Hemorrhage From Arteriovenous Malformations During Pregnancy

Abstract BACKGROUND: Previous hemorrhage, deep venous drainage, and deep location are established risk factors for arteriovenous malformation (AVM) hemorrhage. Although pregnancy is an assumed risk factor, there is a relative paucity of data to support this neurosurgical tenet. OBJECTIVE: To elucidate the hemorrhage rate of AVMs during pregnancy. METHODS: We reviewed the records of 54 women with an angiographic diagnosis of an AVM at our institution. Annual hemorrhage rates were calculated as the ratio of the number of bleeds to total number of patient-years of follow-up. Patient-years of follow-up were tallied assuming lesion presence from birth until AVM obliteration. The Cox proportional hazards model for hemorrhage with pregnancy as the time-dependent variable was used to calculate the hazard ratio. RESULTS: Five hemorrhages in 4 patients occurred over 62 pregnancies, yielding a hemorrhage rate of 8.1% per pregnancy or 10.8% per year. Over the remaining 2461.3 patient-years of follow-up, only 28 hemorrhages occurred, yielding an annual hemorrhage rate of 1.1%. The hazard ratio for hemorrhage during pregnancy was 7.91 (P = 2.23 × 10−4), increasing to 18.12 (P = 7.31 × 10−5) when limiting the analysis to patient follow-up up to age 40. CONCLUSION: Because of the increased risk of hemorrhage from AVMs during pregnancy, we recommend intervention in women who desire to bear children, particularly if the AVM has bled. If the AVM is discovered during pregnancy, we recommend early intervention if it has ruptured; if it is unruptured, we recommend comprehensive counseling, weighing risks of intervention against continuation of pregnancy without intervention.

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Elevated plasma growth and differentiation factor 15 predicts incident anemia in older adults aged 60 years and older

The Journals of Gerontology Series A ◽

10.1093/gerona/glaa324 ◽

2020 ◽

Author(s):

Yuko Yamaguchi ◽

Marta Zampino ◽

Toshiko Tanaka ◽

Stefania Bandinelli ◽

Yusuke Osawa ◽

...

Keyword(s):

Older Adults ◽

Proportional Hazards ◽

Proportional Hazards Model ◽

Cox Proportional Hazards ◽

Cox Proportional Hazards Model ◽

Differentiation Factor ◽

Hazards Model ◽

Increased Risk ◽

The Relationship

Abstract Background Anemia is common in older adults and associated with greater morbidity and mortality. The causes of anemia in older adults have not been completely characterized. Although elevated circulating growth and differentiation factor 15 (GDF-15) has been associated with anemia in older adults, it is not known whether elevated GDF-15 predicts the development of anemia. Methods We examined the relationship between plasma GDF-15 concentrations at baseline in 708 non-anemic adults, aged 60 years and older, with incident anemia during 15 years of follow-up among participants in the Invecchiare in Chianti (InCHIANTI) Study. Results During follow-up, 179 (25.3%) participants developed anemia. The proportion of participants who developed anemia from the lowest to highest quartile of plasma GDF-15 was 12.9%, 20.1%, 21.2%, and 45.8%, respectively. Adults in the highest quartile of plasma GDF-15 had an increased risk of developing anemia (Hazards Ratio 1.15, 95% Confidence Interval 1.09, 1.21, P<.0001) compared to those in the lower three quartiles in a multivariable Cox proportional hazards model adjusting for age, sex, serum iron, soluble transferrin receptor, ferritin, vitamin B12, congestive heart failure, diabetes mellitus, and cancer. Conclusions Circulating GDF-15 is an independent predictor for the development of anemia in older adults.

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Abstract WP79: Choice Of Treatment And Effect On Hemorrhage Rates Of Unruptured Intracranial Aneurysms

Stroke ◽

10.1161/str.44.suppl_1.awp79 ◽

2013 ◽

Vol 44 (suppl_1) ◽

Author(s):

James Torner ◽

Jie Zhang ◽

David Piepgras ◽

John Huston ◽

Irene Meissner ◽

...

Keyword(s):

Intracranial Aneurysms ◽

Proportional Hazards ◽

Proportional Hazards Model ◽

Interventional Procedure ◽

Careful Consideration ◽

Cox Proportional Hazards ◽

Cox Proportional Hazards Model ◽

Unruptured Intracranial Aneurysms ◽

Increased Risk

INTRODUCTION: The decision regarding whether to perform an interventional procedure as a strategy to prevent hemorrhage of an unruptured intracranial aneurysm (UIA) requires careful consideration of procedural risk and the UIA natural history. No randomized trial data are available. The International Study of Unruptured Intracranial Aneurysms (ISUIA) included a prospective cohort, examining hemorrhage risk and treatment risk. Hypothesis: The purpose of this analysis was to compare the factors related to treatment selection and determination of the number of hemorrhages prevented. Methods: Patients were allocated into the initial treatment and untreated cohorts based upon observation or treatment practices in 61 centers from 1991-1998. 1691 patients were in the observational cohort, 471 were in the endovascular cohort and 1917 patients were in the surgical cohort. The cohorts were followed for a median follow-up of 9.2 years. Outcomes were determined prospectively and with central review. The data were grouped together and analyzed to determine treatment decisions. A Cox proportional hazards model predicting hemorrhage developed in the observation cohort and was applied to the surgery and endovascular cohorts across the follow-up period. Results: Significant baseline variable differences between treated and observed patients were aneurysm size, symptoms, age, prior SAH group, geographical region, treatment percentage, aneurysm daughter sacs or multiple lobes, and history of hypertension, smoking and myocardial infarction. Aneurysm site and family history were not significant. Site, size, and aspirin use were significant predictors of hemorrhage. Long-term the predicted hemorrhage rates were 6.7% at 5 years and 8.0% at 10 years in the surgery group and 8.1% and 9.6% for the endovascular group, respectively. For comparison the rates in the observed cohort were 4.1% and 4.8%, respectively. Conclusions: Decisions for treatment are influenced by patient characteristics such as age and medical history, aneurysm characteristics such as size and morphology and center and regional practices. Patients in the treated cohorts were at moderately increased risk for hemorrhage compared to those in the observed cohort.

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Survival of Captive Chimpanzees: Impact of Location and Transfers

10.1101/068858 ◽

2016 ◽

Author(s):

Michael S. Lauer

Keyword(s):

Proportional Hazards ◽

Proportional Hazards Model ◽

Premature Mortality ◽

Cox Proportional Hazards ◽

Cox Proportional Hazards Model ◽

Hazards Model ◽

Increased Risk ◽

Random Survival Forests ◽

Survival Forests

AbstractTo inform the retirement of NIH-owned chimpanzees, we analyzed the outcomes of 764 NIH-owned chimpanzees that were located at various points in time in at least one of 4 specific locations. All chimpanzees considered were alive and at least 10 years of age on January 1, 2005; transfers to a federal sanctuary began a few months later. During a median follow-up of just over 7 years, there were 314 deaths. In a Cox proportional hazards model that accounted for age, sex, and location (which was treated as a time-dependent covariate), age and sex were strong predictors of mortality, but location was only marginally predictive. Among 273 chimpanzees who were transferred to the federal sanctuary, we found no material increased risk in mortality in the first 30 days after arrival. During a median follow-up at the sanctuary of 3.5 years, age was strongly predictive of mortality, but other variables – sex, season of arrival, and ambient temperature on the day of arrival – were not predictive. We confirmed our regression findings using random survival forests. In summary, in a large cohort of captive chimpanzees, we find no evidence of materially important associations of location of residence or recent transfer with premature mortality.

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Alcohol Use Disorders and Increased Risk of Adverse Birth Complications and Outcomes: An 11-Year Nationwide Cohort Study

International Journal of Environmental Research and Public Health ◽

10.3390/ijerph17228515 ◽

2020 ◽

Vol 17 (22) ◽

pp. 8515

Author(s):

Sarah Soyeon Oh ◽

Yongho Jee ◽

Eun-Cheol Park ◽

Young Ju Kim

Keyword(s):

Alcohol Use ◽

Alcohol Dependence ◽

Proportional Hazards ◽

Proportional Hazards Model ◽

Alcohol Use Disorders ◽

Cox Proportional Hazards ◽

Hazard Ratio ◽

Cox Proportional Hazards Model ◽

Birth Complications ◽

Increased Risk

For women who suffer from Alcohol Use Disorders (AUDs), the use of alcohol before and/or during pregnancy may result in various birth complications, including miscarriage, stillbirth, or preterm delivery. Thus, this study aimed to explore whether Alcohol Use Disorders (AUDs) are associated with increased risk of adverse birth complications and outcomes. A total of 76,799 deliveries between 2003 and 2013 in the Korean National Health Insurance Service National Sample Cohort (NHIS-NSC) were analyzed. Women with an AUD diagnosis preceding delivery were identified as individuals with alcohol dependence. A multivariate Cox proportional hazards model was used to estimate the hazard ratio of adverse birth complications and outcomes associated with alcohol dependence. Diagnosis of an AUD was associated with increased risk of adverse birth complications (Hazard Ratio [HR]: 1.15, 95% CI: 1.01–1.31, p = 0.0302). This was especially the case for women whose AUD diagnosis was in the same year as their delivery (HR: 1.53, 95% CI: 1.24–1.88, p < 0.0001). AUDs were associated with increased risk of adverse birth outcomes, especially when prevalent in the same year as a woman’s delivery. Our study confirms that the monitoring of expecting women with a diagnosis of alcohol-related problems may be useful in preventing adverse birth complications.

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Risk of Blindness Among Patients With Diabetes and Newly Diagnosed Diabetic Retinopathy

10.2337/figshare.13477362.v1 ◽

2021 ◽

Author(s):

Charles C. Wykoff ◽

Rahul N. Khurana ◽

Quan Dong Nguyen ◽

Scott P. Kelly ◽

Flora Lum ◽

...

Keyword(s):

Diabetic Retinopathy ◽

Proportional Hazards ◽

Proportional Hazards Model ◽

Significant Risk ◽

Cox Proportional Hazards ◽

Cox Proportional Hazards Model ◽

Newly Diagnosed ◽

Increased Risk ◽

Good Vision

OBJECTIVE To evaluate association between initial diabetic retinopathy (DR) severity/risk of blindness in patients with newly diagnosed DR/good vision in the U.S. RESEARCH DESIGN AND METHODS Retrospective cohort study of adult patients with good vision (20/40 or better)/newly diagnosed DR between 1 January 2013 and 31 December 2017 (index date) in the American Academy of Ophthalmology’s IRIS® Registry. Primary exposure of interest, DR severity at index: mild nonproliferative DR (NPDR), moderate NPDR, severe NPDR, proliferative DR (PDR). Main outcome measure: development of sustained blindness (SB), defined as study eyes with Snellen visual acuity readings of 20/200 or worse at two separate visits ≥3 months apart that did not improve beyond 20/100. RESULTS Among 53,535 eligible eyes (mean follow-up, 662.5 days), 678 (1.3%) eyes developed SB. Eyes with PDR at index represented 10.5% (5,629/53,535) of the analysis population but made up 26.5% (180/678) of eyes that developed SB. Kaplan-Meier analysis revealed that eyes with moderate NPDR, severe NPDR, and PDR at index were 2.6, 3.6, and 4.0 times more likely, respectively, to develop SB after 2 years of DR diagnosis versus eyes with mild DR at index. In a Cox proportional hazards model adjusted for index characteristics/development of ocular conditions during follow-up, eyes with PDR had an increased risk of developing SB versus eyes with mild NPDR at index (hazard ratio, 2.26; 95% CI, 2.09−2.45). CONCLUSIONS In this longitudinal ophthalmologic registry population involving eyes with good vision, more advanced DR at first diagnosis was a significant risk factor for developing SB.

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Effect of multiple episodes of acute kidney injury on mortality: an observational study

Clinical Kidney Journal ◽

10.1093/ckj/sfz199 ◽

2020 ◽

Author(s):

Heather Walker ◽

Nicosha De Souza ◽

Simona Hapca ◽

Miles D Witham ◽

Samira Bell

Keyword(s):

Acute Kidney Injury ◽

Proportional Hazards ◽

Proportional Hazards Model ◽

Kidney Injury ◽

Patient Characteristics ◽

Cox Proportional Hazards ◽

Hazard Ratio ◽

Cox Proportional Hazards Model ◽

Hazards Model ◽

Increased Risk

Abstract Background Patients who survive an episode of acute kidney injury (AKI) are more likely to have further episodes of AKI. AKI is associated with increased mortality, with a further increase with recurrent episodes. It is not clear whether this is due to AKI or as a result of other patient characteristics. The aim of this study was to establish whether recurrence of AKI is an independent risk factor for mortality or if excess mortality is explained by other factors. Methods This observational cohort study included adult people from the Tayside region of Scotland, with an episode of AKI between 1 January 2009 and 31 December 2009. AKI was defined using the creatinine-based Kidney Disease: Improving Global Outcomes definition. Associations between recurrent AKI and mortality were examined using a Cox proportional hazards model. Results Survival was worse in the group identified to have recurrent AKI compared with those with a single episode of AKI [hazard ratio = 1.49, 95% confidence interval (CI) 1.37–1.63; P < 0.001]. After adjustment for comorbidities, stage of reference AKI, sex, age, medicines that predispose to renal impairment or, in the 3 months prior to the reference AKI, deprivation and baseline estimated glomerular filtration rate (eGFR), recurrent AKI was independently associated with an increase in mortality (hazard ratio = 1.25, 95% CI 1.14–1.37; P < 0.001). Increasing stage of reference AKI, age, deprivation, baseline eGFR, male sex, previous myocardial infarction, cerebrovascular disease and diuretic use were all associated with an increased risk of mortality in patients with recurrent AKI. Conclusions Recurrent AKI is associated with increased mortality. After adjusting for patient characteristics, the increase in mortality is independently associated with recurrent AKI and is not solely explained by other risk factors.

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P4155Multiple modality biomarkers predict ischemic heart disease in middle-aged men from the general population during a 21-year follow-up

European Heart Journal ◽

10.1093/eurheartj/ehz745.0727 ◽

2019 ◽

Vol 40 (Supplement_1) ◽

Author(s):

M Sakalaki ◽

P.-O Hansson ◽

A Rosengren ◽

E Thunstrom ◽

A Pivodic ◽

...

Keyword(s):

General Population ◽

Proportional Hazards ◽

Proportional Hazards Model ◽

High Sensitivity ◽

Cox Proportional Hazards ◽

Hazard Ratio ◽

Cox Proportional Hazards Model ◽

Blood Samples ◽

Hazards Model

Abstract Background Ischemic heart disease (IHD) often develops after decades of preceding subclinical coronary atherosclerosis. An early prediction of risk for IHD in a general population would be helpful for preventive decision-making. It is well known that biomarkers including troponine, natriuretic peptides and inflammatory biomarkers are useful prognostic predictors for IHD, their long-term predictive values in a general population for incident IHD have not been studied. Purpose The aim of the study was to investigate the predictive value of multi-modality biomarkers on the incident IHD in a random male sample from the general population followed from the age of 50 to 71 years. Method “The study of Men Born in 1943” is a longitudinal cohort study of men living in the city of Gothenburg in Sweden. All patients underwent a baseline examination in 1993, which included physical examination, questionnaires and blood samples. Because of multifactorial nature of atherosclerosis, a panel of biomarkers representing multiple mechanisms such as high-sensitivity troponine (hs-TNT), interleukin-6 (IL-6), cystatin C, high-sensitivity C-reactive protein (hs-CRP), urat, ferritin, and N-terminal prohormone of brain natriuretic peptide (NT-proBNP) were analyzed from blood samples collected at 50 years of age. Incident IHD was defined as new-onset one of following (myocardial infarction, hospitalized unstable angina and intervention with either percutaneous coronary intervention (PCI) or coronary artery bypass graft (CABG) during 1993–2014. The impact of biomarkers on incident IHD was studied using univariable, followed by stepwise and multivariable Cox proportional hazards models. Results Among the, 753 patients in the study, 105 patients (13,9%) developed IHD during 21 years of follow up with an event rate per 1000 person years 7.49 and a 95% confidence interval (CI) of 6.19 - 9.07. In Cox proportional hazards model for time to first occurrence of IHD, univariable analyses showed that multi-modality biomarker (CRP >1 mg/ml, NT-proBNP >100 pg/mL, troponin >10 ng/L, IL-6 >8 ng/L) provide most powerful prediction, followed by total cholesterol and fasting plasma glucose. In multivariable Cox proportional hazards model for time to first of IHD, above four-biomarker combination modality remains a most powerful predictor with risk increased by one additional biomarker [Hazard Ratio (95% CI): 1.69 (1.26 - 2.26), p=0.0004], followed by total cholesterol (mmol/L) with risk increased by one [Hazard Ratio (95% CI: 1.31 (1.09 - 1.56), p=0.0031], and fasting plasma glucose (mmol/L) with risk increased by one unit [Hazard Ratio (95% CI): 1.11 (1.01 - 1.22), p=0.038]. Conclusion A multi-modality biomarker strategy can be used to predict increased risk of developing IHD during the following two decades after 50 years, enabling us to identify individuals who might benefit from early intensive risk modification to prevent the development of IHD.

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Risk of Blindness Among Patients With Diabetes and Newly Diagnosed Diabetic Retinopathy

10.2337/figshare.13477362 ◽

2021 ◽

Author(s):

Charles C. Wykoff ◽

Rahul N. Khurana ◽

Quan Dong Nguyen ◽

Scott P. Kelly ◽

Flora Lum ◽

...

Keyword(s):

Diabetic Retinopathy ◽

Proportional Hazards ◽

Proportional Hazards Model ◽

Significant Risk ◽

Cox Proportional Hazards ◽

Cox Proportional Hazards Model ◽

Newly Diagnosed ◽

Increased Risk ◽

Good Vision

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Apolipoprotein Eɛ2 Is Associated with New Hemorrhage Risk in Brain Arteriovenous Malformations

Neurosurgery ◽

10.1227/01.neu.0000209605.18358.e5 ◽

2006 ◽

Vol 58 (5) ◽

pp. 838-843 ◽

Cited By ~ 33

Author(s):

Ludmila Pawlikowska ◽

K.Y. Trudy Poon ◽

Achal S. Achrol ◽

Charles E. McCulloch ◽

Connie Ha ◽

...

Keyword(s):

Confidence Interval ◽

Proportional Hazards ◽

Clinical Presentation ◽

Proportional Hazards Model ◽

Cox Proportional Hazards ◽

Cox Proportional Hazards Model ◽

Hazards Model ◽

Increased Risk ◽

Brain Avm

Abstract OBJECTIVE: Patients with brain arteriovenous malformation (AVM) are at life-threatening risk of intracranial hemorrhage (ICH). Identification of genetic variants associated with increased new ICH risk would facilitate risk stratification and guide therapeutic intervention. METHODS: Brain AVM patients evaluated at University of California, San Francisco or Kaiser Permanente Northern California were followed longitudinally. Primary outcome was new ICH after diagnosis; censoring events were any AVM treatment or last follow-up examination. The association of ApoE ɛ2 and ɛ4 genotype with new ICH was evaluated by Kaplan-Meier survival analysis and further characterized via a Cox proportional hazards model. RESULTS: We genotyped 284 brain AVM patients (50% women; 57% Caucasian; median follow-up time, 0.3 yr) including 18 patients with a history of new ICH). ApoE ɛ2, but not ApoE ɛ4 genotype, was associated with new ICH (P = 0.0052). ApoE ɛ2 carriers had fivefold increased risk of new ICH (hazard ratio, 5.09; 95% confidence interval, 1.46–17.7; P = 0.010; Cox proportional hazards model adjusting for race/ethnicity and clinical presentation). Subset analysis in the largest homogenous ethnic subcohort (Caucasians) confirmed the increased risk of new ICH in ApoE ɛ2 carriers (hazard ratio, 8.71; 95% confidence interval, 1.4–53.9; P = 0.020; multivariate model adjusting for clinical presentation). CONCLUSION: ApoE genotype may influence the risk of ICH in the natural course of brain AVM. The identification of genetic predictors of ICH risk may facilitate estimation of AVM natural history risk and individualize clinical decision-making and therapeutic recommendations.

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Risk factors associated with major adverse cardiac and cerebrovascular events following percutaneous coronary intervention: a 10-year follow-up comparing random survival forest and Cox proportional-hazards model

BMC Cardiovascular Disorders ◽

10.1186/s12872-020-01834-1 ◽

2021 ◽

Vol 21 (1) ◽

Author(s):

Maryam Farhadian ◽

Sahar Dehdar Karsidani ◽

Azadeh Mozayanimonfared ◽

Hossein Mahjub

Keyword(s):

Proportional Hazards ◽

Proportional Hazards Model ◽

Coronary Intervention ◽

Cox Proportional Hazards ◽

Cox Proportional Hazards Model ◽

Hazards Model ◽

Cerebrovascular Events ◽

Long Term Follow Up ◽

Stent Length

Abstract Background Due to the limited number of studies with long term follow-up of patients undergoing Percutaneous Coronary Intervention (PCI), we investigated the occurrence of Major Adverse Cardiac and Cerebrovascular Events (MACCE) during 10 years of follow-up after coronary angioplasty using Random Survival Forest (RSF) and Cox proportional hazards models. Methods The current retrospective cohort study was performed on 220 patients (69 women and 151 men) undergoing coronary angioplasty from March 2009 to March 2012 in Farchshian Medical Center in Hamadan city, Iran. Survival time (month) as the response variable was considered from the date of angioplasty to the main endpoint or the end of the follow-up period (September 2019). To identify the factors influencing the occurrence of MACCE, the performance of Cox and RSF models were investigated in terms of C index, Integrated Brier Score (IBS) and prediction error criteria. Results Ninety-six patients (43.7%) experienced MACCE by the end of the follow-up period, and the median survival time was estimated to be 98 months. Survival decreased from 99% during the first year to 39% at 10 years' follow-up. By applying the Cox model, the predictors were identified as follows: age (HR = 1.03, 95% CI 1.01–1.05), diabetes (HR = 2.17, 95% CI 1.29–3.66), smoking (HR = 2.41, 95% CI 1.46–3.98), and stent length (HR = 1.74, 95% CI 1.11–2.75). The predictive performance was slightly better by the RSF model (IBS of 0.124 vs. 0.135, C index of 0.648 vs. 0.626 and out-of-bag error rate of 0.352 vs. 0.374 for RSF). In addition to age, diabetes, smoking, and stent length, RSF also included coronary artery disease (acute or chronic) and hyperlipidemia as the most important variables. Conclusion Machine-learning prediction models such as RSF showed better performance than the Cox proportional hazards model for the prediction of MACCE during long-term follow-up after PCI.

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