Abstract 4136085: The Prognostic Impact of Thrombocytopenia at 6 months after Transcatheter Aortic Valve Replacement: A Retrospective Multicenter Study

Background: Transient thrombocytopenia after transcatheter aortic valve replacement (TAVR) is a common phenomenon. Thrombocytopenia after TAVR during the perioperative period has been reported to impact prognosis. However, the impact of thrombocytopenia in the mid-term post-TAVR period is currently unknown. Methods: A retrospective observational study was conducted on 1405 patients who underwent TAVR from May 2016 to February 2023 at four institutions. Of these, 850 patients were analyzed. Patients who underwent dialysis (67), converted to an open chest surgery (8), had a Valve-in-Valve procedure (30), underwent a direct aortic approach (16), had a malignant tumor (66), and patients whose platelet levels could not be measured at 6 months after TAVR due to death or dropout were excluded from the analysis. The clinical follow-up occurred at 1, 6, and 12 months after the procedure. Laboratory testing was conducted before TAVR, during the perioperative period, 1 month post-procedure, and 6 months later. The decrease in platelet count (DPC) 6 months after TAVR was calculated by the following formula: [(Baseline platelet – 6 months platelet)/baseline platelet *100]. A receiver operating characteristics curve was plotted for all-cause mortality at 1 year and DPC at 6 months. The calculated cutoff value for the DPC at 6 months (28.68%) was utilized to classify and compare the two groups. Multivariate logistic regression models were also used to examine the association between the DPC at 6 months and all-cause mortality at 1 year. Adjusted for propensity score matching, the DPC was compared at 6 months in self-expandable and balloon-expandable prosthetic valves. Result: Of the 850 eligible patients (age: 85.5 ± 4.9 years), 31 (3.4%) died between 6 months and 1 year after TAVR. The DPC at 6 months after TAVR was 11.9 ± 22.5%. Multivariate logistic regression analysis including the DPC at 6 months, age, gender, and STS score showed that the DPC at 6 months was independently associated with all-cause mortality at 1 year (odds ratio: 1.03, 95% confidence interval: 1.005-1.046, p=0.01). After adjustment for propensity score matching, the balloon-expandable prosthetic valve had a higher rate of thrombocytopenia at 6 months (15.0% vs. 9.6%, p=0.04). Conclusion: The DPC at 6 months after TAVR may predict all-cause mortality at 1 year.