Incidence and Clinical Outcomes of Thrombocytopenia after Transcatheter Aortic Valve Replacement in Thai Patients

Abstract

Background: Post-transcatheter aortic valve replacement (TAVR) thrombocytopenia has been reported to be a predictor of higher mortality and worse clinical outcomes in published studies mostly from Western countries; however, data from Asian countries are generally limited, while data from Thai population are lacking. Objective: To evaluate the incidence and outcomes of Thai patients who developed thrombocytopenia after TAVR. Materials and Methods: The present research was a retrospective observational study. The authors collected data from patients underwent TAVR at Siriraj Hospital between 2009 and 2019. The patients were stratified into four groups according to nadir platelet count, no thrombocytopenia with platelet of 150,000/uL or more, mild with platelet of 100,000 to 149,999/uL, moderate at 50,000 to 99,999/uL and severe at less than 50,000/uL. In addition, the patients with moderate to severe thrombocytopenia were stratified into two groups according to the percentage decline in platelet count (DPC) post procedure as DPC of less than 50% or DPC of 50% or more from the baseline platelet count. Results: Eighty-three patients were reviewed. One patient who died intraoperatively was excluded. Thrombocytopenia occurred in 62 patients (75.6%), in which 36.6% (n=30) of the cases were classed as moderate, and 8.5% (n=7) as severe thrombocytopenia. The platelet count returned to baseline before discharge or during the follow-up period in 83.8% (n=52) of patients. The incidence of in-hospital mortality was significantly higher in patients with severe thrombocytopenia than those with mild thrombocytopenia at 28.6% versus 4% (p=0.011). The duration of admission, length of stay in the CCU, incidence of life-threatening bleeding, clopidogrel discontinuation, platelet transfusion, rate of infection, shock, and acute kidney injury were also significantly higher in patients with moderate to severe thrombocytopenia. Conclusion: Acquired thrombocytopenia after TAVR is a common phenomenon in Thai patients (75%) but usually transient with a nadir platelet count greater than 50,000/uL. Most patients had spontaneous platelet recovery. The presence of severe thrombocytopenia with a nadir platelet count of less than 50,000 is a red flag sign for concomitant infection. The severity of thrombocytopenia is significantly associated with higher mortality and post-procedural adverse events. Keywords: Thrombocytopenia; Transcatheter aortic valve replacement (TAVR)