Transient Ischemic Attack Fast-track and Long-Term Stroke Risk: Role of Diffusion-Weighted Magnetic Resonance Imaging

Abstract

Acute ischemic lesions on diffusion-weighted magnetic resonance imaging (DWI-MRI) are reliable predictors of recurrent stroke at 90 days. However, to date, limited information on transient ischemic attack (TIA) patients with positive DWI lesions for stroke risk from 1 to 5 years is available. In this study, we evaluated the role of positive DWI lesions and vascular risk factors on stroke, cardiovascular death, and mortality at 90 days (T0), 1 year (T1), and 5 years (T2). Moreover, we also evaluated the association between stroke risk and the presence of DWI lesions. We performed an observational study on consecutive patients admitted to the emergency department of San Camillo-Forlanini Hospital, Rome, Italy, from January 2007 to November 2012. Over the study period, 4300 patients with TIA or ischemic stroke were examined by stroke specialists in an emergency room setting within 1 hour from admittance. In 510 of 4300 patients (11.86%), a TIA was diagnosed, and 445 patients satisfy the study inclusion criteria. For all 445 patients, the mean ABCD2 score was 4.35 ± 1.30. Using DWI-MRI, we identified acute ischemic lesions in 185 patients (41.57%). We did not observe any correlation between duration of symptoms, ABCD2 score, and positive or negative DWI lesions. Positivity for DWI was not associated with the presence of diabetes mellitus, hypertension, smoking habit, or age; however, an association with weakness was observed. We documented a time-dependent increase in the absolute risk of stroke: T0: 1.35% (95% confidence interval [CI], .81-2.8); T1: 4.78% (95% CI, 2.88-7.47); T2: 9.02% (95% CI, 4.66-5.70). We did not record any difference in stroke risk in patients with positive DWI lesions: T0: hazard ratio [HR], 1.43; 95% CI, .35-5.88; log-rank P = .60; T1: HR, 1.04; 95%CI, .42-2.61; log-rank P = .91; T2: HR, .83; 95% CI, .25-2.67; log-rank P = .86. This long-term follow-up study in TIA patients documents that both positive and negative DWI patients treated with fast-track had similar long-term risks of stroke.