Hemorrhagic complications of long-term anticoagulant therapy for ischemic cerebral vascular disease

Small bowel intramural hematoma caused by warfarin: case report and literature review

BACKGROUND

Intramural hematoma of the small bowel is a rare yet acute gastrointestinal condition typically linked with impaired coagulation function, often posing diagnostic challenges. It is principally encountered in patients undergoing prolonged anticoagulant therapy, specifically warfarin.

CASE PRESENTATION

We reported a case of intramural hematoma associated with warfarin use. The patient was admitted to hospital with abdominal pain and had received anticoagulant therapy with warfarin 2.5 mg/day for 4 years. Laboratory examination showed decreased coagulation function, abdominal CT showed obvious thickening and swelling of part of the jejunal wall, and abdominal puncture found no gastroenteric fluid or purulent fluid. We treated the patient with vitamin K and fresh frozen plasma. The patient was discharged after the recovery of coagulation function. Then we undertaook a comprehensive review of relevant case reports to extract shared clinical features and effective therapeutic strategies.

CONCLUSION

Our analysis highlights that hematoma in the small intestinal wall caused by warfarin overdose often presents as sudden and intense abdominal pain, laboratory tests suggest reduced coagulation capacity, and imaging often shows thickening of the intestinal wall. Intravenous vitamin K and plasma supplementation are effective non-surgical strategies. Nevertheless, in instances of severe obstruction and unresponsive hemostasis, surgical resection of necrotic intestinal segments may be necessary. In the cases we reported, we avoided surgery by closely monitoring the coagulation function. Therefore, we suggest that identifying and correcting the impaired coagulation status of patient is essential for timely and appropriate treatment.

Anticoagulation in Acute Neurological Disease

While anticoagulation and its reversal have been of clinical relevance for decades, recent academic and technological advances have expanded the repertoire of its application in neurological disease. The advent of direct oral anticoagulants provides effective, mechanistically elegant, and relatively safer therapeutic options than warfarin for eligible patients at risk for neurological sequelae of prothrombotic states, particularly given the recent availability of corresponding reversal agents. In this review, we examine the provenance, indications, safety, and reversal tools for anticoagulant medications in the context of neurological disease, with specific attention to acute ischemic stroke, cerebral venous sinus thrombosis, and intracerebral hemorrhage. We will use specific clinical scenarios to illustrate the complex factors that must be considered in the use of anticoagulation, including intracranial pathology such as intracerebral hemorrhage, traumatic brain injury, or malignancy; metabolic complications such as chronic kidney disease; pregnancy; and advanced age.

Overlooked complication of anticoagulant therapy: The intramural small bowel hematoma-A case report

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Intramural small bowel hematoma is a haemorrhagic complication of anticoagulant therapy.

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Abdominal complaints and elevated INR value should prompt suspicion.

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CT scan is the preferred imaging method.

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Immediate suspension of anticoagulant drugs and antidote administration is required.

Introduction

Intramural small bowel hematoma is a rare, and often overlooked consequence of anticoagulant therapy. In this report we present such a case in order to bring forth awareness to this entity, and its management.

Presentation of case

We report a 81-year old male who presented with abdominal pain for 2 days. He had been under anticoagulant therapy with warfarin for 9 years, presenting with an elevated INR of 6,2. Intramural small bowel hematoma was confirmed with abdominal ultrasound and CT scan. The patient was treated conservatively with anticoagulant suspension and administration of antidote, and was subsequently discharged after 6 days.

Discussion

Abdominal complaints and an elevated INR value point to the possible diagnosis of intramural small bowel hematoma, however these abdominal symptoms can vary between a mild pain and an established acute abdomen. CT scan showing symmetric bowel thickening associated with some luminal narrowing confirms the diagnosis. In terms of management, there are not sufficient papers to support a standardized treatment; currently the most accepted approach seems to be conservative treatment after the exclusion of complications that would call for surgery.

Conclusion

Anticoagulant therapy is becoming a widespread prescription as the population ages, and intramural small bowel hematoma is one consequence in need of consideration

Stroke Recurrence and its Prevention in Patients with Patent Foramen Ovale

BACKGROUND

It is unclear whether medical or invasive (surgical or catheter interventional) treatment is preferable to prevent recurrence of cerebral ischemia in patients with patent foramen ovale (PFO) as the suspected cause of stroke and what the role of concomitant risk factors is in stroke recurrence.

METHODS

Over a period of ten years, 124 patients (mean age 51 +/- 15 years) with cryptogenic cerebral ischemia and PFO were included into the study and prospectively followed over a mean of 52 +/- 32 months. Of these, 83 were treated medically, 34 underwent transcatheter closure, and seven had surgical closure of the foramen. Of the medically treated patients, 11 stopped medication during follow-up. Recurrent ischemic events and risk factors for recurrence were analyzed.

RESULTS

Annual stroke recurrence rates were generally low and comparable in catheter and medically treated patients, and in patients who had stopped medication (2.9%/2.1%2.2%/year). Patients suffering from recurrence after transcatheter closure (n = 2) both had residual shunts. No stroke recurrence was observed in the few surgically treated patients. An atrial septal aneurysm was not a predictor of recurrent or multiple strokes (p > 0.05, OR = 0.31, and OR = 0.74). Large shunts and a history of previous ischemic events were considerably more frequent in patients with recurrent strokes (p < 0.05, OR = 5.0, and OR = 4.4). Pulmonary embolism and case fatality rates were significantly higher in patients with stroke recurrence (p < 0.001, and p < 0.01).

CONCLUSIONS

The absolute risk of recurrent cerebrovascular events in patients with PFO receiving medical or catheter interventional therapy is low. The small group of untreated patients had a comparably low rate of stroke recurrences. Previous ischemic events and shunt size were risk factors in this observational study. Given conflicting findings across multiple studies, enrollment into a randomized controlled trial would be the optimal choice.

Intracerebral haemorrhages and oral anticoagulation in the north of Scotland

The aim of this study has been twofold: 1--to examine the impact of oral anticoagulant (OAC) use on a possible recent rise in the admission rate of intracerebral haemorrhages to Aberdeen Royal Infirmary (ARI), and 2--to estimate the absolute risk of intracranial haemorrhage for outpatients followed up in the OAC Clinic at ARI. The number of patients admitted to ARI with intracerebral bleedings increased by 60% between 1993 and 1998. A corresponding increase in the proportion of patients with concurrent OAC use (4.7% vs 15.7%, p = 0.055) cannot sufficiently explain the increase in the total number of intracerebral haemorrhages. The average annual incidence of intracranial haemorrhages for the OAC Clinic at ARI is found to be acceptably low at 0.33% per year. Further audit of the large number of patients receiving warfarin outwith the supervision of the clinic is urgently required.

Anticoagulants for preventing stroke in patients with nonrheumatic atrial fibrillation and a history of stroke or transient ischemic attacks

BACKGROUND

People with nonrheumatic atrial fibrillation who have had a transient ischemic attack or a minor ischemic stroke are at risk of recurrent stroke.

OBJECTIVES

The objective of this review was to assess the effect of anticoagulants for secondary prevention, after a stroke or transient ischaemic attack, in patients with nonrheumatic atrial fibrillation.

SEARCH STRATEGY

The reviewer searched the Cochrane Stroke Group trials register and contacted trialists.

SELECTION CRITERIA

Randomised trials comparing oral anticoagulants (target International Normalised Ratio range 2.5 to 4.0) with control or placebo in people with nonrheumatic atrial fibrillation and a previous transient ischaemic attack or minor ischaemic stroke.

DATA COLLECTION AND ANALYSIS

One reviewer assessed trial quality and extracted data.

MAIN RESULTS

Two trials involving 485 people were included. Anticoagulants reduced the risk of recurrent stroke by two-thirds (odds ratio 0.36, 95% confidence interval 0.22 to 0.58). The risk of all vascular events was shown to be almost halved by treatment (odds ratio 0.55, 95% confidence interval 0.37 to 0.82). No intracranial bleeds were reported among people given anticoagulants.

REVIEWER'S CONCLUSIONS

The evidence suggests that anticoagulants are beneficial, without serious adverse effects, for people with nonrheumatic atrial fibrillation and recent cerebral ischaemia.

Bleeding complications of oral anticoagulant treatment: an inception-cohort, prospective collaborative study (ISCOAT). Italian Study on Complications of Oral Anticoagulant Therapy

BACKGROUND

Bleeding is the most serious complication of the use of oral anticoagulation in the prevention and treatment of thromoboembolic complications. We studied the frequency of bleeding complications in outpatients treated routinely in anticoagulation clinics.

METHODS

In a prospective cohort from thirty-four Italian anticoagulation clinics, 2745 consecutive patients were studied from the start of their oral anticoagulation (warfarin in 64%, acenocourmarol in the rest). The target anticoagulation-intensity was low (international normalised ratio [INR] < or = 2.8) in 71% of the patients and high (> 2.8) in the remainder. We recorded demographic details and the main indication for treatment and, every 3-4 months, INR and outcome events. Such events included all complications (bleeding, thrombosis, other), although only bleeding events are reported here, and deaths. We divided bleeding into major and minor categories.

FINDINGS

43% of the patients were women. Nearly three-fifths of the patients were aged 60-79; 8% were over 80. The main indication for treatment was venous thrombolism (33%), followed by non-ischaemic heart disease (17%). Mean follow-up was 267 days. Over 2011 patient-years of follow-up, 153 bleeding complications occurred (7.6 per 100 patient-years). 5 were fatal (all cerebral haemorrhages, 0.25 per 100 patient-years), 23 were major (1.1), and 125 were minor (6.2). The rate of events was similar between sexes, coumarin type, size of enrolling centre, and target INR. The rate was higher in older patients: 10.5 per 100 patient-years in those aged 70 or over, 6.0 in those aged under 70 (relative risk 1.75, 95% Cl 1.29-2.39, p < 0.001). The rate was also higher when the indication was peripheral and/or cerebrovascular disease than venous thromboembolism plus other indications (12.5 vs 6.0 per 100 patient-years) (1.80, 1.2-2.7, p < 0.01), and during the first 90 days of treatment compared with later (11.0 vs 6.3, 1.75, 1.27-2.44, p < 0.001). A fifth of the bleeding events occurred at low anticoagulation intensity (INR < 2, rate 7.7 per 100 patient-years of follow-up). The rates were 4.8, 9.5, 40.5, and 200 at INRs 2.0-2.9, 3-4.4, 4.5-6.9, and over 7, respectively (relative risks for INR > 4.5, 7.91, 5.44-11.5, p < 0.0001).

INTERPRETATION

We saw fewer bleeding events than those recorded in other observational and experimental studies. Oral anticoagulation has become safer in recent years, especially if monitored in anticoagulation clinics. Caution is required in elderly patients and anticoagulation intensity should be closely monitored to reduce periods of overdosing.

Optimal oral anticoagulant therapy in patients with nonrheumatic atrial fibrillation and recent cerebral ischemia

BACKGROUND

A number of studies have demonstrated the efficacy of oral anticoagulant therapy in reducing the risk of stroke and systemic embolism in patients with nonrheumatic atrial fibrillation. However, both the targeted and the actual levels of anticoagulation differed widely among the studies, and a number of studies failed to report standardized prothrombin-time ratios as international normalized ratios (INRs). We therefore performed an analysis to determine the intensity of oral anticoagulant therapy in nonrheumatic atrial fibrillation that provides the best balance between the prevention of thromboembolism and the occurrence of bleeding complications.

METHODS

We calculated INR-specific incidence rates for both ischemic and major hemorrhagic events occurring in 214 patients who received anticoagulant therapy in the European Atrial Fibrillation Trial, a secondary-prevention trial in patients with nonrheumatic atrial fibrillation and a recent episode of minor cerebral ischemia.

RESULTS

The optimal intensity of anticoagulation was found to lie between an INR of 2.0 and an INR of 3.9. No treatment effect was apparent with anticoagulation below an INR of 2.0. The rate of thromboembolic events was lowest at INRs from 2.0 to 3.9, and most major bleeding complications occurred with treatment at intensities with INRs of 5.0 or above.

CONCLUSIONS

To achieve optimal levels of anticoagulation with the lowest risk in patients with atrial fibrillation and a recent episode of cerebral ischemia, the target value for the INR should be set at 3.0, and values below 2.0 and above 5.0 should be avoided.

Long-term anticoagulant therapy in cerebrovascular disease: does bleeding outweigh the benefit?

OBJECTIVE

The aim of the present study was to determine the risk of major haemorrhagic complications, stroke and other cardiovascular events, and mortality during long-term anticoagulant therapy (ACT) in patients with cerebrovascular disease not included in any prospective trials.

DESIGN

The data were collected retrospectively.

SETTING

All patients with symptomatic cerebrovascular disease discharged from the Stroke Unit, Aker University Hospital, Oslo, with ACT (warfarin) during 1983 through to 1986 were included.

SUBJECTS

The material consists of 161 patients with a mean age of 67.8 (range 40-90) years. The reason for initiating ACT was frequent transient ischaemic attacks (TIAs) in 52 patients, stroke in progression (SIP) in 33 patients, and probable embolic stroke in 76 patients. International normalized ratio (INR) of 4.2-2.8 was aimed at.

MAIN OUTCOME MEASURES

Major haemorrhagic complications, recurrent stroke and survival was determined for the total material, and in the subgroups non-valvular atrial fibrillation (NVAF, n = 49), TIAs, and SIP.

RESULTS

The mean duration of ACT was 21.1 (range 0.5-60.2) months with a total of 282.9 patient-years. The rate of major (including fatal) haemorrhagic complications was 4.6% per year, and the rate of fatal haemorrhagic complications was 1.4% per year. The complication rates in the subgroups of patients did not differ significantly from that in the total material. Only two out of the 13 major haemorrhagic complications occurred during the initial 6 months of ACT. No strokes occurred in the TIA subgroup. The rate of recurrent stroke (excluding intracranial haemorrhage) was 3.9% per year for all patients, 4.7% per year for the patients with NVAF, and 4.2% per year for the patients with SIP.

CONCLUSIONS

The total results suggest a positive net effect of ACT in patients with NVAF and TIAs. Without comparable data, no definite conclusions concerning the effect of ACT on patients with SIP can be drawn. The rate of bleeding complications was similar to that in other studied materials and is not negligible. In patients with SIP and TIAs, ACT beyond 6 months should probably only be continued if aspirin is not tolerated or has proven ineffective in the particular patient.

Antithrombotic therapy in acute ischaemic stroke: an overview of the completed randomised trials

A formal statistical overview of all truly randomised trials was undertaken to determine whether antithrombotic therapy is effective and safe in the early treatment of patients with acute stroke. There were 15 completed randomised controlled trials of the value of early antithrombotic treatment in patients with acute stroke. The regimes tested in acute presumed or confirmed ischaemic stroke were: heparin, 10 trials with 1047 patients: oral anticoagulants, one trial with 51 patients: antiplatelet therapy, three trials with 103 patients. Heparin was tested in one trial with 46 patients with acute haemorrhagic stroke. Outcome measures were deep venous thrombosis (confirmed by I125 scanning or venography), pulmonary embolism, death from all causes, haemorrhagic transformation of cerebral infarction, level of disability in survivors. In patients with acute ischaemic stroke, allocation to heparin was associated with a highly significant 81% (SD 8, 2p < 0.00001) reduction in deep venous thrombosis detected by I125 fibrinogen scanning or venogram. Only three trials systematically identified pulmonary emboli, which occurred in 6/106 (5.7%) allocated control vs 3/132 (2.3%) allocated heparin, a non-significant 58% reduction (SD 45.7, 2p > 0.1). There were relatively few deaths in the trials in patients with presumed ischaemic stroke: 94/485 (19.4%) among patients allocated to the control group vs 79/497 (15.9%) among patients who were allocated heparin. The observed 18% (SD 16) reduction in the odds of death was not statistically significant. The least biased estimated of the effect of treatment on haemorrhagic transformation of the cerebral infarct (HTI) comes from trials where all patients were scanned at the end of treatment, irrespective of clinical deterioration; using this analysis, haemorrhagic transformation occurred in 7/102 (6.9%) control vs 8/106 (7.5%) treated, a non-significant 12% increase (SD 56, 2p > 0.1). These data cannot exclude the possibility that heparin substantially increases the risks of HTI. No data on disability in survivors could be obtained. Early heparin treatment might be associated with substantial reductions in deep venous thrombosis (and probably also pulmonary embolism) and possibly a one fifth reduction in mortality (equivalent to the avoidance of 20-40 early deaths per thousand patients treated.) However, the data were wholly inadequate on safety, particularly on the risk of haemorrhagic transformation of the infarct and on the hazards of heparin therapy in patients with known intracerebral haemorrhage. The trials of oral anticoagulants (15 deaths among 57 patients) and antiplatelet therapy (two deaths among 103 patients) were too small to be informative. Much larger randomized trials-comparing aspirin, heparin and the combination of both drugs against control-in patients with acute ischaemic stroke are justified (and several are now planned or underway).

In vivo pharmacology of aprosulate, a new synthetic polyanion with anticoagulant activity

The in vivo effects of a new synthetic inhibitor of blood coagulation, aprosulate sodium, were investigated. Intravenous bolus injection of aprosulate or standard heparin in rats produced an immediate prolongation of the APTT which were characterized by a moderate dose-dependency and long-lasting duration when compared with those of standard heparin. Standard heparin inhibited plasma factor Xa activity, but aprosulate did not even at the highest dose used. Both agents inhibited thrombus formation in a dose-dependent manner in an arterio-venous shunt model. At antithrombotic doses, standard heparin prolonged the bleeding time measured by the tail transection method, but aprosulate did not. The present results suggest that aprosulate has promising in vivo profile as an anticoagulant and antithrombotic agent.

Deep vein thrombosis in stroke patients: An overview

Deep vein thrombosis (DVT) is prevalent both in the acute and the later phases of stroke. From previous studies using (125)I fibrinogen uptake, its peak incidence appears to occur during the first 10 days of stroke. Using venography and impedance plethymography, its prevalence is still high (between 30% and 40%) 1 1/2 to 6 months after stroke. The incidence of pulmonary embolism appear to diminish after the acute phase of stroke. Venous stasis is a widely accepted factor in the cause of DVT. More recently, venous injury as endothelial damage from excessive venodilation has been postulated. Increased venous size in hemiplegic limb has been reported. Further studies as to the role of decreased venous velocity and increased venous size and the effect of various modalities influencing these effects are needed. Routine screening of stroke patients appears indicated, but what protocol should be followed has yet to be determined. Selective screening by stratifying patients as to their clinical risk may be appropriate if found safe and cost-effective. Prophylactic treatment should be initiated in patients who are at increased risk of DVT. The prophylaxis of venous thrombosis in stroke patients remains uncertain. The use of low-molecular heparin may be a promising option if it is proven safe, efficacious, and causes less bleeding. Other prophylactic methods remain to be investigated.

Bleeding complications to oral anticoagulant therapy: multivariate analysis of 1010 treatment years in 551 outpatients

One thousand and ten patient years of oral anticoagulant therapy with vitamin-K-antagonists were reviewed with regard to major bleeding complications. The incidence of bleeding that necessitated hospital admission was 2.7% per year (95% confidence limits, 1.7-3.7%). The major source of bleeding was the alimentary tract, whereas no cases of intracranial bleeding were found. Various factors with potential effects on the bleeding risk were evaluated by multivariate statistical analysis, and the following independent risk factors were identified: age greater than 75 years and hypertension increased the bleeding risk by 10.5% and 4.5%, respectively. Each recorded prothrombin value significantly below the therapeutic range increased the bleeding risk by 3.9%, and each year of treatment increased the risk by 2.0%. These figures may be used to estimate the risk of major bleeding in an individual patient. Current treatment with thiazide diuretics was found to increase the bleeding risk by 5.2%. However, this observation requires further documentation and analysis. Although no lethal episodes of bleeding occurred, the developing field of indications for oral anticoagulant therapy should be considered on the basis of a continuous substantial risk of major bleeding.

Antithrombotic treatment of cerebrovascular disease

The most common type of cerebrovascular disease is ischaemia or infarction from atherothrombosis or cardiac embolism. Antithrombotic treatment with an antiplatelet agent or anticoagulant assumes a prior clinical classification into categories of transient ischaemic attack (TIA) or minor stroke, acute partial stable stroke, stroke-in-progression, and completed stroke. Aspirin reduces the risk of stroke, myocardial infarction, and death after TIA or minor stroke secondary to atherothrombosis. Aspirin is effective in both sexes at a dose of 300 or 1200 mg/day. Ticlopidine (500 mg/day), a new antiplatelet agent, is more effective than aspirin in preventing stroke and death in patients with TIA or minor stroke. Ticlopidine (500 mg/day) is effective in preventing recurrent stroke, myocardial infarction, or vascular death in patients with completed stroke. Aspirin has not been directly shown to be effective after completed stroke. No clear evidence exists for the use of anticoagulants in atherothrombotic cerebral vascular disease in patients presenting with TIA or minor stroke, acute partial stable stroke, stroke-in-progression, or completed stroke. Anticoagulation for rheumatic valvular heart disease is effective in preventing recurrent embolism. Long-term anticoagulation of patients with mechanical prosthetic valves protects against initial embolism and prevents recurrent embolism. The addition of aspirin (500-1000 mg/day) to warfarin reduces the rate of cerebral embolism from mechanical prosthetic heart valves but is associated with increased bleeding. The addition of dipyridamole (400 mg/day) to warfarin may be more effective than aspirin in reducing the rate of cerebral embolism from mechanical prosthetic heart valves and has fewer bleeding side-effects. Anticoagulation during the hospital phase of myocardial infarction reduces the incidence of systemic embolism/stroke. Long-term anticoagulation of patients after the hospital phase of myocardial infarction reduces the incidence of systemic embolism/stroke, recurrent myocardial infarction and death. Prophylactic anticoagulant treatment of patients with non-valvular atrial fibrillation reduces the incidence of embolism, but the optimal duration of treatment is not known. Immediate anticoagulation of patients with completed cardioembolic stroke is safe and effective in preventing recurrent embolism.

Anticoagulation-related intracranial extracerebral haemorrhage

From January 1981 to June 1986 116 patients with anticoagulation-related intracranial haemorrhage were referred to hospital. Seventy six of these haemorrhages were extracerebral, 69 were in the subdural and seven in the subarachnoid space. No epidural haemorrhages were identified. Compared with non-anticoagulation-related haematomas, the risk of haemorrhage was calculated to be increased fourfold in men and thirteenfold in women. An acute subdural haematoma, mostly due to contusion, was more frequently accompanied by an additional intracerebral haematoma than a chronic subdural haematoma. Trauma was a more important factor in acute subdural haematomas than in chronic. Almost half of the patients (48%) had a history of hypertension, more than a third (35%) had heart disease and about one fifth (18%) were diabetic. Headache was the most frequent initial symptom. Later decreased level of consciousness and focal neurological signs exceeded the frequency of headache. Three patients with subarachnoid haemorrhage and nine patients with acute subdural haematomas died, while those with chronic subdural haematomas all survived and had at the most mild, non-disabling sequelae. Myocardial infarction (22%), pulmonary embolism (20%), and arterial disease (20%) were the most frequent reasons for anticoagulant treatment. Critical review based on established criteria for anticoagulation treatment suggests there was no medical reason to treat a third of these patients. The single most useful measure that could be taken to reduce the risk of anticoagulation-induced intracranial haemorrhage would be to identify patients who are being unnecessarily treated and to discontinue anticoagulants.

Placebo-controlled, randomised trial of warfarin and aspirin for prevention of thromboembolic complications in chronic atrial fibrillation. The Copenhagen AFASAK study

From November, 1985, to June, 1988, 1007 outpatients with chronic non-rheumatic atrial fibrillation (AF) entered a randomised trial; 335 received anticoagulation with warfarin openly, and in a double-blind study 336 received aspirin 75 mg once daily and 336 placebo. Each patient was followed up for 2 years or until termination of the trial. The primary endpoint was a thromboembolic complication (stroke, transient cerebral ischaemic attack, or embolic complications to the viscera and extremities). The secondary endpoint was death. The incidence of thromboembolic complications and vascular mortality were significantly lower in the warfarin group than in the aspirin and placebo groups, which did not differ significantly. 5 patients on warfarin had thromboembolic complications compared with 20 patients on aspirin and 21 on placebo. 21 patients on warfarin were withdrawn because of non-fatal bleeding complications compared with 2 on aspirin and none on placebo. Thus, anticoagulation therapy with warfarin can be recommended to prevent thromboembolic complications in patients with chronic non-rheumatic AF.

Complications of long-term anticoagulation

We used life-table techniques to determine risks of morbidity and mortality associated with long-term warfarin treatment in an anticoagulation clinic. Cumulative risks for life-threatening complications and warfarin-related death among all patients were 1% at 6 months, 5% at 1 year, and 7% at 2 and 3 years. Cox regression analysis using age as a continuous variable failed to show an effect of age on cumulative risks of complication. The occurrence of a minor complication during the course of therapy did not place patients at higher risk for developing a major complication that would prompt discontinuation of therapy or cause death. There was no statistically significant difference between the cumulative risks of patients anticoagulated for cerebrovascular disease and the cumulative risks of patients anticoagulated for other indications.

Carotid endarterectomy. Who needs it?

Although carotid endarterectomy is one of the most frequently performed operations in this country, recent evidence casts doubt on its advisability, particularly for patients with ocular manifestations of cerebral ischemia. The following evidence is that: the risk of future stroke in untreated patients with amaurosis fugax, retinal plaques, and infarcts is less than 3% per year, far lower than that expected for cerebral (hemispheric) transient ischemic attacks (TIAs); the perioperative risk of stroke and death after endarterectomy may be much higher than previously suspected; and aspirin is a comparatively risk-free and moderately effective alternative to endarterectomy. Because of the questions raised about the risk-to-benefit ratio of endarterectomy, patients with ocular manifestations of cerebral ischemia should be considered for this operation only as part of a proposed randomized collaborative study.