Transient Ischemic Attack Treatment Strategy Changes May Have Led to Lower CV Events Risk

Introduction: Transient Ischemic Attacks and Cardiovascular Events Risk

Patients who experienced a transient ischemic attack (TIA) had a lower risk of cardiovascular (CV) events than previously reported, according to research published in the New England Journal of Medicine.

Studies conducted in the late 1990s and early 2000s reported that risk of stroke or an acute coronary syndrome after a TIA or minor stroke was 12% to 20%. However, as the investigators of the current study pointed out, there have been major changes in the management of patients with TIA. These changes make it important to re-evaluate patient prognoses and risk stratification.

The TIAregistry.org Project

The TIAregistry.org project investigators sought to estimate the 1-year risk of stroke and composite outcome of stroke, acute coronary syndrome, or death from CV causes. They also evaluated the association of the ABCD² (age, blood pressure, clinical findings, duration of symptoms, and presence or absence of diabetes) score for stroke risk (range 0 to 7), brain imaging findings, and TIA or minor stroke cause with recurrent stroke risk over a 1-year period.

The TIAregistry.org project is an international registry composed of patients who have recently had a TIA or minor stroke designed to describe “the contemporary profile, etiologic factors, and outcomes in patients with a TIA or minor ischemic stroke who receive care in health systems that now offer urgent evaluation by stroke specialists.”

A total of 4789 patients from 61 sites in 21 countries were enrolled in the study from 2009 through 2011.  All patients had a TIA or minor stroke within 7 days before evaluation by stroke specialists and had a focal retinal or brain ischemia with resolution of symptoms or minor strokes with a modified Rankin scale score of 0 or 1.

The primary study outcome was a composite outcome including death from CV causes, non-fatal stroke (ischemic or hemorrhagic), and nonfatal acute coronary syndrome (myocardial infarction, with or without ST-segment or unstable angina followed by urgent catheterization). Secondary outcomes were individual components of the primary, TIA recurrence, death from any cause, and bleeding.

A majority of patients (n=4013; 87.6%) sought medical attention within 24 hours after onset of symptoms, and 89.5% of these patients (n=3593 or 78.4% included in this analysis) were examined by stroke specialists within 24 hours. Weakness (55.0%) and speech abnormalities (48.3%) accounted for the 2 most frequent clinical symptoms. Those patients with a higher ABCD² score were seen by a stroke specialist within 24 hours compared to those patients seen after 24 hours. The mean ABCD² scores were 4.7 ± 1.5 in patients seen within 24 and 3.8 ± 1.6 in those patients seen after 24 hours (P<.001).

Upon evaluation, 5.0% of patients received a new diagnosis of atrial fibrillation; 66.8% of whom received anticoagulant therapy prior to discharge. In addition, a carotid stenosis of 50% or more was discovered in 15.5% of the patients and of those patients, 26.9% of whom underwent carotid revascularization prior to discharge.