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Biomedical subjects

M Verstraete

Publications and source records attributed to M Verstraete.

At least 73 records · Page 4Linked to original sources
PubMed1991

Risk factors, interventions and therapeutic agents in the prevention of atherosclerosis-related ischaemic diseases.

Of the major risk factors for atherosclerosis, high factor VII and fibrinogen levels, genetic predisposition, gender and age cannot be influenced. Reduction of high blood pressure reduces the cerebral but not the coronary vascular risk and correction of dyslipidaemia correlates with cardiovascular risk. Other major risk factors (tobacco consumption, obesity, sedentary lifestyle and diabetes) can also be modified. Aspirin in doses of approximately 300 mg/day may be recommended for the primary prevention of myocardial infarction (MI), but only in those patients with a moderate to high risk of cardiovascular disease. Aspirin reduces the risk of fatal and nonfatal MI by about 50% and also decreases the overall mortality rate among patients with unstable angina. A lower dose of aspirin (150 mg/day) also reduces mortality by 23% in the acute phase of MI. In doses of 300 mg/day, aspirin is useful in the secondary prevention of MI and reduces the overall mortality rate by 15%. Various antiplatelet agents, including aspirin (alone or combined with dipyridamole) and ticlopidine, have proved useful in the prevention of thrombosis in aorto-coronary grafts, provided treatment begins at the latest 6 hours after surgery. The usefulness of antiplatelet drugs has been well established in the prevention of immediate reocclusion following coronary angioplasty, but not in the prevention of late reocclusion. Aspirin and ticlopidine are also beneficial in extracorporeal circulation techniques. In patients with a synthetic cardiac valve prosthesis, antivitamin K-anticoagulants are still indispensable lifelong, but their antithrombotic effect can be reinforced by dipyridamole or aspirin. Diuretics probably provide the best primary protection against cerebrovascular accidents, although medium doses of aspirin may be considered in elderly people at high risk of such accidents. Aspirin (alone or combined with dipyridamole) and ticlopidine may be recommended for the secondary prevention of cerebral ischaemic accidents. Aspirin (with or without dipyridamole) and ticlopidine reinforce the treatment of obliterative arterial disease in the lower limbs.

Aspirin↗
PubMed1991

Unresolved issues in the thrombolytic treatment of myocardial infarction.

Despite enormous advances made in understanding of the biochemistry of fibrinolytic agents and their extensive clinical use in acute myocardial infarction a number of unresolved issues remain. There is an intriguing divergence of left ventricular response and reduction of mortality in patients with acute myocardial infarction treated with thrombolytic drugs. It is also difficult to explain why patients treated late have a reduced mortality after thrombolytic treatment. Uncertainty prevails on the validity of thrombolysis in patients with a low and very high risk of mortality. Resistance of coronary occlusion to any thrombolytic is another unexplained fact. Alteplase and saruplase are more fibrin-specific thrombolytic drugs than anistreplase. These and the thrombolytic drugs of the first generation (streptokinase and urokinase) have shortcomings and limitations. It is being explored whether prolonged intravenous maintenance infusions are more effective if replaced by a bolus injection, accelerated infusion or the combined intravenous administration of thrombolytic agents.

Age Factors↗
PubMed1991

[Psychogenic hemorrhages].

Psychogenic "purpura" consists in the spontaneous appearance of recurrent bruising, it is a reality which is still unexplained. Most often woman with an underlying emotional disorder are affected. In addition to cutaneous ecchymoses and hematomas they may have menometrorrhagia, hematuria, epistaxis and gastrointestinal bleeding in addition to many other complaints encompassing multiple organ systems. Cutaneous bruising is heralded by a burning or stinging sensation followed after a few hours by local warmth, puffiness and erythema, most often with some itching. The pain subsides when the ecchymoses appear a day later or earlier. Blood coagulation and hemostatic tests remain normal in all patients. A rare but poorly studied variety of psychogenic bleeding are religious or other stigmata with periodic bleeding at hands and feet, under the left breast and at the forehead, occasionally with bloody tears. It would be risky to substitute one poorly understood diagnosis (stigmata) with another (hysterical conversion). It is very difficult to distinguish spontaneous psychogenic from selfinflicted iatrogenic bleeding (purpura factitia) because patients may have the same obsessive-compulsive behavior or hysterical trait. Moreover, patients with self-induced bleeding act in a most clever manner and their continuous observation is difficult. The differential diagnosis with the "battered child" syndrome is rather easy. Other bleeding disorders with normal coagulation tests are an inherited failure of the collagen biosynthesis (f.i. Ehlers-Danlos syndrome) or congenital or acquired vascular disorders (purpura senilis of Bateman, vitamin C deficiency, morbus Schamberg, purpura annularis of Majocchi, orthostatic purpura). There is virtually no scientific information on the interaction between the nervous system and hemostasis or blood coagulation. The only therapeutic approach in patients with psychogenic bleeding is psychiatric with particular attention to the sociocultural background of the patient and his family.

Child↗
PubMed1990

Usefulness of high-frequency analysis of signal-averaged surface electrocardiograms in acute myocardial infarction before and after coronary thrombolysis for assessing coronary reperfusion.

The incidence of late potentials on the signal-averaged electrocardiogram before and after coronary thrombolysis was studied in 54 patients with an acute myocardial infarction of less than or equal to 5 hours' duration and with an angiographically documented total occlusion of the infarct-related coronary artery on admission. A significant (p = 0.038) 50% relative reduction in the incidence of late potentials was observed in the group of 35 patients who underwent reperfusion: from 16 of 35 (46%) before to 8 of 35 (23%) at 120 minutes after the start of thrombolytic treatment. No significant reduction was seen in the 19 patients in whom thrombolysis was unsuccessful: from 8 of 19 (42%) before to 7 of 19 (37%) afterward. Despite successful recanalization, late potentials persisted or newly developed after thrombolytic therapy in 8 of 54 patients (15%). It is concluded that successful thrombolysis reduces the incidence of late potentials on the signal-averaged electrocardiogram but that the sensitivity and specificity of this finding are not high enough to allow reliable monitoring of coronary reperfusion at the bedside.

Arrhythmias, Cardiac↗
PubMed1990

Fast Multiplex polymerase chain reaction on boiled clinical samples for rapid viral diagnosis.

An assessment of optimal conditions for rapid simultaneous amplification of multiple human papillomavirus (HPV) sequences has been made using Thermus aquaticus DNA polymerase. All variables of practical value were studied by amplifying known target-sequences from ten-fold dilutions of well characterized cell lines. In our hands, Fast Multiplex PCR (FM-PCR), the technique of running multiple PCR reactions simultaneously with minimum incubation time at each temperature, was highly sensitive (amplification factor = 5 x 10(9) after 50 cycles), specific (100%) and reproducible (100%) for several microbiological applications. Diagnosis was generally obtained in less than 5 h after sampling. The results show that, after optimization of assay conditions, efficiency and specificity of Multiplex PCR depends exclusively on the primers design and concentration of the primers.

Base Sequence↗
PubMed1990

Angiographic assessment of the infarct-related residual coronary stenosis after spontaneous or therapeutic thrombolysis.

The severity of the infarct-related residual coronary stenosis after spontaneous or therapeutic thrombolysis was quantitatively assessed in 91 patients with an acute myocardial infarction who were allocated to treatment in the acute stage with either a thrombolytic agent (100 mg of recombinant tissue-type plasminogen activator given over 3 h, 49 patients) or a placebo (42 patients). Heparin and aspirin were given to both groups until angiography was performed. Digital subtracted images of the infarct-related coronary vessel were obtained 10 to 14 days after hospital admission and were subsequently analyzed with the use of a computer-assisted coronary stenosis measurement system. Neither treatment group differed significantly in age, gender or location of the culprit coronary lesion. Median values (90% range) in the thrombolysis and control groups were, respectively, 1.95 (0.9 to 5.3) mm versus 1.7 (0.9 to 3.4) mm for stenosis length; 1.4 (0.8 to 2.7) mm versus 1.4 (0.9 to 1.8) mm for minimal luminal diameter; 57% (36% to 75%) versus 58% (44% to 71%) for diameter obstruction; 82% (59% to 95%) versus 82% (68% to 92%) for geometric area obstruction; and 78% (58% to 91%) versus 79% (66% to 90%) for densitometric area obstruction. The difference between the two groups was not statistically significant for any of these measurements. Thus, in this study no significant differences in anatomy or severity of residual coronary stenosis could be demonstrated at 10 to 14 days after an acute myocardial infarction in patients with a recanalized infarct-related vessel, whether or not thrombolytic therapy was given on admission. These results indicate that with effective antithrombotic treatment, gradual endogenous fibrinolysis or more rapid lysis induced by the infusion of a thrombolytic agent results in a similar infarct-related coronary lesion at the time of hospital discharge.

Angiography, Digital Subtraction↗
PubMed1990

Evaluation of the effect of thrombolytic treatment on infarct size and left ventricular function by enzymatic, scintigraphic, and angiographic methods. The European Cooperative Study Group for Recombinant Tissue Type Plasminogen Activator.

In a double-blind trial of the European Cooperative Study Group, 721 patients with acute myocardial infarction of less than 5 hours' duration were given either 100 mg recombinant tissue-type plasminogen activator (rt-PA) intravenously over 3 hours or an equivalent placebo infusion. In a subset of 312 patients, infarct size was assessed by the cumulative myocardial release of alpha-hydroxybutyrate dehydrogenase (HBDH) during the first 72 hours and by planar thallium scintigraphy (index of hypoperfusion) performed 10 to 22 days after the acute event. Left ventricular ejection fraction (LVEF) was determined by contrast and nuclear angiography. The median values of HBDH during the first 72 hours were 20% lower and the median values of thallium-201 28% smaller in the rt-PA group in comparison with controls. A significant but limited improvement of angiographic LVEF (2 absolute percentage points) was also shown in the patients treated with rt-PA. A moderate but statistically significant linear association between both measurements of infarct size and LVEF was found.

Adult↗
PubMed1990

Heparin and thrombosis: a seventy year long story.

Heparin was a chance discovery made by a medical student who was searching for a clot-promoting activity in various tissue extracts and found an inhibitor of coagulation. It has taken 20 years from the discovery of heparin in 1916 to its therapeutic use (1937). This long delay was mainly due to problems with the purification and extraction on large scale of the active material. Standard unfractionated heparin is a mixture of mucopolysaccharide chains of various length that may range from 5,000 to 30,000 daltons. Heparin is only effective as an anticoagulant in the presence of a plasma protein, termed antithrombin III, with which it forms a complex. High- and low-affinity heparin are two types that readily bind or do not bind to antithrombin III. The pharmacokinetics of unfractionated heparin are compatible with a model based on the combination of a saturable and a linear mechanism. Low-molecular-weight heparins have been produced by a variety of techniques, and their molecular weights range from 3,000 to 9,000 daltons. These preparations have a ratio of anti-Xa activity to anti-II activity of approximately 4, while it is 1 for unfractionated heparin. After intravenous administration of low-molecular-weight heparins, the half-life of the antifactor Xa activity is considerably longer than for unfractionated heparin, while the anti-factor II half-lives are similar. In contrast to unfractionated heparin, low-molecular-weight heparin is virtually completely absorbed after subcutaneous administration, and its biological half-life is almost twice as long.(ABSTRACT TRUNCATED AT 250 WORDS)

Heparin↗
PubMed1990

Significance of initial ST segment elevation and depression for the management of thrombolytic therapy in acute myocardial infarction. European Cooperative Study Group for Recombinant Tissue-Type Plasminogen Activator.

To determine the ability of initial ST segment elevation and depression to predict infarct size limitation by thrombolytic therapy, data were analyzed in 721 patients with acute myocardial infarction who were admitted to a randomized, placebo-controlled study of intravenous recombinant tissue-type plasminogen activator. Patients with QRS duration of 120 msec or more or with previous history of myocardial infarction were excluded, leaving 322 in the treatment and 333 in the placebo group. Cumulative 72-hour release of alpha-hydroxybutyrate dehydrogenase and global ejection fraction as well as left ventricular wall motion derived from angiography were used as independent measures of infarct size. Electrocardiograms obtained at admission, 6 hours after start of therapy, and before discharge were analyzed. All ST measurements were made by hand at the J point and 60 msec after the J point. Patients with high ST segment elevation at admission (i.e., sum of ST elevation at 60 msec after the J point was 20 mm or more) had significantly larger infarction and higher hospital mortality when compared with those with lower (less than 20 mm) ST elevation. Reciprocal ST segment depression also showed a linear relation with infarct size and mortality, independent from ST elevation, both in anterior and inferior myocardial infarction. The sum of deviations measured at the J point and 60 msec after the J point differed significantly, especially in anterior myocardial infarction at admission (mean, 16 +/- 9 versus 23 +/- 11 mm). The prognostic value of one measurement was not, however, superior over the other. Treatment with recombinant tissue-type plasminogen activator was most effective in those with large ST deviations at admission, but patients with anterior infarction and smaller ST shifts also appeared to benefit from therapy. Results in individual patients were variable, and the overall correlation of initial ST shifts with enzymatic infarct size was rather low. In conclusion, the present study shows that the magnitude of initial ST elevation and also of reciprocal ST depression in the admission electrocardiogram is valuable for the management and assessment of thrombolytic therapy in patients with acute myocardial infarction.

Double-Blind Method↗
PubMed1990

Pharmacotherapeutic aspects of unfractionated and low molecular weight heparins.

Standard unfractionated heparin is a mixture of mucopolysaccharide chains of various length that may vary from 5000 to 30,000 daltons. Heparin is only effective as an anticoagulant in the presence of a plasma protein termed antithrombin III, with which it forms a complex. High- and low-affinity heparin are 2 types that readily bind or do not bind, respectively, to antithrombin III. The pharmacokinetics of unfractionated heparin are compatible with a model based on the combination of a saturable and a linear mechanism. The primary indication for intravenous infusion of conventional heparin is to prevent extension of an established arterial, venous or intracardiac thrombus. The average requirement is 400 U/kg/24h. Subcutaneous administration of 5000U of concentrated unfractionated heparin, administered every 8 or 12 hours, is effective and safe in the prevention of postoperative venous thrombosis and pulmonary embolism in patients at medium thrombotic risk. Adequate prophylaxis is also obtained in patients at high thrombotic risk if 5000U of heparin combined with 0.5mg dihydroergotamine is given subcutaneously 3 times daily, or by monitoring the 3 subcutaneous doses of heparin in order to maintain an adjusted activated partial thromboplastin time (APTT) of around 50 to 70 seconds. Low molecular weight heparins have been produced by a variety of techniques and their molecular weights range from 3000 to 9000 daltons. These preparations have a ratio of anti-factor Xa activity to anti-factor IIa activity of about 4, while the ratio for unfractionated heparin is 1. After intravenous administration of low molecular weight heparin, the half-life of the anti-factor Xa activity is considerably longer than for unfractionated heparin, while the anti-factor IIa half-lives are similar. In contrast to unfractionated heparin, low molecular weight heparin is completely absorbed after subcutaneous administration and its biological half-life is almost twice as long. In spite of certain differences with regard to the ratio between factor Xa and IIa inhibition, the various low molecular weight preparations show a rather similar absorption pattern. The bioavailability of all low molecular weight heparin fractions is substantially higher than that of unfractionated heparin, which renders their use more simple. Low molecular weight heparins less readily enhance platelet aggregation although there is no evidence that low molecular weight heparins are less antigenic or that they do not interact with platelet IgGFc receptor. A lower bleeding incidence for equivalent antithrombotic efficacy of fractionated heparins when compared to unfractionated heparins has yet to be established in humans.(ABSTRACT TRUNCATED AT 400 WORDS)

Heparin↗
PubMed1990

Thrombolytic treatment in acute myocardial infarction.

All thrombolytic agents convert plasminogen to plasmin, either directly, as in the case of urokinase, saruplase, and alteplase, or indirectly, as in the case of streptokinase. In the majority of recent clinical trials with streptokinase, a high-dose (0.7-1.5 million units), brief-duration (30-90 minutes) drug regimen has been used. After a mean interval of 4.2 hours from onset of chest pain to intravenous infusion of streptokinase, repeat angiography performed 60-90 minutes after the start of thrombolytic treatment gave a reperfusion rate of 43%; the corresponding figures for anistreplase, saruplase, and alteplase are 56%, 67%, and 69%. The patency rates obtained in similar studies with the same end point are 56% for streptokinase, 77% for anistreplase, 62% for urokinase, 71% for saruplase, and 75% for alteplase. The in-hospital mortality in randomized trials (six large studies in a total of 31,713 randomized patients) with intravenous high-dose streptokinase decreased from 12.0% in the control group to 9.47% in the streptokinase group. In a mortality study involving 1,258 patients randomized to intravenous anistreplase or placebo, the 30-day mortality was reduced by 47%, from 12.2% to 6.4%. In a large trial in which 5,011 patients were randomized to alteplase or placebo, the 30-day mortality was 7.2% compared with 9.8% in controls, a reduction of 27% by alteplase. In another trial, 721 patients were randomized to placebo or alteplase; all patients received acetylsalicylic acid and intravenous heparin. The 14-day mortality was only 2.8% in the alteplase group, 51% less than that in the control group. It is most important that the favorable impact on hospital survival be maintained at 1 year for any thrombolytic drug. Large-scale trials directly comparing mortality after alteplase, streptokinase, or anistreplase are being performed or are in the planning phase. The risk of bleeding exists with any thrombolytic agent; intracranial bleeding is the most serious risk. In a large trial in 5,011 patients with acute myocardial infarction, stroke occurred in 1.1% of alteplase-treated patients compared with 1.0% in placebo-treated controls. Haunting problems are residual stenosis of the coronary artery and reocclusion. Urgent angioplasty does not seem to be the right answer; more effective antithrombotic strategies have yet to be developed.

Coronary Vessels↗
PubMed1990

Coronary atherosclerosis and thrombosis.

The relationship of thrombus to atherosclerosis is complex and far more wide-reaching than the obvious causal association of a thrombotic occlusion in a coronary artery with myocardial infarction. An atherosclerotic plaque may be eccentric (localized primarily along one segment of the arterial wall) or concentric (localized circumferentially) and is a complex structure composed of connective tissue, calcium, inflammatory cells and lipid in proportions differing from plaque to plaque. The consistency of plaques depends on the proportion of their component elements: a heavily fibrotic and calcified plaque is hard, whereas a plaque composed predominantly of cholesterol-ester and lipid-containing macrophages is soft. Plaques with a soft lipid core may be covered by a relatively thin cap of fibrous connective tissue separating the plaque material from the luminal blood flow. A rupture or fissure of this cap allows blood to enter the plaque causing dissection of its structure and deposition of fibrin in the plaque. Fissuring commonly promotes thrombosis also in the lumen of the artery and may be followed by thrombus fragmentation and embolization. Mural thrombi may wax and wane, causing intermittent occlusions and fleeting, minor clinical symptoms. Further episodes of thrombosis increase the mass of the mural thrombus in the already restricted lumen and may herald the onset of ischemic symptoms, abruptly aggravate a stable clinical state and produce the crescendo type of unstable angina, dysrhythmias, myocardial infarction or sudden coronary death. The episodic dynamic progress of atherosclerotic disease and local thrombosis governs the episodic evolution of the clinical course.

Coronary Artery Disease↗
PubMed1990

[Thrombolytic therapy in acute myocardial infarct].

All thrombolytic agents convert plasminogen to plasmin, either directly as urokinase, saruplase and alteplase or indirectly as streptokinase. In the majority of recent clinical trials with streptokinase, a high-dose (0.7 to 1.5 mega-units), brief-duration (30 to 90 minutes) drug regimen has been used. After a mean time interval of 4.2 hours from onset of pain to intravenous infusion of streptokinase, a repeat angiography performed 60 to 90 min after start of thrombolytic treatment gives a reperfusion rate of 43%, the corresponding figures for anistreplase, saruplase and alteplase are 56%, 67% and 69%. The patency rates of similar studies with the same endpoint are for streptokinase 56%, for anistreplase 77%, for urokinase 62%, for saruplase 71% and for alteplase 75%. The reduction in hospital mortality in randomized trials with intravenous streptokinase (high-dose) is in 6 large studies in a total of 23,267 randomized patients from 10.7% in the control group to 7.0% in the streptokinase group. In a mortality study involving 1,004 patients randomized to intravenous anistreplase or placebo the 30-day mortality was reduced by 47%, from 12.2% to 6.4%. A large trial in which 5,011 patients were randomized to alteplase or placebo, the 30-day mortality was 7.2% compared to 9.8% in controls, a reduction of 27% by alteplase. In another trial 721 patients were randomized to placebo or alteplase; all patients were on aspirin. The 14-day mortality was only 2.8%, 51% less than that in the control group. It is most important that the favourable impact on hospital survival is maintained at 1 year with any thrombolytic drug. Large scale trials directly comparing mortality after alteplase, streptokinase or anistreplase are being performed or in the planning phase. The risk of bleeding exists with any thrombolytic agent but intracranial bleeding is the most serious one. In a large trial on 5,011 patients with acute myocardial infarction, stroke occurred in 1.1% of alteplase treated patients compared with 1.0% in placebo treated controls. Crucial problems are residual stenosis of the coronary artery and reocclusion. Urgent angioplasty does not seem to be the right answer; more effective antithrombotic strategies still have to be developed.

Coronary Thrombosis↗
PubMed1989

Bolus alteplase.

Explore the source record for details and available documents.

Clinical Trials as Topic↗
PubMed1989

Increased serum levels of fibrinogen degradation products due to treatment with recombinant tissue-type plasminogen activator for acute myocardial infarction are related to bleeding complications, but not to coronary patency. European Co-operative Study Groups for rt-PA.

The association of increasing serum levels of fibrinogen degradation products after recombinant tissue-type plasminogen activator (rt-PA) therapy with bleeding and early coronary patency was assessed in 242 patients with acute myocardial infarction. After administration of 5,000 IU heparin, a median of 40 mg (range 35 to 60) of double chain rt-PA was given intravenously in 90 min. Bleeding occurred in 62 patients; in 73% of patients it was observed within the 1st 24 h and 84% of events consisted of hematoma or prolonged bleeding, or both, at puncture sites. Bleeding events occurred 2.12 times as often in patients with serum levels of fibrinogen degradation products greater than 85 mg/liter as in patients with serum levels less than 22 mg/liter (95% confidence interval 1.01 to 4.43). The infarct-related coronary vessel was patent in 65% of patients at 90 min after the start of rt-PA infusion. In patients with high serum levels of fibrin(ogen) degradation products, coronary patency at 90 min after the start of rt-PA infusion was not better (13% less, 95% confidence interval - 33%, 13%) than in patients with low serum levels. This uncoupling of thrombolytic effect in terms of coronary patency and systemic fibrinogenolysis confirms the experimentally demonstrated fibrin specificity of double chain rt-PA in human subjects. Because fibrin specificity of single chain rt-PA is at least similar to that of double chain rt-PA, the observations in this analysis most likely hold also for single chain rt-PA.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1989

Use of thrombolytic drugs in non-coronary disorders.

Clinical experience with thrombolytics in non-coronary disorders is limited to the plasminogen activators streptokinase, urokinase and alteplase; therapeutic trials with anistreplase (APSAC) are almost, and with saruplase completely, limited to acute myocardial infarction. In terms of thrombus clearance, thrombolytic drugs are superior to heparin in patients with recent deep vein thrombosis in the pelvis or lower limbs. In aggregate, thrombi younger than 8 days are lysed in approximately 60% of patients treated with streptokinase, urokinase or alteplase. The results of studies assessing the subsequent development of the postphlebitic syndrome are conflicting, but most suggest that thrombolytic therapy can reduce symptoms of chronic venous insufficiency. Currently, the combination of systemic thrombolytic drugs followed by heparin is recommended for patients with acute major pulmonary embolism who are haemodynamically unstable. Streptokinase, urokinase and alteplase have all been shown to accelerate the lysis of pulmonary emboli and to decrease pulmonary vascular obstruction and pulmonary hypertension. Systemic venous or intrapulmonary infusions of alteplase offers the same benefit in terms of angiographic and haemodynamic improvement. A short infusion of 100 mg alteplase over 2 hours seems to be superior to a 24-hour infusion of urokinase. None of the thrombolytic trials in pulmonary embolism have been large enough to demonstrate a reduction in mortality. It is now generally accepted that, unless contraindicated, thrombolytic therapy is the front-line treatment for patients with massive pulmonary embolism and major haemodynamic disturbance. The local treatment of acute arterial occlusion in limb arteries results in rapid clearing of the artery in 67% of patients treated with streptokinase; the corresponding success rates for urokinase and alteplase are 81% and 88 to 94%, respectively. The main question appears to be the identification of patients in whom local thrombolysis is the treatment of choice, as opposed to established therapeutic modalities. Thrombolytic treatment following a major ischaemic stroke is hazardous, although clinical improvement has been noted in a minority of patients with recanalised cerebral arteries. The safety and efficacy of thrombolytic treatment remains unproven for this indication, and its use must be restricted to experimental protocols. Thrombolytic treatment in retinal artery or vein occlusion has, in practice, been abandoned.

Fibrinolytic Agents↗