A Comprehensive Review of the Pleiotropic Effects of Ticagrelor

AIMS

This review summarizes the findings of preclinical studies evaluating the pleiotropic effects of ticagrelor. These include attenuation of ischemia-reperfusion injury (IRI), inflammation, adverse cardiac remodeling, and atherosclerosis. In doing so, it aims to provide novel insights into ticagrelor's mechanisms and benefits over other P2Y12 inhibitors. It also generates viable hypotheses for the results of seminal clinical trials assessing ticagrelor use in acute and chronic coronary syndromes.

METHODS AND RESULTS

A comprehensive review of the preclinical literature demonstrates that ticagrelor protects against IRI in the setting of both an acute myocardial infarction (MI), and when MI occurs while on chronic treatment. Maintenance therapy with ticagrelor also likely mitigates adverse inflammation, cardiac remodeling, and atherosclerosis, while improving stem cell recruitment. These effects are probably mediated by ticagrelor's ability to increase local interstitial adenosine levels which activate downstream cardio-protective molecules. Attenuation and augmentation of these pleiotropic effects by high-dose aspirin and caffeine, and statins respectively may help explain variable outcomes in PLATO and subsequent randomized controlled trials (RCTs).

CONCLUSION

Most RCTs and meta-analyses have not evaluated the pleiotropic effects of ticagrelor. We need further studies comparing cardiovascular outcomes in patients treated with ticagrelor versus other P2Y12 inhibitors that are mindful of the unique pleiotropic advantages afforded by ticagrelor, as well as possible interactions with other therapies (e.g., aspirin, statins, caffeine).

Ticagrelor monotherapy after a short course of dual antiplatelet therapy with ticagrelor plus aspirin following percutaneous coronary intervention in patients with versus without diabetes mellitus: a meta-analysis of randomized trials

BACKGROUND

Cardiovascular disease (CVD) is one among the major causes of mortality all round the globe. Several anti-platelet regimens have been proposed following percutaneous coronary intervention (PCI). In this analysis, we aimed to show the adverse clinical outcomes associated with ticagrelor monotherapy after a short course of dual antiplatelet therapy (DAPT) with ticagrelor and aspirin following PCI in patients with versus without diabetes mellitus (DM).

METHODS

Electronic databases were searched by four authors from September to November 2023. Cardiovascular outcomes and bleeding events were the endpoints of this analysis. Revman 5.4 software was used to conduct this meta-analysis. Risk ratio (RR) and 95% confidence intervals (CI) were used to represent the results which were generated.

RESULTS

Three studies with a total number of 22,574 participants enrolled from years 2013 to 2019 were included in this analysis. Results of this analysis showed that DM was associated with significantly higher risks of major adverse cardiovascular events (RR: 1.73, 95% CI: 1.49 - 2.00; P = 0.00001), all-cause mortality (RR: 2.15, 95% CI: 1.73 - 2.66; P = 0.00001), cardiac death (RR: 2.82, 95% CI: 1.42 - 5.60; P = 0.003), stroke (RR: 1.78, 95% CI: 1.16 - 2.74; P = 0.009), myocardial infarction (RR: 1.63, 95% CI: 1.17 - 2.26; P = 0.004) and stent thrombosis (RR: 1.74, 95% CI: 1.03 - 2.94; P = 0.04) when compared to patients without DM. However, thrombolysis in myocardial infarction (TIMI) defined minor and major bleedings, bleeding defined according to the academic research consortium (BARC) type 3c (RR: 1.31, 95% CI: 0.14 - 11.90; P = 0.81) and BARC type 2, 3 or 5 (RR: 1.17, 95% CI: 0.85 - 1.62; P = 0.34) were not significantly different.

CONCLUSION

In patients who were treated with ticagrelor monotherapy after a short course of DAPT with ticagrelor and aspirin, DM was an independent risk factor for the significantly increased adverse cardiovascular outcomes. However, TIMI and BARC defined bleeding events were not significantly different in patients with versus without DM.

Stopping Aspirin Within 1 Month After Stenting for Ticagrelor Monotherapy in Acute Coronary Syndrome: The T-PASS Randomized Noninferiority Trial

BACKGROUND

Stopping aspirin within 1 month after implantation of a drug-eluting stent for ticagrelor monotherapy has not been exclusively evaluated for patients with acute coronary syndrome. The aim of this study was to investigate whether ticagrelor monotherapy after <1 month of dual antiplatelet therapy (DAPT) is noninferior to 12 months of ticagrelor-based DAPT for adverse cardiovascular and bleeding events in patients with acute coronary syndrome.

METHODS

In this randomized, open-label, noninferiority trial, 2850 patients with acute coronary syndrome who underwent drug-eluting stent implantation at 24 centers in South Korea were randomly assigned (1:1) to receive either ticagrelor monotherapy (90 mg twice daily) after <1 month of DAPT (n=1426) or 12 months of ticagrelor-based DAPT (n=1424) between April 24, 2019, and May 31, 2022. The primary end point was the net clinical benefit as a composite of all-cause death, myocardial infarction, definite or probable stent thrombosis, stroke, and major bleeding at 1 year after the index procedure in the intention-to-treat population. Key secondary end points were the individual components of the primary end point.

RESULTS

Among 2850 patients who were randomized (mean age, 61 years; 40% ST-segment-elevation myocardial infarction), 2823 (99.0%) completed the trial. Aspirin was discontinued at a median of 16 days (interquartile range, 12-25 days) in the group receiving ticagrelor monotherapy after <1 month of DAPT. The primary end point occurred in 40 patients (2.8%) in the group receiving ticagrelor monotherapy after <1-month DAPT, and in 73 patients (5.2%) in the ticagrelor-based 12-month DAPT group (hazard ratio, 0.54 [95% CI, 0.37-0.80]; P<0.001 for noninferiority; P=0.002 for superiority). This finding was consistent in the per-protocol population as a sensitivity analysis. The occurrence of major bleeding was significantly lower in the ticagrelor monotherapy after <1-month DAPT group compared with the 12-month DAPT group (1.2% versus 3.4%; hazard ratio, 0.35 [95% CI, 0.20-0.61]; P<0.001).

CONCLUSIONS

This study provides evidence that stopping aspirin within 1 month for ticagrelor monotherapy is both noninferior and superior to 12-month DAPT for the 1-year composite outcome of death, myocardial infarction, stent thrombosis, stroke, and major bleeding, primarily because of a significant reduction in major bleeding, among patients with acute coronary syndrome receiving drug-eluting stent implantation. Low event rates, which may suggest enrollment of relatively non-high-risk patients, should be considered in interpreting the trial.

REGISTRATION

URL: https://www.clinicaltrials.gov; Unique identifier: NCT03797651.

Ticagrelor for patients undergoing coronary artery bypass grafting: A meta-analysis of randomized controlled trials

OBJECTIVE

Ticagrelor may be an alternative to aspirin as it provides robust and consistent platelet inhibition. However, the effect of ticagrelor treatment in patients undergoing coronary artery bypass grafting (CABG) has not been well confirmed. We conducted a meta-analysis to appraise whether ticagrelor therapy affects outcomes in CABG patients.

METHODS

We searched PubMed, Embase, EBSCO, and Cochrane databases from its inception up to 4 December 2020 for randomized controlled trials that assessed ticagrelor versus non-ticagrelor in patients undergoing CABG. The primary outcome was the incidence of saphenous vein graft (SVG) occlusion at 1 year after CABG. Secondary outcomes were SVG occlusion at 7 days, major adverse cardiovascular events (MACE), and bleeding requiring reoperation.

RESULTS

Seven trials including 4305 patients (2153 randomized to ticagrelor therapy and 2152 to non-ticagrelor therapy) were included. One-hundred and thirty of 1140 patients (11.4%) randomized to the ticagrelor group versus 175 of 1220 patients (14.3%) randomized to the non-ticagrelor group experienced SVG occlusion at 1 year after CABG. Compared to the control group, ticagrelor therapy yielded a significantly lower risk of SVG occlusion [RR 0.79 (0.64-0.97), p = 0.03]. In the subgroup analysis, ticagrelor plus aspirin compared with aspirin alone did not decrease the risk of SVG occlusion after 1 year [RR 0.65 (0.40-1.07), p = 0.09]. There was no difference in the incidence of SVG occlusion at 7 days [RR 0.67 (0.42-1.06), p = 0.09], MACE up to 1 year [RR 0.99 (0.81-1.21), p = 0.90], or bleeding requiring reoperation [RR 1.16 (0.80-1.70), p = 0.44].

CONCLUSIONS

Compared with non-ticagrelor therapy, ticagrelor decreased the risk of saphenous vein graft occlusion after 1 year in patients undergoing elective CABG with saphenous vein grafting.

Outcomes of prolonged dual anti-platelet therapy in patients with acute coronary syndrome undergoing percutaneous coronary intervention: A nationwide registry-based study

BACKGROUND

Randomized controlled trials have shown a reduced risk of ischemic events and an increased risk of bleeding in patients treated with prolonged dual anti-platelet therapy (DAPT) beyond 12 months following acute coronary syndrome (ACS). We aimed to investigate outcomes of prolonged DAPT vs aspirin monotherapy (ASA) in a real-world population.

METHODS AND RESULTS

Using nationwide registries, we identified all patients with ACS who underwent percutaneous coronary intervention and received 12-month DAPT between January 2013 and October 2016. Patients still on DAPT were compared to patients on ASA at index date (15 months after ACS-date) and followed for up to 2 years. Cox regression models were employed to calculate standardized risks of all-cause mortality, major adverse cardiovascular event (MACE), and major bleeding. The study included 7,449 patients, 1,901 on DAPT (median age 66, 72.1% male) and 5,548 on ASA (median age 65, 75.1% male). Standardized absolute 2-year risk of all-cause mortality, MACE, and major bleeding was 2.7%, 3.7%, and 5.4% for DAPT vs 2.2%, 3.8%, and 1.3% for ASA. DAPT was not associated with a significant standardized 2-year risk difference (SRD) of all-cause mortality (SRD: 0.5%, 95% confidence interval [CI]: -0.9 to 1.7) or MACE (SRD: -0.1%, 95% CI -1.8 to 1.6), but a significantly higher risk of major bleeding (SRD: 4.1%, 95% CI 1.8-6.6).

CONCLUSIONS

In a nationwide cohort of ACS patients undergoing percutaneous coronary intervention, prolonged DAPT was not significantly associated with a reduced risk of all-cause mortality or MACE, but an increased risk of major bleeding. Future randomized controlled trials should investigate the optimal anti-platelet regimen in this patient group.

Aspirin-free antiplatelet regimens after PCI: insights from the GLOBAL LEADERS trial and beyond

Historically, aspirin has been the primary treatment for the prevention of ischaemic events in patients with coronary artery disease. For patients undergoing percutaneous coronary intervention (PCI) standard treatment has been 12 months of dual antiplatelet therapy (DAPT) with aspirin and clopidogrel, followed by aspirin monotherapy; however, DAPT is undeniably associated with an increased risk of bleeding. For over a decade novel P2Y₁₂ inhibitors, which have increased specificity, potency, and efficacy have been available, prompting studies which have tested whether these newer agents can be used in aspirin-free antiplatelet regimens to augment clinical benefits in patients post-PCI. Among these studies, the GLOBAL LEADERS trial is the largest by cohort size, and so far has provided a wealth of evidence in a variety of clinical settings and patient groups. This article summarizes the state-of-the-art evidence obtained from the GLOBAL LEADERS and other trials of aspirin-free strategies.