Procedural outcomes: the evidence is growing.
Interestingly, in this issue of the Journal, Garg et al. showed that no significant differences in clinical and procedural outcomes were observed comparing septal vs. device puncture, apart from total procedural time that was significantly longer with TSP via the closure device vs. the native septum (p = 0.004), mostly due to longer time needed to perform TSP. This suggests a similar maneuverability of the catheters in left atrium with both approaches. Recurrence of AF was not significantly different in the two groups and was comparable to AF ablation outcomes in patients without ASD closure device. As expected, long-term freedom from AF was higher in paroxysmal and persistent AF, while long-standing persistent AF patients were more unlikely to maintain sinus rhythm during follow-up. Considering the high success-rate in the early stages of AF, timing of catheter ablation is crucial and a “wait-and-see ” strategy with a prolonged drug treatment12 is probably not worth it for ASD patients.
Of note, despite different follow-up strategies no residual interatrial shunt was reported in the three cohorts. In a medium-term follow-up (3 to 6 months after the procedure), Santangeli et al .6 relied on contrast transthoracic echocardiography (TTE), with and without Valsalva maneuvers, Li et al. 7 utilized TEE. Sang et al. 8 relied only on non-contrast enhanced TTE, hence we cannot exclude that in this cohort the presence of a residual interatrial shunt might have been missed in some cases. Post-procedural shunts at ICE and contrast TTE were noted in a non-negligible number of patients in the first cohort6; therefore timing and the best strategy for evaluating residual shunts are of great importance. Follow-up in cases with direct puncture of the ASD closure device is even more challenging, because of the so-called “shadow effect ” that might hamper a correct “anatomical” detection of the residual shunt. In our opinion, use of bubble-contrast TTE, enhanced with novel 3D imaging techniques, may be the best follow-up strategy in these patients, minimizing the risks of an incorrect detection of residual shunt, as well as avoiding discomfort of TEE (Figure 1) .
To sum up, despite limited data and a relatively small sample size, this meta-analysis highlights the feasibility and safety of catheter ablation in patients with ASD closure devices. In our opinion, these procedures should be centralized at high-volume centers; use of ICE should be encouraged, and a thorough follow-up with contrast-enhanced echocardiography should be performed. Garg et al. should be applauded for their work, useful to shed some light on this challenging population, establishing that AF ablation in patients with percutaneous atrial septal closure devices is safe and effective, but in the right hands.