Incidence Of Aneurysmal Subarachnoid Hemorrhage Research Articles

Prescribed Drug Use and Aneurysmal Subarachnoid Hemorrhage Incidence: A Drug-Wide Association Study.

Current benefits of invasive intracranial aneurysm treatment to prevent aneurysmal subarachnoid hemorrhage (aSAH) rarely outweigh treatment risks. Most intracranial aneurysms thus remain untreated. Commonly prescribed drugs reducing aSAH incidence may provide leads for drug repurposing. We performed a drug-wide association study (DWAS) to systematically investigate the association between commonly prescribed drugs and aSAH incidence. We defined all aSAH cases between 2000 and 2020 using International Classification of Diseases codes from the Secure Anonymised Information Linkage databank. Each case was matched with 9 controls based on age, sex, and year of database entry. We investigated commonly prescribed drugs (>2% in study population) and defined 3 exposure windows relative to the most recent prescription before index date (i.e., occurrence of aSAH): current (within 3 months), recent (3-12 months), and past (>12 months). A logistic regression model was fitted to compare drug use across these exposure windows vs never use, controlling for age, sex, known aSAH risk factors, and health care utilization. The family-wise error rate was kept at p < 0.05 through Bonferroni correction. We investigated exposure to 205 commonly prescribed drugs between 4,879 aSAH cases (mean age 61.4, 61.2% women) and 43,911 matched controls. We found similar trends for lisinopril and amlodipine, with a decreased aSAH risk for current use (lisinopril odds ratio [OR] 0.63, 95% CI 0.44-0.90, amlodipine OR 0.82, 95% CI 0.65-1.04) and an increased aSAH risk for recent use (lisinopril OR 1.30, 95% CI 0.61-2.78, amlodipine OR 1.61, 95% CI 1.04-2.48). A decreased aSAH risk in current use was also found for simvastatin (OR 0.78, 95% CI 0.64-0.96), metformin (OR 0.58, 95% CI 0.43-0.78), and tamsulosin (OR 0.55, 95% CI 0.32-0.93). By contrast, an increased aSAH risk was found for current use of warfarin (OR 1.35, 95% CI 1.02-1.79), venlafaxine (OR 1.67, 95% CI 1.01-2.75), prochlorperazine (OR 2.15, 95% CI 1.45-3.18), and co-codamol (OR 1.31, 95% CI 1.10-1.56). We identified several drugs associated with aSAH, of which 5 drugs (lisinopril and possibly amlodipine, simvastatin, metformin, and tamsulosin) showed a decreased aSAH risk. Future research should build on these signals to further assess the effectiveness of these drugs in reducing aSAH incidence. This study provides Class III evidence that some commonly prescribed drugs are associated with subsequent development of aSAH.

Sex differences in risk factor relationships with subarachnoid haemorrhage and intracranial aneurysms: A Mendelian Randomisation study.

The prevalence of intracranial aneurysms (IAs) and incidence of aneurysmal subarachnoid haemorrhage (aSAH) is higher in women than in men. Although several cardiometabolic and lifestyle factors have been related to the risk of IAs or aSAH, it is unclear whether there are sex differences in causal relationships of these risk factors. The aim of this study was to determine sex differences in causal relationships between cardiometabolic and lifestyle factors and risk of aSAH and IA. We conducted a sex-specific two-sample Mendelian randomisation study using summary-level data from genome-wide association studies. We analysed low-density lipoprotein cholesterol, high-density lipoprotein cholesterol [HDL-C], triglycerides, non-HDL-C, total cholesterol, fasting glucose, systolic and diastolic blood pressure, smoking initiation, and alcohol use as exposures, and aSAH and IA (i.e., aSAH and unruptured IA combined) as outcomes. We found statistically significant sex differences in the relationship between genetically proxied non-HDL-C and aSAH risk, with odds ratios (ORs) of 0.72 (95% confidence interval 0.58, 0.88) in women and 1.01 (0.77, 1.31) in men (P-value for sex difference 0.044). Moreover, genetic liability to smoking initiation was related to a statistically significantly higher risk of aSAH in men compared to women (P-value for sex difference 0.007) with ORs of 3.81 (1.93, 7.52) and 1.12 (0.63, 1.99), respectively, and to a statistically significantly higher IA risk in men compared to women (P-value for sex difference 0.036) with ORs of 3.58 (2.04, 6.27) and 1.61 (0.98, 2.64), respectively. In addition, higher genetically proxied systolic and diastolic blood pressure were related to a higher risk of aSAH and IA in both women and men. Higher genetically proxied non-HDL-C was related to a lower risk of aSAH in women compared to men. Moreover, genetic liability to smoking initiation was associated with a higher risk for aSAH and IA in men compared to women. These findings may help improve understanding of sex differences in the development of aSAH and IA.

Subarachnoid Haemorrhage Incidence Pattern Analysis with Circular Statistics.

Knowledge about biological rhythms of diseases may not only help in understanding the pathophysiology of diseases but can also help health service policy makers and emergency department directors to allocate resources efficiently. Aneurysmal subarachnoid haemorrhage (SAH) has high rates of morbidity and mortality. The incidence of SAH has been attributed to patient-related factors such as characteristics of aneurysms, smoking, and hypertension. There are studies showing that the incidence of aneurysmal SAH appears to behave in periodic fashions over long time periods. However, there are inconsistencies in the literature regarding the impact of chronobiological factors such as circadian, seasonal, and lunar cycle factors on the occurrence of SAH. In this study, we focused on the analysis of a temporal pattern of SAH (infradian rhythms) with a novel approach using circular statistical methods. We aimed to see whether there is a circular pattern for the occurrence of SAH at all and if so, whether it can be related to known temporal patterns based on available literature. Our study did not support the notion that aneurysmal subarachnoid haemorrhages occur on any specific day in a cycle with specific lengths up to 365 days including specific weekdays, full moon, equinoxes, and solstices. Hence, we found no relationship between SAH incidence and timing. Study in larger populations using similar circular statistical methods is suggested.

Analysis of aneurysmal subarachnoid hemorrhage as a multistep process.

Aneurysmal subarachnoid hemorrhage (ASAH) is a complex disease with higher incidence in women compared to men and in Japan compared to other countries. It was hypothesized that ASAH is consistent with a multistep model of disease. The following assessments were made: (1) the number of steps needed for the disease to occur and (2) whether this number may be different in female versus male and in Japanese versus non-Japanese patients. Incidence data were generated from a meta-analysis on ASAH incidence until 2017, which was supplemented with a literature search from 2017 to April 2023. Age- and sex-adjusted incidences per 10-year age groups were calculated and the logarithm of age-specific incidence against the logarithm of age was regressed with least-squares regression. In 2317 ASAH patients a linear relationship between logarithm of incidence and logarithm of age was found with a slope estimate of 3.13 (95% confidence interval 2.60-3.65), consistent with a four-step process. Similar estimates were found for female, male, Japanese and non-Japanese patients. Our results suggest that ASAH is a four-step process, also in subgroups with higher ASAH incidence. Elucidation of the exact nature of these steps can provide important clues for identification of disease mechanisms underlying ASAH.

Genetic Risk Score for Intracranial Aneurysms: Prediction of Subarachnoid Hemorrhage and Role in Clinical Heterogeneity.

Recently, common genetic risk factors for intracranial aneurysm (IA) and aneurysmal subarachnoid hemorrhage (ASAH) were found to explain a large amount of disease heritability and therefore have potential to be used for genetic risk prediction. We constructed a genetic risk score to (1) predict ASAH incidence and IA presence (combined set of unruptured IA and ASAH) and (2) assess its association with patient characteristics. A genetic risk score incorporating genetic association data for IA and 17 traits related to IA (so-called metaGRS) was created using 1161 IA cases and 407 392 controls from the UK Biobank population study. The metaGRS was validated in combination with risk factors blood pressure, sex, and smoking in 828 IA cases and 68 568 controls from the Nordic HUNT population study. Furthermore, we assessed association between the metaGRS and patient characteristics in a cohort of 5560 IA patients. Per SD increase of metaGRS, the hazard ratio for ASAH incidence was 1.34 (95% CI, 1.20-1.51) and the odds ratio for IA presence 1.09 (95% CI, 1.01-1.18). Upon including the metaGRS on top of clinical risk factors, the concordance index to predict ASAH hazard increased from 0.63 (95% CI, 0.59-0.67) to 0.65 (95% CI, 0.62-0.69), while prediction of IA presence did not improve. The metaGRS was statistically significantly associated with age at ASAH (β=-4.82×10-3 per year [95% CI, -6.49×10-3 to -3.14×10-3]; P=1.82×10-8), and location of IA at the internal carotid artery (odds ratio=0.92 [95% CI, 0.86-0.98]; P=0.0041). The metaGRS was predictive of ASAH incidence, although with limited added value over clinical risk factors. The metaGRS was not predictive of IA presence. Therefore, we do not recommend using this metaGRS in daily clinical care. Genetic risk does partly explain the clinical heterogeneity of IA warranting prioritization of clinical heterogeneity in future genetic prediction studies of IA and ASAH.

Aneurysmal subarachnoid hemorrhage in Germany between 2005 and 2018: A nationwide observational study.

In recent decades, the global incidence of aneurysmal subarachnoid hemorrhage (aSAH) has declined. However, significant regional differences exist. We present the first comprehensive analysis of time trends in the incidence of aSAH and case fatality in Germany. All patients hospitalized with aSAH in Germany between 2005 and 2018 were identified using International Classification of Disease, 10th Revision codes I60.0-I60.7. A total of 101,105 cases were included. The incidence of aSAH in Germany decreased at a mean annual rate of 0.5% (p= 0.003) from 8.9 per 100,000 population in 2005 to 8.2 in 2018. Over time, incidences of aSAH declined among patients younger than 55 years and patients aged 70-79 years, increased among ages 60-64 years, and remained stable in age groups 65-69 and 85-89 years. This corresponded to an increase in the mean age of aSAH onset from 55.6 (±14.3) to 59.0 (±14.0) years. Throughout the study period, the mean age of aSAH onset was higher in women compared to men (58.3± 14.4 years vs. 56.1± 14.1 years). There were no changes in in-hospital case fatality (16.2 vs. 16.6%, p= 0.18), but the duration of hospital stay increased significantly from 19.7 to 24.8 days (p&lt; 0.001). The most frequent aSAH-associated aneurysm location was the anterior circulation throughout the entire study period. In Germany, the incidence of aSAH decreased between 2005 and 2018, especially in younger parts of the population. This may reflect effects of lifestyle adjustments most pronounced in younger age groups.

Prevalence of unruptured intracranial aneurysms: impact of different definitions – the Tromsø Study

BackgroundManagement of incidental unruptured intracranial aneurysms (UIAs) remains challenging and depends on their risk of rupture, estimated from the assumed prevalence of aneurysms and the incidence of aneurysmal subarachnoid haemorrhage....

Reader Response: Substantial Within-Country Variation in the Incidence of Subarachnoid Hemorrhage: A Nationwide Finnish Study.

In a recent article published in Neurology , Rautalin et al.1 report substantial regional differences and a decreasing trend in the incidence of aneurysmal subarachnoid hemorrhage (aSAH) in all regions of Finland. However, in Tampere University Hospital, one of the referral centers for the population in this article, we do not see the decreasing trend in the number of admitted aSAH cases, but rather a constant variation from 1990 to 2014.2

Association of Reproductive Life Span and Age at Menopause With the Risk of Aneurysmal Subarachnoid Hemorrhage.

Subarachnoid hemorrhage from cerebral aneurysm remains a devastating disease with high mortality and morbidity. Cerebral aneurysm and its rupture are more prevalent in postmenopausal women and have been postulated to be hormonally influenced. The goal of this study was to investigate the associations of female-specific factors, including reproductive life span, age at menarche, and age at menopause, with the incidence of aneurysmal subarachnoid hemorrhage (aSAH) in women. Participants in the Nurses' Health Study were followed up from 1980 or the time of reaching menopause until 2018. Only women with natural menopause or surgical menopause due to bilateral oophorectomy were included. Reproductive life span was defined by subtracting the age at menarche from the age at menopause. Multivariable-stratified proportional hazards models were used to study reproductive life span, age at menarche, and age at menopause with the incidence of aSAH. Multivariable models were adjusted for age, race, smoking, hysterectomy, hypertension, hyperlipidemia, body mass index, hormone therapy use, oral contraceptive use, and parity. A total of 97,398 postmenopausal women with reproductive life span data were included; 138 participants developed aSAH, which was confirmed on medical record review by a physician. A shorter reproductive life span (≤35 years) was associated with a 2-fold higher incidence of aSAH after multivariable adjustment (hazard ratio [HR] 2.0 [95% CI 1.4-2.8]). Early age at menopause (age <45 years) was similarly associated with a higher risk of aSAH (HR 2.1 [95% CI 1.4-3.1]), but age at menarche was not. Use of oral contraceptives and postmenopausal hormone therapy was not associated with the incidence of aSAH. An earlier age at menopause and a shorter reproductive life span duration (≤35 years) were associated with a higher risk of incident aSAH in women. No associations were noted for age at menarche, parity, oral contraceptive use, or postmenopausal therapy use.

Trends in Admissions and Outcomes for Treatment of Aneurysmal Subarachnoid Hemorrhage in the United States.

Lifestyle modifications and advances in surgical and endovascular techniques for treating unruptured intracranial aneurysm (UIA) have vastly evolved over the last few decades and may have reduced the incidence of aneurysmal subarachnoid hemorrhage (aSAH). However, the actual impact of these changes on the rates and outcomes of aSAH remain unexplored. Thus, we studied national aSAH admissions and outcome trends and changes of major risk factors over time. We queried the National Inpatient Sample between 2006 and 2018 to identify adult patients admitted and treated for UIA or ruptured aneurysm with aSAH. The Cochran-Armitage test was conducted to assess the linear trend of proportion of prevalence, inpatient mortality, hypertension, and current smoking status among aSAH admissions. Multivariable logistic regression was conducted to assess the odds of presenting with aSAH versus UIA, in addition to the odds of inpatient mortality among patients with aSAH. A total of 159,913 patients presented with UIA and 133,567 presented with aSAH. Admissions for aSAH decreased by 0.97% (p < 0.001) per year. Current smoking and hypertension were associated with higher odds of being admitted for aSAH compared with the treatment for UIA (odds ratio [OR] 1.38, 95% confidence interval [CI] 1.29-1.48; OR 1.15, 95% CI 1.08-1.22, respectively). Compared with White patients, Black patients (OR 1.32, 95% CI 1.21-1.43), Hispanic patients (OR 1.38, 95% CI 1.25-1.52), and patients of other races and/or ethnicities (OR 1.73, 95% CI 1.54-1.95) had a higher chance of presenting with aSAH. Rates of inpatient mortality among aSAH admissions showed no change over time (p = 0.21). Among patients admitted with aSAH, current smoking and hypertension showed an upward trend of 0.58% (p < 0.001) and 1.60% (p < 0.001) per year, respectively. Despite a downward trend in the annual frequency of hospitalizations for aSAH, inpatient mortality rates for patients undergoing treatment of the ruptured aneurysm have remained unchanged in the United States. Smoking and hypertension are increasingly prevalent among patients with aSAH. Thus, efforts to control these modifiable risk factors must be further strengthened.

The Times They Are a-Changin’: Increasing Complexity of Aneurysmal Subarachnoid Hemorrhages in Patients Treated from 2004 to 2018

Nationwide study results have suggested varying trends in the incidence of aneurysmal subarachnoid hemorrhage (aSAH) over time. Herein, trends over time for aSAH treated at a quaternary care center are compared with low-volume hospitals. Cases were retrospectively reviewed for patients with aSAH treated at our institution. Trend analyses were performed on the number of aSAH hospitalizations, treatment type, Charlson Comorbidity Index (CCI), Hunt and Hess grade, aneurysm location, aneurysm type, and in-hospital mortality. The National Inpatient Sample (NIS) was queried to compare the CCI scores of our patients with those of patients in low-volume hospitals (<20 aSAH/year) in our census division. Some 1248 patients (321 during 2004-2006; 927 during 2008-2018) hospitalized with aSAH were treated with endovascular therapy (489, 39%) or microsurgery (759, 61%). A significant downtrend in the annual aSAH caseload occurred (123 patients in 2004, 75 in 2018, P < 0.001). A linear uptrend was observed for the mean CCI score of patients (R2= 0.539, P < 0.001), with no change to in-hospital mortality (R2= 0.220, P= 0.24). Mean (standard deviation) CCI for small-volume hospitals treating aSAH within our division was significantly lower than that of our patient population (1.8 [1.6] vs 2.1 [2.0]) for 2012-2015. A decreasing number of patients were hospitalized with aSAH throughout the study. Compared with patients with aSAH admitted in 2004, those admitted more recently were sicker in terms of preexisting comorbidity and neurologic complexity. These trends could be attributable to the increasing availability of neurointerventional services at smaller-volume hospitals capable of treating healthier patients.

Influence of socioeconomic status on the incidence of aneurysmal subarachnoid haemorrhage and clinical recovery

BackgroundThe relevance of socioeconomic status (SES) on the incidence of aneurysmal subarachnoid haemorrhage (aSAH) and discharge functional outcomes following treatment is not clear. MethodsA retrospective cross-sectional study was performed on data retrieved from the Nationwide Hospital Morbidity Database for all aSAH cases in Australia between 2012 and 2018. Information on patient characteristics, procedures performed, discharge disposition and SES were extracted. SES data was derived from classifications by the Australian Bureau of Statistics. Putative risk factors were evaluated with univariate and multivariate logistic regression analysis to identify independent predictor of unfavourable discharge outcomes (defined as death or dependency). ResultsA total of 3,591 low SES patients (49.8%) were identified in our study cohort. Average crude incidence of aSAH was persistently higher among the SES disadvantaged (6.6 cases per 100,000 person-years, 95% CI 6.3 – 6.8), compared to the SES advantaged group (4.1 cases per 100,000 person-years, 95% CI 4.0–4.2) (p < 0.0001). Patients in the Low SES group were more likely to be active smokers, have type 2 diabetes mellitus, or live in non-metropolitan residence, and have overall worse discharge functional outcomes (27.7% versus 24.5%, p = 0.0015). Adjusting for well-established risk factors such as older age, and intracranial bleed (ICH and/or IVH), disadvantaged SES remained a significant predictor of poor discharge outcome following aSAH (p = 0.0003). ConclusionaSAH occurs more frequently among low SES communities, and once ruptured, there is a greater risk of poor recovery..

Clinical Treatment and Prognostic Analysis of Patients with Aneurysmal Subarachnoid Hemorrhage.

Subarachnoid hemorrhage (SAH) is a serious disease caused by blood flow into the subarachnoid space due to rupture of blood vessels. All diseases that cause intracranial hemorrhage are the cause of subarachnoid hemorrhage. Among them, due to the particularity of intracranial blood vessels, intracranial blood vessels are more prone to aneurysms than other parts. Therefore, the incidence of aneurysmal subarachnoid hemorrhage (aSAH) is extremely high. The purpose of this article is to study the clinical treatment and prognosis analysis of aSAH patients. This article first summarizes the current status of SAH research at home and abroad and summarizes its potential value and significance. On this basis, an in-depth study of the clinical treatment of aSAH patients has been carried out. The physiological mechanism and clinical general differences of aSAH were studied and analyzed. This article systematically describes the application of CTP in the treatment and prognosis analysis of aSAH patients. Then, it will use a comparative analysis method, interdisciplinary method, and other research forms to carry out experimental research on the theme of this article. Research shows that rebleeding and blood sodium are the main factors for cerebral ischemia caused by aSAH.

Screening of unruptured intracranial aneurysms in 50 to 60-year-old female smokers: a pilot study

The prevalence of unruptured intracranial aneurysms (UIAs) is around 2–3% in the general population. We hypothesized that the prevalence of small UIAs is higher among 50 to 60-year-old female smokers, since the incidence of aneurysmal subarachnoid hemorrhage (aSAH) is exceptionally high in 60 to 70-year-old female smokers. Ethics approval for this pilot study of 50 women was obtained from the hospital ethics committee. In order to minimize recruitment bias, preliminary invitation letters were sent to 50 to 60-year-old women who were known to be active smokers. Those interested in participating were further informed about the study rationale and protocol. Following written consent, participants filled a detailed questionnaire and underwent computed tomography angiography (CTA) analysis. All abnormalities were recorded. Of the 158 preliminary invitation letters, 70 potential participants initially replied. Of these, 50 returned questionnaires and written consents, 43 of which underwent CTA analysis. Most (39; 91%) were postmenopausal, and 9 (21%) were hypertensive. Two reported a family history (≥ 1 first-degree members) of intracranial aneurysms. UIAs (maximum sizes of 2, 2, 3, 3 and 7 mm) were found in five (12%) female smokers. One woman was operated on, and the remaining four were treated with non-invasive preventive actions (smoking cessation and follow-ups). Small UIAs, which may be best suited for non-invasive preventive actions, may be relatively common in 50 to 60-year-old female smokers. Whether this kind of targeted screening leads to improved health in female smokers requires further investigation.

Risk Factors for Cerebral Aneurysm Rupture in Mongolia

PurposeIdentification of country-specific demographic, medical, lifestyle, and geoenvironmental risk factors for cerebral aneurysm rupture in the developing Asian country of Mongolia. First-time estimation of the crude national incidence of aneurysmal subarachnoid hemorrhage (aSAH).MethodsA retrospective analysis of all intracranial digital subtraction angiographies (DSA) acquired in Mongolia during the 2‑year period 2016–2017 (1714 examinations) was performed. During this period, DSA was used as primary diagnostic imaging modality for acute severe neurological symptoms in the sole hospital nationwide dedicated to neurological patients. The catchment area of the hospital included the whole country. Patients with incidental and ruptured aneurysms were reviewed with respect to their medical history and living conditions. The data was used to install a Mongolian aneurysm registry.ResultsThe estimated annual crude incidence of cerebral aneurysm rupture was 6.71 for the country of Mongolia and 14.53 per 100,000 persons for the capital region of Ulaanbaatar. Risk factors common in developed countries also applied for the Mongolian population: A medical history of hypertension, smoking or the presence of multiple aneurysms led to a higher relative risk of rupture. In contrast, female gender was not associated with a higher risk in this national cohort. Males pursuing a traditional nomadic living may exhibit a specifically high risk of rupture.ConclusionDisease management of over 200 individuals/year with aSAH constitutes a socioeconomic burden in Mongolia. Efforts to raise awareness of the risk factors hypertension and smoking among the Mongolian population are desirable. Measures to improve the nationwide availability of modern neurovascular treatment options are currently under consideration.

Incidence and Outcome of Aneurysmal Subarachnoid Hemorrhage: The Swiss Study on Subarachnoid Hemorrhage (Swiss SOS).

The purpose of this study was to assess nationwide incidence and outcomes of aneurysmal subarachnoid hemorrhage (aSAH). The Swiss SOS (Swiss Study on Subarachnoid Hemorrhage) was established in 2008 and offers the unique opportunity to provide this data from the point of care on a nationwide level. All patients with confirmed aneurysmal subarachnoid hemorrhage admitted between January 1, 2009 and December 31, 2014, within Switzerland were recorded in a prospective registry. Incidence rates were calculated based on time-matched population data. Admission parameters and outcomes at discharge and at 1 year were recorded. We recorded data of 1787 consecutive patients. The incidence of aneurysmal subarachnoid hemorrhage in Switzerland was 3.7 per 100 000 persons/y. The number of female patients was 1170 (65.5%). With a follow-up rate of 91.3% at 1 year, 1042 patients (58.8%) led an independent life according to the modified Rankin Scale (0-2). About 1 in 10 patients survived in a dependent state (modified Rankin Scale, 3-5; n=185; 10.4%). Case fatality was 20.1% (n=356) at discharge and 22.1% (n=391) after 1 year. The current incidence of aneurysmal subarachnoid hemorrhage in Switzerland is lower than expected and an indication of a global trend toward decreasing admissions for ruptured intracranial aneurysms. Registration: URL: https://www.clinicaltrials.gov. Unique identifier: NCT03245866.

Abdominal aortic aneurysm is associated with subarachnoid hemorrhage

BackgroundAlthough intracranial aneurysms (IA) and abdominal aortic aneurysms (AAA) share similar risk factors, little is known about the relationship between them. Previous studies have shown an increased incidence of IA...

Smoking habits and detection rate of unruptured intracranial aneurysms and incidence rate of subarachnoid haemorrhage in Norway between 2008 and 2015

ObjectiveThe aim of this study was to investigate the detection rate of unruptured intracranial aneurysms (UIAs) and incidence of aneurysmal subarachnoid haemorrhage (SAH) in relation to the rapidly changing smoking rates in Norway between 2008 and 2015.MethodsThe registry-based study included all patients (≥ 16 years old) admitted to a hospital in Norway between 2008 and 2015 with a primary diagnosis of aneurysmal SAH or an outpatient diagnosis of UIAs. Age group–specific and total detection rate of UIAs and incidence rate of SAH over the years were calculated. Age group–specific data on smoking habits was retrieved from a national annual survey representative of the whole Norwegian population.ResultsThe rate of daily smokers decreased by 48% between 2008 and 2015. The detection rate of UIAs decreased by 47% from 17.3 in 2008 to 9.3 per 100,000 persons in 2015, and the incidence of SAH decreased by 30% from 11.3 in 2008 to 7.9 per 100,000 persons in 2015. The average annual decline in prevalence of daily smoking, UIA detection rate, and SAH incidence was 6.9%, 6.7%, and 4.3% per year, respectively. Multinomial logistic regression analyses revealed that the correlation between the decline in estimated daily smoking rates and decline in detection rate of UIAs (hazard ratio 52.5 CI = (14.9,∞), p < 0.00001) and incidence of SAH (hazard ratio 11.8 CI=(5.6,32.5), p < 0.00001) are statistically significant. The association is particularly strong in young and middle-aged cohorts (< 66 years old).ConclusionIt is likely that reducing cigarette smoking on a population-based level strongly reduces the rates of UIAs and SAH.

Aneurysmal subarachnoid hemorrhage in patients with migraine and tension headache: A cohort comparison study

Migraine headache is a common condition with an estimated lifetime prevalence of greater than 20%. While it is a well-established risk factor for cardiovascular disease and ischemic stroke, its association with subarachnoid hemorrhage is largely unexplored. We sought to compare the incidence of aneurysmal subarachnoid hemorrhage in a cohort of migraine patients with a cohort of patients with tension headache. A cohort comparison study utilizing the MarketScan insurance claims database compared patients diagnosed with migraine who were undergoing treatment with abortive or prophylactic pharmacotherapy (treatment cohort) and patients diagnosed with tension headache who had never been diagnosed with a migraine and who were naïve to migraine pharmacotherapy (control cohort). Patients with major pre-existing risk factors for aSAH were excluded from the study, and minor risk factors such as smoking status and hypertension were accounted for using coarsened exact matching (CEM) and subsequent cox proportional-hazards (CPH) regression. More than 679,000 patients (~125,000 treatment and ~ 550,000 control) with an average follow-up of more than three years were analyzed for aneurysmal subarachnoid hemorrhage. CPH regression on matched data showed that treated migraine patients had a significantly lower hazard of aneurysmal subarachnoid hemorrhage compared with tension headache patients (HR = 0.40, 95% CI: 0.19 – 0.86, p = 0.02). This large cohort comparison study, analyzing more than 679,000 patients, demonstrated that migraine patients undergoing pharmacologic treatment had a lower hazard of aneurysmal subarachnoid hemorrhage than patients diagnosed with tension headaches. Future work specifically focusing on migraine medications may identify the mechanisms underlying this association.

Aneurysmal subarachnoid hemorrhage: long-term trends in incidence and survival in Olmsted County, Minnesota.

Recent population-based and hospital cohort studies have reported a decreasing incidence of aneurysmal subarachnoid hemorrhage (aSAH) and declining aSAH-associated case-fatality rates. Principal drivers of these trends are debated, but improvements in smoking cessation and hypertension control may be critical factors. The population-based medical records linkage system of the Rochester Epidemiological Project was used to document aSAH incidence and 30-day case fatality rates during a 20-year study period (1996-2016) in Olmsted County, Minnesota. Incidence rates in the study period were compared with data from a previous Olmsted County study concerning aSAH incidence from 1965 to 1995 and with regional trends in tobacco use. One hundred nineteen incident cases of aSAH were included. The median age at hemorrhage was 59 years (range 16-94 years), and 74 patients were female (62.2%). The overall average annual aSAH incidence rate was 4.2/100,000 person-years (P-Y). The aSAH incidence rate decreased from 5.7/100,000 in 1996 to 3.5/100,000 P-Y in 2011-2016. The overall aSAH-associated 30-day case-fatality rate was 21.9% and declined by approximately 0.5% annually. An accelerated decline in the fatality rate (0.9%/year) was observed from 2006-2016. Smoking among adult Olmsted County residents decreased from 20.4% in 2000 to 9.1% in 2018. A decline in the incidence of aSAH and 30-day case-fatality rate from 1996 to 2016 was observed, as well as an accelerated decline of the fatality rate from 2006 to 2016. These findings confirm and extend the trends reported by prior studies in the same population. The decrease in aSAH in the years studied paralleled a noticeable reduction in the population smoking rates.