Perioperative thrombocytopenia predicts poor outcome in patients undergoing transcatheter aortic valve implantation

To determine the time point at which thrombocytopenia after TAVI procedure is an indicator of the worst prognosis, with special consideration of perioperative platelet and coagulation activation as its potential causes.

Thirty two patients (mean age 78.5±7.9years, 62% females) qualified for TAVI procedure were prospectively evaluated. Platelet counts were assessed at baseline and for the next three postoperative (POD) days. Platelet activation was evaluated by P-selectin (PS, serum, ELISA) and platelet factor 4 (PF-4, CTAD plasma), and blood coagulation activation by prothrombin fragments 1+2 (F1+2, plasma, ELISA). Composite end point (CEP) including death and the need of cardiovascular rehospitalization was assessed after a mean of 14.1±6.7months.

During the follow up period half of the patients reached CEP. Thrombocytopenia was more profound and frequent in patients with CEP as compared to those without (p<0.05). No differences regarding either the biomarkers of platelet (PS, PF-4) or coagulation (F1+F2) activation between the groups with and without CEP were found. Patients with moderate-to-severe thrombocytopenia at baseline had worse prognosis (log-rank test, p=0.0003). Based on the receiver operating characteristic curve analysis, the differences between platelet count on each postoperative day and the baseline count did not have any predictive value in CEP occurrence.

Patients with thrombocytopenia following TAVI procedure have poor prognosis, however, the changes on the particular days are not more important than initial platelet count. Further studies are needed to evaluate platelet and blood coagulation activation as potential causes of thrombocytopenia and impaired prognosis related to it.