Quality of Life, Physical and Mental Health of Patients with Vaccine Induced Immune Thrombotic Thrombocytopenia after Extended Followup

Introduction: Vaccine-induced immune thrombotic thrombocytopenia (VITT) is a rare, life-threatening thrombotic disorder that was reported worldwide after vaccination with adenoviral vector-based COVID-19 vaccines in 2021. Initial studies have explored the clinical and laboratory aspects of VITT; however, there is limited data on the long-term outcomes related to quality of life and mental health. In this study, we described physical, cognitive and psychiatric outcomes of patients with VITT in Canada after prolonged follow up.

Methods: We identified patients with VITT in Canada based on samples tested in the McMaster Platelet Immunology Laboratory, the national reference laboratory for VITT testing. Consenting patients were contacted for telephone visits on 2 occasions approximately once per year. At the first follow up, patients answered a series of questions about their general physical and mental health. At the second follow-up, patients provided responses to 4 standardized questionnaires by telephone: the Generalized Anxiety Disorder-7 tool, the Patient Health Questionnaire, the Post Traumatic Stress Disorder (PTSD) Checklist, and the EuroQol-5 Dimensions-5 Levels tool. All patients signed informed consent and the study was approved by the Hamilton Integrated Research Ethics Board.

Results: We identified 46 patients with VITT in Canada. Of those, 19 patients from 5 provinces consented to participate. Median age at VITT diagnosis was 50 years (IQR, 49 - 61 years) and 58% were female. Patients were followed for a median of 38 months (IQR, 34.1 - 38.5 months). All patients experienced one or more thrombotic event during their initial VITT presentation including pulmonary embolism (n=7), cerebral venous sinus thrombosis (n=6), portal vein thrombosis (n=4), arterial thrombosis (n=3), deep vein thrombosis (n=2), splanchnic vein thrombosis (n=1), renal vein thrombosis (n=1) and acute coronary syndrome (n=1).

At the first follow-up (median 17.1 months, IQR 15.4 - 24.2 months), all 19 (100%) patients reported physical symptoms including weight loss, fatigue, visual disturbances, headaches, dizziness, breathing difficulties, body aches, exhaustion with minimal exertion and numbness. 12 (63.2%) patients reported neurocognitive or psychiatric symptoms including brain fog, memory loss, anxiety, panic attacks, PTSD and depression. At the second follow-up (median 38 months, IQR 34.1 - 38.5 months) since initial presentation), 15 (78.9%) patients reported persistent physical symptoms, 10 (52.6%) patients reported neurocognitive or psychiatric symptoms. Based on standardized questionnaires, at the end of follow up, 14 (73.7%) patients had minimal to mild anxiety; 13 (68.4%) patients had minimal to moderate depression; and 2 patients (10.5%) had evidence of PTSD.

Conclusion: After 3 years of follow up, patients with VITT experienced physical, neurocognitive and psychiatric impairments. Persistent symptoms consistent with anxiety, depression and PTSD were common in this cohort.

Arnold:Amgen: Consultancy; Argenx: Consultancy; Medison: Consultancy; Principia: Consultancy; Rigel: Consultancy; Sanofi: Consultancy; Sobi: Consultancy; Novartis: Research Funding; Paradigm: Research Funding.