PARAMETERS OF ALLERGIC REACTION AFTER IMPLANTATION OF DIFFERENT PATENT FORAMEN OVALE OCCLUDERS - A PILOT PROSPECTIVE RANDOMIZED STUDY

Primary endpoint
To compare parameters of the allergic response after transcatheter closure of the patent foramen ovale (PFO) using three different types of nitinol occluders in a pilot randomized trial.

Patient population and methods
39 patients aged 29-72 (21 women and 18 men) who met institutional criteria for catheter based PFO closure were included in the study. Patients were divided into three groups according to the type of implanted occluder: 1. Amplatzer® (Abbott®) device made of nitinol with wire treatment to reduce nickel excretion and polyester fabric; 2. Figulla® device (Occlutech®) made of titanium oxide-coated nitinol and PET-patch; 3. the Ultrasept® (Cardia®) device which consists of nitinol coated with polyvinyl alcohol. Plasma CRP levels, full blood count including eosinophils, IgE, eosinophilic cationic protein (ECP), fibrinogen and a panel of cytokines were measured at baseline (24 hours before the procedure) and 6 hours, 24 hours, 7 days, 1 month and 6 months after occluder implantation.

Results
Only patients with normal baseline levels of IgE, eosinophils, ECP, and CRP were included for the final analysis (group 1 n = 7, group 2 n = 9, group 3 n = 6). Procedural success was 100% and there were no major complications. No significant changes in plasma levels of IgE and eosinophils were detected during the follow-up among the 3 groups of patients. The ECP values differed statistically among the individual groups 7 days after the procedure (p = 0.025), there were no significant deviations in the other observed times. No measurable increase in interleukins 1 and 6 was detected.

Conclusion
Despite the reported different manufacturing processes of the nitinol PFO occluders, there were no significant differences among the selected parameters of the allergic response immediately after implantation or during the six-month follow-up period.