State-of-the-Art: Hypo-responsiveness to oral antiplatelet therapy in patients with type 2 diabetes mellitus

Cardiovascular Outcomes Observed with Ticagrelor versus Clopidogrel in Type 2 Diabetes Mellitus Patients with Acute Coronary Syndrome: A Meta-analysis

INTRODUCTION

Type 2 diabetes mellitus (T2DM) is often associated with macrovascular complications including cardiovascular diseases (CVDs), resulting in acute coronary syndrome (ACS). Newer potent antiplatelet agents have recently been approved for use in clinical practice. In this analysis, we aimed to systematically compare the cardiovascular outcomes observed with ticagrelor versus clopidogrel in T2DM patients with ACS.

METHODS

From August to September 2022, electronic databases were searched for publications that compared cardiovascular outcomes observed with ticagrelor versus clopidogrel in patients with T2DM. The statistical analysis was carried out using RevMan 5.4 software. A random effect statistical model was used to analyze the data. Risk ratios (RR) with 95% confidence intervals (CIs) were used to represent the data post analysis.

RESULTS

A total of 5868 participants with T2DM were included in this analysis, of which 1944 participants were assigned to the ticagrelor group and 3924 participants were assigned to the clopidogrel group. Our analysis showed that ticagrelor was associated with a significantly lower risk of major adverse cardiac events (MACEs) (RR: 0.64, 95% CI: 0.49-0.84; P = 0.001), all-cause mortality (RR: 0.65, 95% CI: 0.51-0.83; P = 0.0004), and cardiac death (RR: 0.60, 95% CI: 0.43-0.84; P = 0.003) in comparison to clopidogrel. However, the risks of repeated revascularization (RR: 1.48, 95% CI: 0.44-4.99; P = 0.53), stent thrombosis (RR: 0.70, 95% CI: 0.18-2.71; P = 0.60), reinfarction (RR: 0.85, 95% CI: 0.58-1.23; P = 0.39), and stroke (RR: 0.56, 95% CI: 0.14-2.21; P = 0.41) were similar. Ticagrelor was associated with a significantly higher risk of minor bleeding (RR: 1.53, 95% CI: 1.07-2.19; P = 0.02), whereas the risk for major bleeding (RR: 1.08, 95% CI: 0.55-2.10; P = 0.82) was not significantly different.

CONCLUSIONS

In these T2DM patients with ACS, a significantly lower risk of major adverse cardiovascular events including all-cause mortality was observed in the ticagrelor group compared with the clopidogrel group. However, T2DM patients who were assigned to ticagrelor showed a significantly higher minor bleeding risk. Larger clinical trials should be able to confirm these hypotheses.

Clopidogrel Monotherapy After 1-Month Dual Antiplatelet Therapy in Patients With Diabetes Undergoing Percutaneous Coronary Intervention

BACKGROUND

Diabetes was reported to be associated with an impaired response to clopidogrel.

OBJECTIVES

The aim of this study was to evaluate the safety and efficacy of clopidogrel monotherapy after very short dual antiplatelet therapy (DAPT) in patients with diabetes undergoing percutaneous coronary intervention (PCI).

METHODS

A subgroup analysis was conducted on the basis of diabetes in the STOPDAPT-2 (Short and Optimal Duration of Dual Antiplatelet Therapy After Everolimus-Eluting Cobalt-Chromium Stent-2) Total Cohort (N = 5,997) (STOPDAPT-2, n = 3,009; STOPDAPT-2 ACS [Short and Optimal Duration of Dual Antiplatelet Therapy After Everolimus-Eluting Cobalt-Chromium Stent-2 for the Patients With ACS], n = 2,988), which randomly compared 1-month DAPT followed by clopidogrel monotherapy with 12-month DAPT with aspirin and clopidogrel after cobalt-chromium everolimus-eluting stent implantation. The primary endpoint was a composite of cardiovascular (cardiovascular death, myocardial infarction, definite stent thrombosis, or stroke) or bleeding (TIMI [Thrombolysis In Myocardial Infarction] major or minor) endpoints at 1 year.

RESULTS

There were 2,030 patients with diabetes (33.8%) and 3967 patients without diabetes (66.2%). Regardless of diabetes, the risk of 1-month DAPT relative to 12-month DAPT was not significant for the primary endpoint (diabetes, 3.58% vs 4.12% [HR: 0.87; 95% CI: 0.56-1.37; P = 0.55]; nondiabetes, 2.46% vs 2.49% [HR: 0.99; 95% CI: 0.67-1.48; P = 0.97]; P_interaction = 0.67) and for the cardiovascular endpoint (diabetes, 3.28% vs 3.05% [HR: 1.10; 95% CI: 0.67-1.81; P = 0.70]; nondiabetes, 1.95% vs 1.43% [HR: 1.38; 95% CI: 0.85-2.25; P = 0.20]; P_interaction = 0.52), while it was lower for the bleeding endpoint (diabetes, 0.30% vs 1.50% [HR: 0.20; 95% CI: 0.06-0.68; P = 0.01]; nondiabetes, 0.61% vs 1.21% [HR: 0.51; 95% CI: 0.25-1.01; P = 0.054]; P_interaction = 0.19).

CONCLUSIONS

Clopidogrel monotherapy after 1-month DAPT compared with 12-month DAPT reduced major bleeding events without an increase in cardiovascular events regardless of diabetes, although the findings should be considered as hypothesis generating, especially in patients with acute coronary syndrome, because of the inconclusive result in the STOPDAPT-2 ACS trial. (Short and Optimal Duration of Dual Antiplatelet Therapy After Everolimus-Eluting Cobalt-Chromium Stent-2 [STOPDAPT-2], NCT02619760; Short and Optimal Duration of Dual Antiplatelet Therapy After Everolimus-Eluting Cobalt-Chromium Stent-2 for the Patients With ACS [STOPDAPT-2 ACS], NCT03462498).

Antiplatelet drugs and liver fibrosis

Liver fibrosis results from an imbalance between extracellular matrix formation and degradation. The background of liver fibrosis is chronic inflammation and subsequent microcirculation disturbance including microthrombosis. Platelets actively participate in liver fibrosis not only as a part of the clotting system but also by releasing granules containing important mediators. In fact, platelets may play a dual role in the pathophysiology of liver fibrosis as they are able to stimulate regeneration as well as aggravate the destruction of the liver. Recent studies revealed that antiplatelet therapy correlates with inhibition of liver fibrosis. However, liver impairment is associated with extensive coagulation disorders thus the safety of antiplatelet therapy is an area for detailed exploration. In this review, the role of platelets in liver fibrosis and accompanying hemostatic disorders are discussed. Additionally, results of animal and human studies on antiplatelet drugs in liver disorders and their potential therapeutic utility are presented.

Impact of Diabetes on Platelet Function in Acute Ischemic Stroke Patients Taking Dual Antiplatelet Therapy

Objectives: Diabetes mellitus (DM) is a significant risk factor for ischemic stroke and associated with platelet reactivity. We aim to evaluate the effect of DM on platelet function in acute ischemic stroke patients taking dual antiplatelet therapy (DAPT).

Methods: We consecutively included patients with acute ischemic stroke taking DAPT. Platelet function was assessed by thromboelastography and the arachidonic acid (AA) or adenosine diphosphate (ADP) induced platelet inhibition rate were used to confirmed the high-residual on-treatment platelet reactivity (HRPR) to aspirin or clopidogrel. We classified patients into DM and non-DM groups. The association between DM and platelet function was assessed and the confounding factors were adjusted by propensity score matching (PSM) analysis. The independent risk factors of HRPR were determined by multivariate logistic regression analysis.

Results: A total of 1,071 acute ischemic stroke patients, 712 in the non-DM group and 359 in the DM group, were included. Patients with DM had a significantly higher maximum amplitude (63.0 vs. 62.0 mm, P < 0.01), ADP-induced clot strength (34.6 vs. 30.3 mm, P < 0.01) and clopidogrel HRPR rate (22.6% vs. 17.3%, P = 0.038) than those without DM. Among 662 patients after PSM, the maximum amplitude (63.1 vs. 62.5 mm, P = 0.032), ADP-induced clot strength (34.6 vs. 29.3 mm, P < 0.01) and clopidogrel HRPR rate (23.0% vs. 15.7%, P = 0.018) is still higher in the DM group. DM was an independent factor of clopidogrel HRPR (OR = 1.48, 95% CI: 1.03–2.07, P < 0.05).

Conclusions: In acute ischemic stroke patients taking DAPT, DM is associated with increased platelet reactivity and higher prevalence of clopidogrel HRPR.

Impact of diabetes mellitus on outcomes of percutaneous coronary intervention in chronic total occlusions: A systematic review and meta-analysis

BACKGROUND

Patients with diabetes mellitus (DM) have a high prevalence of coronary chronic total occlusions (CTOs). We conducted a systematic review and meta-analysis to characterize outcomes after CTO percutaneous coronary intervention (PCI) in patients without or with DM.

METHODS

PubMed, EMBASE, Cochrane, and Google Scholar were queried for studies comparing non-DM vs. DM patients undergoing attempted CTO PCI. The primary outcome was all-cause mortality at longest follow-up (at least 6 months). Secondary outcomes were major adverse cardiovascular events (MACE) which is a composite endpoint including myocardial infarction, cardiac or all-cause mortality and any revascularization in patients after CTO PCI, target vessel revascularization (TVR), myocardial infarction (MI), Japanese chronic total occlusion (J-CTO) score and prevalence of multivessel (MV) CTO disease. We used a random effects model to calculate odds ratios (ORs) and 95% confidence intervals (CIs).

RESULTS

Sixteen studies, including 2 randomized control trials and 14 observational studies, met inclusion criteria. At longest follow-up, all-cause mortality (OR 0.54 [95% CI 0.37-0.80], p < 0.0001) and MACE (OR 0.82 [95% CI 0.72-0.93], p < 0.00001) were significantly lower in non-DM CTO patients. MV CTO disease was less prevalent in patients without DM (OR 0.80 [95% CI 0.69-0.93], p = 0.004). However, there were no differences in MI, TVR and J-CTO score.

CONCLUSIONS

Non-diabetics undergoing CTO PCI have lower all-cause mortality and MACE than diabetics. Future research may determine if DM control improves diabetics' CTO PCI outcomes.

Increased bleeding events with the addition of apixaban to the dual anti-platelet regimen for the treatment of patients with acute coronary syndrome: A meta-analysis

BACKGROUND

Dual anti-platelet therapy (DAPT) with aspirin and clopidogrel has been the mainstay of treatment for patients with acute coronary syndrome (ACS). However, the recurrence of thrombotic events, potential aspirin and clopidogrel hypo-responsiveness, and other limitations of DAPT have led to the development of newer oral anti-thrombotic drugs. Apixaban, a new non-vitamin K antagonist, has been approved for use. In this meta-analysis, we aimed to compare the bleeding outcomes observed with the addition of apixaban to DAPT for the treatment of patients with ACS.

METHODS

Online databases including EMBASE, Cochrane Central, http://www.ClinicalTrials.gov, MEDLINE and Web of Science were searched for English based publications comparing the use of apixaban added to DAPT for the treatment of patients with ACS. Different categories of bleeding events and cardiovascular outcomes were assessed. The analysis was carried out by the RevMan software version 5.4. Odds ratios (OR) with 95% confidence intervals (CI) were used to represent the data following analysis.

RESULTS

This research analysis consisted of 4 trials with a total number of 9010 participants. Thrombolysis in myocardial infarction (TIMI) defined major bleeding (OR: 2.45, 95% CI: 1.45-4.12; P = .0008), TIMI defined minor bleeding (OR: 3.12, 95% CI: 1.71-5.70; P = .0002), International society of thrombosis and hemostasis (ISTH) major bleeding (OR: 2.49, 95% CI: 1.80-3.45; P = .00001) and Global Use of Strategies to Open Occluded Arteries (GUSTO) defined severe bleeding (OR: 3.00, 95% CI: 1.56-5.78; P = .01) were significantly increased with the addition of apixaban to DAPT versus DAPT alone in these patients with ACS. However fatal bleeding (OR: 10.96, 95% CI: 0.61-198.3; P = .11) was not significantly different.

CONCLUSIONS

Addition of the novel oral anticoagulant apixaban to the DAPT regimen significantly increased bleeding and therefore did not show any beneficial effect in these patients with ACS. However, due to the extremely limited data, we apparently have to rely on future larger studies to confirm this hypothesis.

Antithrombotic Therapy for Atherosclerotic Cardiovascular Disease Risk Mitigation in Patients With Coronary Artery Disease and Diabetes Mellitus

Patients with diabetes mellitus (DM) are characterized by enhanced thrombotic risk attributed to multiple mechanisms including hyperreactive platelets, hypercoagulable status, and endothelial dysfunction. As such, they are more prone to atherosclerotic cardiovascular events than patients without DM, both before and after coronary artery disease (CAD) is established. In patients with DM without established CAD, primary prevention with aspirin is not routinely advocated because of its increased risk of major bleeding that largely offsets its ischemic benefit. In patients with DM with established CAD, secondary prevention with antiplatelet drugs is an asset of pharmacological strategies aimed at reducing the risk of atherosclerotic cardiovascular events and their adverse prognostic consequences. Such antithrombotic strategies include single antiplatelet therapy (eg, with aspirin or a P2Y₁₂ inhibitor), dual antiplatelet therapy (eg, aspirin combined with a P2Y₁₂ inhibitor), and dual-pathway inhibition (eg, aspirin combined with the vascular dose of the direct oral anticoagulant rivaroxaban) for patients with chronic ischemic heart disease, acute coronary syndromes, and those undergoing percutaneous coronary intervention. Because of their increased risk of thrombotic complications, patients with DM commonly achieve enhanced absolute benefit from more potent antithrombotic approaches compared with those without DM, which most often occurs at the expense of increased bleeding. Nevertheless, studies have shown that when excluding individuals at high risk for bleeding, the net clinical benefit favors the use of intensified long-term antithrombotic therapy in patients with DM and CAD. Several studies are ongoing to establish the role of novel antithrombotic strategies and drug formulations in maximizing the net benefit of antithrombotic therapy for patients with DM. The scope of this review article is to provide an overview of current and evolving antithrombotic strategies for primary and secondary prevention of atherosclerotic cardiovascular events in patients with CAD and DM.

Role of platelet-derived growth factor in type II diabetes mellitus and its complications

Type 2 diabetes mellitus is a type of metabolic disorder characterized by hyperglycaemia with multiple serious complications, such as diabetic neuropathies, diabetic nephropathy, diabetic retinopathy, and diabetic foot. Platelet-derived growth factors are growth factors that regulate cell growth and division, playing a critical role in diabetes and its harmful complications. This review focused on the cellular mechanism of platelet-derived growth factors and their receptors on diabetes development. Furthermore, we raise some proper therapeutic molecular targets for the treatment of diabetes and its complications.

Gallic Acid Improves Health-Associated Biochemical Parameters and Prevents Oxidative Damage of DNA in Type 2 Diabetes Patients: Results of a Placebo-Controlled Pilot Study

SCOPE

Oxidative imbalance plays a key role in cancer induction and cardiovascular diseases (CVD) in patients with type 2 diabetes mellitus (T2DM). The aim of this study is to find out if gallic acid (GA) prevents oxidative stress in diabetic patients. Therefore, we investigate its impact on oxidation of DNA bases and on other health-related macromolecules.

METHODS AND RESULTS

We perform an intervention study (n = 19) with GA and monitored alterations of the DNA stability in single cell gel electrophoresis (SCGE) assays in lymphocytes. Furthermore, a panel of health-related biomarkers is measured before and after consumption of GA (15 mg p^-1  d^-1 ) for 7 d. Significant reduction of oxidized purines (by 31%, p < 0.001, effect size 0.404) and pyrimidines (by 2%, p < 0.022, effect size 0.089) is observed in SCGE assays. Furthermore, the plasma concentrations of oxidized-LDL and C-reactive protein are reduced after the intervention by 24% (p = 0.014, effect size 0.384) and 39% (p < 0.001, effect size 0.686), respectively. No alterations of other biomarkers are found.

CONCLUSIONS

A small amount of GA (in the range of daily consumption in Central Europe) prevents oxidative DNA damage and reduces markers which reflect inflammation and increased risks of cancer and CVD.

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.

Induction of Diabetes Abolishes the Antithrombotic Effect of Clopidogrel in Apolipoprotein E-Deficient Mice

Patients with acute coronary syndrome with diabetes mellitus (DM) exhibit an impaired platelet inhibitory response to clopidogrel which is only partially understood. DM was induced by the administration of streptozotocin (STZ) to 9-week-old mice. The antithrombotic effects of clopidogrel (10 mg/kg/d, orally × 5 days) were determined using a FeCl ₃ -induced thrombosis model employing wild-type (WT), apolipoprotein E (apoE)-deficient, and diabetic apoE-deficient mice at 21 weeks. Antiplatelet effects were determined using flow cytometry. The antithrombotic effects of clopidogrel were similar in WT and apoE-deficient mice but were attenuated in diabetic apoE-deficient mice with the percent inhibition of thrombus area (µm ² ) by clopidogrel being 85.5% (WT mice), 75.0% (apoE-deficient mice), and 1.9% (diabetic apoE-deficient mice). The time to first occlusion and lumen stenosis also reflected a significant loss of the antithrombotic effects of clopidogrel in diabetic apoE-deficient mice. Ex vivo platelet activation, which was assessed using ADP-induced expression of activated glycoprotein IIb/IIIa, was completely inhibited by clopidogrel in these three groups of mice. In contrast, the effect of clopidogrel on the ex vivo expression of platelet P-selectin induced by protease-activated receptor 4–activating peptide was diminished in diabetic apoE-deficient mice compared with that in WT and apoE-deficient mice. These data suggest that diabetic apoE-deficient mice may serve as a useful model to better understand the impaired responses to clopidogrel in patients with DM, which may partially reflect a reduction of the effect of clopidogrel on thrombin-induced platelet activation.