High-spatial-resolution delayed enhancement MR imaging allows noninvasive identification of scar induced by RF ablation following isolation therapy of the PV.

Objectives We sought to evaluate radiofrequency (RF) ablations lesions in atrial fibrillation (AF) patients using cardiovascular magnetic resonance (CMR), and to correlate the ablation patterns with treatment success. Background RF ablation procedures for treatment of AF result in localized scar that is detected by late gadolinium enhancement (LGE) CMR. We hypothesized that the extent of scar in the left atrium (LA) and pulmonary veins (PV) would correlate with moderate-term procedural success. Methods Thirty five patients with AF, undergoing their first RF ablation procedure, were studied. The RF ablation procedure was performed to achieve bi-directional conduction block around each PV ostium. AF recurrence was documented using a 7 day event monitor at multiple intervals during the first year. High spatial resolution 3D LGE CMR was performed 46±28 days after RF ablation. The extent of scarring around the ostia of each PV was quantitatively (volume of scar) and qualitatively (1-minimal, 3-extensive and circumferential) assessed. Results Thirteen (37%) patients had recurrent AF during the 6.7 ± 3.6 month observation period. Paroxysmal AF was a strong predictor of non-recurrent AF (15% with recurrence vs. 68% without, p=0.002). Qualitatively, patients without recurrence had more completely circumferentially scarred veins (55% vs. 35% of veins, p = NS). Patients without recurrence more frequently had scar in the inferior portion of the right inferior PV (RIPV) (82% vs. 31%, p=0.025, Bonferroni corrected). The volume of scar in the RIPV was quantitatively greater in patients without AF recurrence (p=<0.05), and was a univariate predictor of recurrence using Cox regression (p=0.049, Bonferroni corrected). Conclusions Among patients undergoing PV isolation, AF recurrence during the first year is associated with a lesser degree of PV and LA scarring on 3D LGE CMR. This finding was significant for RIPV scar, and may have implications for the procedural technique used in PV isolation.

No abstract

Background: Circumferential pulmonary vein ablation (CPVA) has become common therapy for atrial fibrillation (AF), but results of large randomized controlled trials comparing this procedure with antiarrhythmic drug therapy (ADT) have not been published to date. We conducted a systematic literature review to assess whether CPVA is superior to ADT for the management of AF. Methods: We searched PubMed, EMBASE, and the Cochrane Central Register of Controlled Trials for relevant randomized controlled trials. Data were abstracted to construct a 2ϫ2 table for each trial. Recurrence of any atrial tachyarrhythmia (AT) was considered the primary end point of the trials. The estimate and confidence interval for the pooled risk ratio of AT recurrencefree survival in the CPVA group vs the ADT group were obtained using the random-effects model. Results: Four trials qualified for the meta-analysis. In total, 162 of 214 patients (75.7%) in the CPVA group had AT recurrence-free survival vs 41 of 218 patients (18.8%) in the ADT group. The random-effects pooled risk ratio for AT recurrence-free survival was 3.73 (95% confidence interval, 2.47-5.63). In addition, fewer adverse events were reported in the CPVA group compared with that in the ADT group. Conclusions: We observed statistically significantly better AT recurrence-free survival with CPVA than with ADT. These results highlight the need for larger trials to determine the appropriate role for CPVA in the management of AF. Ongoing clinical trials may provide further guidance on these treatment options for AF.