The Barcelona-Asymptomatic Intracranial Atherosclerosis (AsIA) study: Subclinical cervico-cerebral stenosis and middle cerebral artery pulsatility index as predictors of long-term incident cognitive impairment.

BACKGROUND AND AIMS: We aimed to study subclinical non-invasive vascular markers as predictors of incident long-term cognitive impairment in a longitudinal population-based study. METHODS: The Barcelona-Asymptomatic Intracranial Atherosclerosis (AsIA) study is a population-based study that included a random sample of 933 Caucasian subjects (mean age 66 years, 64% male) with a moderate-high vascular risk and without history of stroke or dementia. Subclinical carotid and intracranial stenosis was assessed at baseline visit by cervical and transcranial color-coded duplex (TCCD) and confirmed by magnetic resonance angiography. Cervico-cerebral stenosis (CCS) was defined as the presence of extra and/or intracranial stenosis >50%. Baseline middle cerebral artery pulsatility index (MCA-PI) was measured bilaterally by TCCD, and mean PI of both sides was considered for analyses. Subjects were followed-up to determine incident long-term cognitive impairment (mild cognitive impairment or dementia). RESULTS: After a median of 7.16 [6.91-7.75] years of follow-up, 91 subjects (9.7%) developed cognitive impairment, 27 of them mild cognitive impairment, and 64 dementia. Incidence of cognitive impairment was significantly higher among subjects with subclinical CCS (21.4% versus 9% in those without CCS) and among those with mean MCA-PI>1 (13.5% versus 7.4% in those with MCA-PI<1). In multivariate Cox regression analyses, both CCS and MCA-PI>1 were independently associated with incident cognitive impairment with HR of 2.07 [1.11-3.88] and 1.58 [1.02-2.46], respectively. CONCLUSIONS: Subclinical cervico-cerebral stenosis and higher MCA-PI are non-invasive neurosonological markers of incident long-term cognitive impairment in our population.

Metabolic syndrome and resistance to IV thrombolysis in middle cerebral artery ischemic stroke.

OBJECTIVE: The metabolic syndrome (MetS) is a cluster of vascular risk factors associated with a prothrombotic state. We aimed to evaluate the impact of MetS on the response to systemic tPA treatment in patients with acute middle cerebral artery (MCA) ischemic stroke. METHODS: We studied 100 consecutive patients with ischemic stroke with MCA occlusions on prebolus transcranial Doppler (TCD) examination treated with tPA following SITS-MOST criteria. MetS was diagnosed following AHA/NHLBI-2005 criteria. Resistance to thrombolysis was defined as the absence of TCD-assessed complete MCA recanalization 24 hours after tPA infusion. Infarct volume was measured on CT scans. Long-term clinical outcome was evaluated by the modified Rankin scale (mRS) score at day 90. RESULTS: Fifty-eight (58%) patients fulfilled MetS criteria. Median prebolus NIH Stroke Scale score was 17. Forty (42%) patients showed resistance to clot dissolution, and 53 (53%) had poor clinical outcomes (mRS > 2). A multivariable-adjusted logistic regression model identified MetS as independently associated with resistance to thrombolysis (OR 4.7, 95% CI [1.7-13.6], p = 0.004). In the whole sample, MetS was associated with mRS > 2 (OR 2.4 [1.1-5.4], p = 0.03), although this association was no longer significant after multivariable adjustment. However, in patients with atherothrombotic stroke, MetS emerged as an independent predictor of poor long-term outcome (adjusted OR 13.9 [1.3-148.7], p = 0.02). CONCLUSION: In our series, the metabolic syndrome was associated with a poor response to thrombolysis in patients with acute middle cerebral artery occlusions, as reflected by a higher resistance to clot dissolution.