Predictor and Mid-Term Outcome of Clinically Significant Thrombocytopenia After Transcatheter Aortic Valve Selection

The frequency and predictors of thrombocytopenia after transcatheter aortic valve implantation (TAVI) are unclear.

This study enrolled 342 patients undergoing TAVI (245 with a percutaneous transfemoral approach, 65 with transfemoral surgical cutdown, and 32 with a non-transfemoral approach). Balloon-expandable and self-expanding valves were implanted in 235 and 107 patients, respectively. Platelet counts started to drop immediately, reaching a nadir 2-4 days after TAVI. Clinically significant thrombocytopenia (CSTP) was defined as a platelet count ≤50×10⁹/L at the time of the nadir or both a platelet count between 80 and 51×10⁹/L and a decrease in platelet count ≥50%. CSTP occurred in 16.7% patients. Approach site and TAVI valve selection significantly predicted CSTP. In multivariate analysis, independent predictors of CSTP were liver cirrhosis (odds ratio [OR] 7.22; 95% confidence interval [CI] 1.05-49.82), baseline platelet count ≤120×10⁹/L (OR 2.98; 95% CI 1.20-7.38), multiple blood transfusions (OR 4.03; 95% CI 1.72-9.41), and the use of balloon-expandable valves (OR 2.38; 95% CI 1.04-5.46). Kaplan-Meier survival analysis with a generalized Wilcoxon test revealed that mid-term (2 years) mortality was greater for patients with than without CSTP (31.4% vs. 15.5%; P=0.008).

TAVI-related CSTP was not rare and was associated with poor mid-term outcomes. CSTP was not only caused by patients' comorbidities and TAVI complications, but also related to TAVI procedural factors.