Intracranial hemorrhage due to long-term anticoagulant therapy in patients with prosthetic heart valves--four case reports

Timing of vitamin K antagonist re-initiation following intracranial hemorrhage in mechanical heart valves: Systematic review and meta-analysis

BACKGROUND

While evidence supports resumption of vitamin K antagonists (VKAs) among mechanical heart valve (MHV) patients presenting with anticoagulant-associated intracranial hemorrhage (ICH), ideal timing of resumption is uncertain.

OBJECTIVE

To determine the optimal timing of VKA re-initiation and its associated clinical outcomes.

METHODS

We performed a systematic review and a meta-analysis of studies published from January 1950 to August 2015. We extracted data on the location of initial ICH, use of cranial surgery, presence of atrial fibrillation, MHV type and position, number of MHVs, and timing of VKA resumption. Outcomes including valve thrombosis, thromboembolic events or ICH recurrence were recorded. Meta-regression analysis was conducting with controlling for covariates. We calculated absolute risks, and assessed the effect of anticoagulant resumption timing on ICH recurrence.

RESULTS

23 case-series and case-reports were identified. Overall ICH recurrence was 13% (95% confidence interval [CI], 7%-25%), while valve thrombosis and ischemic strokes occurred at 7% (95% CI, 3%-17%) and 12% (95% CI, 5%-23%) respectively. A trend towards lower ICH recurrence was observed with delayed VKA resumption (slope estimate -0.2154, p=0.10). Recurrence rate ranged from 50% with VKA resumption at 3days to 0% with resumption at 16days.

CONCLUSION

Among patients with MHV, there is inadequate data to suggest an optimal timing of VKA re-initiation following an ICH, though delayed restart appears to be protective against recurrence but is associated with higher risk of thrombosis. Our analysis suggests 4-7days might be an ideal time with least risk of thrombosis or ICH recurrence.

A multicenter, prospective, observational study of warfarin-associated intracerebral hemorrhage: The SAMURAI-WAICH study

BACKGROUND

Because patients with warfarin-associated intracerebral hemorrhage (WAICH) have a high risk of ongoing bleeding, disability, and death, urgent coagulopathy reversal should be considered. On the other hand, thromboembolism may occur with reversal or withholding of anticoagulant therapy. The current status of acute hemostatic treatments and clinical outcomes in WAICH patients was investigated.

METHODS

WAICH patients admitted within 3 days of onset were prospectively enrolled in 10 stroke centers. Thromboembolic and hemorrhagic complications and functional outcomes were followed-up for one year.

RESULTS

Of 50 WAICH patients (31 men, 73 ± 9 years old) enrolled, all stopped warfarin on admission. Elevated prothrombin time-international normalized ratios (PT-INR) were normalized in 43 (86%). Anticoagulant therapy was resumed with intravenous full-dose unfractionated heparin followed by warfarin in 9 (18%), intravenous low-dose unfractionated heparin followed by warfarin in 14 (28%) and warfarin alone in 14 (28%) at a median of 2.5 (IQR 1.25-9), 4 (2-5.5) and 6 (3-11) days after onset, respectively, after emergent admission. Onset-to-admission time (per 1-hour increase; OR 0.55, 95% CI 0.19-0.84) was inversely associated with hematoma expansion. Anticoagulant therapy was resumed with intravenous full-dose unfractionated heparin in 9 (18%), low-dose heparin in 14 (28%) and warfarin alone in 14 (28%) at a median of 2.5, 4 and 6 days after onset, respectively. During one-year follow-up (n=47), 11 thromboembolic and 6 hemorrhagic complications were documented. Twenty four patients showed unfavorable outcomes, corresponding to a modified Rankin Scale score of 4-6. Thromboembolic complications (OR, 10.62; 95% CI, 1.05-227.85), as well as advanced age (per 1 year; OR, 1.27; 95% CI, 1.10-1.61) and higher National Institutes of Health Stroke Scale (NIHSS) score (per 1 point; OR, 1.24; 95% CI 1.07-1.55), were independently associated with unfavorable outcome.

CONCLUSIONS

PT-INR normalization on admission and early anticoagulant resumption were common in WAICH patients. Thromboembolic complications were independently associated with unfavorable outcome.

Survey of neurosurgical management of central nervous system hemorrhage in patients receiving anticoagulation therapy: current practice is highly variable and may be suboptimal

BACKGROUND

Patients with central nervous system (CNS) hemorrhage who receive anticoagulation (AC) therapy are at high risk for progressive or recurrent hemorrhagic and thromboembolic (TE) events. The authors conducted a survey at the 2010 American Association of Neurological Surgeons (AANS) annual meeting to determine how these patients are currently being managed by neurosurgeons.

METHODS

During plenary session III at the 2010 AANS annual meeting, the audience was presented with an illustrative case and surveyed with an audience response system. The number choosing each response as well as data regarding the level of training of meeting registrants were provided to the authors by the AANS.

RESULTS

Approximately 10% of all meeting registrants responded to the questions, 65% of whom were consultant neurosurgeons. The responses showed that 47.7% of respondents face dilemmas regarding AC restart time and intensity at least once per week. The most commonly selected AC restart time was 1 month after the index hemorrhage (43.5%); 8.0% indicated they would not restart AC. In making management decisions in these patients, 59.4% of respondents indicated that they relied predominantly on their own intuition or past experience.

CONCLUSIONS

This study is the first to describe how patients with CNS hemorrhage who receive AC therapy are currently being managed by clinicians. An apparent neurosurgical preference to avoid hemorrhagic complications is at odds with a suggested early risk for TE. These data suggest that the neurosurgical management of patients with CNS hemorrhage who receive AC therapy is an area that could benefit from consensus-based practice guidelines and an organized effort at knowledge translation and mobilization.

Management of anticoagulation following central nervous system hemorrhage in patients with high thromboembolic risk

SUMMARY BACKGROUND

Patients who present with central nervous system (CNS) hemorrhage while on anticoagulation (AC) for thromboembolic (TE) risk factors are a challenge to manage.

OBJECTIVE

We sought to inform decisions surrounding the timing and intensity of AC resumption by performing a systematic review.

METHODS

Three reviewers screened publications from Medline and EMBASE and extracted data. Hemorrhagic and TE adverse events that occurred subsequent to the index hemorrhage were recorded, as was their timing relative to presentation and covariates that might influence their occurrence.

RESULTS

Data were extracted from 63 publications detailing 492 patients; 7.7% of patients experienced hemorrhagic complications and 6.1% experienced TE complications. Hemorrhagic complications were more common within 72 h of presentation while TE complications were more common thereafter. Patients restarted on AC after 72 h were significantly more likely to have a TE complication (P = 0.006) and those restarted before 72 h were more likely to hemorrhage (P = 0.0727). Factors associated with re-hemorrhage included younger age, traumatic cause, subdural hematomas and failure to reverse AC. TE complications were more common in younger patients and those with spinal hemorrhage, multiple hemorrhages, and non-traumatic causes of the index hemorrhage. Re-initiation of AC at a lower intensity also significantly increased the risk of TE complications.

INTERPRETATION

Our results suggest that it may be prudent to re-initiate AC earlier than previously thought, with the timing and intensity modified based on predictors of TE and hemorrhagic complications. These findings must be explored in a prospective study because of limitations inherent to the analyzed studies.

Systematic review of observational research studying the long-term use of antithrombotic medicines following intracerebral hemorrhage

Patients with intracerebral hemorrhage frequently have indications for antithrombotic therapy. This represents a therapeutic dilemma as intracerebral hemorrhage is considered a contraindication to antithrombotic medication. Previous systematic reviews have revealed no long-term randomised studies addressing this issue. Our objective was to review observational studies describing the long-term follow-up of patients receiving antithrombotic therapy following intracerebral hemorrhage. Searches were conducted in MEDLINE and EMBASE from 1984 to 2008 for any observational studies detailing use of antithrombotic treatments in patients with intracerebral hemorrhage. Included studies must have had follow-up extending beyond discharge. The primary endpoint was recurrent intracerebral hemorrhage. Secondary endpoints were ischemic events and serious vascular events. 1,301 articles were reviewed: two epidemiological studies and six case series met the inclusion criteria. These described a total of 46 subjects receiving antiplatelet agents (from one study) and 42 patients receiving oral anticoagulants (from one study and six case-series). For patients receiving subsequent aspirin there were seven recurrent intracerebral hemorrhages and four subsequent thrombo-occulsive events. Amongst patients restarting oral anticoagulation there were four recurrent intracerebral bleeds and nine subsequent thrombo-occulsive events. There is a marked paucity of evidence to guide clinicians when planning the long-term management of patients with intracerebral hemorrhage and cogent indications for antithrombotic therapy. Published guidance addressing this issue is not evidence based. In the continued absence of randomised studies addressing antithrombotic use following intracerebral hemorrhage, there is a clear requirement for further high quality observational data on the clinical impact of antithrombotic therapy in this important patient group.

Treatment of warfarin-associated intracerebral hemorrhage: literature review and expert opinion

Wider use of oral anticoagulants has led to an increasing frequency of warfarin-related intracerebral hemorrhage (ICH). The high early mortality of approximately 50% has remained stable in recent decades. In contrast to spontaneous ICH, the duration of bleeding is 12 to 24 hours in many patients, offering a longer opportunity for intervention. Treatment varies widely, and optimal therapy has yet to be defined. An OVID search was conducted from January 1996 to January 2006, combining the terms warfarin or anticoagulation with intracranial hemorrhage or intracerebral hemorrhage. Seven experts on clinical stroke, neurologic intensive care, and hematology were provided with the available information and were asked to independently address 3 clinical scenarios about acute reversal and resumption of anticoagulation in the setting of warfarin-associated ICH. No randomized trials assessing clinical outcomes were found on management of warfarin-associated ICH. All experts agreed that anticoagulation should be urgently reversed, but how to achieve it varied from use of prothrombin complex concentrates only (3 experts) to recombinant factor VIIa only (2 experts) to recombinant factor VIIa along with fresh frozen plasma (1 expert) and prothrombin complex concentrates or fresh frozen plasma (1 expert). All experts favored resumption of warfarin therapy within 3 to 10 days of ICH in stable patients in whom subsequent anticoagulation is mandatory. No general agreement occurred regarding subsequent anticoagulation of patients with atrial fibrillation who survived warfarin-associated ICH. For warfarin-associated ICH, discontinuing warfarin therapy with administration of vitamin K does not reverse the hemostatic defect for many hours and is inadequate. Reasonable management based on expert opinion includes a wide range of additional measures to reverse anticoagulation in the absence of solid evidence.

Traumatic Head Injury in the Anticoagulated Elderly Patient: A Lethal Combination

Warfarin is the most common oral anticoagulant used for chronic anticoagulation therapy. Even without any antecedent trauma overanticoagulation can result in intracranial hemorrhage. The triad of anticoagulation with warfarin, age greater than 65 years, and traumatic head injury frequently produces a lethal brain hemorrhage. A retrospective review of more than 2000 patients admitted to the Trauma Service between September 1998 and May 2000 produced 278 patients with head injury and CT-documented intracranial hemorrhage. Of these patients 21 were admitted with an elevated prothrombin time (FT) due to anticoagulation with warfarin. Eighteen patients (86%) were above the age of 70. The most common indications for anticoagulation were atrial fibrillation (71%), deep venous thrombosis (19%), aortic valve replacement (9%), and ischemic cerebral infarcts (9%). Fourteen injuries were the result of a fall, one resulted from a gunshot wound, and one resulted from an assault. The remaining five patients were excluded as their history, workup, and evaluation by neurosurgery suggested a spontaneous bleed leading to fall rather than a fall causing a traumatic bleed. The average Glasgow Coma Score on admission was 11. The average PT and International Normalized Ratio (INR) on admission were 19.2 and 2.99 respectively. Eight of the 16 patients analyzed died. The risk of intracranial hemorrhage with relatively minor head injury is increased dramatically in the anticoagulated patient. A mortality rate of 50 per cent far exceeds the mortality rate in patients with similar head injuries who are not anticoagulated. In addition the risk/benefit equation of anticoagulation for the elderly is more complex and differs from that for younger patients. Perhaps more frequent and judicious monitoring of prothrombin time levels with lower therapeutic ranges (INR 1.5–2) is necessary.

Management of oral anticoagulant-induced intracranial haemorrhage

Intracranial haemorrhage is an infrequent but often fatal complication of oral anticoagulant therapy which will become more common as anticoagulant use increases. The risk of anticoagulant-induced intracranial haemorrhage may be reduced by judicious prescribing, identification of patients at high risk of bleeding, and close monitoring by experienced staff. The presenting features of intracranial haemorrhage are often vague and physicians should be aware of the need for urgent investigation of all anticoagulated patients with neurological symptoms. Current guidelines for immediate reversal of anticoagulation recommend administration of vitamin K1 and factor replacement with either factor concentrates or fresh frozen plasma. In this review we discuss recent evidence suggesting prothrombin complex concentrates lead to faster, and more complete, correction of coagulation and, in the context of intracranial bleeding, may be associated with improved neurological status. Evidence for the risks of short-term cessation of anticoagulants, in the immediate period following an intracranial haemorrhage, and their subsequent reintroduction is also discussed.