Sex differences in platelet reactivity and response to low-dose aspirin therapy

Aspirin in Primary Prevention: Looking for Those Who Enjoy It

Based on a wealth of evidence, aspirin is one of the cornerstones of secondary prevention of cardiovascular disease. However, despite several studies showing efficacy also in primary prevention, an unopposed excess risk of bleeding leading to a very thin safety margin is evident in subjects without a clear acute cardiovascular event. Overall, the variability in recommendations from different scientific societies for aspirin use in primary prevention is a classic example of failure of simple risk stratification models based on competing risks (atherothrombosis vs. bleeding), perceived to be opposed but intertwined at the pathophysiological level. Notably, cardiovascular risk is dynamic in nature and cannot be accurately captured by scores, which do not always consider risk enhancers. Furthermore, the widespread use of other potent medications in primary prevention, such as lipid-lowering and anti-hypertensive drugs, might be reducing the benefit of aspirin in recent trials. Some authors, drawing from specific pathophysiological data, have suggested that specific subgroups might benefit more from aspirin. This includes patients with diabetes and those with obesity; sex-based differences are considered as well. Moreover, molecular analysis of platelet reactivity has been proposed. A beneficial effect of aspirin has also been demonstrated for the prevention of cancer, especially colorectal. This review explores evidence and controversies concerning the use of aspirin in primary prevention, considering new perspectives in order to provide a comprehensive individualized approach.

Global and regional burden of vaccine-induced thrombotic thrombocytopenia, 1969-2023: Comprehensive findings with critical analysis of the international pharmacovigilance database

OBJECTIVE

The scarcity of studies on vaccine-induced thrombosis and thrombocytopenia syndrome (TTS) limits the comprehensive understanding of vaccine safety on a global scale. Therefore, the objective of this study is to assess the global burden of vaccine-induced TTS, identify the vaccines most associated with it, and suggest clinical implications regarding vaccination.

METHODS

This study employed the World Health Organization international pharmacovigilance database, extracting records of vaccine-induced immune thrombotic thrombocytopenia from 1969 to 2023 (total reports, n > 130 million). Global reporting counts, reported odds ratios (ROR), and information components (IC) were calculated to identify the association between 19 vaccines and the occurrence of vaccine-induced TTS across 156 countries.

RESULTS

We identified 24 233 cases (male, n = 11 559 [47.7%]) of vaccine-induced TTS among 404 388 reports of all-cause TTS. There has been a significant increase in reports of vaccine-induced TTS events over time, with a noteworthy surge observed after 2020, attributed to cases of TTS associated with COVID-19 vaccines. Measles, mumps, and rubella (MMR) vaccines were associated with most TTS reports (ROR [95% confidence interval], 2.87 [2.75-3.00]; IC [IC0.25], 1.51 [1.43]), followed by hepatitis B (HBV, 2.23 [2.07-2.39]; 1.15 [1.03]), rotavirus diarrhea (1.95 [1.78-2.13]; 0.81 [0.53]), encephalitis (1.80 [1.50-2.16]; 0.84 [0.53]), hepatitis A (1.67 [1.50-1.86]; 0.73 [0.55]), adenovirus Type 5 vector-based (Ad5-vectored) COVID-19 (1.64 [1.59-1.68]; 0.69 [0.64]), pneumococcal (1.57 [1.49-1.66]; 0.65 [0.56]), and typhoid vaccines (1.41 [1.12-1.78]; 0.49 [0.11]). Concerning age and sex-specific risks, reports of vaccine-induced TTS were more associated with females and younger age groups. The age group between 12 and 17 years exhibited significant sex disproportion. Most of these adverse events had a short time to onset (days; mean [SD], 4.99 [40.30]) and the fatality rate was 2.20%, the highest rate observed in the age group over 65 years (3.79%) and lowest in the age group between 0 and 11 years (0.31%).

CONCLUSION

A rise in vaccine-induced TTS reports, notably MMR, HBV, and rotavirus diarrhea vaccines, was particularly related to young females. Ad5-vectored COVID-19 vaccines showed comparable or lower association with TTS compared to other vaccines. Despite the rarity of these adverse events, vigilance is essential as rare complications can be fatal, especially in older groups. Further studies with validated reporting are imperative to improve the accuracy of assessing the vaccine-induced TTS for preventive interventions and early diagnosis.

Genomic and phenotypic correlates of mosaic loss of chromosome Y in blood

Mosaic loss of Y (mLOY) is the most common somatic chromosomal alteration detected in human blood. The presence of mLOY is associated with altered blood cell counts and increased risk of Alzheimer's disease, solid tumors, and other age-related diseases. We sought to gain a better understanding of genetic drivers and associated phenotypes of mLOY through analyses of whole genome sequencing of a large set of genetically diverse males from the Trans-Omics for Precision Medicine (TOPMed) program. This approach enabled us to identify differences in mLOY frequencies across populations defined by genetic similarity, revealing a higher frequency of mLOY in the European American (EA) ancestry group compared to those of Hispanic American (HA), African American (AA), and East Asian (EAS) ancestry. Further, we identified two genes ( CFHR1 and LRP6 ) that harbor multiple rare, putatively deleterious variants associated with mLOY susceptibility, show that subsets of human hematopoietic stem cells are enriched for activity of mLOY susceptibility variants, and that certain alleles on chromosome Y are more likely to be lost than others.

Italian Association of Hospital Cardiologists Position Paper 'Gender discrepancy: time to implement gender-based clinical management'

It has been well assessed that women have been widely under-represented in cardiovascular clinical trials. Moreover, a significant discrepancy in pharmacological and interventional strategies has been reported. Therefore, poor outcomes and more significant mortality have been shown in many diseases. Pharmacokinetic and pharmacodynamic differences in drug metabolism have also been described so that effectiveness could be different according to sex. However, awareness about the gender gap remains too scarce. Consequently, gender-specific guidelines are lacking, and the need for a sex-specific approach has become more evident in the last few years. This paper aims to evaluate different therapeutic approaches to managing the most common women's diseases.

Sex dimorphisms in coagulation: Implications in trauma-induced coagulopathy and trauma resuscitation

Trauma-induced coagulopathy (TIC) is one of the leading causes of preventable death in injured patients. Consequently, it is imperative to understand the mechanisms underlying TIC and how to mitigate this mortality. An opportunity for advancement stems from the awareness that coagulation demonstrates a strong sex-dependent effect. Females exhibit a relative hypercoagulability compared to males, which persists after injury and confers improved outcomes. The mechanisms underlying sex dimorphisms in coagulation and its protective effect after injury have yet to be elucidated. This review explores sex dimorphisms in enzymatic hemostasis, fibrinogen, platelets, and fibrinolysis, with implications for resuscitation of patients with TIC.

Risk of postoperative bleeding after dental extraction in patients on antiplatelet therapy: systematic review and meta-analysis

OBJECTIVE

To determine the risk of bleeding after minor extraction in patients on different antiplatelet therapy (APT) regimens.

STUDY DESIGN

A search was conducted using PubMed and Google Scholar. Thirty-five papers were included in the systematic review, of which 23 papers provided the requisite information for meta-analysis. Subgroups were created based on the controls, as follows: (1) no control, (2) healthy control, and (3) interrupted APT control. In a meta-analysis, the studies were further subdivided into immediate and delayed bleeding.

RESULTS

No immediate or delayed bleeding risk was found in patients treated with aspirin vs healthy controls (relative risk [RR] = 1.26; P = .5 and RR = 2.17; P = .09, respectively). A higher immediate bleeding was recorded for patients on single nonaspirin APT vs those in the healthy population (RR = 3.72; P = .0009). A high risk of bleeding was recorded in patients receiving dual APT compared with healthy controls for immediate (RR = 10.3; P < .0001) and delayed (RR = 7.72; P = .001) bleeding. Dual APT continuation showed a higher risk of immediate bleeding (RR = 2.13) than interrupted APT, but the difference was insignificant (P = .07).

CONCLUSIONS

Dental extraction can be performed safely in patients on aspirin monotherapy. In contrast, patients receiving dual APT should be considered at risk for immediate and continued bleeding.

The impact of sex, body mass index and chronic kidney disease on outcomes following percutaneous coronary intervention

OBJECTIVE

This study sought to evaluate 1) the relationship between body mass index (BMI), chronic kidney disease (CKD) and bleeding complications in patients undergoing percutaneous coronary intervention (PCI); and 2) whether CKD modified the effect of BMI on major bleeding and major adverse cardiac and cerebrovascular events (MACCE).

BACKGROUND

The interaction of CKD, sex and BMI in patients undergoing PCI is unclear.

METHODS

Between 2010 and 2018, a total of 31,116 patients underwent PCI at six New York metropolitan area hospitals. Bleeding complications were classified by the Bleeding Academic Research Consortium (BARC). Major bleeding was defined as BARC≥3. MACCE was the composite of in-hospital death; myocardial infarction; cerebrovascular events and major bleeding complications. Interaction on multiplicative scales was assessed adjusting for other factors. A three-way multiplicative interaction between BMI, CKD and sex were considered and evaluated for both endpoints of primary interest (BARC≥3 and MACCE).

RESULTS

Patients with BARC≥3 bleeding were older (p < 0.0001) and more likely female (p < 0.0001). A 3-way interaction existed between sex, BMI, and CKD on BARC≥3 (p = 0.02). Specifically, the effect of CKD status on odds of BARC≥3 depended on BMI group among males, whereas BMI did modify the relationship between CKD and BARC≥3 among females; after stratification by sex, a significant interaction between BMI and CKD was present in females (p = 0.03) but not in males (p = 0.43). Among females without CKD, normal BMI patients had the greatest odds of BARC≥3 compared to obese or overweight females. Contrasted to females without CKD, among females with CKD there was no significant increased odds of BARC≥3 in normal BMI patients compared to obese or overweight females. However, overweight females with CKD had a significantly increased odds of BARC≥3 compared to obese females with CKD. Furthermore, obese females with CKD had significantly greater BARC≥3 odds compared to obese females without CKD. Similarly, overweight females with CKD had an increased odds of BARC≥3 compared to overweight females without CKD. No significant interactions were found for the odds of MACCE.

CONCLUSION

In patients undergoing PCI, there was evidence of a significant and complex 3-way interaction between BMI, CKD and sex for major bleeding events. The predicted probability of major bleeding was greater for females than for male patients, and for both sexes, greater among those with CKD, but BMI group influences these probabilities. Obese females with kidney disease had the lowest incidence of bleeding complications when compared with overweight or normal weight female patients undergoing PCI. This interaction was not seen in the male group or for MACCE. Furthermore, age, cardiogenic shock, STEMI and use of IABP/Impella were each independently associated with odds of major bleeding (among both males and females) and MACCE.

Sex-Specific Acute Cerebrovascular Responses to Photothrombotic Stroke in Mice

Mechanisms underlying cerebrovascular stroke outcomes are poorly understood, and the effects of biological sex on cerebrovascular regulation post-stroke have yet to be fully comprehended. Here, we explore the overlapping roles of gonadal sex hormones and rho-kinase (ROCK), two important modulators of cerebrovascular tone, on the acute cerebrovascular response to photothrombotic (PT) focal ischemia in mice. Male mice were gonadectomized and female mice were ovariectomized to remove gonadal hormones, whereas control ("intact") animals received a sham surgery prior to stroke induction. Intact wild-type (WT) males showed a delayed drop in cerebral blood flow (CBF) compared with intact WT females, whereby maximal CBF drop was observed 48 h following stroke. Gonadectomy in males did not alter this response. However, ovariectomy in WT females produced a "male-like" phenotype. Intact Rock2+/- males also showed the same phenotypic response, which was not altered by gonadectomy. Alternatively, intact Rock2+/- females showed a significant difference in CBF values compared with intact WT females, displaying higher CBF values immediately post-stroke and showing a maximal CBF drop 48 h post-stroke. This pattern was not altered by ovariectomy. Altogether, these data illustrate sex differences in acute CBF responses to PT stroke, which seem to involve gonadal female sex hormones and ROCK2. Overall, this study provides a framework for exploring sex differences in acute CBF responses to focal ischemic stroke in mice.

Sex, Endothelial Cell Functions, and Peripheral Artery Disease

Peripheral artery disease (PAD) is caused by blocked arteries due to atherosclerosis and/or thrombosis which reduce blood flow to the lower limbs. It results in major morbidity, including ischemic limb, claudication, and amputation, with patients also suffering a heightened risk of heart attack, stroke, and death. Recent studies suggest women have a higher prevalence of PAD than men, and with worse outcomes after intervention. In addition to a potential unconscious bias faced by women with PAD in the health system, with underdiagnosis, and lower rates of guideline-based therapy, fundamental biological differences between men and women may be important. In this review, we highlight sexual dimorphisms in endothelial cell functions and how they may impact PAD pathophysiology in women. Understanding sex-specific mechanisms in PAD is essential for the development of new therapies and personalized care for patients with PAD.

Appraising features and outlook of women and men discharged after an acute coronary syndrome: evidence from the 23,700-patient PRAISE International Registry

BACKGROUND

Acute coronary syndromes (ACS) are a common cause of morbidity and mortality. Several studies have focused on ACS at admission, but limited evidence is available on sex-based comparison of patients discharged after ACS. We appraised the outlook of women and men discharged after ACS.

METHODS

Details on women enrolled in the PRAISE registry, an international cohort study spanning 23,700 patients included between 2003 and 2019, were systematically collected. We focused on patient and procedural features, medications at discharge, and 1-year outcomes. The primary endpoint was the composite of death, myocardial infarction, or major bleeding after discharge.

RESULTS

A total of 17,804 (76.5%) men and 5466 (23.5%) women were included. Several baseline differences were found, including risk factors and prior revascularization (all P<0.05). Men underwent more frequently radial access, and at discharge they received more commonly dual antiplatelet therapy and guideline-directed medical therapy (P<0.001). At 1-year follow-up, risks of death, reinfarction, major bleeding, and non-fatal major bleeding, jointly or individually, were all significantly higher in women (all P≤0.01). All such differences however did not hold true at multivariable analysis, with the exception of major bleeding, which appeared surprisingly less common in females at fully adjusted analysis (P=0.017).

CONCLUSIONS

Women, albeit only apparently, had worse outcomes 1 year after discharge for ACS, but adjusted analysis suggested instead that they faced a lower risk of major bleeding after discharge. These findings support the call for more aggressive management of women after ACS.

Mosaic chromosomal alterations in blood across ancestries using whole-genome sequencing

Megabase-scale mosaic chromosomal alterations (mCAs) in blood are prognostic markers for a host of human diseases. Here, to gain a better understanding of mCA rates in genetically diverse populations, we analyzed whole-genome sequencing data from 67,390 individuals from the National Heart, Lung, and Blood Institute Trans-Omics for Precision Medicine program. We observed higher sensitivity with whole-genome sequencing data, compared with array-based data, in uncovering mCAs at low mutant cell fractions and found that individuals of European ancestry have the highest rates of autosomal mCAs and the lowest rates of chromosome X mCAs, compared with individuals of African or Hispanic ancestry. Although further studies in diverse populations will be needed to replicate our findings, we report three loci associated with loss of chromosome X, associations between autosomal mCAs and rare variants in DCPS, ADM17, PPP1R16B and TET2 and ancestry-specific variants in ATM and MPL with mCAs in cis.

Sex Differences in Patients With Cryptogenic Cerebrovascular Events Undergoing Transcatheter Closure of Patent Foramen Ovale

Background Scarce data exist on sex differences in patients with cryptogenic cerebrovascular events undergoing patent foramen ovale (PFO) closure. This study aimed to determine the sex differences in clinical profile, procedural characteristics, and long-term outcomes of patients with cryptogenic cerebrovascular events undergoing PFO closure. Methods and Results A retrospective cohort was used, including 1076 consecutive patients undergoing PFO closure because of a cryptogenic cerebrovascular event. Patients were divided into 2 groups: 469 (43.6%) women and 607 (56.4%) men. The median follow-up was 3 years (interquartile range, 2-8 years). Women were younger (46±13 versus 50±12 years; P<0.01) and had a higher risk of paradoxical embolism score (6.9±1.7 versus 6.6±1.6; P<0.01). Procedural characteristics and postprocedural antithrombotic therapy were similar. At follow-up, there were no differences in atrial fibrillation (women versus men: 0.47 versus 0.97 per 100 patient-years; incidence rate ratio [IRR], 0.55 [95% CI, 0.27-1.11]; P=0.095; adjusted P=0.901), stroke (0.17 versus 0.07 per 100 patient-years; IRR, 2.58 [95% CI, 0.47-14.1]; P=0.274; adjusted P=0.201), or transient ischemic attack (0.43 versus 0.18 per 100 patient-years; IRR, 2.58 [95% CI, 0.88-7.54]; P=0.084; adjusted P=0.121); nevertheless, women exhibited a higher incidence of combined ischemic cerebrovascular events (0.61 versus 0.26 per 100 patient-years; IRR, 2.58 [95% CI, 1.04-6.39]; P=0.041; adjusted P=0.028) and bleeding events (1.04 versus 0.45 per 100 patient-years; IRR, 2.82 [95% CI, 1.41-5.65]; P=0.003; adjusted P=0.004). Conclusions Compared with men, women with cryptogenic cerebrovascular events undergoing PFO closure were younger and had a higher risk of paradoxical embolism score. After a median follow-up of 3 years, there were no differences in stroke events, but women exhibited a higher rate of combined (stroke and transient ischemic attack) cerebrovascular events and bleeding complications. Additional studies are warranted to clarify sex-related outcomes after PFO closure further.

Gender differences in efficacy and safety of antiplatelet strategies for acute coronary syndromes

INTRODUCTION

Dual antiplatelet therapy (DAPT) represents the cornerstone of secondary prevention in patients presenting with acute coronary syndrome (ACS) and undergoing percutaneous coronary intervention. Despite its undisputed efficacy in reducing thrombotic events, DAPT increases the risk of bleeding, which is associated with higher morbidity and mortality. Novel antiplatelet strategies (i.e. in terms of timing, selection of drugs and their combinations, and modulation strategies) have been tested in randomized trials, suggesting the utility of tailored approaches in selected populations (i.e. patients at high bleeding or ischemic risk). It remains uncertain whether the effect of these strategies is influenced by sex.

AREAS COVERED

This narrative review provides an overview of available evidence surrounding sex differences in the efficacy and safety of antiplatelet strategies for ACS and analyzes the potential reasons behind these findings. Relevant content was searched for in PubMed.

EXPERT OPINION

Significant differences between women and men exist in terms of clinical presentation, pharmacotherapies, interventional management, and prognosis of ACS. However, these observations do not appear to be attributed to different pharmacodynamic effects of antiplatelet therapies between women and men. Unfortunately, a critical issue depends on women being often underrepresented in clinical trials, leading to a substantial lack of sex-specific evidence.

Sex Differences in Outcomes After Transcatheter Aortic Valve Replacement: A POPular TAVI Subanalysis

BACKGROUND

Stroke and bleeding are complications after transcatheter aortic valve replacement (TAVR). A higher incidence of bleeding and stroke has been reported in women, but the role of antithrombotic management pre- and post-TAVR has not been studied.

OBJECTIVES

The study sought to compare bleeding and ischemic complications after TAVR between women and men stratified by antiplatelet and oral anticoagulant (OAC) regimen.

METHODS

The POPular TAVI (Antiplatelet Therapy for Patients Undergoing Transcatheter Aortic Valve Implantation) trial was a randomized clinical trial to test the hypothesis that monotherapy with aspirin or OAC after TAVR is safer than the addition of clopidogrel. The primary endpoints of interest of this post hoc subanalysis were: 1) all bleeding; and 2) a composite of ischemic events consisting of stroke and myocardial infarction. Secondary endpoints were: 1) nonprocedural bleeding; 2) major or life-threatening bleeding; 3) minor bleeding; 4) stroke; 5) myocardial infarction; and 6) all-cause death.

RESULTS

A total of 978 patients (466 [47.6%] women) were included in this study. All bleeding and the composite of myocardial infarction and stroke rates were similar between sexes (all bleeding: 106 [22.8%] women vs 121 [23.6%] men; P = 0.815; ischemic events: 26 [5.6%] vs 36 [7.0%]; P = 0.429). However, major or life-threatening bleeding occurred more often in women (58 [12.5%]) vs men (38 [7.4%]) (P = 0.011), most of which were access site bleedings. The use of aspirin pre- and post-TAVR increased major or life-threatening bleeding in women but not in men.

CONCLUSIONS

After TAVR, overall bleeding and ischemic outcomes were similar between women and men. However, women had more major or life-threatening bleedings, especially those receiving aspirin pre- and post-TAVR.

Low-dose aspirin in the primary prevention of cardiovascular diseases: A retrospective, propensity score matched study

BACKGROUND AND AIMS

Although the guidelines have been revised recently, the effect of aspirin for the primary prevention of cardiovascular disease (CVD) is still controversial. Thus, we aimed to evaluate the effect of aspirin on primary prevention in the real world.

METHODS

Among the 4,266,268 participants without a history of CVD or previous prescription of aspirin and other antiplatelet agents who were screened between 2002 and 2008, 268,963 persons who were prescribed low-dose aspirin (≤100 mg/day) over 90 days in 2002-2008 and 1,075,852 persons who did not receive aspirin were selected after propensity score matching. A Cox proportional-hazards model was used to evaluate the effect of low-dose aspirin on the development of CVD and bleeding episodes.

RESULTS

Aspirin showed a protective effect on total CVD events (hazard ratio (HR); 0.737, 95% confidence interval; 0.729-0.745). The protective effect of aspirin on total CVD events was significant in men, women and even in young participants (<65 years). Aspirin had a protective effect in participants with diabetes or hypertension against all subcategories of CVD. The HR of bleeding risk was 1.4-1.5 in aspirin group.

CONCLUSIONS

Low-dose aspirin generally showed a protective effect against CVD regardless of age, sex, and underlying comorbidities in the real world. Though, the effect of aspirin was evident at a young age, the risk of bleeding was also high (1.4-1.5 times), and thus, careful prescription is required.

Expression of microRNA Predicts Cardiovascular Events in Patients with Stable Coronary Artery Disease

BACKGROUND

 New biomarkers are warranted to identify patients with coronary artery disease (CAD) at high risk of recurrent cardiovascular events. It has been reported that the expression of microRNAs (miRs) may influence the development of CAD.

OBJECTIVES

 We aimed to investigate whether the expression of selected candidate miRs is a predictor of cardiovascular events in a cohort of stable CAD patients.

METHODS

 We performed a single-center prospective study of 749 stable CAD patients with a median follow-up of 2.8 years. We investigated the expression of nine candidate miRs and their relation to cardiovascular events in this cohort. The primary endpoint was the composite of nonfatal myocardial infarction (MI), stent thrombosis (ST), ischemic stroke, and cardiovascular death. The composite of nonfatal MI and ST was analyzed as a secondary endpoint. Furthermore, nonfatal MI, ST, ischemic stroke, and all-cause mortality were analyzed as individual endpoints.

RESULTS

 Employing receiver operating characteristic curves, it was shown that compared with traditional cardiovascular risk factors alone, combining the expression of miR-223-3p with existing traditional cardiovascular risk factors increased the predictive value of ST (area under the curve: 0.88 vs. 0.77, p = 0.04), the primary composite endpoint (0.65 vs. 0.61, p = 0.049), and the secondary endpoint of the composite of nonfatal MI and ST (0.68 vs. 0.62, p = 0.04).

CONCLUSION

 Among patients with CAD, adding miR-223-3p expression to traditional cardiovascular risk factors may improve prediction of cardiovascular events, particularly ST. Clinical trials confirming these findings are warranted.

Whole genome sequencing identifies structural variants contributing to hematologic traits in the NHLBI TOPMed program

Genome-wide association studies have identified thousands of single nucleotide variants and small indels that contribute to variation in hematologic traits. While structural variants are known to cause rare blood or hematopoietic disorders, the genome-wide contribution of structural variants to quantitative blood cell trait variation is unknown. Here we utilized whole genome sequencing data in ancestrally diverse participants of the NHLBI Trans Omics for Precision Medicine program (N = 50,675) to detect structural variants associated with hematologic traits. Using single variant tests, we assessed the association of common and rare structural variants with red cell-, white cell-, and platelet-related quantitative traits and observed 21 independent signals (12 common and 9 rare) reaching genome-wide significance. The majority of these associations (N = 18) replicated in independent datasets. In genome-editing experiments, we provide evidence that a deletion associated with lower monocyte counts leads to disruption of an S1PR3 monocyte enhancer and decreased S1PR3 expression.

Gender-differences in antithrombotic therapy across the spectrum of ischemic heart disease: Time to tackle the Yentl syndrome?

The incidence and clinical presentation of ischemic heart disease (IHD), as well as thrombotic and bleeding risks, appear to differ between genders. Compared with men, women feature an increased thrombotic risk, probably related to an increased platelet reactivity, higher level of coagulation factors, and sex-associated unique cardiovascular risk factors, such as pregnancy-related (i.e., pre-eclampsia and gestational diabetes), gynecological disorders (i.e., polycystic ovary syndrome, early menopause) and autoimmune or systemic inflammatory diseases. At the same time, women are also at increased risk of bleeding, due to inappropriate dosing of antithrombotic agents, smaller blood vessels, lower body weight and comorbidities, such as diabetes and chronic kidney disease. Pharmacological strategies focused on the personalization of antithrombotic treatment may, therefore, be particularly appealing in women in light of their higher bleeding and ischemic risks. Paradoxically, although women represent a large proportion of cardiovascular patients in our practice, adequate high-quality clinical trial data on women remain scarce and inadequate to guide decision-making processes. As a result, IHD in women tends to be understudied, underdiagnosed and undertreated, a phenomenon known as a "Yentl syndrome." It is, therefore, compelling for the scientific community to embark on dedicated clinical trials to address underrepresentation of women and to acquire evidence-based knowledge in the personalization of antithrombotic therapy in women.

Sex-Related Differences in Thrombus Burden in STEMI Patients Undergoing Primary Percutaneous Coronary Intervention

BACKGROUND

Women have a worse prognosis after ST-segment elevation myocardial infarction (STEMI) than men. The prognostic role of thrombus burden (TB) in influencing the sex-related differences in clinical outcomes after STEMI has not been clearly investigated.

OBJECTIVES

The aim of this study was to assess the sex-related differences in TB and its clinical implications in patients with STEMI.

METHODS

Individual patient data from the 3 major randomized clinical trials of manual thrombus aspiration were analyzed, encompassing a total of 19,047 patients with STEMI, of whom 13,885 (76.1%) were men and 4,371 (23.9%) were women. The primary outcome of interest was 1-year cardiovascular (CV) death. The secondary outcomes of interest were recurrent myocardial infarction, heart failure, all-cause mortality, stroke, stent thrombosis (ST), and target vessel revascularization at 1 year.

RESULTS

Patients with high TB (HTB) had worse 1-year outcomes compared with those presenting with low TB (adjusted HR for CV death: 1.52; 95% CI: 1.10-2.12; P = 0.01). In unadjusted analyses, female sex was associated with an increased risk for 1-year CV death regardless of TB. After adjustment, the risk for 1-year CV death was higher only in women with HTB (HR: 1.23; 95% CI: 1.18-1.28; P < 0.001), who also had an increased risk for all-cause death and ST than men.

CONCLUSIONS

In patients with STEMI, angiographic evidence of HTB negatively affected prognosis. Among patients with HTB, women had an excess risk for ST, CV, and all-cause mortality than men. Further investigations are warranted to better understand the pathophysiological mechanisms leading to excess mortality in women with STEMI and HTB.

Sex-Related Differences in Platelet Aggregation: A Literature Review Supplemented with Local Data from a Group of Generally Healthy Individuals

The process of platelet aggregation is often influenced by several factors including sex and age. A literature review confirmed the existence of sex-related differences in platelet aggregation. Although 68 out of 78 papers found such differences, there are still some controversies regarding these differences, which can be due to multiple factors (age, trigger, concomitant disease, sample handling, etc.). These outcomes are discussed in line with novel results obtained from a local study, in which blood samples from a total of 53 overall healthy women and men with ages ranging from 20 to 66 years were collected. Aggregation was induced with seven different triggers (ristocetin, thrombin receptor activating peptide 6 [TRAP-6], arachidonic acid [AA], platelet-activating factor 16 [PAF-16], ADP, collagen, or thromboxane A₂ analog U-46619) ex vivo. In addition, three FDA-approved antiplatelet drugs (vorapaxar, ticagrelor, or acetylsalicylic acid [ASA]) were also tested. In general, women had higher aggregation responses to some agonists (ADP, TRAP), as well as lower benefit from inhibitors (ASA, vorapaxar). The aggregatory responses to AA and TRAP decreased with age in both sexes, while responses to ADP, U-46619, and PAF were affected by age only in women. In conclusion, more studies are needed to decipher the biological importance of sex-related differences in platelet aggregation in part to enable personalized antiplatelet treatment.

Sex differences at the platelet-vascular interface

Platelets are multifunctional cells that ensure the integrity of the vascular wall and modulate the immune response at the blood/vascular interface. Their pathological activation results in both thrombosis and inflammation and implicates them in the pathogenesis of vascular disease. Vascular diseases are sexually dimorphic in terms of incidence, clinical presentation, outcome, and efficacy of anti-platelet therapy. We here provide an overview of what is known about the role of platelets in the initiation and progression of vascular diseases and summarize what is known about the sex differences in platelet reactivity and in the thromboinflammatory mechanisms that drive these diseases, with a particular focus on atherosclerosis, obstructive and non-obstructive coronary artery disease, and ischemic stroke. Understanding the sex differences at the platelet-vascular interface is clinically relevant as it will enable: (1) to design new therapeutic strategies that prevent the detrimental effects of the immune-modulatory function of platelets taking sex into account, and (2) to evaluate if sex-specific anti-platelet drug regimens should be used to reduce the risk not only of thrombosis but also of vascular disease progression.

The impact of PEAR 1 polymorphism on clinical outcomes in Chinese patients receiving dual antiplatelet therapy after percutaneous coronary intervention

Background: Patients might still experience major adverse cardiovascular events even with dual antiplatelet therapy after percutaneous coronary intervention. Our study aimed to explore the impact of gene polymorphism on clinical outcomes in one-year follow-up. Methods: A total of 171 patients treated with dual antiplatelet therapy after percutaneous coronary intervention from April to December 2020 in the first hospital of Jilin University enrolled in this study. Results: PEAR1 genetic polymorphisms was associated with the arachidonic acid (AA) and adenosine diphosphate (ADP) platelet aggregation. Hyperglycemia was associated with the rate of major adverse cardiovascular events. PEAR1 GA+AA genetic genetic polymorphisms is associated with hyperglycemia. Conclusion: PEAR1 GG is a risk factor for AA and ADP platelet aggregation. Hyperglycemia can effect the one-year outcome. PEAR1 GA+AA genetic polymorphisms are associated with hyperglycemia.

Thromboelastography-Based Evaluation of Gender-Associated Hypercoagulability

BACKGROUND

Age, race, and gender differences in coagulation status of healthy volunteers have been reported in previous case series; however, rigorous multivariate analysis adjusting for these factors is lacking. We aimed to investigate the effects of age, race, and gender on baseline coagulation status in healthy volunteers.

METHODS

Thirty healthy volunteer controls with no history of bleeding or thrombotic events and no previous anticoagulant or antiplatelet use were recruited. Citrated and heparinized blood samples were drawn, and kaolin and platelet-mapping thromboelastography (TEG) assays performed.

RESULTS

Thirty participants had a mean age of 37, mean body mass index of 29 kg/m², and were 47% African-American and 70% female. Women were significantly older than men (40 ± 11 y vs 28 ± 7 y, P = .002); there were no significant differences in demographics by race. Multivariate analysis of variance for the effect of age, race, and gender across TEG parameters yielded evidence for gender differences in hypercoagulability (Pillai's trace P = .02), which appear to be driven by differences in K-time, alpha angle, maximal amplitude, and G parameter. Women were hypercoagulable compared to men, as manifested by shorter K-time, steeper alpha angle, higher maximal amplitude, and larger G parameter.

DISCUSSION

Women at baseline have relatively hypercoagulable fibrin deposition kinetics, platelet contributions to clot formation, and overall clot strength compared to men, even when adjusted for age and race. Additional research is needed to specifically detail the key patient-level factors, clinical implications, and opportunities for tailored therapy related to gender-associated hypercoagulability.

Sex-Related Outcomes of Medical, Percutaneous, and Surgical Interventions for Coronary Artery Disease: JACC Focus Seminar 3/7

Biological and sociocultural differences between men and women are complex and likely account for most of the variations in the epidemiology and treatment outcomes of coronary artery disease (CAD) between the 2 sexes. Worse outcomes in women have been described following both conservative and invasive treatments of CAD. For example, increased levels of residual platelet reactivity during treatment with antiplatelet drugs, higher rates of adverse cardiovascular outcomes following percutaneous coronary revascularization, and higher operative and long-term mortality after coronary bypass surgery have been reported in women compared with in men. Despite the growing recognition of sex-specific determinants of outcomes, representation of women in clinical studies remains low and sex-specific management strategies are generally not provided in guidelines. This review summarizes the current evidence on sex-related differences in patients with CAD, focusing on the differential outcomes following medical therapy, percutaneous coronary interventions, and coronary artery bypass surgery.

Secondary analyses for genome-wide association studies using expression quantitative trait loci

Genome-wide association studies (GWAS) have successfully identified thousands of single nucleotide polymorphisms (SNPs) associated with complex traits; however, the identified SNPs account for a fraction of trait heritability, and identifying the functional elements through which genetic variants exert their effects remains a challenge. Recent evidence suggests that SNPs associated with complex traits are more likely to be expression quantitative trait loci (eQTL). Thus, incorporating eQTL information can potentially improve power to detect causal variants missed by traditional GWAS approaches. Using genomic, transcriptomic, and platelet phenotype data from the Genetic Study of Atherosclerosis Risk family-based study, we investigated the potential to detect novel genomic risk loci by incorporating information from eQTL in the relevant target tissues (i.e., platelets and megakaryocytes) using established statistical principles in a novel way. Permutation analyses were performed to obtain family-wise error rates for eQTL associations, substantially lowering the genome-wide significance threshold for SNP-phenotype associations. In addition to confirming the well known association between PEAR1 and platelet aggregation, our eQTL-focused approach identified a novel locus (rs1354034) and gene (ARHGEF3) not previously identified in a GWAS of platelet aggregation phenotypes. A colocalization analysis showed strong evidence for a functional role of this eQTL.

Sex-Dependent Effect of Platelet Nitric Oxide: Production and Platelet Reactivity in Healthy Individuals

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Platelet reactivity is greater in healthy women compared with men.

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Following an oral nitrate load, platelet nitric oxide production increased disproportionately more in healthy women than healthy men with attenuated platelet reactivity in women and enhanced platelet reactivity in men.

A nitrate-rich diet has many cardiovascular benefits, but the mechanism behind this is unclear. We hypothesized that the ingestion of nitrate augments nitrate to nitrite reduction, leading to nitric oxide (NO) production, which may suppress platelet reactivity. In a randomized, double-blinded, placebo-controlled study involving healthy individuals, ingestion of nitrate augmented saliva and plasma nitrite/nitrate concentration and enhanced platelet NO production disproportionately in women compared with men. The response of elevated platelet NO in men was increased platelet reactivity and the response of markedly elevated platelet NO in women slightly inhibited platelet reactivity.

Whole-genome sequencing in diverse subjects identifies genetic correlates of leukocyte traits: The NHLBI TOPMed program

Many common and rare variants associated with hematologic traits have been discovered through imputation on large-scale reference panels. However, the majority of genome-wide association studies (GWASs) have been conducted in Europeans, and determining causal variants has proved challenging. We performed a GWAS of total leukocyte, neutrophil, lymphocyte, monocyte, eosinophil, and basophil counts generated from 109,563,748 variants in the autosomes and the X chromosome in the Trans-Omics for Precision Medicine (TOPMed) program, which included data from 61,802 individuals of diverse ancestry. We discovered and replicated 7 leukocyte trait associations, including (1) the association between a chromosome X, pseudo-autosomal region (PAR), noncoding variant located between cytokine receptor genes (CSF2RA and CLRF2) and lower eosinophil count; and (2) associations between single variants found predominantly among African Americans at the S1PR3 (9q22.1) and HBB (11p15.4) loci and monocyte and lymphocyte counts, respectively. We further provide evidence indicating that the newly discovered eosinophil-lowering chromosome X PAR variant might be associated with reduced susceptibility to common allergic diseases such as atopic dermatitis and asthma. Additionally, we found a burden of very rare FLT3 (13q12.2) variants associated with monocyte counts. Together, these results emphasize the utility of whole-genome sequencing in diverse samples in identifying associations missed by European-ancestry-driven GWASs.

Leveraging the Genetic Diversity of Human Stem Cells in Therapeutic Approaches

Since their discovery 15 years ago, human pluripotent stem cell (hPSC) technologies have begun to revolutionize science and medicine, rapidly expanding beyond investigative research to drug discovery and development. Efforts to leverage hPSCs over the last decade have focused on increasing both the complexity and in vivo fidelity of human cellular models through enhanced differentiation methods. While these evolutions have fostered novel insights into disease mechanisms and influenced clinical drug discovery and development, there are still several considerations that limit the utility of hPSC models. In this review, we highlight important, yet underexplored avenues to broaden their reach. We focus on (i) the importance of diversifying existing hPSC collections, and their utilization to investigate therapeutic strategies in individuals from different genetic backgrounds, ancestry and sex; (ii) considerations for the selection of therapeutically relevant hPSC-based models; (iii) strategies to adequately increase the scale of cell-based studies; and (iv) the advances and constraints of clinical trials in a dish. Moreover, we advocate for harnessing the translational capabilities of hPSC models along with the use of innovative, scalable approaches for understanding genetic biases and the impact of sex and ancestry on disease mechanisms and drug efficacy and response. The next decade of hPSC innovation is poised to provide vast insights into the genetic basis of human disease and enable rapid advances to develop, repurpose, and ensure the safety of the next generation of disease therapies across diverse human populations.

Female Gender is a Predictor of Lower Iliac Vein Stenting Patency Rates

BACKGROUND

Iliac venous stenting (IVS) for thrombotic and nonthrombotic venous disease is increasingly used as evidence of the safety, efficacy and durability of these interventions increases. Female gender has been implicated as a predictor of failure in arterial endovascular interventions. We hypothesize that female gender could be predictive of patency rates of iliac vein stenting.

METHODS

Consecutive patients who underwent IVS for thrombotic or nonthrombotic venous disease at our institution from 2007 until 2019 were identified and divided into groups based on gender. Operative notes, venograms, and the electronic health record were then queried to obtain operative details, co-morbid conditions, postoperative outcomes and stent patency. Study outcome was long term patency rate. The data was analyzed using chi-square, logistic regression, and Kaplan-Meier analysis as appropriate.

RESULTS

A total of 200 consecutive patients (231 limbs) were identified in our retrospective analysis, with a mean age of 48.8 ± 17.3, and BMI of 31.6 ± 8.6. Of those, 119 (59.5%) patients, (131 [56.8%] limbs) were female. Comparisons between the gender groups revealed no difference in age, BMI, or preoperative comorbidities. There was no difference in type of venous disease between male (85% thrombotic, 15% nonthrombotic) and female (84% thrombotic, 16% nonthrombotic), P= 0.830. The male cohort was more likely to present with leg ulceration (17% vs. 4.6%, P = 0.002), and the female cohort was more likely to present with leg edema (98.5% vs. 93.0%, P= 0.03). The male cohort had a higher rate of caval (48% vs. 33.6%, P= 0.027) and infrainguinal stent extension. (11% vs. 6.9%, P= 0.02). Females had a higher rate of left sided stenting (80.9% vs. 66/0%, P= 0.010). There was no difference in the median stent diameter used between the cohorts. Primary patency at 5 years was significantly higher for the male cohort (94.1% vs. 74.4%, P= 0.01) On adjusted multivariable cox regression female gender was a predictor of loss of primary patency within 5 years (HR, 4.04; P= 0.007).

CONCLUSIONS

In this single center retrospective analysis of IVS, male patients were found to have better primary stent patency compared to female.

Female gender is associated with increased late luminal narrowing within the stent graft after thoracic endovascular aortic repair

BACKGROUND

Luminal narrowing, suspected secondary to thrombus, occurs within stent grafts at an unclear incidence after thoracic endovascular aortic repair (TEVAR). The significance of this phenomenon has not been determined, nor have the risk factors for development of intragraft luminal narrowing. Small graft diameter is hypothesized to be a risk factor for the development of ingraft stenosis.

METHODS

A retrospective analysis was performed of a multicenter healthcare system including all patients who underwent TEVAR between July 2011 and July 2019 with at least 1 year of subsequently available surveillance contrast-enhanced computed tomography imaging. Standard demographic, preoperative, intraoperative, and postoperative variables were collected. Measurements were obtained via direct off-line images from computed tomography scans. Patent intragraft diameters were compared with baseline and interval change values were normalized to time to follow-up. The primary outcome measure was annual rate of intragraft luminal narrowing.

RESULTS

There were 208 patients who met the inclusion criteria (94 women, 114 men) with a median follow-up of 822 days. The mean annual rate of percent intragraft diameter reduction was 10.5 ± 7.7% for women and 7.6 ± 5.6% for men (P = .0026). Multivariate analysis demonstrated female gender (P = .0283), preoperative diagnosis of hypertension (P = .0449), and need for coverage of the left subclavian artery (P = .0328) were all significant predictors of intragraft luminal narrowing. Small aortic diameters were not found to be associated independently with ingraft luminal narrowing nor was the concomitant use of antiplatelet or anticoagulation medications. Significant amounts of ingraft luminal narrowing, defined as a greater than 20% intragraft diameter decrease, were associated with an increased need for any reintervention, including for malperfusion, endoleak, and symptomatic aneurysm (P = .0249). Kaplan-Meier estimates demonstrated a significant gender-associated difference in high rates of intragraft luminal narrowing (P = .00189).

CONCLUSIONS

In this analysis, female gender is shown to be a significant nonmodifiable risk factor for intragraft luminal narrowing after TEVAR. The development of this phenomenon is not benign; as such, these findings were associated with an increased need for reintervention. This finding may be attributable to differences in aortic compliance or gender-associated differences in coagulation pathways and merits further investigation. Surveillance after thoracic stent grafting must account for patient-specific variations in complication risk.

Gene and protein expression in human megakaryocytes derived from induced pluripotent stem cells

BACKGROUND

There is interest in deriving megakaryocytes (MKs) from pluripotent stem cells (iPSC) for biological studies. We previously found that genomic structural integrity and genotype concordance is maintained in iPSC-derived MKs.

OBJECTIVE

To establish a comprehensive dataset of genes and proteins expressed in iPSC-derived MKs.

METHODS

iPSCs were reprogrammed from peripheral blood mononuclear cells (MNCs) and MKs were derived from the iPSCs in 194 healthy European American and African American subjects. mRNA was isolated and gene expression measured by RNA sequencing. Protein expression was measured in 62 of the subjects using mass spectrometry.

RESULTS AND CONCLUSIONS

MKs expressed genes and proteins known to be important in MK and platelet function and demonstrated good agreement with previous studies in human MKs derived from CD34+ progenitor cells. The percent of cells expressing the MK markers CD41 and CD42a was consistent in biological replicates, but variable across subjects, suggesting that unidentified subject-specific factors determine differentiation of MKs from iPSCs. Gene and protein sets important in platelet function were associated with increasing expression of CD41/42a, while those related to more basic cellular functions were associated with lower CD41/42a expression. There was differential gene expression by the sex and race (but not age) of the subject. Numerous genes and proteins were highly expressed in MKs but not known to play a role in MK or platelet function; these represent excellent candidates for future study of hematopoiesis, platelet formation, and/or platelet function.

Ticagrelor versus prasugrel in acute coronary syndrome: sex-specific analysis from the RENAMI Registry

BACKGROUND

The use of potent P2Y12 inhibitors (ticagrelor & prasugrel) in acute coronary syndrome (ACS) patients undergoing percutaneous coronary interventions (PCI) is a class I recommendation. We performed a sex-specific analysis comparing the difference in efficacy and safety outcomes between ticagrelor and prasugrel in a real-world ACS population.

METHODS

Data from the multicenter REgistry of New Antiplatelets in patients with Myocardial Infarction (RENAMI) for 4424 ACS patients who underwent PCI and were treated with ticagrelor or prasugrel between 2012 to 2016 were analyzed. Mean follow-up was 17±9 months.

RESULTS

After propensity score matching, there was no significant difference in the occurrence of primary endpoint of net adverse cardiac events between ticagrelor and prasugrel in men (HR: 0.94; 95% CI: 0.69-1.29; P=0.71), or women (HR: 1.17; 95% CI: 0.63-2.20; P=0.62; P interaction [sex] = 0.40). Similarly, no differences were found in the occurrence of any of the secondary endpoints (MACE, all cause death, re-infarction, stent thrombosis, BARC major bleeding and BARC any bleeding) between the two P2Y12 groups between men and women.

CONCLUSIONS

In this real-world ACS population, no relative difference in efficacy or safety outcomes were found between ticagrelor and prasugrel between sexes.

Use of Preventive Aspirin Among Older US Adults With and Without Diabetes

IMPORTANCE

The net benefit of aspirin for prevention of cardiovascular disease (CVD), particularly primary prevention, remains debated in people with and without diabetes. Recent studies suggest that the benefits of preventive aspirin may be outweighed by the potential for harm in older adults; therefore, it is important to monitor current aspirin use in order to minimize risk for future harm in the oldest segment of the population.

OBJECTIVE

To determine the prevalence of preventive aspirin use in older US adults with and without diabetes for both primary and secondary prevention by age, sex, and CVD risk category.

DESIGN, SETTING, AND PARTICIPANTS

This cross-sectional analysis used nationally representative data from the National Health and Nutrition Examination Survey from 2011 to 2018. A total of 7103 individuals 60 years or older with and without diabetes completed a questionnaire on preventive aspirin use. Statistical analyses were performed from July 1, 2019, to April 1, 2021.

MAIN OUTCOMES AND MEASURES

Preventive aspirin use was defined as participants' self-reported use of low-dose aspirin therapy based on their physician's advice or their own decision.

RESULTS

A total of 7103 individuals (mean [SD] age, 69.6 [0.1] years; 45.2% men; 75.8% White participants) were evaluated. Overall, 61.7% of older US adults with diabetes vs 42.2% without diabetes used aspirin. Among people with diabetes, in multivariable logistic models adjusting for race, sex, education, CVD risk category, and body mass index, the likelihood of aspirin use in older vs younger age categories (reference: 60-69 years) did not differ. Among people without diabetes, aspirin use was significantly greater in older age categories vs the reference (model 3, 70-79 years, odds ratio [OR], 1.50; 95% CI, 1.23-1.83; model 3, ≥80 years, OR, 1.59; 95% CI, 1.24-2.04). An estimated 9.9 million US adults 70 years or older with or without diabetes reported taking aspirin for primary prevention. The likelihood of aspirin use for primary prevention in those at high vs low risk for CVD did not differ among older adults with diabetes (model 3, OR, 1.69; 95% CI, 0.65-4.39) but was significantly higher in those without diabetes (model 3, OR, 2.46; 95% CI, 1.63-3.71). Women vs men with diabetes were less likely to be using aspirin for primary prevention (model 3, OR, 0.63; 95% CI, 0.48-0.83).

CONCLUSIONS AND RELEVANCE

This cross-sectional study found that preventive aspirin use was higher among older adults with diabetes than in those without diabetes. Results suggest that 9.9 million older US adults who previously took aspirin for primary prevention would not be recommended for its continued use, particularly among those with diabetes.

Sex and gender in cardiovascular medicine: presentation and outcomes of acute coronary syndrome

Although health disparities in women presenting with acute coronary syndrome (ACS) have received growing attention in recent years, clinical outcomes from ACS are still worse for women than for men. Women continue to experience higher patient and system delays and receive less aggressive invasive treatment and pharmacotherapies. Gender- and sex-specific variables that contribute to ACS vulnerability remain largely unknown. Notwithstanding the sex differences in baseline coronary anatomy and function, women and men are treated the same based on guidelines that were established from experimental and clinical trial data over-representing the male population. Importantly, younger women have a particularly unfavourable prognosis and a plethora of unanswered questions remains in this younger population. The present review summarizes contemporary evidence for gender and sex differences in vascular biology, clinical presentation, and outcomes of ACS. We further discuss potential mechanisms and non-traditional risk conditions modulating the course of disease in women and men, such as unrecognized psychosocial factors, sex-specific vascular and neural stress responses, and the potential impact of epigenetic modifications.

Sex- and Gender-Based Pharmacological Response to Drugs

In humans, the combination of all sex-specific genetic, epigenetic, and hormonal influences of biologic sex produces different in vivo environments for male and female cells. We dissect how these influences of sex modify the pharmacokinetics and pharmacodynamics of multiple drugs and provide examples for common drugs acting on specific organ systems. We also discuss how gender of physicians and patients may influence the therapeutic response to drugs. We aim to highlight sex as a genetic modifier of the pharmacological response to drugs, which should be considered as a necessary step toward precision medicine that will benefit men and women. SIGNIFICANCE STATEMENT: This study discusses the influences of biologic sex on the pharmacokinetics and pharmacodynamics of drugs and provides examples for common drugs acting on specific organ systems. This study also discusses how gender of physicians and patients influence the therapeutic response to drugs.

Gender Differences in Risk Factor Profile and Clinical Characteristics in 89 Consecutive Cases of Cerebral Venous Thrombosis

Gender has been shown to be an important variable in cerebral venous thrombosis (CVT) risk and significantly influences its clinical manifestations and outcome. The aim of our study was to investigate the gender-specific risk factor profile and clinical picture of this rare cerebrovascular disorder.

MATERIALS AND METHODS

We retrospectively reviewed the medical records of 89 consecutive cases of CVT at a tertiary neurology clinic in Târgu Mures, Romania, between June 2009 and January 2021 to analyze the gender-related differences in etiology, clinical presentation, and outcome.

RESULTS

Women comprised 62.5% of the cohort. Females were significantly younger than males (37.3 years versus 48.8 years, respectively, p = 0.001), and the main risk factors were hormone related in 37.9% of the cases, followed by primary thrombophilia (34.4%), smoking (25.8%), obesity (17.2%), infections (17.2%), mechanical factors (17.2%), cancer (8.6%), systemic autoimmune disorders (8.6%), and hematological disorders (8.6%). In male patients, the main risk factors were smoking (41.9%), primary thrombophilia (29%), infections (22.6%), heavy alcohol consumption (16.1%), and venous thromboembolism in the medical history (12.9%). Frequency of headache was higher in females than in males (75.9% versus 67.7%), whereas frequency of coma (6.5% in males versus 1.7% in females) and dizziness (19.4% in males versus 10.3% in females) was higher in males. CVT onset was acute in 41.4% of females and 38.7% of males. The Rankin score at discharge was significantly lower in females compared with males (0.6 versus 1.6), reflecting a more favorable short-term outcome. Mortality was 6.4% in males and 1.7% in females.

CONCLUSIONS

CVT is a multifactorial disorder that has a broad spectrum of risk factors with important gender-related differences in clinical manifestation and prognosis. Female patients, especially those with hormone-related risk factors, have a more favorable outcome than male patients.

The Influence of Lipid Excipients on Platelet Function and the Pharmacodynamic Effects of Aspirin

ABSTRACT

The combination of pharmaceutical lipid excipients with aspirin in a novel liquid oral formulation (Vazalore) limits gastrointestinal toxicity of aspirin. This study was performed to determine whether the lipid excipients influence the pharmacodynamic effects of aspirin and determine whether the excipients directly affect platelet function. The pharmacodynamic effects of aspirin were assessed over a range of concentrations designed to exert limited to maximal inhibition of cyclooxygenase-1 (COX1) necessary for thromboxane A2 production. Platelet aggregation induced by arachidonic acid and assessed with the use of light transmission aggregometry (LTA) was used as a direct measure of the inhibition of COX1 by aspirin. Flow cytometry was used to assess the direct effect of excipients on platelet function. Twice the ratio of lipid excipient to aspirin used in the formulation of the novel oral agent was used. Blood was taken from 20 healthy subjects and anticoagulated with trisodium citrate (3.2%, 1:10 v/v). Aspirin and excipients were added in vitro and incubated for 10 minutes before performance of LTA and flow cytometry. The excipients did not limit the pharmacodynamic effects of aspirin. When the extent of inhibition of platelet aggregation was limited, the excipients tended to enhance pharmacodynamic effects. The excipients did not activate platelets in the absence of agonist and did not alter activation of platelets in response to adenosine diphosphate, arachidonic acid, thrombin, or convulxin (a collagen mimetic). Lipid excipients used in an oral formulation of aspirin do not impair the pharmacodynamic effects of aspirin and do not alter platelet function.

Transcriptional profile of platelets and iPSC-derived megakaryocytes from whole-genome and RNA sequencing

Genome-wide association studies have identified common variants associated with platelet-related phenotypes, but because these variants are largely intronic or intergenic, their link to platelet biology is unclear. In 290 normal subjects from the GeneSTAR Research Study (110 African Americans [AAs] and 180 European Americans [EAs]), we generated whole-genome sequence data from whole blood and RNA sequence data from extracted nonribosomal RNA from 185 induced pluripotent stem cell-derived megakaryocyte (MK) cell lines (platelet precursor cells) and 290 blood platelet samples from these subjects. Using eigenMT software to select the peak single-nucleotide polymorphism (SNP) for each expressed gene, and meta-analyzing the results of AAs and EAs, we identify (q-value < 0.05) 946 cis-expression quantitative trait loci (eQTLs) in derived MKs and 1830 cis-eQTLs in blood platelets. Among the 57 eQTLs shared between the 2 tissues, the estimated directions of effect are very consistent (98.2% concordance). A high proportion of detected cis-eQTLs (74.9% in MKs and 84.3% in platelets) are unique to MKs and platelets compared with peak-associated SNP-expressed gene pairs of 48 other tissue types that are reported in version V7 of the Genotype-Tissue Expression Project. The locations of our identified eQTLs are significantly enriched for overlap with several annotation tracks highlighting genomic regions with specific functionality in MKs, including MK-specific DNAse hotspots, H3K27-acetylation marks, H3K4-methylation marks, enhancers, and superenhancers. These results offer insights into the regulatory signature of MKs and platelets, with significant overlap in genes expressed, eQTLs detected, and enrichment within known superenhancers relevant to platelet biology.

Impact of gender on immature platelet count and its relationship with coronary artery disease

The impact of platelet parameters on the cardiovascular risk is still debated. Gender differences in platelet volume indexes and turnover have been previously reported, potentially conditioning their role in the development of coronary artery disease (CAD). However, few studies have addressed, so far, the impact of gender on the immature platelet fraction (IPF) and count (IPC) and their relationship with CAD. We enrolled consecutive patients undergoing coronary angiography in a single centre. IPF and platelet indexes were measured at admission. Significant CAD was defined as the presence of at least one coronary stenosis more than 50%. A total of 2550 patients were included, 1835 (72%) were males, and 715 (28%) were females. Female patients were older (p < 0.001), with lower BMI (p = 0.002), lower prevalence of active smoking (p < 0.001), previous MI, previous PCI and CABG (p = 0.001, p = 0.001, p < 0.001), whilst a higher prevalence of renal failure (p = 0.02), acute presentation (p < 0.001) and CAD (p < 0.001). Platelet count was higher in females (p < 0.001), as well as the IPC levels (838.38 ± 562.05 vs 792.24 ± 535.66, p = 0.05) with no difference in the levels of immature platelet fraction (3.67 ± 2.68% vs 3.74 ± 2.6%, p = 0.55) or the prevalence of patients with IPF ≥ 3rd tertile (33.7% vs 35.2%, p = 0.26). At multivariate analysis, after correction for baseline confounders, gender did not emerge as an independent predictor of higher IPF (adjusted OR [95% CI] = 0.82 [0.64-1.06], p = 0.13). When dividing our patients according to the levels of IPF, in women we observed an inverse association between IPF ≥ 3rd tertile and coronary calcifications (p = 0.025) and a higher prevalence of restenosis (p = 0.003), but no difference in CAD (65.6% vs 66.9%, p = 0.71) or severe CAD (28.1% vs 24.7%, p = 0.31). In males, the IPF ≥ 3rd tertile related with a lower TIMI flow (p = 0.001). Males with lower IPF had a significantly higher percentage of CAD (87.7% vs 83.3%, p = 0.007; adjusted OR: 0.699 [95% CI] = [0.54-0.91], p = 0.008) but not for severe CAD (36.5% vs 39.9%, p = 0.134). The present study shows that among patients undergoing coronary angiography, gender is not associated to the levels of immature platelet fraction. Moreover, we found no association between IPF and the prevalence and extent of CAD in female gender, whereas in male gender the IPF was inversely related with the prevalence of CAD.

GenoPheno: cataloging large-scale phenotypic and next-generation sequencing data within human datasets

Precision medicine promises to revolutionize treatment, shifting therapeutic approaches from the classical one-size-fits-all to those more tailored to the patient's individual genomic profile, lifestyle and environmental exposures. Yet, to advance precision medicine's main objective-ensuring the optimum diagnosis, treatment and prognosis for each individual-investigators need access to large-scale clinical and genomic data repositories. Despite the vast proliferation of these datasets, locating and obtaining access to many remains a challenge. We sought to provide an overview of available patient-level datasets that contain both genotypic data, obtained by next-generation sequencing, and phenotypic data-and to create a dynamic, online catalog for consultation, contribution and revision by the research community. Datasets included in this review conform to six specific inclusion parameters that are: (i) contain data from more than 500 human subjects; (ii) contain both genotypic and phenotypic data from the same subjects; (iii) include whole genome sequencing or whole exome sequencing data; (iv) include at least 100 recorded phenotypic variables per subject; (v) accessible through a website or collaboration with investigators and (vi) make access information available in English. Using these criteria, we identified 30 datasets, reviewed them and provided results in the release version of a catalog, which is publicly available through a dynamic Web application and on GitHub. Users can review as well as contribute new datasets for inclusion (Web: https://avillachlab.shinyapps.io/genophenocatalog/; GitHub: https://github.com/hms-dbmi/GenoPheno-CatalogShiny).

Sex-Specific Platelet Activation Through Protease-Activated Receptors Reverses in Myocardial Infarction

OBJECTIVE

The platelet phenotype in certain patients and clinical contexts may differ from healthy conditions. We evaluated platelet activation through specific receptors in healthy men and women, comparing this to patients presenting with ST-segment-elevation myocardial infarction and non-ST-segment-elevation myocardial infarction. Approach and Results: We identified independent predictors of platelet activation through certain receptors and a murine MI model further explored these findings. Platelets from healthy women and female mice are more reactive through PARs (protease-activated receptors) compared with platelets from men and male mice. Multivariate regression analyses revealed male sex and non-ST-segment-elevation myocardial infarction as independent predictors of enhanced PAR1 activation in human platelets. Platelet PAR1 signaling decreased in women and increased in men during MI which was the opposite of what was observed during healthy conditions. Similarly, in mice, thrombin-mediated platelet activation was greater in healthy females compared with males, and lesser in females compared with males at the time of MI.

CONCLUSIONS

Sex-specific signaling in platelets seems to be a cross-species phenomenon. The divergent platelet phenotype in males and females at the time of MI suggests a sex-specific antiplatelet drug regimen should be prospectively evaluated.

Impact of High-Density Lipoprotein Levels on Cardiovascular Outcomes of Patients Undergoing Percutaneous Coronary Intervention With Drug-Eluting Stents

Low levels of high-density lipoprotein (HDL) have been associated with adverse cardiovascular events in epidemiologic studies. Evidence regarding its role in patients who underwent percutaneous coronary intervention (PCI) is scarce. We evaluated consecutive patients who underwent PCI with drug-eluting stents from 2012 to 2017, excluding those with unavailable baseline HDL, age <18 years, presentation with ST-segment elevation myocardial infarction (MI) or shock, and coexisting neoplastic disease. The final population was stratified according to baseline HDL levels into reduced and nonreduced HDL cohorts, with cut-off value 40 mg/dl in males and 50 mg/dl in females. The primary end point was 1-year major adverse cardiovascular events (MACE), defined as the composite of death, MI, or target vessel revascularization (TVR). Among 10,843 patients included, 6,511 (60%) had reduced HDL, and 4,332 (40%) nonreduced HDL. The rate of 1-year MACE was similar between the 2 groups (7.5% vs 6.6%; p = 0.14). Although mortality and MI rates were comparable, reduced HDL was associated with significantly higher TVR 5.2% vs 4.0%; p = 0.02, a finding that attenuated after multivariable adjustment (adjusted hazard ratio 1.18, p = 0.14). Sex subgroup analysis included 7,718 (71.2%) males and 3,125 (28.8%) females. Among men, there was a trend toward higher MACE in those with reduced HDL (7.4% vs 6.0%; p = 0.08) mostly driven by TVR (5.4% vs 3.7%; p = 0.005). No association between HDL and 1-year outcomes was evident in females. Assessment for interaction between sex and reduced HDL did not reach statistical significance. In conclusion, reduced baseline HDL was not associated with increased risk of MACE in a contemporary PCI population.

Influence of Sex on Platelet Reactivity in Response to Aspirin

Background There are sex differences in the efficacy and safety of aspirin for the prevention of myocardial infarction and stroke. Whether this is explained by underlying differences in platelet reactivity and aspirin response remains poorly understood. Methods and Results Healthy volunteers (n=378 208 women) and patients with coronary artery disease or coronary artery disease risk factors (n=217 112 women) took aspirin for 4 weeks. Light transmittance aggregometry using platelet-rich plasma was used to measure platelet reactivity in response to epinephrine, collagen, and ADP at baseline, 3 hours after the first aspirin dose, and after 4 weeks of daily aspirin therapy. A subset of patients underwent pharmacokinetic and pharmacodynamic assessment with levels of salicylate and cyclooxygenase-1-derived prostaglandin metabolites and light transmittance aggregometry in response to arachidonic acid and after ex vivo exposure to aspirin. At baseline, women had increased platelet aggregation in response to ADP and collagen. Innate platelet response to aspirin, assessed with ex vivo aspirin exposure of baseline platelets, did not differ by sex. Three hours after the first oral aspirin dose, platelet aggregation was inhibited in women to a greater degree in response to epinephrine and to a lesser degree with collagen. After 4 weeks of daily therapy, despite higher salicylate concentrations and greater cyclooxygenase-1 inhibition, women exhibited an attenuation of platelet inhibition in response to epinephrine and ADP. Conclusions We observed agonist-dependent sex differences in platelet responses to aspirin. Despite higher cyclooxygenase-1 inhibition, daily aspirin exposure resulted in a paradoxical attenuation of platelet inhibition in response to epinephrine and ADP over time in women but not in men.

Genetic Variation in PEAR1, Cardiovascular Outcomes and Effects of Aspirin in a Healthy Elderly Population

The platelet endothelial aggregation receptor-1 (PEAR1) rs12041331 variant has been identified as a genetic determinant of platelet aggregation in response to antiplatelet therapies, including aspirin. However, association with atherothrombotic cardiovascular events is less clear, with limited evidence from large trials. Here, we tested association of rs12041331 with cardiovascular events and aspirin use in a randomized trial population of healthy older individuals. We undertook post hoc analysis of 13,547 participants of the ASPirin in Reducing Events in the Elderly (ASPREE) trial, median age 74 years. Participants had no previous diagnosis of atherothrombotic cardiovascular disease at enrollment, and were randomized to either 100 mg daily low-dose aspirin or placebo for median 4.7 years follow-up. We used Cox proportional hazard regression to model the relationship between rs12041331 and the ASPREE primary cardiovascular disease (CVD) end point, and composites of major adverse cardiovascular events (MACE) and ischemic stroke (STROKE); and bleeding events; major hemorrhage (MHEM) and intracranial bleeding (ICB). We performed whole-population analysis using additive and dominant inheritance models, then stratified by treatment group. Interaction effects between genotypes and treatment group were examined. We observed no statistically significant association (P < 0.05) in the population, or by treatment group, between rs12041331 and cardiovascular or bleeding events in either model. We also found no significant interaction effects between rs12041331-A and treatment group, for CVD (P = 0.65), MACE (P = 0.32), STROKE (P = 0.56), MHEM (P = 0.59), or ICB (P = 0.56). The genetic variant PEAR1 rs12041331 is not associated with cardiovascular events in response to low-dose aspirin in a healthy elderly population.

Platelet Measurements and Type 2 Diabetes: Investigations in Two Population-Based Cohorts

Type 2 diabetes is a major risk factor for cardiovascular disease. Given the contribution of platelets to atherothrombosis—which in turn is a major contributor to cardiac events, there may be cause to consider platelet function in management of diabetes. Despite the large body of research concerning the role of platelets in cardiovascular complications of type 2 diabetes, evidence from population-based studies of platelet aggregation in diabetes is limited. Mean Platelet Volume (MPV), a cell trait partially associated with markers of platelet activity, is more commonly available. We investigated the association of metabolic syndrome and diabetes with platelet aggregation to three physiological agonists, ADP, collagen, and epinephrine, in the Framingham Heart Study Offspring cohort. We further examined the relationship between MPV measured with Beckman Coulter LH750 instruments and self-reported diabetes as well as MPV and diabetes medication in the UK BioBank cohort, performing the largest such analysis to date. Increased platelet aggregation associated with prevalent diabetes was observed for low concentration epinephrine (0.1 μM) alone and only in analyses of participants stratified either by male sex and/or having metabolic syndrome. Other agonists and concentrations were not significant for prevalent diabetes, or in opposite direction to the main hypothesis (i.e., they showed lower platelet aggregation associated with diabetes). After a median of 18.1 years follow-up, no platelet aggregation trait was associated with increased risk of diabetes (n = 344 cases). As expected, increased MPV was significantly associated with diabetes (β = 0.0976; P = 8.62 × 10⁻³³). Interestingly, sex-stratified analyses indicated the association of MPV with diabetes is markedly stronger in males (β = 0.1232; P = 1.00 × 10⁻³¹) than females (β = 0.0514; P = 7.37 × 10⁻⁵). Among diabetes medications increased MPV was associated with Insulin (β = 0.1341; P = 1.38 × 10⁻¹¹) and decreased MPV with both Metformin (β = 0.0763; P = 1.99 × 10⁻⁶) as well as the sulphonylureas (β = 0.0559; P = 0.0034). Each drug showed the same direction of effect in both sexes, however, the association with MPV was nearly twice as great or more in women compared to men. In conclusion, platelet function as measured by aggregation to ADP, collagen, or epinephrine does not appear to be consistently associated with diabetes, however, MPV is robustly associated suggesting future work may focus on how MPV segments pre-diabetics and diabetics for risk prediction.

Sex differences in flow cytometry-based platelet reactivity in stable outpatients suspected of myocardial ischemia

BACKGROUND

Antiplatelet therapy is the mainstay of secondary prevention of cardiovascular events. Studies suggest that women do not obtain equal therapeutic benefit from antiplatelet therapy compared with men. The link between sex differences in platelet biology and response to antiplatelet therapies is unclear. We therefore investigated the role of sex differences in platelet reactivity in a cohort of outpatients with chest pain, in response to treatment with antiplatelet agents.

METHODS

Platelet reactivity was measured in 382 randomly selected patients participating in the Myocardial Ischemia Detection by Circulating Biomarkers (MYOMARKER) study, an observational cohort study of outpatients suspected of myocardial ischemia. In all patients, blood was collected during diagnostic workup, and platelet reactivity was assessed with a flow cytometry-based platelet activation test that quantifies both platelet degranulation (P-selectin expression) and platelet aggregation (fibrinogen binding to integrin αIIbβ3) in whole blood.

RESULTS

Platelet reactivity was higher in women compared with men when activated with protease activating receptor 1-activating peptide SFLLRN (PAR1-AP) and adenosine 5'-phosphate (ADP), independent of age, basal activation status, estimated glomerular filtration rate < 60, platelet count, statin use, the use of P2Y12 inhibitors, or the use of aspirin. P2Y12 inhibitor use strongly reduced fibrinogen binding after stimulation with PAR1-AP, but only slightly reduced platelet P-selectin expression. Calculation of the relative inhibition in P2Y12 users indicated 62% inhibition of the response toward ADP. Stratified analysis showed that women (n = 14) using P2Y12 inhibitors showed less inhibition of fibrinogen binding after PAR1-AP stimulation than men (n = 38) using P2Y12 inhibitors.

CONCLUSIONS

These findings call for further study of differential effects of P2Y12 inhibitors in women with suspected myocardial ischemia.

Is There Still a Role for Aspirin in Primary Prevention in Women in 2020?

PURPOSE OF REVIEW

Aspirin's place in primary prevention for females has not been well delineated and has been under increased scrutiny in light of recent literature and guideline recommendations. The purpose of this review is to discuss current literature reviewing aspirin use for primary prevention in women and to discuss when use is appropriate.

RECENT FINDINGS

The Women's Health Study found no differences in major adverse cardiovascular events (MACE) in women randomized to aspirin vs. placebo, though a significant reduction was observed in women ≥ 65 years. More recent literature evaluated outcomes for primary prevention use in patients at increased cardiovascular risk, patients with diabetes, and patients who are elderly. These trials found either no benefit in MACE outcomes or a slight benefit accompanied by an increased risk of bleeding. Furthermore, no difference in outcomes were found in subgroup analyses comparing females receiving aspirin vs. placebo or comparing events in males vs. females. With improvements in risk factor reduction, such as blood pressure control, statin use, diabetes management, and smoking cessation, the role of aspirin for primary prevention in women is still uncertain. Aspirin use for primary prevention in females has failed to show a clear benefit except in women ≥ 65 years old, with a potential increase in bleeding events. An effort to better study aspirin in female patients would allow for better identification of women who would or would not benefit from therapy.