Pilar Chacón

Etiologic Diagnosis of Ischemic Stroke Subtypes With Plasma Biomarkers

Background and Purpose— Because there is no biologic marker offering precise information about stroke etiology, many patients receive a diagnosis of undetermined stroke even after all available diagnostic tests are done, precluding correct treatment. Methods— To examine the diagnostic value of a panel of biochemical markers to differentiate stroke etiologies, consecutive acute stroke patients were prospectively evaluated. Brain computed tomography, ultrasonography, cardiac evaluations, and other tests were done to identify an etiologic diagnosis according to TOAST classification. Blood samples were drawn on Emergency Department arrival (<24 hours) to test selected biomarkers: C-reactive protein, D-dimer, soluble receptor for advanced glycation end products, matrix metalloproteinase-9, S-100b, brain natriuretic peptide (BNP), neurotrophin-3, caspase-3, chimerin, and secretagogin (assayed by ELISA). Results— Of 707 ischemic stroke patients included, 36.6% were cardioembolic, 21.4% atherothrombotic, 18.1% lacunar, and 23.9% of undetermined origin. High levels of BNP, soluble receptor for advanced glycation end products, and D-dimer (P<0.0001) were observed in patients with cardioembolic stroke. Independent predictors (odds ratios with CIs are given) of cardioembolic stroke were as follows: atrial fibrillation 15.3 (8.4–27.7, P<0.001); other embolic cardiopathies 14.7 (4.7–46, P<0.001); total anterior circulation infarction 4 (2.3–6.8, P<0.001); BNP >76 pg/mL 2.3 (1.4–3.7, P=0.001); and D-dimer >0.96 &mgr;g/mL 2.2 (1.4–3.7, P=0.001). Even among patients with transient symptoms (n=155), a high BNP level identified cardioembolic etiology (6.7, 2.4–18.9; P<0.001). A model combining clinical and biochemical data had a sensitivity of 66.5% and a specificity of 91.3% for predicting cardioembolism. Conclusions— Using a combination of biomarkers may be a feasible strategy to improve the diagnosis of cardioembolic stroke in the acute phase, thus rapidly guiding other diagnostic tests and accelerating the start of optimal secondary prevention.

C-Reactive Protein Predicts Further Ischemic Events in First-Ever Transient Ischemic Attack or Stroke Patients With Intracranial Large-Artery Occlusive Disease

Background and Purpose— The role of inflammation in intracranial large-artery occlusive disease is unclear. We sought to investigate the relationship between high-sensitivity C-reactive protein (CRP) levels and the risk of further ischemic events in first-ever transient ischemic attack (TIA) or stroke patients with intracranial large-artery occlusive disease. Methods— Of a total of 127 consecutive first-ever TIA or ischemic stroke patients with intracranial stenoses detected by transcranial Doppler ultrasonography, 71 fulfilled all inclusion criteria, which included angiographic confirmation. Serum high-sensitivity CRP level was determined a minimum of 3 months after the qualifying event. Patients were followed up during 1 year after blood sampling. Results— Thirteen patients (18.3%) with intracranial large-artery occlusive disease experienced an end point event: 9 cerebral ischemic events, 7 of which were attributable to intracranial large-artery occlusive disease, and 4 myocardial infarctions. Patients in the highest quintile of high-sensitivity CRP level had a significantly higher adjusted odds ratio for new events compared with those in the first quintile (odds ratio, 8.66; 95% CI, 1.39 to 53.84; P =0.01). A high-sensitivity CRP level above the receiver operating characteristic curve cutoff value of 1.41 mg/dL emerged as an independent predictor of new end point events (hazard ratio, 7.14; 95% CI, 1.77 to 28.73; P =0.005) and of further intracranial large-artery occlusive disease-related ischemic events (hazard ratio, 30.67; 95% CI, 3.6 to 255.5; P =0.0015), after adjustment for age, sex, and risk factors. Kaplan-Meier curves showed that a significantly lower proportion of patients with a high-sensitivity CRP >1.41 mg/dL remained free of a new ischemic event (P <0.0001). Conclusions— High-sensitivity CRP serum level predicts further intracranial large-artery occlusive disease-related and any major ischemic events in patients with first-ever TIA or stroke with intracranial large-artery occlusive disease. These findings are consistent with the hypothesis that inflammation may be involved in the progression and complication of intracranial large-artery occlusive disease.

Plasmatic level of neuroinflammatory markers predict the extent of diffusion-weighted image lesions in hyperacute stroke.

Sixteen patients with acute middle cerebral artery stroke were studied to correlate neuroinflammatory markers with perfusion- and diffusion-weighted magnetic resonance imaging (MRI) lesion volumes (PWI and DWI). At arrival (less than 6 hours), plasmatic matrix metalloproteinase (MMP)-9, MMP-2, interleukin (IL)-6, IL-8, intercellular adhesion molecule (ICAM)-1, and tumor necrosis factor (TNF)-α were serially measured (by ELISA), and MRI was performed. In cerebral ischemia, tissue destruction seems related to matrix metalloproteinases expression because baseline MMP-9 was the only predictor of the infarct volume measured as a DWI lesion (lineal regression: b = 0.50, 0.25–0.74; P < 0.001). Moreover, the extent of hypoperfused brain area (PWI) was associated with a proinflammatory cytokine release in the next hours (TNF-α and IL-6).

Poststroke C-Reactive Protein Is a Powerful Prognostic Tool Among Candidates for Thrombolysis

Background and Purpose— After acute stroke, an increased level of C-reactive protein (CRP) measured at discharge predicts unfavorable outcome. We sought to investigate whether CRP measured before tissue plasminogen activator (tPA) treatments may add prognostic information to guide stroke thrombolysis. Methods— Our target was 151 consecutive patients with an ischemic stroke involving the middle cerebral artery territory who received tPA within 3 hours of symptom onset. High-sensitivity CRP was measured before tPA administration, and CRP gene polymorphisms were determined (G1059C and C1444T). Functional outcome was evaluated by 3-month modified Rankin Scale (mRS). Results— A total of 143 tPA-treated patients were valid for analyses after exclusion of those with inflammatory diseases and those probably infected (CRP >6 mg/dL). Patients with history of previous stroke, hypertension, or atrial fibrillation had higher levels of CRP (P<0.05). CRP was higher in patients who died after thrombolysis (n=19) than in survivors (0.85 versus 0.53 mg/dL; P=0.002). Among the 94 patients with proximal middle cerebral artery occlusions, CRP level was 0.53 for 81 survivors versus 0.81 mg/dL for 13 who died (P=0.001). CRP-survival association was found even among patients who recanalized by the end of tPA infusion (P=0.007). A correlation between CRP and mRS was found (r=0.36, P=0.02), although CRP polymorphisms were not related to neurological outcome. In a logistic regression model, CRP (odds ratio=8.51; 95% CI, 2.16 to 33.5; P=0.002) and age (odds ratio=6.25; 95% CI, 1.44 to 27.19; P=0.015) were the only baseline mortality predictors. Conclusions— Admission CRP predicts mortality among tPA-treated stroke patients. Very early recanalization does not ameliorate the negative prognostic impact of elevated CRP.

Progression of Symptomatic Intracranial Large Artery Atherosclerosis Is Associated With a Proinflammatory State and Impaired Fibrinolysis

Background and Purpose— The molecular pathways involved in the progression of intracranial large artery atherosclerosis (ILA) are largely unknown. Our objective was to prospectively study the relationship between circulating levels of inflammatory markers and fibrinolysis inhibitors, and the risk of progression of symptomatic ILA. Methods— Seventy-five consecutive patients with first-ever symptomatic intracranial atherostenosis were studied. Blood levels of C-reactive protein (CRP), E-selectin, monocyte chemoattractant protein-1, intercellular adhesion molecule-1, matrix metalloproteinases 1, 2, 3, 8, 9, 10, and 13, plasminogen activator inhibitor-1 (PAI-1), and lipoprotein(a) were measured 3 months after the qualifying stroke or transient ischemic attack. Thereafter, patients underwent long-term transcranial Doppler follow-up to detect progression of ILA. Results— During a median follow-up time of 23 months, 25 (33%) patients showed ILA progression. Multivariable adjusted Cox regression models and Kaplan–Meier curves showed that high baseline level of CRP, E-selectin, intercellular adhesion molecule-1, matrix metalloproteinase 9, PAI-1, and lipoprotein(a) predicted ILA progression independently of vascular risk factors. Of them, only CRP (CRP>5.5 mg/L; HR, 5.4 [2.3 to 12.7]; P=0.0001) and PAI-1 (PAI-1>23.1 ng/mL; HR, 2.4 [1.0 to 5.8]; P=0.05) predicted ILA progression also independently of the other studied molecules. Conclusion— Progression of symptomatic ILA is associated with a proinflammatory state, as reflected by high levels of inflammatory markers, and with defective fibrinolysis, as indicated by raised concentrations of endogenous fibrinolysis inhibitors.

Safety Profile of Tissue Plasminogen Activator Treatment Among Stroke Patients Carrying a Common Polymorphism (C-1562T) in the Promoter Region of the Matrix Metalloproteinase-9 Gene

Background and Purpose— Matrix metalloproteinase-9 (MMP-9) expression, related to blood-brain barrier disruption, has been implicated in the appearance of hemorrhagic transformation (HT) after tissue plasminogen activator (tPA) treatment in stroke patients. Because an in vitro functional polymorphism of the promoter region of MMP-9 gene (C-1562T) has been described, we hypothesize that patients carrying this mutation might have higher MMP-9 levels and greater susceptibility to developing HT when receiving tPA. Methods— We studied strokes involving the middle cerebral artery territory of 61 patients who received tPA <3 hours after stroke onset. Blood samples were obtained before tPA administration. Plasmatic MMP-9 determinations were performed (enzyme-linked immunosorbent assay, ng/mL), and C-1562T genotype was determined by polymerase chain reaction. Healthy age-matched control subjects were used to study allele distribution (n=59). Hemorrhagic events were classified according to CT criteria (petechial hemorrhagic infarctions [HI,1 to 2] and large parenchymal hemorrhages [PH,1 to 2]). Results— Allele distribution was similar in patients and control subjects (CC/CT/TT: 72.3/27.7/0% versus 79.7/20.3/0%, respectively; P =0.37). Among patients, mutation carriers (CT/TT alleles) had similar rates of HT and PH than noncarriers (HT: 23.1% versus 38.2%, P =0.49; PH: 15.4% versus 17.6%, P =1.0). Although the highest MMP-9 level corresponded to patients who later developed a PH (PH, 191.4 ng/mL; non-PH, 68.05 ng/mL; P =0.022), no relation between MMP-9 mutation presence and plasmatic levels was found (CC, 127.12 ng/mL; CT/TT, 46.31 ng/mL; P =0.11). Conclusions— Although MMP-9 level predicts PH appearance after tPA treatment, no relationship exists with the C-1562T polymorphism, probably because this mutation is not functional in response to cerebral ischemia in vivo.

Evidence for the efficacy of statins in animal stroke models: a meta-analysis

J. Neurochem. (2012) 122, 233–243.

Silent myocardial ischemia in patients with symptomatic intracranial atherosclerosis: associated factors.

Background and Purpose— Optimization of coronary risk evaluation in stroke patients has been encouraged. The relationship between symptomatic intracranial atherosclerosis and occult coronary artery disease (CAD) has not been evaluated sufficiently. We aimed to investigate the prevalence of silent myocardial ischemia in patients with symptomatic intracranial atherosclerosis and to identify factors associated with its presence. Methods— From 186 first-ever transient ischemic attack or ischemic stroke patients with intracranial stenoses, 65 fulfilled selection criteria, including angiographic confirmation of a symptomatic atherosclerotic stenosis and absence of known CAD. All patients underwent a maximal-stress myocardial perfusion single-photon emission computed tomography (SPECT). Lipoprotein(a) [Lp(a)], C-reactive protein, and homocysteine (Hcy) levels were determined before SPECT. Results— Stress-rest SPECT detected reversible myocardial perfusion defects in 34 (52%) patients. Vascular risk factors associated with a pathologic SPECT were hypercholesterolemia (P=0.045), presence of >2 risk factors (P=0.004) and high Lp(a) (P=0.023) and Hcy levels (P=0.018). Ninety percent of patients with high Lp(a) and Hcy levels had a positive SPECT. Existence of a stenosed intracranial internal carotid artery (ICA; odds ratio [OR], 7.22, 2.07 to 25.23; P=0.002) and location of the symptomatic stenosis in vertebrobasilar arteries (OR, 4.89, 1.19 to 20.12; P=0.027) were independently associated with silent myocardial ischemia after adjustment by age, sex, and risk factors. Conclusions— More than 50% of the patients with symptomatic intracranial atherosclerosis and not overt CAD show myocardial perfusion defects on stress-rest SPECT. Stenosed intracranial ICA, symptomatic vertebrobasilar stenosis and presence of high Lp(a) and Hcy levels may characterize the patients at a higher risk for occult CAD.

A panel of biomarkers including caspase-3 and D-dimer may differentiate acute stroke from stroke-mimicking conditions in the emergency department.

Abstract.  Montaner J, Mendioroz M, Ribó M, Delgado P, Quintana M, Penalba A, Chacón P, Molina C, Fernández‐Cadenas I, Rosell A, Alvarez‐Sabín J (Universitat Autònoma de Barcelona, Vall d’Hebron Hospital, Barcelona, Spain). A panel of biomarkers including caspase‐3 and d‐dimer may differentiate acute stroke from stroke‐mimicking conditions in the emergency department. J Intern Med 2011; 270: 166–174.

Lipoprotein-associated phospholipase A(2) activity is associated with large-artery atherosclerotic etiology and recurrent stroke in TIA patients.

Background: Lipoprotein-associated phospholipase A2 (Lp-PLA2) has emerged as a novel biomarker in cardiovascular diseases due to its ability to predict stroke in population-based studies. We aimed to investigate Lp-PLA2 levels in transient ischemic attack (TIA) patients and to study their relationship with stroke recurrence. Methods: Lp-PLA2 mass and activity were measured by means of the PLAC test with an automated Olympus analyzer and by a colorimetric activity method (diaDexus) in 166 TIA patients and 144 healthy controls. Vascular risk factors and stroke etiology were assessed. Outcome was defined as the presence of recurrent stroke/TIA within 7 and 30 days after the index TIA. Multivariate analyses were performed to identify potential predictors of recurrence. Results: Both Lp-PLA2 mass and activity (p < 0.05) were higher in TIA than in controls. Several risk factors or previous treatments were associated with Lp-PLA2 mass and activity level. During follow-up, 20 strokes/TIA (12%) occurred within the first 30 days and the presence of a large-artery atherosclerosis etiology of stroke (HR 3.28, p = 0.011), together with the past medical history of hyperlipidemia (HR 3.68, p = 0.008) and Lp-PLA2 activity of >207 nmol/ml/min (HR 2.7, p = 0.042) were all significant predictors for recurrent stroke/TIA. Conclusions: Lp-PLA2 activity might add significant prognostic information in the early evaluation of TIA patients.