Anne Falcou

Prognostic significance of admission levels of troponin I in patients with acute ischaemic stroke

Objectives: Successful prediction of cardiac complications early in the course of acute ischaemic stroke could have an impact on the clinical management. Markers of myocardial injury on admission deserve investigation as potential predictors of poor outcome from stroke. Methods: We prospectively investigated 330 consecutive patients with acute ischaemic stroke admitted to our emergency department based stroke unit. We analysed the association of baseline levels of cardiac troponin I (cTnI) with (a) all-cause mortality over a six month follow up, and (b) inhospital death or major non-fatal cardiac event (angina, myocardial infarction, or heart failure). Results: cTnI levels on admission were normal (lower than 0.10 ng/ml) in 277 patients (83.9%), low positive (0.10–0.39 ng/ml) in 35 (10.6%), and high positive (0.40 ng/ml or higher) in 18 (5.5%). Six month survival decreased significantly across the three groups (p<0.0001, log rank test for trend). On multivariate analysis, cTnI level was an independent predictor of mortality (low positive cTnI, hazard ratio (HR) 2.14; 95% CI 1.13 to 4.05; p = 0.01; and high positive cTnI, HR 2.47; 95% CI 1.22 to 5.02; p = 0.01), together with age and stroke severity. cTnI also predicted a higher risk of the combined endpoint “inhospital death or non-fatal cardiac event”. Neither the adjustment for other potential confounders nor the adjustment for ECG changes and levels of CK-MB and myoglobin on admission altered these results. Conclusions: cTnI positivity on admission is an independent prognostic predictor in acute ischaemic stroke. Whether further evaluation and treatment of cTnI positive patients can reduce cardiac morbidity and mortality should be the focus of future research.

Acute Ischemic Strokes Improving During the First 48 Hours of Onset: Predictability, Outcome, and Possible Mechanisms A Comparison With Early Deteriorating Strokes

BACKGROUND AND PURPOSE Our aims were to identify predictors of early neurological improvement in acute ischemic stroke patients, to evaluate its impact on clinical outcome, and to investigate possible mechanisms. METHODS A consecutive series of 152 first-ever ischemic hemispheric stroke patients hospitalized within 5 hours of onset underwent a first CT scan within 1 hour of hospitalization, and the initial subset of 80 patients also underwent angiography. During the first 48 hours of hospital stay, an increase or a decrease of 1 or more points in the admission Canadian Neurological Scale (CNS) score was defined as early improvement or early deterioration, respectively. Repeated CT scan or autopsy was performed 5 to 9 days after stroke. RESULTS Thirty-four patients (22%) improved, 84 (56%) remained stable, and 34 (22%) deteriorated. Logistic regression, which took into account vascular risk factors, baseline clinical and CT data, and therapies administered, selected younger age, lower admission CNS score, and absence of early hypodensity at first CT as independent predictors of early improvement. Among the patients who underwent angiography, logistic regression selected arterial patency and presence of collateral blood supply as independent predictors of early improvement. At the repeated CT scan or autopsy, improving patients presented the highest frequency of small infarcts. Thirty-day case-fatality rate and disability were lower in improving patients. Variables independently associated with outcome at logistic regression were admission CNS score, early deterioration, and early improvement. CONCLUSIONS Early improvement can be predicted by the absence of early CT hypodensity and is highly predictive of good outcome. Presence of collateral blood supply and presumably early spontaneous recanalization are likely to be the mechanisms underlying early improvement.

Does Sex Influence the Response to Intravenous Thrombolysis in Ischemic Stroke? Answers From Safe Implementation of Treatments in Stroke-International Stroke Thrombolysis Register

Background and Purpose— Women are more likely to have a worse outcome after an acute stroke than men. Some studies have suggested that women also benefit less from intravenous thrombolysis after an acute ischemic stroke, but others found no sex differences in safety and efficacy. We aimed to evaluate differences in 3-month outcome between sexes in intravenous tissue-type plasminogen activator–treated patients registered in the Safe Implementation of Treatments in Stroke-International Stroke Thrombolysis Register. Methods— A total of 45 079 patients treated with intravenous alteplase were recorded from 2002 to 2011. Main outcome measures were symptomatic intracerebral hemorrhage, functional independence (modified Rankin Scale score, 0–2), and mortality at 3 months. Results— Among 25 777 (57.2%) men and 19 302 (42.8%) women, we found no difference in the rate of symptomatic intracerebral hemorrhage (P=0.13), a significantly higher likelihood of functional independence at 3 months in men (P<0.0001) and a higher mortality in women when compared with men (P<0.00001). After adjustment for confounding variables, we did not observe any difference between sexes in functional outcome (odds ratio, 1.03; 95% confidence interval, 0.97–1.09; P=0.39), whereas male sex was related to a higher risk of mortality (odds ratio, 1.19; 95% confidence interval, 1.10–1.29; P=0.00003) and symptomatic intracerebral hemorrhage (odds ratio, 1.25, 95% confidence interval, 1.04–1.51; P=0.02). Conclusions— Data from Safe Implementation of Treatments in Stroke-International Stroke Thrombolysis Register suggest that intravenous thrombolysis may modify the observed survival and recovery advantage for men expected in the natural course of an ischemic stroke, with a possible larger beneficial treatment effect in women when compared with men.

Computed tomography findings in the first few hours of ischemic stroke: implications for the clinician

In order to evaluate the clinical usefulness of emergency computed tomography (CT) in acute ischemic stroke, we assessed whether CT findings within the first few hours of stroke onset reliably predict type, site and size of the index infarction, and risk of death or disability. For this reason we reviewed clinical and CT findings in a cohort of unselected consecutive patients referred to the stroke unit of a large urban hospital because of a presumed ischemic stroke in the anterior circulation (AC), and submitted to CT within 5 h from onset. Out of 158 total patients, emergency CT revealed parenchymal changes compatible with AC focal ischemia in 77 (49%) and a hyperdense middle cerebral artery (MCA) in 41 (26%). Parenchymal changes and hyperdense MCA predicted an AC territorial infarction respectively in 97% of cases (95% C.I. 93% to 100%) and in 95% of cases (95% C.I. 88% to 100%). Site and size of early changes coincided with those of final lesions in 79% of patients with cortical changes and in 95% of patients with cortico-subcortical changes, but only in 37% of patients with initial subcortical changes, the remainder of whom developed a cortico-subcortical infarction. At logistic regression parenchymal changes were the only independent predictor of an AC territorial infarction. Negative predictive power, however, was only 40% (95% C. I. 29% to 51%) for parenchymal changes, and 35% for hyperdense MCA (95% C.I. 26% to 44%). The odds for death or disability at 1 month associated with parenchymal changes were thrice as high as with negative CT, even after adjustment for clinical severity on admission. These results indicate that CT scan adds significantly to the prediction of outcome made on clinical grounds. The frequent development of a territorial infarction in patients with initially negative CT and the subsequent recruitment of the cortex in those initially exhibiting only subcortical changes suggest that the transition from ischemia to infarction often occurs after the first five h following stroke.

Global Survey of the Frequency of Atrial Fibrillation-Associated Stroke: Embolic Stroke of Undetermined Source Global Registry.

Background and Purpose— Atrial fibrillation (AF) is increasingly recognized as the single most important cause of disabling ischemic stroke in the elderly. We undertook an international survey to characterize the frequency of AF-associated stroke, methods of AF detection, and patient features. Methods— Consecutive patients hospitalized for ischemic stroke in 2013 to 2014 were surveyed from 19 stroke research centers in 19 different countries. Data were analyzed by global regions and World Bank income levels. Results— Of 2144 patients with ischemic stroke, 590 (28%; 95% confidence interval, 25.6–29.5) had AF-associated stroke, with highest frequencies in North America (35%) and Europe (33%) and lowest in Latin America (17%). Most had a history of AF before stroke (15%) or newly detected AF on electrocardiography (10%); only 2% of patients with ischemic stroke had unsuspected AF detected by poststroke cardiac rhythm monitoring. The mean age and 30-day mortality rate of patients with AF-associated stroke (75 years; SD, 11.5 years; 10%; 95% confidence interval, 7.6–12.6, respectively) were substantially higher than those of patients without AF (64 years; SD, 15.58 years; 4%; 95% confidence interval, 3.3–5.4; P<0.001 for both comparisons). There was a strong positive correlation between the mean age and the frequency of AF (r=0.76; P=0.0002). Conclusions— This cross-sectional global sample of patients with recent ischemic stroke shows a substantial frequency of AF-associated stroke throughout the world in proportion to the mean age of the stroke population. Most AF is identified by history or electrocardiography; the yield of conventional short-duration cardiac rhythm monitoring is relatively low. Patients with AF-associated stroke were typically elderly (>75 years old) and more often women.

Posterior Circulation Infarcts Simulating Anterior Circulation Stroke: Perspective of the Acute Phase

BACKGROUND AND PURPOSE Ischemic stroke patients whose initial clinical presentation suggests an involvement of the anterior circulation (AC) are sometimes found to have a posterior circulation (PC) infarct, a fact that may generate erroneous decisions in clinical management. We investigated the prevalence of this misdiagnosis in the first few hours after stroke onset. METHODS We performed a cohort study of 158 patients hospitalized within 5 hours of onset of a presumed AC ischemic stroke, as diagnosed on clinical grounds. RESULTS Final CT or pathology diagnosis was AC infarct in 128 patients (81%), a repeatedly negative CT in 14 (9%), PC infarct (5 pons, 1 midbrain and cerebellum, 6 supratentorial territory of the posterior cerebral artery) in 12 (8%), and other or undiagnosed lesions in 4 (3%). AC and PC stroke patients did not differ in terms of age, vascular risk factors, and initial severity, but the latter were more frequently men (83% versus 53%; P = .04), were hospitalized later (mean +/- SD, 168 +/- 86 versus 109 +/- 55 minutes; P = .001), and presented a pure motor hemiparesis or a sensorimotor stroke (50% versus 33%) more often than their counterparts. At baseline CT, PC stroke patients never exhibited an early parenchymal hypodensity in the carotid territory or a hyperdense middle cerebral artery, which were instead found in 59% (P = .0003) and 31% (P = .02) of AC stroke patients, respectively. Early neurological deterioration, 1 month case-fatality rate, and disablement in survivors were comparable in the two groups. CONCLUSIONS Shortly after onset the clinical discrimination between AC and nontypical PC infarcts is not reliable, which explains the frequent occurrence of this misdiagnosis. Emergency CT scan helps in the differential diagnosis only when it demonstrates an early focal hypodensity within the carotid territory.

Which Model of Stroke Unit Is Better for Stroke Patient Management

The increasing prevalence of cerebrovascular diseases has made urgent the need to develop timely and effective treatment strategies to tackle this health problem. Stroke units (SUs) appear to be the ideal setting where the management of acute stroke patients, including specific treatments as thrombolysis, may be optimized. Which model of SU gives the best results is still an unsettled issue. The more intensive and timely multidisciplinary approach to the acute phase of stroke, the management of medical complications, and the earlier and more focused rehabilitation, are likely the most qualifying aspects of our Neurovascular treatment unit.

Pathogenesis, diagnosis and epidemiology of stroke

Stroke is the third leading cause of death, after cardiac disease and cancer, in most industrialised countries. Moreover, stroke is an important cause of long term disability and is the most common life-threatening neurological disease. During past years, there has been a declining trend in stroke incidence, mortality and case-fatality; the reasons for this are unclear and there is no evidence of the persistence of this favourable trend since 1980. The improved knowledge and, consequently, improved management of stroke risk factors and new trends in acute stroke treatment seem to account for this evolution. We present a review of stroke epidemiology, aetiology and emergency clinical and diagnostic aspects, paying particular attention to ischaemic strokes, which have been the subject of most of the research and clinical trials carried out in recent years. Moreover, we propose a brief guideline for diagnosis of stroke in the acute phase.

Treatment of cerebrovascular diseases: state of the art and perspectives.

Summary: Ischaemic penumbra is defined as the area of brain tissue that maintains some blood flow following ischaemic accident. This zone may be rescued by both neuroprotection and arterial revascularization. Early thrombolysis has been used with encouraging results since 1995 in several trials testing both streptokinase and recombinant tissue plasminogen activator (r‐TPA): the r‐TPA results are definitely more positive than those of streptokinase, despite an increased incidence of symptomatic haemorrhagic transformation, r‐TPA significantly reducing death or dependency at the end of follow‐up. Despite the fact that some experimental periods of application of these therapeutic strategies demonstrated real cost‐effective benefits, only 1% of patients reaching hospital in time for thrombolysis are currently treated. This is because the profile of patients at risk of haemorrhagic transformation, which is definitely the most feared side‐effect of thrombolysis in stroke, is yet to be clearly defined. Extended computerized tomography (CT) signs of the index stroke have been repeatedly indicated as reliable predictors of haemorrhagic transformation even if currently there are significant discrepancies in the criteria adopted by different researchers to define early CT signs. Based on experimental ischaemia, strategies for protecting the basal lamina during thrombolysis are suggested: neuroprotection is the second approach to stroke therapy; pharmacological reperfusion and brain protection are probably mutually dependent.

Predictors for Cerebral Edema in Acute Ischemic Stroke Treated With Intravenous Thrombolysis

Background and Purpose— Cerebral edema (CED) is a severe complication of acute ischemic stroke. There is uncertainty regarding the predictors for the development of CED after cerebral infarction. We aimed to determine which baseline clinical and radiological parameters predict development of CED in patients treated with intravenous thrombolysis. Methods— We used an image-based classification of CED with 3 degrees of severity (less severe CED 1 and most severe CED 3) on postintravenous thrombolysis imaging scans. We extracted data from 42 187 patients recorded in the SITS International Register (Safe Implementation of Treatments in Stroke) during 2002 to 2011. We did univariate comparisons of baseline data between patients with or without CED. We used backward logistic regression to select a set of predictors for each CED severity. Results— CED was detected in 9579/42 187 patients (22.7%: 12.5% CED 1, 4.9% CED 2, 5.3% CED 3). In patients with CED versus no CED, the baseline National Institutes of Health Stroke Scale score was higher (17 versus 10; P<0.001), signs of acute infarct was more common (27.9% versus 19.2%; P<0.001), hyperdense artery sign was more common (37.6% versus 14.6%; P<0.001), and blood glucose was higher (6.8 versus 6.4 mmol/L; P<0.001). Baseline National Institutes of Health Stroke Scale, hyperdense artery sign, blood glucose, impaired consciousness, and signs of acute infarct on imaging were independent predictors for all edema types. Conclusions— The most important baseline predictors for early CED are National Institutes of Health Stroke Scale, hyperdense artery sign, higher blood glucose, decreased level of consciousness, and signs of infarct at baseline. The findings can be used to improve selection and monitoring of patients for drug or surgical treatment.