LARR group (%LA reduction >20%, N=167) and non-LARR group (%LA reduction<20%, N=136). We followed them for 630±153 days to observe their recurrence rate after 90 days blanking period (BP). The recurrence was less frequently observed in LARR group than non-LARR (31.1% vs 56.4%, p<0.01, log-rank test). Next, we examined the predictor of LARR. In univariate analysis, there were no significant differences in age, sex, CHADS2 score, AF duration before CA, anti-arrhythmic drug administration after CA, CA procedure, echocardiographic data and MDCT parameters. Only the recurrence rate during BP was significantly smaller in LARR than non-LARR (43% vs 61%, p=0.002). Then, we divided BP into three parts, early BP, mid BP and late BP (within 7 days, 8 to 30 days, and 31 to 90 days after CA, respectively). The recurrence rate in LARR group was lower than in non-LARR during early BP (27.5% vs 36.8%, p=0.09), mid BP (30.5% vs 42.6%, p=0.03), and late BP (9.0% vs 31.6%, p<0.01). In multivariable analysis, recurrence in late BP revealed to be the predictor of LARR (odds ratio 0.19, [95% confidence interval: 0.10-0.37]).
Conclusions:
The LARR was associated with better clinical outcome. The absence of recurrence during late BP (31-90 days after CA) was the strong predictor of LARR. These parameters can be acquired at the time point of 3 months after CA and they may be useful for predicting the CA results. Recurrence during late BP might be one of the causes of the poor LARR after CA for non-PAF.
Early recurrence during the blanking period and left atrial reverse remodeling after catheter ablation for non-paroxysmal atrial fibrillation
