Optimal Duration of Dual Antiplatelet Therapy After Percutaneous Coronary Intervention

Dual antiplatelet therapy (DAPT) is an essential component of treatment in patients with coronary artery disease treated with percutaneous coronary intervention (PCI). Recommendations for duration of DAPT after PCI should consider patient-specific risk, clinical presentation, stent characteristics, and procedural factors. Prolonged DAPT results in a reduction of stent thrombosis (ST) and myocardial infarction (MI) at the cost of increased bleeding. Studies of shorter-duration DAPT demonstrate similar mortality, MI, ST, and less bleeding when compared with longer DAPT duration. We review current evidence for strategies of prolonged DAPT and abbreviated DAPT following PCI.

Efficacy and safety of short-term (≤6 months) duration of dual antiplatelet therapy after drug-eluting stents: a meta-analysis of randomized controlled trials

Objective:

Optimal duration of dual antiplatelet therapy (DAPT) after drug-eluting stent (DES) implantation remains controversial. The present study is an assessment of efficacy and safety of short-term (≤6 months) DAPT after DES implantation in patients with coronary artery disease, especially in important subgroups.

Methods:

PubMed, Embase, and the Cochrane Central Register of Controlled Trials were searched for randomized, controlled trials comparing short-term and long-term (>6 months) DAPT after DES implantation. Primary efficacy outcome was stent thrombosis (ST). Primary safety outcome was major bleeding. Pooled relative risks (RRs) with 95% confidence interval (CI) were calculated using random- or fixed-effects models as appropriate.

Results:

Total of 7 trials involving 15870 patients were included in the study. Short-term DAPT significantly reduced major bleeding by 49% compared with long-term DAPT (RR 0.51; 95% CI 0.32–0.80; p=0.003) without increasing risk of ST (RR 1.28; 95% CI 0.83–1.97; p=0.266). In addition, no differences were observed in all-cause mortality, myocardial infarction (MI), cardiac mortality, or cerebrovascular accidents. Moreover, no significant difference in composite of cardiovascular events, bleeding, and mortality was found in important clinical subgroups.

Conclusion:

Short-term DAPT is associated with lower bleeding risk compared with long-term DAPT. Number of ST and MI was higher with short-term DAPT without reaching statistical significance. Comprehensive clinical judgment is necessary to weigh benefits and risks in the individual patient.

A new scoring system (DAIGA) for predicting bleeding complications in atrial fibrillation patients after drug-eluting stent implantation with triple antithrombotic therapy

BACKGROUND

No scoring system for evaluating the bleeding risk of atrial fibrillation (AF) patients after drug-eluting stent (DES) implantation with triple antithrombotic therapy (TAT) is available. We aimed to develop a new scoring system for predicting bleeding complications in AF patients after DES implantation with TAT.

METHODS AND RESULTS

Between April 2007 and April 2014, 227 AF patients undergoing DES implantation with TAT were enrolled. Bleeding incidence defined as Bleeding Academic Research Consortium criteria≥2 was investigated and predictors of bleeding complications were evaluated using multivariate analysis. Bleeding complications occurred in 58 patients (25.6%) during follow-up. Multivariate analysis revealed dual antiplatelet therapy (DAPT) continuation (OR 3.33, P=0.01), age>75 (OR 2.14, P=0.037), international normalized ratio>2.2 (OR 5.82, P<0.001), gastrointestinal ulcer history (OR 3.06, P=0.037), and anemia (OR 2.15, P=0.042) as predictors of major bleeding complications. A score was created using the weighted points proportional to the beta regression coefficient of each variable. The DAIGA score showed better predictive ability for bleeding complications than the HAS-BLED score (AUC: 0.79 vs. 0.62, P=0.0003). Bleeding incidence was well stratified: 17.8% in low-risk (scores 0-1), 55.5% in moderate-risk (2-3), and 83.0% in high-risk (4-7) patients (P<0.001).

CONCLUSIONS

This scoring system is useful for predicting bleeding complications and risk stratification of AF patients after DES implantation with TAT.

Long-term outcomes in patients with acute coronary syndromes related to prolonging dual antiplatelet therapy more than 12 months after coronary stenting

OBJECTIVES

To assess the impact of stent type on the risk of death or myocardial infarction (MI) related to dual antiplatelet therapy (DAPT) more than 12 months (prolonged DAPT) versus 12 or less months after PCI for an acute coronary syndrome (ACS).

BACKGROUND

The recent DAPT study reported lower recurrent ischemic events from prolonged DAPT in patients treated with PCI for an ACS, but was underpowered to determine the impact of stent type.

METHODS

We determined clinical outcomes after PCI for an ACS (median follow-up: DES = 26 months, BMS = 46 months) in 18,484 patients in the Veterans Affairs system treated with first generation drug-eluting stents (DES) or bare-metal stents (BMS). We used landmark analyses starting 1 year after the index PCI to assess the risk of prolonged DAPT on the primary endpoint of death or MI. Multivariable and propensity models adjusted for confounding.

RESULTS

There was a significant interaction between stent type and prolonged DAPT for death and MI (P = 0.0036), death (P = 0.054), and major bleeding (P = 0.0013). Patients treated with prolonged DAPT had lower risks of death or MI (HR = 0.71, 95% CI = 0.61, 0.82) and death (HR = 0.74, 95%CI = 0.62, 0.89) with DES, but not BMS, and higher risks of major bleeding, particularly with BMS (HR = 1.67, P < 0.001) than DES (HR = 1.24, p = 0.01).

CONCLUSIONS

Prolonging DAPT more than 12 months after PCI for ACS only associated with a lower risk of ischemic events in the 1-4 years after PCI in those receiving first generation DES. Stent type may influence the benefit of prolonged DAPT. © 2016 Wiley Periodicals, Inc.

Short term versus long term dual antiplatelet therapy after implantation of drug eluting stent in patients with or without diabetes: systematic review and meta-analysis of individual participant data from randomised trials

OBJECTIVE

 To compare clinical outcomes between short term (up to 6 months) and long term (12 months) dual antiplatelet therapy (DAPT) after placement of a drug eluting stent in patients with and without diabetes.

DESIGN

 Individual participant data meta-analysis. Cox proportional regression models stratified by trial were used to assess the impact of diabetes on outcomes.

DATA SOURCE

 Medline, Embase, and Cochrane databases and proceedings of international meetings searched for randomised controlled trials comparing durations of DAPT after placement of a drug eluting stent. Individual patient data pooled from six DAPT trials.

PRIMARY OUTCOME

 Primary study outcome was one year risk of major adverse cardiac events (MACE), defined as cardiac death, myocardial infarction, or definite/probable stent thrombosis. All analyses were conducted by intention to treat.

RESULTS

 Six trials including 11 473 randomised patients were pooled. Of these patients, 3681 (32.1%) had diabetes and 7708 (67.2%) did not (mean age 63.7 (SD 9.9) and 62.8 (SD 10.1), respectively), and in 84 (0.7%) the information was missing. Diabetes was an independent predictor of MACE (hazard ratio 2.30, 95% confidence interval 1.01 to 5.27; P=0.048 At one year follow-up, long term DAPT was not associated with a decreased risk of MACE compared with short term DAPT in patients with (1.05, 0.62 to 1.76; P=0.86) or without (0.97, 0.67 to 1.39; P=0.85) diabetes (P=0.33 for interaction). The risk of myocardial infarction did not differ between the two DAPT regimens (0.95, 0.58 to 1.54; P=0.82; for those with diabetes and 1.15, 0.68 to 1.94; P=0.60; for those without diabetes (P=0.84 for interaction). There was a lower risk of definite/probable stent thrombosis with long term DAPT among patients with (0.26, 0.09 to 0.80; P=0.02) than without (1.42, 0.68 to 2.98; P=0.35) diabetes, with positive interaction testing (P=0.04 for interaction), although the landmark analysis showed a trend towards benefit in both groups. Long term DAPT was associated with higher rates of major or minor bleeding, irrespective of diabetes (P=0.37 for interaction).

CONCLUSIONS

 Although the presence of diabetes emerged as an independent predictor of MACE after implantation of a drug eluting stent, compared with short term DAPT, long term DAPT did not reduce the risk of MACE but increased the risk of bleeding among patients with stents with and without diabetes.

New directions for pharmacotherapy in the treatment of acute coronary syndrome

INTRODUCTION

Acute coronary syndromes (ACS) are one of the leading causes of death worldwide. Several landmark trials, followed by a widespread introduction of new agents, have significantly improved ACS outcomes in recent years. However, despite the use of contemporary therapy, a substantial number of ACS patients continue to suffer from cardiovascular events. Areas covered: The aim of this review was to summarize available data on innovative drugs and pharmacological strategies that have potential to amend the current ACS therapy. We present the results of recent large clinical trials, as well as insights from ongoing phase III and phase IV studies, exploring the value of new strategies for the improvement of outcomes in ACS. Expert opinion: More potent platelet inhibition, more profound lipid reduction and possibly anti-inflammatory action are considered to have potential to further reduce the rates of adverse cardiovascular and thrombotic events in ACS patients. 'Hit fast, hit hard' approach regarding novel antiplatelet and lipid-lowering therapy seems attractive, but it has to be considered that these strategies may be associated with increased adverse events rate. Introduction of cangrelor and ezetimibe, and potentially future recognition of proprotein convertase subtilisin/kexin type 9 antibodies, are likely to alter the landscape of ACS pharmacotherapy.

Antithrombotic Approaches in Acute Coronary Syndromes: Optimizing Benefit vs Bleeding Risks

It is estimated that in the United States, each year, approximately 620,000 persons will experience an acute coronary syndrome and approximately 70% of these will have non-ST-elevation acute coronary syndrome. Cardiovascular disease still accounts for 1 of every 3 deaths in the United States, and there is an urgent need to improve the prognosis of patients presenting with acute coronary syndrome. Cardiovascular mortality and ischemic complications are common after acute coronary syndrome, and the advent of newer antithrombotic therapies has reduced ischemic complications, but at the expense of greater bleeding. The new antithrombotic agents also raise the challenge of choosing between multiple potential therapeutic combinations to minimize recurrent ischemia without a concomitant increase in bleeding, a decision that often varies according to an individual patient's relative propensity for ischemia versus hemorrhage. In this review, we will synthesize the available information to arm health care providers with the contemporary knowledge on antithrombotic therapy and individualize treatment decisions.

Clopidogrel Versus Aspirin as an Antiplatelet Monotherapy After 12-Month Dual-Antiplatelet Therapy in the Era of Drug-Eluting Stents

BACKGROUND

The use of dual-antiplatelet therapy (DAPT) exceeding 12 months may increase a bleeding risk despite a lower risk of ischemic events. There is no study to compare clinical outcomes in patients treated with a single-antiplatelet drug after DAPT in the era of drug-eluting stents (DES). We sought to investigate the efficacy and safety of clopidogrel versus aspirin monotherapy after 12-month DAPT after DES implantation using an institutional registry.

METHODS AND RESULTS

This observational study was conducted on consecutive patients receiving DES between January 2003 and December 2010. A total of 3243 patients receiving 12-month DAPT after DES implantation without adverse clinical outcomes were divided into 2 groups based on prescribed antiplatelet status: aspirin (n=2472) and clopidogrel (n=771). Clinical, angiographic, and procedural characteristics revealed more comorbidities and more complex lesions in the clopidogrel group than in the aspirin group. At 36 months after initiation of antiplatelet monotherapy, clopidogrel was associated with a reduction in risk for a composite of cardiac death, myocardial infarction, or stroke (aspirin versus clopidogrel; 3.8% versus 2.6%; hazard ratio, 0.54; 95% confidence interval, 0.32-0.92; P=0.02). The risk of cardiac death was lower with clopidogrel monotherapy than with aspirin monotherapy (1.4% versus 0.5%; hazard ratio, 0.31; 95% confidence interval, 0.11-0.93; P=0.04). Thrombolysis in myocardial infarction major bleeding occurred similarly between both groups (0.9% versus 1.3%; hazard ratio, 1.03; 95% confidence interval, 0.46-2.32; P=0.95).

CONCLUSIONS

After 12-month DAPT, clopidogrel monotherapy, when compared with aspirin monotherapy, might be associated with a reduced risk of recurrent ischemic events in patients receiving DES.

Six Versus Twelve Months Clopidogrel Therapy After Drug-Eluting Stenting in Patients With Acute Coronary Syndrome: An ISAR-SAFE Study Subgroup Analysis

In patients presenting with acute coronary syndrome (ACS) the optimal duration of dual-antiplatelet therapy after drug-eluting stent (DES) implantation remains unclear. At 6 months after intervention, patients receiving clopidogrel were randomly assigned to either a further 6-month period of placebo or clopidogrel. The primary composite endpoint was death, myocardial infarction, stent thrombosis, stroke, or major bleeding 9 months after randomization. The ISAR-SAFE trial was terminated early due to low event rates and slow recruitment. 1601/4000 (40.0%) patients presented with ACS and were randomized to 6 (n = 794) or 12 months (n = 807) clopidogrel. The primary endpoint occurred in 14 patients (1.8%) receiving 6 months of clopidogrel and 17 patients (2.2%) receiving 12 months; hazard ratio (HR) 0.83, 95% confidence interval (CI) 0.41-1.68, P = 0.60. There were 2 (0.3%) cases of stent thrombosis in each group; HR 1.00, 95% CI 0.14-7.09, P = >0.99. Major bleeding occurred in 3 patients (0.4%) receiving 6 months clopidogrel and 5 (0.6%) receiving 12 months; HR 0.60, 95% CI 0.15-2.49, P = 0.49. There was no significant difference in net clinical outcomes after DES implantation in ACS patients treated with 6 versus 12 months clopidogrel. Ischaemic and bleeding events were low beyond 6-months.

Short- versus standard-term dual antiplatelet therapy after percutaneous coronary intervention with drug-eluting stent implantation: A meta-analysis

BACKGROUND

Twelve months of dual antiplatelet therapy (DAPT) is recommended after percutaneous coronary intervention (PCI) with drug-eluting stent (DES) implantation. However, certain clinical scenarios may require premature discontinuation of therapy (e.g. urgent surgical procedure, major bleeding). The objective of this systematic review and meta-analysis was to investigate clinically relevant outcomes associated with a shorter duration of DAPT after PCI with DES implantation.

METHODS

A systematic search of Medline and Embase (inception to December 2015) was conducted. Included were randomized controlled trials that compared 6 months (or less) of DAPT (defined as acetylsalicylic acid 75-200mg daily and a P2Y12 inhibitor) to the standard of 12 months. Outcomes of interest included death (all-cause and cardiac), myocardial infarction (MI), definite/probable stent thrombosis, and bleeding (major and overall). An odds ratio (OR) and 95% confidence interval (CI) were calculated for each outcome using a random effects model.

RESULTS

Six trials (five open-label, one double-blind) were included (N=13,900). Four studies investigated 6 months of DAPT, and two studies investigated 3 months. Median follow-up was 12 months. There was no statistically significantly difference between groups regarding all-cause death (OR 0.88, 95% CI 0.64-1.20), cardiac death (OR 1.00, 95% CI 0.64-1.55), MI (OR 1.16, 95% CI 0.87-1.56), and stent thrombosis (OR 1.22, 95% CI 0.70-2.15). Both major and any bleeding were significantly decreased with shorter-term DAPT (OR 0.58, 95% CI 0.34-0.98, and OR 0.62, 95% CI 0.47-0.81, respectively).

CONCLUSIONS

Shorter duration (3-6 months) of DAPT, as compared to 12 months, was not associated with a higher risk of death, MI, or stent thrombosis, but a lower rate of major and overall bleeding.

Should a prolonged duration of dual anti-platelet therapy be recommended to patients with diabetes mellitus following percutaneous coronary intervention? A systematic review and meta-analysis of 15 studies

Background

This study aimed to compare the adverse clinical outcomes associated with a short and a prolonged duration of Dual Anti-Platelet Therapy (DAPT) in patients with Diabetes Mellitus (DM) after undergoing Percutaneous Coronary Intervention (PCI).

Methods

Medline/PubMed, EMBASE and the Cochrane library were searched for studies comparing the short and prolonged DAPT use in patients with DM. Adverse outcomes were considered as the clinical endpoints in this analysis. Odds Ratios (OR) with 95 % Confidence Intervals (CI) were used to express the pooled effect on discontinuous variables and the pooled analyses were performed with RevMan 5.3.

Results

Fifteen studies with a total number of 25,742 patients with DM were included in this current analysis which showed no significant differences in primary endpoints, net clinical outcomes, myocardial infarction and stroke with OR: 1.03, 95 % CI: 0.65–1.64; P = 0.90, OR: 0.96, 95 % CI: 0.69–1.34; P = 0.81, OR: 0.85, 95 % CI: 0.70–1.04; P = 0.12 and OR: 0.94, 95 % CI: 0.65–1.36; P = 0.75 respectively. Revascularization was also similar between these 2 groups of patients with DM. However, even if mortality favored prolonged DAPT use, with OR: 0.87, 95 % CI: 0.76–1.00; P = 0.05, the result only approached significance. Also, stent thrombosis insignificantly favored a prolonged DAPT duration with OR: 0.56, 95 % CI: 0.27–1.17; P = 0.12. Thrombolysis In Myocardial Infarction (TIMI) defined major and minor bleeding were not significantly different in these diabetic patients with OR: 0.91, 95 % CI: 0.60–1.37; P = 0.65 and OR: 1.08, 95 % CI: 0.62–1.91; P = 0.78 respectively. However, bleeding defined by the Bleeding Academic Research Consortium (BARC) classification was significantly higher with a prolonged DAPT use in these diabetic patients with OR: 1.92, 95 % CI: 1.58–2.34; P < 0.00001.

Conclusion

Following PCI, a prolonged DAPT use was associated with similar adverse clinical outcomes but with a significantly increased BARC defined bleeding compared to a short term DAPT use in these patients with DM. However, even if mortality and stent thrombosis favored a prolonged DAPT use, these outcomes only either reached statistical significance or were insignificant respectively, showing that a clear decision about recommending a prolonged duration of DAPT to patients with DM might not be possible at this moment, warranting further research in this particular subgroup.

Randomized evaluation of short-term dual antiplatelet therapy in patients with acute coronary syndrome treated with the COMBO dual therapy stent: rationale and design of the REDUCE trial

BACKGROUND

The optimal duration of dual antiplatelet therapy (DAPT) in acute coronary syndrome (ACS) patients treated with drug eluting stents (DES) is still under debate. Recent meta-analyses on ≤6months versus 12months DAPT suggest that bleeding rates can be reduced, without a higher rate of thrombotic complications. In particular, the COMBO dual therapy stent, being associated with early re-endothelialization, may allow for a reduction of the duration of DAPT without increasing the thrombotic risk, while reducing the risk of bleeding complications.

AIM

The aim of the REDUCE trial is to demonstrate the non-inferiority of a combined efficacy and safety endpoint of a short-term 3months DAPT strategy as compared to standard 12-month DAPT strategy in ACS patients treated with the COMBO stent.

DESIGN

A prospective, multicenter, randomized study designed to enroll 1500 patients with ACS treated with the COMBO stent. Patients will be randomized before discharge in a 1:1 fashion to either 3 or 12months of DAPT. A clinical follow-up is scheduled at 3, 6, 12, and 24months. The primary endpoint is the time to event as defined by the occurrence of one of the following: all cause mortality, myocardial infarction, stent thrombosis, stroke, target vessel revascularization or bleeding (Bleeding Academic Research Council type II, III and V) within 12months. The study has recruited patients since July 2014, and the results are expected in 2017.

SUMMARY

A reduction of the DAPT duration in ACS patients after PCI without affecting the thrombotic risk is an attractive option with regard to the associated bleeding risk. The REDUCE trial will be the first to investigate the efficacy and safety of a 3-month DAPT strategy compared to a 12-month DAPT strategy in an ACS only population treated with the COMBO stent.

Duration of Dual Antiplatelet Therapy After Drug-Eluting Stent Implantation in Patients With and Without Acute Coronary Syndrome: A Systematic Review of Randomized Controlled Trials

In this systemic review we evaluated the efficacy and safety of long duration dual anti-platelet therapy (DAPT) (L-DAPT) compared with short duration DAPT (S-DAPT) after drug-eluting stent (DES) implantation in patients who presented with or without acute coronary syndromes (ACS). We identified 8 randomized controlled trials in which 30,975 patients were randomized to S-DAPT versus L-DAPT (12,421 ACS and 18,554 non-ACS). Short duration dual anti-platelet therapy was associated with an increase in target vessel revascularization (TVR) in ACS patients, but the difference was not significant for non-ACS patients (odds ratio [OR] 5.04 [95% CI, 1.28-19.76], and OR, 0.89 [95% CI, 0.51-1.55], respectively). The risk of cardiac mortality was not significantly different with S-DAPT and L-DAPT for ACS (OR, 1.69 [95% CI, 0.82-3.50]) and non-ACS patients (OR, 0.89 [95% CI, 0.57-1.37]). For all cause mortality, myocardial infarction, and stent thrombosis, most of the events were derived from the DAPT study, thus a meta-analysis was not performed for these end points. Based on our review of the literature, we conclude that S-DAPT was associated with higher rates of stent thrombosis and myocardial infarction, and non-significant differences in all-cause mortality, with no significant interactions according to ACS vs non-ACS. However, in non-ACS patients, the benefit-risk profile favored S-DAPT, with lower all-cause mortality, whereas the trends were reversed in ACS. Additional studies are required to determine if the benefit-risk profile of S-DAPT vs L-DAPT varies according to clinical syndrome.

Incidence and Clinical Features of Early Stent Thrombosis in the Era of New P2y12 Inhibitors (PLATIS-2)

Early stent thrombosis (EST) (≤ 30 days after stent implantation) is a relatively rare but deleterious complication of percutaneous coronary intervention (PCI). Administration of newer P2Y12 inhibitors (prasugrel and ticagrelor) combined with aspirin has been shown to reduce the incidence of sub-acute and late stent thrombosis, compared with clopidogrel. We investigated the “real life” incidence of EST in patients from a large acute coronary syndrome (ACS) national registry, where newer P2Y12 inhibitors are widely used. Patients were derived from the ACS Israeli Survey (ACSIS), conducted during 2006, 2008, 2010 and 2013. Major adverse cardiac events (MACE) at 30days were defined as all-cause death, recurrent ACS, EST and stroke.Of the 4717 ACS patients who underwent PCI and stenting, 83% received clopidogrel and 17% newer P2Y12 inhibitors. The rate of EST was similar in both groups (1.7% in the newer P2Y12 inhibitor group vs. 1.4% in the clopidogrel-treated patients, p = 0.42). Results were consistent after multivariate analysis (adjusted HR = 1.06 [p = 0.89]). MACE occurred in 6.4% in the newer P2Y12 inhibitor group compared with 9.2% in the clopidogrel group (P<0.01). However, multivariate logistic regression modeling showed that treatment with newer P2Y12 inhibitors was not significantly associated with the secondary endpoint of MACE when compared with clopidogrel therapy [OR = 1.26 95%CI (0.93–1.73), P = 0.136]. The incidence of "real life" EST at 1month is relatively low, and appears to be similar in patients who receive newer P2Y12 inhibitors as well as in those who receive clopidogrel.

Prasugrel Use in Real Life: A Report From the Outpatient Setting in France

The objective of this study was to provide descriptive statistics on patterns of prasugrel usage in the outpatient setting in France. This retrospective study was conducted to describe treatment patterns for prasugrel in the outpatient setting in France using the Intercontinental Marketing Services (IMS) Disease Analyzer database, which collates electronic medical records updated by a nationally representative database of 1200 French general practitioners (GPs). Anonymous data were collected prospectively at each follow-up visit. The study population consisted of patients with ≥1 prescription for prasugrel in the outpatient setting from its launch date to 3 years post-launch. Patients were followed up from the date of the first prescription for prasugrel recorded in the database until they died, changed GP, or reached the end of the study, whichever came first. In France, the IMS Disease Analyzer included 1052 patients receiving ≥1 prescription of prasugrel from January 2010 until October 2012. Eighty-five percent of the population was male. The mean age was 58 years; 94.3% were age <75 years, and 95.0% weighed ≥60 kg. Of the total, 99.8% of patients were prescribed a daily maintenance dose of 10 mg, and 0.2% had a history of transient ischemic attack/stroke. Concomitant medications were antiplatelet agents (100%; aspirin, 93.7%), lipid-lowering agents (90.1%), β-blockers (83.7%), angiotensin-converting enzyme inhibitors (62.2%), and anti-ulcer medications (55.1%). The results reflect good usage of prasugrel by French GPs in the outpatient setting, with excellent implementation of the Prasugrel European Summary Product Characteristics.

Meta-Analysis of the Duration of Dual Antiplatelet Therapy in Patients Treated With Second-Generation Drug-Eluting Stents

The purpose of the study was to evaluate the optimal duration of dual antiplatelet therapy (DAPT) after percutaneous coronary intervention, especially in the era of second-generation drug-eluting stents (DES). The work was conducted from November 2014 to April 2015. All randomized controlled trials comparing short (<12 months) versus long (≥12 months) DAPT in patients treated with second-generation DES were analyzed. Sensitivity analyses were performed for length of DAPT and type of DES. All-cause death was the primary end point, whereas cardiovascular death, myocardial infarction (MI), stent thrombosis (ST), and major bleeding were secondary end points. Results were pooled and compared with random-effect models and meta-regression analysis. Eight randomized controlled trials with 18,810 randomized patients were included. The studies compared 3 versus 12 months of DAPT (2 trials), 6 versus 12 months (3 trials), 6 versus 24 months (1 trial), 12 versus 24 months (1 trial), and 12 versus 30 months (1 trial). Comparing short versus long DAPT, there were no significant differences in all-cause death (odds ratio [OR] 0.87; 95% confidence interval [CI] 0.66 to 1.44), cardiovascular death (OR 0.95; 95% CI 0.65 to 1.37), and ST (OR 1.20; 95% CI 0.79 to 1.83), and no differences were present when considering everolimus-eluting and fast-release zotarolimus-eluting stents separately. Shorter DAPT was inferior to longer DAPT in preventing MI (OR 1.35; 95% CI 1.03 to 1.77). Conversely, major bleeding was reduced by shorter DAPT (OR 0.60; 95% CI 0.42 to 0.96). Baseline features did not influence these results in meta-regression analysis. In conclusion, DAPT for ≤6 months is reasonable for patients treated with everolimus-eluting and fast-release zotarolimus-eluting stents, with the benefit of less major bleeding at the cost of increased MI, with similar survival and ST rates. An individualized patient approach to DAPT duration should take into account the competing risks of bleeding and ischemic complications after present-generation DES.

Diabetes Mellitus and Prevention of Late Myocardial Infarction After Coronary Stenting in the Randomized Dual Antiplatelet Therapy Study

Background—

Patients with diabetes mellitus (DM) are at high risk for recurrent ischemic events after coronary stenting. We assessed the effects of continued thienopyridine among patients with DM participating in the Dual Antiplatelet Therapy (DAPT) Study as a prespecified analysis.

Methods and Results—

After coronary stent placement and 12 months treatment with open-label thienopyridine plus aspirin, 11 648 patients free of ischemic or bleeding events and who were medication compliant were randomly assigned to continued thienopyridine or placebo, in addition to aspirin, for 18 more months. After randomization, patients with DM (n=3391), in comparison with patients without DM (n=8257), had increased composite outcome of death, myocardial infarction (MI), or stroke (6.8% versus 4.3%, P <0.001), increased death (2.5% versus 1.4%, P <0.001), and MI (4.2% versus 2.6%, P <0.001). Among patients with DM, in a comparison of continued thienopyridine versus placebo, rates of stent thrombosis were 0.5% versus 1.1%, P =0.06, and rates of MI were 3.5% versus 4.8%, P =0.058; and among patients without DM the rates were 0.4% versus 1.4%, P <0.001 (stent thrombosis, P interaction=0.21) and 1.6% versus 3.6%, P <0.001 (MI, P interaction=0.02). Bleeding risk with continued thienopyridine was similar among patients with or without DM (interaction P =0.61).

Conclusions—

In patients with DM, continued thienopyridine beyond 1 year after coronary stenting is associated with reduced risk of MI, although this benefit is attenuated in comparison with patients without DM.

Clinical Trial Registration—

URL: http://www.clinicaltrials.gov . Unique identifier: NCT00977938.

Dual Antiplatelet Therapy After Drug-eluting Stent Implantation

The current guidelines for percutaneous coronary intervention use recommend dual antiplatelet therapy (DAPT) with aspirin and a P2Y12 inhibitor after drug eluting stent (DES) implantation. The optimal duration of DAPT is however area of debate. Recent clinical trials and meta-analyses suggest that the choice of DAPT duration should be tailored individually, based on the balance between ischemic and bleeding risk carried by the patient.

Duration of Dual Antiplatelet Therapy: A Systematic Review for the 2016 ACC/AHA Guideline Focused Update on Duration of Dual Antiplatelet Therapy in Patients With Coronary Artery Disease: A Report of the American College of Cardiology/American Heart Association Task Force on Clinical Practice Guidelines

BACKGROUND

The optimal duration of dual antiplatelet therapy (DAPT) after implantation of newer-generation drug-eluting stents (DES) remains uncertain. Similarly, questions remain about the role of DAPT in long-term therapy of stable post-myocardial infarction (MI) patients.

AIM

Our objective was to compare the incidence of death, major hemorrhage, MI, stent thrombosis, and major adverse cardiac events in patients randomized to prolonged or short-course DAPT after implantation of newer-generation DES and in secondary prevention after MI.

METHODS

We used traditional frequentist statistical and Bayesian approaches to address the following questions: Q1) What is the minimum duration of DAPT required after DES implantation? Q2) What is the clinical benefit of prolonging DAPT up to 18 to 48 months? Q3) What is the clinical effect of DAPT in stable patients who are >1 year past an MI?

RESULTS

We reviewed evidence from 11 randomized controlled trials (RCTs) that enrolled 33 051 patients who received predominantly newer-generation DES to answer: A1) Use of DAPT for 12 months, as compared with use for 3 to 6 months, resulted in no significant differences in incidence of death (odds ratio [OR]: 1.17; 95% confidence interval [CI]: 0.85 to 1.63), major hemorrhage (OR: 1.65; 95% CI: 0.97 to 2.82), MI (OR: 0.87; 95% CI: 0.65 to 1.18), or stent thrombosis (OR: 0.87; 95% CI: 0.49 to 1.55). Bayesian models confirmed the primary analysis. A2) Use of DAPT for 18 to 48 months, compared with use for 6 to 12 months, was associated with no difference in incidence of all-cause death (OR: 1.14; 95% CI: 0.92 to 1.42) but was associated with increased major hemorrhage (OR: 1.58; 95% CI: 1.20 to 2.09), decreased MI (OR: 0.67; 95% CI: 0.47 to 0.95), and decreased stent thrombosis (OR: 0.45; 95% CI: 0.24 to 0.74). A risk-benefit analysis found 3 fewer stent thromboses (95% CI: 2 to 5) and 6 fewer MIs (95% CI: 2 to 11) but 5 more major bleeds (95% CI: 3 to 9) per 1000 patients treated with prolonged DAPT per year. Post hoc analyses provided weak evidence of increased mortality with prolonged DAPT. We reviewed evidence from 1 RCT of 21 162 patients and a post hoc analysis of 1 RCT of 15 603 patients to answer: A3): Use of DAPT >1 year after MI reduced the composite risk of cardiovascular death, MI, or stroke (hazard ratio: 0.84; 95% CI: 0.74 to 0.95) but increased major bleeding (hazard ratio: 2.32; 95% CI: 1.68 to 3.21). A meta-analysis and a post hoc analysis of an RCT in patients with stable cardiovascular disease produced similar findings.

CONCLUSIONS

The primary analysis provides moderately strong evidence that prolonged DAPT after implantation of newer-generation DES entails a tradeoff between reductions in stent thrombosis and MI and increases in major hemorrhage. Secondary analyses provide weak evidence of increased mortality with prolonged DAPT after DES implantation. In patients whose coronary thrombotic risk was defined by a prior MI rather than by DES implantation, the primary analysis provides moderately strong evidence of reduced cardiovascular events at the expense of increased bleeding.

Dual Antiplatelet Therapy Duration: A Review of Current Available Evidence

PURPOSE

Multiple regimens of antiplatelet and anticoagulation therapy have been used in the past in patients undergoing percutaneous coronary intervention (PCI). Later trials of PCI stenting demonstrated the efficacy of dual-antiplatelet therapy (DAPT) in reducing stent- and non-stent-related thrombotic events in this specific population. Nonetheless, the required duration of DAPT has not yet been elucidated. In this article we sought to identify various randomized clinical trials (RCTs), pooled analyses, meta-analyses, and data pertaining to the optimal duration of DAPT and attempt some recommendations based on patients' clinical and procedural profiles.

METHODS

We performed an extensive search using MEDLINE, Scopus, Cochrane Library, and Internet sources for abstracts, manuscripts, and conference reports without any language or date restrictions. In our review we included all available evidence from RCTs, meta-analyses, observational studies, and abstracts pertaining to our topic. Search results that were deemed irrelevant or that would not serve the goal or topic of our review were excluded.

RESULTS

Our search yielded 10 RCTs directly comparing different durations of DAPT, 3 meta-analyses amassing the evidence resulting from randomized data, and numerous observational studies that served the aim of our review. The observational studies included in the manuscript are directly related to instances in which RCTs could not be performed or introduce important concepts related to the duration of DAPT.

IMPLICATIONS

There is no conclusive evidence that determines the mandatory DAPT duration after PCI. In addition, there are distinct patient populations that need specific treatment regimens, such as diabetic patients or those on long-term oral anticoagulation. Therefore, clinical judgement and meticulous examination of all pertaining risk factors are required for each individual. These factors include those related to a patient's characteristics, treatment procedures, lesion complexity, and stent type. Currently ongoing studies are anticipated to further elucidate and integrate our understanding with regard to DAPT.

Six Versus 12 Months of Dual Antiplatelet Therapy After Implantation of Biodegradable Polymer Sirolimus-Eluting Stent

Background—

There are no reports on a large-scale randomized trial exploring optimal dual antiplatelet therapy (DAPT) duration after biodegradable polymer sirolimus-eluting stent implantation. We sought to report the outcomes of a randomized substudy of the prospective Evaluate Safety and Effectiveness of the Tivoli DES and the Firebird DES for Treatment of Coronary Revascularization (I-LOVE-IT 2) trial.

Methods and Results—

In the prospective noninferiority randomized I-LOVE-IT 2 trial, 1829 patients allocated to the biodegradable polymer sirolimus-eluting stent group were also randomized to receive either 6-month (n=909) or 12-month DAPT (n=920). The primary end points of this noninferiority substudy were 12-month target lesion failure (composite of cardiac death, target vessel myocardial infarction or clinically indicated target lesion revascularization), and the major secondary end points were 12-month net adverse clinical and cerebral events (composite of all-cause death, all myocardial infarction, stroke, or major bleeding [Bleeding Academic Research Consortium type ≥3]). The 12-month target lesion failure in 6-month DAPT group was comparable with the 12-month DAPT group (6.8% versus 5.9%; difference and 95% confidence interval, 0.87% [−1.37% to 3.11%], P for noninferiority=0.0065). Further follow-up at 18 months showed that incidence of target lesion failure and net adverse clinical and cerebral events were similar between the 2 groups (7.5% versus 6.3%, log-rank P =0.32; 7.8% versus 7.3%, log-rank P =0.60; respectively), as well as their individual end point components.

Conclusions—

This study indicated noninferiority in safety and efficacy of 6-month versus 12-month DAPT after implantation of a novel biodegradable polymer sirolimus-eluting stent.

Clinical Trial Registration—

URL: http://www.clinicaltrials.gov . Unique identifier: NCT01681381.

The Tradeoff Between Shorter and Longer Courses of Dual Antiplatelet Therapy After Implantation of Newer Generation Drug-Eluting Stents

The benefit of prolonged dual antiplatelet therapy (DAPT) after implantation of drug-eluting stents (DESs) remains uncertain. In 10 randomized controlled trials (RCTs) of 31,666 predominantly low-risk patients undergoing DES implantation, shorter courses (3-12 months) of DAPT resulted in lower mortality (odds ratio [OR] 0.83, 95 % confidence interval [CI] 0.69-0.98) and major hemorrhage (OR 0.60, 95 % CI 0.48-0.75) but increased myocardial infarction (MI, OR 1.34, 95 % CI 1.04-1.73) and stent thrombosis (ST, OR 1.75, 95 % CI 1.08-2.82) than did longer courses (12-36 months) of DAPT. A risk-benefit analysis identified 3 fewer deaths and 5 fewer bleeds but 4 more MIs and 3 more STs annually for every 1000 patients treated with the shorter courses. In the predominantly low-risk population enrolled in RCTs, limiting DAPT to 3 to 12 months after DES implantation saved lives and prevented bleeding at the expense of increased ST and MI.