Dual Antiplatelet Therapy Study Research Articles

Generalisability of trials on antithrombotic treatment intensification in patients with cardiovascular disease

ObjectiveAssessment of generalisability of guideline-informing trials on antithrombotic treatment intensification to real-world patients with cardiovascular disease (CVD).MethodsInclusion and exclusion criteria of the Cardiovascular Outcomes for People Using Anticoagulation Strategies (COMPASS),...

Bleeding and Ischemic Risk Prediction in Patients With High Bleeding Risk (an EVOLVE Short DAPT Analysis)

The EVOLVE Short DAPT study demonstrated the safety of truncated dual antiplatelet therapy (DAPT) in patients with a high bleeding risk (HBR) treated with SYNERGY stent(s) (Boston Scientific Company, Marlborough, Massachusetts). In this population, bleeding and ischemic risk prediction may further inform DAPT decisions. This post hoc analysis of the EVOLVE Short DAPT study identified predictors of ischemic and bleeding events up to 15months using Cox proportional hazard models. The predicted probabilities of bleeding were calculated using the Breslow method. Of 2,009 enrolled patients, 96.9% of the patients met at least 1 HBR criteria. At 15months, the cumulative incidences of bleeding and ischemic events were 6.3% and 6.0%, respectively. The risk of bleeding was increased in patients who received oral anticoagulants (hazard ratio [HR] 2.24, 95% confidence interval [CI] 1.50 to 3.36, p <0.001) or had peripheral vascular disease (HR 1.61, 95% CI 1.01 to 2.56, p=0.045). The risk of ischemic events was increased in patients with diabetes (HR 1.86, 95% CI 1.24 to 2.78, p <0.01) or congestive heart failure (HR 2.06, 95% CI 1.39 to 3.04, p <0.001). Renal insufficiency/failure was associated with both endpoints. There was a strong positive correlation between the predicted probability of ischemic and bleeding events (R=0.77, p <0.001). In 617 patients with a predicted bleeding risk <4%, ischemic events predominated, and the ischemic and bleeding rates were higher in patients with a predicted bleeding risk ≥4%. Within an HBR cohort, specific characteristics identify patients at a higher risk for ischemic and separately, bleeding events. Increased bleeding risk is tied to increased ischemic risk. In conclusion, standardized risk models are needed to inform DAPT decisions in patients with a higher risk. Clinical Trial Registration: NCT02605447.

Long-Term Outcomes and Duration of Dual Antiplatelet Therapy After Coronary Intervention With Second-Generation Drug-Eluting Stents: The Veterans Affairs Extended DAPT Study.

Background Recent guidelines on dual antiplatelet therapy (DAPT) duration after percutaneous coronary intervention (PCI) balance the subsequent risks of major bleeding with ischemic events. Although generally favoring shorter DAPT duration with second-generation drug-eluting stents, the effects on long-term outcomes in the wider population are uncertain. Methods and Results We tracked all patients having PCI with second-generation drug-eluting stents in the Veterans Affairs Healthcare System between 2006 and 2016 for death, myocardial infarction, stroke, and major bleeding up to 13 years. We compared these outcomes with 4 DAPT durations of 1 to 5, 6 to 9, 10 to 12, and 13 to 18 months after the index PCI using hazard ratios (HRs) and 95% CIs from Cox proportional hazards models adjusted by inverse probability weighting. A total of 40 882 subjects with PCI were followed up for a median of 4.3 (25%-75%: 2.4-6.5) years. DAPT discontinuation was rare early after PCI (5.8% at 1-5 months and 6.3% at 6-9 months) but increased (19% and 44%) >9 months. The risk of cardiovascular and noncardiovascular death was higher (HR, 2.03-3.41) with DAPT discontinuation <9 months, likely reflecting premature cessation from factors related to early death. DAPT discontinuation after 9 months following PCI was associated with lower risks of death (HR, 0.93 [95% CI, 0.88-0.99]), cardiac death (HR, 0.79 [95% CI, 0.70-0.90]), myocardial infarction (HR, 0.75 [95% CI, 0.69-0.82]), and major bleeding (HR, 0.82 [95% CI, 0.74-0.91]). Results were similar with an index PCI for an acute coronary syndrome. Conclusions Stopping DAPT after 9 months is associated with lower long-term risks of adverse ischemic and bleeding events and supports recent guidelines of shorter duration DAPT after PCI with second-generation drug-eluting stents.

Individualizing Dual Antiplatelet Therapy (DAPT) Duration Based on Bleeding Risk, Ischemic Risk, or Both: An Analysis From the DAPT Study

BackgroundGuidelines recommend individualization of dual antiplatelet therapy (DAPT) duration. Whether to guide decisions based on bleeding risk, ischemic risk or a combination is not known. AimsTo compare a bleeding prediction model, an ischemic prediction model, and the DAPT score in guiding DAPT duration. Methods11,648 patients in the DAPT Study were categorized into higher and lower risk using a bleeding model, an ischemic model, and the DAPT score. Effect of 30 vs. 12 months of DAPT on bleeding events, ischemic events, and the combination (net-adverse clinical events [NACE]) was assessed. ResultsAmong patients stratified with the bleeding model, 30 vs. 12 months of DAPT resulted in similar ischemic and bleeding event rates. With the ischemic model, however, higher risk patients had a greater reduction in ischemic events with extended duration of DAPT (difference in risk differences [DRD]: −2.6%, 95% CI: −3.9 to −1.3%; p < 0.01), and a smaller increase in bleeding (DRD: −1.0%, 95% CI: −2.1–0.0%; p = 0.04). Similarly, high DAPT score patients had a greater reduction in ischemic events with extended DAPT duration (DRD: −2.4%, 95%: CI: −3.6 to −1.1%; p < 0.01) and a smaller increase in bleeding (DRD: −1.2%, 95%: CI: −2.2–0.0%; p = 0.02). Although NACE was similar for bleeding risk groups, NACE was significantly reduced with extended DAPT in the higher ischemic risk and high DAPT score groups. ConclusionsIn this low-bleeding risk population, stratifying patients based on predicted ischemic risk and the DAPT score best discerned benefit versus harm of extended DAPT duration on ischemic events, bleeding events, and NACE. Condensed abstractDuration of dual antiplatelet therapy (DAPT) should be guided by an individualized risk assessment. Bleeding risk tools have emerged to identify patients at high bleeding risk for whom truncated DAPT therapy may be safest. In a lower bleeding risk population, however, whether DAPT duration should be guided by bleeding risk, ischemic risk, or a combination is unknown.In this analysis, implementation of a score based on ischemic risk prediction and the DAPT score (a combination of ischemic and bleeding risk) best predicted ischemic events, bleeding events, and net-adverse clinical events (NACE).

Abstract 9972: Estimation of DAPT Study Treatment Effects in Contemporary Clinical Practice: Findings from the EXTEND-DAPT Study

Introduction: Differences in patient characteristics, changes in treatment algorithms, and advances in medical technology could each influence the applicability of older randomized trial results to contemporary clinical practice. Objectives: To evaluate whether the Dual Antiplatelet Therapy (DAPT) Study population is different from a contemporary population of US patients receiving percutaneous coronary intervention (PCI), and to estimate the treatment effect of extended duration antiplatelet therapy after PCI in this more contemporary cohort. Methods: We compared characteristics of drug-eluting stent (DES)-treated patients randomized in the DAPT Study to a sample of more contemporary DES-treated patients in the NCDR CathPCI Registry from July 2016-June 2017. After linking trial and registry data, we employed inverse-odds of trial participation weighting to account for patient and procedural characteristics and estimated a contemporary “real-world” treatment effect of 30 vs. 12 months of DAPT after coronary stent procedures. Results: The US DES-treated trial cohort included 8864 DAPT Study patients and the registry cohort included 568,540 patients. Compared to the trial population, registry patients had more comorbidities and were more likely to present with myocardial infarction and receive 2nd generation DES. After reweighting trial results to represent the registry population, there was no longer a significant effect of prolonged DAPT on reducing stent thrombosis (reweighted treatment effect: -0.40, 95% CI: -0.99%, 0.15%), MACCE ( reweighted treatment effect: -0.52, 95% CI: -2.62%, 1.03%), or MI (reweighted treatment effect: -0.97%, 95% CI: -2.75%, 0.18%), but the increase in bleeding with prolonged DAPT persisted (reweighted treatment effect: 2.42%, 95% CI: 0.79%, 3.91%). Conclusions: Differences between patients and devices used in contemporary clinical practice compared with the DAPT Study may be associated with attenuation of benefits and relatively greater harms attributable to prolonged DAPT duration. These findings may limit applicability of average treatment effects from the DAPT Study in modern clinical practice.

Prognosis of Claims- Versus Trial-Based Ischemic and Bleeding Events Beyond 1 Year After Coronary Stenting.

BackgroundIt is unknown whether clinical events identified with administrative claims have similar prognosis compared with trial‐adjudicated events in cardiovascular clinical trials. We compared the prognostic significance of claims‐based end points in context of trial‐adjudicated end points in the DAPT (Dual Antiplatelet Therapy) study.Methods and ResultsWe matched 1336 patients aged ≥65 years who received percutaneous coronary intervention in the DAPT study with the CathPCI registry linked to Medicare claims. We compared death at 21 months post‐randomization using Cox proportional hazards models among patients with ischemic events (myocardial infarction or stroke) and bleeding events identified by: (1) both trial adjudication and claims; (2) trial adjudication only; and (3) claims only. A total of 47 patients (3.5%) had ischemic events identified by both trial adjudication and claims, 24 (1.8%) in trial adjudication only, 15 (1.1%) in claims only, and 1250 (93.6%) had no ischemic events, with annualized unadjusted mortality rates of 12.8, 5.5, 14.9, and 1.26 per 100 person‐years, respectively. A total of 44 patients (3.3%) had bleeding events identified with both trial adjudication and claims, 13 (1.0%) in trial adjudication only, 65 (4.9%) in claims only, and 1214 (90.9%) had no bleeding events, with annualized unadjusted mortality rates of 11.0, 16.8, 10.7, and 0.95 per 100 person‐years, respectively. Among patients with no trial‐adjudicated events, patients with events in claims only had a high subsequent adjusted mortality risk (hazard ratio (HR) ischemic events: 31.5; 95% CI, 8.9‒111.9; HR bleeding events 23.9; 95% CI, 10.7‒53.2).ConclusionsIn addition to trial‐adjudicated events, claims identified additional clinically meaningful ischemic and bleeding events that were prognostically significant for death.

ASSESSING FRAILTY-ASSOCIATED CHARACTERISTICS AND OUTCOMES IN THE DUAL ANTIPLATELET THERAPY (DAPT) STUDY USING MEDICARE CLAIMS: INSIGHTS FROM THE EXTEND-DAPT STUDY

Frailty is not routinely assessed in clinical studies. The impact of frailty on outcomes following percutaneous coronary intervention (PCI) with dual antiplatelet therapy (DAPT) is therefore uncertain. We evaluated 1326 patients age ≥65 years in the DAPT Study, a randomized trial comparing 30 vs

Interruption of Dual Antiplatelet Therapy Within Six Months After Coronary Stents (from the Dual Antiplatelet Therapy Study)

The risk of major adverse cardiac and cerebrovascular events (MACCE) in subjects who interrupt temporarily or permanently thienopyridine therapy in the first 6 months after percutaneous coronary intervention (PCI) remains uncertain. In the dual antiplatelet therapy (DAPT) study subjects were enrolled within 72 hours of PCI and treated with aspirin and a thienopyridine for 12 months before being randomized to continued thienopyridine versus placebo. This analysis focuses on the 12-month period before randomization. Thienopyridine interruptions of greater than 24 hours, occurring in the first 6 months after PCI were evaluated. The incidence of MACCE and moderate or severe bleeding occurring within 12 months after PCI were compared between subjects with and without interruptions. Among 23,002 subjects, the incidence of interruption of thienopyridine was 5.1% (n = 1,173). Compared with subjects who adhered to treatment, subjects with an interruption had a higher incidence of MACCE (6.1% vs 4.3%, p = 0.005), death (2.2% vs 1.4%, p = 0.02), myocardial infarction (3.8% vs 2.7%, p = 0.03), and bleeding (3.1% vs 2.2%, p = 0.04) at 12 months. After adjusting for baseline characteristics, interruptions were associated with MACCE (adjusted odds ratio 1.3, 95% confidence interval 1.0, 1.7, p = 0.04) and had a borderline association with subsequent bleeding (adjusted odds ratio 1.4, 95% confidence interval 1.0, 2.0, p = 0.05). In conclusion, interruption of thienopyridine in the first 6 months after PCI occurs not infrequently and is associated with an increased risk of MACCE and subsequent bleeding between the time of interruption and 12 months after PCI.

Validating the use of registries and claims data to support randomized trials: Rationale and design of the Extending Trial-Based Evaluations of Medical Therapies Using Novel Sources of Data (EXTEND) Study

Randomized controlled trials are the "gold standard" for comparing the safety and efficacy of therapies but may be limited due to high costs, lack of feasibility, and difficulty enrolling "real-world" patient populations. The Extending Trial-Based Evaluations of Medical Therapies Using Novel Sources of Data (EXTEND) Study seeks to evaluate whether data collected within procedural registries and claims databases can reproduce trial results by substituting surrogate non-trial-based variables for exposures and outcomes. Patient-level data from 2 clinical trial programs-the Dual Antiplatelet Therapy Study and the United States CoreValve Studies-will be linked to a combination of national registry, administrative claims, and health system data. The concordance between baseline and outcomes data collected within nontrial data sets and trial information, including adjudicated end point events, will be assessed. We will compare the study results obtained using these alternative data sources to those derived using trial-ascertained variables and end points using trial-adjudicated end points and covariates. Linkage of trials to registries and claims data represents an opportunity to use alternative data sources in place of and as adjuncts to randomized clinical trial data but requires further validation. The results of this research will help determine how these data sources can be used to improve our present and future understanding of new medical treatments.

Design and rationale of the Management of High Bleeding Risk Patients Post Bioresorbable Polymer Coated Stent Implantation With an Abbreviated Versus Standard DAPT Regimen (MASTER DAPT) Study

The optimal duration of antiplatelet therapy in high-bleeding risk (HBR) patients with coronary artery disease treated with newer-generation drug-eluting bioresorbable polymer-coated stents remains unclear. MASTER DAPT (clinicaltrial.govNCT03023020) is an investigator-initiated, open-label, multicenter, randomized controlled trial comparing an abbreviated versus a standard duration of antiplatelet therapy after bioresorbable polymer-coated Ultimaster (TANSEI) sirolimus-eluting stent implantation in approximately 4,300 HBR patients recruited from ≥100 interventional cardiology centers globally. After a mandatory 30-day dual-antiplatelet therapy (DAPT) run-in phase, patients are randomized to (a) a single antiplatelet regimen until study completion or up to 5 months in patients with clinically indicated oral anticoagulation (experimental 1-month DAPT group) or (b) continue DAPT for at least 5 months in patients without or 2 in patients with concomitant indication to oral anticoagulation, followed by a single antiplatelet regimen (standard antiplatelet regimen). With a final sample size of 4,300 patients, this study is powered to assess the noninferiority of the abbreviated antiplatelet regimen with respect to the net adverse clinical and major adverse cardiac and cerebral events composite end points and if satisfied for the superiority of abbreviated as compared to standard antiplatelet therapy duration in terms of major or clinically relevant nonmajor bleeding. Study end points will be adjudicated by a blinded Clinical Events Committee. The MASTER DAPT study is the first randomized controlled trial aiming at ascertaining the optimal duration of antiplatelet therapy in HBR patients treated with sirolimus-eluting bioresorbable polymer-coated stent implantation.

External Validation of the DAPT Score in a Nationwide Population

BackgroundThe dual antiplatelet therapy (DAPT) score guides decisions on DAPT duration after coronary stenting by simultaneously predicting ischemic and bleeding risk. ObjectivesThis study sought to assess the performance of the DAPT score in a nationwide real-world population. MethodsThe study used register data in Sweden (2006 to 2014) and followed 41,101 patients who had undergone 12 months of event-free DAPT, from months 12 to 30 after stenting. Risk of myocardial infarction (MI) or stent thrombosis, major adverse cardiovascular and cerebrovascular events (MACCE) (MI, stroke, and all-cause death), and fatal or major bleeding were compared according to DAPT score. ResultsThe score had a discrimination of 0.58 (95% confidence interval [CI]: 0.56 to 0.60) for MI or stent thrombosis, 0.54 (95% CI: 0.53 to 0.55) for MACCE, and 0.49 (95% CI: 0.45 to 0.53) for fatal or major bleeding. Risk of MI or stent thrombosis was significantly increased at scores of ≥3 while MACCE risk followed a J-shaped pattern and increased at scores of ≥4. Absolute differences in fatal or major bleeding risk were small between scores. Event rates of ischemic and bleeding outcomes in patients with high (≥2) and low (<2) scores differed compared to the DAPT Study from which the score was derived; fatal or major bleeding rates were approximately one-half of those in the placebo arm of the DAPT Study. ConclusionsIn a nationwide population, the DAPT score did not adequately discriminate ischemic and bleeding risk, the relationship between score and ischemic risk did not correspond to the suggested decision rule for extended DAPT, and risk of bleeding was lower compared with the DAPT Study. The score and its decision rule may not be generalizable to real-world populations.

Rationale and design of the EVOLVE Short DAPT Study to assess 3-month dual antiplatelet therapy in subjects at high risk for bleeding undergoing percutaneous coronary intervention

While extended dual antiplatelet therapy (DAPT) with aspirin and a platelet (P2Y12) inhibitor after percutaneous coronary intervention (PCI) reduces the risk of stent thrombosis (ST) and myocardial infarction (MI), it also increases bleeding. Newer generation drug-eluting stents with bioabsorbable polymer coatings may reduce thrombotic events and allow abbreviated DAPT in selected patients. The EVOLVE Short DAPT study is designed to evaluate the safety of 3-month DAPT in high bleeding risk subjects treated with the SYNERGY bioabsorbable polymer everolimus-eluting stent. EVOLVE Short DAPT is a prospective, single-arm, international study that enrolled 2009 high risk bleeding subjects (defined as age ≥75 years, chronic anticoagulation, major bleeding within 12 months, history of stroke, renal insufficiency/failure, or thrombocytopenia) who underwent PCI with the SYNERGY stent. Subjects presenting with acute MI or complex lesions were excluded. After 3 months treatment with DAPT (except those on anticoagulant in whom aspirin is optional), subjects free from stroke, MI, revascularization or ST will be eligible to discontinue P2Y12 inhibitor, but continue aspirin. Co-primary endpoints assessed between 3-15 months are: i) death/MI compared for non-inferiority with propensity-adjusted historical group receiving 12-month DAPT, and ii) definite/probable ST compared to a performance goal. The secondary endpoint is the rate of bleeding in subjects not receiving chronic anticoagulation compared for superiority against a propensity-adjusted historical control. The EVOLVE Short DAPT study will prospectively define the safety of DAPT discontinuation at 3 months in high bleeding risk patients treated with the SYNERGY stent.

Benefit and Risk of Prolonged DAPT After Coronary Stenting in Women.

Women may derive differential benefit from prolonged DAPT (dual antiplatelet therapy) after coronary stenting than men. We assessed whether the risks/benefits of prolonged DAPT differ between women and men. The DAPT study was a randomized double-blind, placebo-controlled trial comparing continued thienopyridine versus placebo beyond 12 months after coronary stenting. We compared rates of myocardial infarction, stent thrombosis, major adverse cardiovascular and cerebrovascular events, and bleeding by sex and randomized treatment. Of 11 648 patients, women (N=2925) were older, with higher prevalence of diabetes mellitus and lower rates of acute coronary syndrome than men. At 12 to 30 months, women had similar adjusted ischemic and bleeding events as men. The effects of continued thienopyridine therapy did not differ significantly by sex for stent thrombosis (women: hazard ratio [HR], 0.54; 95% confidence interval [CI], 0.22-1.36; men: HR, 0.26; 95% CI, 0.15-0.44; interaction P=0.17), myocardial infarction (women: HR, 0.75; 95% CI, 0.50-1.14; men: HR, 0.46; 95% CI, 0.36-0.60; interaction P=0.052), major adverse cardiovascular and cerebrovascular events (women: HR, 0.87; 95% CI, 0.62-1.22; men: HR, 0.70; 95% CI, 0.58-0.85; interaction P=0.26), and bleeding (women: HR, 1.45; 95% CI, 0.88-2.40; men: HR, 1.78; 95% CI, 1.28-2.49; interaction P=0.50). Women had similar late risks of ischemia and bleeding as men after coronary stent procedures. URL: https://www.clinicaltrials.gov . Unique identifier: NCT00977938.

A clinical risk score to identify patients at high risk of very late stent thrombosis.

The aim of this study was to determine predictors of very late stent thrombosis (VLST; >1 year after stenting), and to evaluate whether addition of these predictors to the dual antiplatelet therapy (DAPT) score would improve the ability to identify patients at high risk of VLST who might benefit from DAPT. VLST is a severe complication of percutaneous coronary intervention (PCI). Extended knowledge about the predictors of VLST is needed to prevent this life-threatening complication. Recent data showed a reduction in VLST after treatment with prolonged DAPT. The DAPT study developed a prediction score to identify patients after PCI who might benefit from prolonged DAPT duration. The Dutch stent thrombosis study is a multi-center case-control study. Consecutive patients with definite VLST were included between 2007 and 2014. Baseline characteristics from the index PCI were collected. Independent predictors of VLST were identified and added to the DAPT score to develop the VLST score. In total, 155 VLST cases and 155 matched controls were included. Suboptimal result of stenting, right coronary artery as target vessel, and diffuse coronary artery ectasia were independent predictors of VLST, and added to the DAPT score. The power of the VLST score to identify patients who experienced VLST was increased (AUC, 95%CI; DAPT score: 0.64, 0.57-0.70; VLST score: 0.70, 0.63-0.76, P = 0.010). Addition of newly identified independent predictors of VLST resulted in a prediction model with a higher ability to identify patients at high risk of VLST who might benefit from prolonged DAPT.

Dissemination of 2014 dual antiplatelet therapy (DAPT) trial results: a systematic review of scholarly and media attention over 7 months

ObjectiveTo explore how the results from the 2014 dual antiplatelet therapy (DAPT) trial were disseminated to the scientific community and online media.DesignA a systematic review of scholarly and public attention...

Lesion Complexity and Outcomes of Extended Dual Antiplatelet Therapy After Percutaneous Coronary Intervention

BackgroundSubjects undergoing coronary stenting with complex lesion anatomy may experience different risks and benefits with prolonged dual antiplatelet therapy. ObjectivesThe authors assessed the effect of 30 months versus 12 months of dual antiplatelet therapy (DAPT) after percutaneous coronary intervention (PCI) based on the presence or absence of anatomically-complex target lesions. MethodsIn the DAPT Study, combined myocardial infarction (MI) or stent thrombosis and moderate/severe bleeding were assessed in enrolled (n = 25,416) and randomized (n = 11,554) subjects. Complex lesions had any of the following characteristics: unprotected left main, >2 lesions/vessel, length ≥30 mm, bifurcation with side branch ≥2.5 mm, vein bypass graft, or thrombus-containing lesion. Events were evaluated according to increasing number of complexity characteristics and compared according to DAPT score. ResultsEnrolled subjects with more complex target lesions had higher rates of MI or stent thrombosis in the first 12 months after PCI (3.9% vs. 2.4%; p < 0.001). Among those who were event-free at 12 months, rates of MI or stent thrombosis between 12 and 30 months were similar between those with versus without complex anatomy (3.5% vs. 2.9%; p = 0.07). Reduction of MI or stent thrombosis with continued thienopyridine beyond 12 months versus placebo was similar for subjects with (2.5% vs. 4.5%; hazard ratio: 0.55; 95% confidence interval: 0.38 to 0.79; p = 0.001) and without (2.0% vs. 3.8%; hazard ratio: 0.52; 95% confidence interval: 0.39 to 0.69; p < 0.001) anatomic complexity (pinteraction = 0.81), as was increase in moderate/severe bleeding (pinteraction = 0.44). Among subjects with anatomic complexity, those with DAPT scores ≥2 randomized to continued thienopyridine had greater reductions in MI or stent thrombosis (3.0% vs. 6.1%; p < 0.001) compared with subjects with scores <2 (1.7% vs. 2.3%; p = 0.42; p value comparing risk differences = 0.03). ConclusionsComplex target-lesion anatomy is associated with increased ischemic events, particularly within the first year after PCI. Among those without events in the first 12 months, the benefits of extending DAPT were similar in subjects with and without complex lesions. A high DAPT score identified those experiencing the most benefit from extended treatment among patients with and without complex anatomy. (The Dual Antiplatelet Therapy Study [DAPT Study]; NCT00977938)

Short versus prolonged dual antiplatelet therapy (DAPT) duration after coronary stent implantation: A comparison between the DAPT study and 9 other trials evaluating DAPT duration.

AimsThe Dual Antiplatelet Therapy (DAPT) study demonstrated that DAPT beyond 1-year after drug-eluting stent (DES) implantation, as compared with aspirin therapy alone, significantly reduced the risk of major cardiovascular and cerebrovascular events, which was mainly driven by the large risk reduction for myocardial infarction (MI). We sought to compare the largest DAPT study with other trials evaluating DAPT durations after DES implantation.Methods and resultsBy a systematic literature search, we identified 9 trials comparing prolonged- versus short-DAPT in addition to the DAPT study. The result from the DAPT study (N = 9961) with public–private collaboration was different from the pooled result of the 9 other investigator-driven trials (N = 22174) in terms of the effect of prolonged-DAPT on MI (odds ratio [OR] 0.48 [95%CI 0.38–0.62] versus pooled OR 0.88 [95%CI 0.67–1.15]: P = 0.001 for difference), while the trends for excess risk of prolonged-DAPT relative to short-DAPT for all-cause death (OR 1.31 [95%CI 0.97–1.78] versus pooled OR 1.16 [95%CI 0.92–1.45]: P = 0.53 for difference), and bleeding (OR 1.62 [95%CI 1.21–2.17] versus pooled OR 2.08 [95%CI 1.51–2.84]: P = 0.25 for difference) were consistently seen in both the DAPT and other trials. The annual rate of MI during aspirin mono-therapy in the DAPT study was much higher than that those in the other trials (2.7% versus 0.6–1.6%).ConclusionsGiven the difference between the DAPT study and other trials, future studies should focus on certain subgroups of patients that are more or less likely to benefit from longer duration DAPT.

Formal comment to Toyota et al.: Short versus prolonged dual antiplatelet therapy (DAPT) duration after coronary stent implantation: A comparison between the DAPT study and 9 other trials evaluating DAPT duration.

Formal comment to Toyota et al.: Short versus prolonged dual antiplatelet therapy (DAPT) duration after coronary stent implantation: A comparison between the DAPT study and 9 other trials evaluating DAPT duration.

Potentially increased incidence of scaffold thrombosis in patients treated with Absorb BVS who terminated DAPT before 18 months.

The aim of this study was to investigate the impact of dual antiplatelet therapy (DAPT) termination on late and very late scaffold thrombosis (ScT) in patients treated with the Absorb bioresorbable vascular scaffold (BVS). Data from the registries of three centres were pooled (808 patients). To investigate the effect of DAPT termination on ScT after a minimum of six months, we selected a subgroup ("DAPT study cohort" with 685 patients) with known DAPT status >6 months and excluded the use of oral anticoagulants and early ScT. In this cohort, definite/probable ScT incidence for the period on DAPT was compared to ScT incidence after DAPT termination. ScT incidence was 0.83 ScT/100 py with 95% confidence interval (CI): 0.34-1.98. After DAPT termination, the incidence was higher (1.77/100 py; 95% CI: 0.66-4.72), compared to the incidence on DAPT (0.26/100 py, 95% CI: 0.04-1.86; p=0.12) and increased within the month after DAPT termination (6.57/100 py, 95% CI: 2.12-20.38; p=0.01). No very late ScT occurred in patients who continued on DAPT for a minimum of 18 months. The incidence of late and very late definite/probable ScT was acceptable. The incidence was low while on DAPT but potentially higher when DAPT was terminated before 18 months.

Extended Duration Dual Antiplatelet Therapy After Coronary Stenting Among Patients With Peripheral Arterial Disease: A Subanalysis of the Dual Antiplatelet Therapy Study

ObjectivesThis study sought to determine whether patients with peripheral arterial disease (PAD) experience different reductions in ischemic event and increases in bleeding events with extended duration dual antiplatelet therapy versus those without PAD. BackgroundPatients with PAD have increased ischemic and bleeding risks after coronary stenting. MethodsThe DAPT (Dual Antiplatelet Therapy) study randomized 11,648 patients free from ischemic and bleeding events 12 months after coronary stenting to continued thienopyridine plus aspirin therapy for an additional 18 months versus aspirin therapy alone. The effects of continued thienopyridine on myocardial infarction (MI) or stent thrombosis, major adverse cardiovascular and cerebrovascular events (death, MI, or stroke) and bleeding (GUSTO [Global Utilization of t-PA and Streptokinase for Occluded Coronary Arteries] moderate or severe) were assessed among those with versus without PAD. ResultsAmong 11,648 randomized patients, 649 (5.57%) had PAD. Between 12 and 30 months, randomized patients with PAD had higher rates of MI/stent thrombosis (6.03% vs. 2.92%; p < 0.001), major adverse cardiovascular and cerebrovascular events (11.65% vs. 4.62%; p < 0.001), and bleeding (4.86% vs. 1.74%; p < 0.001). Continued thienopyridine versus placebo was associated with consistent treatment effects for MI/stent thrombosis (with PAD, HR: 0.63; 95% CI: 0.32 to 1.22; without PAD, HR: 0.53; 95% CI: 0.42, 0.66; interaction p = 0.631), major adverse cardiovascular and cerebrovascular events (with PAD, HR: 1.06; 95% CI: 0.67 to 1.67; without PAD, HR: 0.70; 95% CI: 0.59 to 0.84; interaction p = 0.103), and bleeding (with PAD, HR, 1.82; 95% CI: 0.87 to 3.83; without PAD, HR: 1.66; 95% CI: 1.23 to 2.24; interaction p = 0.811). ConclusionsAmong patients undergoing coronary stenting, those with PAD have more ischemic and bleeding events versus those without PAD. Extended duration dual antiplatelet therapy is associated with consistent ischemic benefit and bleeding harm among patients with and without PAD.