Transcatheter aortic valve implantation (TAVI) is sometimes followed by an unexplained drop in platelet count, known as platelet count reduction (PR). Previous research suggests that patients receiving balloon-expandable valves (BEVs) experience a greater PR compared to those with self-expandable valves (SEVs). To better understand this phenomenon, a study was conducted to examine the incidence and clinical impact of PR after TAVI.

The study included 1,122 adult TAVI patients, with 632 matched in a 1:1 ratio between BEV and SEV recipients for analysis. Using a mixed regression model, researchers observed that platelet counts in all patients followed a parabolic curve after the procedure, with the lowest point typically occurring around three days post-implantation. No significant difference was found between BEV and SEV groups in the extent of platelet count reduction.

Notably, 14.6% of patients developed severe thrombocytopenia, with platelet counts dropping below 100,000/µL. However, the occurrence was similar between the two valve types. Importantly, thrombocytopenia was associated with higher risks, including increased need for blood transfusions, longer ICU and hospital stays, and greater in-hospital mortality.

The findings highlight that TAVI, regardless of valve type, leads to a significant but temporary drop in platelet counts. This condition poses serious risks, emphasizing the need for further research to uncover its causes and clinical implications.