P2Y12 inhibitor monotherapy versus aspirin monotherapy after short-term dual antiplatelet therapy for percutaneous coronary intervention: Insights from a network meta-analysis of randomized trials

Review of the Ticagrelor Trials Evidence Base

Ticagrelor is a platelet P2Y12 receptor inhibitor approved for use in patients with acute coronary syndromes, coronary artery disease, and low-moderate risk acute ischemic stroke or high-risk transient ischemic attack. Clinical trials have evaluated the efficacy and safety of ticagrelor on ischemic and bleeding outcomes for different indications and with varying treatment approaches. As a result, there is a large body of clinical evidence demonstrating different degrees of net clinical benefit compared with other platelet inhibitor drugs based on indication, patient characteristics, clinical presentation, treatment duration, and other factors. We provide a review of the major trials of ticagrelor in the context of other randomized trials of clopidogrel and prasugrel to organize the volume of available information, elevate corroborating and conflicting data, and identify potential gaps as areas for further exploration of optimal antiplatelet treatment.

Preferred monotherapy after short-term dual antiplatelet therapy: Systematic review and network meta-analysis of randomized trials

BACKGROUND

Randomized controlled trials (RCTs) have demonstrated the efficacy and safety of P2Y12 inhibitor monotherapy following short-term dual antiplatelet therapy (DAPT) in patients undergoing percutaneous coronary intervention (PCI). However, no studies have compared P2Y12 inhibitor and aspirin monotherapy following short-term DAPT. We aimed to compare available strategies for DAPT duration and post-DAPT antiplatelet monotherapy following PCI.

METHODS

Seven DAPT strategies [ticagrelor or clopidogrel following 1-month DAPT, ticagrelor following 3-month DAPT, aspirin following 3-6 months of DAPT (reference strategy), aspirin or P2Y12 inhibitor following 6-18-months of DAPT, and DAPT for ≥18 months] were compared using a network meta-analysis. The primary efficacy outcome was defined as a composite of all-cause death, myocardial infarction, and stroke. The primary bleeding outcome was trial-defined major or minor bleeding.

RESULTS

Our analysis identified 25 eligible RCTs, including 89,371 patients who underwent PCI. Overall, none of the strategies negatively affected the primary efficacy outcomes. For primary bleeding outcomes, ticagrelor following 3-month DAPT was associated with a reduced risk of primary bleeding outcomes (HR 0.73; 95 % CI 0.57-0.95). Clopidogrel following 1-month DAPT was also associated with a reduced risk of primary bleeding outcomes (HR 0.54; 95 % CI 0.34-0.85), however, the strategy was associated with an increased risk of myocardial infarction or stent thrombosis. Similar trends were observed among patients with acute coronary syndrome and high bleeding risk.

CONCLUSIONS

Compared with aspirin monotherapy following short-term DAPT, ticagrelor following 3-month DAPT was associated with a reduced risk of primary bleeding outcomes without increasing any ischemic outcomes.

Clopidogrel Monotherapy versus Aspirin Monotherapy in Patients with Established Cardiovascular Disease: Systematic Review and Meta-Analysis

BACKGROUND

 There is no clear consensus on whether aspirin offers better outcomes in terms of secondary cardiovascular disease prevention compared with clopidogrel.

OBJECTIVE

 The aim of the study was to compare the safety and efficacy of clopidogrel versus aspirin in patients with established cardiovascular disease.

METHODS

 A systematic review of MEDLINE (via PubMed), Scopus, and Cochrane Library databases (last search date: August 28, 2021) was performed according to the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-analyses) statement for randomized control trials (RCTs) of clopidogrel versus aspirin as monotherapy in patients with established cardiovascular disease. Random-effects meta-analyses were performed.

RESULTS

 Five RCTs incorporating 26,855 patients (clopidogrel: 13,426; aspirin: 13,429) were included. No statistically significant difference was observed between clopidogrel and aspirin in terms of all-cause mortality (odds ratio [OR]: 1.01 [95% confidence interval, CI: 0.91-1.13]; p = 0.83), ischemic stroke (OR: 0.87 [95% CI: 0.71-1.06]; p = 0.16), and major bleeding rates (OR: 0.77 [95% CI: 0.56-1.06]; p = 0.11). Patients receiving clopidogrel had borderline lower risk for major adverse cardiovascular events (MACE) (OR: 0.84 [95% CI: 0.71-1.00]; p = 0.05) and lower risk for nonfatal myocardial infarction (OR: 0.83 [95% CI: 0.71-0.97]; p = 0.02, relative risk reduction = 16.9%, absolute risk reduction = 0.5%, number needed to treat = 217 for a mean period of 20 months) compared with patients receiving aspirin.

CONCLUSION

 In patients with established cardiovascular disease, clopidogrel was associated with a 17% relative-risk reduction for nonfatal MI, borderline decreased risk for MACE, and similar risk for all-cause mortality, stroke, and major bleeding compared with aspirin.

PROTOCOL REGISTRATION

 PROSPERO CRD42021283866.

Challenges of long-term dual antiplatelet therapy use following acute coronary syndromes

An acute coronary syndrome (ACS) event is associated with a high risk of recurrent ACS, stroke, and death. To ameliorate the risk of subsequent events, current guidelines for ST-segment elevation myocardial infarction and non-ST-segment elevation ACS recommend long-term management strategies for secondary prevention including risk factor modification and anti-ischemic and antiplatelet therapies. Dual antiplatelet therapy (DAPT), comprising aspirin plus a P2Y₁₂ inhibitor, is a critical component of secondary prevention therapy following ACS. However, despite the importance of DAPT for secondary prevention after ACS, questions remain over the optimal duration of therapy. Clinical evidence is emerging that maintenance DAPT >12 months lowers the risk of recurrent ACS events; however, this benefit must be considered against any potential risks of prolonged DAPT such as bleeding. Several tools for bleeding risk assessment have shown promise; however, their limited accuracy and discriminative power necessitates further development. Assessment of patient ischemic risk should consider the complexity of the percutaneous coronary intervention (PCI) procedure, anatomic burden of coronary artery disease, and additional underlying risk factors. Consequently, identifying patients in whom the risk:benefit ratio favors prolonged DAPT may prove invaluable for clinicians in deciding which patients should continue or stop taking DAPT at 12 months after PCI, or consider P2Y₁₂ inhibitor monotherapy as an option. This article reviews the most recent information about the risks and benefits of DAPT continued for >12 months after ACS and provides critical guidance to assist physicians in identifying patients most likely to benefit from a secondary prevention strategy with DAPT.

P2Y12 inhibitor versus aspirin monotherapy for secondary prevention of cardiovascular events: meta-analysis of randomized trials

Aim

To compare the efficacy and safety of P2Y₁₂ inhibitor or aspirin monotherapy for secondary prevention in patients with atherosclerotic cardiovascular disease (ASCVD).

Methods and results

Medline, Embase, and Cochrane Central databases were searched to identify randomized trials comparing monotherapy with a P2Y₁₂ inhibitor versus aspirin for secondary prevention in patients with ASCVD (cardiovascular, cerebrovascular, or peripheral artery disease). The primary outcome was major adverse cardiac events (MACE). Secondary outcomes were myocardial infarction (MI), stroke, all-cause mortality, and major bleeding. A random-effects model was used to calculate risk ratios (RR) and the corresponding 95% confidence interval (CI) and heterogeneity among studies was assessed using the Higgins I² value. A total of 9 eligible trials (5 with clopidogrel and 4 with ticagrelor) with 61 623 patients were included in our analyses. Monotherapy with P2Y₁₂ inhibitors significantly reduced the risk of MACE by 11% (0.89, 95% CI 0.84-0.95, I² = 0%) and MI by 19% (0.81, 95% CI 0.71-0.92, I2 = 0%) compared with aspirin monotherapy. There was no significant difference in the risk of stroke (0.85, 95% CI 0.73-1.01), or all-cause mortality (1.01, 95% CI 0.92-1.11). There was also no significant difference in the risk of major bleeding with P2Y₁₂ inhibitor monotherapy compared with aspirin (0.94, 95% CI 0.72-1.22, I² = 42.6%). Results were consistent irrespective of the P2Y₁₂ inhibitor used.

Conclusion

P2Y₁₂ inhibitor monotherapy for secondary prevention is associated with a significant reduction in atherothrombotic events compared with aspirin alone without an increased risk of major bleeding.

Ticagrelor Monotherapy Versus Dual-Antiplatelet Therapy After PCI: An Individual Patient-Level Meta-Analysis

OBJECTIVES

The aim of this study was to compare ticagrelor monotherapy with dual-antiplatelet therapy (DAPT) after percutaneous coronary intervention (PCI) with drug-eluting stents.

BACKGROUND

The role of abbreviated DAPT followed by an oral P2Y₁₂ inhibitor after PCI remains uncertain.

METHODS

Two randomized trials, including 14,628 patients undergoing PCI, comparing ticagrelor monotherapy with standard DAPT on centrally adjudicated endpoints were identified, and individual patient data were analyzed using 1-step fixed-effect models. The protocol was registered in PROSPERO (CRD42019143120). The primary outcomes were the composite of Bleeding Academic Research Consortium type 3 or 5 bleeding tested for superiority and, if met, the composite of all-cause death, myocardial infarction, or stroke at 1 year, tested for noninferiority against a margin of 1.25 on a hazard ratio (HR) scale.

RESULTS

Bleeding Academic Research Consortium type 3 or 5 bleeding occurred in fewer patients with ticagrelor than DAPT (0.9% vs. 1.7%, respectively; HR: 0.56; 95% confidence interval [CI]: 0.41 to 0.75; p < 0.001). The composite of all-cause death, myocardial infarction, or stroke occurred in 231 patients (3.2%) with ticagrelor and in 254 patients (3.5%) with DAPT (HR: 0.92; 95% CI: 0.76 to 1.10; p < 0.001 for noninferiority). Ticagrelor was associated with lower risk for all-cause (HR: 0.71; 95% CI: 0.52 to 0.96; p = 0.027) and cardiovascular (HR: 0.68; 95% CI: 0.47 to 0.99; p = 0.044) mortality. Rates of myocardial infarction (2.01% vs. 2.05%; p = 0.88), stent thrombosis (0.29% vs. 0.38%; p = 0.32), and stroke (0.47% vs. 0.36%; p = 0.30) were similar.

CONCLUSIONS

Ticagrelor monotherapy was associated with a lower risk for major bleeding compared with standard DAPT, without a concomitant increase in ischemic events.

Short-term vs long-term dual antiplatelet therapy after drug-eluting stent implantation in patients undergoing percutaneous coronary intervention: A systematic review and meta-analysis

OBJECTIVE

The optimal duration of dual antiplatelet therapy (DAPT) after percutaneous coronary intervention (PCI) is under controversial. The aim of the present systematic review and meta-analysis was to evaluate the safety and efficacy of short-term (≤6 months) DAPT vs long-term (≥12 months) DAPT after PCI with a drug-eluting stent (DES).

METHODS

We systematically searched the Cochrane Library, PubMed and Embase databases to identify randomised controlled trials (RCTs) that compared short-term (≤6 months) and long-term (≥12 months) DAPT. The endpoints included major bleeding, any bleeding, death from any cause, cardiac death, myocardial infarction, stroke, stent thrombosis and target vessel revascularisation. The primary outcome was major bleeding. A fixed-effects model was used to calculate the risk ratio (RR) and 95% confidence interval (CI) of each endpoint.

RESULTS

Eighteen trials involving 57,940 patients were included. Compared with long-term DAPT, short-term DAPT resulted in lower rates of major bleeding [RR 0.75, 95% CI 0.65-0.87, P = .0002] and any bleeding [RR 0.61, 95% CI 0.54-0.69, P < .00001]. No significant difference was observed in the outcomes of death from any cause, cardiac death, myocardial infarction, stroke, stent thrombosis, or target vessel revascularisation. The subgroup analysis according to different DAPT durations, mono antiplatelet therapies (MAPTs), countries and P2Y12 inhibitors produced similar outcomes as comprehensive outcomes.

CONCLUSIONS

Compared with long-term DAPT, short-term DAPT did not increase the risk of ischemic complications but did reduce the risks of major bleeding and any bleeding by over 25%. This study showed that short-term DAPT could be considered for most patients after DES implantation.

P2Y12 inhibitor monotherapy or dual antiplatelet therapy after coronary revascularisation: individual patient level meta-analysis of randomised controlled trials

OBJECTIVE

To assess the risks and benefits of P2Y₁₂ inhibitor monotherapy compared with dual antiplatelet therapy (DAPT) and whether these associations are modified by patients' characteristics.

DESIGN

Individual patient level meta-analysis of randomised controlled trials.

DATA SOURCES

Searches were conducted in Ovid Medline, Embase, and three websites (www.tctmd.com, www.escardio.org, www.acc.org/cardiosourceplus) from inception to 16 July 2020. The primary authors provided individual participant data.

ELIGIBILITY CRITERIA

Randomised controlled trials comparing effects of oral P2Y₁₂ monotherapy and DAPT on centrally adjudicated endpoints after coronary revascularisation in patients without an indication for oral anticoagulation.

MAIN OUTCOME MEASURES

The primary outcome was a composite of all cause death, myocardial infarction, and stroke, tested for non-inferiority against a margin of 1.15 for the hazard ratio. The key safety endpoint was Bleeding Academic Research Consortium (BARC) type 3 or type 5 bleeding.

RESULTS

The meta-analysis included data from six trials, including 24 096 patients. The primary outcome occurred in 283 (2.95%) patients with P2Y₁₂ inhibitor monotherapy and 315 (3.27%) with DAPT in the per protocol population (hazard ratio 0.93, 95% confidence interval 0.79 to 1.09; P=0.005 for non-inferiority; P=0.38 for superiority; τ²=0.00) and in 303 (2.94%) with P2Y₁₂ inhibitor monotherapy and 338 (3.36%) with DAPT in the intention to treat population (0.90, 0.77 to 1.05; P=0.18 for superiority; τ²=0.00). The treatment effect was consistent across all subgroups, except for sex (P for interaction=0.02), suggesting that P2Y₁₂ inhibitor monotherapy lowers the risk of the primary ischaemic endpoint in women (hazard ratio 0.64, 0.46 to 0.89) but not in men (1.00, 0.83 to 1.19). The risk of bleeding was lower with P2Y₁₂ inhibitor monotherapy than with DAPT (97 (0.89%) v 197 (1.83%); hazard ratio 0.49, 0.39 to 0.63; P<0.001; τ²=0.03), which was consistent across subgroups, except for type of P2Y₁₂ inhibitor (P for interaction=0.02), suggesting greater benefit when a newer P2Y₁₂ inhibitor rather than clopidogrel was part of the DAPT regimen.

CONCLUSIONS

P2Y₁₂ inhibitor monotherapy was associated with a similar risk of death, myocardial infarction, or stroke, with evidence that this association may be modified by sex, and a lower bleeding risk compared with DAPT.

REGISTRATION

PROSPERO CRD42020176853.