Cryoenergy is an emerging technique for the treatment of paroxysmal atrial fibrillation (AF) and atrioventricular nodal reentrant tachycardia (AVNRT). It's unclear whether left atrial ablation procedures with anticoagulation cautions have more thrombogenic effects than right atrial ablation procedures. In the vasculature, procoagulant microparticles (MP) are reliable markers of vascular damage.

We sought to measure procoagulant MP before and 24h after AF and AVNRT cryoablation procedures.

Venous blood samples were collected from patients before and 24h after AVNRT cryoablation (n=10); and before and 24h after AF cryoablation (n=15). Endothelial (EMP), platelet derived-MP (PMP), and concentrations of prothrombin fragment 1+2 (F 1+2) were analyzed in both groups. EMP rose from 15.04 to 30.2/μL in AVNRT group versus 2.61 to 5.63/μL in AF group. PMP decreased in both groups, respectively from 2280 to 942/μL (-59%) in AVNRT group, and from 1281 to 1079/μL (-16%) in AF group. F 1+2 were stable in AVNRT group (190.7 to 203.2pmol/L; + 7%), but increased after AF ablation (75.4 to 141.8pmol/L; + 88%). Variations observed after the procedure for each marker weren’t statistically different between the 2 groups, respectively for EMP (p=0.554), PMP (p=0.379), and F 1+2 (p=0.091).

Using biologic markers of vascular damage, AF cryoablation is not associated with important release of prothrombotic MP, as compared with a shorter procedure like AVNRT cryoablation in right-side chamber.