The investigators will conduct a prospective cohort study at the London Health Sciences Centre, Ontario, Canada. The investigators will identify 15-30 idiopathic TTP patients who have presented with their first episode and are in remission within the last 30 days. They will be followed for 12 months from the time of their remission. Study procedures include routine laboratory monitoring, biomarker assessments, cardiovascular and neurocognitive functional assessments, and non-invasive imaging studies. The long-term follow-up TTP study will help to assess the mechanisms of vascular injuries, evaluate cardiovascular and cerebrovascular monitoring tools, and generate novel ideas to prevent further vascular injuries.