Randomized controlled trial comparing impact on platelet reactivity of twice-daily with once-daily aspirin in people with Type 2 diabetes

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.

Thromboxane biosynthesis and future events in diabetes: the ASCEND trial

BACKGROUND AND AIMS

Thromboxane (TX) A2, released by activated platelets, plays an important role in atherothrombosis. Urinary 11-dehydro-TXB2 (U-TXM), a stable metabolite reflecting the whole-body TXA2 biosynthesis, is reduced by ∼70% by daily low-dose aspirin. The U-TXM represents a non-invasive biomarker of in vivo platelet activation and is enhanced in patients with diabetes. This study assessed whether U-TXM is associated with the risk of future serious vascular events or revascularizations (SVE-R), major bleeding, or cancer in patients with diabetes.

METHODS

The U-TXM was measured pre-randomization to aspirin or placebo in 5948 people with type 1 or 2 diabetes and no cardiovascular disease, in the ASCEND trial. Associations between log U-TXM and SVE-R (n = 618), major bleed (n = 206), and cancer (n = 700) during 6.6 years of follow-up were investigated by Cox regression; comparisons of these associations with the effects of randomization to aspirin were made.

RESULTS

Higher U-TXM was associated with older age, female sex, current smoking, type 2 diabetes, higher body size, urinary albumin/creatinine ratio of ≥3 mg/mmol, and higher estimated glomerular filtration rate. After adjustment for these, U-TXM was marginally statistically significantly associated with SVE-R and major bleed but not cancer [hazard ratios per 1 SD higher log U-TXM (95% confidence interval): 1.09 (1.00-1.18), 1.16 (1.01-1.34), and 1.06 (0.98-1.14)]. The hazard ratio was similar to that implied by the clinical effects of randomization to aspirin for SVE-R but not for major bleed.

CONCLUSIONS

The U-TXM was log-linearly independently associated with SVE-R in diabetes. This is consistent with the involvement of platelet TXA2 in diabetic atherothrombosis.

10. Cardiovascular Disease and Risk Management: Standards of Care in Diabetes-2024

The American Diabetes Association (ADA) "Standards of Care in Diabetes" includes the ADA's current clinical practice recommendations and is intended to provide the components of diabetes care, general treatment goals and guidelines, and tools to evaluate quality of care. Members of the ADA Professional Practice Committee, an interprofessional expert committee, are responsible for updating the Standards of Care annually, or more frequently as warranted. For a detailed description of ADA standards, statements, and reports, as well as the evidence-grading system for ADA's clinical practice recommendations and a full list of Professional Practice Committee members, please refer to Introduction and Methodology. Readers who wish to comment on the Standards of Care are invited to do so at professional.diabetes.org/SOC.

Diabetes type 2: relationships between lysosomal exocytosis of circulating normal-sized platelets and in vitro ɑ-thrombin-evoked platelet responses

BACKGROUND/OBJECTIVE

Type 2 diabetes is a major risk factor for atherosclerotic disease. It is well agreed that the reactivity of diabetic platelets is increased but how platelet reactivity regulates is unknown. In our laboratory, density separated platelets have been investigated extensively and high- and low-density platelets circulate in an activated state. The density distribution of circulating platelets is altered in diabetes type 2 as well. We hypothesize that such platelets modify whole blood (WB) in vitro α-thrombin-evoked (10 μM/mL) activity in type 2 diabetes. Thus, the study aims to identify features of circulating normal-sized density subpopulations affecting whole blood (WB) platelet reactivity in type 2 diabetes.

PATIENTS AND METHODS

Patients with type 2 diabetes (n = 16) were enrolled. Their normal-sized platelets were divided into density subfractions (n = 16) using continuous polyvinylpyrrolidone-coated silica (Percoll™) gradients (density span, 1.090-1.040 kg/L) containing prostaglandin E₁. The proportions (%) of such density-separated platelets expressing lysosomal-associated membrane protein 1 (LAMP-1) were analyzed using a flow cytometer. Further, determinations of WB ɑ-thrombin-evoked (10 U/mL) surface LAMP-1 (an assessment of lysosomal release), the fibrinogen (α_IIbβ₃₎ receptor activity, annexin V (binds to exposed membrane phosphatidylserine), and mitochondrial transmembrane potentials (an estimate of organelle integrity) were performed. Surface LAMP-1 expressions of individual normal-sized platelet density subpopulations were stratified into equal-sized groups (n = 2) depending on reactivity, as judged from the ɑ-thrombin-induced WB activity markers.

RESULTS

With some exceptions, the proportion of normal-sized circulating platelets showing spontaneous LAMP-1 was strongly associated with WB ɑ-thrombin-evoked (10 U/mL) surface LAMP-1 and α_IIbβ₃ receptor activity. LAMP-1-expressing normal-sized platelets also displayed inverse associations with WB ɑ-thrombin-induced surface annexin V and mitochondrial damage, which are features of procoagulant platelets.

CONCLUSIONS

From the current descriptive work only involving type 2 diabetes, it is impossible to judge whether the findings are features of the disease or if they occur in healthy individuals as well. However, the study describes LAMP-1 expressing subpopulations of circulating normal-sized platelets that associate with WB α-thrombin (10 U/mL) responses in vitro. Increased proportions of such platelets induced lysosomal release and α_IIbβ₃ receptor activity, whereas lower proportions promoted WB agonist-induced procoagulant platelet creation. It is to hypothesize that the new described regulatory mechanism could in the future offer a possibility to influence platelet behavior in type 2 diabetes.Key messagesLysosomal exocytosis of circulating platelets influences reactivity, as determined by agonist-induced platelet reactions in vitroThus, the low release of lysosomes by normal-sized platelets in vivo increases agonist-evoked procoagulant platelet production.Higher lysosomal exocytosis of circulating normal-sized platelets promotes platelet aggregation and secretion.

The Cellular and Protein Arms of Coagulation in Diabetes: Established and Potential Targets for the Reduction of Thrombotic Risk

Diabetes is a metabolic condition with a rising global prevalence and is characterised by abnormally high blood glucose levels. Cardiovascular disease (CVD) accounts for the majority of deaths in diabetes and, despite improvements in therapy, mortality and hospitalisations in this cohort remain disproportionally higher compared to individuals with normal glucose metabolism. One mechanism for increased CVD risk is enhanced thrombosis potential, due to altered function of the cellular and acellular arms of coagulation. Different mechanisms have been identified that mediate disordered blood clot formation and breakdown in diabetes, including dysglycaemia, insulin resistance, and metabolic co-morbidities. Collectively, these induce platelet/endothelial dysfunction and impair the fibrinolytic process, thus creating a prothrombotic milieu. Despite these abnormalities, current antithrombotic therapies are largely similar in diabetes compared to those without this condition, which explains the high proportion of patients experiencing treatment failure while also displaying an increased risk of bleeding events. In this narrative review, we aimed to summarise the physiological functioning of haemostasis followed by the pathological effects of diabetes mellitus on platelets and the fibrin network. Moreover, we carefully reviewed the literature to describe the current and future therapeutic targets to lower the thrombosis risk and improve vascular outcomes in diabetes.

Effect of low-dose aspirin on urinary 11-dehydro-thromboxane B2 in the ASCEND (A Study of Cardiovascular Events iN Diabetes) randomized controlled trial

BACKGROUND

Aspirin is widely used for cardioprotection with its antiplatelet effects due to the blocking of thromboxane A2 production. However, it has been suggested that platelet abnormalities in those with diabetes prevent adequate suppression with once daily aspirin.

METHODS

In the ASCEND randomized double-blind trial of aspirin 100 mg once daily versus placebo in participants with diabetes but no history of cardiovascular disease, suppression was assessed by measuring 11-dehydro-thromboxane B2 excretion in urine (U-TXM) in a randomly selected sample of 152 participants (76 aspirin arm, 74 placebo arm), plus 198 (93 aspirin arm, 105 placebo arm) adherent to study drugs and selected to maximize the numbers ingesting their last tablet 12-24 h before urine sampling. U-TXM was assayed using a competitive ELISA assay in samples mailed a mean of 2 years after randomization, with time since taking last aspirin/placebo tablet recorded at the time of sample provision. Effective suppression (U-TXM < 1500 pg/mg creatinine) and percentage reductions in U-TXM by aspirin allocation were compared.

RESULTS

In the random sample, U-TXM was 71% (95% CI 64-76%) lower among aspirin vs placebo-allocated participants. Among adherent participants in the aspirin arm, U-TXM was 72% (95% CI 69-75%) lower than in the placebo arm and 77% achieved effective suppression overall. Suppression was similar among those who ingested their last tablet more than 12 h before urine sampling with levels in the aspirin arm 72% (95% CI 67-77%) lower than in the placebo arm and 70% achieving effective suppression.

CONCLUSIONS

Daily aspirin significantly reduces U-TXM in participants with diabetes, including at 12-24 h after ingestion.

TRIAL REGISTRATION

ISRCTN ISRCTN60635500. Registered on 1 Sept 2005; ClinicalTrials.gov NCT00135226. Registered on 24 Aug 2005.

10. Cardiovascular Disease and Risk Management: Standards of Care in Diabetes-2023

The American Diabetes Association (ADA) "Standards of Care in Diabetes" includes the ADA's current clinical practice recommendations and is intended to provide the components of diabetes care, general treatment goals and guidelines, and tools to evaluate quality of care. Members of the ADA Professional Practice Committee, a multidisciplinary expert committee, are responsible for updating the Standards of Care annually, or more frequently as warranted. For a detailed description of ADA standards, statements, and reports, as well as the evidence-grading system for ADA's clinical practice recommendations and a full list of Professional Practice Committee members, please refer to Introduction and Methodology. Readers who wish to comment on the Standards of Care are invited to do so at professional.diabetes.org/SOC.

Questions and answers on the use of aspirin for primary prevention of cardiovascular disease in diabetes

Patients with diabetes have a prothrombotic state and a 2 to 4 times higher risk of cardiovascular events than those without diabetes. Aspirin is the cornerstone of treatment in patients withcardiovascular disease, irrespective of diabetes status, being able to confer a 19% relative risk reduction per year in serious vascular events compared with placebo at long-term follow-up (6.7% vs 8.2% per year, p < 0.0001). Data regarding the benefit-risk ratio of aspirin prescribed to patients with diabetes without established cardiovascular disease are less convincing, especially when compared to other preventive strategies. Of note, in primary prevention trials, aspirin allocation yielded a significant 12% proportional reduction in serious vascular events, irrespective of diabetes status, corresponding to a small annual absolute risk reduction (0.06% per year). However, in everyday clinical practice aspirin is still largely prescribed by both diabetologists and cardiologists. In this article, we provide eight questions and answers corroborated by available evidence on the use of aspirin for primary prevention of cardiovascular disease in diabetes.

Cardiovascular disease in type 2 diabetes mellitus: progress toward personalized management

Cardiovascular diseases (CVDs) are the main cause of death among patients with type 2 diabetes mellitus (T2DM), particularly in low- and middle-income countries. To effectively prevent the development of CVDs in T2DM, considerable effort has been made to explore novel preventive approaches, individualized glycemic control and cardiovascular risk management (strict blood pressure and lipid control), together with recently developed glucose-lowering agents and lipid-lowering drugs. This review mainly addresses the important issues affecting the choice of antidiabetic agents and lipid, blood pressure and antiplatelet treatments considering the cardiovascular status of the patient. Finally, we also discuss the changes in therapy principles underlying CVDs in T2DM.

Aspirin for Primary Cardiovascular Prevention in Patients with Diabetes: Uncertainties and Opportunities

The use of the antiplatelet agent aspirin (acetylsalicylic acid) was previously routinely recommended for the primary prevention of cardiovascular (CV) events in patients with diabetes, but recent large-scale randomized trials have failed to demonstrate a sizeable net clinical benefit with a once-daily, low-dose (81–100 mg) regimen in this population. Previous pharmacokinetic and pharmacodynamic studies have suggested that the aspirin formulation (enteric-coated) and dosing schedule (once daily) studied in randomized trials for primary prevention of CV events defining contemporary clinical practice may not leverage the full potential of the drug, particularly in patients with diabetes. Indeed, the diabetic platelets bear characteristics that increase their thrombotic potential and alter their pharmacologic response to the drug. Consequently, the appropriateness of studying a uniform aspirin regimen in landmark primary prevention trials needs to be revisited. In this review, we present the evidence showing that diabetes not only increases baseline platelet reactivity, but also alters platelet response to aspirin through different mechanisms including a faster platelet turnover rate. Obesity, which is frequently associated with diabetes, also impacts its pharmacokinetics via an increase in distribution volume. Small-scale pharmacokinetic and pharmacodynamic studies have suggested that the relative aspirin resistance phenotype observed in patients with diabetes may be reversed with a twice-daily dosing schedule, and with nonenteric-coated aspirin formulations. Properly powered randomized controlled trials investigating the efficacy and safety of aspirin dosing schedules and formulations tailored to the population of patients with diabetes are urgently required to optimize patient care.

Comprehensive Management of Cardiovascular Risk Factors for Adults With Type 2 Diabetes: A Scientific Statement From the American Heart Association

Cardiovascular disease remains the leading cause of death in patients with diabetes. Cardiovascular disease in diabetes is multifactorial, and control of the cardiovascular risk factors leads to substantial reductions in cardiovascular events. The 2015 American Heart Association and American Diabetes Association scientific statement, "Update on Prevention of Cardiovascular Disease in Adults With Type 2 Diabetes Mellitus in Light of Recent Evidence," highlighted the importance of modifying various risk factors responsible for cardiovascular disease in diabetes. At the time, there was limited evidence to suggest that glucose-lowering medications reduce the risk of cardiovascular events. At present, several large randomized controlled trials with newer antihyperglycemic agents have been completed, demonstrating cardiovascular safety and reduction in cardiovascular outcomes, including cardiovascular death, myocardial infarction, stroke, and heart failure. This AHA scientific statement update focuses on (1) the evidence and clinical utility of newer antihyperglycemic agents in improving glycemic control and reducing cardiovascular events in diabetes; (2) the impact of blood pressure control on cardiovascular events in diabetes; and (3) the role of newer lipid-lowering therapies in comprehensive cardiovascular risk management in adults with diabetes. This scientific statement addresses the continued importance of lifestyle interventions, pharmacological therapy, and surgical interventions to curb the epidemic of obesity and metabolic syndrome, important precursors of prediabetes, diabetes, and comorbid cardiovascular disease. Last, this scientific statement explores the critical importance of the social determinants of health and health equity in the continuum of care in diabetes and cardiovascular disease.

10. Cardiovascular Disease and Risk Management: Standards of Medical Care in Diabetes-2022

The American Diabetes Association (ADA) "Standards of Medical Care in Diabetes" includes the ADA's current clinical practice recommendations and is intended to provide the components of diabetes care, general treatment goals and guidelines, and tools to evaluate quality of care. Members of the ADA Professional Practice Committee, a multidisciplinary expert committee (https://doi.org/10.2337/dc22-SPPC), are responsible for updating the Standards of Care annually, or more frequently as warranted. For a detailed description of ADA standards, statements, and reports, as well as the evidence-grading system for ADA's clinical practice recommendations, please refer to the Standards of Care Introduction (https://doi.org/10.2337/dc22-SINT). Readers who wish to comment on the Standards of Care are invited to do so at professional.diabetes.org/SOC.

Contemporary Clinical Use of Aspirin: Mechanisms of Action, Current Concepts, Unresolved Questions, and Future Perspectives

The ability of aspirin to inhibit platelet aggregation has positioned this agent within the most frequently used drugs worldwide. The aim of this article is to review the contemporary clinical use of aspirin and also to discuss unresolved issues not yet translated into clinical practice. Results from several clinical trials have led to strong guideline recommendations for aspirin use in the acute management and secondary prevention of cardiovascular disease. On the contrary, guidelines regarding aspirin use as primary prevention of cardiovascular disease are almost conservative, supported by recent trials reporting that the bleeding risk outweighs the potential benefits in most patients. In pregnancy, aspirin has proved efficient in preventing preeclampsia and small-for-gestational-age births in women at high risk, and is hence widely recommended in clinical guidelines. Despite the vast amount of clinical data on aspirin, several unresolved questions remain. Randomized trials have reported that aspirin reduces the risk of recurrent venous thromboembolism, but the clinical relevance remains limited, because direct oral anticoagulants are more effective. Laboratory studies suggest that a twice-daily dosing regimen or evening intake may lead to more efficient platelet inhibition, and the potential clinical benefit of such strategies is currently being explored in ongoing clinical trials. Enteric-coated formulations of aspirin are frequently used, but it remains unclear if they are safer and as efficient as plain aspirin. In the future, aspirin use after percutaneous coronary interventions might not be mandatory in patients who also need anticoagulant therapy, as several trials support shorter aspirin duration strategies. On the other hand, new treatment indications for aspirin will likely arise, as there is growing evidence that aspirin may reduce the risk of colorectal cancer and other types of cancer.

Aspirin for Primary Prevention of Cardiovascular Disease in the 21st Century: A Review of the Evidence

Aspirin (ASA) is the most commonly prescribed antiplatelet agent. Although the evidence for efficacy of aspirin for secondary prevention of ischemic events in patients with established cardiovascular disease is strong, its role in primary prevention has been subject of controversies over the past decades. In fact, historical trials have shown only modest benefit in terms of reduction of ischemic events, mostly myocardial infarction and to a lesser extent stroke, and only at the expense of an increased risk of bleeding. These observations have led to divergent recommendations from professional societies on the use of ASA for primary prevention of cardiovascular disease manifestations. However, recent results from three trials of primary prevention have shown either no benefit or modest benefit on combined ischemic end points, without any impact on hard cardiovascular events such as myocardial infarction or stroke, accompanied by an increased risk of bleeding. Overall, this translated into neutral net benefit or even harm with the use of aspirin in patients with no overt cardiovascular disease. These results have accordingly led to a downgrade in the current recommendations on the use of ASA for primary prevention. This article provides an overview on the current evidence on the use of aspirin for primary prevention of cardiovascular disease.

10. Cardiovascular Disease and Risk Management: Standards of Medical Care in Diabetes-2021

The American Diabetes Association (ADA) "Standards of Medical Care in Diabetes" includes the ADA's current clinical practice recommendations and is intended to provide the components of diabetes care, general treatment goals and guidelines, and tools to evaluate quality of care. Members of the ADA Professional Practice Committee, a multidisciplinary expert committee (https://doi.org/10.2337/dc21-SPPC), are responsible for updating the Standards of Care annually, or more frequently as warranted. For a detailed description of ADA standards, statements, and reports, as well as the evidence-grading system for ADA's clinical practice recommendations, please refer to the Standards of Care Introduction (https://doi.org/10.2337/dc21-SINT). Readers who wish to comment on the Standards of Care are invited to do so at professional.diabetes.org/SOC.

Once- versus Twice-Daily Aspirin in Patients at High Risk of Thrombotic Events: Systematic Review and Meta-Analysis

BACKGROUND

Acetylsalicylic acid (ASA) is a frequently used antiplatelet agent, although some individuals have reduced antiplatelet responses on ASA, with recurrent ischemic events. It has been proposed that shortening the ASA dosing interval may overcome the time-dependent renewal of the drug target, leading to a greater antiplatelet effect. We conducted a systematic review of randomized controlled trials (RCTs) to determine the efficacy of once- versus twice-daily ASA in conditions with increased platelet turnover.

METHODS

We conducted a systematic review and meta-analysis by searching the CENTRAL, MEDLINE, and Embase databases for RCTs assessing once- versus twice-daily ASA. Data were screened, extracted, and appraised by two independent reviewers, and were pooled using a random-effects model. The primary outcomes were major adverse cardiovascular events (MACEs) and serum thromboxane B2 (TxB2). Other pharmacodynamic measures were retrieved as secondary outcomes. Results were reported as mean differences with corresponding 95% confidence intervals (CIs). We followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines.

RESULTS

Seven RCTs were included, enrolling 379 participants overall. None of the studies reported clinical outcomes. Pooled results showed that compared with once-daily ASA, twice-daily ASA was associated with a decrease in mean TxB2 of 1.42 ng/mL (95% CI - 2.71 to - 0.13; I² = 66%). We found no differences in subgroup analyses based on disease subtype, trial blinding, or trial design. A greater antiplatelet activity of the twice-daily regimen was also found when using PFA-100-ADP methods, although not when using the VerifyNow, LTA-AA, and multiplate methods.

CONCLUSIONS

Twice-daily ASA was associated with a greater antiplatelet effect compared with standard once-daily ASA.

Metabolic Syndrome and the Effectiveness of Low-dose Aspirin on Reproductive Outcomes

BACKGROUND

Metabolic syndrome is associated with increases in both inflammation and aspirin resistance, but effectiveness of aspirin in improving reproductive health among women with metabolic syndrome is unknown. We evaluated the effectiveness of low-dose aspirin in improving reproductive outcomes across metabolic syndrome score.

METHODS

The EAGeR trial randomly assigned 1228 women with a history of pregnancy loss to receive 81 mg aspirin or placebo for up to six menstrual cycles of attempting pregnancy and, if they became pregnant, throughout pregnancy. We assessed components of metabolic syndrome at enrollment, including: waist circumference ≥88 cm, triglycerides ≥150 mg/dl, high-density lipoprotein ≤50 mg/dl, blood pressure ≥130 mmHg systolic or ≥85 mmHg diastolic, and glucose ≥100 mg/dl. We summed components to calculate metabolic syndrome score.

RESULTS

A total of 229 participants (20%) met full criteria for metabolic syndrome, 207 (18%) had two components, 366 (31%) one component, and 372 (32%) no components. Among those without any component of metabolic syndrome, aspirin was associated with 10.7 [95% confidence interval (CI) = 1.2, 20.2] more pregnancies and 13.7 (95% CI = 3.3, 24.0) more live births per 100 couples. Effects were attenuated as metabolic syndrome score increased and we observed no clear effect of aspirin on pregnancy or live birth among women with metabolic syndrome.

CONCLUSIONS

Low-dose aspirin is most effective in increasing pregnancy and live birth among women with no or few components of metabolic syndrome. Reduced effectiveness among women with metabolic syndrome may be due to differences in effective dose or aspirin resistance.

Diabetes and Vascular Disease: Is It All About Glycemia?

BACKGROUND

Diabetes is increasing over time, mainly driven by obesity, aging, and urbanization. Classical macro- and microvascular complications represent the final result of a complex interplay involving atherosclerosis at all stages.

METHODS

In this review, we aim at focusing on current updates in the pathophysiology of vascular disease in diabetes and discussing how new therapies might influence the management of these patients at high cardiovascular risk. Diabetes shows accelerated atherosclerosis with a larger inflammatory cell infiltrate, thus favoring the development of heart failure. 'Diabetic cardiomyopathy' perfectly describes a specific ischemia- and hypertension- independent entity due to diabetes-related metabolic alterations on myocardial function. Moreover, platelets from subjects with diabetes display a typical hyperreactivity explaining the stronger adhesion, activation, and aggregation. Additionally, diabetes provokes an exaggerated stimulation of the endothelium, with an increased release of reactive oxygen species and a reduced release of nitric oxide, both key elements of the endothelial dysfunction. Also, the coagulation cascade and leukocytes activate contributing to this pro-thrombotic environment. Neutrophils have been recently recognized to play a pivotal role by releasing neutrophil extracellular traps. Finally, microparticles from platelets, neutrophils or monocytes are detrimental effectors on the vessel wall and are involved both in vascular dysfunction and in thrombotic complications.

CONCLUSION

In light of these findings, the therapeutic management of diabetes needs to be mostly focused on limiting the progression of complications by targeting precise pathophysiological mechanisms rather than the mere glycemic control, which failed to markedly reduce the risk for macrovascular complications and mortality.

Antiplatelet therapies in diabetes

Cardiovascular complications remain the main cause of mortality and morbidity in diabetes. This is related to advanced vascular pathology in this population, together with an enhanced thrombotic environment. The increased risk in thrombosis is secondary to platelet hyper-reactivity and increased levels and/or altered activity of coagulation factors. The current review is focused on the role of antiplatelet agents in modulating the thrombotic milieu in diabetes and improving vascular outcome in this high-risk population. We review the latest evidence for the use of aspirin in primary vascular prevention together with long-term treatment with this agent for secondary prevention. We also discuss the effects of the various P2Y₁₂ inhibitors, including clopidogrel, prasugrel and ticagrelor, on both short- and long-term secondary vascular prevention. Moreover, we briefly review antiplatelet therapies in special groups of people including those intolerant to aspirin, individuals with peripheral vascular disease and those with cerebrovascular pathology. The overall aim of this review is to provide the healthcare professional with a pragmatic guide for the management of thrombotic risk using established antiplatelet therapies to improve vascular outcome in persons with diabetes.

Clinical Management of Stable Coronary Artery Disease in Patients With Type 2 Diabetes Mellitus: A Scientific Statement From the American Heart Association

Although cardiologists have long treated patients with coronary artery disease (CAD) and concomitant type 2 diabetes mellitus (T2DM), T2DM has traditionally been considered just a comorbidity that affected the development and progression of the disease. Over the past decade, a number of factors have shifted that have forced the cardiology community to reconsider the role of T2DM in CAD. First, in addition to being associated with increased cardiovascular risk, T2DM has the potential to affect a number of treatment choices for CAD. In this document, we discuss the role that T2DM has in the selection of testing for CAD, in medical management (both secondary prevention strategies and treatment of stable angina), and in the selection of revascularization strategy. Second, although glycemic control has been recommended as a part of comprehensive risk factor management in patients with CAD, there is mounting evidence that the mechanism by which glucose is managed can have a substantial impact on cardiovascular outcomes. In this document, we discuss the role of glycemic management (both in intensity of control and choice of medications) in cardiovascular outcomes. It is becoming clear that the cardiologist needs both to consider T2DM in cardiovascular treatment decisions and potentially to help guide the selection of glucose-lowering medications. Our statement provides a comprehensive summary of effective, patient-centered management of CAD in patients with T2DM, with emphasis on the emerging evidence. Given the increasing prevalence of T2DM and the accumulating evidence of the need to consider T2DM in treatment decisions, this knowledge will become ever more important to optimize our patients' cardiovascular outcomes.

Hypoglycaemia leads to a delayed increase in platelet and coagulation activation markers in people with type 2 diabetes treated with metformin only: Results from a stepwise hypoglycaemic clamp study

AIMS

To investigate the effect of hypoglycaemia on platelet and coagulation activation in people with type 2 diabetes.

MATERIALS AND METHODS

This monocentric, open, single-arm, mechanistic trial included 14 people with established type 2 diabetes (four women, 10 men, age 55 ± 7 years, glycated haemoglobin concentration 51 ± 7 mmol/mol) receiving metformin monotherapy. A stepwise hyperinsulinaemic-hypoglycaemic clamp experiment (3.5 and 2.5 mmol/L, for 30 minutes respectively) was performed, aiming to investigate platelet and coagulation activity during predefined plateaus of hypoglycaemia, as well as 1 day and 7 days later.

RESULTS

While platelet activation assessed by light transmittance aggregometry did not significantly increase after the hypoglycaemic clamp procedure, the more sensitive flow cytometry-based measurement of platelet surface activation markers showed hypoglycaemia-induced activation 24 hours (PAC1^pos CD62P^pos , PAC1^pos CD63P^pos and PAC1^pos CD62P^pos CD63^pos ; P < .01) and 7 days after the hypoglycaemic clamp (P < .001 for PAC1^pos CD63^pos ; P < .01 for PAC1^pos CD62P^pos and PAC1^pos CD62P^pos CD63^pos ) in comparison to baseline. Coagulation markers, such as fibrinogen, D-dimer, plasminogen activator inhibitor-1, von Willebrand factor activity and factor VIII, were also significantly increased, an effect that was most pronounced 24 hours after the hypoglycaemic clamp.

CONCLUSION

A single event of insulin-induced hypoglycaemia led to an increase in markers of platelet activation and coagulation in people with early stages of type 2 diabetes on metformin therapy. However, the activation occurred with a delay and was evident 24 hours and 7 days after the actual hypoglycaemic episode.

Aspirin in the primary prevention of cardiovascular disease in diabetes mellitus: A new perspective

Although the improved control of hyperglycaemia and other cardiovascular risk factors was associated with a parallel decline of atherosclerotic cardiovascular disease (ASCVD) and death in both type 1 (T1) and type 2 (T2) diabetes mellitus (DM), the burden of death and hospitalization for ASCVD remains significantly higher by about 2-fold versus the matched non-DM population. Life style interventions, such as physical activity and healthy diet, and drugs, such as statins and low-dose aspirin, may have beneficial effects by targeting one or multiple pathways responsible for accelerated atherosclerosis and its thrombotic complications. The debate on the benefit-risk balance of primary cardiovascular prevention with aspirin has been especially vivacious over the past two years, following the publication of three large randomized, placebo-controlled, primary prevention trials in different settings, spanning from healthy elderly to DM subjects. The aim of this review is to discuss the pathophysiological, pharmacological and clinical evidence supporting the appropriate use of low-dose aspirin in DM, within the context of the current multifactorial approach to primary cardiovascular prevention.

All-cause mortality following low-dose aspirin treatment for patients with high cardiovascular risk in remote Australian Aboriginal communities: an observational study

OBJECTIVES

To evaluate the benefit and risk of low-dose acetylsalicylic acid (aspirin) in patients from remote Aboriginal communities in the Northern Territory, Australia.

DESIGN

Retrospective cohort study using primary care and hospital data routinely used for healthcare. Aspirin users and non-users were compared before and after controlling confounders by matching. Marginal structural models (MSM) were applied to ascertain the benefit and risk.

SETTING

The benefit and harm of aspirin were investigated in patients aged ≥18 years from 54 remote Aboriginal communities.

PARTICIPANTS

None had a previous cardiovascular event or major bleeds. Patients on anticoagulants or other antiplatelets were excluded.

INTERVENTION

Aspirin at a dose of 75-162 mg/day.

OUTCOME MEASURES

Endpoints were all-cause, cardiovascular mortality and incidences of cardiovascular events and major bleeds.

RESULTS

8167 predominantly Aboriginal adults were included and followed between July 2009 and June 2017 (aspirin users n=1865, non-users n=6302, mean follow-up 4 years with hospitalisations 6.4 per person). Univariate analysis found material differences in demographics, prevalence of chronic diseases and outcome measures between aspirin users and non-users before matching. After matching, aspirin was significantly associated with reduced all-cause mortality (HR=0.45: 95% CI 0.34 to 0.60; p<0.001), but not bleeding (HR=1.13: 95% CI 0.39 to 3.26; p=0.820). After using MSMs to eliminate the effects of confounders, loss of follow-up and time dependency of treatment, aspirin was associated with reduced all-cause mortality (HR=0.60: 95% CI 0.47 to 0.76; p<0.001), independent of age (HR=1.06; p<0.001), presence of diabetes (HR=1.42; p<0.001), hypertension (HR=1.61; p<0.001) and alcohol abuse (HR=1.81; p<0.001). No association between aspirin and major bleeding was found (HR=1.14: 95% CI 0.48 to 2.73; p=0.765). Sensitivity analysis suggested these findings were unlikely to have been the result of unmeasured confounding.

CONCLUSION

Aspirin was associated with reduced all-cause mortality. Bleeding risk was less compared with survival benefits. Aspirin should be considered for primary prevention in Aboriginal people with high cardiovascular risk.

Measurement of Thromboxane Biosynthesis in Health and Disease

Thromboxane (TX) A₂ is a chemically unstable lipid mediator involved in several pathophysiologic processes, including primary hemostasis, atherothrombosis, inflammation, and cancer. In human platelets, TXA₂ is the major arachidonic acid derivative via the cyclooxygenase (COX)-1 pathway. Assessment of platelet TXA₂ biosynthesis can be performed ex vivo through measurement of serum TXB₂, an index of platelet COX-1 activity, as well as in vivo through measurement of urinary enzymatic metabolites, a non-invasive index of platelet activation. This article reviews the main findings of four decades of clinical investigation based on these analytical approaches, focusing on the measurement of TXA₂ metabolites to characterize the pathophysiologic role of transiently or persistently enhanced platelet activation and to describe the clinical pharmacology of COX-1 inhibition in health and disease.

Aspirin for Primary Prevention of Cardiovascular Disease in Diabetes: a Review of the Evidence

PURPOSE OF REVIEW

People with diabetes are at a higher risk of atherosclerotic cardiovascular disease (ASCVD) compared with those without diabetes. Though aspirin has been shown to have an overall net clinical benefit when used for secondary prevention of ASCVD in people with and without diabetes, the evidence for primary prevention, especially in those with diabetes, remains inconsistent. In this article, we review the latest studies examining the risks and benefits of aspirin use for primary prevention of ASCVD in adults with diabetes, discuss key aspects in assessing the risk-benefit ratio of aspirin use for primary prevention of ASCVD, and summarize current guidelines from professional societies on aspirin use for primary prevention in adults with diabetes.

RECENT FINDINGS

In the general population, past studies have shown no difference in the beneficial effect of aspirin for primary cardiovascular disease prevention by diabetes status. However, several randomized controlled studies and meta-analyses in adults with diabetes have shown lack of net clinical benefit of aspirin use for primary prevention of ASCVD. The recent ASCEND trial documented cardiovascular benefit of aspirin for primary prevention in adults with diabetes but suggested that the increased risk of bleeding may outweigh the cardiovascular benefit. The decision to initiate aspirin for primary prevention of ASCVD must be considered carefully on an individual basis to balance the cardiovascular benefit and bleeding risk in all patients, especially those with diabetes. A multifactorial approach that focuses on managing ASCVD risk factors such as hypertension, dyslipidemia, dysglycemia, and smoking is recommended in all patients. More research is needed to identify subgroups of people with diabetes who are more likely to benefit from aspirin use for primary prevention of ASCVD and develop better antithrombotic strategies that shift the risk-benefit balance toward an overall net clinical benefit.

Aspirin alleviates orthopedic implant‑associated infection

Implant-associated infection (IAI), a common condition marked by progressive inflammation and bone destruction, is mentally and financially devastating to those it affects, causing severe morbidity, prolonged hospital admissions, significant hospital costs and, in certain cases, mortality. Aspirin, a popular synthetic compound with a history of >100 years, is antipyretic, anti-inflammatory and analgesic. It is the most active component of non-steroidal anti-inflammatory drugs. However, the effects of aspirin on IAI remain unknown. In the present study, an IAI animal model was used, in which a stainless steel pin coated with Staphylococcus aureus was implanted through the left shaft of the tibia in mice. The animals were then randomized into five groups and subjected respectively to IAI, IAI + 15 mg aspirin treatment, IAI + 30 mg aspirin treatment, IAI + 60 mg aspirin treatment and IAI + 120 mg aspirin treatment groups. Aspirin was injected intraperitoneally twice daily for 11 days. Micro-CT and histological assays were performed to assess the effects of aspirin on IAI. It was found that aspirin reduced osteolysis and periosteal reaction, inhibited the activation of osteoclasts, promoted the activation of osteoblasts and facilitated healing of the infected fracture.

Prevention of atherothrombotic events in patients with diabetes mellitus: from antithrombotic therapies to new-generation glucose-lowering drugs

Diabetes mellitus is an important risk factor for a first cardiovascular event and for worse outcomes after a cardiovascular event has occurred. This situation might be caused, at least in part, by the prothrombotic status observed in patients with diabetes. Therefore, contemporary antithrombotic strategies, including more potent agents or drug combinations, might provide greater clinical benefit in patients with diabetes than in those without diabetes. In this Consensus Statement, our Working Group explores the mechanisms of platelet and coagulation activity, the current debate on antiplatelet therapy in primary cardiovascular disease prevention, and the benefit of various antithrombotic approaches in secondary prevention of cardiovascular disease in patients with diabetes. While acknowledging that current data are often derived from underpowered, observational studies or subgroup analyses of larger trials, we propose antithrombotic strategies for patients with diabetes in various cardiovascular settings (primary prevention, stable coronary artery disease, acute coronary syndromes, ischaemic stroke and transient ischaemic attack, peripheral artery disease, atrial fibrillation, and venous thromboembolism). Finally, we summarize the improvements in cardiovascular outcomes observed with the latest glucose-lowering drugs, and on the basis of the available evidence, we expand and integrate current guideline recommendations on antithrombotic strategies in patients with diabetes for both primary and secondary prevention of cardiovascular disease.

10. Cardiovascular Disease and Risk Management: Standards of Medical Care in Diabetes-2019

The American Diabetes Association (ADA) "Standards of Medical Care in Diabetes" includes ADA's current clinical practice recommendations and is intended to provide the components of diabetes care, general treatment goals and guidelines, and tools to evaluate quality of care. Members of the ADA Professional Practice Committee, a multidisciplinary expert committee, are responsible for updating the Standards of Care annually, or more frequently as warranted. For a detailed description of ADA standards, statements, and reports, as well as the evidence-grading system for ADA's clinical practice recommendations, please refer to the Standards of Care Introduction Readers who wish to comment on the Standards of Care are invited to do so at professional.diabetes.org/SOC.

Aspirin in primary prevention for patients with diabetes: Still a matter of debate

BACKGROUND

Patients with diabetes are at high cardiovascular (CV) risk due to an exaggerated platelet activation and aggregation. In the first 2000s low-dose aspirin was first recommended for primary prevention, but then re-discussed.

METHODS

This short narrative review, based on the material searched for and obtained via PubMed up to February 2018, aims at clarifying this controversial topic.

RESULTS

The JPAD2 study has been designed to evaluate the occurrence of any CV event in a cohort of patients with diabetes and concluded that low-dose aspirin did not influence the risk for CV events while increasing the risk for gastrointestinal (GI) bleeding. Reasons for this result can be found in the role of diabetic platelets, which are known to be hyperreactive, thus producing intensified adhesion, activation, and aggregation. In this setting, other associated metabolic conditions can concur to enhance platelet adhesion and activation. Aspirin resistance has been often considered a guilty actor, although many mechanisms have been mistaken for true aspirin resistance, such as patient poor compliance, inadequate dosing, drug interactions, and high-platelet turnover. However, the mere presence of diabetes is not likely to give a net benefit for CV protection with respect to GI bleeding.

CONCLUSION

It appears advisable to follow current guidelines addressing first of all classical risk factors and evaluate aspirin therapy in primary prevention only for patients with type 1 or 2 diabetes at increased CV risk and no risk for GI bleeding. Anyway, additional clinical trials are needed to address the current topic.

Thrombosis and Vascular Inflammation in Diabetes: Mechanisms and Potential Therapeutic Targets

Cardiovascular disease remains the main cause of morbidity and mortality in patients with diabetes. The risk of vascular ischemia is increased in this population and outcome following an event is inferior compared to individuals with normal glucose metabolism. The reasons for the adverse vascular profile in diabetes are related to a combination of more extensive atherosclerotic disease coupled with an enhanced thrombotic environment. Long-term measures to halt the accelerated atherosclerotic process in diabetes have only partially addressed vascular pathology, while long-term antithrombotic management remains largely similar to individuals without diabetes. We address in this review the pathophysiological mechanisms responsible for atherosclerosis with special emphasis on diabetes-related pathways. We also cover the enhanced thrombotic milieu, characterized by increased platelet activation, raised activity of procoagulant proteins together with compromised function of the fibrinolytic system. Potential new therapeutic targets to reduce the risk of atherothrombosis in diabetes are explored, including alternative use of existing therapies. Special emphasis is placed on diabetes-specific therapeutic targets that have the potential to reduce vascular risk while keeping an acceptable clinical side effect profile. It is now generally acknowledged that diabetes is not a single clinical entity but a continuum of various stages of the condition with each having a different vascular risk. Therefore, we propose that future therapies aiming to reduce vascular risk in diabetes require a stratified approach with each group having a "stage-specific" vascular management strategy. This "individualized care" in diabetes may prove to be essential to improve vascular outcome in this high risk population.

9. Cardiovascular Disease and Risk Management: Standards of Medical Care in Diabetes-2018

The American Diabetes Association (ADA) "Standards of Medical Care in Diabetes" includes ADA's current clinical practice recommendations and is intended to provide the components of diabetes care, general treatment goals and guidelines, and tools to evaluate quality of care. Members of the ADA Professional Practice Committee, a multidisciplinary expert committee, are responsible for updating the Standards of Care annually, or more frequently as warranted. For a detailed description of ADA standards, statements, and reports, as well as the evidence-grading system for ADA's clinical practice recommendations, please refer to the Standards of Care Introduction Readers who wish to comment on the Standards of Care are invited to do so at professional.diabetes.org/SOC.

Antiplatelet effect of aspirin during 24h in patients with type 2 diabetes without cardiovascular disease

INTRODUCTION

The antiplatelet effect of low-dose aspirin in patients with type 2 diabetes (T2DM) without cardiovascular disease (CVD) has not been thoroughly explored. We investigated if platelet aggregation increased during the standard 24-hour aspirin dosing interval in patients with T2DM compared to non-diabetic controls. Furthermore, we evaluated baseline platelet aggregation, the acute effects of aspirin on platelet aggregation and platelet turnover.

MATERIALS AND METHODS

We included 21 patients with T2DM and 21 age and sex-matched controls. Platelet aggregation was measured by impedance aggregometry (Multiplate® Analyzer) and markers of platelet turnover by flow cytometry (Sysmex® XE-5000). Blood samples were obtained at baseline and 1h after administration of 75mg of aspirin. Participants were then treated for 6days with once-daily aspirin, and blood sampling was repeated 1h and 24h after aspirin intake.

RESULTS

After 6days of treatment, platelet aggregation levels increased during the 24-hour aspirin dosing interval in both patients and controls (p<0.001) with no difference between patients and controls. At baseline, patients with diabetes had increased platelet aggregation compared to controls (p=0.03). Platelet aggregation was reduced after the first dose of aspirin and significantly further reduced after six days of treatment (p<0.001). Patients with T2DM had numerically higher immature platelet count compared to controls (p=0.09), indicating an increased platelet turnover.

CONCLUSION

Patients with T2DM without a history of CVD and controls had increased platelet aggregation at the end of the standard 24-hour dosing interval of aspirin. Further, aspirin-naïve T2DM patients had increased platelet aggregation compared to controls.

Platelet indices and glucose control in type 1 and type 2 diabetes mellitus: A case-control study

BACKGROUND AND AIMS

The relationship between platelet indices and glucose control may differ in type 1 (T1DM) and type 2 (T2DM) diabetes. We aimed to investigate differences in mean platelet volume (MPV), platelet count, and platelet mass between patients with T1DM, T2DM, and healthy controls and to explore associations between these platelet indices and glucose control.

METHODS AND RESULTS

A total of 691 T1DM and 459 T2DM patients and 943 control subjects (blood donors) were included. HbA1c was measured in all subjects with diabetes and 36 T1DM patients further underwent 24 h-continuous glucose monitoring to estimate short-term glucose control (glucose mean and standard deviation). Adjusting for age and sex, platelet count was higher and MPV lower in both T1DM and T2DM patients vs control subjects, while platelet mass (MPV × platelet count) resulted higher only in T2DM. Upon further adjustment for HbA1c, differences in platelet count and mass were respectively 19.5 × 10⁹/L (95%CI: 9.8-29.3; p < 0.001) and 101 fL/nL (12-191; p = 0.027) comparing T2DM vs T1DM patients. MPV and platelet count were significantly and differently related in T2DM patients vs both T1DM and control subjects; this difference was maintained also accounting for HbA1c, age, and sex. Platelet mass and the volume-count relationship were significantly related to HbA1c only in T1DM patients. No associations were found between platelet indices and short-term glucose control.

CONCLUSION

By accounting for confounders and glucose control, our data evidenced higher platelet mass and different volume-count kinetics in subjects with T2DM vs T1DM. Long-term glucose control seemed to influence platelet mass and the volume-count relationship only in T1DM subjects. These findings suggest different mechanisms behind platelet formation in T1DM and T2DM patients with long-term glycaemic control being more relevant in T1DM than T2DM.

In Silico Modeling of the Antiplatelet Pharmacodynamics of Low-dose Aspirin in Health and Disease

The influence of platelet turnover on cyclooxygenase (COX-1) inhibition by low-dose aspirin remains largely uncharacterized due to limited feasibility of studying aspirin pharmacodynamics in bone marrow precursors. We developed an in silico compartmental model describing the aspirin effects on COX-1 activity in a population of megakaryocytes (MK) and in peripheral platelets. Model parameters were inferred from the literature and calibrated using measurements of serum thromboxane B₂ (sTXB₂ ), as proxy of COX-1 activity in peripheral platelets, in 17 healthy subjects and 24 patients with essential thrombocythemia (ET). The model reproduced well the average time-course of sTXB₂ inhibition in healthy (accuracy = 10.4%), the reduced inhibition of sTXB₂ observed in ET, and the effect of different dosing regimens. In conclusion, the in silico model accurately describes COX-1 inactivation by low-dose aspirin in MK and platelets in different clinical settings, and might help personalize aspirin regimens in conditions of altered megakaryopoiesis.

Aspirin for Primary Cardiovascular Risk Prevention and Beyond in Diabetes Mellitus

Daily administration of low-dose aspirin has proved to be beneficial in preventing recurrent cardiovascular events. However, the role of aspirin for primary prevention in patients with no overt cardiovascular disease is more controversial. In fact, in lower risk patients, the modest benefit in reducing serious vascular events can be offset by the increased risk of bleeding, including intracranial and gastrointestinal hemorrhage. Diabetes mellitus has been associated with a substantially increased risk of both first and recurrent atherothrombotic events, which makes aspirin therapy of potential value in these subjects. Moving from general aspects of aspirin pharmacology and specific issues in diabetes mellitus, this article reviews the literature on the topic of aspirin for primary prevention in general, and in subjects with diabetes mellitus in particular, to culminate with arguments pro and con and a practical risk-based algorithm for aspirin initiation in daily practice.

Clinical Update: Cardiovascular Disease in Diabetes Mellitus: Atherosclerotic Cardiovascular Disease and Heart Failure in Type 2 Diabetes Mellitus - Mechanisms, Management, and Clinical Considerations

Cardiovascular disease remains the principal cause of death and disability among patients with diabetes mellitus. Diabetes mellitus exacerbates mechanisms underlying atherosclerosis and heart failure. Unfortunately, these mechanisms are not adequately modulated by therapeutic strategies focusing solely on optimal glycemic control with currently available drugs or approaches. In the setting of multifactorial risk reduction with statins and other lipid-lowering agents, antihypertensive therapies, and antihyperglycemic treatment strategies, cardiovascular complication rates are falling, yet remain higher for patients with diabetes mellitus than for those without. This review considers the mechanisms, history, controversies, new pharmacological agents, and recent evidence for current guidelines for cardiovascular management in the patient with diabetes mellitus to support evidence-based care in the patient with diabetes mellitus and heart disease outside of the acute care setting.

Celecoxib interferes to a limited extent with aspirin-mediated inhibition of platelets aggregation

AIMS

The aim of the study was to analyze the interaction between celecoxib and low dose aspirin for COX-1 binding and its consequences on the aspirin-mediated antiplatelet effects.

METHODS

We investigated ex vivo the interaction between celecoxib and aspirin for COX-1 binding and measured the resulting antiplatelet effects. We applied mechanism-based pharmacokinetic-pharmacodynamic (PKPD) modelling to analyze these data and to predict in vivo platelet aggregation for different doses and administration schedules of aspirin and celecoxib.

RESULTS

The predictions of the PK-PD model were consistent with results from previous studies that investigated interaction between aspirin and celecoxib. The modelling results indicate that celecoxib can attenuate to a limited extent the in vivo antiplatelet effects of low dose aspirin. The extent of this interaction can be substantial (up to 15% increase in platelet aggregation by 200 mg day(-1) celecoxib when combined with low dose aspirin) during the first days of aspirin administration in patients who are already treated with celecoxib, and it cannot be prevented by separate administration of the interacting drugs.

CONCLUSIONS

At the recommended therapeutic doses, celecoxib can attenuate to a limited extent the in vivo antiplatelet effects of low dose aspirin. Patients receiving a combination of low dose aspirin and the recommended doses of celecoxib were not identified to have increased risk of cardiovascular and cerebrovascular events due to competition between these drugs for COX-1 binding. Interaction between low dose aspirin and other COX-2 inhibitors and its clinical consequences requires further investigation.

Aspirin in the prevention of cardiovascular events in patients with diabetes

Diabetes imparts a substantial increased risk for cardiovascular disease-related mortality and morbidity. Because of this, current medical guidelines recommend prophylactic treatment with once-daily, low-dose aspirin (acetylsalicylic acid) for primary and secondary prevention of cardiovascular (CV) events in high-risk patients. However, only modest reductions in CV events and mortality have been observed with once-daily aspirin treatment in patients with diabetes, including patients with a previous CV event, perhaps because of disparity between aspirin pharmacokinetics and diabetes-related platelet abnormalities. Once-daily aspirin irreversibly inactivates platelets for only a short duration (acetylsalicylic acid half-life, approximately 15-20 minutes), after which time newly generated, active platelets enter the circulation and weaken aspirin's effect. Platelets from patients with diabetes are more reactive and are turned over more rapidly than platelets from normal individuals; the short inhibitory window provided by once-daily aspirin may therefore be insufficient to provide 24-h protection against CV events. Alternative conventional aspirin regimens (e.g. higher daily dose, twice-daily dosing, combination with clopidogrel) and newer formulations (e.g. 24-h, extended-release) have been proposed to overcome the apparent limited efficacy of conventional aspirin in patients with diabetes; however, tolerability concerns and limited clinical efficacy data need to be taken into account when considering the use of such regimens.