Impact of greater than 12-month dual antiplatelet therapy duration on mortality: Drug-specific or a class-effect? A meta-analysis

Individualization of Duration of Dual Antiplatelet Therapy after Coronary Stenting: A Comprehensive, Evidence-Based Review

Dual antiplatelet therapy (DAPT), comprising aspirin and a P2Y12 receptor inhibitor, is the cornerstone of post-percutaneous coronary intervention treatment to prevent stent thrombosis and reduce the risk of adverse cardiovascular events. The selection of an optimal DAPT regimen, considering the interplay of various antiplatelet agents, patient profiles, and procedural characteristics, remains an evolving challenge. Traditionally, a standard duration of 12 months has been recommended for DAPT in most patients. While contemporary guidelines provide general frameworks, DAPT modulation with longer or shorter treatment courses followed by aspirin or P2Y12 inhibitor monotherapy are evolving towards an individualized strategy to optimize the balance between efficacy and safety. This review comprehensively examines the current landscape of DAPT strategies after coronary stenting, with a focus on emerging evidence for treatment individualization.

Complexity of Antiplatelet Therapy in Coronary Artery Disease Patients

Patients with coronary artery disease (CAD) presenting with acute coronary syndrome or undergoing coronary stenting are indicated to treatment with dual antiplatelet therapy (DAPT) combining aspirin with a P2Y12 receptor inhibitor. The management of patients with CAD who present with a complex clinical profile due to multiple comorbidities, and/or undergoing complex interventional procedures, remains challenging as a high risk for both ischemic and bleeding events is often present; hence, the risk-benefit balance on the optimal DAPT duration is difficult to evaluate. The complexity of antiplatelet therapy in CAD patients is due to the fact that this complexity embraces several aspects: the coronary anatomy, the number of vascular districts at risk for atherothrombosis, and patient comorbidities, including global frailty. Recent randomized and epidemiological studies have highlighted subgroups that could benefit from prolonged antithrombotic treatment, as well as frail patients, who may be better suited to a shorter course of therapy. We provide an overview of the current knowledge regarding treatment with DAPT, along with suggestions on its management.

The High Bleeding Risk Patient with Coronary Artery Disease

Out-of-hospital bleeding is a common complication after percutaneous coronary intervention (PCI) due to the concomitant need for dual antiplatelet therapy. A significant proportion of patients undergoing PCI carry specific clinical characteristics posing them at high bleeding risk (HBR), increasing the risk of hemorrhagic complications secondary to antithrombotic therapy. Identifying patients at HBR and adjust antithrombotic therapy accordingly to optimize treatment benefits and risk is a challenge of modern cardiology. Recently, multiple definitions and tools have been provided to help clinicians with prognostic stratification and treatment decision making in this subgroup.

A 4-item PRECISE-DAPT score for dual antiplatelet therapy duration decision-making

The originally-proposed PRECISE-DAPT score is a 5-item risk score supporting decision-making for dual antiplatelet therapy¹ duration after PCI. It is unknown if a simplified version of the score based on 4 factors (age, hemoglobin, creatinine clearance, prior bleeding), and lacking white-blood cell count, retains potential to guide DAPT duration. The 4-item PRECISE-DAPT was used to categorize 10,081 patients who were randomized to short (3-6 months) or long (12-24 months) DAPT regimen according to high (HBR defined by PRECISE-DAPT ≥25 points) or non-high bleeding risk (PRECISE-DAPT<25) status. Long treatment duration was associated with higher bleeding rates in HBR (ARD +2.22% [95% CI +0.53 to +3.90]) but not in non-HBR patients (ARD +0.25% [-0.14 to +0.64]; p_int = 0.026), and associated with lower ischemic risks in non-HBR (ARD -1.44% [95% CI -2.56 to -0.31]), but not in HBR patients (ARD +1.16% [-1.91 to +4.22]; p_int = 0.11). Only non-HBR patients experienced lower net clinical adverse events (NACE) with longer DAPT (p_int = 0.043). A 4-item simplified version of the PRECISE-DAPT score retains the potential to categorize patients who benefit from prolonged DAPT without concomitant bleeding liability from those who do not.

Antithrombotic Therapy for Percutaneous Cardiovascular Interventions: From Coronary Artery Disease to Structural Heart Interventions

Percutaneous cardiovascular interventions have changed dramatically in recent years, and the impetus given by the rapid implementation of novel techniques and devices have been mirrored by a refinement of antithrombotic strategies for secondary prevention, which have been supported by a significant burden of evidence from clinical studies. In the current manuscript, we aim to provide a comprehensive, yet pragmatic, revision of the current available evidence regarding antithrombotic strategies in the domain of percutaneous cardiovascular interventions. We revise the evidence regarding antithrombotic therapy for secondary prevention in coronary artery disease and stent implantation, the complex interrelation between antiplatelet and anticoagulant therapy in patients undergoing percutaneous coronary intervention with concomitant atrial fibrillation, and finally focus on the novel developments in the secondary prevention after structural heart disease intervention. A special focus on treatment individualization is included to emphasize risk and benefits of each therapeutic strategy.

Dual Antiplatelet Therapy Duration: Reconciling the Inconsistencies

Dual antiplatelet therapy (DAPT) prevents recurrent ischemic events after an acute coronary syndrome (ACS) as well as stent thrombosis (ST) in patients with prior stent implantation. Nevertheless, these benefits are counterbalanced by a significant bleeding hazard, which is directly related to the treatment duration. Although DAPT has been extensively studied in numerous clinical trials, optimal treatment duration is still debated, mostly because of apparent inconsistencies among studies. Shortened treatment duration of 6 or 3 months was shown to mitigate bleeding risk compared with consensus-grounded 12-month standard duration, without any apparent excess of ischemic events. However, recent trials showed that a >12-month course of treatment reduces ischemic events but increases bleeding compared with 12 months. The inconsistent benefit of a longer DAPT course compared with shorter treatment durations is puzzling, and requires a careful appraisal of between-studies differences. We sought to summarize the existing evidence aiming at reconciling apparent inconsistencies among these studies, as well as thoroughly discuss the possible increased risk of fatal events associated with long-term DAPT. Benefits and risks of prolonging or shortening DAPT duration will be discussed, with a focus on treatment individualization. Finally, we will provide an outlook for possible future directions in the field.

The optimal duration of dual antiplatelet therapy after coronary stent implantation: to go too far is as bad as to fall short

Dual antiplatelet therapy (DAPT) with aspirin and a P2Y12 inhibitor is key for secondary prevention of recurrent coronary ischemic events and stent thrombosis. For this purpose, DAPT showed superior efficacy compared to aspirin alone, but it is also associated with an increased risk of major, and potentially fatal, bleeding. Hence, while secondary prevention with aspirin monotherapy is generally maintained for an indefinite period, the duration of DAPT after the index event is still debated. Multiple trials have challenged the guideline recommended standard of care of 12 months of DAPT duration. These studies tested on one side a treatment reduction to 6 or 3 months, and on the other side an extension of treatment beyond 12 months in order to define the optimal DAPT duration maximizing the anti-ischemic protection and minimizing bleeding. In this document we sought to summarize the existing evidence from more than 18 randomized controlled trials in the field, and discuss the benefit and risks of prolonging/shortening DAPT duration. In addition, a specific focus on treatment individualization will outline the current, evidence-based, decision-making process for optimal DAPT duration selection after coronary stenting.

Practical issues in clinical scenarios involving CKD patients requiring antithrombotic therapy in light of the 2017 ESC guideline recommendations

BACKGROUND

The choice of the most appropriate antithrombotic regimen that balances ischemic and bleeding risks was addressed by the August 2017 European Society of Cardiologists (ESC)/European Association for Cardio-Thoracic Surgery Focused Update recommendations, which propose new evaluation scores and protocols for patients requiring a coronary stent or patients with an acute coronary syndrome, atrial fibrillation, or a high bleeding risk and indication for oral anticoagulation therapy.

DISCUSSION

Numerous questions remain regarding antithrombotic regimens and risk management algorithms for both ischemic and hemorrhagic events in patients with chronic kidney disease (CKD) in various clinical scenarios. Limitations of current studies include a general ack of advanced CKD patients in major randomized controlled trials, of evidence on algorithm implementation, and of robust assessment tools for hemorrhagic risk. Herein, we aim to analyze the ESC Update recommendations and the newly implemented risk scores (DAPT, PRECISE-DAPT, PARIS) from the point of view of CKD, providing suggestions on drug choice (which combination has the best evidence), dosage, and duration (the same or different as for non-CKD population) of antithrombotics, as well as to identify current shortcomings and to envision directions of future research.

CONCLUSION

We provide an evidence-based perspective on the new proposed bleeding management protocol, with focus on the CKD population. Despite previous important steps on antithrombotic therapy of renal patients, there remain many unsolved questions for which our suggestions could fundament new randomized controlled trials and specific protocols.

Long-Term Use of Ticagrelor in Patients with Coronary Artery Disease

PURPOSE OF REVIEW

This review aims to summarize and discuss safety and effectiveness of the long-term use of ticagrelor in patients with coronary artery disease (CAD).

RECENT FINDINGS

Ticagrelor is an orally administered, direct, and reversible inhibitor of the P2Y₁₂-platelet receptor. Long-term use of ticagrelor in patients with previous myocardial infarction (MI) has been investigated in the PEGASUS-TIMI-54 trial. Overall, 21,162 patients with a spontaneous MI 1 to 3 years before randomization were randomly assigned to ticagrelor 90 mg bid, ticagrelor 60 mg bid, or placebo. Compared with placebo, both doses of ticagrelor showed that they were capable of significantly reducing the primary efficacy endpoint, although with a significant increase in TIMI major bleeding. Intracranial hemorrhage or fatal bleeding did not differ across groups. These findings establish clear benefit of DAPT extension with ticagrelor beyond 1 year of treatment, which comes with a tradeoff of clinically meaningful bleeding. Altogether, current evidence suggests that the duration of DAPT remains a patient-by-patient decision based on thrombotic and bleeding risk profiles.

Cost-Effectiveness of Long-Term Ticagrelor in Patients With Prior Myocardial Infarction: Results From the PEGASUS-TIMI 54 Trial

BACKGROUND

In patients with a myocardial infarction (MI) 1 to 3 years earlier, treatment with ticagrelor + low-dose aspirin (ASA) reduces the risk of cardiovascular (CV) death, MI, or stroke compared with low-dose aspirin alone, but at an increased risk of major bleeding.

OBJECTIVES

The authors evaluated cost-effectiveness of ticagrelor + low-dose ASA in patients with prior MI within the prior 3 years.

METHODS

The authors performed a prospective economic substudy alongside the PEGASUS-TIMI 54 (Prevention of Cardiovascular Events in Patients With Prior Heart Attack Using Ticagrelor Compared to Placebo on a Background of Aspirin-Thrombolysis In Myocardial Infarction 54) trial, which randomized 21,162 patients to ASA alone, ticagrelor 60 mg twice daily + low-dose ASA, or ticagrelor 90 mg twice daily + low-dose ASA. Medical resource use data were collected over a median 33-month follow-up. Costs were assessed from the U.S. health care system perspective. In-trial data relating to survival, utility, and costs were combined with lifetime projections to evaluate lifetime cost-effectiveness of the Food and Drug Administration-approved lower-dose ticagrelor regimen (60 mg twice daily).

RESULTS

Hospitalization costs were similar for ticagrelor 60 mg and placebo ($2,262 vs. $2,333; 95% confidence interval for difference -$303 to $163; p = 0.54); after inclusion of a daily ticagrelor 60 mg cost of $10.52, total costs were higher for ticagrelor ($10,016 vs. $2,333; 95% CI: $7,441 to $7,930; p < 0.001). In-trial quality-adjusted life-years (QALYs) were similar (2.28 vs. 2.27; p = 0.34). Over a lifetime horizon, ticagrelor was associated with QALY gains of 0.078 and incremental costs of $7,435, yielding an incremental cost-effectiveness ratio (ICER) of $94,917/QALY gained. Several high-risk groups had more favorable ICERs, including patients with >1 prior MI, multivessel disease, diabetes, renal dysfunction (all with ICERs $50,000 to $70,000/QALY gained), patients age <75 years (ICER = $44,779/QALY gained), and patients with peripheral artery disease (ICER = $13,427/QALY gained).

CONCLUSIONS

For patients with a history of MI >1 year previously, long-term treatment with ticagrelor 60 mg + low-dose ASA yields a cost-effectiveness ratio suggesting intermediate value based on current guidelines. Ticagrelor appears to provide higher value for patients in several recognized high-risk subgroups. (Prevention of Cardiovascular Events [e.g., Death From Heart or Vascular Disease, Heart Attack, or Stroke] in Patients With Prior Heart Attack Using Ticagrelor Compared to Placebo on a Background of Aspirin [PEGASUS]; NCT01225562).

A Critical Appraisal of Aspirin in Secondary Prevention: Is Less More?

Aspirin represents the sine qua non for antiplatelet pharmacotherapy in patients with cardiovascular diseases because of its well-established role in secondary prevention and its widespread availability and affordability. Historical studies, conducted in an era that bears little resemblance to contemporary clinical practice, demonstrated large reductions in thrombotic risk when aspirin was compared with placebo, thus forming the evidence base promulgated in practice guidelines and recommendations. P2Y₁₂ inhibitors have mostly been studied in addition to aspirin; dual-antiplatelet therapy proved superiority compared with aspirin monotherapy for the prevention of ischemic events, despite increased bleeding risks. An alternative approach currently under investigation includes evaluation of single-antiplatelet therapy with P2Y₁₂ inhibitors alone versus dual-antiplatelet therapy after acute coronary syndromes or coronary stent implantation. As the availability of more effective antiplatelet agents increases, it is time to revisit the existing and long-standing paradigm supporting aspirin use for secondary prevention of atherothrombotic events. Ongoing trials will provide new evidence whether the less-is-more strategy is justified.