Low α2-plasmin Inhibitor Antigen Levels on Admission Predict Unfavorable Outcomes in Acute Ischemic Stroke Patients Treated With Intravenous Thrombolysis
Every year, more than 795,000 people in the United States have a stroke. Numbers translate to the following frightening statistics: Every 40 seconds, one person suffers from a stroke. Every four minutes, one of these individuals dies. Approximately 87% of all strokes are ischemic strokes, in which thrombotic vascular occlusion occurs. Establishing the balance between risk and benefit is the impetus for ongoing randomized clinical trials of thrombolysis in minor stroke. Acute treatment for ischemic strokes aims to restore brain tissue perfusion. Restoration is achieved medically using a thrombolytic drug, intervention with endovascular treatment, or both. High blood levels of α2-antiplasmin, an ultrafast, covalent inhibitor of plasmin, have been linked to an increased risk of ischemic stroke. Only a few of the total population of patients with ischemic stroke are eligible for acute therapy because the stroke is either nondisabling or contraindications to thrombolysis exist. Approximately 25% of all ischemic strokes are eligible for medical thrombolysis and 10%-12% are eligible for endovascular treatment.
Zsuzsa Bagoly, M.D., Ph.D., of the University of Debrecen in Debrecen, Hungary, stated on Sunday during the Fibrinolysis and Proteolysis virtual session that intravenous thrombolysis by recombinant tissue plasminogen activator (rt-PA) fails to achieve recanalization in a large subset of acute ischemic stroke (AIS) patients, while in approximately 6%-8% of cases, intracerebral hemorrhage (ICH) occurs. As such, Bagoly and team sought to find out if there was a linkage in the ability to predict outcomes in AIS patients based on α2-plasmin inhibitor levels.
In the prospective observational study, blood samples from 421 AIS patients undergoing rt-PA were examined. Median α2-PI activity and antigen levels showed a significant drop immediately post lysis and increased to subnormal levels at 24 hours post event. α2-PI levels on admission showed a significant negative stepwise association with stroke severity. Patients with favorable long-term outcomes had significantly higher on-admission α2-PI antigen levels (median: 61.6 [IQR 55.9-70.5] mg/L) as compared with patients with poor outcomes. Bagoly remarked that a low α2-PI antigen level on admission is a predictor of unfavorable long-term outcomes (functional disability or death) in AIS patients undergoing thrombolysis.
Read the full abstract here.