Low-Dose versus Therapeutic Range Intravenous Unfractionated Heparin Prophylaxis in the Treatment of Patients with Severe Aneurysmal Subarachnoid Hemorrhage After Aneurysm Occlusion

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.

Association between external ventricular drain removal or replacement and prophylactic anticoagulation in patients with aneurysmal subarachnoid hemorrhage: a propensity-adjusted analysis

BACKGROUND

Withholding prophylactic anticoagulation from patients with aneurysmal subarachnoid hemorrhage (aSAH) before external ventricular drain (EVD) removal or replacement remains controversial. This study analyzed whether prophylactic anticoagulation was associated with hemorrhagic complications related to EVD removal.

METHOD

All aSAH patients treated from January 1, 2014, to July 31, 2019, with an EVD placed were retrospectively analyzed. Patients were compared based on the number of prophylactic anticoagulant doses withheld for EVD removal (> 1 vs. ≤ 1). The primary outcome analyzed was deep venous thrombosis (DVT) or pulmonary embolism (PE) after EVD removal. A propensity-adjusted logistic-regression analysis was performed for confounding variables.

RESULTS

A total of 271 patients were analyzed. For EVD removal, > 1 dose was withheld from 116 (42.8%) patients. Six (2.2%) patients had a hemorrhage associated with EVD removal, and 17 (6.3%) patients had a DVT or PE. No significant difference in EVD-related hemorrhage after EVD removal was found between patients with  > 1 versus ≤ 1 dose of anticoagulant withheld (4 of 116 [3.5%] vs. 2 of 155 [1.3%]; p = 0.41) or between those with no doses withheld compared to ≥ 1 dose withheld (1 of 100 [1.0%] vs. 5 of 171 [2.9%]; p = 0.32). After adjustment, withholding > 1 dose of anticoagulant versus ≤ 1 dose was associated with the occurrence of DVT or PE (OR 4.8; 95% CI, 1.5-15.7; p = 0.009).

CONCLUSIONS

In aSAH patients with EVDs, withholding > 1 dose of prophylactic anticoagulant for EVD removal was associated with an increased risk of DVT or PE and no reduction in catheter removal-associated hemorrhage.

Characterizing Risk of In-Hospital Mortality Following Subarachnoid Hemorrhage Using Machine Learning: A Retrospective Study

Background

Subarachnoid hemorrhage has a high rate of disability and mortality, and the ability to use existing disease severity scores to estimate the risk of adverse outcomes is limited. Collect relevant information of patients during hospitalization to develop more accurate risk prediction models, using logistic regression (LR) and machine learning (ML) technologies, combined with biochemical information.

Methods

Patient-level data were extracted from MIMIC-IV data. The primary outcome was in-hospital mortality. The models were trained and tested on a data set (ratio 70:30) including age and key past medical history. The recursive feature elimination (RFE) algorithm was used to screen the characteristic variables; then, the ML algorithm was used to analyze and establish the prediction model, and the validation set was used to further verify the effectiveness of the model.

Result

Of the 1,787 patients included in the mimic database, a total of 379 died during hospitalization. Recursive feature abstraction (RFE) selected 20 variables. After simplification, we determined 10 features, including the Glasgow coma score (GCS), glucose, sodium, chloride, SPO₂, bicarbonate, temperature, white blood cell (WBC), heparin use, and sepsis-related organ failure assessment (SOFA) score. The validation set and Delong test showed that the simplified RF model has a high AUC of 0.949, which is not significantly different from the best model. Furthermore, in the DCA curve, the simplified GBM model has relatively higher net benefits. In the subgroup analysis of non-traumatic subarachnoid hemorrhage, the simplified GBM model has a high AUC of 0.955 and relatively higher net benefits.

Conclusions

ML approaches significantly enhance predictive discrimination for mortality following subarachnoid hemorrhage compared to existing illness severity scores and LR. The discriminative ability of these ML models requires validation in external cohorts to establish generalizability.

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.

Heparin in the treatment of aneurysmal subarachnoid hemorrhage: a systematic review and meta-analysis

OBJECTIVE

Cerebral vasospasm and the resulting infarction remain the most devastating complications of aneurysmal subarachnoid hemorrhage (aSAH). Limited treatment options are available, with nimodipine as the only approved prophylactic medication. In addition to its anticoagulant properties, heparin also has a pleiotropic and anti-inflammatory effect that could be beneficial in vasospasm. In this study, the authors sought to evaluate the efficacy and safety of heparin in the treatment of aSAH.

METHODS

The PubMed, EBSCOhost, Europe PMC, and Cochrane Central databases were searched to find studies including patients with aSAH who were treated with intravenous unfractionated heparin (UFH) after an aneurysm-securing procedure. Studies that did not include a comparison with UFH or low-molecular-weight heparin in deep vein thrombosis prophylactic doses were excluded. The primary outcome was cerebral vasospasm, and the secondary outcomes were cerebral infarction, clinical deterioration caused by delayed cerebral ischemia, bleeding complications, and thromboembolism complications.

RESULTS

Overall, 5 nonrandomized studies were included; 4 studies evaluated the safety and 3 studies evaluated the efficacy of intravenous heparin. From the analysis of 3 studies with a total of 895 patients, administration of intravenous UFH for > 48 hours was related to a significantly lower rate of cerebral infarction (OR 0.44, 95% CI 0.25–0.79). No significant association was found with other efficacy outcomes. Regarding cognitive outcome, one study found a significant improvement in Montreal Cognitive Assessment scores; however, the functional outcome as indicated by the modified Rankin Scale score was not improved by heparin administration. From the analysis of 4 studies with 1099 patients, no significant increases in bleeding and other complications were found.

CONCLUSIONS

Administration of intravenous UFH for more than 48 hours reduced the rate of cerebral infarction with a good safety profile. This result supports the ongoing clinical trial.

Multidisciplinary Bundle Approach in Venous Thromboembolism Prophylaxis in Patients with Non-Traumatic Subarachnoid Hemorrhage

Background

A venous thromboembolism (VTE) bundle was launched in 2016 at the University of Illinois Hospital aiming to reduce the rate of VTE in the neurosurgical ICU. Main elements of the bundle included correct and early use of intermittent pneumatic compression and subcutaneous heparin.

Methods

Patients with SAH were retrospectively identified from 2014 until 2018. VTE events were diagnosed using twice weekly lower-extremity venous Duplex ultrasound and chest computerized tomography when appropriate.

Results

A total of 133 patients was included in each group. The incidence of VTE was not significantly different before and after the bundle (15% vs. 12%, p = 0.47). No difference was found regarding new episode of intracranial hemorrhage secondary to SQH (1.5% vs. 2.1%, p = 0.65). Multivariate analysis demonstrated that longer ICU LOS, higher Caprini score, and presence of baseline lung diseases were associated with VTE development.

Conclusions

With a median Caprini score of 9, our patient population was found to be at high risk for developing VTE. The implementation of the VTE bundle did not significantly reduce the rate of VTE in patients with non-traumatic SAH at UIH.

Early prophylactic anticoagulation after subarachnoid hemorrhage decreases systemic ischemia and improves outcome

BACKGROUND

In neurosurgical perioperative treatment, especially in connection with subarachnoid hemorrhage (SAH), the prophylactic anticoagulation (AC) regimen is still considered controversial. The goal of this retrospective study was to assess how the time point of low-molecular-weight heparin (LMWH) initiation (ToH) affects ischemic and hemorrhagic events after SAH.

METHODS

370 patients who received acute treatment for non-traumatic SAH between 2011 and 2018 were included, and 208 patients were followed up after 12 months. We assessed how the ToH affects ischemic and hemorrhagic events as well as outcome scores. Statistical analysis was performed using the Mann-Whitney U-Test, the chi-squared test, Fisher's exact test, and univariate binomial logistic regression. P-values below 0.05 were considered statistically significant.

RESULTS

The incidence of systemic ischemia was 4.6%, cerebral ischemia 33.5%, and intracranial rebleeding 14.6%. Delaying ToH (measured in hours) increases systemic ischemia (p = 0.009). The odds ratio for the impact of delayed anticoagulation on systemic ischemia is 1.013 per hour (95%CI of OR 1.001-1.024). ToH has no influence on cerebral ischemia or intracranial rebleeding. Early anticoagulation was associated with a more favorable Glasgow Outcome Score 12 months after discharge (ToH within 48 h: p = 0.006). ToH did not affect mortality or readmission rates.

CONCLUSIONS

Initiating prophylactic AC with LMWH later than 48 h after aneurysm repair or admission impairs outcomes 12 months after discharge. It might be safe for patients with non-traumatic SAH to be anticoagulated with prophylactic doses of heparin within 24 h after admission or the treatment of source of bleeding (SoB). Early AC with prophylactic LMWH does not promote rebleeding.

Low-Dose Intravenous Heparin Infusion After Aneurysmal Subarachnoid Hemorrhage is Associated With Decreased Risk of Delayed Neurological Deficit and Cerebral Infarction

BACKGROUND

Patients who survive aneurysmal subarachnoid hemorrhage (aSAH) are at risk for delayed neurological deficits (DND) and cerebral infarction. In this exploratory cohort comparison analysis, we compared in-hospital outcomes of aSAH patients administered a low-dose intravenous heparin (LDIVH) infusion (12 U/kg/h) vs those administered standard subcutaneous heparin (SQH) prophylaxis for deep vein thrombosis (DVT; 5000 U, 3 × daily).

OBJECTIVE

To assess the safety and efficacy of LDIVH in aSAH patients.

METHODS

We retrospectively analyzed 556 consecutive cases of aSAH patients whose aneurysm was secured by clipping or coiling at a single institution over a 10-yr period, including 233 administered the LDIVH protocol and 323 administered the SQH protocol. Radiological and outcome data were compared between the 2 cohorts using multivariable logistic regression and propensity score-based inverse probability of treatment weighting (IPTW).

RESULTS

The unadjusted rate of cerebral infarction in the LDIVH cohort was half that in SQH cohort (9 vs 18%; P = .004). Multivariable logistic regression showed that patients in the LDIVH cohort were significantly less likely than those in the SQH cohort to have DND (odds ratio (OR) 0.53 [95% CI: 0.33, 0.85]) or cerebral infarction (OR 0.40 [95% CI: 0.23, 0.71]). Analysis following IPTW showed similar results. Rates of hemorrhagic complications, heparin-induced thrombocytopenia and DVT were not different between cohorts.

CONCLUSION

This cohort comparison analysis suggests that LDIVH infusion may favorably influence the outcome of patients after aSAH. Prospective studies are required to further assess the benefit of LDIVH infusion in patients with aSAH.