Platelet Inhibition with Ticagrelor versus Clopidogrel in Diabetic Patients after Percutaneous Coronary Intervention for Chronic Coronary Syndromes

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.

Antithrombotic Treatment in Coronary Artery Disease

Coronary artery disease exhibits growing mortality and morbidity worldwide despite the advances in pharmacotherapy and coronary intervention. Coronary artery disease is classified in the acute coronary syndromes and chronic coronary syndromes according to the most recent guidelines of the European Society of Cardiology. Antithrombotic treatment is the cornerstone of therapy in coronary artery disease due to the involvement of atherothrombosis in the pathophysiology of the disease. Administration of antiplatelet agents, anticoagulants and fibrinolytics reduce ischemic risk, which is amplified early post-acute coronary syndromes or post percutaneous coronary intervention; though, antithrombotic treatment increases the risk for bleeding. The balance between ischemic and bleeding risk is difficult to achieve and is affected by patient characteristics, procedural parameters, concomitant medications and pharmacologic characteristics of the antithrombotic agents. Several pharmacological strategies have been evaluated in patients with coronary artery disease, such as the effectiveness and safety of antithrombotic agents, optimal dual antiplatelet treatment schemes and duration, aspirin de-escalation strategies of dual antiplatelet regimens, dual inhibition pathway strategies as well as triple antithrombotic therapy. Future studies are needed in order to investigate the gaps in our knowledge, including special populations.

Monitoring of Antiplatelet Therapy

In the late 1990s, the antithrombotic antiplatelet agent, clopidogrel, a P2Y12 inhibitor, was introduced. Around the same time, there was an increase in a number of new methods to measure platelet function (e.g., PFA-100 in 1995), and this has continued. It became evident that not all patients responded to clopidogrel in the same way and that some patients had a relative "resistance" to therapy, termed "high on-treatment platelet reactivity." This then led to some publications to advocate platelet function testing being used for patients on antiplatelet therapy. Platelet function testing was also suggested for use in patients awaiting cardiac surgery after stopping their antiplatelet therapy as a way of balancing thrombotic risk pre-surgery and bleeding risk perioperatively. This chapter will discuss some of the commonly used platelet function tests used in these settings, particularly those that are sometimes referred to as point-of-care tests or that require minimal laboratory sample manipulation. The latest guidance and recommendations for platelet function testing will be discussed following several clinical trials looking at the usefulness of platelet function testing in these clinical settings.

High platelet reactivity is a predictor of left ventricular remodelling in patients with acute myocardial infarction

AIMS

Acute myocardial infarction (AMI) is associated with left ventricular remodelling (LVR), which leads to progressive heart failure. Platelets play a pivotal role in promoting systemic and cardiac inflammatory responses during the complex process of myocardial wound healing or repair following AMI. This study aimed to investigate the impact of platelet reactivity immediately after primary percutaneous coronary intervention (PCI) on LVR in AMI patients with ST-segment (STEMI) and non-ST-segment elevation (NSTEMI).

METHODS AND RESULTS

This prospective, single-centre, observational study included 182 patients with AMI who underwent primary PCI (107 patient with STEMI and 75 patients with NSTEMI). Patients were administered a loading dose of aspirin plus prasugrel before the procedure, and platelet reactivity was assessed using the VerifyNow P2Y12 assay immediately after PCI. Echocardiography was performed before discharge and during the chronic phase (8 ± 3 months after discharge). LVR was defined as a relative ≥20% increase in left ventricular end-diastolic volume index (LVEDVI). LVR in chronic phase was found in 34 patients (18.7%) whose platelet reactivity was significantly higher than those without LVR (259.6 ± 61.5 and 213.1 ± 74.8 P2Y12 reaction units [PRU]; P = 0.001). The occurrence of LVR did not differ between patients with STEMI and patients with NSTEMI (21.5% and 14.7%; P = 0.33). The optimal cut-off value of platelet reactivity for discriminating LVR was ≥245 PRU. LVEDVI significantly decreased at chronic phase in patients without high platelet reactivity (<245 PRU) (from 49.2 ± 13.5 to 45.4 ± 15.8 mL/m² ; P = 0.02), but not in patients with high platelet reactivity (≥d245 PRU) (P = 0.06). Multivariate logistic analysis showed that high platelet reactivity was an independent predictor of LVR after adjusting for LVEDVI before discharge (odds ratio, 4.13; 95% confidence interval, 1.85-9.79).

CONCLUSIONS

High platelet reactivity measured immediately after PCI was a predictor of LVR in patients with AMI during the chronic phase. The role of antiplatelet therapy on inflammation in the myocardium is a promising area for further research.

Diabetes and Outcomes Following Personalized Antiplatelet Therapy in Coronary Artery Disease Patients Who Have Undergone PCI

CONTEXT

A personalized antiplatelet therapy guided by a novel platelet function testing (PFT), PL-12, is considered an optimized treatment strategy in stable coronary artery disease (CAD) patients undergoing percutaneous coronary intervention (PCI). However, the safety and efficacy of any dual-antiplatelet therapy (DAPT) strategy may differ in relation to diabetes status.

OBJECTIVE

The aim of this study was to compare the outcomes of PFT-guided personalized DAPT in stable CAD patients with and without diabetes mellitus.

METHODS

The PATH-PCI trial randomly assigned 2285 stable CAD patients to either personalized antiplatelet therapy or standard antiplatelet treatment. We investigated the association and interaction of diabetes on clinical outcomes across 2 treatment groups.

RESULTS

We did not find a significant difference between the personalized group and the standard group in net adverse clinical events in either diabetes patients (10.3% vs 13.4%, P = .224) or in the nondiabetic group (3.1% vs 5.0%, P = .064). In diabetes patients (n = 646, 28.3%), the overall ischemic event rates were significantly low (6.8% vs 11.3%, HR = 0.586, 95% CI, 0.344-0.999, P = .049) and the bleeding event rates did not differ between the 2 groups (3.5% vs 3.3%, HR = 1.066, 95% CI, 0.462-2.458, P = .882). Similarly, in nondiabetic patients, the overall ischemic event rates were significantly low (1.8% vs 4.2%, HR = 0.428, 95% CI, 0.233-0.758, P = .006) and the bleeding event rates did not differ between the 2 groups (1.6% vs 0.9%, HR = 1.802, 95% CI: 0.719-4.516, P = .209).

CONCLUSION

The present study suggests that personalized antiplatelet therapy according to PFT can reduce ischemic events but not increase bleedings in stable CAD patients with or without diabetes who have undergone PCI.

Clopidogrel versus ticagrelor in the treatment of Chinese patients undergoing percutaneous coronary intervention: effects on platelet function assessed by platelet function tests and mean platelet volume

Background

Knowledge on the pharmacodynamic effects of antiplatelet drugs including clopidogrel and ticagrelor on Asian patients is scarce. We aim to evaluate the effects of the two drugs on platelet reactivity in the treatment of Chinese patients who underwent percutaneous coronary intervention (PCI), using two platelet function tests (PFT). Meanwhile, the relationship between mean platelet volume (MPV), a routine index of platelet size, and high on-treatment platelet reactivity (HPR) is also investigated.

Methods

Patients receiving dual antiplatelet therapy (DAPT) were scheduled for the assessment of platelet reactivity at 2–3 days after PCI. Two PFTs, light transmission aggregometry (LTA) and vasodilator-stimulated phosphoprotein (VASP)-FCM assay, were applied in the evaluation of platelet reactivity. The MPV was measured simultaneously with EDTA plasma using a Sysmex XN 2000 automated hematology analyzer.

Results

The final study population included the aspirin + clopidogrel group (n = 46) and the aspirin + ticagrelor group (n = 66). In the aspirin + ticagrelor group, the maximal light transmittance (LT) changes in response to 5 μM ADP assessed by LTA was obviously lower than that in the aspirin + clopidogrel group (P <  0.001). The platelet reactivity index (PRI) level in the VASP test was also markedly lower in the group given aspirin and ticagrelor (P <  0.001). There was a significant difference in HPR between the two groups. MPV showed a potent ability to predict the presence of HPR at VASP assay (AUC = 0.788, 95% CI: 0.701–0.875, P <  0.001) in receiver-operating characteristic curve analysis.

Conclusions

Compared with clopidogrel, ticagrelor has dramatically greater antiplatelet effect, with a superiority in suppressing platelet function and a lower HPR rate. In addition, there existed a significant independent association between MPV and high prevalence of HPR in the VASP assay.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12959-021-00350-2.

A Case of Ticagrelor Resistance

Ticagrelor is a directly acting cyclopentyltriazolo-pyrimidine which does not require conversion into an active metabolite. It inhibits the P2Y₁₂ receptors on platelets reversibly. Unlike clopidogrel and prasugrel, resistance to ticagrelor is rarely reported. Various mechanisms have been proposed for this resistance. The case of a 62-year-old man with diabetes who had undergone index percutaneous coronary intervention (PCI) 22 days previously is described. The patient presented to us with stent thrombosis. His primary PCI was successfully carried out with a drug-eluting stent. He showed resistance to ticagrelor on thromboelastography platelet mapping. He responded well to prasugrel (another P2Y₁₂ inhibitor) in combination with aspirin.

LEARNING POINTS

Ticagrelor is a pro-drug and directly inhibits P2Y₁₂ receptors.This makes ticagrelor less susceptible to drug-drug interactions or pharmacogenetic influences.Thromboelastography platelet mapping measures the physical properties of clot formation and can reveals platelet resistance to various P2Y₁₂ inhibitors, including ticagrelor.