C. Fieschi

Randomised double-blind placebo-controlled trial of thrombolytic therapy with intravenous alteplase in acute ischaemic stroke (ECASS II)

Summary Background Thrombolysis for acute ischaemic stroke has been investigated in several clinical trials, with variable results. We have assessed the safety and efficacy of intravenous thrombolysis with alteplase (0·9 mg/kg bodyweight) within 6 h of stroke onset. Methods This non-angiographic, randomised, double-blind, trial enrolled 800 patients in Europe, Australia, and New Zealand. Computed tomography was used to exclude patients with signs of major infarction. Alteplase (n=409) and placebo (n=391) were randomly assigned with stratification for time since symptom onset (0–3 h or 3–6 h). The primary endpoint was the modified Rankin scale (mRS) at 90 days, dichotomised for favourable (score 0–1) and unfavourable (score 2–6) outcome. Analyses were by intention to treat. Findings 165 (40·3%) alteplase-group patients and 143 (36·6%) placebo-group patients had favourable mRS outcomes (absolute difference 3·7%, p=0·277). In a post-hoc analysis of mRS scores dichotomised for death or dependency, 222 (54·3%) alteplase-group and 180 (46·0%) placebo-group patients had favourable outcomes (score 0–2; absolute difference 8·3%, p=0·024). Treatment differences were similar whether patients were treated within 3 h or 3–6 h. 85 (10·6%) patients died, with no difference between treatment groups at day 90·14 days (43 alteplase, 42 placebo). Symptomatic intracranial haemorrhage occurred in 36 (8·8%) alteplase-group patients and 13 (3·4%) placebo-group patients. Interpretation The results do not confirm a statistical benefit for alteplase. However, we believe the trend towards efficacy should be interpreted in the light of evidence from previous trials. Despite the increased risk of intracranial haemorrhage, thrombolysis with alteplase at a dose of 0·9 mg/kg in selected patients may lead to a clinically relevant improvement in outcome.

Association of outcome with early stroke treatment: pooled analysis of ATLANTIS, ECASS, and NINDS rt-PA stroke trials.

BACKGROUND: Quick administration of intravenous recombinant tissue plasminogen activator (rt-PA) after stroke improved outcomes in previous trials. We aimed to analyse combined data for individual patients to confirm the importance of rapid treatment. METHODS: We pooled common data elements from six randomised placebo-controlled trials of intravenous rt-PA. Using multivariable logistic regression we assessed the relation of the interval from stroke onset to start of treatment (OTT) on favourable 3-month outcome and on the occurrence of clinically relevant parenchymal haemorrhage. FINDINGS: Treatment was started within 360 min of onset of stroke in 2775 patients randomly allocated to rt-PA or placebo. Median age was 68 years, median baseline National Institute of Health Stroke Scale (NIHSS) 11, and median OTT 243 min. Odds of a favourable 3-month outcome increased as OTT decreased (p=0.005). Odds were 2.8 (95% CI 1.8-4.5) for 0-90 min, 1.6 (1.1-2.2) for 91-180 min, 1.4 (1.1-1.9) for 181-270 min, and 1.2 (0.9-1.5) for 271-360 min in favour of the rt-PA group. The hazard ratio for death adjusted for baseline NIHSS was not different from 1.0 for the 0-90, 91-180, and 181-270 min intervals; for 271-360 min it was 1.45 (1.02-2.07). Haemorrhage was seen in 82 (5.9%) rt-PA patients and 15 (1.1%) controls (p<0.0001). Haemorrhage was not associated with OTT but was with rt-PA treatment (p=0.0001) and age (p=0.0002). INTERPRETATION: The sooner that rt-PA is given to stroke patients, the greater the benefit, especially if started within 90 min. Our results suggest a potential benefit beyond 3 h, but this potential might come with some risks.

The European Cooperative Acute Stroke Study (ECASS)

Stroke represents the third most common cause of death and is a major reason for hospitalization in the developed countries. It afflicts approximately 700000 Europeans annually. Stroke is a tragic occurrence to its victims and it also causes enormous financial costs. To date, no therapy is available to improve the outcome of patients with ischemic stroke. Stroke therapies have been aimed at the prevention of future cerebrovascular attacks. The significant mortality and morbidity associated with stroke necessitate development of acute therapeutic interventions to limit stroke mortality and morbidity.

Clinical and instrumental evaluation of patients with ischemic stroke within the first six hours

The development of fibrinolytic agents such as streptokinase and recombinant tissue type plasminogen activator (r-TPA) and other modalities of treatment in acute ischemic stroke, has raised the need for a more precise knowledge of the pathophysiology of the acute phases of ischemic stroke as it pertains to prediction of clinical outcome. In a prospective analysis, 80 patients were studied within less than 6 h from the onset of symptoms by means of a detailed protocol including clinical evaluation, cerebral computed tomography, digital angiography and ultrasound transcranial Doppler sonography. Early angiography revealed a complete arterial occlusion in 76% of cases, the majority of which were intracranial (66%). Seventy percent of the occlusions that were retested were removed within 1 week. Potential embolic sources were found in more than 80% of cases. Patients with documented intracranial occlusion and scarce or absent collateral filling at early angiography, had the worst clinical outcome (P less than 0.05), based on mortality data and the Canadian Neurological Scale. The 30-day mortality rate was 25%. Survival was significantly better (P less than 0.01) in patients with a Canadian Neurological Score on entry of greater than or equal to 6.5 than in patients with a less than 6.5 value. Our data indicate that early pathophysiological studies augment the clinical information and should be taken into account in the design and analysis of therapeutic trials of acute ischemic stroke.

Morphological and Functional Characteristics of Patent Foramen Ovale and Their Embolic Implications

Background and Purpose Transesophageal echocardiography (TEE) has detected a high prevalence of patent foramen ovale (PFO) in stroke patients, but the clinical implications of the distinctive characteristics of this patency are still a matter of debate. Methods We studied 350 patients with acute ischemic stroke or transient ischemic attack (TIA) within 1 week of admission. Of these, 101 (29%) were identified by contrast TEE to have a PFO; 86 patients (25%) were cryptogenic stroke patients, and 163 were excluded because of the presence of a definite or possible arterial or clinical evidence of a source of emboli or small-vessel disease. Thirteen PFO subjects without a history of embolism were designated as the control group. All PFO and cryptogenic stroke patients were followed up by neurological visits. Results Compared with controls, PFO patients with acute stroke or TIA more frequently presented with a right-to-left shunt at rest and a higher membrane mobility (P <0.05). Patients with these characteristics were considered to be at high risk. During a median follow-up period of 31 months (range, 4 to 58 months), 8 PFO and 18 cryptogenic stroke patients experienced recurrent cerebrovascular events. The cumulative estimate of risk of cerebrovascular event recurrence at 3 years was 4.3% (95% confidence interval [CI], 0% to 10.2%) for “low-risk” PFO patients, 12.5% (95% CI, 0% to 26.1%) for “high-risk” PFO patients, and 16.3% (95% CI, 7.2% to 25.4%) for cryptogenic stroke patients (high-risk PFO versus low-risk PFO, P =0.05). Conclusions The association of right-to-left shunting at rest and high membrane mobility, as detected by contrast TEE, seems to identify PFO patients with cerebrovascular ischemic events who are at higher risk for recurrent brain embolism.

Risk factors for clinically diagnosed Alzheimer's disease A case‐control study of an Italian population

We conducted a case-control study of 116 patients with the clinical diagnosis of Alzheimers disease (AD) in seven Italian centers. One hundred sixteen hospital controls and 97 population controls were matched by age, sex, and region of residence to the cases. A structured questionnaire was administered to the next-of-kin of cases and controls by trained interviewers to identify possible risk factors. Genetic, viral, toxic, immunologic, medical, surgical, and personality factors were investigated. Dementia among first- or second-degree relatives and advanced age of the mother at subjects birth (age over 40) were associated with AD. Head trauma was more frequent in cases than in either hospital or population controls, but the differences were not significant. Our data did not confirm the previously reported association with antecedent thyroid disease or family history of Downs syndrome.

The efficacy and safety of enoxaparin versus unfractionated heparin for the prevention of venous thromboembolism after acute ischaemic stroke (PREVAIL Study): an open-label randomised comparison

BACKGROUND Venous thromboembolism prophylaxis with low molecular weight heparin or unfractionated heparin is recommended in acute ischaemic stroke, but which regimen provides optimum treatment is uncertain. We aimed to compare the efficacy and safety of enoxaparin with that of unfractionated heparin for patients with stroke. METHODS 1762 patients with acute ischaemic stroke who were unable to walk unassisted were randomly assigned within 48 h of symptoms to receive either enoxaparin 40 mg subcutaneously once daily or unfractionated heparin 5000 U subcutaneously every 12 h for 10 days (range 6-14). Patients were stratified by National Institutes of Health Stroke Scale (NIHSS) score (severe stroke > or =14, less severe stroke <14). The primary efficacy endpoint was the composite of symptomatic or asymptomatic deep vein thrombosis, symptomatic pulmonary embolism, or fatal pulmonary embolism. Primary safety endpoints were symptomatic intracranial haemorrhage, major extracranial haemorrhage, and all-cause mortality. This study is registered with ClinicalTrials.gov, number NCT00077805. FINDINGS In the efficacy population (ie, one or more dose received, presence of deep vein thrombosis or pulmonary embolism, or assessment for venous thromboembolism), enoxaparin (n=666) and unfractionated heparin (669) were given for 10.5 days (SD 3.2). Enoxaparin reduced the risk of venous thromboembolism by 43% compared with unfractionated heparin (68 [10%] vs 121 [18%]; relative risk 0.57, 95% CI 0.44-0.76, p=0.0001; difference -7.9%, -11.6 to -4.2); this reduction was consistent for patients with an NIHSS score of 14 or more (26 [16%] vs 52 [30%]; p=0.0036) or less than 14 (42 [8%] vs 69 [14%]; p=0.0044). The occurrence of any bleeding was similar with enoxaparin (69 [8%]) or unfractionated heparin (71 [8%]; p=0.83). The frequency of the composite of symptomatic intracranial and major extracranial haemorrhage was small and closely similar between groups (enoxaparin 11 [1%] vs unfractionated heparin 6 [1%]; p=0.23). We noted no difference for symptomatic intracranial haemorrhage between groups (4 [1%] vs 6 [1%], respectively; p=0.55); the rate of major extracranial bleeding was higher with enoxaparin than with unfractionated heparin (7 [1%] vs 0; p=0.015). INTERPRETATION Our results suggest that for patients with acute ischaemic stroke, enoxaparin is preferable to unfractionated heparin for venous thromboembolism prophylaxis in view of its better clinical benefits to risk ratio and convenience of once daily administration.

Comparison of cerebral angiography and transcranial Doppler sonography in acute stroke.

We compared digital intra-arterial angiography and transcranial Doppler sonography in acute cerebral ischemia as part of a wider study on a continuous series of 48 patients with acute focal cerebral ischemia in the carotid territory, observed within 4 hours of the onset of symptoms. The most significant Doppler findings of the middle cerebral artery included no detection of the artery when occlusion of the carotid siphon or the middle cerebral artery at its origin was shown by angiography and reduced flow velocities and asymmetry (symptomatic less than asymptomatic) when the occlusion was located in the terminal tract of the middle cerebral artery mainstem or in numerous terminal branches. Higher flow velocities in the anterior cerebral artery or posterior cerebral artery, mostly in the symptomatic hemisphere, often accompanied middle cerebral artery pathology, probably indicating collateral compensatory pathways.

Derangement of regional cerebral blood flow and of its regulatory mechanisms in acute cerebrovascular lesions

IT HAS LONG BEEN RECOGNIZED~ that cerebral anoxia produces, in addition to damage to nervous structures, a serious derangement of the mechanisms of regulation of cerebral vasomotility. A more detailed knowledge of the functional aspects of cerebral vascular pathology has been permitted by the availability of reliable methods of exploring quantitatively the circulation in discrete parts of the brain. Studies performed in patients with the radioactive inert gas regional clearance method proposed by Lassen and co-workers in 1963* have demonstrated that [ 11 the autoregulation (constancy of cerebral blood flow at different levels of perfusion pressure) is lost in many patients in the first days after an ischemic insult,”-5 [2] in the same group of patients6 the response to changes in arterial CO, tension may be regionally impaired (loss or delay of cerebral vasodilatation in response to hypercapnia had been previously demonstrated with the N 2 0 method7 and with radioalbumins), and [3] shortly after an acute brain infarction a cerebral reactive hyperemia with marked increase in blood flow (the “luxury perfusion” phenomenon) may occur.5~9,10 Experimental studies have confirmed the above observations,l1-15 whose physiological and possibly practical implications are of considerable importance. The present study further documents the

Early collateral blood supply and late parenchymal brain damage in patients with middle cerebral artery occlusion.

We angiographically studied 80 patients within 6 hours after the onset of ischemic supratentorial infarction. From this group we selected 36 patients with middle cerebral artery occlusion who survived. In these 36 patients, we compared the presence of a collateral blood supply during the early phase with the extent of final parenchymal brain damage obtained by computed tomography 3 months after the event. The presence of a collateral circulation during the first few hours after the stroke reduced the size of the final parenchymal brain damage in patients with middle cerebral artery stem-trunk occlusion. The collateral blood supply was more efficient in patients who had no significant stenosing lesions of the extracranial internal carotid artery. Our data confirm that the lenticulostriate arteries are end arteries not supplied by collateral blood vessels and suggest that lesions formerly thought to be caused by hemodynamic mechanisms (watershed infarcts) or arteriolar lesions (lacunar infarcts) may be due to middle cerebral artery occlusions.