Complications of Atrial Fibrillation Ablation

When Prevention Is Better Than Cure

Antonio Sorgente; Gian-Battista Chierchia; Carlo de Asmundis; Andrea Sarkozy; Lucio Capulzini; Pedro Brugada


Europace. 2011;13(11):1526-1532. 

In This Article

Thromboembolic Events

Many studies have investigated the incidence of thromboembolic events (including transient ischaemic attacks and major strokes) during or after AF catheter ablation. The introduction of open-irrigated catheters and the use of early and aggressive heparinization have reduced significantly the risk of cerebrovascular events related to the procedure,[46–48] even though is not clear if the benefit is shifted more towards late cerebrovascular events than the periprocedural ones. Even though Scherr et al.[49] evidenced an incidence of 1.4% of periprocedural thromboembolic events using an open-irrigated catheter, more robust data are needed to demonstrate a benefit of these catheters over the non-irrigated 4 mm ones. On the other hand, a multicentre retrospective study examined rates of stroke after catheter ablation of AF and, surprisingly, over a follow-up of about 2 years and a half, no difference in thromboembolic events was noted between patients who withdrew oral anticoagulation and patients who continued to be anticoagulated.[50]

As evidenced in studies using intracardiac echocardiography,[41–43] activated clotting time >300 s and high-flow perfusion of the transseptal sheath are mandatory to reduce thromboembolic complications during AF catheter ablation. Furthermore, as already-stated above,[40] continuous administration of warfarin all along the procedure without bridging with low-molecular weight heparins could help in reducing the incidence of stroke and transient ischaemic attacks without affecting the number of bleeding complications.

To complicate matters further, a recent study by Gaita et al.[51] aimed to assess the thromboembolic risk (both silent and clinically evident) associated with AF catheter ablation using pre- and post-procedural cerebral magnetic resonance imaging. The authors reported an incidence of clinically manifest thromboembolic events comparable to what was already demonstrated in the previous studies on the topic (0.4%), but, at the same time, evidenced clinically silent embolic lesions in 14% of patients undergone AF catheter ablation. Anticoagulation degree and electrical or pharmacological cardioversion during the procedure were significantly correlated with silent cerebral embolism.

Open questions remain still on the way. Indeed, further studies are needed to assess any potential increase or decrease of thromboembolic risk associated with 'one-size-fits-all' devices such as a cryoballoon, laser balloon, Mesh™ ablator or Ablation FrontiersTM ablator. To this aim, the MACPAF study will compare the efficacy and the safety of cryoballoon ablation vs. mesh ablation in patients with drug-refractory paroxysmal AF.[52] Furthermore, it is still unknown if therapeutic international normalized ratios, which demonstrated to reduce the incidence of periprocedural stroke,[40] could also replace completely full intraprocedural heparinization.