Transcatheter Aortic Valve Implantation Induces Transient Drop in Platelet Reactivity.

Although recent studies described platelet reactivity (PR) changes in days after transcatheter aortic valve implantation (TAVI), precise time course and duration of these changes have not been fully investigated. The aim of this study was to investigate PR pattern during and after TAVI in multiple time points. Study included 40 consecutive patients undergoing TAVI. All patients underwent the procedure on dual antiplatelet therapy. PR was measured in 7 time points: before induction of anesthesia (T1), after heparin administration (T2), 10 minutes after initial valve implantation (T3), at the end of procedure (T4), and on 3rd, 6th, and 30th postoperative day (T5-T7). PR was measured using impedance aggregometer using 3 different platelet aggregation agonists (arachidonic acid in ASPItest, adenosine diphosphate in ADPtest and thrombin receptor activating peptide 6 in TRAPtest). All patients underwent successful TAVI procedure. Mean PR on T1 was 22.9 ± 23.0 U for ASPItest, 40.5 ± 23.7 U for ADPtest and 91.7 ± 32.5 U for TRAPtest. There was no significant difference in PR on T2. On T3, significant reduction of PR in all 3 tests was observed [ASPI 10.4 ± 11.6 U (P = 0.001), ADP 24.2 ± 14.1 U (P < 0.001) and TRAP 69.3 ± 26.6 U (P < 0.001)]. PR nadir for all tests was reached on T5, with subsequent PR incline. PR values in all tests returned to baseline levels on T7. Our results show that successful TAVI procedure induces transient decrease in PR regardless of the platelet activation pathway.