Serotonin‐affecting antidepressant use in relation to platelet reactivity

Does Concomitant Use of Antidepressants and Direct Oral Anticoagulants Increase the Risk of Bleeding?: A Systematic Review and Meta-Analysis

PURPOSE

To evaluate the risk of bleeding associated with the simultaneous administration of antidepressants (ADs) and direct oral anticoagulants (DOACs).

METHODS

PubMed, Embase, and Scopus databases were searched for papers that focused on the concomitant administration of ADs and DOACs and presented data on the bleeding outcomes. The comparator group of interest was subjects who received only DOACs. Besides the overall pooled analysis, irrespective of the primary disease condition, we were also interested in studies involving patients with atrial fibrillation (AF). We therefore included studies with relevant comparisons (AD with DOACs, compared to DOACs alone), regardless of the reported underlying condition. Thereafter, we conducted a sensitivity analysis to refine estimates specific to AF. Clinical trials and observational studies were eligible. Pooled effect sizes were reported as relative risk (RR) for studies with cohort design and as odds ratio (OR) for case-control studies.

RESULTS

Ten studies were included. Overall pooled analysis showed that treatment with both DOAC and selective serotonin reuptake inhibitor and serotonin and norepinephrine reuptake inhibitor (SSRI/SNRI) was associated with significantly higher risk of major bleeding (cohort: RR 1.25, 95% CI: 1.07-1.47; case-control: OR 1.40, 95% CI: 1.15-1.69). The risk of intracranial bleeding was found to be increased when cohort studies were pooled (RR 1.44, 95% CI: 1.24-1.66), but not with pooling of case-control studies (OR 1.58, 95% CI: 0.43-5.75). The risk of gastrointestinal bleeding and transient ischemic attack (TIA)/ischemic stroke was comparable between the 2 groups (DOAC + SSRI/SNRI vs DOAC only group).

CONCLUSIONS

Our results indicate that combined SSRIs/SNRIs and DOAC treatment may be associated with increased incidence of major and intracranial bleeding, further emphasizing the importance of caution when considering their concomitant use.

Hyperactivity in the Hypothalamic-Pituitary-Adrenal Axis: An Invisible Killer for Anxiety and/or Depression in Coronary Artherosclerotic Heart Disease

The coexistence of anxiety or depression with coronary heart disease (CHD) is a significant clinical challenge in cardiovascular medicine. Recent studies have indicated that hypothalamic-pituitary-adrenal (HPA) axis activity could be a promising focus in understanding and addressing the development of treatments for comorbid CHD and anxiety or depression. The HPA axis helps to regulate the levels of inflammatory factors, thereby reducing oxidative stress damage, promoting platelet activation, and stabilizing gut microbiota, which enhance the survival and regeneration of neurons, endothelial cells, and other cell types, leading to neuroprotective and cardioprotective benefits. This review addresses the relevance of the HPA axis to the cardiovascular and nervous systems, as well as the latest research advancements regarding its mechanisms of action. The discussion includes a detailed function of the HPA axis in regulating the processes mentioned. Above all, it summarizes the therapeutic potential of HPA axis function as a biomarker for coronary atherosclerotic heart disease combined with anxiety or depression.

Sertraline in depressed patients with or at risk for coronary heart disese: a systemic review

BACKGROUND AND AIMS

Depression is a prevalent comorbidity among patients with coronary heart disease (CHD). While recent studies have hinted at a possible association between CHD and antidepressant medications like sertraline, the existing evidence remains inconclusive. To investigate this potential link, we conducted a comprehensive systematic review.

METHODS

We systematically searched PubMed, Google Scholar, and Scopus for relevant articles published up to March 2023. After a thorough screening of titles and abstracts, 12 studies were included in our review.

RESULTS

The included studies, spanning from 1999 to 2021, comprised 11 randomized controlled trials (RCTs) and one pilot study. A total of 2767 participants with major depressive disorder and a history of cardiovascular disease or at risk for such events were included. The majority of these studies demonstrated improvements in mood status among patients treated with serotonin-targeting antidepressants and a reduced risk of cardiovascular events, as measured by various outcomes. While some cardiac adverse effects were observed with serotonin treatment, these did not reach statistical significance.

CONCLUSION

Our findings provide evidence supporting the beneficial effects of serotonin-targeting antidepressants for both depressive symptoms and the prevention of coronary adverse outcomes. These results highlight the potential value of serotonin-based treatments for depression in high-risk populations.

Neuro-inflammatory pathways in COVID-19-induced central nervous system injury: Implications for prevention and treatment strategies

This review explores the neuroinflammatory pathways underlying COVID-19-induced central nervous system (CNS) injury, with a focus on mechanisms of brain damage and strategies for prevention. A comprehensive literature review was conducted to summarize current knowledge on the pathways by which SARS-CoV-2 reaches the brain, the neuroinflammatory responses triggered by viral infection, neurological symptoms and long COVID. Results: We discuss the mechanisms of neuroinflammation in COVID-19, including blood-brain barrier disruption, cytokine storm, microglial activation, and peripheral immune cell infiltration. Additionally, we highlight potential strategies for preventing CNS injury, including pharmacological interventions, immunomodulatory therapies, and lifestyle modifications. Conclusively, Understanding the neuroinflammatory pathways in COVID-19-induced CNS injury is crucial for developing effective prevention and treatment strategies to protect brain health during and after viral infection.

Cardiorespiratory Fitness Is Associated with Decreased Platelet Reactivity

PURPOSE

Platelets are key mediators in cardiovascular disease (CVD). Low cardiorespiratory fitness (CRF) is a risk factor for CVD. The purpose of our study was to assess if CRF associates with platelet function.

METHODS

Platelet assays and cardiopulmonary exercise testing were conducted in the Framingham Heart Study ( N = 3014). Linear mixed effects models estimated associations between CRF (assessed by peak oxygen uptake [V̇O 2 ]) and multiple platelet reactivity assays. Models were adjusted for multiple medications, risk factors, relatedness, and prevalent CVD.

RESULTS

Nineteen associations passed the significance threshold in the fully adjusted models, all indicating higher CRF associated with decreased platelet reactivity. Significant traits spanned multiple platelet agonists. Strongest associations were observed in multiplate whole blood testing after TRAP-6 (e.g., velocity, beta = -0.563, 95% CI = -0.735 to -0.391, P = 1.38E-10), ADP (e.g., velocity, beta = -0.514, 95% CI = -0.681 to -0348, P = 1.41E-09), collagen (e.g., velocity, beta = -0.387, 95% CI = -0.549 to -0.224, P = 3.01E-06), ristocetin (e.g., AUC, beta = -0.365, 95% CI = -0.522 to -0.208, P = 5.17E-06) and arachidonic acid stimulation of platelets (e.g., velocity, beta = -0.298, 95% CI = -0.435 to -0.162, P = 3.39E-04), and light transmission aggregometry (LTA) after ristocetin stimulation (e.g., max aggregation, beta = -0.362, 95% CI = -0.540 to -0.184, P = 6.64E-05). One trait passed significance threshold in the aspirin subsample (LTA ristocetin primary slope, beta = -0.733, 95% CI = -1.134 to -0.333, P = 3.30E-04) and another in a model including von Willebrand Factor levels as a covariate (U46619, a thromboxane receptor mimetic, AUC in the Optimul assay, beta = -0.36, 95% CI = -0.551 to -0.168, P = 2.35E-04). No strong interactions were observed between the associations and sex, age, or body mass index in formal interaction analyses.

CONCLUSIONS

Our findings build on past work that shows CRF to be associated with reduced CVD by suggesting decreased platelet reactivity may play a mechanistic role. We found significant associations with multiple platelet agonists, indicating higher CRF may globally inhibit platelets; however, given multiple strong associations after TRAP-6 and ADP stimulation, PAR-1 and purinergic signaling may be most heavily involved. This is notable because each of these receptor pathways are tied to anticoagulant (DOAC/thrombin inhibitors) and antiplatelet therapies (P2Y12/PAR1/PAR4 inhibitors) for CVD prevention.

Nonvitamin K Anticoagulants: Risk of Bleeding When Interacting With Other Medications: A Cohort Study From Medicare

INTRODUCTION

Patients on nonvitamin K antagonist (NVKA) are usually taking other drugs. Potential interaction may increase the gastrointestinal (GI) bleeding risk associated with NVKA.

METHODS

Observational cohort study using Medicare data from 2017 to 2020. Participants receiving a NVKA were included. A concomitant overlapping period while on NVKA was assessed for nonsteroidal anti-inflammatory drugs (NSAIDS), selective serotonin reuptake inhibitors (SSRI), antiplatelets, glucocorticoids, aspirin and proton pump inhibitors (PPI). A logistic regression predicting either any bleeding or GI bleeding was conducted estimating the odds ratio (OR) and 95% confidence interval (CI).

RESULTS

A total of 102 531 people on NVKA with mean age 77 years (SD = 9.8) and 55% females (N = 56 671) were included. Previous history of GI bleeding occurred in 2 908 (2.8%) participants, concomitant exposure to PPI occurred in 38 713 (38%), SSRI in 16 487 (16%), clopidogrel in 15 795 (15.4%), NSAIDs in 13 715 (13.4%) and glucocorticoids in 13 715 (13.4%). Risk for any bleeding was shown for clopidogrel (OR: 1.37, 95% CI: 1.30, 1.44), prasugrel/ticagrelor (OR: 1.36, 95% CI: 1.18, 1.58), glucocorticoids (OR: 1.26, 95% CI: 1.19, 1.34), and SSRIs (OR: 1.13, 95% CI: 1.07, 1.19). GI bleeding risk was shown for clopidogrel (OR: 1.44, 95% CI: 1.34, 1.55), prasugrel/ticagrelor (OR: 1.47, 95% CI: 1.20, 1.79), SSRIs (OR: 1.09, 95% CI: 1.01, 1.17) and glucocorticoids (OR: 1.33, 95% CI: 1.23, 1.44). PPI use was correlated with both NSAID (r = 0.07, p ≤ 0.0001) and SSRI use (r = 0.09, p ≤ 0.0001).

CONCLUSION

NVKA concomitantly taken with antiplatelets, glucocorticoids, and SSRIs showed an increased risk for any bleeding and GI bleeding.

A Biobehavioral Perspective on Caring for Allogeneic Hematopoietic Stem Cell Transplant Survivors with Graft-Versus-Host Disease

Among the potential complications of allogeneic hematopoietic stem cell transplantation (HSCT), graft-versus-host disease (GVHD) is common and associated with significant physical and psychosocial symptom burden. Despite substantial advances in GVHD treatment, the global immune suppression that frequently accompanies GVHD treatment also contributes to high rates of physical and emotional suffering and mortality. The complex manifestations of GVHD and its treatment warrant a multidisciplinary team-based approach to managing patients' multi-organ system comorbidities. A biobehavioral framework can enhance our understanding of the complex association between medications, physical symptoms, and psychosocial distress in patients with GVHD. Hence, for this perspective, we highlight the importance of addressing both the physical and psychosocial needs experienced by patients with GVHD and provide guidance on how to approach and manage those symptoms and concerns as part of comprehensive cancer care.

Obstructive Sleep Apnea, Platelet Aggregation, and Cardiovascular Risk

BACKGROUND

Although related, the precise mechanisms linking obstructive sleep apnea (OSA) and cardiovascular disease (CVD) are unclear. Platelets are mediators of CVD risk and thrombosis and prior studies suggested associations of OSA and platelet activity. The aim of this study is to assess the link between OSA, platelet activity, and CVD-related risk factors.

METHODS AND RESULTS

We studied the association of OSA-measures and platelet aggregation in participants dually enrolled in the SHHS (Sleep Heart and Health Study) and FHS (Framingham Heart Study). We applied linear regression models with adjustment for demographic and clinical covariates and explored interactions with OSA and CVD-related factors, including age, sex, body mass index, hypertension, OSA diagnosis (apnea-hypopnea index 4%≥5), and aspirin use. Our final sample was of 482 participants (60 years [14.00], 50.4% female). No associations were observed between apnea-hypopnea index 4% and platelet aggregation in the main sample. Stratified analysis revealed an association in aspirin users (n=65) for our primary exposure (apnea-hypopnea index 4%, β=0.523; P<0.001; n=65), and secondary exposures: hypoxic burden (β=0.358; P<0.001), minimum saturation (β=-0.519; P=0.026), and oxygen desaturation index 3% (β=74.672; P=0.002). No associations were detected in nonaspirin users (n=417).

CONCLUSIONS

No associations were detected between OSA and platelet aggregation in a community sample. Our finding that OSA associates with increased platelet aggregation in the aspirin group, most of whom use it for primary prevention of CVD, suggests that platelet aggregation may mediate the adverse impact of OSA on vascular health in individuals with existing CVD risk, supporting further investigation.

The association between levels of brain-derived neurotrophic factor and comorbid depression in patients with cardiovascular disease: The Framingham Heart Study

AIM

The current study aims to investigate the association of serum brain-derived neurotrophic factor (BDNF) levels with symptoms of depression in adults with and without prevalent cardiovascular disease (CVD), an often burdensome comorbidity.

METHODS

This cross-sectional study included participants from FHS (Framingham Heart Study) who had available serum BDNF levels. Depressive symptoms were assessed using the Center for Epidemiological Studies-Depression Scale (CES-D) with a score ≥16 indicating mild to moderate and ≥21 severe depression. Participants taking antidepressant medications were excluded from the study.

RESULTS

Altogether 3716 FHS participants were included in the final analysis (mean age, 64.3 ± 11.5 years; 55% women). After adjusting for potential confounders, greater BDNF levels were associated with reduced severe depression risk (odds ratio [OR], 0.78 [95% CI, 0.64-0.96]; P = 0.016). Among participants with CVD, greater BDNF levels were related to lower risk of depressive symptoms (CES-D ≥ 16 OR, 0.63 [95% CI, 0.45-0.89], P = 0.008; CES-D ≥ 21 OR, 0.49 [95% CI, 0.31-0.76], P = 0.002). The inverse relationship between BDNF and depressive symptom risk was present in women with CVD (CES-D ≥ 16 OR, 0.63 [95% CI, 0.40-0.99], P = 0.047; CES-D ≥ 21 OR, 0.38 [95% CI, 0.21-0.70], P = 0.002) but not in men.

CONCLUSION

Lower serum BDNF levels are associated with a higher risk of depressive symptoms in CVD, particularly among women. These findings implicate BDNF in the complex biological mechanisms that underlie prior associations observed between CVD and depression. To reduce the burden of depression in the large proportion of midlife and older adults with CVD, a better understanding of how BDNF may modify these pathways is merited.

The study of platelet aggregation using a microtiter plate reader ‒ methodological considerations

Optical aggregometry by 96-well plate assay, the microplate method, is a fast, efficient, and readily available method for measuring the pharmacological effects of antiplatelet drugs. Even though recent years have witnessed growing interest in adopting the microplate method for widespread use, it remains in the shadow of the standard light transmission aggregometry (LTA). Regardless of the method used, the results of platelet aggregation depend on a variety of factors and often vary among laboratories worldwide. While several methodological papers have examined the microplate method, no standards have been established, most likely because the approach is not used as a diagnostic tool. Currently, the microplate method is recommended by researchers to be used in conjunction with LTA or as an adjunct to LTA. This raises the question of whether an optimal protocol exists for microplate aggregometry, and what are the key considerations in a good experimental protocol for obtaining reliable results? This article attempts to address these questions by summarizing the knowledge accumulated in this field over the last three decades.

Bleeding in patients on concurrent treatment with a selective serotonin reuptake inhibitor (SSRI) and low-dose acetylsalicylic acid (ASA) compared with SSRI or low-dose ASA alone-A systematic review and meta-analysis

AIMS

The aim of this study was to systematically review whether concurrent treatment with an SSRI and low-dose ASA increases the risk of bleeding compared with treatment with an SSRI alone or ASA alone.

METHODS

Medline, Embase, the Cochrane Library, PsycINFO and Web of Science (from database inception to January 2023) were searched according to PICO: P = patients on treatment with an SSRI and/or low-dose ASA; I = intervention: SSRI + ASA; C = comparison: ASA or SSRI alone; O = outcomes: bleeding/major bleeding. The included articles were assessed using checklists. Studies without major risk of bias formed the basis for the conclusions. Extracted data were pooled using random-effects meta-analyses. Certainty of evidence was assessed according to GRADE.

RESULTS

Twenty-four studies met the PICO and were included. One randomized and six nonrandomized studies were assessed not to have major risk of bias. Regarding SSRI + ASA vs. ASA only, the pooled hazard ratio of three nonrandomized studies (n = 38 467) was 1.37 (95% confidence interval: 1.10; 1.70; I2 = 0%), and the pooled odds ratio of two nonrandomized studies (n = 28 296) was 0.95 (0.77; 1.19; I2 = 0%). Regarding SSRI + ASA vs. SSRI only, the randomized controlled trial (n = 1048) reported a hazard ratio of 1.82 (0.66; 5.02), the hazard ratio being 1.60 (1.24; 2.06) for ASA vs. placebo in patients without SSRI treatment; and one nonrandomized controlled study (n = 18 920) reported an incidence rate ratio of 1.03 (0.96; 1.12).

CONCLUSIONS

The compiled evidence was too uncertain to support an interaction when an SSRI is added to low-dose ASA. Low-dose ASA added to an SSRI may imply an increased risk of bleeding primarily attributable to the initiation of ASA.

Heterogeneity of platelets and their responses

There has been increasing recognition of heterogeneity in blood platelets and their responses, particularly in recent years, where next-generation technologies and advanced bioinformatic tools that interrogate "big data" have enabled large-scale studies of RNA and protein expression across a growing list of disease states. However, pioneering platelet biologists and clinicians were already hypothesizing upon and investigating heterogeneity in platelet (and megakaryocyte) activity and platelet metabolism and aggregation over half a century ago. Building on their foundational hypotheses, in particular Professor Marian A. Packham's pioneering work and a State of the Art lecture in her memoriam at the 2023 International Society on Thrombosis and Haemostasis Congress by Anandi Krishnan, this review outlines the key features that contribute to the heterogeneity of platelets between and within individuals. Starting with important epidemiologic factors, we move stepwise through successively smaller scales down to heterogeneity revealed by single-cell technologies in health and disease. We hope that this overview will urge future scientific and clinical studies to recognize and account for heterogeneity of platelets and aim to apply methods that capture that heterogeneity. Finally, we summarize other exciting new data presented on this topic at the 2023 International Society on Thrombosis and Haemostasis Congress.

Alcohol intake including wine drinking is associated with decreased platelet reactivity in a large population sample

BACKGROUND

Alcohol consumption is linked to decreased platelet function. Whether this link is dependent on sex or type of beverage remains unclear.

METHODS

Cross-sectional data were obtained from the Framingham Heart Study (N = 3427). Alcohol consumption was assessed by using standardized medical history and Harvard semi-quantitative food frequency questionnaires. Five bioassays measured 120 platelet reactivity traits across agonists in whole-blood and platelet-rich plasma samples. Linear mixed-effects models adjusted for age, sex and aspirin use, hypertension, body mass index, cholesterol, high-density lipoprotein, triglycerides, smoking and diabetes evaluated associations between platelet reactivity and alcohol consumption. Beta effects, the regression coefficients that estimate the amount of change in each unit of the predictor variable whereas all other predictor variables remain fixed, for heavy alcohol consumption were compared with effects of aspirin use.

RESULTS

Alcohol consumption was associated with decreased platelet reactivity, with more associations among wine and liquor compared with beer. Many platelet-alcohol associations in the full sample (86%, P < 0.01) had larger effect sizes in females. Lower light transmission aggregometry adenosine diphosphate (1.82 µM) maximum aggregation (P = 2.6E-3, 95% CI = -0.07, -0.02, β = -0.042) and area under the curve (P = 7.7E-3, 95% CI = -0.07, -0.01, β = -0.039) were associated with white wine consumption; however, red wine had no associations with platelet reactivity. The effect of aspirin use was on average 11.3 (±4.0) times greater than that of heavy drinking in our full sample.

CONCLUSIONS

We confirm associations between alcohol consumption and decreased platelet reactivity. Effects appeared larger for liquor and wine intake and in our female cohort. Red wine consumption is not associated with lower platelet function, contrasting with prior population studies. Although we report an inhibitory relationship between alcohol intake and platelet function, these effects appear much smaller than that of aspirin use.

Trends among platelet function, arterial calcium, and vascular function measures

Arterial tonometry and vascular calcification measures are useful in cardiovascular disease (CVD) risk assessment. Prior studies found associations between tonometry measures, arterial calcium, and CVD risk. Activated platelets release angiopoietin-1 and other factors, which may connect vascular structure and platelet function. We analyzed arterial tonometry, platelet function, aortic, thoracic and coronary calcium, and thoracic and abdominal aorta diameters measured in the Framingham Heart Study Gen3/NOS/OMNI-2 cohorts (n = 3,429, 53.7% women, mean age 54.4 years ±9.3). Platelet reactivity in whole blood or platelet-rich plasma was assessed using 5 assays and 7 agonists. We analyzed linear mixed effects models with platelet reactivity phenotypes as outcomes, adjusting for CVD risk factors and family structure. Higher arterial calcium trended with higher platelet reactivity, whereas larger aortic diameters trended with lower platelet reactivity. Characteristic impedance (Zc) and central pulse pressure positively trended with various platelet traits, while pulse wave velocity and Zc negatively trended with collagen, ADP, and epinephrine traits. All results did not pass a stringent multiple test correction threshold (p < 2.22e-04). The diameter trends were consistent with lower shear environments invoking less platelet reactivity. The vessel calcium trends were consistent with subclinical atherosclerosis and platelet activation being inter-related.

Selective serotonin reuptake inhibitor use, age-related neuropathology and cognition in late-life

The objective of this study was to evaluate an association of selective serotonin reuptake inhibitor (SSRI) use with late life cognitive decline and further investigate the association with brain pathology. Using the data are from two harmonized clinical-pathologic cohort studies with annual cognitive testing we found that SSRI use was associated with significantly faster global cognitive decline and this association was present in those with and without pre-existing cognitive impairment at the time of SSRI initiation. In separate analyses of persons who died during the study and underwent neuropathologic examination, SSRI use was related to higher level of paired helical filament tau tangles and faster rate of global cognitive decline. However, when SSRI use and tangles were included in the same model, the association of SSRI use with rate of global cognitive decline was reduced by more than 50% and no longer statistically significant. SSRI use was associated with higher postmortem level of tau tangles, possibly because SSRI are being used to treat neurobehavioral symptoms associated with dementia, and this relationship appears to partly account for the association of SSRI use with more rapid cognitive decline.

Polygenic risk of major depressive disorder as a risk factor for venous thromboembolism

Major depressive disorder (MDD), bipolar disorder (BD), and schizophrenia (SCZ) are associated with an increased risk of cardiovascular diseases, including venous thromboembolism (VTE). The reasons for this are complex and include obesity, smoking, and use of hormones and psychotropic medications. Genetic studies have increasingly provided evidence of the shared genetic risk of psychiatric and cardiometabolic illnesses. This study aimed to determine whether a genetic predisposition to MDD, BD, or SCZ is associated with an increased risk of VTE. Genetic correlations using the largest genome-wide genetic meta-analyses summary statistics for MDD, BD, and SCZ (Psychiatric Genetics Consortium) and a recent genome-wide genetic meta-analysis of VTE (INVENT Consortium) demonstrated a positive association between VTE and MDD but not BD or SCZ. The same summary statistics were used to construct polygenic risk scores for MDD, BD, and SCZ in UK Biobank participants of self-reported White British ancestry. These were assessed for impact on self-reported VTE risk (10 786 cases, 285 124 controls), using logistic regression, in sex-specific and sex-combined analyses. We identified significant positive associations between polygenic risk for MDD and the risk of VTE in men, women, and sex-combined analyses, independent of the known risk factors. Secondary analyses demonstrated that this association was not driven by those with lifetime experience of mental illness. Meta-analyses of individual data from 6 additional independent cohorts replicated the sex-combined association. This report provides evidence for shared biological mechanisms leading to MDD and VTE and suggests that, in the absence of genetic data, a family history of MDD might be considered when assessing the risk of VTE.

Association between depression and macrovascular disease: a mini review

Depression and macrovascular diseases are globally recognized as significant disorders that pose a substantial socioeconomic burden because of their associated disability and mortality. In addition, comorbidities between depression and macrovascular diseases have been widely reported in clinical settings. Patients afflicted with coronary artery disease, cerebrovascular disease or peripheral artery disease exhibit an elevated propensity for depressive symptoms. These symptoms, in turn, augment the risk of macrovascular diseases, thereby reflecting a bidirectional relationship. This review examines the physiological and pathological mechanisms behind comorbidity while also examining the intricate connection between depression and macrovascular diseases. The present mechanisms are significantly impacted by atypical activity in the hypothalamic-pituitary-adrenal axis. Elevated levels of cortisol and other hormones may disrupt normal endothelial cell function, resulting in vascular narrowing. At the same time, proinflammatory cytokines like interleukin-1 and C-reactive protein have been shown to disrupt the normal function of neurons and microglia by affecting blood-brain barrier permeability in the brain, exacerbating depressive symptoms. In addition, platelet hyperactivation or aggregation, endothelial dysfunction, and autonomic nervous system dysfunction are important comorbidity mechanisms. Collectively, these mechanisms provide a plausible physiological basis for the interplay between these two diseases. Interdisciplinary collaboration is crucial for future research aiming to reveal the pathogenesis of comorbidity and develop customised prevention and treatment strategies.

The association between platelet reactivity and lipoprotein levels in Framingham Heart Study participants

BACKGROUND

Hypertriglyceridemia is an independent risk factor for major adverse cardiovascular events, though the mechanisms linking triglycerides and platelet function with thrombosis, remain elusive. The aim of this study was to assess the association between platelet function and triglyceride levels.

METHODS

We included participants from the Framingham Heart Study Third Generation cohort, OMNI, and New Offspring Spouse cohort who attended the third examination cycle (2016-2019). Eligible participants were categorized into four triglyceride subgroups.

RESULTS

The study comprised a total of 1897 (55.53 %) participants with normal TG levels; 883 (25.85 %) participants with high-normal TGs; 378 (11.07 %) with borderline high TGs; and 258 (7.55 %) participants with hypertriglyceridemia. After adjusting for age, sex, alcohol consumption, aspirin, statin and P2Y₁₂ inhibitors, the levels of ADP-induced platelet aggregation were inversely associated with total cholesterol levels (P < 0.0001). Platelet disaggregation was associated with low-density lipoprotein and high-density lipoprotein cholesterol levels (P < 0.0001). Lastly, in a shear-stress chamber assay mimicking arterial flow velocities, TG levels in the normal-high group were associated with increased levels of collagen-dependent thrombogenicity (β = 24.16, SE = 6.65, P < 0.0001).

CONCLUSION

Triglyceride levels are associated with altered platelet activation and aggregation. Furthermore, increased platelet-driven thrombogenicity is directly associated with triglyceride levels after adjusting for medications and other covariates.

Assessment of Platelet Function by High-Throughput Screening Light Transmission Aggregometry: Optimul Assay

Platelet function testing is critical in the diagnosis of bleeding disorders and allows monitoring of antiplatelet therapy. The gold standard assay, light transmission aggregometry (LTA), was developed 60 years ago and remains widely used worldwide. It requires, however, access to expensive equipment and is time-consuming, and the interpretation of results requires evaluation by an experienced investigator. It also suffers from a lack of standardization, resulting in widely variable results between laboratories. 96-well plate-based Optimul aggregometry utilizes the same principles of LTA and aims to standardize agonist concentrations with the development of 96-well plates which are precoated with 7 concentrations of each lyophilized agonist (arachidonic acid, adenosine diphosphate, collagen, epinephrine, TRAP-6 amide, and U46619) and stored at ambient room temperature (20-25 °C) for up to 12 weeks. For platelet function testing, 40 μL of platelet-rich plasma is added to each well, and the plate is placed onto a plate shaker, after which platelet aggregation is determined by changes in light absorbance. This method reduces the blood volume required and allows for in-depth platelet function analysis without specialist training, or the need to purchase expensive, dedicated equipment.