Occlusive cerebrovascular disease

One year follow-up of patients clinically preselected for excessive risk of stroke

From a consecutive series of 812 patients at risk of stroke we selected 100 who seemed to be at high risk (excessive stroke risk--ESR) on the following clinical criteria: either multiple reversible ischemic attacks in one carotid territory or multiple (or bilateral) severe stenotic carotid lesions. The patients of the first subgroup received medical therapy and those of the second were referred for surgery. The 100 patients were followed up for 12 months, during which 29 patients had cerebral ischemic events: 17 having stroke and 12 TIA. This study suggests that it is possible to identify beforehand subgroups of ESR patients, thereby facilitating the selection of patients for brain protection and avoiding huge trials of unselected cerebrovascular patients.

Italian multicenter study of reversible cerebral ischemic attacks. Part 5. Risk factors and cerebral atherosclerosis

As part of a prospective study, the influence of several premorbid and environmental factors on the presence, extent and severity of cerebral vessel atherosclerosis was studied in 462 patients with clinical diagnosis of RIA who underwent cerebral angiography. The extent and severity of atherosclerosis of the cerebral vessels was quantified using extracranial and intracranial cerebrovascular scores (ECS, ICS) based on the number and severity of the lesions in 11 extracranial and 21 intracranial arterial segments. Results of univariate and multivariate analyses indicate that the presence of atherosclerotic changes of cerebral vessels, as shown by angiography, was strongly related with age in both sexes. The lesions were more frequent in males, in particular under age 55. Elevated cholesterol was associated with a higher incidence of atherosclerotic lesions. Smoking was associated with a higher incidence of extracranial lesions. Age, smoking and history of hypertension were the best predictors of the extent and severity of cerebral vessel atherosclerosis.

Italian multicenter study on reversible cerebral ischemic attacks: VI--Prognostic factors and follow-up results

A total of 462 patients (mean age 52 years) affected by reversible focal ischemic attacks (RIAs) were followed prospectively in 8 neurologic institutions in Italy for 4 years. All cases were evaluated with a cerebral angiography and 21% of angiograms were normal. At the end of the follow-up period the cumulated probability for death, stroke, cardiac event and new RIA was respectively 7%, 8%, 3% and 36%. The predictive value of the baseline characteristics of this series was evaluated by a multifactorial analysis which showed that RIA and stroke (specific cerebrovascular risk) were more likely to develop in patients with a history of more than one RIA and in those in whom multiple vascular territories were involved. Moreover, previous myocardial infarction, intermittent claudication, angina pectoris, time elapsed since the first attack, and duration and severity of the attack itself were independently associated with general cardiovascular risk (death, stroke and myocardial infarction). We conclude that predictive factors, and thus also pathogenetic mechanisms, may be different for general cardiovascular risk and specific cerebrovascular risk in RIA patients.

Role of antiplatelet agents in cerebrovascular disease

It is now generally accepted by neurologists that most transient ischaemic attacks, particularly in the carotid artery territory, have a thromboembolic basis. These emboli are, for the most part, fibrin-platelet aggregates. Others which contain atheromatous debris are more likely to produce longer lasting neurological deficits. If one assumes this hypothesis then it is reasonable to employ drugs which interfere with platelet aggregation in order to prevent cerebrovascular symptoms and signs. Acetylsalicylic acid (aspirin) prevents aggregation by inhibiting the 'release reaction' initiated by thromboxane A2. This inhibition lasts for the life of the affected platelets. Recent trials in the United States and Canada have demonstrated a positive clinical benefit from the employment of aspirin in patients suffering from transient cerebral ischaemic attacks and amaurosis fugax. There was a reduction or cessation of the attacks in both males and females and a 50% reduction of stroke morbidity and mortality in males.

XIV. Cerebral ischemia: the role of thrombosis and of antithrombotic therapy. Study group on antithrombotic therapy

A revival of interest in antithrombotic agents for the treatment of ischemic cerebrovascular disease has resulted in the widespread use of oral anticoagulants for the prophylaxis and therapy of the ischemic variety of stroke, and has generated enthusiasm for the use of platelet-suppressant agents such as aspirin, dipyridamole, and sulfinpyrazone. In delineating the several clinical types of focal ischemic disease and outlining the causes of cerebral ischemia and infarction, the study group considers the problems of data interpretation in the face of inconsistent terminology. The basic mechanisms of hemostasis and thrombogenesis are concisely detailed. Finally, the study group critically reviews extensive earlier reports of clinical trials of anticoagulants, platelet function suppressants, and thrombolytic agents, and reassesses according to present-day statistical standards the significance of the results. The information contained in this report should familiarize the reader with sufficient data to permit him to utilize antithrombotic agents under a variety of circumstances and to appreciate the contraindications and potential dangers in their use.