LAUSR

To the Editor: Patients undergoing atrial fibrillation (AF) ablation (abl) are subject to an enhanced sensitivity to irritative stimuli in the context of a high level of endocardial inflammation in the course of the first 3 months following the ablation procedure, so-called blanking period [1]. In this regard, by meta-analysis of the studies that tested corticosteroid anti-inflammatory therapy in ablated patients [1–5], it was possible to deduce some interesting inference. As is well known, during the blanking period, patients are affected by a very pronounced arrhythmic diathesis that requires the use of antiarrhythmics (Vaughan Williams class IC drugs, sotalol, amiodarone, etc.) for the prevention of AF relapses. The novelty consists in the fact that for the prophylaxis of AF recurrences during the blanking period, so-called early AF recurrences, in some studies [1–5], the corticosteroids were tested. The results were quite contradictory. In fact, based on my meta-analysis, involving three studies focusing on the prevention of early AF recurrences, a significant preventive effect against AF (pooled OR, 0.6; 95% CI, 0.39, 0.93; p = 0.02) (please see Fig. 1) has been demonstrated only with the use of corticosteroids at moderate doses (0.5 mg/kg of methylprednisolone sodium succinate administered intravenously during the procedure and the next day, followed by oral methylprednisolone 12 mg per day for the subsequent 4 days [1]). Instead, the use of corticosteroids at low doses has been ineffective. In addition, among the s tud ies tha t have reso r t ed to the Bmodera te^ corticosteroid doses (Fig. 1), only the study of Kim et al. [1] has been indicative of a corticosteroid efficacy, while the other two studies included in the metaanalysis have exhibited either a nonsignificant trend toward a preventive effect [2] or a neutral effect [4], respectively. In any case, the abovementioned pooled OR (Mantel-Haenszel, fixed, 95% CI) indicates a significant protective effect exerted by corticosteroid moderate doses against early AF recurrences. In this scenario, however, a relatively high heterogeneity should also be underlined (I = 63%). On the contrary, corticosteroids do not show any significant protection against late AF recurrences, i.e., those occurring after the third month, irrespective of the used dosage (pooled OR, 0.83; 95% CI, 0.61, 1.12; p = 0.23). Lessons to be derived from this data include the awareness that AF, after its interruption by means of abl, can be reinstated as a consequence of a highly inflamed atrial environment due to the presence, in particular, of a high level of inflammatory cytokines [2, 6]. This indirectly underlines the importance of inflammation in the genesis of early relapses of AF, as a trigger of electrical instability, which is paradoxically elicited by the therapeutic modality (AF abl) in itself. In addition, the fact that controls taking placebo were used rather than controls treated with antiarrhythmic drugs is actually an important limitation of these studies. Thus, it can be said that for prophylaxis of Bearly^ AF recurrences, namely those occurring within the first 3 months after AF ablation, corticosteroids at moderate doses would seem to have the potential for halting and/or hindering these events, whereas the evidence that this measure is a valid alternative to the use of antiarrhythmics is lacking. Actually, no head-to-head comparisons have been made yet between corticosteroids at moderate doses and antiarrhythmics for the prevention of early AF recurrences. * Renato De Vecchis [email protected]