Pui Man Rosalind Lai

Aspirin and Aneurysmal Subarachnoid Hemorrhage

OBJECTIVEnRecent evidence has suggested a potential beneficial effect of aspirin on the risk of aneurysm rupture. This benefit must be weighed against its potential adverse effects as an antiplatelet agent in the setting of acute aneurysmal subarachnoid hemorrhage (SAH).nnnMETHODSnA total of 747 consecutive patients with cerebral aneurysms were reviewed, comparing demographics, aneurysm features, presenting clinical and radiographic grades, vasospasm, and outcome at 1 year between patients with aneurysmal SAH taking aspirin on presentation and those who were not.nnnRESULTSnThe rate of hemorrhagic presentation was significantly greater in patients not taking aspirin (40% vs. 28%; P = 0.016). Among 274 patients presenting with aneurysmal SAH, there was no significant difference in presenting clinical (Hunt and Hess) and radiographic (Fisher) grade between patients taking aspirin and those who were not. There was also no significant difference in the rate of subsequent angiographic and delayed cerebral ischemia. Multivariate analysis of outcome at 1 year found only increasing age (odds ratio [OR] 1.07, 95% confidence interval [CI] 1.04-1.12), Hunt and Hess grade (OR 3.01, 95% CI 1.81-5.03), and associated hypertension (OR 3.30, 95% CI 1.39-7.81) to be statistically significant risk factors for poor outcome (death or dependence), whereas aspirin use was not associated with poor outcome (OR 1.19, 95% CI 0.35-4.09; P = 0.78).nnnCONCLUSIONSnIn the present study, patients taking aspirin had a lower rate of hemorrhagic presentation. In addition, taking aspirin did not adversely impact presenting clinical grade or radiographic grade, vasospasm, and outcome in the setting of aneurysmal SAH.

Neurogenic Stress Cardiomyopathy After Aneurysmal Subarachnoid Hemorrhage

BACKGROUNDnNeurogenic stress cardiomyopathy (NSC) is a known complication of aneurysmal subarachnoid hemorrhage (SAH). Detailed analyses of risk factors for its occurrence across large cohorts are relatively sparse.nnnMETHODSnA consecutive group of 300 patients with aneurysmal SAH was reviewed for the presence of markers of myocardial injury, including electrocardiogram changes (long QT, T-wave inversion), elevated plasma troponin levels (≥0.1), and echocardiogram findings (decreased ejection fraction and wall motion abnormalities). NSC was defined as the presence of at least 1 marker of myocardial injury. Univariate and multivariate analyses were conducted to assess the correlation of NSC and individual markers of myocardial injury with age, gender, medical comorbidities, medications, current smoking status, Hunt-Hess grade, and Fisher grade. Medical comorbidities were assessed based on reported medical history or reported use of comorbidity-specific medications at the time of presentation.nnnRESULTSnAcross the cohort, 27% of patients had a plasma troponin elevation of at least 0.1; 13%, a prolonged QT interval; 16%, new T-wave inversions; 18%, a depressed ejection fraction (<55%); and 15%, echocardiographic wall motion abnormalities. After a multivariate analysis, significant risk factors for NSC included higher Hunt-Hess grade on presentation (odds ratio [OR] = 2.33, P = 4.52 × 10(-6)), current smoking status (OR = 2.00, P = 0.030), and older age (OR = 1.03, P = 0.048). Hypertension was protective against NSC (OR = 0.48, P = 0.031). Patient gender, hyperlipidemia, diabetes, coronary artery disease, statin use, beta blocker use, angiotensin-converting enzyme inhibitor use, aspirin use, and thicker SAH (Fisher grade 3) were not significant risk factors for NSC.nnnCONCLUSIONSnHigher Hunt-Hess grade, current smoking status, lack of hypertension, and older age were the strongest predictors of NSC.

Treatment Modality and Vasospasm After Aneurysmal Subarachnoid Hemorrhage

OBJECTIVEnVasospasm is the leading source of neurological morbidity after aneurysmal subarachnoid hemorrhage. Our objective was to evaluate the impact of treatment modality on vasospasm, delayed cerebral infarction, and clinical deterioration caused by delayed cerebral ischemia (CD-DCI).nnnMETHODSnWe reviewed an institutional cohort, comparing rates of vasospasm, delayed cerebral infarction, and CD-DCI between patients managed with only microsurgical clipping and those treated with only endovascular coiling within 72 hours of rupture. Age, sex, smoking status, Hunt-Hess grade, and Fisher grade were adjusted for in a multivariate regression model.nnnRESULTSnTwo hundred three patients were treated with clipping and 52 with coiling. There was no significant difference in patient age, sex, smoking status, aneurysm location, and presenting clinical (Hunt-Hess) and radiographic (Fisher) grade between these two groups. Sixty-percent of patients had moderate or severe vasospasm after clipping compared with 38% after coiling (Multivariate odds ratio [OR] 2.32, 95% confidence interval [95% CI] 1.21-4.47, P = 0.01). Clipping was associated with a greater number of territories with vasospasm (mean of 3.1 vs. 2.3, P = 0.03 after multivariate analysis). Delayed radiographic cerebral infarction was more common in the clipping group (17% vs. 6%, multivariate OR 3.66, 95% CI 1.06-12.71, P = 0.04). For CD-DCI, a trend was seen as 16% of patients treated with clipping had CD-DCI compared with 6% of patients treated with coiling (multivariate OR 3.11, 95% CI 0.89-10.86, P = 0.07).nnnCONCLUSIONnWe demonstrate significantly lower rates of vasospasm and delayed infarction after endovascular coiling of ruptured aneurysms.

Association between S100B Levels and Long-Term Outcome after Aneurysmal Subarachnoid Hemorrhage: Systematic Review and Pooled Analysis

S100 calcium binding protein B (S100B), a well-studied marker for neurologic injury, has been suggested as a candidate for predicting outcome after subarachnoid hemorrhage. We performed a pooled analysis summarizing the associations between S100B protein in serum and cerebrospinal fluid (CSF) with radiographic vasospasm, delayed ischemic neurologic deficit (DIND), delayed cerebral infarction, and Glasgow Outcome Scale (GOS) outcome. A literature search using PubMed, the Cochrane Library, and the EMBASE databases was performed to identify relevant studies published up to May 2015. The weighted Stouffer’s Z method was used to perform a pooled analysis of outcome measures with greater than three studies. A total of 13 studies were included in this review. Higher serum S100B level was found to be associated with cerebral infarction as diagnosed by CT (padj = 3.1 x 10−4) and worse GOS outcome (padj = 5.5 x 10−11). There was no association found between serum and CSF S100B with radiographic vasospasm or DIND. S100B is a potential prognostic marker for aSAH outcome.

The impact of insurance status on the outcomes after aneurysmal subarachnoid hemorrhage.

Investigation into the association of insurance status with the outcomes of patients undergoing neurosurgical intervention has been limited: this is the first nationwide study to analyze the impact of primary payer on the outcomes of patients with aneurysmal subarachnoid hemorrhage who underwent endovascular coiling or microsurgical clipping. The Nationwide Inpatient Sample (2001–2010) was utilized to identify patients; those with both an ICD-9 diagnosis codes for subarachnoid hemorrhage and a procedure code for aneurysm repair (either via an endovascular or surgical approach) were included. Hierarchical multivariate regression analyses were utilized to evaluate the impact of primary payer on in-hospital mortality, hospital discharge disposition, and length of hospital stay with hospital as the random effects variable. Models were adjusted for patient age, sex, race, comorbidities, socioeconomic status, hospital region, location (urban versus rural), and teaching status, procedural volume, year of admission, and the proportion of patients who underwent ventriculostomy. Subsequent models were also adjusted for time to aneurysm repair and time to ventriculostomy; subgroup analyses evaluated for those who underwent endovascular and surgical procedures separately. 15,557 hospitalizations were included. In the initial model, the adjusted odds of in-hospital mortality were higher for Medicare (OR 1.23, p<0.001), Medicaid (OR 1.23, p<0.001), and uninsured patients (OR 1.49, p<0.001) compared to those with private insurance. After also adjusting for timing of intervention, Medicaid and uninsured patients had a reduced odds of non-routine discharge (OR 0.75, p<0.001 and OR 0.42, p<0.001) despite longer hospital stays (by 8.35 days, p<0.001 and 2.45 days, pu200a=u200a0.005). Variations in outcomes by primary payer–including in-hospital post-procedural mortality–were more pronounced for patients of all insurance types who underwent microsurgical clipping. The observed differences by primary payer are likely multifactorial, attributable to varied socioeconomic factors and the complexities of the American healthcare delivery system.

The Association between Meteorological Parameters and Aneurysmal Subarachnoid Hemorrhage: A Nationwide Analysis

Prior research has suggested that regional weather patterns impact the risk of rupture of cerebral aneurysms, but the findings in the literature have been inconsistent. Furthermore, no nationwide analysis to date has examined the association between meteorological factors and the post-procedural outcomes of patients after the treatment for ruptured cerebral aneurysms. The purpose of this study was to use a nationwide sample to analyze the association between specific meteorological parameters—temperature, precipitation, sunlight, and humidity—and hospital admission rate for and outcome after aneurysmal subarachnoid hemorrhage. Patients were identified using the Nationwide Inpatient Sample (2001–2010): Those with an ICD-9 diagnosis code for subarachnoid hemorrhage and a procedural code for aneurysm repair were included. Climate data were obtained from the State of the Climate Report 2010 released by the National Climatic Data Center. Multivariate regression models were constructed to analyze the association between average state monthly temperature, precipitation, and percent possible sunlight, as well as relative morning humidity and both monthly hospital admission rate, adjusted for annual state population in millions, and in-hospital mortality. 16,970 admissions were included from 723 hospitals across 41 states. Decreased daily sunlight and lower relative humidity were associated with an increased rate of admission for ruptured cerebral aneurysms (p<0.001), but had no association with differential inpatient mortality. No significant changes in these observed associations were seen when multivariate analyses were constructed. This is the first nationwide study to suggest that decreased sunlight and lower relative humidity are associated with admission for ruptured cerebral aneurysms. While it has been postulated that external atmospheric factors may cause hormonal and homeostatic changes that impact the risk of rupture of cerebral aneurysms, additional research is needed to confirm and further understand these relationships.

Effect of teaching hospital status on outcome of aneurysm treatment.

OBJECTIVEnThere is increasing literature supporting the importance in triaging patients to teaching hospitals for complex surgical procedures. This study analyzes the effect of teaching hospital status on outcome of endovascular coiling and microsurgical clipping of ruptured and unruptured intracranial aneurysms using the Nationwide Inpatient Sample database.nnnMETHODSnWe analyzed patients with cerebral aneurysms using the Nationwide Inpatient Sample 2001 to 2010. Patients with ruptured aneurysms were identified by International Classification of Diseases, 9th revision codes for diagnoses of subarachnoid hemorrhage or intracerebral hemorrhage and at least one procedural code for aneurysm repair. Patients with unruptured cerebral aneurysms were identified by diagnosis code 437.3 and at least one procedural code. Multivariate linear models were used to analyze the association of in-hospital death, nonroutine discharge, and length of stay with teaching hospital status, adjusting for patient age, sex, race, comorbidities, household income, time to aneurysm repair procedure, aneurysm procedure volume, hospital region, and location.nnnRESULTSnThere were 34,843 hospitalizations for treatments of unruptured (14,763 in teaching and 1794 in nonteaching hospitals) and ruptured (15,628 in teaching and 2658 in nonteaching hospitals) aneurysms. In patients with ruptured aneurysms, the odds ratio of in-hospital death and nonroutine discharges were 0.69 (95% confidence interval 0.54-0.88) and 0.77 (95% confidence interval 0.60-0.99) in teaching hospitals, respectively, independent of hospital aneurysm procedure volume.nnnCONCLUSIONSnOur results suggest that the teaching status of a hospital is an independent factor for favorable outcome in the treatment of ruptured aneurysms. The difference in in-hospital death is accentuated in patients who underwent microsurgical clipping.

Hydrocephalus after arteriovenous malformation rupture

OBJECTnThe rates and risk factors for external ventricular drain (EVD) placement and long-term shunt dependence in patients with ruptured arteriovenous malformations (AVMs) have not been systematically studied. In this study the authors evaluated the rates of EVD placement and shunt dependence, and risk factors for them, in a cohort of patients with ruptured AVMs.nnnMETHODSnThe records of 87 consecutive patients with ruptured AVMs were reviewed for patient demographics, hemorrhage pattern, AVM angioarchitectural features, and surgical treatment. Univariate and multivariate logistic regression analyses were performed to evaluate risk factors for EVD placement, permanent shunt dependence, and long-term outcome (as measured by the modified Rankin Scale).nnnRESULTSnThirty-eight patients (44%) required EVD placement, and 16 (18%) required a permanent shunt. Statistically significant risk factors for EVD placement in the univariate analysis included initial Glasgow Coma Scale (GCS) score (p = 0.002), the presence of intraventricular hemorrhage (IVH; p < 0.001), AVM-associated aneurysms (p = 0.002), and early surgery (p = 0.01). Multivariate analysis revealed only AVM-associated aneurysms as statistically significant (p = 0.006). Risk factors for shunt placement included initial GCS score (p = 0.003), IVH (p = 0.01), deep supratentorial location (p = 0.034), and associated aneurysms (p = 0.03). Multivariate analysis revealed initial GCS score as a statistically significant risk factor (p = 0.041) as well as a strong trend for associated aneurysms (p = 0.06). Patient age, sex, associated subarachnoid hemorrhage, AVM grade, AVM size, and deep venous drainage were not associated with EVD placement or long-term shunt dependence.nnnCONCLUSIONSnHydrocephalus from AVM rupture was associated with initial GCS score, IVH, and AVM-associated aneurysms. Arteriovenous malformations with associated aneurysms thus not only have a greater risk of hemorrhage but also a greater risk of hemorrhage-associated morbidity as a result of hydrocephalus.

Risk factors for hyponatremia in aneurysmal subarachnoid hemorrhage

Hyponatremia occurs commonly in patients with aneurysmal subarachnoid hemorrhage (aSAH). Our objective was to determine the time course of, and factors associated with, hyponatremia after aSAH. We performed a retrospective review of 259 patients with ruptured aneurysms at a single institution. Multivariate regression analysis was performed to determine the factors associated with hyponatremia. Increasing age was significantly associated with lower initial sodium (p=0.04) and incidence of delayed hyponatremia (p=0.01) while smoking was associated with longer duration of hyponatremia (p=0.02). Older patients should therefore be monitored closely for hyponatremia and patients who smoke should be treated more aggressively for hyponatremia given the greater frequency and longer duration of hyponatremia in these two groups, respectively.

Impact of aneurysm location on hemorrhage risk

INTRODUCTIONnRecent studies have reinforced anterior communicating (AComm) artery location as a significant risk factor for aneurysm rupture in addition to posterior circulation/posterior communicating (PComm) artery location. However, studies stratifying aneurysm location in greater detail are sparse.nnnMETHODSnWe reviewed the records of 747 consecutive patients with 1013 aneurysms seen at our institution over a 7 year period, noting aneurysm location and rupture status at the time of presentation.nnnRESULTSnHigh proportions of ruptured aneurysms were seen among frontopolar/pericallosal (59%, OR 3.07, p=0.011), vertebral/posteroinferior cerebellar (PICA; 53%, OR 2.49, p=0.0037), AComm (50%, OR 2.46, p<0.0001), and PComm aneurysms (44%, OR 1.77, p=0.0016). Low proportions of ruptured aneurysms were seen among superior hypophyseal artery (SHA; 6%, OR 0.12, p=0.0001), internal carotid artery (ICA) bifurcation (12%, OR 0.27, p=0.0012), and ophthalmic artery aneurysms (15%, OR 0.33, p=0.0002). The proportion of ruptured PComm aneurysms demonstrated a trend toward being greater than anterior choroidal artery aneurysms (OR 2.14, p=0.09); however the proportion was significantly greater among anterior choroidal artery aneurysms as compared to nonPComm intradural ICA aneurysms (OR 2.78, p=0.03). Notably, the lower rupture rate of SHA aneurysms as compared to ophthalmic artery aneurysms neared statistical significance (OR 0.38, p=0.10).nnnCONCLUSIONnAneurysm location has a significant impact on risk of rupture and should be stratified in greater detail in future studies of aneurysm natural history.