Bleeding and ischaemic outcomes in patients treated with dual or triple antithrombotic therapy: systematic review and meta-analysis

Aims

The combination of oral anticoagulation with a P2Y12 inhibitor and aspirin in patients with atrial fibrillation (AF) undergoing percutaneous coronary intervention (PCI) is associated with a high bleeding risk. Dual antithrombotic therapy (DAT) with omission of aspirin is a promising option to reduce bleedings, but carries a yet unknown risk of ischaemic events. We therefore sought to systematically review and analyse randomized controlled trials investigating DAT vs. triple antithrombotic therapy (TAT) in patients with AF following PCI and/or acute coronary syndrome (ACS).

Methods and results

We included four trials with overall 9317 patients (5039 DAT, 4278 TAT) in our analysis. Dual antithrombotic therapy was associated with a significant reduction in thrombolysis in myocardial infarction major bleeding [hazard ratio (HR) 0.52, 95% confidence interval (CI) 0.42–0.65; P = 0.0001], while the composite trial-defined ischaemic endpoint did not differ significantly between DAT and TAT (HR 0.98, 95% CI 0.79–1.22; P = 0.88). There was also no difference regarding the occurrence of myocardial infarction (MI; HR 1.16, 95% CI 0.92–1.46; P = 0.21) or stent thrombosis (HR 1.25, 95% CI 0.69–2.26; P = 0.46). Absolute numbers for MI were 131/4278 (3.1%) with TAT and 182/5039 (3.6%) with DAT, and for stent thrombosis 32/4278 (0.75%) and 52/5039 (1%), respectively. A post hoc power calculation based on the size and event rate of this meta-analysis revealed 80% power to detect a 37% and 100% increase in MI and stent thrombosis, respectively.

Conclusion

Dual antithrombotic therapy significantly reduces bleedings compared with TAT and seems to have a similar effect in preventing ischaemic endpoints in AF patients post-PCI or ACS. Future investigations are needed to determine its applicability specifically in patients at high risk of ischaemic outcomes.

High Bleeding Risk Patients Treated with Very Thin-Strut Biodegradable Polymer or Thin-Strut Durable Polymer Drug-Eluting Stents in the BIO-RESORT Trial

Purpose

Patients with high bleeding risk (HBR) who undergo percutaneous coronary intervention also have an increased risk of ischemic events and represent an overall high-risk population. The coating of durable polymer drug-eluting stents (DP-DES) may induce inflammation and delay arterial healing, which might be reduced by novel biodegradable polymer DES (BP-DES). We aimed to evaluate the safety and efficacy of treating HBR patients with very thin-strut BP-DES versus thin-strut DP-DES.

Methods

Participants in BIO-RESORT (NCT01674803), an investigator-initiated multicenter, randomized all-comers trial, were treated with very thin-strut BP-DES (Synergy or Orsiro) or thin-strut DP-DES (Resolute Integrity). For the present analysis, patients were classified following HBR criteria based on previous trials. The primary endpoint was target vessel failure: a composite of cardiac death, target vessel-related myocardial infarction, or target vessel revascularization at 1 year.

Results

Of all 3514 patients, 1009 (28.7%) had HBR. HBR patients were older (p < 0.001) and had more co-morbidities than non-HBR patients (p < 0.001). At 1-year follow-up, HBR patients had significantly higher rates of target vessel failure (6.7 vs. 4.2%, p = 0.003), cardiac death (1.9 vs. 0.4%, p < 0.001), and major bleeding (3.3 vs. 1.5%, p = 0.001). Of all 1009 HBR patients, 673 (66.7%) received BP-DES and 336 (33.3%) had DP-DES. The primary endpoint was met by 43/673 (6.5%) patients treated with BP-DES and 24/336 (7.3%) treated with DP-DES (HR 0.88 [95%CI 0.54–1.46], p = 0.63). There were no significant between-group differences in the most global patient-oriented clinical endpoint (9.7 vs. 10.5%, HR 0.92 [95%CI 0.61–1.39], p = 0.69) and other secondary endpoints.

Conclusions

At 1-year follow-up, very thin-strut BP-DES showed similar safety and efficacy for treating HBR patients as thin-strut DP-DES.

Electronic supplementary material

The online version of this article (10.1007/s10557-018-6823-9) contains supplementary material, which is available to authorized users.

Vitamin D levels and platelet reactivity in diabetic patients receiving dual antiplatelet therapy

BACKGROUND

Hypovitaminosis D represents an emerging cardiovascular risk factor, and especially among higher-risk subsets of patients, such as in those with diabetes mellitus. The anti-inflammatory and anti-thrombotic properties of vitamin D, in fact, could be even more beneficial among diabetics, where platelet hyperreactivity and suboptimal response to antiplatelet drugs has been associated with poorer outcomes. However, no study has so far evaluated the impact of vitamin D levels on platelet reactivity and high-on treatment platelet reactivity (HRPR) among diabetic patients receiving dial antiplatelet therapy (DAPT).

METHODS

Our population is represented by a consecutive cohort ofdiabetic patients treated with DAPT (ASA + clopidogrel or ticagrelor or dose-adjusted prasugrel) for an acute coronary syndrome or elective PCI, undergoing platelet reactivity assessment at 30-90 days post-discharge. Aggregation was assessed by multiple-electrode aggregometry. HRPR was defined for values above the lower limit of normality (in non-treated patients).

RESULTS

We included 440 patients, that were divided according to quartiles values of vitamin D (< 9.4; 9.4-15.59; 15.6-21.64; ≥ 21.65 ng/ml). Among them, 31 were excluded as chronically treated with vitamin D supplementation. Lower vitamin D quartiles were associated with more advanced age (p = 0.01), female gender (p = 0.04), renal failure (p = 0.005), history of previous MI (p = 0.01), CABG and use of diuretics (p = 0.003), severe coronary disease (p = 0.002), but lower ejection fraction (p = 0.001), treatment with statins (p = 0.04) and new ADP-antagonists (p = 0.002). Vitamin D levels related with higher HbA1c (p = 0.001), cholesterol (p = 0.02) and creatinine (p = 0.004) and lower hemoglobin (p = 0.004). The prevalence of HRPR with ASA was low and not related to vitamin D quartiles (3.4% vs 2.7% vs 1.8% vs 2.1%, p = 0.44; adjusted OR[95%CI] = 1.16[0.60-2.26], p = 0.67). The prevalence of HRPR for ADP antagonists was associated to hypovitaminosis D (40.2% vs 29.1% vs 29.4% vs 25.5%, p = 0.03; (adjusted OR[95%CI] = 1.76[1.04-2.98], p = 0.036for I vs II-IV quartile). The impact of vitamin D quartiles, was significant only in patients on new ADP antagonists (n = 225, of whom 81 on prasugrel 5 mg; p = 0.03; adjusted OR[95%CI] = 3.12[1.34-7.49], p = 0.009) but not with clopidogrel (p = 0.85, adjusted OR[95%CI] = 1.05[0.49-2.24], p = 0.89).

CONCLUSIONS

Among diabetic patients receiving dual antiplatelet therapy for an acute coronary syndrome or elective percutaneous coronary intervention, severe vitamin D deficiency is associated with a higher ADP-mediated platelet reactivity and rate of HRPR, and especially for new ADP-antagonists over clopidogrel.

ST-segment elevation myocardial infarction

ST-segment elevation myocardial infarction (STEMI) is the most acute manifestation of coronary artery disease and is associated with great morbidity and mortality. A complete thrombotic occlusion developing from an atherosclerotic plaque in an epicardial coronary vessel is the cause of STEMI in the majority of cases. Early diagnosis and immediate reperfusion are the most effective ways to limit myocardial ischaemia and infarct size and thereby reduce the risk of post-STEMI complications and heart failure. Primary percutaneous coronary intervention (PCI) has become the preferred reperfusion strategy in patients with STEMI; if PCI cannot be performed within 120 minutes of STEMI diagnosis, fibrinolysis therapy should be administered to dissolve the occluding thrombus. The initiation of networks to provide around-the-clock cardiac catheterization availability and the generation of standard operating procedures within hospital systems have helped to reduce the time to reperfusion therapy. Together with new advances in antithrombotic therapy and preventive measures, these developments have resulted in a decrease in mortality from STEMI. However, a substantial amount of patients still experience recurrent cardiovascular events after STEMI. New insights have been gained regarding the pathophysiology of STEMI and feed into the development of new treatment strategies.

Comprehensive ascertainment of bleeding in patients prescribed different combinations of dual antiplatelet therapy (DAPT) and triple therapy (TT) in the UK: study protocol for three population-based cohort studies emulating 'target trials' (the ADAPTT Study)

INTRODUCTION

'Real world' bleeding in patients exposed to different regimens of dual antiplatelet therapy (DAPT) and triple therapy (TT, DAPT plus an anticoagulant) have a clinical and economic impact but have not been previously quantified.

METHODS AND ANALYSIS

We will use linked Clinical Practice Research Datalink (CPRD) and Hospital Episode Statistics (HES) data to assemble populations eligible for three 'target trials' in patient groups: percutaneous coronary intervention (PCI); coronary artery bypass grafting (CABG); conservatively managed (medication only) acute coronary syndrome (ACS). Patients ≥18 years old will be eligible if, in CPRD records, they have: ≥1 year of data before the index event; no prescription for DAPT or anticoagulants in the preceding 3 months; a prescription for aspirin or DAPT within 2 months after discharge from the index event. The primary outcome will be any bleeding event (CPRD or HES) up to 12 months after the index event. We will estimate adjusted HR for time to first bleeding event comparing: aspirin and clopidogrel (reference) versus aspirin and prasugrel or aspirin and ticagrelor after PCI; and aspirin (reference) versus aspirin and clopidogrel after CABG and ACS. We will describe rates of bleeding in patients prescribed TT (DAPT plus an anticoagulant). Potential confounders will be identified systematically using literature review, semistructured interviews with clinicians and a short survey of clinicians. We will conduct sensitivity analyses addressing the robustness of results to the study's main limitation-that we will not be able to identify the intervention group for patients whose bleeding event occurs before a DAPT prescription in CPRD.

ETHICS AND DISSEMINATION

This protocol was approved by the Independent Scientific Advisory Committee for the UK Medicines and Healthcare Products Regulatory Agency Database Research (protocol 16_126R) and the South West Cornwall and Plymouth Research Ethics Committee (17/SW/0092). The findings will be presented in peer-reviewed journals, lay summaries and briefing papers to commissioners/other stakeholders.

TRIAL REGISTRATION NUMBER

76607611; Pre-results.

Relationship of stroke and bleeding risk profiles to efficacy and safety of dabigatran dual therapy versus warfarin triple therapy in atrial fibrillation after percutaneous coronary intervention: An ancillary analysis from the RE-DUAL PCI trial

BACKGROUND

In the RE-DUAL PCI trial of patients with atrial fibrillation (AF) who underwent percutaneous coronary intervention (PCI), dabigatran dual therapy (110 or 150 mg bid, plus clopidogrel or ticagrelor) reduced International Society on Thrombosis and Haemostasis bleeding events compared with warfarin triple therapy, with noninferiority in overall thromboembolic events. This analysis assessed outcomes in relation to patient bleeding and stroke risk profiles, based on the modified HAS-BLED and CHA₂DS₂-VASc scores.

METHODS

The primary endpoint, major bleeding event (MBE) or clinically relevant nonmajor bleeding event (CRNMBE), was compared across study arms in patients categorized by modified HAS-BLED score 0-2 or ≥3. The composite endpoint of death, thromboembolic event, and unplanned revascularization rates was compared in patients categorized by CHA₂DS₂-VASc score 0-1, 2, or ≥3.

RESULTS

Risk of MBE or CRNMBE was lower with dabigatran dual therapy (both doses) versus warfarin triple therapy, irrespective of modified HAS-BLED category (treatment-by-subgroup interaction P-value 0.584 and 0.273 for dabigatran 110 and 150 mg dual therapy, respectively, vs warfarin). Risk of the composite thromboembolic endpoint was similar across CHA₂DS₂-VASc categories and consistent with overall study results (interaction P-value 0.739 and 0.075 for dabigatran 110 and 150 mg dual therapy, respectively, vs warfarin). Higher HAS-BLED scores were associated with higher risks of bleeding in AF patients after PCI in a treatment-independent analysis.

CONCLUSION

Dabigatran dual therapy reduced bleeding events irrespective of bleeding risk category and demonstrated similar efficacy regardless of stroke risk category when compared with warfarin triple therapy.

Randomized evaluation of ticagrelor monotherapy after 3-month dual-antiplatelet therapy in patients with acute coronary syndrome treated with new-generation sirolimus-eluting stents: TICO trial rationale and design

BACKGROUND

Ticagrelor monotherapy after short-term dual-antiplatelet therapy (DAPT) may optimize ischemic and bleeding risks, particularly for acute coronary syndrome (ACS) patients, because its strategy is less potent than ticagrelor-based DAPT but more potent than aspirin or clopidogrel monotherapy.

METHODS

The TICO randomized open-label trial will evaluate whether ticagrelor monotherapy following 3-month DAPT is superior to 12-month ticagrelor-based DAPT in terms of net adverse clinical events (NACE) including efficacy and safety in ACS patients treated with ultrathin bioresorbable polymer sirolimus-eluting stents (BP-SES). Patients undergoing BP-SES implantation for ACS treatment will be randomized in a 1:1 fashion to the (1) ticagrelor monotherapy group after 3-month DAPT; or the (2) 12-month DAPT group. The primary endpoint is NACE within 12 months of percutaneous coronary intervention, which includes major adverse cardiac and cerebrovascular events (MACCE) plus major bleeding as defined by Thrombolysis in Myocardial Infarction. MACCE includes the composite of all-cause death, myocardial infarction, stent thrombosis, stroke, and target vessel revascularization. Secondary endpoints included each component of the primary endpoint.

CONCLUSIONS

The TICO trial is an ongoing trial evaluating the efficacy and safety of ticagrelor monotherapy following 3-month DAPT exclusively in ACS patients treated with uniform BP-SES. It may provide novel insights regarding the need for adjusted use of DAPT for rebalancing risk-benefit in current practice and changing from the conventional concept of aspirin maintenance to a ticagrelor-based regimen in the management of ACS.

Optimal duration of dual antiplatelet therapy post percutaneous coronary intervention in acute coronary syndrome

Dual antiplatelet therapy (DAPT), with aspirin plus a P2Y12 inhibitor agent, is the cornerstone treatment after percutaneous coronary intervention for acute coronary syndrome. Based on randomized clinical trial using aspirin and clopidogrel, a DAPT duration of 12 months has been recommended after an acute coronary syndrome. Despite the development of more potent antiplatelet agents (i.e. prasugrel and ticagrelor) and the reduction in ischemic recurrences after acute coronary syndrome, 12 months DAPT currently remains the gold standard. However, a significant proportion of patients experience recurrent ischemic events beyond the first 12 months after an acute coronary syndrome. Meanwhile, with more effective antiplatelet agent, bleeding has become a major safety concern on DAPT. Therefore, the ischemic and bleeding risk balance is central considering the duration of DAPT after an acute coronary syndrome. This review aims to report the evidence for an optimization and individualization of DAPT duration after an acute coronary syndrome.

Clinical Outcomes of Antithrombotic Strategies for Patients with Atrial Fibrillation After Percutaneous Coronary Intervention

Antithrombotic strategies for patients with atrial fibrillation (AF) undergoing percutaneous coronary intervention (PCI) remain challenging. This study aims to explore the best antithrombotic strategy for AF patients after PCI based on a network meta-analysis. This study was registered in PROSPERO (CRD42018093928). The PubMed, Cochrane, and EMBASE databases were searched to identify clinical trials concerning antithrombotic therapy for AF patients with PCI from inception to April 2018. Pairwise and network meta-analysis were conducted to compare clinical outcomes of different antithrombotic therapy. The primary endpoint was major bleeding. Fifteen studies including 16,382 patients were identified with follow-up ranging from 3 to 12 months. Non-vitamin K oral anticoagulants (NOAC) plus P2Y₁₂ inhibitor ranked first with a reduced risk of major bleeding compared with vitamin K antagonist (VKA) plus dual antiplatelet therapy (OR: 0.57, 95% CI: 0.43-0.75) but with no significant difference compared with VKA plus single platelet therapy (OR: 0.85, 95% CI: 0.62-1.16). Similar thrombotic events were evident among these groups. Subgroup analysis showed that VKA plus aspirin exhibited a similar risk of major bleeding compared with VKA plus clopidogrel (OR: 0.94, 95% CI: 0.73-1.23) but was associated with increased risks of ischaemic stroke (OR: 2.10, 95% CI: 1.33-3.32) and all-cause death (OR: 1.77, 95% CI: 1.15-2.74) versus VKA plus clopidogrel. In AF patients undergoing PCI, NOAC plus P2Y₁₂ inhibitor and VKA plus clopidogrel, but not VKA plus aspirin, were associated with reduced risk of major bleeding compared with the recommended VKA-based triple therapy, while thrombotic events were similar among these treatments.

Randomized trial of ticagrelor vs. aspirin in patients after coronary artery bypass grafting: the TiCAB trial

Aims

The antiplatelet treatment strategy providing optimal balance between thrombotic and bleeding risks in patients undergoing coronary artery bypass grafting (CABG) is unclear. We prospectively compared the efficacy of ticagrelor and aspirin after CABG.

Methods and results

We randomly assigned in double-blind fashion patients scheduled for CABG to either ticagrelor 90 mg twice daily or 100 mg aspirin (1:1) once daily. The primary outcome was the composite of cardiovascular death, myocardial infarction (MI), repeat revascularization, and stroke 12 months after CABG. The main safety endpoint was based on the Bleeding Academic Research Consortium classification, defined as BARC ≥4 for periprocedural and hospital stay-related bleedings and BARC ≥3 for post-discharge bleedings. The study was prematurely halted after recruitment of 1859 out of 3850 planned patients. Twelve months after CABG, the primary endpoint occurred in 86 out of 931 patients (9.7%) in the ticagrelor group and in 73 out of 928 patients (8.2%) in the aspirin group [hazard ratio 1.19; 95% confidence interval (CI) 0.87–1.62; P = 0.28]. All-cause mortality (ticagrelor 2.5% vs. aspirin 2.6%, hazard ratio 0.96, CI 0.53–1.72; P = 0.89), cardiovascular death (ticagrelor 1.2% vs. aspirin 1.4%, hazard ratio 0.85, CI 0.38–1.89; P = 0.68), MI (ticagrelor 2.1% vs. aspirin 3.4%, hazard ratio 0.63, CI 0.36–1.12, P = 0.12), and stroke (ticagrelor 3.1% vs. 2.6%, hazard ratio 1.21, CI 0.70–2.08; P = 0.49), showed no significant difference between the ticagrelor and aspirin group. The main safety endpoint was also not significantly different (ticagrelor 3.7% vs. aspirin 3.2%, hazard ratio 1.17, CI 0.71–1.92; P = 0.53).

Conclusion

In this prematurely terminated and thus underpowered randomized trial of ticagrelor vs. aspirin in patients after CABG no significant differences in major cardiovascular events or major bleeding could be demonstrated.

ClinicalTrials.gov Identifier

NCT01755520.

The impact of CYP2C19 and CYP4F2 variants and clinical factors on treatment outcomes during antiplatelet therapy

Aim: The aim of this study was to determine the impact of genetic and nongenetic factors on treatment outcomes in patients receiving dual antiplatelet therapy after percutaneous coronary intervention and stent implantation. Materials & methods: Patients (n = 628) used clopidogrel or ticagrelor for at least 1 week before platelet aggregation test. Results: Multivariate binary regression analysis demonstrated that aspirin use and CYP4F2 T allele significantly increased odds for bleeding in clopidogrel users (OR: 2.488, 95% CI: 1.452-4.265; p = 0.001 and OR: 1.573, 95% CI: 1.066-2.320; respectively; p = 0.022). CYP4F2 T allele significantly increased odds for bleeding in ticagrelor users (OR: 8.270, 95% CI: 3.917-17.462; p < 0.001). Conclusion: Aspirin use and CYP4F2 T allele were significantly associated with bleeding during dual antiplatelet therapy.

[Recommendations on the Use of Non-Vitamin K Antagonist Oral Anticoagulants in Patients with Atrial Fibrillation (Based on 2018 European Heart Rhythm Association Practical Guide)]

Non-vitamin K antagonist oral anticoagulants (NOACs) - direct oral anticoagulants - are getting the ever-broadening use in clinical practice. However, many problems related to optimal use of NOACs in specific clinical situations remain unresolved. European Heart Rhythm Association in April 2018 issued the renovated recommendations on the use of NOACs in patients with atrial fibrillation. The authors of recommendations presented some specific clinical variants for which they formulated practical advices based on the evidence obtained in randomized clinical trials. They also outlined the indications for use of NOACs, formulated practical start-program and scheme of subsequent follow-up management of patients taking NOACs. Recommendations contain information on pharmacokinetics of NOACs and their interactions with other drugs, consideration of feasibility of NOACs use in patients with chronic renal insufficiency or advanced liver disease. Many other practical problems are covered as well.

[Antithrombotic Therapy in Atrial Fibrillation and Chronic Ischemic Heart Disease]

The review is devoted to the use of antithrombotic therapy in patients with atrial fibrillation (AF) and chronic ischemic heart disease (IHD). We discuss data of international registries, meta-analyses assessing possibilities of the use of oral anticoagulants for secondary prevention of IHD. We present here results of randomized and observational clinical studies demonstrating advantages of prescription of monotherapy with oral anticoagulants (OAC) in combination of AF and chronic IHD. Modern evidence base of advantages of dual antithrombotic therapy with the use of direct OAC following percutaneous coronary intervention is also presented.

Duration of Clopidogrel-Based Dual Antiplatelet Therapy and Clinical Outcomes in Patients With Acute Coronary Syndrome Undergoing Percutaneous Coronary Intervention - A Real-World Observation in Taiwan From 2012 to 2015

BACKGROUND

Little information is available in Asia about the real-world practice of dual antiplatelet therapy (DAPT) duration for acute coronary syndrome (ACS) and its influence on clinical outcomes.

METHODS AND RESULTS

The Taiwan ACS STENT Registry was a prospective, multicenter study to observe ACS patients using clopidogrel-based DAPT after percutaneous coronary intervention (PCI). The primary outcome was a composite of cardiovascular death, myocardial infarction, and stroke. Overall, 2,221 ACS patients (62 years, 83% men) were included. DAPT duration was ≤9 months in 935 (42.1%). The incidence of primary outcome was higher in patients receiving DAPT ≤9 months compared with those receiving DAPT >9 months at 1 year (3.5% vs. 1.6%, P=0.0026). The incidence of stent thrombosis (overall 0.5%) was similar between groups. Multivariable analysis showed that DAPT >9 months was associated with a significantly lower risk of primary outcome (odds ratio 0.725, 95% confidence interval 0.545-0.965).

CONCLUSIONS

Our data showed that short duration of DAPT (≤9 months) was common (42.1%) in Taiwan for ACS patients undergoing PCI. DAPT ≤9 months increased the risk of the primary outcome.

Influence of Local Myocardial Infarction on Endothelial Function, Neointimal Progression, and Inflammation in Target and Non-Target Vascular Territories in a Porcine Model of Acute Myocardial Infarction

BACKGROUND

Patients with acute myocardial infarction (AMI) have worse clinical outcomes than those with stable coronary artery disease despite revascularization. Non-culprit lesions of AMI also involve more adverse cardiovascular events. This study aimed to investigate the influence of AMI on endothelial function, neointimal progression, and inflammation in target and non-target vessels.

METHODS

In castrated male pigs, AMI was induced by balloon occlusion and reperfusion into the left anterior descending artery (LAD). Everolimus-eluting stents (EES) were implanted in the LAD and left circumflex (LCX) artery 2 days after AMI induction. In the control group, EES were implanted in the LAD and LCX in a similar fashion without AMI induction. Endothelial function was assessed using acetylcholine infusion before enrollment, after the AMI or sham operation, and at 1 month follow-up. A histological examination was conducted 1 month after stenting.

RESULTS

A total of 10 pigs implanted with 20 EES in the LAD and LCX were included. Significant paradoxical vasoconstriction was assessed after acetylcholine challenge in the AMI group compared with the control group. In the histologic analysis, the AMI group showed a larger neointimal area and larger area of stenosis than the control group after EES implantation. Peri-strut inflammation and fibrin formation were significant in the AMI group without differences in injury score. The non-target vessel of the AMI also showed similar findings to the target vessel compared with the control group.

CONCLUSION

In the pig model, AMI events induced endothelial dysfunction, inflammation, and neointimal progression in the target and non-target vessels.

A brief review on resistance to P2Y12 receptor antagonism in coronary artery disease

Background

Platelet inhibition is important for patients with coronary artery disease. When dual antiplatelet therapy (DAPT) is required, a P2Y₁₂-antagonist is usually recommended in addition to standard aspirin therapy. The most used P2Y₁₂-antagonists are clopidogrel, prasugrel and ticagrelor. Despite DAPT, some patients experience adverse cardiovascular events, and insufficient platelet inhibition has been suggested as a possible cause. In the present review we have performed a literature search on prevalence, mechanisms and clinical implications of resistance to P2Y₁₂ inhibitors.

Methods

The PubMed database was searched for relevant papers and 11 meta-analyses were included. P2Y₁₂ resistance is measured by stimulating platelets with ADP ex vivo and the most used assays are vasodilator stimulated phosphoprotein (VASP), Multiplate, VerifyNow (VN) and light transmission aggregometry (LTA).

Discussion/conclusion

The frequency of high platelet reactivity (HPR) during clopidogrel therapy is predicted to be 30%. Genetic polymorphisms and drug-drug interactions are discussed to explain a significant part of this inter-individual variation. HPR during prasugrel and ticagrelor treatment is estimated to be 3–15% and 0–3%, respectively. This lower frequency is explained by less complicated and more efficient generation of the active metabolite compared to clopidogrel. Meta-analyses do show a positive effect of adjusting standard clopidogrel treatment based on platelet function testing. Despite this, personalized therapy is not recommended because no large-scale RCT have shown any clinical benefit. For patients on prasugrel and ticagrelor, platelet function testing is not recommended due to low occurrence of HPR.

Unmet Needs in Managing Myocardial Infarction in Patients With Malignancy

Patients with cancer face a high short-term risk of arterial thromboembolism. One of the most fatal manifestations of arterial thromboembolism is myocardial infarction (MI), and patients with cancer face a 3-fold greater risk of MI than patients without cancer. The individual risk for arterial thrombotic events in patients with cancer is determined by the complex interaction of baseline cardiovascular risk factors, cancer type and stage, chemotherapeutic regimen, and other general contributing factors for thrombosis. Managing MI in patients with cancer is a clinical challenge, particularly due to cancer's unique pathophysiology, which makes it difficult to balance thrombotic and bleeding risks in this specific patient population. When patients with cancer present with MI, a limited proportion are treated with guideline-recommended therapy, such as antiplatelet therapy or invasive revascularization. Despite the limited evidence, existing reports consistently suggest similar clinical benefits of guideline-recommended therapy when administered to patients with cancer presenting with MI. In this review, we briefly summarize the available evidence, clinical challenges, and future perspectives on simultaneous management of MI and cancer, with a focus on invasive strategy.

Use of PRECISE-DAPT Score and Admission Platelet Count to Predict Mortality Risk in Patients With Acute Coronary Syndrome

The PREdicting bleeding Complications In patients undergoing Stent implantation and subsEquent Dual Antiplatelet Therapy (PRECISE-DAPT) score has been validated to predict bleeding complications in patients undergoing stent implantation and dual antiplatelet therapy. This score does not include the platelet count (PC), which has been shown to be an independent marker of mortality in patients with acute coronary syndrome (ACS). We assessed the role of the PRECISE-DAPT score calculated on admission for mortality risk prediction and evaluated whether the predictive accuracy of this score improved by adding the PC. In a retrospective cohort study of 1000 patients with ACS, after adjustment for relevant covariates, a PRECISE-DAPT score ≥25 was independently associated with mortality (hazard ratio [HR]: 7.91; 95% confidence interval [CI]: 4.37-14.30). When this score was combined with PC, compared to patients with PRECISE-DAPT <25 and PC ≥150 × 10⁹/L, the adjusted HR was 7.2 (95% CI 2.4-21.6) for those with PRECISE-DAPT <25 and PC <150 × 10⁹/L; 10.7 (95% CI: 5.2-21.9) for those with PRECISE-DAPT ≥25 and PC ≥150 × 10⁹/L; and 17.9 (95% CI 7.0-45.4) for those with PRECISE-DAPT ≥25 and PC <150 × 10⁹/L. Selecting thresholds for high-risk designation, the PRECISE-DAPT score integrated with PC had a higher prediction value, compared to the PRECISE-DAPT and Global Registry of Acute Coronary Events scores.

[Oral anticoagulation and antiplatelet therapy in patients with atrial fibrillation after coronary interventions]

Dual antiplatelet therapy (DAPT) is the cornerstone of maintenance medication following elective percutaneous coronary intervention and also after acute coronary syndrome (ST-elevation myocardial infarction, non-ST-elevation myocardial infarction, unstable angina pectoris); however, DAPT is not sufficient for stroke prevention in atrial fibrillation (SPAF). For SPAF, oral anticoagulation (OAC) with vitamin K antagonists (VKA) or non-vitamin K-dependent anticoagulants (NOAC) is required. If a patient who is receiving anticoagulants for SPAF, requires a coronary intervention, triple therapy consisting of OAC plus DAPT is given, at least for a limited time following the procedure. This article reviews the current data from studies testing strategies with NOACs plus one or two antiplatelet substances in comparison to triple therapy with VKA.

A prospective interventional registry of short-term dual-antiplatelet treatment after implantation of drug-eluting stents in patients with atrial fibrillation requiring oral anticoagulation therapy

There are limited data regarding the use of antithrombotic therapy in patients with atrial fibrillation (AF) who underwent percutaneous coronary intervention (PCI) with drug-eluting stents (DES). In this prospective interventional study, we evaluated the feasibility of short-term dual-antiplatelet therapy (DAPT) after DES implantation in AF patients treated with oral anticoagulation (OAC). The antithrombotic regimen in the present study was 1-month DAPT, followed by single-antiplatelet therapy with OAC. A total of 285 consecutive patients were enrolled between 2015 and 2017. The mean CHA2DS2-VASc score was 3.91 ± 1.51. The duration of DAPT was 28.5 ± 11.5 days. At 1-year follow-up, serious bleeding complications, defined as Bleeding Academic Research Consortium type ≥ 2, were observed in 27 patients (9.5%). Multivariate analysis showed that previous history of bleeding episodes (P = 0.009) and continuation of aspirin (P = 0.003) were independent predictors for the serious bleeding complications. High ORBIT (P = 0.008) and PRECISE-DAPT (P = 0.002) scores were associated with the bleeding complications, and the cut-off values were 5.00 and 49.0, respectively. No definite stent thrombosis occurred in any of the patients. Short-term DAPT is feasible in AF patients treated with OAC after undergoing PCI with DES. The previous history of bleeding episodes and long-term aspirin use were associated with their 1-year serious bleeding events.

Dabigatran dual therapy with ticagrelor or clopidogrel after percutaneous coronary intervention in atrial fibrillation patients with or without acute coronary syndrome: a subgroup analysis from the RE-DUAL PCI trial

AIMS

After percutaneous coronary intervention (PCI) in patients with atrial fibrillation, safety and efficacy with dabigatran dual therapy were evaluated in pre-specified subgroups of patients undergoing PCI due to acute coronary syndrome (ACS) or elective PCI, and those receiving ticagrelor or clopidogrel treatment.

METHODS AND RESULTS

In the RE-DUAL PCI trial, 2725 patients were randomized to dabigatran 110 mg or 150 mg with P2Y12 inhibitor, or warfarin with P2Y12 inhibitor and aspirin. Mean follow-up was 14 months, 50.5% had ACS, and 12% received ticagrelor. The risk of the primary endpoint, major or clinically relevant non-major bleeding event, was reduced with both dabigatran dual therapies vs. warfarin triple therapy in patients with ACS [hazard ratio (95% confidence interval), 0.47 (0.35-0.63) for 110 mg and 0.67 (0.50-0.90) for 150 mg]; elective PCI [0.57 (0.43-0.76) for 110 mg and 0.76 (0.56-1.03) for 150 mg]; receiving ticagrelor [0.46 (0.28-0.76) for 110 mg and 0.59 (0.34-1.04) for 150 mg]; or clopidogrel [0.51 (0.41-0.64) for 110 mg and 0.73 (0.58-0.91) for 150 mg], all interaction P-values >0.10. Overall, dabigatran dual therapy was comparable to warfarin triple therapy for the composite endpoint of death, myocardial infarction, stroke, systemic embolism, or unplanned revascularization, with minor variations across the subgroups, all interaction P-values >0.10.

CONCLUSION

The benefits of both dabigatran 110 mg and 150 mg dual therapy compared with warfarin triple therapy in reducing bleeding risks were consistent across subgroups of patients with or without ACS, and patients treated with ticagrelor or clopidogrel.

Association between High Platelet Reactivity Following Dual Antiplatelet Therapy and Ischemic Events in Japanese Patients with Coronary Artery Disease Undergoing Stent Implantation

AIM

Although high on-treatment platelet reactivity (HTPR) with dual antiplatelet therapy (DAPT) correlates with long-term adverse outcomes in patients undergoing percutaneous coronary intervention, the correlation in Japanese patients remains unclear. Therefore, we examined the relationship between platelet reactivity during DAPT with aspirin and clopidogrel and 1-year clinical outcomes following successful coronary stent implantation.

METHODS

A prospective, multicenter registry study (j-CHIPS) was conducted in patients undergoing coronary stenting and receiving aspirin and clopidogrel at 16 hospitals in Japan. A VerifyNow point-of-care assay was used to assess platelet reactivity, and a cutoff value to define HTPR was established.

RESULTS

Between February 2011 and May 2013, 1047 patients were prospectively enrolled, of which 854 patients with platelet function evaluation at 12-24 h after PCI were included in the final analysis. After 1 year of follow-up, the incidence of the primary endpoint (a composite of all-cause mortality, myocardial infarction, stent thrombosis, and ischemic stroke) was significantly higher in patients with HTPR than in those without (5.9% vs. 1.5%, p=0.008), and HTPR showed a modest ability to discriminate between patients who did and did not experience major adverse cardiac and cerebrovascular events (area under the curve, 0.60; 95% confidence interval, 0.511-0.688, p=0.039). HTPR status did not identify patients at risk for major or minor bleeding events.

CONCLUSION

HTPR was significantly associated with adverse ischemic outcomes at 1 year after PCI in Japanese patients receiving maintenance DAPT, indicating its potential as a prognostic indicator of clinical outcomes in this high-risk patient population.

Clinical and angiographic outcomes of bioabsorbable vs. permanent polymer drug-eluting stents in Sweden: a report from the Swedish Coronary and Angioplasty Registry (SCAAR)

Aims

Randomized clinical trials have consistently demonstrated the non-inferiority of bioabsorbable polymer drug-eluting stents (BP-DES) with respect to DES having permanent polymers (PP-DES). To date, the comparative performance of BP- and PP-DES in the real world has not been extensively investigated.

Methods and results

From October 2011 to June 2016, we analysed the outcomes associated with newer generation DES use in Sweden. After stratification according to the type of DES received at the index procedure, a total of 16 504 and 79 106 stents were included in the BP- and PP-DES groups, respectively. The Kaplan–Meier estimates for restenosis at 2 years were 1.2% and 1.4% in BP- and PP-DES groups, respectively. Definite stent thrombosis (ST) was low in both groups (0.5% and 0.7% in BP- and PP-DES groups, respectively). The adjusted hazard ratio (HR) for either restenosis or definite ST did not differ between BP- and PP-DES [adjusted HR 0.95, 95% confidence interval (CI) 0.74–1.21; P = 0.670 and adjusted HR 0.79, 95% CI 0.57–1.09; P = 0.151, respectively]. Similarly, there were no differences in the adjusted risk of all-cause death and myocardial infarction (MI) between the two groups (adjusted HR for all-cause death 1.01, 95% CI 0.82–1.25; P = 0.918 and adjusted HR for MI 1.05, 95% CI 0.93–1.19; P = 0.404).

Conclusion

In a large, nationwide, and unselected cohort of patients, percutaneous coronary intervention with BP-DES implantation was not associated with an incremental clinical benefit over PP-DES use at 2 years follow-up.

Antibody-Based Ticagrelor Reversal Agent in Healthy Volunteers

BACKGROUND

Ticagrelor is an oral P2Y₁₂ inhibitor that is used with aspirin to reduce the risk of ischemic events among patients with acute coronary syndromes or previous myocardial infarction. Spontaneous major bleeding and bleeding associated with urgent invasive procedures are concerns with ticagrelor, as with other antiplatelet drugs. The antiplatelet effects of ticagrelor cannot be reversed with platelet transfusion. A rapid-acting reversal agent would be useful.

METHODS

In this randomized, double-blind, placebo-controlled, phase 1 trial, we evaluated intravenous PB2452, a monoclonal antibody fragment that binds ticagrelor with high affinity, as a ticagrelor reversal agent. We assessed platelet function in healthy volunteers before and after 48 hours of ticagrelor pretreatment and again after the administration of PB2452 or placebo. Platelet function was assessed with the use of light transmission aggregometry, a point-of-care P2Y₁₂ platelet-reactivity test, and a vasodilator-stimulated phosphoprotein assay.

RESULTS

Of the 64 volunteers who underwent randomization, 48 were assigned to receive PB2452 and 16 to receive placebo. After 48 hours of ticagrelor pretreatment, platelet aggregation was suppressed by approximately 80%. PB2452 administered as an initial intravenous bolus followed by a prolonged infusion (8, 12, or 16 hours) was associated with a significantly greater increase in platelet function than placebo, as measured by multiple assays. Ticagrelor reversal occurred within 5 minutes after the initiation of PB2452 and was sustained for more than 20 hours (P<0.001 after Bonferroni adjustment across all time points for all assays). There was no evidence of a rebound in platelet activity after drug cessation. Adverse events related to the trial drug were limited mainly to issues involving the infusion site.

CONCLUSIONS

In healthy volunteers, the administration of PB2452, a specific reversal agent for ticagrelor, provided immediate and sustained reversal of the antiplatelet effects of ticagrelor, as measured by multiple assays. (Funded by PhaseBio Pharmaceuticals; ClinicalTrials.gov number, NCT03492385.).

Advances in Antiplatelet Therapy for Dentofacial Surgery Patients: Focus on Past and Present Strategies

BACKGROUND

Nowadays, patients involved in antiplatelet therapy required special attention during oral surgery procedures, due to the antiplatelet drugs assumption. The motivations of the assumption may be different and related to the patient's different systemic condition. For this reason, accordingly to the current international guidelines, different protocols can be followed. The aim of this work is to analyze how the dentist's approach to these patients has changed from the past to the present, evaluating the risk exposure for the patients.

METHODS

This review paper considered different published papers in literature through quoted scientific channels, going in search of "ancient" works in such a way as to highlight the differences in the protocols undertaken. The analyzed manuscripts are in the English language, taking into consideration reviews, case reports, and case series in such a way as to extrapolate a sufficient amount of data and for evaluating the past therapeutic approaches compared to those of today.

RESULTS

Colleagues in the past preferred to subject patients to substitution therapy with low molecular weight anticoagulants, by suspending antiplatelet agents to treatment patients, often for an arbitrary number of days. The new guidelines clarify everything, without highlighting an increased risk of bleeding during simple oral surgery in patients undergoing antiplatelet therapy.

CONCLUSION

Either patients take these medications for different reasons, because of cardiovascular pathologies, recent cardiovascular events, or even for simple prevention, although the latest research shows that there is no decrease of cardiovascular accidents in patients who carry out preventive therapy. Surely, it will be at the expense of the doctor to assess the patient's situation and risk according to the guidelines. For simple oral surgery, it is not necessary to stop therapy with antiplatelet agents because the risk of bleeding has not increased, and is localized to a post-extraction alveolus or to an implant preparation, compared to patients who do not carry out this therapy. From an analysis of the results it emerges that the substitutive therapy should no longer be performed and that it is possible to perform oral surgery safely in patients who take antiplatelet drugs, after a thorough medical history. Furthermore, by suspending therapy, we expose our patients to more serious risks, concerning their main pathology, where present.

A Multidisciplinary Approach on the Perioperative Antithrombotic Management of Patients With Coronary Stents Undergoing Surgery: Surgery After Stenting 2

Perioperative management of antithrombotic therapy in patients treated with coronary stents undergoing surgery remains poorly defined. Importantly, surgery represents a common reason for premature treatment discontinuation, which is associated with an increased risk in mortality and major adverse cardiac events. However, maintaining antithrombotic therapy to minimize the incidence of perioperative ischemic complications may increase the risk of bleeding complications. Although guidelines provide some recommendations with respect to the perioperative management of antithrombotic therapy, these have been largely developed according to the thrombotic risk of the patient and a definition of the hemorrhagic risk specific to each surgical procedure, key to defining the trade-off between ischemia and bleeding, is not provided. These observations underscore the need for a multidisciplinary collaboration among cardiologists, anesthesiologists, hematologists and surgeons to reach this goal. The present document is an update on practical recommendations for standardizing management of antithrombotic therapy management in patients treated with coronary stents (Surgery After Stenting 2) in various types of surgery according to the predicted individual risk of thrombotic complications against the anticipated risk of surgical bleeding complications. Cardiologists defined the thrombotic risk using a "combined ischemic risk" approach, while surgeons classified surgeries according to their inherent hemorrhagic risk. Finally, a multidisciplinary agreement on the most appropriate antithrombotic treatment regimen in the perioperative phase was reached for each surgical procedure.

Combined association of key risk factors on ischaemic outcomes and bleeding in patients with myocardial infarction

Objective

In patients with myocardial infarction (MI), risk factors for bleeding and ischaemic events tend to overlap, but the combined effects of these factors have scarcely been studied in contemporary real-world settings. We aimed to assess the combined associations of established risk factors using nationwide registries.

Methods

Using the Swedish Web-system for Enhancement and Development of Evidence-based care in Heart disease Evaluated According to Recommended Therapies registry, patients with invasively managed MI in 2006–2014 were included. Six factors were assessed in relation to cardiovascular death (CVD)/MI/stroke, and major bleeding: age ≥65, chronic kidney disease, diabetes, multivessel disease, prior bleeding and prior MI.

Results

We studied 100 879 patients, of whom 20 831 (20.6%) experienced CVD/MI/stroke and 5939 (5.9%) major bleeding, during 3.6 years median follow-up. In adjusted Cox models, all factors were associated with CVD/MI/stroke, and all but prior MI were associated with major bleeding. The majority (53.5%) had ≥2 risk factors. With each added risk factor, there was a marked but gradual increase in incidence of the CVD/MI/stroke. This was seen also for major bleeding, but to a lesser extent, largely driven by prior bleeding as the strongest risk factor.

Conclusions

The majority of patients with MI had two or more established risk factors. Increasing number of risk factors was associated with higher rate of ischaemic events. When excluding patients with prior major bleeding, bleeding incidence rate increased only minimally with increasing number of risk factors. The high ischaemic risk in those with multiple risk factors highlights an unmet need for additional preventive measures.

In-stent Massive Thrombi Formation During Primary Percutaneous Coronary Intervention in a Patient with Acute Myocardial Infarction Complicated with Essential Thrombocythemia

A 61-year-old man with essential thrombocythemia (ET) presented with acute myocardial infarction (AMI) and underwent primary percutaneous coronary intervention. After stent deployment from the left main (LM) to the left anterior descending artery, intravascular ultrasound revealed thrombi formation in the whole stent. Two days later, optical frequency domain imaging confirmed stent malapposition and thrombi remaining in only the LM. The stent malapposition and ET might have contributed to this phenomenon. He underwent an additional stent expansion and aggressive anti-thrombotic regimen. AMI complicated with ET carries increased risks of in-stent thrombi formation and requires careful revascularization and aggressive pharmacotherapy.

Effect of Perioperative Antiplatelet Therapy on Outcomes in Patients With Drug-Eluting Stents Undergoing Elective Noncardiac Surgery

We investigated the association of perioperative antiplatelet therapy (APT) and outcomes in patients with drug-eluting stent (DES) placement for noncardiac surgery (NCS). In consecutive 23,358 patients who underwent percutaneous coronary interventions between 2005 and 2016, total of 2,179 patients that required 2,179 elective NCS after DES placement were retrospectively analyzed. A net adverse clinical event (NACE), composite of death, myocardial infarction, stent thrombosis, and major bleeding, was assessed at 30 days. Of 2,179 patients, 937 patients (43%) underwent NCS with discontinuation of APT. For overall, NACE occurred in 10 patients who discontinued APT (1.1%) and 22 patients who continued APT (1.8%) without significant differences (hazard ratio [HR] 0.60, 95% confidence interval [CI] 0.28 to 1.27, p = 0.182). Also, adjusted NACE event rates were not different between groups for overall NCSs (adjusted HR 0.76, 95% CI 0.38 to 1.52, p = 0.440), for NCSs >1, ≤12 months after DES, and for NCSs >12 months after DES. Our findings persisted (adjusted HR 1.26, 95% CI 0.51 to 3.10, p = 0.618) when those who continued dual-APT were excluded from the continuation of APT group due to a higher tendency of NACE compared with those who continued single-APT (adjusted HR 2.26, 95% CI 0.98 to 5.21, p = 0.055). However, the patients who discontinued APT for >7 days had a significantly higher NACE than those who discontinued for ≤7 days (adjusted HR 6.93, 95% CI 2.16 to 22.24, p = 0.001). In conclusion, discontinuation of APT may not be associated with higher NACEs 30 days postsurgery compared with continuation of APT, when APT was discontinued for ≤7 days in patients undergoing elective NCS after DES implantation.

De-escalation of anti-platelet therapy in patients with acute coronary syndromes undergoing percutaneous coronary intervention: a narrative review

Objective:

Dual antiplatelet therapy (DAPT) with aspirin and a P2Y₁₂ receptor inhibitor is the cornerstone of treatment in patients with acute coronary syndromes (ACS) and in those undergoing percutaneous coronary intervention (PCI). In current clinical situation, availability of different oral P2Y₁₂ inhibitors (clopidogrel, prasugrel, and ticagrelor) has enabled physicians to switch among therapies owing to specific clinical scenarios. Although optimum time, loading dose and interval of transition between P2Y₁₂ inhibitors is still controversial and needs further evidence, switching between oral inhibitors frequently occurs in clinical practice for several reasons.

Data sources:

This review was based on data in articles published in PubMed up to June 2018, with the following keywords “antiplatelet therapy”, “ACS”, “PCI”, “ticagrelor”, and “clopidogrel”.

Study selection:

Original articles and critical reviews on de-escalation strategy in ACS patients after PCI were selected. References of the retrieved articles were also screened to search for potentially relevant papers.

Results:

Safety concerns associated with switching between antiplatelet agents, has prompted the use of clopidogrel for patients with ACS especially after PCI as a de-escalation strategy. Practical considerations for de-escalating therapies in patients with ACS such as reducing dose of P2Y₁₂ inhibitors or shortening duration of DAPT (followed by aspirin or P2Y₁₂ receptor inhibitor monotherapy) as potential options are yet to be standardized and validated.

Conclusions:

Current review will provide an overview of the pharmacology of common P2Y₁₂ inhibitors, definitions of de-escalation and different de-escalating strategies and its outcomes, along with possible direction to be explored in de-escalation.

Platelet reactivity and clinical outcomes in acute coronary syndrome patients treated with prasugrel and clopidogrel: a pre-specified exploratory analysis from the TROPICAL-ACS trial

Aims

The value of platelet function testing (PFT) in predicting clinical outcomes and guiding P2Y12-inhibitor treatment is uncertain. In a pre-specified sub-study of the TROPICAL-ACS trial, we assessed ischaemic and bleeding risks according to high platelet reactivity (HPR) and low platelet reactivity (LPR) to ADP in patients receiving uniform prasugrel vs. PFT-guided clopidogrel or prasugrel.

Methods and results

Acute coronary syndrome patients with PFT done 14 days after hospital discharge were included with prior randomization to uniform prasugrel for 12 months (control group, no treatment modification) vs. early de-escalation from prasugrel to clopidogrel and PFT-guided maintenance treatment (HPR: switch-back to prasugrel, non-HPR: clopidogrel). The composite ischaemic endpoint included cardiovascular death, myocardial infarction, or stroke, while key safety outcome was Bleeding Academic Research Consortium (BARC) 2–5 bleeding, from PFT until 12 months. We identified 2527 patients with PFT results available: 1266 were randomized to the guided and 1261 to the control group. Before treatment adjustment, HPR was more prevalent in the guided group (40% vs. 15%), while LPR was more common in control patients (27% vs. 11%). Compared to control patients without HPR on prasugrel (n = 1073), similar outcomes were observed in guided patients kept on clopidogrel [n = 755, hazard ratio (HR): 1.06 (0.57–1.95), P = 0.86] and also in patients with HPR on clopidogrel switched to prasugrel [n = 511, HR: 0.96 (0.47–1.96), P = 0.91]. In contrast, HPR on prasugrel was associated with a higher risk for ischaemic events in control patients [n = 188, HR: 2.16 (1.01–4.65), P = 0.049]. Low platelet reactivity was an independent predictor of bleeding [HR: 1.74 (1.18–2.56), P = 0.005], without interaction (Pint = 0.76) between study groups.

Conclusion

Based on this substudy of a randomized trial, selecting prasugrel or clopidogrel based on PFT resulted in similar ischaemic outcomes as uniform prasugrel therapy without HPR. Although infrequent, HPR on prasugrel was associated with increased risk of ischaemic events. Low platelet reactivity was a strong and independent predictor of bleeding both on prasugrel and clopidogrel.

Duration of Dual Antiplatelet Therapy in Patients with CKD and Drug-Eluting Stents: A Meta-Analysis

BACKGROUND AND OBJECTIVES

Whether prolonged dual antiplatelet therapy (DAPT) is more protective in patients with CKD and drug-eluting stents compared with shorter DAPT is uncertain. The purpose of this meta-analysis was to examine whether shorter DAPT in patients with drug-eluting stents and CKD is associated with lower mortality or major adverse cardiovascular event rates compared with longer DAPT.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

A Medline literature research was conducted to identify randomized trials in patients with drug-eluting stents comparing different DAPT duration strategies. Inclusion of patients with CKD was also required. The primary outcome was a composite of all-cause mortality, myocardial infarction, stroke, or stent thrombosis (definite or probable). Major bleeding was the secondary outcome. The risk ratio (RR) was estimated using a random-effects model.

RESULTS

Five randomized trials were included (1902 patients with CKD). Short DAPT (≤6 months) was associated with a similar incidence of the primary outcome, compared with 12-month DAPT among patients with CKD (48 versus 50 events; RR, 0.93; 95% confidence interval [95% CI], 0.64 to 1.36; P=0.72). Twelve-month DAPT was also associated with a similar incidence of the primary outcome compared with extended DAPT (≥30 months) in the CKD subgroup (35 versus 35 events; RR, 1.04; 95% CI, 0.67 to 1.62; P=0.87). Numerically lower major bleeding event rates were detected with shorter versus 12-month DAPT (9 versus 13 events; RR, 0.69; 95% CI, 0.30 to 1.60; P=0.39) and 12-month versus extended DAPT (9 versus 12 events; RR, 0.83; 95% CI, 0.35 to 1.93; P=0.66) in patients with CKD.

CONCLUSIONS

Short DAPT does not appear to be inferior to longer DAPT in patients with CKD and drug-eluting stents. Because of imprecision in estimates (few events and wide confidence intervals), no definite conclusions can be drawn with respect to stent thrombosis.