Ticagrelor versus Clopidogrel in Symptomatic Peripheral Artery Disease

[Peripheral arterial disease: Treatment]

Medical management of peripheral arterial disease (PAD) patients is aimed at limb symptom relief and reducing systemic major adverse events risk. For the first purpose: exercise therapy is recommended in case of claudication; multidisciplinary evaluation for surgical options is mandatory in case of critical limb ischaemia. Reducing cardiac and stroke risk can be achieved through: statin prescription in most of the cases; antiplatelet agents in symptomatic PAD patients; cardio-vascular risk factors control.

Low-Density Lipoprotein Cholesterol Lowering With Evolocumab and Outcomes in Patients With Peripheral Artery Disease: Insights From the FOURIER Trial (Further Cardiovascular Outcomes Research With PCSK9 Inhibition in Subjects With Elevated Risk)

BACKGROUND

The PCSK9 (proprotein convertase subtilisin/kexin type 9) inhibitor evolocumab reduced low-density lipoprotein cholesterol and cardiovascular events in the FOURIER trial (Further Cardiovascular Outcomes Research With PCSK9 Inhibition in Subjects With Elevated Risk). We investigated the efficacy and safety of evolocumab in patients with peripheral artery disease (PAD) as well as the effect on major adverse limb events.

METHODS

FOURIER was a randomized trial of evolocumab versus placebo in 27 564 patients with atherosclerotic disease on statin therapy followed for a median of 2.2 years. Patients were identified as having PAD at baseline if they had intermittent claudication and an ankle brachial index of <0.85, or if they had a prior peripheral vascular procedure. The primary end point was a composite of cardiovascular death, myocardial infarction, stroke, hospital admission for unstable angina, or coronary revascularization. The key secondary end point was a composite of cardiovascular death, myocardial infarction, or stroke. An additional outcome of interest was major adverse limb events defined as acute limb ischemia, major amputation, or urgent peripheral revascularization for ischemia.

RESULTS

Three thousand six hundred forty-two patients (13.2%) had PAD (1505 with no prior myocardial infarction or stroke). Evolocumab significantly reduced the primary end point consistently in patients with PAD (hazard ratio [HR] 0.79; 95% confidence interval [CI], 0.66-0.94; P=0.0098) and without PAD (HR 0.86; 95% CI, 0.80-0.93; P=0.0003; P_interaction=0.40). For the key secondary end point, the HRs were 0.73 (0.59-0.91; P=0.0040) for those with PAD and 0.81 (0.73-0.90; P<0.0001) for those without PAD (P_interaction=0.41). Because of their higher risk, patients with PAD had larger absolute risk reductions for the primary end point (3.5% with PAD, 1.6% without PAD) and the key secondary end point (3.5% with PAD, 1.4% without PAD). Evolocumab reduced the risk of major adverse limb events in all patients (HR, 0.58; 95% CI, 0.38-0.88; P=0.0093) with consistent effects in those with and without known PAD. There was a consistent relationship between lower achieved low-density lipoprotein cholesterol and lower risk of limb events (P=0.026 for the beta coefficient) that extended down to <10 mg/dL.

CONCLUSIONS

Patients with PAD are at high risk of cardiovascular events, and PCSK9 inhibition with evolocumab significantly reduced that risk with large absolute risk reductions. Moreover, lowering of low-density lipoprotein cholesterol with evolocumab reduced the risk of major adverse limb events.

CLINICAL TRIAL REGISTRATION

URL: https://www.clinicaltrials.gov. Unique identifier: NCT01764633.

Review of aspirin and clopidogrel resistance in peripheral arterial disease

OBJECTIVE

Aspirin resistance (AR) and clopidogrel resistance (CR) are terms used to describe a reduction in the medication's efficacy in inhibiting platelet aggregation despite regular dosing. This review gives context to the clinical role and implications of antiplatelet resistance in peripheral arterial disease (PAD).

METHODS

A review of English-language literature on AR and CR in PAD involving human subjects using PubMed and MEDLINE databases was performed in April 2017. A total of 2075 patients in 22 relevant studies were identified. To give this issue context, a review of the larger, more established literature on antiplatelet resistance in coronary disease was undertaken, identifying significant research associating resistance to major adverse cardiovascular events (MACEs).

RESULTS

Studies in the coronary arterial disease literature have strongly associated antiplatelet resistance with increased MACE. Prevalence of AR or CR in coronary disease appears to be >55% for each in some studies. Meta-analyses of >50 studies revealed that AR and CR are significantly associated with MACE (relative risk of 2.09 and 2.8, respectively). This adds further weight to the literature reporting antiplatelet resistance as an independent predictor of and a threefold risk factor for major adverse cardiovascular events. The prevalence of resistance in PAD in this review was comparable to that in the coronary disease literature, with AR and CR prevalence up to 60% and 65%, respectively. There is evidence that the adverse effects of antiplatelet resistance are significant in PAD. In fact, research directly studying stent thrombosis populations with either coronary arterial disease or PAD revealed more significantly impaired platelet responsiveness to clopidogrel and aspirin in PAD compared with similar individuals with coronary disease. AR in PAD was found in studies to be a significant risk factor for iliofemoral stent reocclusion (P = .0093) and stroke in patients with symptomatic carotid disease (P = .018). CR was found to be a significant, independent risk factor in predicting ischemic outcomes in several recent PAD studies (P < .0001). Loss-of-function carriers of enzyme CYP2C19, important in clopidogrel metabolism, have a 30% greater risk of ischemic events (P < .001). Importantly, less antiplatelet drug resistance may be encountered with newer antiplatelet agents, including ticagrelor and prasugrel, because of reduced enzymatic polymorphisms.

CONCLUSIONS

The limited research addressing AR and CR in PAD suggests that further research is required to clarify the role of platelet assays and potential for individualized antiplatelet therapy.

Short vs prolonged dual antiplatelet treatment upon endovascular stenting of peripheral arteries

INTRODUCTION

Peripheral artery disease (PAD) is a highly prevalent disorder with a substantial economical burden. Dual antiplatelet treatment (DAPT) upon endovascular stenting to prevent acute thrombotic reocclusions is an universally accepted practice for postinterventional management of PAD patients. However, the optimal period of time for DAPT upon endovascular stenting is not known.

METHODS

In the current nonrandomized, retrospective monocentric study, we evaluated the duration of DAPT upon endovascular stenting. A total of 261 endovascular SFA and iliac stenting procedures were performed on 214 patients and these patients were subdivided into a short (4-6 weeks) or a prolonged (8-12 weeks) DAPT regime group. More than 65% of the patients included were male, approximately 35% were diabetic, and 61% had a history of smoking. Of all the patients, 90% exhibited a Rutherford stage 2-3, and approximately half of the patients had a moderate-to-severe calcified target lesion with a length of >13 cm. Major safety end points were defined as any bleeding, compartment syndrome, and ischemic events. In addition to this, patency, all-cause mortality, as well as amputation were followed up over a period of 12 months upon intervention.

RESULTS

Twelve months after endovascular stenting, primary patency in our cohort was comparable between the groups (83.94% short vs 79.8% long DAPT, P>0.05). Major bleeding occurred in 18 cases without any difference between the groups (P>0.05). In addition, during the 12-month follow-up, 6 (3.4%) patients in the short and 3 (3.5%) in the prolonged DAPT regime suffered a stroke/transient ischemic attack (P>0.05). In addition, there was no difference regarding mortality and amputation rate comparing short vs prolonged DAPT regime in a 12-month follow-up.

CONCLUSION

In the current cohort, prolonged DAPT after endovascular stenting had no beneficial effect on the outcome in a 12-month follow-up.

Rivaroxaban with or without Aspirin in Stable Cardiovascular Disease

BACKGROUND

We evaluated whether rivaroxaban alone or in combination with aspirin would be more effective than aspirin alone for secondary cardiovascular prevention.

METHODS

In this double-blind trial, we randomly assigned 27,395 participants with stable atherosclerotic vascular disease to receive rivaroxaban (2.5 mg twice daily) plus aspirin (100 mg once daily), rivaroxaban (5 mg twice daily), or aspirin (100 mg once daily). The primary outcome was a composite of cardiovascular death, stroke, or myocardial infarction. The study was stopped for superiority of the rivaroxaban-plus-aspirin group after a mean follow-up of 23 months.

RESULTS

The primary outcome occurred in fewer patients in the rivaroxaban-plus-aspirin group than in the aspirin-alone group (379 patients [4.1%] vs. 496 patients [5.4%]; hazard ratio, 0.76; 95% confidence interval [CI], 0.66 to 0.86; P<0.001; z=-4.126), but major bleeding events occurred in more patients in the rivaroxaban-plus-aspirin group (288 patients [3.1%] vs. 170 patients [1.9%]; hazard ratio, 1.70; 95% CI, 1.40 to 2.05; P<0.001). There was no significant difference in intracranial or fatal bleeding between these two groups. There were 313 deaths (3.4%) in the rivaroxaban-plus-aspirin group as compared with 378 (4.1%) in the aspirin-alone group (hazard ratio, 0.82; 95% CI, 0.71 to 0.96; P=0.01; threshold P value for significance, 0.0025). The primary outcome did not occur in significantly fewer patients in the rivaroxaban-alone group than in the aspirin-alone group, but major bleeding events occurred in more patients in the rivaroxaban-alone group.

CONCLUSIONS

Among patients with stable atherosclerotic vascular disease, those assigned to rivaroxaban (2.5 mg twice daily) plus aspirin had better cardiovascular outcomes and more major bleeding events than those assigned to aspirin alone. Rivaroxaban (5 mg twice daily) alone did not result in better cardiovascular outcomes than aspirin alone and resulted in more major bleeding events. (Funded by Bayer; COMPASS ClinicalTrials.gov number, NCT01776424 .).

Antiplatelet Agents for the Treatment and Prevention of Coronary Atherothrombosis

Antiplatelet drugs provide first-line antithrombotic therapy for the management of acute ischemic syndromes (both coronary and cerebrovascular) and for the prevention of their recurrence. Their role in the primary prevention of atherothrombosis remains controversial because of the uncertain balance of the potential benefits and risks when combined with other preventive strategies. The aim of this consensus document is to review the evidence for the efficacy and safety of antiplatelet drugs, and to provide practicing cardiologists with an updated instrument to guide their choice of the most appropriate antiplatelet strategy for the individual patient presenting with different clinical manifestations of coronary atherothrombosis, in light of comorbidities and/or interventional procedures.

The PARTHENON Clinical Development Program: the Role of Ticagrelor in Patients with Atherothrombotic Disease

Although the rate of cardiovascular disease (CVD)-related mortality has declined over the last decade, it is still the leading cause of mortality in the USA, accounting for over 1.4 million deaths annually. In addition, total direct (primarily hospital admissions) and indirect costs of CVD in the US is over $316 billion annually and is expected to grow to over $918 billion by 2030. Much of the etiology of CVD is due to atherosclerosis and its thrombotic complications, and central to this is the role of platelets. Atherosclerosis is a systemic disease, with meaningful morbidity and mortality when present in the coronary, cerebral, or major peripheral arteries. The recommended antiplatelet therapy differs based on the vascular bed impacted, with the optimal antiplatelet therapy yet to be defined. The PARTHENON program is a series of completed and ongoing phase III clinical trials investigating the efficacy and safety of ticagrelor in atherosclerotic CVD in comparison with established antiplatelet therapy or placebo. The overall aim of the program is to determine if more potent antiplatelet therapy, with different pharmacology, may reduce cardiovascular events in patients with atherosclerotic disease.

Underutilization of antiplatelet and statin therapy after postoperative myocardial infarction following vascular surgery

OBJECTIVE

The objective of this study was to investigate adherence to practice guidelines for antiplatelet and statin use after postoperative myocardial infarction (POMI) and its effect on late mortality following vascular surgery in a multicenter registry.

METHODS

Antiplatelet and statin use was examined in 1749 vascular surgery procedures with POMI within the Vascular Quality Initiative (VQI) from 2005 to 2015. Our primary aim was to assess cardiac medication (CM) use at discharge, defined as (1) single antiplatelet therapy (SAPT; aspirin or P2Y₁₂ inhibitor) or dual antiplatelet therapy (DAPT; aspirin and P2Y₁₂ inhibitor) and (2) statin therapy. Long-term mortality in patients with POMI was analyzed on the basis of discharge CM. A proportional hazards model was developed to control for factors associated with mortality. Regional differences in CM use at discharge after POMI were compared.

RESULTS

Overall discharge CM use after POMI included aspirin (81%), P2Y₁₂ inhibitor (38%), statin therapy (76%), and combined antiplatelet and statin (74%). At discharge, 26% of patients were not receiving combined antiplatelet and statin therapy. SAPT (50%) was more common than DAPT (35%; P < .001). Patients with POMI undergoing carotid endarterectomy were more likely to be discharged on CM (80%) compared with patients undergoing infrainguinal bypass (78%), suprainguinal bypass (72%), endovascular aneurysm repair (71%), and open abdominal aortic aneurysm repair (59%; P < .001). Patients receiving SAPT or DAPT plus statin therapy had improved survival (79%) compared with those receiving noncombination or no therapy (69%) with mean follow-up of 5.5 years and 4.9 years, respectively (log-rank, P = .001). After adjustment for covariates including preoperative medications, treatment with SAPT or DAPT plus statin at discharge was associated with lower late mortality compared with noncombination or no therapy (hazard ratio, 0.72; 95% confidence interval, 0.56-0.93; P = .01). Regional variation in CM at discharge following POMI was also observed with a range of 33% to 100% (P = .05).

CONCLUSIONS

Within the VQI, regional and procedure-specific variation exists in CM regimen after POMI following vascular surgery. Absence of combined antiplatelet and statin therapy at discharge after POMI was associated with higher late mortality and represents an area for quality improvement in the care of these patients.

How I use laboratory monitoring of antiplatelet therapy

Antiplatelet therapy is of proven benefit in coronary artery disease and a number of other clinical settings. This article reviews platelet function, molecular targets of antiplatelet agents, and clinical indications for antiplatelet therapy before focusing on a frequent question to hematologists about the 2 most commonly used antiplatelet therapies: Could the patient be aspirin “resistant” or clopidogrel “resistant”? If so, should results of a platelet function test be used to guide the dose or type of antiplatelet therapy? Whether such guided therapy is of clinical benefit to patients has been a source of controversy. The present article reviews this subject in the context of 2 prototypical clinical cases. Available evidence does not support the use of laboratory tests to guide the dose of aspirin or clopidogrel in patients with so-called aspirin or clopidogrel “resistance.”

Peripheral interventions and antiplatelet therapy: Role in current practice

Peripheral arterial disease (PAD) is a common disorder associated with a high risk of cardiovascular mortality and continues to be under-recognized. The major risk factors for PAD are similar to those for coronary and cerebrovascular disease. Management includes exercise program, pharmacologic therapy and revascularization including endovascular and surgical approach. The optimal revascularization strategy, endovascular or surgical intervention, is often debated due to the paucity of head to head randomized controlled studies. Despite significant advances in endovascular interventions resulting in increased utilization over surgical bypass, significant challenges still remain. Platelet activation and aggregation after percutaneous transluminal angioplasty of atherosclerotic arteries are important risk factors for re-occlusion/restenosis and life-threatening thrombosis following endovascular procedures. Antiplatelet agents are commonly prescribed to reduce the risk of myocardial infarction, stroke and death from cardiovascular causes in patients with PAD. Despite an abundance of data demonstrating efficacy of antiplatelet therapy in coronary artery disease and cerebrovascular disease, there is a paucity of clinical information, clinical guidelines and randomized controlled studies in the PAD population. Hence, data on antiplatelet therapy in coronary interventions is frequently extrapolated to peripheral interventions. The aim of this review article is to elucidate the current data on revascularization and the role and duration of antiplatelet and anticoagulant therapy in re-vascularized lower limb PAD patients.

Personalizing antiplatelet prescribing using genetics for patients undergoing percutaneous coronary intervention

INTRODUCTION

Clopidogrel is commonly prescribed with aspirin to reduce the risk for adverse cardiovascular events after percutaneous coronary intervention (PCI). However, there is significant inter-patient variability in clopidogrel response. The CYP2C19 enzyme is involved in the biotransformation of clopidogrel to its pharmacologically active form, and variation in the CYP2C19 gene contributes to clopidogrel response variability. Areas covered. This article describes the impact of CYP2C19 genotype on clopidogrel pharmacokinetics, pharmacodynamics, and effectiveness. Examples of clinical implementation of CYP2C19 genotype-guided antiplatelet therapy for patients undergoing PCI are also described as are emerging outcomes data with this treatment approach. Expert commentary. A large clinical trial evaluating outcomes with CYP2C19 genotype-guided antiplatelet therapy after PCI is on-going. In the meantime, data from pragmatic and observational studies and smaller trials support improved outcomes with genotyping after PCI and use of alternative antiplatelet therapy in patients with a CYP2C19 genotype associated with reduced clopidogrel effectiveness.

[Antiplatelet therapy in patient undergoing angioplasty for peripheral artery disease]

Antiplatelet therapy in patients undergoing PTA/Stenting for PAD relies on low quality evidences. Most interventionists provide a loading dose of clopidogrel in addition to aspirin followed by dual antiplatelet therapy for a duration of 1 to 3 months after PTA. The rational of this strategy relies mostly on the results of studies dedicated to coronary angioplasty. Ongoing trials with direct oral anticoagulants will perhaps provide new data in order to improve the practice.

Advances in Clinical Cardiology 2016: A Summary of the Key Clinical Trials

INTRODUCTION

The findings of many new cardiology clinical trials over the last year have been published or presented at major international meetings. This paper aims to describe and place in context a summary of the key clinical trials in cardiology presented between January and December 2016.

METHODS

The authors reviewed clinical trials presented at major cardiology conferences during 2016 including the American College of Cardiology (ACC), European Association for Percutaneous Cardiovascular Interventions (EuroPCR), European Society of Cardiology (ESC), European Association for the Study of Diabetes (EASD), Transcatheter Cardiovascular Therapeutics (TCT), and the American Heart Association (AHA). Selection criteria were trials with a broad relevance to the cardiology community and those with potential to change current practice.

RESULTS

A total of 57 key cardiology clinical trials were identified for inclusion. Here we describe and place in clinical context the key findings of new data relating to interventional and structural cardiology including delayed stenting following primary angioplasty, contrast-induced nephropathy, management of jailed wires, optimal duration of dual antiplatelet therapy (DAPT), stenting vs bypass for left main disease, new generation stents (BioFreedom, Orsiro, Absorb), transcatheter aortic valve implantation (Edwards Sapien XT, transcatheter embolic protection), and closure devices (Watchman, Amplatzer). New preventative cardiology data include trials of bariatric surgery, empagliflozin, liraglutide, semaglutide, PCSK9 inhibitors (evolocumab and alirocumab), and inclisiran. Antiplatelet therapy trials include platelet function monitoring and ticagrelor vs clopidogrel for peripheral vascular disease. New data are also presented in fields of heart failure (sacubitril/valsartan, aliskiren, spironolactone), atrial fibrillation (rivaroxaban in patients undergoing coronary intervention, edoxaban in DC cardioversion), cardiac devices (implantable cardioverter defibrillator in non-ischemic cardiomyopathy), and electrophysiology (cryoballoon vs radiofrequency ablation).

CONCLUSION

This paper presents a summary of key clinical cardiology trials during the past year and should be of practical value to both clinicians and cardiology researchers.

Role for Thrombin Receptor Antagonism With Vorapaxar in Secondary Prevention of Atherothrombotic Events: From Bench to Bedside

In spite of treatment with the current standard of care antiplatelet regimens including dual antiplatelet therapy, recurrence rates of ischemic events remain elevated for high-risk patients with atherosclerotic disease. This may be in part attributed to the fact that other key platelet activation pathways remain uninhibited and can thus continue to trigger platelet activation and lead to thrombotic complications. Thrombin is a powerful inducer of platelet activation and mediates its effects directly on platelets through protease activator receptors (PARs), particularly the PAR-1 subtype, making PAR-1 inhibition an attractive approach for reducing atherothrombotic events. These observations have led to the development of several PAR-1 antagonists. Vorapaxar is a direct inhibitor of PAR-1 and the only agent of this class approved for the prevention of recurrent ischemic events in patients with prior myocardial infarction or peripheral artery disease. In the present manuscript, we present a review of the pathophysiologic role of thrombin on thrombotic complications, the impact of vorapaxar on outcomes, including the most recent updates deriving from clinical trials, as well as future perspectives in the field.

Medical management of claudication

Peripheral artery disease (PAD) is common and associated with significant morbidity and mortality. Optimal medical management of PAD is required for each patient, irrespective of the decision regarding lower extremity revascularization. The goals include reducing cardiovascular morbidity and mortality and improving quality of life. The approach should consist of aggressive and individualized risk factor modification including smoking cessation, antiplatelet therapy, a statin, and an angiotensin-converting enzyme inhibitor. Exercise is critical for cardiovascular health and highly effective for improving claudication symptoms. Cilostazol may be considered for symptomatic treatment in certain patients.

Geographic variation and risk factors for systemic and limb ischemic events in patients with symptomatic peripheral artery disease: Insights from the REACH Registry

Background

Patients with symptomatic peripheral artery disease (PAD) are at high risk of ischemic events. However, data about predictors of this risk are limited.

Hypothesis

We analyzed baseline characteristics and 4‐year follow‐up of patients enrolled in the international REduction of Atherothrombosis for Continued Health (REACH) Registry with symptomatic PAD and no history of stroke/transient ischemic attack to describe annual rates of recurrent ischemic events globally and geographically.

Methods

The primary outcome was systemic ischemic events (composite of cardiovascular death, myocardial infarction, or stroke) at 4 years. The secondary outcome was limb ischemic events (composite of lower limb amputation, peripheral bypass graft, and percutaneous intervention for PAD) at 2 years. Multivariate analysis identified risk factors associated with recurrent ischemic events.

Results

The primary endpoint rate reached 4.7% during the first year and increased continuously (by 4%–5% each year) to 17.6% by year 4, driven mainly by cardiovascular mortality (11.1% at year 4). Japan experienced lower adjusted ischemic rates (P < 0.01) vs North America. Renal impairment (P < 0.01), congestive heart failure (P < 0.01), history of diabetes (P < 0.01), history of myocardial infarction (P = 0.01), vascular disease (single or poly, P < 0.01), and older age (P < 0.01) were associated with increased risk of systemic ischemic events, whereas statin use was associated with lower risk (P = 0.03). The limb ischemic event rate was 5.7% at 2 years.

Conclusions

Four‐year systemic ischemic risk in patients with PAD and no history of stroke or transient ischemic attack remains high, and was mainly driven by cardiovascular mortality.

Ticagrelor therapy and atrioventricular block: Do we need to worry?

Ticagrelor is a potent, direct P2Y12 antagonist with rapid onset of action and intense platelet inhibition, indicated in patients with acute coronary syndromes (ACS). This drug is usually well tolerated, but some patients experience serious adverse effects: Major bleeding; gastrointestinal disturbances; dyspnoea; ventricular pauses > 3 s. Given the unexpected high incidence of bradyarrhythmias, a PLATO substudy monitored this side effect, showing that ticagrelor was associated with an increase in the rate of sinus bradycardia and sinus arrest compared to clopidogrel. This side effect was usually transient, asymptomatic and not associated with higher incidence of severe atrioventricular (AV) block or pacemaker needs. A panel of experts from Food and Drug Administration did not consider bradyarrhythmias a serious problem in clinical practice and, accordingly, current labeling of the drug does not give any precaution or contraindication regarding this issue. However, recently some articles have described ACS patients with high-degree, life-threatening, AV block requiring drug discontinuation and, in some cases, pacemaker implantation. In this paper, we describe and discuss five published case reports of severe AV block following ticagrelor therapy and two other cases managed in our Hospital. The analysis of literature suggests that, although rarely, ticagrelor can be associated with life-threatening AV block. Caution and careful monitoring are required especially in patients with already compromised conduction system and/or treated with AV blocking agents. Future studies, with long-term rhythm monitoring, would help to define the outcome of patients at higher risk of developing this complication.

Platelet Reactivity and Clinical Outcomes After Coronary Artery Implantation of Drug-Eluting Stents in Subjects With Peripheral Arterial Disease: Analysis From the ADAPT-DES Study (Assessment of Dual Antiplatelet Therapy With Drug-Eluting Stents)

BACKGROUND

Patients with peripheral arterial disease (PAD) have high rates of adverse cardiovascular events after percutaneous coronary intervention and may additionally have heightened platelet reactivity. This study assessed the relationship between platelet reactivity and clinical outcomes after percutaneous coronary interventions among subjects with and without PAD.

METHODS AND RESULTS

ADAPT-DES (Assessment of Dual Antiplatelet Therapy With Drug-Eluting Stents) was a prospective, multicenter registry of patients treated with coronary drug-eluting stents. Platelet reactivity was assessed by the VerifyNow point-of-care assay; high on-treatment platelet reactivity (HPR) was defined as P2Y12 reaction units >208. A propensity-adjusted multivariable analysis was performed to determine the relationship between PAD, platelet reactivity, and subsequent adverse events (definite or probable stent thrombosis, all-cause mortality, myocardial infarction, and clinically relevant bleeding). Among 8582 patients, 10.2% had a history of PAD. Patients with PAD were older and more likely to have comorbid conditions; however, mean P2Y12 reaction units and HPR were not significantly different between PAD and no PAD groups. Patients with PAD had higher 2-year rates of all-cause mortality, myocardial infarction, stent thrombosis, and clinically relevant bleeding. Associations between HPR and adverse events were similar in PAD and no PAD groups, without evidence of interaction; however, adverse event rates were highest among subjects with both PAD and HPR. In a propensity-adjusted multivariable model, both PAD and HPR were independent predictors of myocardial infarction at 2 years.

CONCLUSIONS

A history of PAD was associated with ischemic and bleeding outcomes 2 years after successful coronary drug-eluting stent implantation; however, these associations did not seem to be directly mediated by heightened platelet reactivity.

CLINICAL TRIAL REGISTRATION

URL: http://www.clinicaltrials.gov. Unique identifier: NCT00638794.