Antiplatelet Strategies Following PCI: A Review of Trials Informing Current and Future Therapies

Dual antiplatelet therapy (DAPT) has been paramount in preventing thrombosis following percutaneous coronary intervention for nearly 3 decades. However, over the years, DAPT has seen significant changes in the agents utilized and duration of therapy as trials have raced to keep up with advancements made in stent technology and our understanding of bleeding and ischemic risk. Recently, there have been a number of trials demonstrating significant reductions in bleeding events with shorter DAPT durations, which are not yet reflected in practice guidelines. Further, there has been a shift toward more individualized antiplatelet regimens to meet patient-specific risk profiles. This review provides a comprehensive summary of the major trials that have informed current DAPT strategies, puts into context recent trials driving a shift toward more tailored antiplatelet regimens, and highlights gaps in knowledge that remain and the ongoing trials designed to address them.

P2Y12 inhibitor monotherapy in patients undergoing percutaneous coronary intervention

For 20 years, dual antiplatelet therapy (DAPT), consisting of the combination of aspirin and a platelet P2Y₁₂ receptor inhibitor, has been the gold standard of antithrombotic pharmacology after percutaneous coronary intervention (PCI). In the past 5 years, several investigations have challenged this paradigm by testing the efficacy and safety of P2Y₁₂ inhibitor monotherapy (that is, without aspirin) following a short course of DAPT. Collectively, these studies suggested a reduction in the risk of major bleeding and no significant increase in thrombotic or ischaemic events compared with guideline-recommended DAPT. Current recommendations are evolving to inform clinical practice on the ideal candidates for P2Y₁₂ inhibitor monotherapy after PCI. Generalizing the results of studies of P2Y₁₂ inhibitor monotherapy requires a thorough understanding of their design, populations, interventions, comparators and results. In this Review, we provide an up-to-date overview on the use of P2Y₁₂ inhibitor monotherapy after PCI, including supporting pharmacodynamic and clinical evidence, practical recommendations and future directions.

Efficacy and Safety of Dual Antiplatelet Therapy in Patients Undergoing Coronary Stent Implantation: A Systematic Review and Network Meta-Analysis

Introduction

This network meta-analysis aimed to evaluate the efficacy and safety of different dual antiplatelet therapies (DAPTs) after percutaneous coronary intervention (PCI) with drug-eluting stents (DESs).

Methods

Randomized controlled trials (RCTs) comparing longer-term (>12 months) DAPT (L-DAPT), 12-month DAPT (DAPT 12Mo), 6-month DAPT (DAPT 6Mo), 3-month DAPT followed by aspirin monotherapy (DAPT 3Mo + ASA), 3-month DAPT followed by a P2Y12 receptor inhibitor monotherapy (DAPT 3Mo + P2Y12), or 1-month DAPT with a P2Y12 receptor inhibitor monotherapy (DAPT 1Mo + P2Y12) were searched. Primary endpoints were all-cause mortality, cardiac death, myocardial infarction (MI), major bleeding, any bleeding, definite or probable stent thrombosis (ST), and net adverse clinical events (NACE). This Bayesian network meta-analysis was performed with the random-effects model.

Results

Twenty-four RCTs (n = 81339) were included. In comparison with L-DAPT, DAPT 6Mo (OR: 0.50, 95% CI: 0.29–0.83), DAPT 3Mo + P2Y12 (OR: 0.38, 95% CI: 0.18–0.82), DAPT 3Mo + ASA (OR: 0.44, 95% CI: 0.17–0.98), and DAPT 1Mo + P2Y12 (OR: 0.45, 95% CI: 0.14–0.93) were associated with a lower risk of major bleeding. DAPT 3Mo + P2Y12 (OR: 0.58, 95% CI: 0.38–0.88) reduced the risk of any bleeding when compared with DAPT 12Mo. L-DAPT decreased the risk of MI and definite or probable stent ST when compared with DAPT 6Mo. DAPT 3Mo + P2Y12 decreased the risk of NACE in comparison with DAPT 6Mo and DAPT 12Mo. No significant difference in all-cause mortality and cardiac death was observed. In patients with acute coronary syndrome, DAPT 6Mo was comparable to DAPT 12Mo.

Conclusion

Short-term (1–3 months) DAPT is noninferior to DAPT 6Mo after DESs implantation, while L-DAPT reduces MI and definite or probable ST rates. DAPT 3Mo + P2Y12 might be a reasonable trade-off in patients with high risk of bleeding accompanied by ischemia.

Duration of dual antiplatelet therapy and subsequent monotherapy type in patients undergoing drug eluting stent implantation: a network Meta-analysis

AIMS

To compare safety and efficacy of very short (≤3 months), short (6 months), standard (12 months) and extended (>12 months) DAPT, and subsequent monotherapies, after DES.

METHODS AND RESULTS

Twenty-two RCT (n = 110059 patients/year) were selected and included in a Bayesian network meta-analysis. The primary efficacy endpoint (PEP) was a composite of cardiac death, myocardial infarction (MI) and stent thrombosis (ST), the primary safety endpoint was major bleeding. Compared to standard, we found lower rate of MI (OR 0.56, 95% CI 0.44-0.77) in extended DAPT; lower rate of major bleeding (OR 0.61, 95% CI 0.39-0.87) in very short and lower rate of any bleeding (OR 0.61, 95% CI 0.38-0.90) in short DAPT. All DAPT durations were comparable regarding the secondary efficacy endpoints. Very short followed by P2Y12 inhibition was the treatment of choice to reduce both major bleeding and myocardial infarction. In the ACS subgroup, extended (as compared to standard DAPT) reduced PEP and ST (but not MI).

CONCLUSION

The efficacy of short and very short is comparable with that of standard DAPT after DES implantation, whereas extended DAPT reduces MI rate. Very short DAPT reduces haemorrhagic events and, followed by a P2Y12 inhibitor monotherapy, may be preferred in order to pursue a trade-off between major bleeding and ischemia.

P2Y12 inhibitors monotherapy after short course of dual antiplatelet therapy in patients undergoing percutaneous coronary intervention: a meta-analysis of randomized clinical trials including 29 089 patients

AIMS

Dual antiplatelet therapy (DAPT) reduces the incidence of thrombotic complications at the cost of an increase in bleedings. New antiplatelet therapies focused on minimizing bleeding and maximizing antithrombotic effects are emerging. The aim of this study is to collect the current evidence coming from randomized controlled trials (RCTs) on early aspirin interruption after percutaneous coronary intervention (PCI) and current drug-eluting stent (DES) implantation and to perform a meta-analysis in order to evaluate the safety and efficacy of this strategy.

METHODS AND RESULTS

MEDLINE/PubMed was systematically screened for RCTs comparing P2Y12 inhibitors (P2Y12i) monotherapy after a maximum of 3 months of DAPT (S-DAPT) vs. DAPT for 12 months (DAPT) in patients undergoing PCI with DES. Baseline features were appraised. Major adverse cardiac and cerebrovascular events (MACCE: all causes of death, myocardial infarction, and stroke) and its single composites, stent thrombosis (ST) and Bleeding Academic Research Consortium (BARC) type 3 or 5 were considered and pooled with fixed and random-effects with inverse-variance weighting. A total of four RCTs including a total of 29 089 patients were identified. Overall, the majority of included patients suffered a stable coronary artery disease, while ST-elevation myocardial infarction was the least represented clinical presentation. Complex anatomical settings like left main intervention, bifurcations, and multi-lesions treatment were included although representing a minor part of the cases. At 1-year follow-up, MACCE rate was similar [odds ratio (OR) 0.90; 95% confidence intervals (CIs) 0.79-1.03] and any of its composites (all causes of death rate: OR 0.87; 95% CIs 0.71-1.06; myocardial infarction: OR 1.06; 95% CIs 0.90-1.26; stroke: OR 1.12; 95% CIs 0.82-1.53). Similarly, also ST rate was comparable in the two groups (OR 1.17; 95% CIs 0.83-1.64), while BARC 3 or 5 bleeding resulted significantly lower, adopting an S-DAPT strategy (OR 0.70; 95% CIs 0.58-0.86).

CONCLUSION

After a PCI with current DES, an S-DAPT strategy followed by a P2Y12i monotherapy was associated with a lower incidence of clinically relevant bleeding compared to 12 months DAPT, with no significant differences in terms of 1-year cardiovascular events.

Early Aspirin Discontinuation Following Acute Coronary Syndrome or Percutaneous Coronary Intervention: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

The respective ischemic and bleeding risks of early aspirin discontinuation following an acute coronary syndrome (ACS) or percutaneous coronary intervention (PCI) remain uncertain. We performed a prospero-registered review of randomized controlled trials (RCTs) comparing a P2Y₁₂ inhibitor-based single antiplatelet strategy following early aspirin discontinuation to a strategy of sustained dual antiplatelet therapy (DAPT) in ACS or PCI patients requiring, or not, anticoagulation for another indication (CRD42019139576). We estimated risk ratios (RR) and 95% confidence intervals (CI) using random effect models. We included nine RCTs comprising 40,621 patients. Compared to prolonged DAPT, major bleeding (2.2% vs. 2.8%; RR 0.68; 95% CI: 0.54 to 0.87; p = 0.002; I²: 63%), non-major bleeding (5.0 % vs. 6.1 %; RR: 0.66; 95% CI: 0.47 to 0.94; p = 0.02; I²: 87%) and all bleeding (7.4% vs. 9.9%; RR: 0.65; 95% CI: 0.53 to 0.79; p < 0.0001; I²: 88%) were significantly reduced with early aspirin discontinuation without significant difference for all-cause death (p = 0.60), major adverse cardiac and cerebrovascular events (MACE) (p = 0.60), myocardial infarction (MI) (p = 0.77), definite stent thrombosis (ST) (p = 0.63), and any stroke (p = 0.59). In patients on DAPT after an ACS or a PCI, early aspirin discontinuation prevents bleeding events with no significant adverse effect on the ischemic risk or mortality.

Impact of renal function on clinical outcomes after PCI in ACS and stable CAD patients treated with ticagrelor: a prespecified analysis of the GLOBAL LEADERS randomized clinical trial

BACKGROUND

Impaired renal function (IRF) is associated with increased risks of both ischemic and bleeding events. Ticagrelor has been shown to provide greater absolute reduction in ischemic risk following acute coronary syndrome (ACS) in those with versus without IRF.

METHODS

A pre-specified sub-analysis of the randomized GLOBAL LEADERS trial (n = 15,991) comparing the experimental strategy of 23-month ticagrelor monotherapy (after 1-month ticagrelor and aspirin dual anti-platelet therapy [DAPT]) with 12-month DAPT followed by 12-month aspirin after percutaneous coronary intervention (PCI) in ACS and stable coronary artery disease (CAD) patients stratified according to IRF (glomerular filtration rate < 60 ml/min/1.73 m²).

RESULTS

At 2 years, patients with IRF (n = 2171) had a higher rate of the primary endpoint (all-cause mortality or centrally adjudicated, new Q-wave myocardial infarction [MI](hazard ratio [HR] 1.64, 95% confidence interval [CI] 1.35-1.98, p_adj = 0.001), all-cause death, site-reported MI, all revascularization and BARC 3 or 5 type bleeding, compared with patients without IRF. Among patients with IRF, there were similar rates of the primary endpoint (HR 0.82, 95% CI 0.61-1.11, p = 0.192, p_int = 0.680) and BARC 3 or 5 type bleeding (HR 1.10, 95% CI 0.71-1.71, p = 0.656, p_int = 0.506) in the experimental versus the reference group. No significant interactions were seen between IRF and treatment effect for any of the secondary outcome variables. Among ACS patients with IRF, there were no between-group differences in the rates of the primary endpoint or BARC 3 or 5 type bleeding; however, the rates of the patient-oriented composite endpoint (POCE) of all-cause death, any stroke, MI, or revascularization (p_int = 0.028) and net adverse clinical events (POCE and BARC 3 or 5 type bleeding) (p_int = 0.045), were lower in the experimental versus the reference group. No treatment effects were found in stable CAD patients categorized according to presence of IRF.

CONCLUSIONS

IRF negatively impacted long-term prognosis after PCI. There were no differential treatment effects found with regard to all-cause death or new Q-wave MI after PCI in patients with IRF treated with ticagrelor monotherapy.

CLINICAL TRIAL REGISTRATION

The trial has been registered with ClinicalTrials.gov, number NCT01813435.