P4273Patterns of an early platelet response after TAVI are equal for various types and sizes of implanted valves, but its magnitude differs across valve diameters

Background: An early platelet count (PLT) decrease is a common phenomenon after TAVI, and its magnitude is associated with poor outcomes (short and long-term). Purpose: Whether the type or size of an implanted valve has an impact on the pattern and magnitude of PLT response after TAVI is unknown. Methods: Among the consecutive 293 pts (79.9±7.5yrs, 68% female, EuroSCORE=22±12%) treated with TAVI (Aug 2009–December 2016), serial changes in PLT were measured prior to and daily 7 days post procedure. Results: Implanted were Edwards Sapien XT (22.1%, group #1), CoreValve© (38.7%, #2), Edwards Sapien (10.7%, #3), Evolut R™ (14.0%, #4), Lotus Edge™ (14.0%, #5) and Engager™ (0.4%, #6), with diameters of 23 (14.4%), 25 (6.5%), 26 (33.8%), 27 (2.7%), 29 (36.1%) and 31-mm (6.5%). An early PLT drop was seen on day 1, reaching nadir PLT on day 2–3 post procedure (Δ%PLT1=27±14% and Δ%PLTmax=43±15%, both p<0.001, respectively). Patterns of an early PLT response were equal across different types (Fig A) and valve diameters (Fig B). However, Δ%PLTmax was biggest for (#3) Sapien and (#5) Lotus Edge™ (42±16% vs 42±12% vs 46±19% vs 37±15% vs 51±12% vs 42%, p=0.001, respectively for #1–6). Valve types differ with regard to their sizes (26.3±1.9 vs 28.4±1.8 vs 24.8±1.7 vs 28.0±1.6 vs 24.6±1.5 vs 23.0-mm, p<0.001, respectively for #1–6). The valve size, but not its type was related to Δ%PLTmax (B=-1.446, 95% CI -2.656 to -0.236, β=-0.149, p=0.019).