Optimal duration of dual antiplatelet therapy after drug eluting stent implantation: a network meta-analysis

OBJECTIVE

There has been much debate regarding the optimal duration of dual antiplatelet therapy (DAPT) cover after drug eluting stent (DES) implantation. We aimed to assess the relative benefits of shorter and longer durations of DAPT coverage.

METHODS

We performed a network meta-analysis (NMA) of all the randomized clinical trials (RCT) comparing different time durations of DAPT cover.

RESULTS

We included 11 unique trials with a total of 33,458 patients; the longest duration of follow-up was 48 months and the shortest was 3 months. NMA results demonstrated that compared with 12 months, longer DAPT of 30 months reduced the hazard ratio (HR) of stent thrombosis (HR, 0.29; 95% CrI, 0.17-0.49). There was no difference in mortality between shorter and longer durations of DAPT except for 30 vs. 48 months (HR, 0.48; 95% CrI, 0.23-0.98). Compared with 12 months, longer DAPT of 30 months reduced the risk of myocardial infarction (HR, 0.47; 95% CrI, 0.37-0.61). Results also demonstrated that compared with 12 months, a shorter-term DAPT reduced the risk of major bleeding (6 months: HR, 0.53; 95% CrI, 0.29-0.98), whereas longer-term DAPT increased the risk of major bleeding (30 months: HR, 1.61; 95% CrI, 1.21-2.15).

CONCLUSION

As expected, bleeding was less in the shorter duration regimens, whereas the ischemic outcomes were better in the longer duration ones.

Cardiac Screening in the Noncardiac Surgery Patient

This article will address common cardiac conditions that require evaluation prior to noncardiac surgery, characterization of urgency and the risk associated with surgical procedures, calculation of preoperative risk assessment, indications for diagnostic testing to quantify cardiac risk, and perioperative strategies to minimize the risk of cardiac complications.

Should We Still Have Bare-Metal Stents Available in Our Catheterization Laboratory?

The introduction of bare-metal stents (BMS) has represented a major advancement over plain old balloon angioplasty in the management of coronary artery disease. However, the high rates of target lesion revascularization associated with use of BMS have led to the development of drug-eluting stents, which require prolonged dual antiplatelet therapy due to the increased risk of late and very late stent thrombosis. The improvements in newer-generation drug-eluting stents have translated into better safety and efficacy compared with earlier generation and BMS, thus allowing shorter dual antiplatelet therapy duration. Here, we aim to provide reasons as to why we still need BMS in our cardiac catheterization laboratory.

Clinical implications of blood-material interaction and drug eluting stent polymers in review

INTRODUCTION

Despite advances in drug-eluting stent (DES) technology, stent thrombosis (ST) remains the most feared complication with high morbidity and mortality. Areas covered: Stent related factors certainly play a role in the pathophysiology of ST and more recent data suggest coating technologies have the potential to favorable modify this risk though blood material interactions. Of the polymer coatings used in DES, fluorinated polymers in particular have shown significant promise in modifying the risk of ST through their preferential interactions with albumin which is believed to prevent the adhesion and aggregation of platelets to the stent surface and thus minimize thrombus formation. Preclinical data from the porcine arteriovenous fistula model and clinical data from large network meta-analysis support a role for fluorinated polymers in reducing ST. Expert commentary: The search for more biocompatible anti-thrombotic polymer coatings continues and it is likely that further modification of stent based surfaces will revolutionize the field of interventional cardiology by one day obviating the need for systemic anti-platelet therapies in patients receiving intravascular devices.

Stent thrombosis and optimal duration of dual antiplatelet therapy after coronary stenting in contemporary practice

The introduction of drug-eluting stents (DES) in the practice of percutaneous coronary intervention (PCI) has substantially reduced angiographic and clinical restenosis but is associated with an increasing propensity for very late stent thrombosis (ST). Among several clinical, lesion, or procedure-related predictors of ST, early discontinuation of dual antiplatelet therapy (DAPT) is the most important factor for DES-associated late thrombosis; therefore, the optimal duration of DAPT is a major issue to be critically considered in the current DES era. Given that the benefit and risk of longer duration DAPT should be simultaneously considered, the optimal DAPT period following DES implantation has been controversial. Several small-to-medium sized randomized clinical trials and observational registries have indicated that short-term DAPT (< 6 months) is not inferior to 12-month DAPT with fewer bleeding events, whereas prolonged duration of DAPT (> 12 months) failed to prove its superiority. However, compelling evidence from a landmark DAPT trial has clearly demonstrated the efficacy of prolonged DAPT up to 30 months in terms of preventing ST and major cardiovascular adverse events at the expense of major bleeding. In addition, coupled with various risk algorithms, a more individualized approach to balance the efficacy and safety of optimal DAPT duration has been emphasized. In this review article, we systematically summarize the cumulative evidence from key clinical studies and try to help the physician make decisions on the optimal duration of DAPT in contemporary PCI practice.

High risk of stent thrombosis in the first 6 months after coronary stenting: Do not discontinue clopidogrel early after ACS

OBJECTIVES

To estimate the incidence of stent thrombosis (ST) after early discontinuation of clopidogrel.

BACKGROUND

Premature discontinuation of clopidogrel is the strongest risk factor for ST. In contrast, recent studies suggest that shorter dual antiplatelet therapy (DAPT) can be discontinued as soon as 3 months after stenting. However, these studies included very few ACS patients and were not powered for ST. Hence, little is known about the occurrence of ST in high-risk populations when DAPT is discontinued early.

METHODS

This is a subanalysis of The Dutch ST Registry 437 ST cases (mainly first-generation DES and BMS). Acute coronary syndrome was the indication for index-PCI in 74% of the patients. Clopidogrel discontinuation rates in ST patients and matched controls were used to calculate the absolute incidence of ST after early clopidogrel discontinuation.

RESULTS

The overall rate of ST after cessation of clopidogrel was 4.6% (95%CI: 3.9-5.4%), as compared to 1.7% (95%CI: 1.5-1.9%) in patients who did not discontinue clopidogrel. The incidence of ST was 35.4% when clopidogrel was discontinued in the first 30 days after index-PCI declining to 11.7% when clopidogrel was discontinued in the first 180 days.

CONCLUSIONS

This dedicated ST registry shows that ST rates were very high when clopidogrel was discontinued before 6 months after index-PCI and therefore suggests that clopidogrel discontinuation in the first 6 months after ACS should be avoided.

Selection of Stent Type in Patients With Atrial Fibrillation Presenting With Acute Myocardial Infarction: An Analysis From the ACTION (Acute Coronary Treatment and Intervention Outcomes Network) Registry-Get With the Guidelines

BACKGROUND

Patients receiving oral anticoagulation in addition to dual-antiplatelet therapy are known to be at high risk for bleeding events; thus, the selection of a drug-eluting stent (DES) versus a bare metal stent (BMS) can have important implications for patients with atrial fibrillation (AF) presenting with acute myocardial infarction (MI).

METHODS AND RESULTS

From the National Cardiovascular Data Registry ACTION (Acute Coronary Treatment and Intervention Outcomes Network) Registry-Get With the Guidelines, we identified 14 427 AF patients presenting with acute MI undergoing percutaneous coronary intervention from 2008 to 2014. Temporal trends and hospital variation in DES use were examined, as were patterns of use by stroke risk (CHA2DS2-VASc) and bleeding risk ATRIA (Anticoagulation and Risk Factors in Atrial Fibrillation). Among patients with linked Medicare data (n=2844), multivariable Cox regression modeling was used to compare risks for a composite outcome (all-cause mortality, readmission for stroke, or MI), readmission for stroke, revascularization, and major bleeding at 1 year. A DES was used in 8414 (58.9%) MI patients with AF, increasing from 47.1% in 2008 to 67.9% in 2014, with wide variation among hospitals. DES placement was more common than BMS placement among patients at high stroke risk (CHA2DS2-VASc ≥2) and high bleeding risk (ATRIA ≥4). Although aspirin and a P2Y12 inhibitor were prescribed for >95% of all patients regardless of stent type at discharge, warfarin was prescribed less frequently among patients receiving a DES than a BMS (31% versus 39%, P<0.001). The composite outcome was similar between patients with a DES or BMS at 1 year (22% versus 26%; adjusted hazard ratio: 0.88; 95% confidence interval [CI], 0.76-1.03).

CONCLUSIONS

Use of DESs among MI patients with AF has increased over time, but substantial hospital-level variation was observed. Patients with AF meeting indications for anticoagulation are more likely to receive a DES than a BMS, even among those at high predicted risk of both stroke and bleeding.

Update on antithrombotic therapy after percutaneous coronary revascularisation

For relief of coronary obstruction, percutaneous coronary intervention has become a standard-of-care procedure over the past 40 years. Nonetheless, optimal outcomes after coronary stenting require careful attention to antithrombotic therapy. This review aims to summarise the current available evidence and discusses how to integrate scientific knowledge into clinical decisions. In recent years, improvement and modifications of drugs and devices have changed the field tremendously, and substantially benefitted patient outcomes. The key challenge of how to provide optimal protection against thrombotic events without excessive increases in bleeding risk has remained the same for decades. Alternative strategies with new drugs, both antiplatelet and anticoagulant agents, and new coronary stents will continue the journey to achieve this ultimate goal.

Individualizing dual antiplatelet therapy duration after percutaneous coronary intervention: from randomized control trials to personalized medicine

INTRODUCTION

Improved stent technologies have lead to reduced minimum durations of dual antiplatelet therapy (DAPT) to prevent stent thrombosis. However, the anti-ischemic benefits seen in extended DAPT in both stent and non-stent related lesions have called into question the optimum duration of DAPT after stent placement. Areas covered: We review the evidence for varying durations of DAPT after drug eluting stent placement including for patients on oral anticoagulation; decision tools available for clinicians to optimize patient selection for extended therapy and insight into application of these risk assessment tools in clinical practice. Expert commentary: The use of risk assessment tools in optimizing DAPT duration after stent placement provides an opportunity for improved outcomes by means of a personalized approach to care while allowing clinicians to engage with patients in shared-decision making.

Duration of dual antiplatelet therapy following drug-eluting stent implantation: A systemic review and meta-analysis of randomized controlled trials with longer follow up

OBJECTIVE

To evaluate the long term efficacy and safety of long duration DAPT (L-DAPT) compared to short duration DAPT (S-DAPT) after drug-eluting stent (DES) implantation.

METHODS

We searched Medline, Embase, and Cochrane Central Register of Controlled Trials (CENTRAL) to identify randomized controlled trials (RCTs) assessing the clinical impact of L-DAPT versus S-DAPT after DES and have mean follow up period of at least 2 years or longer. Primary end point was stent thrombosis (ST). Secondary endpoints were all-cause mortality, cardiac mortality, myocardial infarction (MI), target vessel revascularization (TVR), thrombolysis in myocardial infarction (TIMI) major bleeding and stroke. Event rates were compared using a random effects model.

RESULTS

We identified five RCTs in which 19,760 patients were randomized to S-DAPT (N = 9,810) and L-DAPT (n = 9,950), respectively. Compared with L-DAPT, S-DAPT was associated with higher rate of MI (odds ratio [OR] 1.48, 95% confidence interval [CI] [1.04, 2.10]). There were no significant differences between S-DAPT and L-DAPT in terms of all cause mortality, cardiac mortality, ST, TVR or stroke (OR 0.90, 95% CI [0.73, 1.12]; OR 1.02, 95% CI [0.80, 1.30]; OR 1.59, 95% CI [0.77, 3.27]; OR 0.87 95% CI [0.67, 1.14]; and OR 1.08 95% CI [0.81, 1.46], respectively). However, rate of TIMI major bleeding was significantly lower with S-DAPT compared to L-DAPT (OR 0.64, 95% CI [0.41, 0.99]).

CONCLUSIONS

In the present analysis of RCTs with longer follow up (2 years or longer), S-DAPT compared with L-DAPT, was associated with higher rate of MI and lower rate of major bleeding without any significant difference in the rates of all cause mortality, cardiac mortality, ST, TVR, and stroke.

Duration of dual anti-platelet therapy - State of the art after the DAPT and PEGASUS-TIMI 54 trials

Dual anti-platelet therapy is prescribed in the setting of coronary heart disease for the prevention of stent thrombosis and acute thrombotic events. The optimal duration of dual anti-platelet therapy is still under debate as numerous trials have shown non-inferiority of a strategy of early cessation of one of the agents as compared to the standard practice whereas two larger trials have demonstrated benefit of prolonging dual anti-platelet therapy.

A prospective, randomized, open-label trial of 6-month versus 12-month dual antiplatelet therapy after drug-eluting stent implantation in ST-elevation myocardial infarction: Rationale and design of the "DAPT-STEMI trial"

BACKGROUND

The optimal duration of dual antiplatelet therapy (DAPT) after percutaneous coronary intervention with second-generation drug eluting stents (DESs) is unclear. Because prolonged DAPT is associated with higher bleeding risk and health care costs, establishing optimal DAPT duration is of paramount importance. No other randomized controlled trials have evaluated the safety of shorter DAPT duration in ST-elevation myocardial infarction (STEMI) patients treated with second-generation DESs and latest P2Y12 platelet receptor inhibitors.

HYPOTHESIS

Six months of DAPT after Resolute Integrity stent implantation in STEMI patients is not inferior to 12 months of DAPT in clinical outcomes.

STUDY DESIGN

The Dual Antiplatelet Therapy After Drug-Eluting Stent Implantation In ST-elevation Myocardial Infarction (DAPT-STEMI) trial is a randomized, multicenter, international, open-label trial designed to examine the safety (noninferiority) of 6-month DAPT after Resolute Integrity stent implantation in STEMI patients compared with 12-month DAPT. Event-free patients on DAPT at 6month will be randomized (1:1 fashion) between single (aspirin only) versus DAPT for an additional 6 months and followed until 2 years after primary percutaneous coronary intervention. The primary end point is a patient-oriented composite endpoint of all-cause mortality, any myocardial infarction, any revascularization, stroke, and major bleeding (net adverse clinical events [NACE]) at 18 months after randomization. To achieve a power of 85% for a noninferiority limit of 1.66, a total of 1100 enrolled patients are required.

SUMMARY

The DAPT-STEMI trial aims to assess in STEMI patients treated with second-generation DESs whether discontinuation of DAPT after 6 months of event-free survival is noninferior to routine 12-month DAPT.

Duration of Dual Antiplatelet Therapy in Coronary Artery Disease: a Review Article

Dual antiplatelet therapy (DAPT) following an acute coronary syndrome or after placement of a coronary artery stent is superior to aspirin alone for prevention of atherothrombotic events but carries an increased bleeding risk. DAPT should be continued for at least 12 months based on current guidelines. Recent randomized trials demonstrate reduced ischemic events including myocardial infarction (MI), stroke, and death with continued DAPT for up to 30 months or longer, particularly in the post-MI population. However, this clinical benefit is accompanied by an increased risk of bleeding. Additional trials show mixed safety and efficacy with duration of DAPT of less than 12 months. The current data emphasizes the need to individualize DAPT duration at the patient level to balance the clinical benefits of a reduced risk of cardiovascular ischemic events with the greater risk of clinically significant bleeding. Patients at an increased risk of ischemic events and a lower risk of bleeding should be strongly considered for prolonged DAPT beyond the 1 year currently recommended in the practice guidelines.

Duration of dual antiplatelet therapy in patients treated with percutaneous coronary intervention for coronary chronic total occlusion

Background

The duration of dual antiplatelet therapy (DAPT) after drug-eluting stent implantation in coronary chronic total occlusion (CTO) remains unclear.

Methods

We retrospectively analyzed a total of 512 patients treated with percutaneous coronary intervention (PCI) in the Samsung Medical Center CTO registry. Patients were separated into ≤ 12-month (199, 38.9%) vs. > 12 month (313, 61.1%) based on DAPT duration with aspirin and clopidogrel. The primary outcome was major adverse cardiac and cerebrovascular event (MACCE) during follow-up.

Results

Median follow-up duration was 67 (interquartile range: 51–84) months. MACCE occurred in 43 patients (21.6%) in the ≤ 12-month and 55 patients (17.6%) in the > 12-month groups. In the propensity-matched population, the rate of MACCE did not differ significantly between the ≤ 12-month and > 12-month group (19.4% vs. 18.8%; hazard ratio [HR], 0.95; 95% confidential interval [CI], 0.52–1.76, p = 0.88). Moreover, moderate or severe bleeding according to BARC criteria (type 2, 3 or 5) was also similar between the ≤ 12-month and > 12-month group (2.5% vs. 1.9%; HR, 1.00; 95% CI, 0.20–4.96, p = 0.99).

Conclusion

Among patients treated with PCI for CTO, DAPT with durations of ≤ 12-month showed similar long-term clinical outcomes compared to > 12-month DAPT.

A risk scoring system to predict coronary stent thrombosis

OBJECTIVE

Stent thrombosis (ST) is a potentially life-threatening complication of percutaneous coronary intervention (PCI). We aimed to develop a scoring system to predict the risk of ST following PCI.

RESEARCH DESIGN AND METHODS

Odds ratios (ORs) for risk factors associated with ST were identified from a meta-analysis based on a systematic literature review, and through consensus expert opinion (Delphi-RAND method). The combined ORs were used to calculate risk scores for acute (within 24 hours), early (within 30 days) and late (31 days to 1 year) ST. Risk scores were validated against patient-level data from the TRITON-TIMI 38 study. Twenty risk factors were identified.

RESULTS

The most highly predictive factor for early and late ST was "incomplete duration of dual antiplatelet therapy". Derived total risk scores ranged from 0 to 22 for acute and early ST, and from 0 to 20 for late ST. Increasing scores were associated with an increasing risk of ST when applied to trial data. Model discrimination was 0.60 (p = .0028), 0.67 (p < .0001) and 0.66 (p < .0001) for acute, early and late ST respectively, indicating good discriminatory power for predicting ST. Key limitations included a lack of published data on acute ST, resulting in a risk score for this time point being based predominantly on expert opinion, and that it was not possible to map all risk factors to variables collected in the TRITON-TIMI 38 study.

CONCLUSION

Our weighted scoring system may help to stratify ST risk and individualize antiplatelet therapy in patients undergoing PCI.

Perioperative Management of Dual-Antiplatelet Therapy in Patients With New-Generation Drug-Eluting Metallic Stents and Bioresorbable Vascular Scaffolds Undergoing Elective Noncardiac Surgery

Dual-antiplatelet therapy (DAPT) is considered mandatory after new-generation drug-eluting coronary stent implantation to reduce ischemic complications such as stent thrombosis, but the need for DAPT makes the timing of elective surgery difficult. Interrupting DAPT places patients at risk for stent thrombosis, and surgery in the setting of DAPT may lead to bleeding. The 2016 American College of Cardiology/American Heart Association guideline recommends delaying elective noncardiac surgery for a minimum 6-month period to reduce ischemic risks after the implantation of a second-generation metallic drug-eluting stent (DES). However, the guideline fails to appropriately stratify surgical patients based on the indication for second-generation metallic DES implantation and other patient characteristics. The Absorb bioresorbable vascular scaffold (Abbott Vascular, Abbott Park, IL), which has a higher propensity for stent thrombosis compared with second-generation metallic DES, also produces DAPT management challenges in patients presenting for elective noncardiac surgery. Due to the novelty of bioresorbable vascular scaffold therapy, there are no guidelines available for the management of patients undergoing elective noncardiac surgery. This review addresses DAPT management in patients undergoing noncardiac surgery less than 12 months after new-generation metallic DES or bioresorbable vascular scaffold implantation and provides further guidance for anesthesiologists who encounter these challenging cases.

Bleeding-Related Deaths in Relation to the Duration of Dual-Antiplatelet Therapy After Coronary Stenting

BACKGROUND

Although some randomized controlled trials (RCTs) and meta-analyses have suggested that prolonged dual-antiplatelet therapy (DAPT) may be associated with increased mortality, the mechanistic underpinnings of this association remain unclear.

OBJECTIVES

The aim of this study was to analyze the associations among bleeding, mortality, and DAPT duration after drug-eluting stent implantation in a meta-analysis of RCTs.

METHODS

RCTs comparing different DAPT durations after drug-eluting stent placement were sought through the MEDLINE, Embase, and Cochrane databases and the proceedings of international meetings. Deaths were considered possibly bleeding related if occurring within 1 year of the episodes of bleeding. Primary analysis was by intention-to-treat. Secondary analysis was performed in a modified intention-to-treat population in which events occurring when all patients were on DAPT were excluded.

RESULTS

Individual patient data were obtained for 6 RCTs, and aggregate data were available for 12 RCTs. Patients with bleeding had significantly higher rates of mortality compared with those without, and in a time-adjusted multivariate analysis, bleeding was an independent predictor of mortality occurring within 1 year of the bleeding episode (hazard ratio: 6.93; 95% confidence interval: 4.53 to 10.60; p < 0.0001). Shorter DAPT was associated with lower rates of all-cause death compared with longer DAPT (hazard ratio: 0.85; 95% confidence interval: 0.73 to 1.00; p = 0.05), which was driven by lower rates of bleeding-related deaths with shorter DAPT compared with prolonged DAPT (hazard ratio: 0.65; 95% confidence interval: 0.43 to 0.99; p = 0.04). Mortality unrelated to bleeding was comparable between the 2 groups. Similar results were apparent in the modified intention-to-treat population.

CONCLUSIONS

Bleeding was strongly associated with the occurrence of mortality within 1 year after the bleeding event. Shorter compared with longer DAPT was associated with lower risk for bleeding-related death, a finding that may underlie the lower all-cause mortality with shorter DAPT in the RCTs of different DAPT durations after DES.

Three, six, or twelve months of dual antiplatelet therapy after DES implantation in patients with or without acute coronary syndromes: an individual patient data pairwise and network meta-analysis of six randomized trials and 11 473 patients

AIM

We sought to determine whether the optimal dual antiplatelet therapy (DAPT) duration after drug-eluting stent (DES) placement varies according to clinical presentation.

METHODS AND RESULTS

We performed an individual patient data pairwise and network meta-analysis comparing short-term (≤6-months) versus long-term (1-year) DAPT as well as 3-month vs. 6-month vs 1-year DAPT. The primary study outcome was the 1-year composite risk of myocardial infarction (MI) or definite/probable stent thrombosis (ST). Six trials were included in which DAPT after DES consisted of aspirin and clopidogrel. Among 11 473 randomized patients 6714 (58.5%) had stable CAD and 4758 (41.5%) presented with acute coronary syndrome (ACS), the majority of whom (67.0%) had unstable angina. In ACS patients, ≤6-month DAPT was associated with non-significantly higher 1-year rates of MI or ST compared with 1-year DAPT (Hazard Ratio (HR) 1.48, 95% Confidence interval (CI) 0.98-2.22; P = 0.059), whereas in stable patients rates of MI and ST were similar between the two DAPT strategies (HR 0.93, 95%CI 0.65-1.35; P = 0.71; Pinteraction = 0.09). By network meta-analysis, 3-month DAPT, but not 6-month DAPT, was associated with higher rates of MI or ST in ACS, whereas no significant differences were apparent in stable patients. Short DAPT was associated with lower rates of major bleeding compared with 1-year DAPT, irrespective of clinical presentation. All-cause mortality was not significantly different with short vs. long DAPT in both patients with stable CAD and ACS.

CONCLUSIONS

Optimal DAPT duration after DES differs according to clinical presentation. In the present meta-analysis, despite the fact that most enrolled ACS patients were relatively low risk, 3-month DAPT was associated with increased ischaemic risk, whereas 3-month DAPT appeared safe in stable CAD. Prolonged DAPT increases bleeding regardless of clinical presentation. Further study is required to identify the optimal duration of DAPT after DES in individual patients based on their relative ischaemic and bleeding risks.

Duration of dual antiplatelet therapy in acute coronary syndrome

Despite a large volume of evidence supporting the use of dual antiplatelet therapy in patients with acute coronary syndrome, there remains major uncertainty regarding the optimal duration of therapy. Clinical trials have varied markedly in the duration of therapy, both across and within trials. Recent systematic reviews and meta-analyses suggest that shorter durations of dual antiplatelet therapy are superior because the avoidance of atherothrombotic events is counterbalanced by the greater risks of excess major bleeding with apparent increases in all-cause mortality with longer durations. These findings did not show significant heterogeneity according to whether patients had stable or unstable coronary heart disease. Moreover, the potential hazards and benefits may differ when applied to the general broad population of patients encountered in everyday clinical practice who have markedly higher bleeding and atherothrombotic event rates. Clinicians lack definitive information regarding the duration of therapy in patients with acute coronary syndrome and risk scores do not appear to be sufficiently robust to address these concerns. We believe that there is a pressing need to undertake a broad inclusive safety trial of shorter durations of therapy in real world populations of patients with acute coronary syndrome. The clinical evidence would further inform future research into strategies for personalised medicine.

Optimal duration of dual anti-platelet therapy after percutaneous coronary intervention: 2016 consensus position of the Italian Society of Cardiology

Definition of the optimal duration of dual anti-platelet therapy (DAPT) is an important clinical issue, given the large number of patients having percutaneous coronary intervention (PCI), the costs and risks of pharmacologic therapy, the consequences of stent thrombosis, and the potential benefits of DAPT in preventing ischaemic outcomes beyond stent thrombosis. Nowadays, the rationale for a prolonged duration of DAPT should be not only the prevention of stent thrombosis, but also the prevention of ischaemic events unrelated to the coronary stenosis treated with index PCI. A higher predisposition to athero-thrombosis may persist for years after an acute myocardial infarction, and even stable patients with a history of prior myocardial infarction are at high risk for major adverse cardiovascular events. Recently, results of pre-specified post-hoc analyses of randomized clinical trials, including the PEGASUS-TIMI 54 trial, have shed light on strategies of DAPT in various clinical situations, and should impact the next rounds of international guidelines, and also routine practice. Accordingly, the 2015 to 2016 the Board of the Italian Society of Cardiology addressed newer recommendations on duration of DAPT based on most recent scientific information. The document states that physicians should decide duration of DAPT on an individual basis, taking into account ischaemic and bleeding risks of any given patient. Indeed, current controversy surrounding optimal duration of DAPT clearly reflects the fact that, nowadays, a one size fits all strategy cannot be reliably applied to patients treated with PCI. Indeed, patients usually have factors for both increased ischaemic and bleeding risks that must be carefully evaluated to assess the benefit/risk ratio of prolonged DAPT. Personalized management of DAPT must be seen as a dynamic prescription with regular re-evaluations of the risk/benefit to the patient according to changes in his/her clinical profile. Also, in order to derive more benefit than harm from new treatments, a multi-parametric approach using several risk scores of the ischaemic and bleeding risks might improve the process of risk factor characterization. In patients with high ischaemic risk, particularly those with a history of myocardial infarction, the benefits of extended DAPT (particularly with ticagrelor up to 3 years) are likely to outweigh the risks.

The optimal discontinuation of dual antiplatelet therapy in patients undergoing percutaneous coronary intervention with drug-eluting stents: A meta-analysis of randomized trials

BACKGROUND

Current guidelines recommend prolonged dual antiplatelet therapy (DAPT) for patients with drug-eluting stents (DES) implantation. Nevertheless, optimal discontinuation of DAPT remains a controversy. We performed a meta-analysis of all randomized controlled trials (RCTs) that evaluate optimal discontinuation of DAPT in patients undergoing percutaneous coronary intervention (PCI) with DES.

METHODS

We searched electronic databases including PubMed, Cochrane Library, EMBASE and ClinicalTrials.gov from database RCTs that reported different modes of discontinuation of DAPT in patients with DES. The primary endpoints were all-cause death, cardiovascular death, myocardial infarction (MI) and probably or definite stent thrombosis (ST). Secondary endpoints were repeat revascularization, stroke, major bleeding and net adverse clinical events (NACE).

RESULTS

We included 13 RCTs meeting the criteria with a total of 36,749 patients. No significant difference was observed in all-cause death (RR [95% CI]=0.87 [0.75, 1.01], P=0.07, I²=0%), cardiovascular death (RR [95% CI]=0.97 [0.79, 1.19], P=0.76, I²=0%), repeat revascularization (RR [95% CI]=1.07 [0.92, 1.25], P=0.36, I²=0%), and stroke (RR [95% CI]=1.01 [0.80, 1.28], P=0.94, I²=0%). Compared with shorter DAPT, longer DAPT was associated with a significant reduction in MI (RR [95% CI]=1.46 [1.26, 1.69], P<0.00001, I²=28%) and ST (RR [95% CI]=1.93 [1.45, 2.58], P<0.00001, I²=32%), and a significant increase in major bleeding (RR [95% CI]=0.60 [0.49, 0.74], P<0.00001, I²=0%). However, there was no difference in NACE (RR [95% CI]=1.03 [0.91, 1.17], P=0.63, I²=0%). In subgroup analyses based on stent type, we demonstrated that longer DAPT was associated with a significant reduction in thrombotic events (MI and ST) after first-generation DES implantation (RR [95% CI]=2.58 [1.85, 3.58], I²=0%) and everolimus-eluting stents (EES, RR [95% CI]=1.54 [1.12, 2.11], I²=0%). Conversely, there was no difference in thrombotic events in patients with zotarolimus-eluting stents (ZES, RR [95% CI]=1.17 [0.83, 1.63], I²=75%) and biodegradable polymer DES (BP-DES, RR [95% CI]=1.15 [0.74, 1.79]).

CONCLUSIONS

1) Compared with shorter DAPT, longer DAPT was associated with a significant reduction in thrombotic events (MI and ST) and a higher rate of major bleeding. 2) By the assessment of the trade-off between thrombotic and hemorrhagic events, shorter DAPT was non-inferior to longer DAPT. 3) The benefit of longer DAPT was significant in patients with first-generation DES and EES and weakened with other second-generation DES (ZES and BP-DES).

What is the optimal duration of dual antiplatelet therapy after percutaneous coronary intervention with drug-eluting stent implantation?

PURPOSE

Published evidence on varying durations of dual antiplatelet therapy (DAPT) after percutaneous coronary intervention (PCI) with implantation of a drug-eluting stent (DES) is reviewed.

SUMMARY

A systematic literature search identified 13 randomized controlled trials and eight meta-analyses evaluating patient outcomes of standard (12-month) versus shorter or longer courses of DAPT (aspirin and a P2Y12 inhibitor, usually clopidogrel) after PCI with DES implantation. Evaluated outcomes included cardiovascular (CV) events, stent thrombosis, bleeding events, and mortality. Overall, the available evidence indicates that DAPT for periods of 3-6 months was as effective as DAPT courses of 12 months or more in reducing rates of CV events and stent thrombosis and was associated with similar or lower rates of bleeding; however, the quality of that evidence was limited by methodological shortcomings, including open-label study designs and low overall event rates. Relative to 12-month DAPT, DAPT for longer periods (up to four years) was associated with decreased rates of CV events and stent thrombosis (the reduction in thrombosis risk was greatest in patients who received a first-generation DES) but also increased bleeding events; all-cause mortality appears to be similar or potentially higher with extended-duration DAPT.

CONCLUSION

DAPT for a period of 12 months should continue to be the standard recommendation after PCI with DES implantation. Routine use of shorter- or longer-duration DAPT should be discouraged; if such therapy is considered, prescribing decisions should be based on individual patient risk factors.

Single or dual antiplatelet therapy after PCI

The optimal duration and type of antiplatelet therapy after implantation of a drug-eluting stent (DES) remains uncertain. At the time of the first-in-man implantation of the sirolimus DES in 1999, the protocol-defined dual antiplatelet therapy (DAPT) duration was only 2 months. Subsequently, DAPT duration was extended to 1 year on the basis of anecdotal historical data, and this practice was then incorporated into clinical guidelines. For >1 decade, trialists have sought to compare the safety and efficacy of abbreviated (<6 months) and prolonged (>12 months) DAPT regimens. However, the body of evidence is limited by the heterogeneity of end points, time of randomization, and bleeding criteria used in each trial. Pharmaceutical advances led to the introduction of new ADP-receptor antagonists, which are thought to be more effective than clopidogrel. The ADP-receptor antagonists moved the focus from the optimal duration of DAPT to the potential efficacy of single antiplatelet therapy after DES implantation. In this Review, we summarize the current evidence on the duration of DAPT and the risk of bleeding and adverse cardiac events after DES implantation, and describe the pitfalls of trial interpretation. The ongoing, prospective trials to test single antiplatelet therapy after DES implantation are also discussed.

Dual Antiplatelet Therapy and Clinical Outcomes after Coronary Drug-Eluting Stent Implantation in Patients on Hemodialysis

BACKGROUND AND OBJECTIVES

We aimed to investigate the benefits and risks of dual antiplatelet therapy (DAPT) after coronary drug-eluting stent (DES) implantation in patients undergoing hemodialysis.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

A nested case-control analysis of patients on hemodialysis after receipt of DES and DAPT treatment was conducted using data from Taiwan's National Health Insurance Research Database for the period 2007-2011. Cases of myocardial infarction or death within 1 year after DES implantation were matched one-to-one with control patients. Odds ratios were calculated to compare DAPT continuation with discontinuation. Additionally, a propensity score-adjusted 6-month landmark cohort analysis was also conducted to evaluate the long-term benefits and risks of prolonged (>6 months) compared with ≤6 months of DAPT use. The primary outcomes were death and myocardial infarction. The secondary outcomes were ischemic stroke, revascularization, and major bleeding.

RESULTS

In the nested case-control analysis, patients who continued DAPT had a lower rate of death or myocardial infarction within 1 year after receipt of a DES (adjusted odds ratio, 0.54; 95% confidence interval, 0.36 to 0.81; P=0.003), whereas this association became statistically nonsignificant when compared with patients who discontinued DAPT for the period between 6 and 12 months after receipt of a DES (adjusted odds ratio, 1.51; 95% confidence interval, 0.75 to 3.04). In the propensity score-adjusted cohort analysis, >6 months of DAPT use was not associated with different primary or secondary outcomes than shorter-term use.

CONCLUSIONS

Our findings support that the clinical effectiveness of extended DAPT in a hemodialysis population may be tempered after 6 months post-DES implantation.

Oral antiplatelet agents for the management of acute coronary syndromes: A review for nurses and allied healthcare professionals

PURPOSE

We review the use of oral antiplatelet (OAP) therapies in acute coronary syndrome (ACS) management for nurse practitioners (NPs), focusing on current guideline recommendations.

DATA SOURCES

Treatment guidelines and clinical articles from PubMed.

CONCLUSIONS

Guidelines recommend that dual antiplatelet therapy with a P2Y₁₂ inhibitor and aspirin be initiated for ACS management. The P2Y₁₂ inhibitor clopidogrel has established efficacy, but is associated with suboptimal and delayed platelet inhibition and variability in response. The newer P2Y₁₂ inhibitors prasugrel and ticagrelor have demonstrated superior efficacy outcomes versus clopidogrel. Consequently, non-ST-segment elevation ACS (NSTE-ACS) guidelines now recommend that ticagrelor be used in preference to clopidogrel for patients treated with stents or managed medically. Because of their higher potency, prasugrel and ticagrelor are associated with increased bleeding rates versus clopidogrel, but with no increased risk of severe or life-threatening bleeding. Guidelines recommend dual antiplatelet therapy be continued ≥12 months in both medically managed and stented ACS patients, and in some cases beyond this, in absence of high bleeding risk. Updated guidelines assign preference to ticagrelor over clopidogrel for maintenance therapy in patients with NSTE-ACS and ST-elevation myocardial infarction.

IMPLICATIONS FOR PRACTICE

Enhanced NP understanding of OAP agents and current guidelines could contribute to improved ACS patient management.

Short-versus long-term Dual Antiplatelet therapy after drug-eluting stent implantation in women versus men: A sex-specific patient-level pooled-analysis of six randomized trials

BACKGROUND

Whether the efficacy and safety of dual antiplatelet therapy (DAPT) are uniform between sexes is unclear. We sought to compare clinical outcomes between short- (≤6 months) versus long-term (≥1 year) DAPT after drug-eluting stent (DES) placement in women and men.

METHODS AND RESULTS

We pooled individual patient data from 6 randomized trials of DAPT (EXCELLENT, OPTIMIZE, PRODIGY, RESET, SECURITY, ITALIC PLUS). The primary outcome was 1-year risk of major adverse cardiac events (MACE). The main secondary outcome was 1-year risk of any bleeding. Out of the 11,473 randomized patients included in the pooled dataset, 3,454 (30%) were females. At 1-year follow-up, women had higher risk of MACE (3.6% vs. 2.8%; P = 0.01) but similar risk of bleeding (1.9% vs. 1.6%; P = 0.16) as compared with men. Compared with long-term DAPT, short-term DAPT was associated with similar rates of MACE in both women (HR 0.88; 95% CI 0.62-1.25) and men (HR 1.25; 95% CI 0.95-1.6; P interaction = 0.08)]. At 1-year follow-up, short-term DAPT was associated with lower rates of bleeding as compared with long-term DAPT in both women (HR 0.84; 95% CI 0.51-1.37) and men (HR 0.58; 95% CI 0.40-0.84; P-interaction = 0.25). The presence of MVD was associated with higher MACE rates in the short-term DAPT group in women (HR: 1.16; CI 0.60-2.23) and men (HR: 2.29; CI 1.22-4.29; P interaction = 0.25).

CONCLUSIONS

Short-term DAPT is associated with similar rates of MACE but lower risk of bleeding when as compared with prolonged DAPT. There was no significant difference between sexes in the population studied. © 2016 Wiley Periodicals, Inc.

Cardiac and Noncardiac Causes of Long-Term Mortality in ST-Segment–Elevation Acute Myocardial Infarction Patients Who Underwent Primary Percutaneous Coronary Intervention

Background—

In patients with ST-segment–elevation acute myocardial infarction (STEMI) who underwent primary percutaneous coronary intervention, long-term risks for cardiac and noncardiac death beyond acute phase of STEMI have not been thoroughly evaluated yet.

Methods and Results—

We identified 3942 STEMI patients who had primary percutaneous coronary intervention within 24 hours after onset between January 2005 and December 2007 in the CREDO-Kyoto AMI registry (Coronary Revascularization Demonstrating Outcome study in Kyoto Acute Myocardial Infarction) and evaluated their short-term (within 6-month) and long-term (beyond 6-month) incidences and causes of deaths. The cumulative 5-year incidence of all-cause death in the current study population was 20.4% (cardiac death, 12.2% and noncardiac death, 9.4%, respectively). The vast majority of deaths were cardiac in origin within 6-month (cardiac death, 8.0% and noncardiac death, 0.9%), whereas noncardiac death accounted for nearly two thirds of all-cause death beyond 6-month (cardiac death, 4.6% and noncardiac death, 8.5%). In the stratified analysis according to age, the proportion of noncardiac death was similar regardless of age although the absolute mortality rate was higher with increasing age. By the multivariable Cox regression models, the independent risk factors of all-cause death were advanced age, cardiogenic shock, renal dysfunction, large infarct size, and anterior wall infarction within 6 months after STEMI, and advanced age, previous heart failure, renal dysfunction, and liver cirrhosis beyond 6 months after STEMI, respectively.

Conclusions—

In STEMI patients who underwent primary percutaneous coronary intervention, the long-term risk for cardiac death was relatively low compared with that for noncardiac death, which accounted for nearly two thirds of all-cause death beyond 6 months.

Antithrombotic management in patients with percutaneous coronary intervention requiring oral anticoagulation

The dynamic evolution of therapeutic options including the use of vitamin K antagonists (VKA), non-vitamin K oral anticoagulants (NOAC), more potent antiplatelet drugs as well as new generation drug-eluting stents could lead to the view that the current recommendations on the management of patients with percutaneous coronary intervention (PCI) requiring oral anticoagulation do not keep up with the results of several clinical studies published within the last 5 years. In the present overview, we summarize the recent advances in antithrombotic management used in atrial fibrillation patients undergoing PCI for stable coronary artery disease or acute coronary syndrome (ACS). The safety and efficacy of prasugrel and ticagrelor taken with oral anticoagulants also remain to be established in randomized trials; therefore the P2Y₁₂ inhibitor clopidogrel on top of aspirin or without is now recommended to be used together with a VKA or NOAC. It is still unclear which dose of a NOAC in combination with antiplatelet agents and different stents should be used in this clinical setting and whether indeed NOAC are safer compared with VKA in such cardiovascular patients. Moreover, we discuss the use of anticoagulation in addition to antiplatelet therapy for secondary prevention in patients with ACS. To minimize bleeding risk in anticoagulated patients following PCI or ACS, the right agent should be prescribed to the right patient at the right dose and supported by regular clinical evaluation and laboratory testing, especially assessment of renal function when a NOAC is used.

Antiplatelet Management for Coronary Heart Disease: Advances and Challenges

Coronary heart disease (CHD) remains the leading cause of death in the USA. CHD accounts for 48 % of all cardiovascular mortality or approximately one of every seven deaths. Disruption of atherosclerotic plaques--usually by rupture or erosion--and superimposed thrombosis can result in acute coronary syndromes and sudden cardiac death. Silent plaque disruption may also occur and result in coronary plaque progression and ultimately the symptomatic manifestations of stable CHD. Antiplatelet agents remain the cornerstone therapy for acute thrombotic coronary syndromes and are essential for thromboprophylaxis against these events in patients with stable CHD. Antiplatelet drugs are also important adjunct therapies during percutaneous coronary intervention (PCI) as they mitigate equipment-associated thrombotic complications that are partially induced by iatrogenic plaque rupture by interventionalists during balloon angioplasty in the cardiac catheterization laboratory. Since the introduction of clopidogrel, there has been considerable development in this field with at least three novel P2Y12 antagonists approved by the Food and Drug Administration (FDA) over the past decade. Rapidly accumulating evidence is helping to guide the optimal duration of treatment with dual antiplatelet therapy after stenting, especially with the newer drug-eluting stents. More data are also emerging on the hazards and long-term safety of these agents. It is therefore prudent for clinicians to remain current on treatment options and recent advances in this area. We herein review current and emerging antiplatelet therapies and summarize their characteristics and indications of use as well as challenges and areas of ongoing research.

Outcomes of ≤6-month versus 12-month dual antiplatelet therapy after drug-eluting stent implantation: A meta-analysis and meta-regression

BACKGROUND

The benefit of ≤6-month compared with 12-month dual antiplatelet therapy (DAPT) after percutaneous coronary intervention (PCI) with drug-eluting stent (DES) placement remains controversial. We performed a meta-analysis and meta-regression of ≤6-month versus 12-month DAPT in patients undergoing PCI with DES placement.

METHODS

We conducted electronic database searches of randomized controlled trials (RCTs) comparing DAPT durations after DES placement. For studies with longer follow-up, outcomes at 12 months were identified. Odds ratios and 95% confidence intervals were computed with the Mantel-Haenszel method. Fixed-effect models were used; if heterogeneity (I) > 40 was identified, effects were obtained with random models.

RESULTS

Nine RCTs were included with total n = 19,224 patients. No significant differences were observed between ≤6-month compared with 12-month DAPT in all-cause mortality (OR 0.87; 95% confidence interval (CI): 0.69-1.11), cardiovascular (CV) mortality (OR 0.89; 95% CI: 0.66-1.21), non-CV mortality (OR 0.85; 95% 0.58-1.24), myocardial infarction (OR 1.10; 95% CI: 0.89-1.37), stroke (OR 0.97; 95% CI: 0.67-1.42), stent thrombosis (ST) (OR 1.37; 95% CI: 0.89-2.10), and target vessel revascularization (OR 0.95; 95% CI: 0.77-1.18). No significant difference in major bleeding (OR 0.72; 95% CI: 0.49-1.05) was observed, though the all-bleeding event rate was significantly lower in the ≤6-month DAPT group (OR 0.76; 95% CI: 0.59-0.96). In the meta-regression analysis, a significant association between bleeding events and non-CV mortality with 12-month DAPT was found, as well as between ST and mortality in addition to MI with ≤6-month DAPT.

CONCLUSION

DAPT for ≤6 months is associated with similar mortality and ischemic outcomes but less bleeding events compared with 12-month DAPT after PCI with DES.

Ticagrelor with aspirin or alone in high-risk patients after coronary intervention: Rationale and design of the TWILIGHT study

BACKGROUND

Dual antiplatelet therapy (DAPT) is necessary to prevent thrombosis yet increases bleeding after percutaneous coronary intervention (PCI) with drug-eluting stents (DES). Antiplatelet monotherapy with a potent P2Y₁₂ receptor antagonist may reduce bleeding while maintaining anti thrombotic efficacy compared with conventional DAPT.

METHODS

TWILIGHT is a randomized, double-blind placebo-controlled trial evaluating the comparative efficacy and safety of antiplatelet monotherapy versus DAPT in up to 9000 high-risk patients undergoing PCI with DES. Upon enrollment after successful PCI, all patients will be treated with open label low-dose aspirin (81-100 mg daily) plus ticagrelor (90 mg twice daily) for 3 months. Event-free patients will then be randomized in a double-blind fashion to low-dose aspirin versus matching placebo with continuation of open-label ticagrelor for an additional 12 months. The primary hypothesis is that a strategy of ticagrelor monotherapy will be superior with respect to the primary endpoint of bleeding academic research consortium type 2, 3 or 5, while maintaining non-inferiority for ischemic events compared with ticagrelor plus ASA.

CONCLUSIONS

TWILIGHT is the largest study to date that is specifically designed and powered to demonstrate reductions in bleeding with ticagrelor monotherapy versus ticagrelor plus ASA beyond 3 months post-procedure in a high-risk PCI population treated with DES. The trial will provide novel insights with respect to the potential role of ticagrelor monotherapy as an alternative for long-term platelet inhibition in a broad population of patients undergoing PCI with DES.

Safety of 6-month duration of dual antiplatelet therapy after percutaneous coronary intervention in patients with acute coronary syndromes: Rationale and design of the Smart Angioplasty Research Team-safety of 6-month duration of Dual Antiplatelet Therapy after percutaneous coronary intervention in patients with acute coronary syndromes (SMART-DATE) prospective multicenter randomized trial

BACKGROUND AND RATIONALE

Dual antiplatelet therapy (DAPT) is a fundamental treatment that optimizes clinical outcomes after percutaneous coronary intervention, especially in patients with acute coronary syndrome (ACS). Although current international guidelines recommend DAPT for at least 12 months after implantation of a drug-eluting stent in patients with ACS, these recommendations are not based on randomized controlled trials dedicated to ACS population.

STUDY DESIGN

The SMART-DATE trial is a prospective, multicenter, randomized, and open-label study to demonstrate the noninferiority of 6-month DAPT compared with 12 months or longer DAPT in patients with ACS undergoing percutaneous coronary intervention. A total of 2,700 patients will undergo prospective, random assignment to either of the DAPT duration groups. To minimize the bias from different stent devices, the type of stents will be randomly assigned (everolimus-eluting stents, zotarolimus-eluting stents, or biolimus A9-eluting stents). The primary end point is a composite of all-cause death, myocardial infarction, and cerebrovascular events at 18 months after the index procedure. The major secondary end points are definite/probable stent thrombosis defined by the Academic Research Consortium and bleeding defined by Bleeding Academic Research Consortium type 2-5.

CONCLUSIONS

The SMART-DATE randomized trial is the first study exploring the safety of 6-month DAPT compared with conventional 12-month or longer DAPT dedicated to patients with ACS after second-generation drug-eluting stent implantation.