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Variability and persistence of aspirin response in lower extremity peripheral arterial disease patients.

ABSTRACT: To determine the prevalence of poor response to aspirin (ASA) therapy over 12-month follow-up in patients with lower extremity peripheral arterial disease (PAD), and to compare the classification agreement among different ASA response assays.Patients with PAD on ASA therapy at baseline were included from the ongoing Effect of Lipid Modification on Peripheral Arterial Disease after Endovascular Intervention Trial (ELIMIT), which is a randomized trial testing whether combination treatment with ezetimibe, niacin, and a statin will halt/regress atherosclerosis compared with statin monotherapy. Patients who had baseline platelet testing and repeat testing at 6-month or 12-month follow-up were included. ASA responsiveness was tested using three different assays: Optical aggregation with 0.5 mg/mL of arachidonic acid (AA), optical aggregation with 10 ?M of adenosine diphosphate (ADP), and platelet function analyzer-100 (PFA-100) testing with collagen/epinephrine (Epi) loaded cartridges. ASA response was defined as AA aggregation <30%, ADP aggregation <70%, or PFA-100 Epi >164 seconds. Patients who showed response to ASA at baseline were classified as Responders. Poor response to ASA was defined as AA aggregation ? 30%, ADP aggregation ? 70%, or PFA-100 Epi ? 164 seconds. Patients who showed poor response (PR) to an assay at baseline, but then were responsive at follow-up visits were classified as Initial PRs. Patients who showed poor response at baseline and all follow-up visits were classified as Persistent PRs. The classification agreement between assays was tested using the kappa statistic.Of 102 patients randomized in ELIMIT, 80 patients satisfied inclusion criteria. There were no significant baseline demographic differences between Responders, Initial PRs, and Persistent PRs. The prevalence of persistent poor response varied by the assay used; 5% of subjects (4/80) were Persistent PRs by AA aggregation, compared with 27.5% (22/80) of subjects by ADP aggregation and 9.9% (7/71) of patients by PFA-100 Epi. Regarding the agreement of the assays, only AA aggregation and PFA-100 Epi agreed significantly (K = 0.3223; 95% confidence interval [CI] 0.15-0.493; P = .0001), and though statistically significant, the magnitude of this agreement is small. AA aggregation and ADP aggregation did not agree (K = 0.1161; 95% CI -0.004-0.236; P = .029), nor did ADP aggregation and PFA-100 Epi (K = 0.0044; 95% CI -0.151-0.160; P = .48).Between 5% and 27.5% of PAD patients were Persistent PRs to ASA over 6- to 12-month follow-up using different platelet assays. Further, these commonly used platelet assays show weak agreement in determining poor response to aspirin.

SUBMITTER: Saunders J

PROVIDER: S-EPMC3197816 | biostudies-literature | 2011 Mar

REPOSITORIES: biostudies-literature

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Variability and persistence of aspirin response in lower extremity peripheral arterial disease patients.

Saunders Justin J Nambi Vijay V Kimball Kay T KT Virani Salim S SS Morrisett Joel D JD Lumsden Alan B AB Ballantyne Christie M CM Dong Jing-Fei JF

Journal of vascular surgery 20110112 3

<h4>Objective</h4>To determine the prevalence of poor response to aspirin (ASA) therapy over 12-month follow-up in patients with lower extremity peripheral arterial disease (PAD), and to compare the classification agreement among different ASA response assays.<h4>Methods</h4>Patients with PAD on ASA therapy at baseline were included from the ongoing Effect of Lipid Modification on Peripheral Arterial Disease after Endovascular Intervention Trial (ELIMIT), which is a randomized trial testing whet ...[more]

PMID: 21227624

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Project description:ImportancePatients with symptomatic lower extremity peripheral artery disease (LE-PAD) experience an increased risk of major vascular events. There is limited information on what clinical features of symptomatic LE-PAD prognosticate major vascular events and whether patients at high risk have a greater absolute benefit from low-dose rivaroxaban and aspirin.ObjectiveTo quantify the risk of major vascular events and investigate the response to treatment with low-dose rivaroxaban and aspirin among patients with symptomatic LE-PAD based on clinical presentation and comorbidities.Design, setting, and participantsThis is a subanalysis of a previously reported subgroup of patients with symptomatic LE-PAD who were enrolled in a large, double-blind, placebo-controlled randomized clinical trial (Cardiovascular Outcomes for People Using Anticoagulation Strategies [COMPASS]) in 602 centers in 33 countries from March 2013 to January 2020. Data analysis was completed from May 2016 to June 2020.InterventionsA combination of low-dose rivaroxaban and aspirin compared with aspirin alone.Main outcomes and measuresThirty-month incidence risk of myocardial infarction, stroke and cardiovascular death (MACE), major adverse limb events (MALE) including major vascular amputation, and bleeding.ResultsThe COMPASS trial enrolled 4129 patients with symptomatic LE-PAD (mean [SD] age, 66.8 [8.8] years; 2932 men [71.0%]). The 30-month Kaplan-Meier incidence risk of MACE or MALE, including major amputation, was 22.6% in those with prior amputation (this outcome was observed in 54 patients), 17.6% (n = 15) in those with Fontaine III or IV symptoms, and 11.8% (n = 142) in those with previous peripheral artery revascularization, classifying these features as high-risk limb presentations. The 30-month incidence risk of MACE or MALE, including major amputation, was 14.1% (n = 118) in those with kidney dysfunction, 13.5% (n = 67) in those with heart failure, 13.4% (n = 199) in those with diabetes, and 12.8% (n = 222) in those with polyvascular disease, classifying these features as high-risk comorbidities. Among patients with either high-risk limb presentations or high-risk comorbidities, treatment with rivaroxaban and aspirin compared with aspirin alone was associated with an estimated 4.2% (95% CI, 1.9%-6.2%) absolute risk reduction for MACE or MALE, including major amputation, at 30 months. Although the estimated absolute risk increase of major bleeding was higher with rivaroxaban and aspirin in combination than aspirin alone (2.0% [95% CI, 0.5%-3.9%]) for patients with either high-risk limb presentation or high-risk comorbidity, the estimated absolute risk increase of fatal or critical organ bleeding was low in this high-risk group (0.4% [95% CI, 0.2%-1.8%]), such that the net clinical benefit was estimated to be 3.2% (95% CI, 0.6%-5.3%).Conclusions and relevancePatients with LE-PAD with high-risk limb presentations or high-risk comorbidities had a high incidence of major vascular events. For these patients, treatment with rivaroxaban and aspirin in combination compared with aspirin alone led to a large absolute reduction in vascular risk.

Project description:Prior studies have suggested treatment and outcome disparities between men and women for lower extremity peripheral arterial disease after surgical bypass. Given the recent shift toward endovascular therapy, which has increasingly been used to treat claudication, we sought to analyze sex disparities in presentation, revascularization, amputation, and inpatient mortality.We identified individuals with intermittent claudication and critical limb ischemia (CLI) using International Classification of Diseases, Ninth Revision codes in the Nationwide Inpatient Sample from 1998 to 2009. We compared presentation at time of intervention (intermittent claudication vs CLI), procedure (open surgery vs percutaneous transluminal angioplasty or stenting vs major amputation), and in-hospital mortality for men and women. Regional and ambulatory trends were evaluated by performing a separate analysis of the State Inpatient and Ambulatory Surgery Databases from four geographically diverse states: California, Florida, Maryland, and New Jersey.From the Nationwide Inpatient Sample, we identified 1,797,885 patients (56% male) with intermittent claudication (26%) and CLI (74%), who underwent 1,865,999 procedures (41% open surgery, 20% percutaneous transluminal angioplasty or stenting, and 24% amputation). Women were older at the time of intervention by 3.5 years on average and more likely to present with CLI (75.9% vs 72.3%; odds ratio [OR], 1.21; 95% confidence interval [CI], 1.21-1.23; P < .01). Women were more likely to undergo endovascular procedures for both intermittent claudication (47% vs 41%; OR, 1.27; 95% CI, 1.25-1.28; P < .01) and CLI (21% vs 19%; OR, 1.14; 95% CI, 1.13-1.15; P < .01). From 1998 to 2009, major amputations declined from 18 to 11 per 100,000 in men and 16 to 7 per 100,000 in women, predating an increase in total CLI revascularization procedures that was seen starting in 2005 for both men and women. In-hospital mortality was higher in women regardless of disease severity or procedure performed even after adjusting for age and baseline comorbidities (.5% vs .2% after percutaneous transluminal angioplasty or stenting for intermittent claudication; 1.0% vs .7% after open surgery for intermittent claudication; 2.3% vs 1.6% after percutaneous transluminal angioplasty or stenting for CLI; 2.7% vs 2.2% after open surgery for CLI; P < .01 for all comparisons).There appears to be a preference to perform endovascular over surgical revascularization among women, who are older and have more advanced disease at presentation. Percutaneous transluminal angioplasty or stenting continues to be popular and is increasingly being performed in the outpatient setting. Amputation and in-hospital mortality rates have been declining, and women now have lower amputation but higher mortality rates than men. Recent improvements in outcomes are likely the result of a combination of improved medical management and risk factor reduction.

Project description:IntroductionPatients with peripheral arterial disease (PAD) are at increased risk for systemic arterial thromboembolic events. Females represent a unique subset of patients with PAD, who differ from males in important ways: they have smaller diameter vessels, undergo lower extremity bypass less frequently and experience higher rates of graft occlusion, amputation and mortality than males. Females also trend towards higher rates of major coronary events and cardiovascular mortality. Current guidelines recommend monoantiplatelet therapy (MAPT) for secondary prevention in patients with symptomatic PAD. However, indications for more intensive antithrombotic therapy in this cohort-especially among females who are frequently under-represented in randomised controlled trials (RCTs)-remain unclear. As newer antithrombotic therapies emerge, some RCTs have demonstrated differential effects in females versus males. A systematic review is needed to quantify the rates of arterial thromboembolic and bleeding events with different antithrombotic regimens in females with symptomatic PAD.Methods and analysisWe will search MEDLINE, Embase and the Cochrane Central Register of Controlled trials for published RCTs that include females with symptomatic PAD and compare full dose anticoagulation±antiplatelet therapy, dual pathway inhibition or dual antiplatelet therapy with MAPT. Title, abstract and full-text screening will be conducted in duplicate by three reviewers. Authors will be contacted to obtain sex-stratified outcomes as needed. Risk of bias will be assessed using the Cochrane Risk of Bias tool. Data will be extracted by independent reviewers and confirmed by a second reviewer. Quantitative synthesis will be conducted using Review Manager (RevMan) V.5 for applicable outcomes data. Planned subgroup analysis by PAD severity, vascular intervention and indication for antithrombotics will be conducted where data permits.Ethics and disseminationEthics approval is waived as the study does not involve primary data collection. This review will be submitted for publication in a peer-reviewed journal and for presentation at national and international scientific meetings.Trial registration numberThis protocol was registered with the PROSPERO International Prospective Register of Systematic Reviews (ID# CRD42020196933).

Dataset Information

Variability and persistence of aspirin response in lower extremity peripheral arterial disease patients.

Publications

Variability and persistence of aspirin response in lower extremity peripheral arterial disease patients.

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