High morbidity and early readmissions in thrombotic thrombocytopenic purpura requiring intensive care: Insights from a national database

Abstract Introduction: Thrombotic thrombocytopenic purpura (TTP) is a rare but life-threatening thrombotic microangiopathy characterized by severe ADAMTS13 deficiency. Data on intensive care unit (ICU) admissions for TTP is limited yet understanding the clinical course of these critically ill patients is essential to improving outcomes. This study evaluates patient demographics, management strategies, complications, and 30-day readmission rates among ICU admissions for TTP. Methods: The Nationwide Readmissions Database (NRD) was used to identify adult patients with a primary TTP diagnosis requiring ICU admission from 2020-2021. COVID-19 positive cases were excluded. We assessed patient characteristics, in-hospital mortality, major complications, and therapeutic interventions during the index hospitalization. Caplacizumab utilization was analyzed only for 2021 due to ICD-10 code availability. Thirty-day readmission rates were calculated. Analyses were performed using STATA 18.0, with adjustments for the NRD's complex survey design. Results: A total of 492 ICU admissions for TTP were identified from January through November. Females comprised the majority (60.3%) of cases and mean patient age was 49.0 years (median 48.0, IQR: 35-62). Major complications included acute myocardial infarction (14.9%), acute ischemic stroke (13.2%), ventricular tachycardia (2.6%), and supraventricular tachycardia (2.9%). Acute kidney injury developed in 54.7% patients with 12.3% requiring hemodialysis. Additionally, 29.9% of patients required intubation, 32.6% needed mechanical ventilation, and 7.5% received vasopressor support. Plasmapheresis was performed in 62.2% of cases, while Caplacizumab use was limited to 6.4%. Overall in-hospital mortality reached 17.3%. Among 407 survivors, 90 patients (22.2%) were readmitted within 30 days, with a mean time to readmission of 10.4 days. Conclusion: TTP admissions were more common in females and characterised by a median patient age of 48 years. Critical care admissions for TTP are associated with high morbidity, frequent cardiovascular and renal complications, and substantial mortality despite widespread plasmapheresis use. Early readmission rates remain considerable, highlighting the need for improved post-discharge care and strategies to reduce early rehospitalizations. Further, the limited utilization of Caplacizumab highlights potential gaps in adopting newer therapies.