Ticagrelor in the prevention of coronary and non-coronary atherothrombotic events: A comprehensive meta-analysis of 10 randomized trials

Ticagrelor for the primary prevention of stroke in patients with coronary artery disease: a systematic review and meta-analysis of randomized controlled trials

Coronary artery disease (CAD) patients had a higher risk of first-ever stroke than general population even when they were on antiplatelet treatment. It was unknown whether more potent antiplatelet inhibitor ticagrelor which also provided adenosine-mediated protection would improve the primary stroke prevention for CAD. PubMed, Embase, Web of Science and CERNTRAL were searched for randomized clinical trials (RCTs) comparing efficacy and safety outcomes of over 30-day use of ticagrelor versus other antiplatelet drugs or placebo in patients with acute or chronic coronary syndrome. RCTs involving patients with any stroke history were excluded. Based on 5 RCTs with 45,843 patients, ticagrelor-involving regimens significantly reduced first-ever strokes (risk ratio [RR] 0.81; 95% confidential interval [CI] 0.71-0.94; I² = 0%) in comparison to other antiplatelet regimens in CAD, where the benefits in reducing ischemic strokes (IS) (RR 0.80; 95% CI 0.68-0.94; I² = 0%) was not canceled out by the increase of intracranial hemorrhage (ICH) (RR 1.41; 95% CI 1.05-1.89; I² = 0%). According to results of subgroup analyses, the protective effects of ticagrelor on first-ever stroke were more significant with treatment duration of more than 1 year, dosage of 60 mg twice daily, and in clinical settings of chronic coronary syndrome. In conclusion, available evidence from aggregate data supported a modest advantage of ticagrelor-involving regimens for the primary stroke prevention in CAD compared with other antiplatelet regimens after the trade-off between reducing IS and inducing ICH, where more benefits might be expected from long-term and low-dose use of ticagrelor among patients with chronic coronary syndrome. Further collaborative meta-analysis of individual participant data from well-designed and statistically-powered trials would be needed to generate high quality evidence on this issue.

Ticagrelor Use in Stroke Patients: Past, Present, and Future

Antiplatelet medications are the mainstay for secondary stroke treatment. Aspirin, clopidogrel, and aspirin-dipyridamole are commonly used antiplatelet medications. Other antiplatelet medications such as ticagrelor and prasugrel have been majorly used in cardiovascular or neuro-interventional specialties. Recent studies have paved a way to their use in secondary stroke prevention. In this review, we have briefly discussed the pharmacology of ticagrelor, published literature in cardiology and stroke trials, use of ticagrelor among patients with ischemic strokes, and compared its efficacy, limitations and side-effects with other antiplatelet medications.

Prolonged antithrombotic therapy in patients after acute coronary syndrome: A critical appraisal of current European Society of Cardiology guidelines

The increased risk of non-cardiovascular death in patients receiving clopidogrel or prasugrel in comparison with the placebo group in the Dual Antiplatelet Therapy (DAPT) trial in contrast to the decreased risk of cardiovascular death and all-cause death seen in patients treated with low-dose ticagrelor in the EU label population of the PEGASUS-TIMI 54 trial, resulted in inclusion in the 2020 ESC NSTE-ACS guidelines the recommendation for use of clopidogrel or prasugrel only if the patient is not eligible for treatment with ticagrelor. The prevalence of the primary outcome composed of cardiovascular death, stroke, or myocardial infarction was lower in the low-dose rivaroxaban and acetylsalicylic acid (ASA) group than in the ASA-alone group in the COMPASS trial. Moreover, all-cause mortality and cardiovascular mortality rates were lower in the rivaroxaban-plus-ASA group. Comparison of the PEGASUS-TIMI 54 and COMPASS trial patient characteristics clearly shows that each of these treatment strategies should be addressed at different groups of patients. A greater benefit in post-acute coronary syndrome (ACS) patients with a high risk of ischemic events and without high bleeding risk may be expected with ASA and ticagrelor 60 mg b.i.d. when the therapy is continued without interruption or with short interruption only after ACS. On the other hand, ASA and rivaroxaban 2.5 mg b.i.d. seems to be a better option when indications for dual antithrombotic therapy (DATT) appear after a longer time from ACS (more than 2 years) and/or from cessation of DAPT (more than 1 year) and in patients with multiple vascular bed atherosclerosis. Thus, both options of DATTs complement each other rather than compete, as can be presumed from the recommendations. However, a direct comparison between these strategies should be tested in future clinical trials.

Impact of the rs73598374 polymorphism of the adenosine deaminase gene on platelet reactivity and long-term outcomes among patients with acute coronary syndrome treated with ticagrelor

BACKGROUND

The positive interaction of ticagrelor with the metabolism of adenosine has been claimed for the large antithrombotic and antiischemic benefits of this antiplatelet agent in acute coronary syndromes (ACS). Adenosine catabolism is regulated by the activity of the adenosine deaminase enzyme (ADA), for which several polymorphisms have been identified. Therefore, the aim of our study was to explore the impact of the rs73598374 polymorphism of ADA gene on platelet reactivity in ACS patients treated with ticagrelor.

METHODS

We included consecutive patients receiving ASA and ticagrelor after an ACS and coronary intervention. Platelet reactivity was evaluated by impedance aggregometry at 30-90 days post-discharge. The genetic analysis was carried out by PCR and RFLP. Clinical endpoints were mortality, cardiovascular death, recurrent myocardial infarction or coronary revascularization at the maximum available follow-up.

RESULTS

Our population is represented by 464 patients, of whom 33.4% were A-heterozygotes and 6 homozygotes. A-allele carriers showed a greater prevalence of renal failure (p = 0.02) and a lower rate of previous coronary artery bypass graft (p = 0.03) and statin treatment (p = 0.02). No differences in the mean values of platelet reactivity or HRPR on ticagrelor were found according to the ADA genotype (11.3%vs13.9%, p = 0.45; adjusted OR[95% CI] = 1.17[0.64-2.14], p = 0.61). At follow up, patients carrying the A-allele showed a non-significantly lower incidence of ACS and repeated unplanned revascularization, although with no effect on mortality.

CONCLUSIONS

In the present study the rs73598374 polymorphism of the ADA gene did not affect platelet reactivity or the long-term prognosis in patients with ACS receiving dual antiplatelet therapy with ASA and ticagrelor.

Insights from Experiences on Antiplatelet Drugs in Stroke Prevention: A Review

Reduction of hazard risk of cerebral ischemic event (stroke, transient ischemic attack (TIA)) represents the hard point to be achieved from primary or secondary preventive strategy in the best clinical practice. However, results from clinical trials, recommendations, guidelines, systematic review, expert opinions, and meta-analysis debated on the optimal pharmacotherapy to achieve the objective. Aspirin and a number of antiplatelet agents, alone or in combination, have been considered from large trials focused on stroke prevention. The present review summarizes, discusses results from trials, and focuses on the benefits or disadvantages originating from antiplatelet drugs. Sections of the review were organized to show both benefits or consequences from antiplatelet pharmacotherapy. Conclusively, this review provides a potential synopsis on the most appropriate therapeutic approach for stroke prevention in clinical practice.

Higher neutrophil-to-lymphocyte ratio (NLR) increases the risk of suboptimal platelet inhibition and major cardiovascular ischemic events among ACS patients receiving dual antiplatelet therapy with ticagrelor

BACKGROUND

Neutrophil to lymphocyte ratio (NLR) has emerged as a useful and easy-to-assess prognostic tool and biomarker of cardiovascular risk. However, few studies have evaluated its role on platelet inhibition among patients on dual antiplatelet therapy (DAPT), and especially in the settings of acute coronary syndromes (ACS). We aimed at assessing the impact of NLR on platelet reactivity and the risk of major ischemic events at long-term follow-up among ACS patients on DAPT with ticagrelor.

METHODS

Patients on dual antiplatelet therapy with ASA + ticagrelor (90 mg/twice a day) after percutaneous coronary revascularization for ACS were scheduled for platelet function assessment 30-90 days post-discharge. Aggregation tests were performed by Multiple Electrode Aggregometry (MEA). Suboptimal platelet inhibition (HRPR-high residual platelet reactivity was defined if above the lower limit of normality (417 AU*min). The primary study endpoint was defined as the occurrence of major cardiovascular events (a composite of cardiovascular death, recurrent acute coronary syndrome, target vessel revascularization) at longest available follow-up.

RESULTS

We included 397 patients, that were divided according to NLR tertiles. Patients with higher NLR were older (p < .001), less frequently smokers (p = .03), with higher rates of renal failure (p = .001), previous bypass surgery (p = .05) and use of statins (p = .03) and diuretics (p = .01). Higher white blood cells count and C-reactive protein (p < .001) and lower haemoglobin (p = .001) were associated with NLR. Mean platelet reactivity and the prevalence of high platelet reactivity (HRPR) on ticagrelor were significantly associated to higher NLR tertiles values (7% vs 12% vs 14.3%, p = .04), with a significant relationship between NLR and platelet reactivity being confirmed for all the different activating stimuli. At a mean follow-up of 939 ± 581.4 days, 21.2% of the patients experienced the primary composite endpoint, with a trend for a higher risk of events across NLR tertiles (15.4% vs 24.2% vs 24.4%, p = .09), that became statistically significant after correction for baseline confounders (adjusted HR[95%CI] = 1.13[1.008-1.26], p = .036). Moreover, NLR was significantly associated to overall mortality and recurrent ACS (adjusted p = .008, p = .06 and p = .02 respectively).

CONCLUSIONS

In the present study we found that among ACS patients treated with ASA and ticagrelor after PCI, suboptimal platelet inhibition despite DAPT was significantly increased for higher values of Neutrophil-to-Lymphocyte Ratio. Moreover, mortality and the risk of recurrent major ischemic events at long-term were associated to NLR.

Homocysteine levels and platelet reactivity in coronary artery disease patients treated with ticagrelor

BACKGROUND AND AIM

Recurrent atherothrombotic events have been reported in certain higher risk subsets of patients even with ticagrelor, a potent first-line antiplatelet agent for the management of patients with acute coronary syndrome (ACS). Hyperhomocysteinemia is a known determinant of platelet function abnormalities. Therefore, the aim of our study was to evaluate the impact of homocysteine (Hcy) levels on platelet reactivity in patients receiving Ticagrelor.

METHODS AND RESULTS

Patients with ACS undergoing percutaneous coronary revascularization and on dual antiplatelet therapy with ASA + Ticagrelor (90mg/twice a day) were scheduled for platelet function assessment 30-90 days post-discharge. Aggregation tests were performed by Multiple Electrode Aggregometry (MEA). Suboptimal platelet inhibition HRPR-high residual platelet reactivity was defined if above the lower limit of normality (417 AU*min). We included 432 patients, divided according to Hcy tertiles. Higher Hcy levels were associated with age, renal failure, creatinine levels and use diuretics (p < 0.001). Patients with higher Hcy levels displayed a higher platelet reactivity at COL test (p = 0.002), and ADP test (p = 0.04), with a linear relationship between Hcy and platelet aggregation after stimulation with collagen (r = 0.202, p < 0.001), thrombin receptor peptide (r = 0.104, p = 0.05) and ADP (r = 0.145, p = 0.006). However, Hcy levels did not significantly affect the rate of HRPR with Ticagrelor (9.9% vs 13.7% vs 10.7%, p = 0.89; adjusted OR [95% CI] = [0.616-1.51], p = 0.99).

CONCLUSIONS

Among patients with ACS, despite the elevated platelet reactivity associated to hyperhomocysteinemia, DAPT with ticagrelor could overcome such phenomenon, achieving an adequate platelet inhibition in the majority of the patients.