Daily Low-dose Aspirin Research Articles

Serum Transaminases and Older Adults: Distribution and Associations With All-Cause Mortality.

Alanine aminotransferase (ALT) and aspartate aminotransferase (AST) are commonly ordered tests in general medical practice. However, their distribution and significance in older adults are understudied. As such, we aimed to evaluate sex-stratified distribution of both ALT and AST in older adults (≥70 years) and assess for associations with mortality. Post-hoc analysis of the ASPirin in Reducing Events in the Elderly (ASPREE) randomized, placebo-controlled trial of daily low-dose aspirin for initially relatively healthy older persons. Univariate analysis and multiple logistic regression were used to explore baseline characteristics. Cox regression and restricted cubic splines were used to examine links between transaminase levels and mortality. Of the 11 853 participants with ALT and AST levels, 1 054 (8.9%) deaths were recorded over a median of 6.4 (interquartile range [IQR] 5.4-7.6) years. For ALT, the lowest quintiles for males and females were 6-15 and 5-13 U/L, respectively; for AST, the lowest quintiles were 8-18 and 7-17 U/L, respectively. On both univariate and models adjusted for covariates including age, body mass index, frailty, diabetes, and kidney disease, males and females in the lowest quintile of ALT had an increased hazard of mortality (aHR 1.51 [95% confidence interval {CI} 1.14-1.99] and aHR 1.39 [95% CI 1.03-1.88], respectively). For the lowest quintile of AST, only males were at increased risk (aHR 1.33 [95% CI 1.04-1.70]). Associations remained significant when removing outliers. Low ALT levels independently confer an increased hazard of mortality for older males and females; low AST only affected older male survival. Further evaluation of mechanisms would be worthwhile, and re-evaluating the lower limit of normal for ALT in older adults should be considered.

Low-Dose Aspirin and Progression of Age-Related Hearing Loss

Age-related hearing loss is common in an aging population, affecting communication and contributing to a worsened quality of life. It occurs as a result of cochlear degeneration and may be further exacerbated by inflammation and microvascular changes, as observed in animal models. To compare the effect of daily low-dose aspirin vs placebo on the progression of age-related hearing loss in healthy older adults. A prespecified secondary analysis was conducted of the Aspirin in Reducing Events in the Elderly (ASPREE) randomized clinical trial. Participants were 279 healthy community-dwelling individuals living in Australia who were aged 70 years or older and free of overt cardiovascular diseases, dementia, and life-limiting illnesses. Participants were recruited between January 1, 2010, and December 31, 2014, and followed up over 3 years. Statistical analysis was completed from June to December 2023. A 100-mg daily dose of enteric-coated aspirin or matching placebo. Hearing measures were air conduction audiometry and binaural speech perception in noise. Assessments were conducted at baseline, 18 months, and 3 years. The change from baseline hearing measures were analyzed using an intention to treat approach. Aspirin and placebo were compared using mixed linear regression models adjusting for age, sex, diabetes, and smoking. Of 279 participants, 154 (55%) were male, and the median age at baseline was 73.1 years (IQR, 71.5-76.2 years). A total of 98 of 138 participants (71%) in the aspirin group and 94 of 141 participants (67%) in the placebo group reported experiencing hearing loss at baseline. Compared with placebo, aspirin did not affect the changes in mean (SD) 4-frequency average hearing threshold from baseline to year 3 (aspirin: baseline, 27.8 [13.3] dB; year 3, 30.7 [13.7] dB; difference, 3.3 [3.9] dB; placebo: baseline, 27.5 [12.6] dB; year 3, 30.9 [13.8] dB; difference, 3.0 [4.8] dB; P = .55) nor any other tested frequencies. An increase in air conduction threshold indicates a deterioration in hearing. Similarly, for the mean (SD) speech reception threshold, there was no significant difference observed between the aspirin and placebo group at the year 3 follow-up assessment (aspirin: baseline, -9.9 [3.8] dB; year 3, -9.1 [3.8] dB; difference, 0.9 [2.9] dB; placebo: baseline, -10.5 [7.1] dB; year 3, -9.6 [4.1] dB; difference, 0.9 [5.9] dB; P = .86). The findings were consistent across sex, age groups, diabetic and smoking status. In this secondary analysis of the ASPREE randomized clinical trial, low-dose aspirin did not affect the progression of age-related hearing loss. More investigation is warranted on whether a longer follow-up or the use of a more powerful anti-inflammatory agent might prove beneficial. anzctr.org.au Identifier: ACTRN12614000496617.

Evaluation of Aspirin Prescribing and Gastrointestinal Bleeding in Adults 60 Years of Age and Older in a Large, Academic Health System.

Background National guidelines no longer recommend adults 60 years of age and older to begin treatment with low-dose daily aspirin for primary prevention of atherosclerotic cardiovascular disease (CVD) due to a lack of proven net benefit and a higher risk of bleeding. Objective The objective of this cross-sectional retrospective analysis was to evaluate the appropriateness of low-dose aspirin prescribing and subsequent gastrointestinal bleeding in older persons receiving primary care in a large academic health system. Setting Large, academic health system within Colorado. Patients Patients with an active order for daily low-dose aspirin as of July 1, 2021, were assessed for appropriateness based on indication (primary vs secondary prevention) and use of a concomitant proton-pump inhibitor (PPI). Incident gastrointestinal bleeds (GIBs) in the subsequent 12 months and GIB risk factors were also evaluated. Results A total of 19,525 patients were included in the analysis. Eighty-nine percent of patients identified as White and 54% identified as male. Of the total cohort, 44% had CVD and 19% were co-prescribed a PPI. GIB occurred in 247 patients (1.27%) within the subsequent year. Risk factors significantly associated with a GIB within 1 year included: history of GIB, history of peptic ulcer disease, other esophageal issue (esophagitis, Barrett's esophagus, Mallory Weiss tears, etc.), 75 years of age or older, and history of gastroesophageal reflux disease. Conclusion This evaluation found that many older persons at this institution may be inappropriately prescribed aspirin, providing opportunities for pharmacists to improve medication safety by deprescribing aspirin among primary prevention patients or potentially co-prescribing a PPI in secondary prevention patients.

318 Discovering Subgroups with Supervised Machine Learning Models for Heterogeneity of Treatment Effect Analysis

OBJECTIVES/GOALS: The goal of the study is to provide insights into the use of machine learning methods as a means to predict heterogeneity of treatment effect (HTE) in participants of randomized clinical trials. METHODS/STUDY POPULATION: Using data from 2,441 participants enrolled in the ASPirin in Reducing Events in the Elderly (ASPREE) randomized controlled trial of daily low-dose aspirin vs placebo in the United States, we developed multivariable risk prediction models for the composite outcome of dementia, disability, or death. We used two machine learning techniques, decision trees and random forests, to develop novel non-parametric outcomes classifiers and generate risk-based subgroups. The comparator method was an extant semi-parametric proportional hazards predictive risk model. We then assessed HTE by examining the 5-year absolute risk reduction (ARR) of aspirin vs placebo in each risk subgroup. RESULTS/ANTICIPATED RESULTS: In the random forest classifier, the ARR at 5 years in the highest risk quintile was 13.7% (95% CI 3.1% to 24.4%). For the semi-parametric proportional hazards model, the ARR in the highest risk quintile was 15.1% (95% CI 4.0% to 26.3%). These results were comparable and provide evidence of the viability of internally developed parsimonious non-parametric machine learning models for HTE analysis. The decision tree model results (5-year ARR = 17.0%, 95% CI= -5.4% to 39.4% in the highest risk subgroup) exhibited more uncertainty in the results. DISCUSSION/SIGNIFICANCE: None of the models detected significant HTE on the relative scale; there was substantial HTE on the absolute scale in three of the models. Treatment benefit on the absolute scale may be regarded as bearing greater clinical importance and may be present even in the absence of benefit on the relative scale.

Aspirin for Metabolic Dysfunction–Associated Steatotic Liver Disease Without Cirrhosis

ImportanceAspirin may reduce severity of metabolic dysfunction–associated steatotic liver disease (MASLD) and lower the incidence of end-stage liver disease and hepatocellular carcinoma, in patients with MASLD. However, the effect of aspirin on MASLD is unknown.ObjectiveTo test whether low-dose aspirin reduces liver fat content, compared with placebo, in adults with MASLD.Design, Setting, and ParticipantsThis 6-month, phase 2, randomized, double-blind, placebo-controlled clinical trial was conducted at a single hospital in Boston, Massachusetts. Participants were aged 18 to 70 years with established MASLD without cirrhosis. Enrollment occurred between August 20, 2019, and July 19, 2022, with final follow-up on February 23, 2023.InterventionsParticipants were randomized (1:1) to receive either once-daily aspirin, 81 mg (n = 40) or identical placebo pills (n = 40) for 6 months.Main Outcomes and MeasuresThe primary end point was mean absolute change in hepatic fat content, measured by proton magnetic resonance spectroscopy (MRS) at 6-month follow-up. The 4 key secondary outcomes included mean percentage change in hepatic fat content by MRS, the proportion achieving at least 30% reduction in hepatic fat, and the mean absolute and relative reductions in hepatic fat content, measured by magnetic resonance imaging proton density fat fraction (MRI-PDFF). Analyses adjusted for the baseline value of the corresponding outcome. Minimal clinically important differences for study outcomes were not prespecified.ResultsAmong 80 randomized participants (mean age, 48 years; 44 [55%] women; mean hepatic fat content, 35% [indicating moderate steatosis]), 71 (89%) completed 6-month follow-up. The mean absolute change in hepatic fat content by MRS was −6.6% with aspirin vs 3.6% with placebo (difference, −10.2% [95% CI, −27.7% to −2.6%]; P = .009). Compared with placebo, aspirin treatment significantly reduced relative hepatic fat content (−8.8 vs 30.0 percentage points; mean difference, −38.8 percentage points [95% CI, −66.7 to −10.8]; P = .007), increased the proportion of patients with 30% or greater relative reduction in hepatic fat (42.5% vs 12.5%; mean difference, 30.0% [95% CI, 11.6% to 48.4%]; P = .006), reduced absolute hepatic fat content by MRI-PDFF (−2.7% vs 0.9%; mean difference, −3.7% [95% CI, −6.1% to −1.2%]; P = .004]), and reduced relative hepatic fat content by MRI-PDFF (−11.7 vs 15.7 percentage points; mean difference, −27.3 percentage points [95% CI, −45.2 to −9.4]; P = .003). Thirteen participants (32.5%) in each group experienced an adverse event, most commonly upper respiratory tract infections (10.0% in each group) or arthralgias (5.0% for aspirin vs 7.5% for placebo). One participant randomized to aspirin (2.5%) experienced drug-related heartburn.Conclusions and RelevanceIn this preliminary randomized clinical trial of patients with MASLD, 6 months of daily low-dose aspirin significantly reduced hepatic fat quantity compared with placebo. Further study in a larger sample size is necessary to confirm these findings.Trial RegistrationClinicalTrials.gov Identifier: NCT04031729

Thromboxane biosynthesis and future events in diabetes: the ASCEND trial.

Thromboxane (TX) A2, released by activated platelets, plays an important role in atherothrombosis. Urinary 11-dehydro-TXB2 (U-TXM), a stable metabolite reflecting the whole-body TXA2 biosynthesis, is reduced by ∼70% by daily low-dose aspirin. The U-TXM represents a non-invasive biomarker of in vivo platelet activation and is enhanced in patients with diabetes. This study assessed whether U-TXM is associated with the risk of future serious vascular events or revascularizations (SVE-R), major bleeding, or cancer in patients with diabetes. The U-TXM was measured pre-randomization to aspirin or placebo in 5948 people with type 1 or 2 diabetes and no cardiovascular disease, in the ASCEND trial. Associations between log U-TXM and SVE-R (n = 618), major bleed (n = 206), and cancer (n = 700) during 6.6 years of follow-up were investigated by Cox regression; comparisons of these associations with the effects of randomization to aspirin were made. Higher U-TXM was associated with older age, female sex, current smoking, type 2 diabetes, higher body size, urinary albumin/creatinine ratio of ≥3 mg/mmol, and higher estimated glomerular filtration rate. After adjustment for these, U-TXM was marginally statistically significantly associated with SVE-R and major bleed but not cancer [hazard ratios per 1 SD higher log U-TXM (95% confidence interval): 1.09 (1.00-1.18), 1.16 (1.01-1.34), and 1.06 (0.98-1.14)]. The hazard ratio was similar to that implied by the clinical effects of randomization to aspirin for SVE-R but not for major bleed. The U-TXM was log-linearly independently associated with SVE-R in diabetes. This is consistent with the involvement of platelet TXA2 in diabetic atherothrombosis.

Digital gangrene: can be the first manifestation of essential thrombocythemia? a case report

Introduction and importance: Essential thrombocythemia (ET) is a rare chronic myeloproliferative hematologic disorder, leading to an elevated platelet count. Two-thirds of patients are asymptomatic during their lifetime, while others may experience symptoms like redness, congestion, and erythromelalgia after long symptom-free intervals. Case presentation: The authors present a rare instance of a 55-year-old female who, despite receiving aspirin and losartan treatment, eventually developed digital gangrene. In further work-ups, she had an elevated platelet count and a positive JAK 2 mutation. Her platelet count was reduced throughout treatment with aspirin, hydroxyurea, and heparin, which was followed by the necrotic tip of her index finger being surgically debrided. Clinical discussion: Significant symptoms, such as severe acrocyanosis and even peripheral gangrene, can be treated with a single dose of aspirin. Daily aspirin consumption withstanding, this case developed the severe form of ET. In addition, while thrombocytosis predisposes patients to thrombotic complications in theory, there is little evidence to support a correlation between absolute platelet count and thrombosis. Conclusion: The initial symptom of ET could be such severe and uncommon that may develop arterial acral thrombosis despite previous daily low-dose aspirin consumption.

Daily low-dose aspirin and incident type 2 diabetes in community-dwelling healthy older adults: a post-hoc analysis of efficacy and safety in the ASPREE randomised placebo-controlled trial

Inflammation has been implicated in the pathogenesis of diabetes. This study investigated the randomised treatment effect of low-dose aspirin on incident type 2 diabetes and fasting plasma glucose (FPG) concentrations among older adults. ASPREE was a double-blind, placebo-controlled trial of daily oral low-dose aspirin. The study population included community-dwelling individuals aged 70 years or older (≥65 years for US minority ethnic groups) in the USA and Australia who were free of cardiovascular disease, independence-limiting physical disability, or dementia. For the post-hoc analysis, we excluded participants with diabetes at baseline or with incomplete or missing incident diabetes data during follow-up. Participants were randomly assigned 1:1 to oral 100 mg daily enteric-coated aspirin or placebo. Incident diabetes was defined as self-reported diabetes, commencement of glucose-lowering medication, or a FPG concentration of 7·0 mmol/L or more assessed at annual follow-up visits among participants with no diabetes at baseline. We used Cox proportional hazards models and mixed-model repeated measures to assess the effect of aspirin on incident diabetes and FPG concentrations in the intention-to-treat population. We assessed major bleeding in participants who had taken at least one dose of study medication. Between March 10, 2010, and Dec 24, 2014, a total of 16 209 participants were included (8086 [49·9%] randomly assigned to aspirin and 8123 [50·1%] randomly assigned to placebo). During a median follow-up of 4·7 years (IQR 3·6-5·7), 995 (in 6·1% individuals) incident cases of type 2 diabetes were recorded (459 in the aspirin group and 536 in the placebo group). Compared with placebo, the aspirin group had a 15% reduction in risk of incident diabetes (hazard ratio 0·85 [95% CI 0·75 to 0·97]; p=0·013) and a slower rate of increase in FPG concentration at year 5 (between-group difference estimate -0·048 mmol/L [95% CI -0·079 to -0·018]; p=0·0017). Major bleeding (major gastrointestinal bleeding, intracranial bleeding, and clinically significant bleeding at other sites) occurred in 510 (3·2%) of 16 104 participants (300 [3·7%] in the aspirin group and 210 [2·6%] in the placebo group). Compared with placebo, the aspirin group had a 44% increase in risk of major bleeding (hazard ratio 1·44 [95% CI 1·21 to 1·72]; p<0·0001). Aspirin treatment reduced the incidence of type 2 diabetes and slowed the increase in FPG concentration but increased major bleeding among community-dwelling older adults. Given the increasing prevalence of type 2 diabetes among older adults, the potential for anti-inflammatory agents such as aspirin to prevent type 2 diabetes or improve glucose levels warrants further study with a comprehensive assessment of all potential safety events of interest. US National Institute on Aging, US National Cancer Institute, National Health and Medical Research Council of Australia, Monash University, and the Victorian Cancer Agency.

Association of plasma high-density lipoprotein cholesterol level with risk of incident dementia: a cohort study of healthy older adults

Recent studies have reported associations between high plasma high-density lipoprotein cholesterol (HDL-C) levels and risk of all-cause mortality, age-related macular degeneration, sepsis and fractures, but associations with dementia risk remain unclear. To determine whether high plasma HDL-C levels are associated with increased incident dementia risk in initially-healthy older people. We conducted a post-hoc analysis of the Aspirin in Reducing Events in the Elderly (ASPREE) trial; a double-blind, randomized, placebo-controlled trial of daily low-dose aspirin in healthy older people. ASPREE recruited 16,703 participants aged ≥70 years (from Australia) and 2411 participants aged ≥65 years (from the US) between 2010 and 2014. Participants had no diagnosed cardiovascular disease, dementia, physical disability, or life-threatening illness at enrolment and were cognitively healthy (3MS score ≥78). All-cause dementia was a primary trial endpoint, and determined by DSM-IV criteria. Cox regression was used to examine hazard ratios between HDL-C categories <40mg/dL, 40-60mg/dL (reference category), 60-80mg/dL, and >80mg/dL and dementia. Restricted cubic spline curves were used to determine nonlinear associations. Data analysis was performed from October 2022 to January 2023. Of the 18,668 participants, 850 (4.6%) cases of incident dementia were recorded over 6.3 (SD 1.8) years. Participants with high HDL-C (>80mg/dL) had a 27% higher risk of dementia (HR 1.27, 95% CI 1.03, 1.58). Age stratified analyses demonstrated that the risk of incident dementia was higher in participants ≥75 years compared to participants <75 years (HR 1.42, 95% CI 1.10, 1.83 vs HR 1.02, 95% CI 0.68, 1.51). Associations remained significant after adjusting for covariates including age, sex, country of enrolment, daily exercise, education, alcohol consumption, weight change over time, non-HDL-C, HDL-C-PRS, and APOE genotype. In a population of initially-healthy older adults aged ≥75 years, high HDL-C levels were associated with increased risk of all-cause dementia. National Institutes of Health, USA; National Health and Medical Research Council Australia; Monash University (Melbourne, VIC, Australia); and the Victorian Cancer Agency (Australia).

Low-Dose Aspirin and the Risk of Stroke and Intracerebral Bleeding in Healthy Older People

Low-dose aspirin has been widely used for primary and secondary prevention of stroke. The balance between potential reduction of ischemic stroke events and increased intracranial bleeding has not been established in older individuals. To establish the risks of ischemic stroke and intracranial bleeding among healthy older people receiving daily low-dose aspirin. This secondary analysis of the Aspirin in Reducing Events in the Elderly (ASPREE) randomized, double-blind, placebo-controlled trial of daily low-dose aspirin was conducted among community-dwelling people living in Australia or the US. Participants were older adults free of symptomatic cardiovascular disease. Recruitment took place between 2010 and 2014, and participants were followed up for a median (IQR) of 4.7 (3.6-5.7) years. This analysis was completed from August 2021 to March 2023. Daily 100-mg enteric-coated aspirin or matching placebo. Stroke and stroke etiology were predetermined secondary outcomes and are presented with a focus on prevention of initial stroke or intracranial bleeding event. Outcomes were assessed by review of medical records. Among 19 114 older adults (10 782 females [56.4%]; median [IQR] age, 74 [71.6-77.7] years), 9525 individuals received aspirin and 9589 individuals received placebo. Aspirin did not produce a statistically significant reduction in the incidence of ischemic stroke (hazard ratio [HR], 0.89; 95% CI, 0.71-1.11). However, a statistically significant increase in intracranial bleeding was observed among individuals assigned to aspirin (108 individuals [1.1%]) compared with those receiving placebo (79 individuals [0.8%]; HR, 1.38; 95% CI, 1.03-1.84). This occurred by an increase in a combination of subdural, extradural, and subarachnoid bleeding with aspirin compared with placebo (59 individuals [0.6%] vs 41 individuals [0.4%]; HR, 1.45; 95% CI, 0.98-2.16). Hemorrhagic stroke was recorded in 49 individuals (0.5%) assigned to aspirin compared with 37 individuals (0.4%) in the placebo group (HR, 1.33; 95% CI, 0.87-2.04). This study found a significant increase in intracranial bleeding with daily low-dose aspirin but no significant reduction of ischemic stroke. These findings may have particular relevance to older individuals prone to developing intracranial bleeding after head trauma. ISRCTN.org Identifier: ISRCTN83772183.

Association of polygenic scores with chronic kidney disease phenotypes in a longitudinal study of older adults

Risk of chronic kidney disease (CKD) is influenced by environmental and genetic factors and increases sharply in individuals 70 years and older. Polygenic scores (PGS) for kidney disease-related traits have shown promise but require validation in well-characterized cohorts. Here, we assessed the performance of recently developed PGSs for CKD-related traits in a longitudinal cohort of healthy older individuals enrolled in the Australian ASPREE randomized controlled trial of daily low-dose aspirin with CKD risk at baseline and longitudinally. Among 11,813 genotyped participants aged 70 years or more with baseline eGFR measures, we tested associations between PGSs and measured eGFR at baseline, clinical phenotype of CKD, and longitudinal rate of eGFR decline spanning up to six years of follow-up per participant. A PGS for eGFR was associated with baseline eGFR, with a significant decrease of 3.9 mL/min/1.73m2 (95% confidence interval -4.17 to -3.68) per standard deviation (SD) increase of the PGS. This PGS, as well as a PGS for CKD stage 3 were both associated with higher risk of baseline CKD stage 3 in cross-sectional analysis (Odds Ratio 1.75 per SD, 95% confidence interval 1.66-1.85, and Odds Ratio 1.51 per SD, 95% confidence interval 1.43-1.59, respectively). Longitudinally, two separate PGSs for eGFR slope were associated with significant kidney function decline during follow-up. Thus, our study demonstrates that kidney function has a considerable genetic component in older adults, and that new PGSs for kidney disease-related phenotypes may have potential utility for CKD risk prediction in advanced age.

Pre-eclampsia.

Pre-eclampsia is a life-threatening disease of pregnancy unique to humans and a leading cause of maternal and neonatal morbidity and mortality. Women who survive pre-eclampsia have reduced life expectancy, with increased risks of stroke, cardiovascular disease and diabetes, while babies from a pre-eclamptic pregnancy have increased risks of preterm birth, perinatal death and neurodevelopmental disabilityand cardiovascular and metabolic disease later in life. Pre-eclampsia is a complex multisystem disease, diagnosed by sudden-onset hypertension (>20 weeks of gestation) and at least one other associated complication, including proteinuria, maternal organ dysfunction or uteroplacental dysfunction. Pre-eclampsia is found only when a placenta is or was recently present and is classified as preterm (delivery <37 weeks of gestation), term (delivery ≥37 weeks of gestation) and postpartum pre-eclampsia. The maternal syndrome of pre-eclampsia is driven by a dysfunctional placenta, which releases factors into maternal blood causing systemic inflammation and widespread maternal endothelial dysfunction. Available treatments target maternal hypertension and seizures, but the only 'cure' for pre-eclampsia is delivery of the dysfunctional placenta and baby, often prematurely. Despite decades of research, the aetiology of pre-eclampsia, particularly of term and postpartum pre-eclampsia, remains poorly defined. Significant advances have been made in the prediction and prevention of preterm pre-eclampsia, which is predicted in early pregnancy through combined screening and is prevented with daily low-dose aspirin, starting before 16 weeks of gestation. By contrast, the prediction of term and postpartum pre-eclampsia is limited and there are no preventive treatments. Future research must investigate the pathogenesis of pre-eclampsia, in particular of term and postpartum pre-eclampsia, and evaluate new prognostic tests and treatments in adequately powered clinical trials.

Adverse events unlikely after fine-needle aspiration biopsies of thyroid nodules in patients on low-dose aspirin: a prospective controlled systematic single center analysis.

Our aim was to test the assertion that in terms of rate or severity level, adverse events (AEs) after fine-needle aspiration biopsies (FNABs) of thyroid nodules are unfazed by daily low-dose (100 mg) aspirin (acetylsalicylic acid, ASA) intake. We selected 268 patients for study, grouped as ASA-treated (PASA, n=78) or control (PCtrl, n=190) subjects. Controls received no antithrombotic medication. AE rates and severities were then analyzed based on patient- and nodule-related factors. We also compared group rates of non-diagnostic cytology results. AEs arising after FNABs (PASA, 5%; PCtrl, 8%) did not differ significantly by group in rate (p=0.4873) or severity level (p=0.3399). All were classifiable as minor incidents, none warranting any intervention. The data from the present study suggest, AEs after FNABs of thyroid nodules seldom occur and qualify as minor incidents. Such procedures may be safely conducted in patients taking daily low-dose ASA. There is no evidence to support preemptive therapeutic withdrawal.

Low-dose aspirin as primary prevention for adults without cardiovascular disease.

Cardiovascular disease is the leading cause of death in the United States. Patients with cardiovascular disease risk factors are often put on low-dose aspirin to prevent future cardiovascular events and cardiovascular death. However, the evidence supporting this practice is limited. To examine whether adults without a history of cardiovascular disease benefit from taking daily low-dose aspirin as primary prevention for cardiovascular disease and death. The four databases of PubMed, CINAHL, Scopus, and Ovid were used, and a total of 67 nonduplicate articles were reviewed. After examining those articles, four studies were included. Of the four studies, three were randomized controlled trials, and one was a retrospective cohort study. All four studies concluded that daily low-dose aspirin used for primary prevention does not lower the risk of death from cardiovascular disease. Further research needs to be conducted to determine whether daily low-dose aspirin is beneficial in individuals without a history of cardiovascular disease. Nurse practitioners need to know the most current evidence-based practice recommendations to appropriately counsel patients about whether they should be taking low-dose aspirin to prevent cardiovascular disease.

Daily Low-Dose Aspirin and Risk of Serious Falls and Fractures in Healthy Older People

Falls and fractures are frequent and deleterious to the health of older people. Aspirin has been reported to reduce bone fragility and slow bone loss. To determine if daily low-dose aspirin (100 mg) reduces the risk of fractures or serious falls (fall-related hospital presentations) in healthy older men and women. This substudy of a double-blind, randomized, placebo-controlled trial studied older adult men and women in 16 major sites across southeastern Australia. The ASPREE-FRACTURE substudy was conducted as part of the Australian component of the ASPREE trial. Between 2010 and 2014 healthy (free of cardiovascular disease, dementia or physical disability), community-dwelling volunteers aged 70 years or older were recruited to participate in the ASPREE trial. Potentially eligible participants were identified by medical practitioners and trial personnel and were then sent a letter of invitation to participate. Interested participants were screened for suitability. Eligible participants with medical practitioner authorization and adherent to a 4-week run-in medication trial were randomized. Data were analyzed from October 17, 2019, to August 31, 2022. Participants in the intervention group received a daily dose of oral 100 mg enteric-coated (low-dose) aspirin. The control group received a daily identical enteric-coated placebo tablet. The primary outcome of ASPREE-FRACTURE was the occurrence of any fracture. The secondary outcome was serious fall resulting in hospital presentation. In total, 16 703 people with a median (IQR) age of 74 (72-78) years were recruited, and 9179 (55.0%) were women. There were 8322 intervention participants and 8381 control participants included in the primary and secondary outcome analysis of 2865 fractures and 1688 serious falls over the median follow-up of 4.6 years. While there was no difference in the risk of first fracture between the intervention and control participants (hazard ratio, 0.97; 95% CI, 0.87-1.06; P = .50), aspirin was associated with a higher risk of serious falls (total falls 884 vs 804; incidence rate ratio, 1.17; 95% CI, 1.03-1.33; P = .01). Results remained unchanged in analyses that adjusted for covariates known to influence fracture and fall risk. In this substudy of a randomized clinical trial, the failure of low-dose aspirin to reduce the risk of fractures while increasing the risk of serious falls adds to evidence that this agent provides little favorable benefit in a healthy, White older adult population. This substudy is registered with the Australian New Zealand Clinical Trials Registry (ACTRN12615000347561).

Use of Daily Low-Dose Aspirin in Pregnancy for Women at High Risk of Preeclampsia at Georgetown Public Hospital Corporation

Objective: To Determine what proportion of eligible high-risk women diagnosed with preeclampsia received low dose aspirin during antepartum care. Design &amp; Methods: This was a retrospective chart review of all patients who delivered at Georgetown Public Hospital Corporation between September to December 2017 and were diagnosed with a hypertensive disorder in pregnancy. The primary outcome was the fraction of women diagnosed with preeclampsia, eclampsia or HELLP syndrome who met the U.S. Preventive Task Force criteria to be started on aspirin and were started on aspirin between 12 and 28 weeks of gestation. Maternal secondary outcomes included: Intensive care unit admissions, end organ injury, placental abruption and death. Neonatal secondary outcomes included: Neonatal intensive care unit admissions, fetal growth restriction, preterm births, stillbirths and neonatal death. Data was organised and analysed in Microsoft Excel 2016. Results: Of the 2,452 deliveries, 2,160 (88%) charts were found and reviewed. 14.3% were diagnosed with a hypertensive disorder in pregnancy. Of these, 37% had preeclampsia, eclampsia or HELLP syndrome. Among these, 36.8% met criteria to receive low dose aspirin antepartum but only 4.8% received aspirin. Of the secondary outcomes, one death occurred because of a haemorrhagic CVA. 42.1% of neonates were born prematurely of which 4 were stillbirths and 4 were neonatal deaths. Conclusions; The routine use of a low dose of aspirin among pregnant women who met the criteria to be started on was low. Recommendations: All women should be screened for the risk of developing preeclampsia and if needed, aspirin should be started between 12-28 weeks of gestation to get the best effects. Keywords: preeclampsia, aspirin in pregnancy, GPHC

Implementing subtype-specific pre-clinical models of breast cancer to study pre-treatment aspirin effects.

BackgorundPrior data suggest pre‐diagnostic aspirin use impacts breast tumour biology and patient outcome. Here, we employed faithful surgical resection models of HER2+ and triple‐negative breast cancer (TNBC), to study outcome and response mechanisms across breast cancer subtypes.MethodNOD/SCID mice were implanted with HER2+ MDA‐MB‐231/LN/2‐4/H2N, trastuzumab‐resistant HER2+ HCC1954 or a TNBC patient‐derived xenograft (PDX). A daily low‐dose aspirin regimen commenced until primary tumours reached ~250 mm3 and subsequently resected. MDA‐MB‐231/LN/2‐4/H2N mice were monitored for metastasis utilising imaging. To interrogate the survival benefit of pre‐treatment aspirin, 3 weeks post‐resection, HCC1954/TNBC animals received standard‐of‐care (SOC) chemotherapy for 6 weeks. Primary tumour response to aspirin was interrogated using immunohistochemistry.ResultsAspirin delayed time to metastasis in MDA‐MB‐231/LN/2‐4/H2N xenografts and decreased growth of HER2+/TNBC primary tumours. Lymphangiogenic factors and lymph vessels number were decreased in HER2+ tumours. However, no survival benefit was seen in aspirin pre‐treated animals (HCC1954/TNBC) that further received adjuvant SOC, compared with animals treated with SOC alone. In an effort to study mechanisms responsible for the observed reduction in lymphangiogenesis in HER2+ BC we utilised an in vitro co‐culture system of HCC1954 tumour cells and mesenchymal stromal cells (MSC). Aspirin abrogated the secretion of VEGF‐C in MSCs and also decreased the lymph/angiogenic potential of the MSCs and HCC1954 by tubule formation assay. Furthermore, aspirin decreased the secretion of uPA in HCC1954 cells potentially diminishing its metastatic capability.ConclusionOur data employing clinically relevant models demonstrate that aspirin alters breast tumour biology. However, aspirin may not represent a robust chemo‐preventative agent in the HER2+ or TNBC setting.

Use of Machine Learning to Estimate the Per-Protocol Effect of Low-Dose Aspirin on Pregnancy Outcomes

In randomized clinical trials (RCTs), per-protocol effects may be of interest in the presence of nonadherence with the randomized treatment protocol. Using machine learning in per-protocol effect estimation can help avoid model misspecification owing to strong parametric assumptions, as is common with standard methods (eg, logistic regression). To demonstrate the use of ensemble machine learning with augmented inverse probability weighting (AIPW) for per-protocol effect estimation in RCTs and to evaluate the per-protocol effect size of aspirin on pregnancy. This secondary analysis used data from 1227 women in the Effects of Aspirin in Gestation and Reproduction (EAGeR) trial, a multicenter, block-randomized, double-blind, placebo-controlled clinical trial of the effect of daily low-dose aspirin on pregnancy outcomes in women at high risk of pregnancy loss. Participants were recruited at 4 university medical centers in the US from June 15, 2007, to July 15, 2012. Women were followed up for 6 menstrual cycles for attempted pregnancy and 36 weeks of gestation if pregnancy occurred. Follow-up was completed on August 17, 2012. Data analyses were performed on July 9, 2021. Daily low-dose (81 mg) aspirin taken at least 5 of 7 days per week for at least 80% of follow-up time relative to placebo. Pregnancy detected using human chorionic gonadotropin (hCG) levels. Among the 1227 women included in the analysis (mean SD age, 28.74 [4.80] years), 1161 (94.6%) were non-Hispanic White and 858 (69.9%) adhered to the protocol. Five machine learning models were combined into 1 meta-algorithm, which was used to construct an AIPW estimator for the per-protocol effect. Compared with adhering to placebo, adherence to the daily low-dose aspirin protocol for at least 5 of 7 days per week was associated with an increase in the probability of hCG-detected pregnancy of 8.0 (95% CI, 2.5-13.6) more hCG-detected pregnancies per 100 women in the sample, which is substantially larger than the estimated intention-to-treat estimate of 4.3 (95% CI, -1.1 to 9.6) more hCG-detected pregnancies per 100 women in the sample. These findings suggest that a low-dose aspirin protocol is associated with increased hCG-detected pregnancy in women who adhere to treatment for at least 5 days per week. With the presence of nonadherence, per-protocol treatment effect estimates differ from intention-to-treat estimates in the EAGeR trial. The results of this secondary analysis of clinical trial data suggest that machine learning could be used to estimate per-protocol effects by adjusting for confounders related to nonadherence in a more flexible way than traditional regressions. ClinicalTrials.gov Identifier: NCT00467363.

A Pilot Study Of Aspirin Resistance In Obstructive Sleep Apnea Patients.

Purpose: Obstructive sleep apnea (OSA) leads to endothelial dysfunction and platelet hyperactivity, which are linked to increased risk of cardiovascular disease and implicated in the development of aspirin resistance. We hypothesized that aspirin resistance is prevalent among OSA patients and aimed to explore effects of continuous positive airway pressure (CPAP) therapy on aspirin responsiveness. Methods: In Phase 1, prevalence of aspirin resistance was determined cross-sectionally in a group of OSA patients (n=59) on daily low-dose aspirin (81 mg) taken before entering the study, for primary or secondary prevention. In Phase 2, aspirin responsiveness before and after initiation of CPAP therapy was compared and stratified by endothelial function in a cohort of aspirin-naïve patients with newly diagnosed OSA (n=18). Results: In Phase 1, prevalence of aspirin resistance was 17%; most patients (56%) were on CPAP therapy. In Phase 2, initiation of CPAP therapy was associated with significant improvement in endothelial function (p=0.03). The mean pre-CPAP aspirin resistance units (ARU) was 569 (SD=75). In subjects with endothelial dysfunction (44%), the mean decrease after initiation of CPAP therapy was 43 ARU (SD=81, p=0.18). In contrast, subjects with normal endothelial function experienced the mean decrease of 8 ARU (SD=116, p=0.83). Conclusion: Aspirin resistance may be prevalent among OSA patients. After initiation of CPAP therapy, we observed a trend towards improvement in aspirin responsiveness among patients with endothelial dysfunction. The role of endothelial dysfunction and aspirin resistance should be explored in further studies that focus on the effect of CPAP on cardiovascular outcomes.

Daily Low-Dose Aspirin, Diabetes, and Age—Still Looking for a Balance

Elizabeth Y. Liu, BA; Mohammed E. Al-Sofiani, MBBS, MSc; Hsin-Chieh Yeh, PhD; Justin B. Echouffo-Tcheugui, MD, PhD; Joshua J. Joseph, MD; Rita R. Kalyani, MD, MHS