The incidence of heparin-induced thrombocytopenia Type II in patients with subarachnoid hemorrhage treated with heparin versus enoxaparin

Bivalirudin as a substitute for heparin in neurointervention for patients with heparin-induced thrombocytopenia

OBJECTIVES

Heparin-induced thrombocytopenia is a known complication of heparin exposure with potentially life-threatening sequelae. Direct thrombin inhibitors can be substituted for heparin in patients with heparin-induced thrombocytopenia that require anticoagulation. However, the use of direct thrombin inhibitors as a substitute for heparin has not been widely reported in the neuroendovascular literature.

MATERIALS AND METHODS

Here we report the first use of the direct thrombin inhibitor bivalirudin in a neuroendovascular procedure as a substitute for heparin in a patient with a ruptured pseudoaneurysm and heparin-induced thrombocytopenia, and review the literature on the use of bivalirudin and argatroban for such patients.

RESULTS

Bivalirudin was safely and effectively used in the case reported, with no thrombotic or hemorrhagic complications. Our literature review revealed a paucity of studies on the use of heparin alternatives, including bivalirudin, in neuroendovascular procedures in patients with heparin-induced thrombocytopenia.

CONCLUSIONS

Heparin-induced thrombocytopenia is an important iatrogenic disease process in patients undergoing neuroendovascular procedures, and developing protocols to diagnose and manage heparin-induced thrombocytopenia is important for healthcare systems. While further research needs to be done to establish the full range of anticoagulation options to substitute for heparin, our case indicates bivalirudin as a potential candidate.

Outcomes of heparin-induced thrombocytopenia type II in aneurysmal subarachnoid hemorrhage patients: A US nationwide analysis

BACKGROUND

Despite the widespread use of heparin during and following endovascular procedures in the management of aneurysmal subarachnoid hemorrhage (SAH) patients, limited research has explored the incidence and impact of heparin-induced thrombocytopenia (HIT) on SAH.

METHODS

Descriptive statistics, multivariate regressions, and propensity score-matching were employed to compare clinical characteristics, comorbidities, interventions, complications, and outcomes of HIT in SAH patients identified within the US National Inpatient Sample database from 2010 to 2019.

RESULTS

Among 76 387 SAH patients from 2010 to 2019, 166 (0.22%) developed HIT. HIT was identified as a significant predictor of prolonged length of stay (OR 6.799, 95% CI 3.985 to 11.6, P<0.01) and poor functional outcomes (OR 2.541, 95% CI 1.628 to 3.966, P<0.01) after adjusting for relevant factors. HIT incidence was higher in patients with elevated SAH severity scores (1.42 vs 1.06, P<0.01), younger patients (58.04 vs 61.39 years, P=0.01), overweight individuals (0.4% vs 0.2%, P<0.01), those on long-term anticoagulants (10.84% vs 5.72%, P<0.01), or with a cerebrospinal fluid drainage device (external ventricular drain, ventriculoperitoneal shunt; P<0.01). HIT patients showed increased rates of endovascular coiling, ventricular drain placement, shunt placement, deep vein thrombosis, urinary tract infection, acute kidney injury, pulmonary embolism, venous sinus thrombosis, pneumonia, and cerebral vasospasm (all P<0.01).

CONCLUSION

SAH patients with HIT exhibited various comorbidities and increased rates of complications, which may contribute to extended hospital stays. This nationwide study aids clinical suspicion and highlights HIT's impact on SAH patients.

An institutional report of heparin induced thrombocytopenia type II in aneurysmal subarachnoid hemorrhage patients

BACKGROUND

Heparin induced thrombocytopenia Type II (HIT-II) is a dangerous thromboembolic complication of heparin therapy. The current literature on incidence and outcomes of HIT-II in aneurysmal subarachnoid hemorrhage (aSAH) patients remains sparse.

OBJECTIVE

We report our institution's incidence and outcomes of HIT-II in aSAH patients.

METHODS

We performed a retrospective cohort study at an academic medical center between June 2014 and July 2018. All patients had aSAH confirmed by digital subtraction angiography. Diagnosis of HIT-II was determined by positive results on both heparin PF4-platelet antibody ELISA (anti-PF4) and serotonin release assay (SRA).

RESULTS

204 patients met inclusion criteria. Seven patients (7/204, 3.5%) underwent laboratory testing, three of whom met clinical criteria. HIT-II incidence was confirmed in two of these seven patients (2/204, 0.98%), who had high BMI and T4 scores.

CONCLUSION

Our institution's report of HIT-II incidence in aSAH patients is lower than previously reported in this population and more closely parallels HIT-II incidence in the general and surgical ICU setting. Widely-accepted American College of Chest Physicians (ACCP) clinical diagnostic criteria in conjunction with anti-PF4 and SRA testing is the gold standard of clinical diagnosis of HIT-II in aSAH patients.

Refractory Heparin-Induced Thrombocytopenia in a Patient With Subarachnoid Hemorrhage-A Clinical Conundrum

Heparin induced thrombocytopenia (HIT) often resolves with discontinuation of heparin/ heparinoid products. Severe HIT with platelet counts <20,000/µL and disseminated intravascular coagulation is frequently associated with consumptive coagulopathy and systemic thrombosis. Management of severe HIT in patients who fail to improve on discontinuing heparinoid products and argatroban infusion is not well established. We describe a patient admitted with aneurysmal subarachnoid hemorrhage (SAH) who developed severe autoimmune HIT, failed conventional anticoagulation therapy with argatroban and progressed to develop extensive deep venous thrombosis and limb ischemia. She was successfully treated using bivalirudin, immunomodulation with 2 cycles of intravenous immunoglobulin and immunosuppression with methylprednisolone. Refractory severe HIT among SAH patients is rare and pose several therapeutic challenges. We report successful treatment using alternate anticoagulant and immune suppression and modulation.

Heparin and Heparin-Derivatives in Post-Subarachnoid Hemorrhage Brain Injury: A Multimodal Therapy for a Multimodal Disease

Pharmacologic efforts to improve outcomes following aneurysmal subarachnoid hemorrhage (aSAH) remain disappointing, likely owing to the complex nature of post-hemorrhage brain injury. Previous work suggests that heparin, due to the multimodal nature of its actions, reduces the incidence of clinical vasospasm and delayed cerebral ischemia that accompany the disease. This narrative review examines how heparin may mitigate the non-vasospastic pathological aspects of aSAH, particularly those related to neuroinflammation. Following a brief review of early brain injury in aSAH and heparin’s general pharmacology, we discuss potential mechanistic roles of heparin therapy in treating post-aSAH inflammatory injury. These roles include reducing ischemia-reperfusion injury, preventing leukocyte extravasation, modulating phagocyte activation, countering oxidative stress, and correcting blood-brain barrier dysfunction. Following a discussion of evidence to support these mechanistic roles, we provide a brief discussion of potential complications of heparin usage in aSAH. Our review suggests that heparin’s use in aSAH is not only safe, but effectively addresses a number of pathologies initiated by aSAH.

Safety of early pharmacological thromboprophylaxis after subarachnoid hemorrhage

OBJECTIVE

The recent guidelines on management of aneurysmal subarachnoid hemorrhage (aSAH) advise pharmacological thromboprophylaxis (PTP) after aneurysm obliteration. However, no study has addressed the safety of PTP in the aSAH population. Therefore, the aim of this study was to assess the safety of early PTP after aSAH.

METHODS

Retrospective cohort of aSAH patients admitted between January 2012 and June 2013 in a single high-volume aSAH center. Traumatic SAH and perimesencephalic hemorrhage patients were excluded. Patients were grouped according to PTP timing: early PTP group (PTP within 24 hours of aneurysm treatment), and delayed PTP group (PTP started > 24 hours).

RESULTS

A total of 174 SAH patients (mean age 56.3±12.5 years) were admitted during the study period. Thirty-nine patients (22%) did not receive PTP, whereas 135 patients (78%) received PTP after aneurysm treatment or negative angiography. Among the patients who received PTP, 65 (48%) had an external ventricular drain. Twenty-eight patients (21%) received early PTP, and 107 (79%) received delayed PTP. No patient in the early treatment group and three patients in the delayed PTP group developed an intracerebral hemorrhagic complication. Two required neurosurgical intervention and one died. These three patients were on concomitant PTP and dual antiplatelet therapy.

CONCLUSIONS

The initiation of PTP within 24 hours may be safe after the treatment of a ruptured aneurysm or in angiogram-negative SAH patients with diffuse aneurysmal hemorrhage pattern. We suggest caution with concomitant use of PTP and dual antiplatelet agents, because it possibly increases the risk for intracerebral hemorrhage.

Clinical features and risk factor analysis for lower extremity deep venous thrombosis in Chinese neurosurgical patients

Background:

Deep venous thrombosis (DVT) contributes significantly to the morbidity and mortality of neurosurgical patients; however, no data regarding lower extremity DVT in postoperative Chinese neurosurgical patients have been reported.

Materials and Methods:

From January 2012 to December 2013, 196 patients without preoperative DVT who underwent neurosurgical operations were evaluated by color Doppler ultrasonography and D-dimer level measurements on the 3^rd, 7^th, and 14^th days after surgery. Follow-up clinical data were recorded to determine the incidence of lower extremity DVT in postoperative neurosurgical patients and to analyze related clinical features. First, a single factor analysis, Chi-square test, was used to select statistically significant factors. Then, a multivariate analysis, binary logistic regression analysis, was used to determine risk factors for lower extremity DVT in postoperative neurosurgical patients.

Results:

Lower extremity DVT occurred in 61 patients, and the incidence of DVT was 31.1% in the enrolled Chinese neurosurgical patients. The common symptoms of DVT were limb swelling and lower extremity pain as well as increased soft tissue tension. The common sites of venous involvement were the calf muscle and peroneal and posterior tibial veins. The single factor analysis showed statistically significant differences in DVT risk factors, including age, hypertension, smoking status, operation time, a bedridden or paralyzed state, the presence of a tumor, postoperative dehydration, and glucocorticoid treatment, between the two groups (P < 0.05). The binary logistic regression analysis showed that an age greater than 50 years, hypertension, a bedridden or paralyzed state, the presence of a tumor, and postoperative dehydration were risk factors for lower extremity DVT in postoperative neurosurgical patients.

Conclusions:

Lower extremity DVT was a common complication following craniotomy in the enrolled Chinese neurosurgical patients. Multiple factors were identified as predictive of DVT in neurosurgical patients, including the presence of a tumor, an age greater than 50 years, hypertension, and immobility.

Predictors and outcomes of suspected heparin-induced thrombocytopenia in subarachnoid hemorrhage patients

BACKGROUND

Heparin-induced thrombocytopenia (HIT) is a dreaded complication of heparin-related products and correlates with a worse outcome in aneurysmal subarachnoid hemorrhage (SAH) patients.

OBJECTIVE

To study the risk factors and outcomes of SAH patients suspected of having HIT, confirmed as present or absent by the platelet factor 4 (PF4) antibody test.

METHODS

All patients with presumed aneurysmal, nontraumatic SAH and having undergone a PF4 test were identified through our research patient database. Charts, laboratory values and images were analyzed retrospectively.

RESULTS

We identified 166 patients with SAH who were tested for HIT; 42 patients (25%) had a positive antibody test. There was no difference in platelet profiles or mean platelet nadirs of HIT+ and HIT- patients (147 ± 93 vs. 153 ± 86 ×10(9)/l, respectively). Univariate analysis identified gender, magnesium prophylaxis, Fisher group 3, clipping versus coiling, presence of angiographic vasospasm, number of vasospasm treatments, and day of HIT testing as potential risk factors associated with HIT. A multivariate analysis indicated that female gender (OR 8.2, 95% CI 2.0-33.2), greater number of vasospasm treatments (OR 1.5, 95% CI 1.2-2.0), later day of HIT testing (OR 1.2, 95% CI 1.1-1.3), and clipping (OR 5.0, 95% CI 1.42-10.0) were independently associated with HIT positivity. HIT+ patients showed more infarcts on CT, longer ICU and hospital stays and worse modified Rankin Scale scores on discharge.

CONCLUSION

The presence of HIT in SAH has adverse consequences and is more likely in female patients who have undergone aneurysm clipping and require multiple endovascular vasospasm treatments.

Guidelines for the management of aneurysmal subarachnoid hemorrhage: a guideline for healthcare professionals from the American Heart Association/american Stroke Association

PURPOSE

The aim of this guideline is to present current and comprehensive recommendations for the diagnosis and treatment of aneurysmal subarachnoid hemorrhage (aSAH).

METHODS

A formal literature search of MEDLINE (November 1, 2006, through May 1, 2010) was performed. Data were synthesized with the use of evidence tables. Writing group members met by teleconference to discuss data-derived recommendations. The American Heart Association Stroke Council's Levels of Evidence grading algorithm was used to grade each recommendation. The guideline draft was reviewed by 7 expert peer reviewers and by the members of the Stroke Council Leadership and Manuscript Oversight Committees. It is intended that this guideline be fully updated every 3 years.

RESULTS

Evidence-based guidelines are presented for the care of patients presenting with aSAH. The focus of the guideline was subdivided into incidence, risk factors, prevention, natural history and outcome, diagnosis, prevention of rebleeding, surgical and endovascular repair of ruptured aneurysms, systems of care, anesthetic management during repair, management of vasospasm and delayed cerebral ischemia, management of hydrocephalus, management of seizures, and management of medical complications.

CONCLUSIONS

aSAH is a serious medical condition in which outcome can be dramatically impacted by early, aggressive, expert care. The guidelines offer a framework for goal-directed treatment of the patient with aSAH.

Deep venous thrombosis prophylaxis

Although clinicians are generally advised to use prophylactic therapy to reduce the risk for developing deep venous thrombosis in patients after repair of ruptured aneurysms, limited data are available to guide specific therapeutic decisions. An electronic literature search was conducted to identify English-language articles that addressed prophylactic treatment for deep venous thrombosis after subarachnoid hemorrhage published between 1980 and March 2011. A total of 12 articles were included in this review, including seven original research studies and one meta-analysis. The incidence of deep venous thrombosis varied among studies, with the highest incidence reported with prospective ultrasound screening. Poor-grade patients are at highest risk. Mechanical prophylactic methods appear to be modestly effective as monotherapy, without significant risk for the typical patient with subarachnoid hemorrhage. Unfractionated heparin is moderately effective but carries a small risk of intracranial hemorrhage. Low molecular weight heparin has been linked to an increased risk for intracranial hemorrhage. Limited data are available to direct the timing and duration of prophylactic therapies.

Risk Factors for Heparin-Induced Thrombocytopenia Type II in Aneurysmal Subarachnoid Hemorrhage

BACKGROUND

Heparin-induced thrombocytopenia type II (HIT II) correlates with a higher incidence of thromboembolic complications and unfavorable outcome.

OBJECTIVE

To examine the risk factors and outcomes for patients with HIT II with aneurysmal subarachnoid hemorrhage.

METHODS

Demographics, risk factors, treatments, and outcomes data of 600 aneurysmal subarachnoid hemorrhage patients admitted to the University of Illinois Medical Center in Chicago between June 2002 and July 2007 were retrospectively reviewed. Patients meeting the clinical criteria for HIT II were compared with those who did not develop thrombocytopenia.

RESULTS

Twenty-five patients (6%) met the clinical criteria for HIT II, and 396 (94%) did not develop thrombocytopenia. Both groups were the same with respect to age, Hunt-Hess score and Fisher grade on admission, medical conditions, and social risk factors. The HIT II patients had significantly more unfavorable outcomes (modified Rankin Scale score &gt;3), deep vein thrombosis, stroke, pulmonary embolism, and death. Development of HIT II was strongly associated with symptomatic vasospasm (odds ratio, 5.7; 95% confidence interval, 2.5-13.1; P &lt; .001) and number of angiographic procedures (odds ratio, 1.7; 95% confidence interval, 1.3-2.2; P &lt; .001). Forward buildup selection modeling demonstrated the latter to be the strongest predictor for HIT II development (odds ratio, 2.3; 95% confidence interval, 1.7-3.2; P = .02).

CONCLUSION

Heparin-induced thrombocytopenia type II correlates with a worse outcome and higher risk of thromboembolic complications in aneurysmal subarachnoid hemorrhage patients. In addition, HIT II was strongly associated with the number of angiographic procedures performed during the same hospitalization.