The paradox of clopidogrel use in patients with acute coronary syndromes and diabetes: insight from the Diabetes and Acute Coronary Syndrome Registry

Balancing Benefits and Risks of Oral Antiplatelet Strategies in patients With Coronary Artery Diseases: An Evolving Issue

Identifying the most appropriate antiplatelet therapy for each patient to prevent ischemic events while minimizing the risk of bleeding is an integral part of the short- and long-term management of patients with coronary artery disease (CAD). This review aims to summarize the available evidence on the contemporary use of P2Y12 inhibitors in CAD patients, focusing on strategies aimed at providing adequate ischemic protection while preventing bleeding risk through dual antiplatelet therapy (DAPT) modulation. Randomized trials and observational studies have been reviewed to determine the most appropriate antiplatelet treatment for CAD patients with different risk profiles. Both ischemic and bleeding events have a significant prognostic impact and should be carefully considered in clinical decision-making. Current guidelines recommend the use of third-generation PY2Y12 inhibitors (prasugrel or ticagrelor) over clopidogrel, as a part of DAPT, in patients with acute coronary syndrome (ACS) undergoing percutaneous coronary intervention. Newer P2Y12 inhibitors have a more rapid onset of action and less interindividual variability in platelet inhibition than clopidogrel but are associated with an increased risk of bleeding that may limit their benefit. Importantly, the anti-ischemic benefit of ticagrelor and prasugrel is mainly observed in the first weeks after ACS, whereas clopidogrel seems to provide the best balance between ischemic protection and bleeding as long-term maintenance therapy. These concepts support DAPT modulation after the acute phase, by de-escalating from full-dose to low-dose newer P2Y12 inhibitors, by switching to clopidogrel, or by early withdrawing aspirin to maximize both the efficacy and safety of antiplatelet therapy in patients with CAD.

Clinical implications of diabetes mellitus in patients with acute coronary syndrome: Prognostic role and use of new P2Y12 receptor inhibitors

AIMS

We investigated the impact of diabetes mellitus (DM) in acute coronary syndrome (ACS) patients, and the 2-year prognosis based on antiplatelet therapy.

METHODS

This is a prospective and multicenter registry including hospitalized ACS patients. Clinical management and antiplatelet therapy at discharge were recorded. Bleeding events, all-cause mortality and major adverse cardiovascular events (MACEs) were recorded during 2-years and compared according to DM and the P2Y₁₂ receptor inhibitor.

RESULTS

From 1717 ACS patients, 653 (38%) had DM. Diabetic patients were older, more commonly females, with higher prevalence of comorbidities and more conservative management. After excluding antiplatelet monotherapy or oral anticoagulation, clopidogrel was prescribed in 59.6% of DM patients. Cox regression analysis showed that DM was an independent risk factor for MACE (aHR 1.39, 95% CI 1.05-1.83). The use of clopidogrel instead of ticagrelor/prasugrel was also independently associated with MACE (aHR 1.71, 95% CI 1.11-2.63), and all-cause mortality (aHR 2.47, 95% CI 1.23-4.96) in diabetic patients (log-rank p-values < 0.001).

CONCLUSIONS

In ACS patients, DM was associated with higher risk of MACE. In such patients, the use of ticagrelor/prasugrel reduced MACE and mortality compared to clopidogrel. Novel P2Y₁₂ receptor inhibitors might be used as the first therapeutic choice in these high-risk patients.

Efficacy and Safety of Ticagrelor in Diabetes Patients Undergoing Percutaneous Coronary Intervention: A Meta-Analysis of Randomized Controlled Trials

ABSTRACT

Dual antiplatelet treatment, consisting of aspirin and P2Y12 inhibitors, is essential for diabetes mellitus (DM) patients who have undergone percutaneous coronary intervention (PCI). This meta-analysis investigated whether ticagrelor, a novel P2Y12 inhibitor, was superior to clopidogrel and prasugrel in efficacy and safety for DM patients undergoing PCI. PubMed, the Cochrane Library and Google Scholar were searched for randomized controlled trials in which ticagrelor was administered. Eligible studies were independently scrutinized to extract data and assess the trials' quality. Statistical analysis was performed by calculating odds ratios (OR) and 95% confidence intervals (CI). A total of 8 studies consisting of 1056 patients were included. Results showed that ticagrelor reduced the major adverse cardiac events incidence compared with clopidogrel and prasugrel in the overall (OR = 0.40; 95% CI, 0.20-0.79; P = 0.008) and subgroup analyses compared with clopidogrel (OR = 0.39; 95% CI, 0.19-0.80; P = 0.01). No difference was observed in mortality rates (OR = 0.58; 95% CI, 0.23-1.45; P = 0.25), myocardial infarction (OR = 0.67; 95% CI, 0.28-1.60; P = 0.37), stroke (OR = 0.54; 95% CI, 0.10-3.01; P = 0.49), and total bleeding (OR = 1.70; 95% CI, 0.91-3.17; P = 0.10) between the ticagrelor and control groups. In DM patients undergoing PCI, ticagrelor significantly reduced major adverse cardiac events compared with clopidogrel and prasugrel in the overall and in the subgroup of clopidogrel. There was no difference regarding mortality, myocardial infarction, stroke, and bleeding. More randomized controlled trials are required to further validate these results.

Comorbidity and low use of new antiplatelets in acute coronary syndrome

INTRODUCTION

Despite the use of the new generation P2Y12 inhibitors (Ticagrelor and Prasugrel) with aspirin is the recommended therapy in acute NSTE-ACS patients, their current use in clinical practice remains quite low and might be related, among several variables, with increased comorbidity burden. We aimed to assess the prevalence of these treatments and whether their use could be associated with comorbidity.

METHOD

A multicentric prospective registry was conducted at 8 Cardiac Intensive Care Units (October 2017-April 2018) in patients admitted with non ST elevation myocardial infarction. Antithrombotic treatment was recorded and the comorbidity risk was assessed using the Charlson Comorbidity Index. We created a multivariate model to identify the independent predictors of the use of new inhibitors of P2Y12.

RESULTS

A total of 629 patients were included, median age 67 years, 23.2% women, 359 patients (57.1%) treated with clopidogrel and 40.6% with new P2Y12 inhibitors: ticagrelor (228 patients, 36.2%) and prasugrel (30 patients, 4.8%). Among the patients with very high comorbidity (Charlson Score > 6) clopidogrel was the drug of choice (82.6%), meanwhile in patients with low comorbility (Charlson Score 0-1) was the ticagrelor or prasugrel (63.6%). Independent predictors of the use of ticagrelor or prasugrel were a low Charlson Comorbidity Index, a low CRUSADE score and the absence of prior bleeding.

CONCLUSION

Antiplatelet treatment with Ticagrelor or Pasugrel was low in patients admitted with NSTE-ACS. Comorbidity calculated with Charlson Comorbidity Index was a powerful predictor of the use of new generation P2Y12 inhibitors in this population.

The Role of Clopidogrel in 2020: A Reappraisal

Antiplatelet therapy is the mainstay of treatment and secondary prevention of cardiovascular disease (CVD), including acute coronary syndrome (ACS), transient ischemic attack (TIA) or minor stroke, and peripheral artery disease (PAD). The P2Y₁₂ inhibitors, of which clopidogrel was the first, play an integral role in antiplatelet therapy and therefore in the treatment and secondary prevention of CVD. This review discusses the available evidence concerning antiplatelet therapy in patients with CVD, with a focus on the role of clopidogrel. In combination with aspirin, clopidogrel is often used as part of dual antiplatelet therapy (DAPT) for the secondary prevention of ACS. Although newer, more potent P2Y₁₂ inhibitors (prasugrel and ticagrelor) show a greater reduction in ischemic risk compared with clopidogrel in randomized trials of ACS patients, these newer P2Y₁₂ inhibitors are often associated with an increased risk of bleeding. Deescalation of DAPT by switching from prasugrel or ticagrelor to clopidogrel may be required in some patients with ACS. Furthermore, real-world studies of ACS patients have not confirmed the benefits of the newer P2Y₁₂ inhibitors over clopidogrel. In patients with very high-risk TIA or stroke, short-term DAPT with clopidogrel plus aspirin for 21-28 days, followed by clopidogrel monotherapy for up to 90 days, is recommended. Clopidogrel monotherapy may also be used in patients with symptomatic PAD. In conclusion, there is strong evidence supporting the use of clopidogrel antiplatelet therapy in several clinical settings, which emphasizes the importance of this medication in clinical practice.

Factors associated with platelet reactivity during dual antiplatelet therapy in patients with diabetes after acute coronary syndrome

Antiplatelet drugs are prescribed without considering the diabetic status of the patient. The objective of the current investigation was to determine the impact of clinical factors, CYP4F2 enzyme and 20-hydroxyeicosatetraenoic acid (20-HETE) concentrations on high on-treatment platelet reactivity in patients with diabetes treated with antiplatelet drugs following acute coronary syndromes. A total of 667 patients were included in the study. Dual antiplatelet drug loading dosages with aspirin (300 mg) and ticagrelor (180 mg) or clopidogrel (600 mg) were prescribed to all the studied patients. Testing of platelet aggregation was performed the day after loading antiplatelet drug dosages. Platelet aggregation test was done according to the classical Born method. Multivariate binary regression analysis demonstrated that insulin use and higher 20-HETE concentration increased the odds of high on-treatment platelet reactivity during the initiation of antiplatelet drug therapy (OR: 3.968, 95% CI: 1.478-10.656, p = 0.006 and OR: 1.139, 95% CI: 1.073-1.210, respectively, p < 0.001). Ticagrelor use decreased the odds of developing high on-treatment platelet reactivity (OR: 0.238, 95% CI: 0.097-0.585, p = 0.002). Data from this study revealed that high on-treatment platelet reactivity during dual antiplatelet therapy in patients with diabetes may depend on such factors as insulin prescription and 20-HETE concentration.

Impact of aging on platelet reactivity in diabetic patients receiving dual antiplatelet therapy

Advanced age and diabetes represent summative conditions in the determination of cardiovascular risk, and especially for the management of dual antiplatelet therapy (DAPT), often requiring balancing between bleeding and thrombotic complications. However, few studies have so far evaluated the impact of age on platelet reactivity and suboptimal platelet inhibition (high-on treatment platelet reactivity-HRPR) on DAPT among diabetic patients, that was, therefore the aim of the present study. In diabetic patients treated with DAPT (ASA + clopidogrel or ticagrelor) platelet reactivity was assessed at 30-90 days post-discharge for an acute coronary syndrome or elective PCI. Aggregation was assessed by multiple-electrode aggregometry. HRPR was defined for values above the lower limit of normality (in non-treated patients). Elderly patients were considered ≥ 75 years of age. We included 462 patients, among them 149 (32.2%) were ≥ 75 years. Elderly patients were more often females (p = 0.006), with lower body size (p = 0.04), acute coronary syndrome at presentation and renal failure (p < 0.001), non-smokers (p = 0.002), in therapy with insulin (p = 0.02) and diuretics (p < 0.001) and lower rate of betablockers (p = 0.02). Age directly related with C reactive protein (p = 0.01), creatinine levels and inversely with hemoglobin (p < 0.001) and triglycerides (p = 0.003). No association was found at linear regression analysis for platelet reactivity and age with different activating stimuli, but for ASPI test (r = 0.12; p = 0.03). No significant difference in HAPR was found in elderly patients (2.4 vs. 3.2%, p = 0.76, OR[95% CI] = 0.45[0.1-2.11], p = 0.31). HRPR for ADP antagonists was similarly not affected by age (30.1% vs. 35.7%, p = 0.28, adjusted OR[95% CI] = 0.78[0.47-1.29], p = 0.33). Comparable results were obtained when considering separately the DAPT strategies with clopidogrel or ticagrelor, or when adjusting our results according to propensity score values. Among diabetic patients receiving dual antiplatelet therapy for an acute coronary syndrome or elective percutaneous coronary intervention, age does not affect platelet reactivity or the rate of high-on treatment platelet reactivity. Similar results were obtained for ASA and clopidogrel or ticagrelor.

Vitamin D levels and platelet reactivity in diabetic patients receiving dual antiplatelet therapy

BACKGROUND

Hypovitaminosis D represents an emerging cardiovascular risk factor, and especially among higher-risk subsets of patients, such as in those with diabetes mellitus. The anti-inflammatory and anti-thrombotic properties of vitamin D, in fact, could be even more beneficial among diabetics, where platelet hyperreactivity and suboptimal response to antiplatelet drugs has been associated with poorer outcomes. However, no study has so far evaluated the impact of vitamin D levels on platelet reactivity and high-on treatment platelet reactivity (HRPR) among diabetic patients receiving dial antiplatelet therapy (DAPT).

METHODS

Our population is represented by a consecutive cohort ofdiabetic patients treated with DAPT (ASA + clopidogrel or ticagrelor or dose-adjusted prasugrel) for an acute coronary syndrome or elective PCI, undergoing platelet reactivity assessment at 30-90 days post-discharge. Aggregation was assessed by multiple-electrode aggregometry. HRPR was defined for values above the lower limit of normality (in non-treated patients).

RESULTS

We included 440 patients, that were divided according to quartiles values of vitamin D (< 9.4; 9.4-15.59; 15.6-21.64; ≥ 21.65 ng/ml). Among them, 31 were excluded as chronically treated with vitamin D supplementation. Lower vitamin D quartiles were associated with more advanced age (p = 0.01), female gender (p = 0.04), renal failure (p = 0.005), history of previous MI (p = 0.01), CABG and use of diuretics (p = 0.003), severe coronary disease (p = 0.002), but lower ejection fraction (p = 0.001), treatment with statins (p = 0.04) and new ADP-antagonists (p = 0.002). Vitamin D levels related with higher HbA1c (p = 0.001), cholesterol (p = 0.02) and creatinine (p = 0.004) and lower hemoglobin (p = 0.004). The prevalence of HRPR with ASA was low and not related to vitamin D quartiles (3.4% vs 2.7% vs 1.8% vs 2.1%, p = 0.44; adjusted OR[95%CI] = 1.16[0.60-2.26], p = 0.67). The prevalence of HRPR for ADP antagonists was associated to hypovitaminosis D (40.2% vs 29.1% vs 29.4% vs 25.5%, p = 0.03; (adjusted OR[95%CI] = 1.76[1.04-2.98], p = 0.036for I vs II-IV quartile). The impact of vitamin D quartiles, was significant only in patients on new ADP antagonists (n = 225, of whom 81 on prasugrel 5 mg; p = 0.03; adjusted OR[95%CI] = 3.12[1.34-7.49], p = 0.009) but not with clopidogrel (p = 0.85, adjusted OR[95%CI] = 1.05[0.49-2.24], p = 0.89).

CONCLUSIONS

Among diabetic patients receiving dual antiplatelet therapy for an acute coronary syndrome or elective percutaneous coronary intervention, severe vitamin D deficiency is associated with a higher ADP-mediated platelet reactivity and rate of HRPR, and especially for new ADP-antagonists over clopidogrel.