Etiology and outcomes of amputation in patients with peripheral artery disease in the EUCLID trial.

OBJECTIVE: Amputation remains a frequent and feared outcome in patients with peripheral artery disease (PAD). Although typically characterized as major or minor on the extent of tissue loss, the etiologies and outcomes after amputation by extent are not well-understood. In addition, emerging data suggest that the drivers and outcomes of amputation in patients with PAD may differ in those with and without diabetes mellitus (DM). METHODS: The EUCLID trial randomized 13,885 patients with symptomatic PAD, including 5345 with concomitant diabetes, to ticagrelor or clopidogrel and followed them for long-term outcomes. Amputations were prospectively reported by trial investigators. Their primary and contributing drivers were adjudicated using safety data, including infection, ischemia, or multifactorial etiologies. Outcomes following major and minor amputations were analyzed, including recurrent amputation, major adverse limb events, adverse cardiovascular events, and mortality. Multivariable logistic regression models were used to identify independent predictors of minor amputations. Analyses were performed overall and stratified by the presence or absence of DM at baseline. RESULTS: Of the patients randomized, 398 (2.9%) underwent at least one lower extremity nontraumatic amputation, for a total of 511 amputations (255 major and 256 minor) over a median of 30 months. A history of minor amputation was the strongest independent predictor for a subsequent minor amputation (odds ratio, 7.29; 95% confidence interval, 5.17-10.30; P < .001) followed by comorbid DM (odds ratio, 4.60; 95% confidence interval, 3.16-6.69; P < .001). Compared with patients who had a major amputation, those with a minor amputation had similar rates of subsequent major amputation (12.2% vs 13.6%), major adverse limb events (15.1% vs 14.9%), and major adverse cardiovascular events (17.6% vs 16.3%). Ischemia alone was the primary driver of amputation (51%), followed by infection alone (27%), and multifactorial etiologies (22%); however, infection was the most frequent driver in those with DM (58%) but not in those without DM (15%). CONCLUSIONS: Outcomes after amputation remain poor regardless of whether they are categorized as major or minor. The pattern of amputation drivers in PAD differs by history of DM, with infection being the dominant etiology in those with DM and ischemia in those without DM. Greater focus is needed on the prognostic importance of minor amputation and of the multifactorial etiologies of amputation in PAD. Nomenclature with anatomical description of amputations and eliminating terms "major" or "minor" would seem appropriate.

World regional differences in outcomes for patients with peripheral artery disease: Insights from the EUCLID trial.

Regional variations exist in the epidemiology of peripheral artery disease (PAD), in comorbidities, use of secondary prevention, and outcomes. Large studies of these variations in worldwide populations are rare. The EUCLID (Examining Use of tiCagreLor In peripheral artery Disease) trial included 13,885 patients with PAD from four geographical regions (Central/South America, Europe, Asia, North America) and compared monotherapy with ticagrelor and clopidogrel. Inclusion criteria were either an ankle-brachial index < 0.80 or a prior revascularization. The primary efficacy endpoint was time to first occurrence of any event in the composite of cardiovascular death, myocardial infarction, or ischemic stroke and did not differ between the study arms. This post hoc analysis of EUCLID confirmed that regional differences occurred in the inclusion criteria with more prior revascularization in North America (73.9%) and Asia (72.5%) compared with Central/South America (34.0%) and Europe (51.6%). The characteristics of patients also differed. Prior amputation at baseline was most frequent in Central/South America (6.3%) compared with other regions (1.6-2.8%). A history of stroke was most common in Asia, coronary heart disease in North America, and diabetes in Central/South America compared with other regions. The incidence of outcomes in patients with PAD varied by region. North America had the highest rate of the primary combined endpoint (5.97 events/100 patient-years). Corresponding rates were 4.80, 3.95, and 3.87 for Asia, Europe, and Central/South America, respectively. Hospitalization for acute limb ischemia (events/100 patient-years) was most frequent in Europe (0.75) and North America (0.74) compared with Asia (0.60) and Central/South America (0.33). Adjustment for inclusion criteria and relevant PAD characteristics did not have a major impact on these regional differences. Further adjustment for concomitant disease, risk factors, and preventive medication modified the regional differences only marginally. In conclusion, substantial regional differences were found in cardiovascular and limb outcomes in patients with PAD and were not explained by variation in the category of included patients, concomitant disease, risk factors, and prevention. Such differences, which may be due to variation in other factors such as background population rates or clinical care, need to be considered when designing and interpreting large international studies (ClinicalTrials.gov Identifier: NCT01732822).

Acute Limb Ischemia in Peripheral Artery Disease.

BACKGROUND: Acute limb ischemia (ALI) is an important clinical event and an emerging cardiovascular clinical trial outcome. Risk factors for and outcomes after ALI have not been fully evaluated. METHODS: EUCLID (Examining Use of Ticagrelor in Peripheral Artery Disease) randomized patients with peripheral artery disease to ticagrelor versus clopidogrel. Enrollment criteria included an ankle-brachial index ≤0.80 or previous lower extremity revascularization. Patients were grouped according to the primary outcome, postrandomization ALI hospitalization. Baseline factors associated with ALI were identified using Cox proportional hazards modeling. Models with ALI hospitalization as a time-dependent covariate were developed for secondary outcomes of major adverse cardiovascular events (myocardial infarction, cardiovascular death, ischemic stroke), all-cause mortality, and major amputation. RESULTS: Among 13 885 patients, 1.7% (n=232) had 293 ALI hospitalizations (0.8 per 100 patient-years). Patients with versus without ALI were younger and more often had previous peripheral revascularization and lower baseline ankle-brachial index. Treatment during ALI hospitalization included endovascular revascularization (39.2%, n=115), surgical bypass (24.6%, n=72), and major amputation (13.0%, n=38). After multivariable adjustment, any previous peripheral revascularization (Hazard Ratio [HR] 4.7, 95% CI 3.3-6.8, P<0.01), baseline atrial fibrillation (HR 1.8, 95% CI 1.1-3.2, P=0.03), and baseline ankle-brachial index ≤0.60 (HR 1.3 per 0.10 decrease, 95% CI 1.1-1.5, P<0.01) were associated with higher ALI risk. Older age (HR 0.8 per 10-year increase, 95% CI 0.7-1.0, P=0.02) and baseline statin use (HR 0.7, 95% CI 0.5-0.9, P<0.01) were associated with lower risk for ALI. There was no relationship between randomized treatment to ticagrelor or clopidogrel and ALI. Among patients with previous revascularization, surgical versus endovascular procedures performed more than 6 months prior were associated with ALI (adjusted HR 2.63, 95% CI 1.75-3.96). In the overall population, ALI hospitalization was associated with subsequent MACE (adjusted HR 1.4, 95% CI 1.0-2.1, P=0.04), all-cause mortality (adjusted HR 3.3, 95% CI 2.4-4.6, P<0.01), and major amputation (adjusted HR 34.2, 95% CI 9.7-20.8, P<0.01). CONCLUSIONS: Previous peripheral revascularization, baseline atrial fibrillation, and lower ankle-brachial index identify peripheral artery disease patients at heightened risk for ALI, an event associated with subsequent cardiovascular and limb-related morbidity and mortality. CLINICAL TRIAL REGISTRATION: URL: https://www.clinicaltrials.gov. Unique identifier: NCT01732822.

Ticagrelor versus Clopidogrel in Symptomatic Peripheral Artery Disease.

BACKGROUND: Peripheral artery disease is considered to be a manifestation of systemic atherosclerosis with associated adverse cardiovascular and limb events. Data from previous trials have suggested that patients receiving clopidogrel monotherapy had a lower risk of cardiovascular events than those receiving aspirin. We wanted to compare clopidogrel with ticagrelor, a potent antiplatelet agent, in patients with peripheral artery disease. METHODS: In this double-blind, event-driven trial, we randomly assigned 13,885 patients with symptomatic peripheral artery disease to receive monotherapy with ticagrelor (90 mg twice daily) or clopidogrel (75 mg once daily). Patients were eligible if they had an ankle-brachial index (ABI) of 0.80 or less or had undergone previous revascularization of the lower limbs. The primary efficacy end point was a composite of adjudicated cardiovascular death, myocardial infarction, or ischemic stroke. The primary safety end point was major bleeding. The median follow-up was 30 months. RESULTS: The median age of the patients was 66 years, and 72% were men; 43% were enrolled on the basis of the ABI and 57% on the basis of previous revascularization. The mean baseline ABI in all patients was 0.71, 76.6% of the patients had claudication, and 4.6% had critical limb ischemia. The primary efficacy end point occurred in 751 of 6930 patients (10.8%) receiving ticagrelor and in 740 of 6955 (10.6%) receiving clopidogrel (hazard ratio, 1.02; 95% confidence interval [CI], 0.92 to 1.13; P=0.65). In each group, acute limb ischemia occurred in 1.7% of the patients (hazard ratio, 1.03; 95% CI, 0.79 to 1.33; P=0.85) and major bleeding in 1.6% (hazard ratio, 1.10; 95% CI, 0.84 to 1.43; P=0.49). CONCLUSIONS: In patients with symptomatic peripheral artery disease, ticagrelor was not shown to be superior to clopidogrel for the reduction of cardiovascular events. Major bleeding occurred at similar rates among the patients in the two trial groups. (Funded by AstraZeneca; EUCLID ClinicalTrials.gov number, NCT01732822 .).

Major bleeding in patients with peripheral artery disease: Insights from the EUCLID trial.

BACKGROUND: Rates and predictors of major bleeding in patients with peripheral artery disease (PAD) treated with antiplatelets have not been well studied. This post hoc analysis of EUCLID aimed to determine the incidence of major/minor bleeding, predictors of major bleeding, and risk of major adverse cardiovascular events (MACE) following major bleeding events. METHODS: EUCLID, a multicenter randomized controlled trial of 13,885 patients with symptomatic PAD, compared ticagrelor with clopidogrel for the prevention of MACE. The primary safety end point was Thrombolysis in Myocardial Infarction (TIMI) major bleeding. Baseline characteristics were used to develop a multivariable model to determine factors associated with TIMI major bleeding. The occurrence and timing of MACE relative to a first major bleeding event were determined. RESULTS: TIMI major bleeding occurred in 2.3% of participants overall (0.94 event/100 patient-years). There was no significant difference in major bleeding rates by treatment assignment. Factors associated with TIMI major bleeding included older age, geographic region, Rutherford class, and ß-blocker use. Patients with TIMI major bleeding postrandomization had an increased risk of MACE (hazard ratio [HR] 4.46; 95% CI 3.40-5.84; P < .0001) compared with those without major bleeding; the association was strongest within 30 days after a bleeding event. CONCLUSIONS: In patients with symptomatic PAD, 0.94 major bleeding event/100 patient-years was observed and associated with older age, residing in North America, disease severity, and ß-blocker use. Patients who had a major bleeding event were significantly more likely to experience MACE, especially within the first 30 days, when compared with patients who did not have major bleeding.

Stroke in Patients With Peripheral Artery Disease.

Background and Purpose- Predictors of stroke and transient ischemic attack (TIA) in patients with peripheral artery disease (PAD) are poorly understood. The primary aims of this analysis were to (1) determine the incidence of ischemic/hemorrhagic stroke and TIA in patients with symptomatic PAD, (2) identify predictors of stroke in patients with PAD, and (3) compare the rate of stroke in ticagrelor- and clopidogrel-treated patients. Methods- EUCLID (Examining Use of Ticagrelor in Peripheral Artery Disease) randomized 13 885 patients with symptomatic PAD to receive monotherapy with ticagrelor or clopidogrel for the prevention of major adverse cardiovascular events (cardiovascular death, myocardial infarction, or ischemic stroke). Ischemic/hemorrhagic stroke and TIA were adjudicated and measured as incidence rates postrandomization and cumulative incidence (per patient-years). Post hoc multivariable competing risk hazards analyses were performed using baseline characteristics to determine factors associated with all-cause stroke in patients with PAD. Results- A total of 458 cerebrovascular events in 424 patients (317 ischemic strokes, 39 hemorrhagic strokes, and 102 TIAs) occurred over a median follow-up of 30 months, for a cumulative incidence of 0.87, 0.11, and 0.27 per 100 patient-years, respectively. Age, prior stroke, prior atrial fibrillation/flutter, diabetes mellitus, geographic region, ankle-brachial index <0.60, prior amputation, and systolic blood pressure were independent baseline factors associated with the occurrence of all-cause stroke. After adjustment for baseline factors, the rates of ischemic stroke and all-cause stroke remained lower in patients treated with ticagrelor as compared with those receiving clopidogrel. There was no significant difference in the incidence of hemorrhagic stroke or TIA between the 2 treatment groups. Conclusions- In patients with symptomatic PAD, ischemic stroke and TIA occur frequently over time. Comorbidities such as age, prior stroke, prior atrial fibrillation/flutter, diabetes mellitus, higher blood pressure, prior amputation, lower ankle-brachial index, and geographic region were each independently associated with the occurrence of all-cause stroke. Use of ticagrelor, as compared with clopidogrel, was associated with a lower adjusted rate of ischemic and all-cause stroke. Further study is needed to optimize medical management and risk reduction of all-cause stroke in patients with PAD. Clinical Trial Registration- URL: https://www.clinicaltrials.gov . Unique identifier: NCT01732822.

Chronic kidney disease and risk for cardiovascular and limb outcomes in patients with symptomatic peripheral artery disease: The EUCLID trial.

In patients with symptomatic peripheral artery disease (PAD), the impact of chronic kidney disease (CKD) on major adverse cardiovascular events has not been fully evaluated. The Examining Use of Ticagrelor In PAD (EUCLID) trial randomized 13,885 patients with PAD to ticagrelor 90 mg twice daily or clopidogrel 75 mg daily. This post hoc analysis compared the incidence of the primary composite endpoint (cardiovascular death, myocardial infarction (MI), or ischemic stroke) in patients with CKD (eGFR < 60 mL/min/1.73 m2) with those without CKD (eGFR ⩾ 60 mL/min/1.73 m2). The primary safety endpoint was thrombolysis in MI (TIMI) major bleeding. A total of 13,483 patients were included; 3332 (25%) had CKD, of whom 237 had stage 4/5 disease. Median follow-up was approximately 30 months. After statistical adjustment, patients with CKD had a higher rate of the primary endpoint compared with those without CKD (6.75 vs 3.72 events/100 patient-years; adjusted hazard ratio (HR) 1.45, 95% CI 1.30-1.63). CKD was not associated with increased risk of hospitalization for acute limb ischemia (ALI) (adjusted HR 0.96, 95% CI 0.69-1.34) or major amputation (adjusted HR 0.92, 95% CI 0.66-1.28). CKD was not associated with a significantly increased risk of major bleeding (adjusted HR 1.21, 95% CI 0.89-1.64), but minor bleeding was significantly increased (adjusted HR 1.51, 95% CI 1.07-2.15). In conclusion, patients with PAD and CKD had higher rates of cardiovascular death, MI, and ischemic stroke, but similar rates of ALI, major amputation, and TIMI major bleeding when compared with patients without CKD. ClinicalTrials.gov Identifier: NCT01732822.

A Structured Review of Antithrombotic Therapy in Peripheral Artery Disease With a Focus on Revascularization: A TASC (InterSociety Consensus for the Management of Peripheral Artery Disease) Initiative.

Peripheral artery disease affects >200 million people worldwide and is associated with significant limb and cardiovascular morbidity and mortality. Limb revascularization is recommended to improve function and quality of life for symptomatic patients with peripheral artery disease with intermittent claudication who have not responded to medical treatment. For patients with critical limb ischemia, the goals of revascularization are to relieve pain, help wound healing, and prevent limb loss. The baseline risk of cardiovascular and limb-related events demonstrated among patients with stable peripheral artery disease is elevated after revascularization and related to atherothrombosis and restenosis. Both of these processes involve platelet activation and the coagulation cascade, forming the basis for the use of antiplatelet and anticoagulant therapies to optimize procedural success and reduce postprocedural cardiovascular risk. Unfortunately, few high-quality, randomized data to support use of these therapies after peripheral artery disease revascularization exist, and much of the rationale for the use of antiplatelet agents after endovascular peripheral revascularization is extrapolated from percutaneous coronary intervention literature. Consequently, guideline recommendations for antithrombotic therapy after lower limb revascularization are inconsistent and not always evidence-based. In this context, the purpose of this structured review is to assess the available randomized data for antithrombotic therapy after peripheral arterial revascularization, with a focus on clinical trial design issues that may affect interpretation of study results, and highlight areas that require further investigation.

Ticagrelor Compared With Clopidogrel in Patients With Prior Lower Extremity Revascularization for Peripheral Artery Disease.

BACKGROUND: In patients with symptomatic peripheral artery disease with a history of limb revascularization, the optimal antithrombotic regimen for long-term management is unknown. METHODS: The EUCLID trial (Examining Use of Ticagrelor In PAD) randomized 13 885 patients with peripheral artery disease to treatment with ticagrelor 90 mg twice daily or clopidogrel 75 mg daily. Patients were enrolled based on an abnormal ankle-brachial index ≤0.80 or a previous lower extremity revascularization. This analysis focuses on the 7875 (57%) patients enrolled based on the previous lower extremity revascularization criterion. Patients could not be enrolled within 30 days of most recent revascularization, and patients with an indication for dual antiplatelet therapy were excluded. The primary efficacy end point was a composite of cardiovascular death, myocardial infarction, or ischemic stroke. The primary safety end point was major bleeding. RESULTS: Patients with a previous revascularization had a mean age of 66 years, 73% were male, and the median baseline ankle-brachial index was 0.78. After adjustment for baseline characteristics, patients enrolled based on previous revascularization had similar rates of the primary composite end point (hazard ratio [HR] 1.10, 95% confidence interval [CI] 0.98-1.23, P=0.12) and statistically significantly higher rates of myocardial infarction (HR 1.29, 95% CI 1.08-1.55, P=0.005) and acute limb ischemia (HR 4.23, 95% CI 2.86-6.25, P<0.001) when compared with patients enrolled based on ankle-brachial index criteria. No differences in ticagrelor- versus clopidogrel-treated patients were found for the primary efficacy end point (11.4% vs 11.3%; HR 1.01, 95% CI 0.88-1.15; P=0.90), all-cause mortality (9.2% vs 9.2%; HR 0.99, 95% CI 0.86-1.15; P=0.93), acute limb ischemia (2.5% vs 2.5%; HR 1.03, 95% CI 0.78-1.36; P=0.84), or major bleeding (1.9% vs 1.8%; HR 1.15, 95% CI 0.83-1.59; P=0.41). The median duration of follow-up was ≈30 months. CONCLUSIONS: After adjustment for baseline characteristics, patients enrolled based on previous revascularization for peripheral artery disease had higher rates of myocardial infarction and acute limb ischemia, with similar composite rates of cardiovascular death, myocardial infarction, and stroke when compared with patients enrolled based on the ankle-brachial index criterion. No significant differences were found between ticagrelor and clopidogrel for reduction of cardiovascular or acute limb events. CLINICAL TRIAL REGISTRATION: URL: http://www.clinicaltrials.gov. Unique identifier: NCT01732822.

Outcomes of Patients with Critical Limb Ischaemia in the EUCLID Trial.

OBJECTIVES: Critical limb ischaemia (CLI) implies an increased risk of cardiovascular morbidity and mortality, and the optimal antithrombotic treatment is not established. DESIGN, MATERIALS, METHODS: The EUCLID trial investigated the effect of monotherapy with ticagrelor versus clopidogrel in 13,885 patients with peripheral artery disease (PAD); the primary endpoint was cardiovascular death, myocardial infarction, or ischaemic stroke. Patients planned for revascularisation or amputation within 3 months, were excluded. This analysis focuses on the subgroup with CLI, defined by rest pain (58.8%), major (9.0%) or minor (32.2%) tissue loss. RESULTS: In EUCLID, 643 patients (4.6%) had CLI at baseline. Diabetes mellitus was more common in the CLI group, while coronary disease, carotid disease, and hypertension were more common in the non-CLI group. A majority of CLI patients (62.1%) had only lower extremity PAD. In patients enrolled on the ankle brachial index (ABI) criteria, ABI was 0.55 ± 0.21 (mean ± SD) for those with CLI versus 0.63 ± 0.15 for those without CLI. The primary efficacy endpoint significantly increased among patients with CLI compared with those without CLI with a rate of 8.85 versus 4.28/100 patient years (adjusted for baseline characteristics hazard ratio [HR] 1.43 [95% CI 1.16-1.76]; p = 0.0009). When acute limb ischaemia requiring hospitalisation was added to the model, significant differences remained (adjusted HR 1.38, [95% CI 1.13-1.69]; p = 0.0016). The 1 year mortality was 8.9%. A trend towards increased lower limb revascularisation among those with CLI was observed. Bleeding (TIMI major, fatal, intracranial) did not differ between those with and without CLI. CONCLUSIONS: Nearly 5% of patients enrolled in EUCLID had CLI at baseline. Milder forms of CLI dominated, a result of the trial design. Patients with CLI had a significantly higher rate of cardiovascular mortality and morbidity versus those without CLI. Further efforts are required to reduce the risk of cardiovascular events in PAD, especially in patients with CLI. CLINICALTRIALS.GOV: NCT01732822.

Ticagrelor versus clopidogrel in patients with symptomatic peripheral artery disease and prior coronary artery disease: Insights from the EUCLID trial.

Patients with peripheral artery disease (PAD) are at heightened risk of cardiovascular morbidity and mortality. We sought to evaluate the risk of concomitant coronary artery disease (CAD) in patients with symptomatic PAD versus PAD without diagnosed CAD, and whether ticagrelor was superior to clopidogrel in reducing that risk. The EUCLID trial randomized 13,885 patients with PAD to antithrombotic monotherapy with ticagrelor or clopidogrel. CAD was defined as prior myocardial infarction (MI), percutaneous coronary intervention (PCI), or coronary artery bypass graft (CABG) surgery. Median follow-up was 30 months. Among 4032 (29%) patients with PAD and CAD, 63% had prior MI, 54% prior PCI, and 38% prior CABG. After adjustment for baseline characteristics, patients with PAD and CAD had significantly higher rates of the primary endpoint (cardiovascular death/MI/stroke, 15.3% vs 8.9%, hazard ratio (HR) 1.50, 95% CI: 1.13-1.99; p=0.005), but no statistically significant increase in acute limb ischemia (HR 1.28, 95% CI: 0.57-2.85; p=0.55) or major bleeding (HR 1.10, 95% CI: 0.49-2.48; p=0.81) versus PAD without CAD. Among patients with PAD and CAD, there was no differential treatment effect between ticagrelor versus clopidogrel for the primary efficacy endpoint (HR 1.02, 95% CI: 0.87-1.19; p=0.84), acute limb ischemia (HR 1.03, 95% CI: 0.63-1.69; p=0.89), or major bleeding (HR 1.06, 95% CI: 0.66-1.69; p=0.81). There was a statistically significant interaction between prior coronary stent placement and study treatment ( p=0.03) with a numerical reduction in the primary efficacy endpoint with ticagrelor versus clopidogrel (13.8% vs 16.8%, HR 0.82, 95% CI: 0.65-1.03; p=0.09). Patients with PAD and prior CAD had higher composite rates of cardiovascular death, MI, and ischemic stroke versus PAD without diagnosed CAD. There were no significant differences between ticagrelor and clopidogrel in cardiovascular events or major bleeding. ClinicalTrials.gov Identifier: NCT01732822.

Design and rationale for the Effects of Ticagrelor and Clopidogrel in Patients with Peripheral Artery Disease (EUCLID) trial.

BACKGROUND: Despite overwhelming data demonstrating the efficacy of antiplatelet therapy in heart disease and stroke, data in peripheral artery disease (PAD) are less compelling. Aspirin has modest evidence supporting a reduction in cardiovascular events in patients with PAD, whereas clopidogrel monotherapy may be more effective in PAD. Ticagrelor, a potent, reversibly binding P2Y12 receptor antagonist, is beneficial in patients with acute coronary syndrome and prior myocardial infarction. The EUCLID trial is designed to address the need for effective antiplatelet therapy in PAD to decrease the risk of cardiovascular events. STUDY DESIGN: EUCLID is a randomized, double-blind, parallel-group, multinational clinical trial designed to evaluate the efficacy and safety of ticagrelor compared with clopidogrel for the prevention of major adverse cardiovascular events in subjects with symptomatic PAD. Subjects with established PAD will be randomized in a 1:1 fashion to ticagrelor 90 mg twice daily or clopidogrel 75 mg daily. The primary end point is a composite of cardiovascular death, myocardial infarction, or ischemic stroke. Other end points address limb events including acute leg ischemia, need for revascularization, disease progression by ankle-brachial index, and quality of life. The primary safety objective is Thrombolysis in Myocardial Infarction-defined major bleeding. Recruitment began in December 2012 and was completed in March 2014; 13,887 patients were randomized. The trial will continue until at least 1,364 adjudicated primary end points occur. CONCLUSIONS: The EUCLID study is investigating whether treatment with ticagrelor versus clopidogrel, given as antiplatelet monotherapy, will reduce the incidence of cardiovascular and limb-specific events in patients with symptomatic PAD.

C-reactive protein, fibrinogen, and cardiovascular disease prediction.

BACKGROUND: There is debate about the value of assessing levels of C-reactive protein (CRP) and other biomarkers of inflammation for the prediction of first cardiovascular events. METHODS: We analyzed data from 52 prospective studies that included 246,669 participants without a history of cardiovascular disease to investigate the value of adding CRP or fibrinogen levels to conventional risk factors for the prediction of cardiovascular risk. We calculated measures of discrimination and reclassification during follow-up and modeled the clinical implications of initiation of statin therapy after the assessment of CRP or fibrinogen. RESULTS: The addition of information on high-density lipoprotein cholesterol to a prognostic model for cardiovascular disease that included age, sex, smoking status, blood pressure, history of diabetes, and total cholesterol level increased the C-index, a measure of risk discrimination, by 0.0050. The further addition to this model of information on CRP or fibrinogen increased the C-index by 0.0039 and 0.0027, respectively (P<0.001), and yielded a net reclassification improvement of 1.52% and 0.83%, respectively, for the predicted 10-year risk categories of "low" (<10%), "intermediate" (10% to <20%), and "high" (≥20%) (P<0.02 for both comparisons). We estimated that among 100,000 adults 40 years of age or older, 15,025 persons would initially be classified as being at intermediate risk for a cardiovascular event if conventional risk factors alone were used to calculate risk. Assuming that statin therapy would be initiated in accordance with Adult Treatment Panel III guidelines (i.e., for persons with a predicted risk of ≥20% and for those with certain other risk factors, such as diabetes, irrespective of their 10-year predicted risk), additional targeted assessment of CRP or fibrinogen levels in the 13,199 remaining participants at intermediate risk could help prevent approximately 30 additional cardiovascular events over the course of 10 years. CONCLUSIONS: In a study of people without known cardiovascular disease, we estimated that under current treatment guidelines, assessment of the CRP or fibrinogen level in people at intermediate risk for a cardiovascular event could help prevent one additional event over a period of 10 years for every 400 to 500 people screened. (Funded by the British Heart Foundation and others.).

Smoking, hypercholesterolaemia and hypertension as risk factors for cognitive impairment in older adults.

BACKGROUND: the prevalence of all types of cognitive impairment, including dementia, is increasing but knowledge of aetiological factors is still evolving. OBJECTIVE: this study aimed to evaluate the association between cardiovascular risk factors and cognitive function in older persons. DESIGN, SETTING AND SUBJECTS: a population-based cohort design involving 2,312 men and women (aged 50-75) enrolled in the University of Edinburgh Aspirin for Asymptomatic Atherosclerosis trial. METHODS: cognitive tests included the Mill Hill Vocabulary Scale, auditory verbal learning test (AVLT), digit symbol test, verbal fluency test (VFT), Raven's Progressive Matrices and the trail making test. A 'g' score (measure of general intelligence) was computed for each subject. Regression analysis was used to evaluate the association between relevant variables. RESULTS: higher diastolic BP was negatively associated with AVLT (ß = -0.153, P < 0.01), and with an estimated decline on AVLT (ß = -0.125, P < 0.01). Smoking was negatively associated with all the cognitive variables except VFT. The total cholesterol level was not associated with cognitive function or estimated decline. CONCLUSIONS: smoking and elevated blood pressure may be risk factors for cognitive decline, and thus potential targets for preventive and therapeutic interventions.

Comparative analysis of genome-wide association studies signals for lipids, diabetes, and coronary heart disease: Cardiovascular Biomarker Genetics Collaboration.

AIMS: To evaluate the associations of emergent genome-wide-association study-derived coronary heart disease (CHD)-associated single nucleotide polymorphisms (SNPs) with established and emerging risk factors, and the association of genome-wide-association study-derived lipid-associated SNPs with other risk factors and CHD events. METHODS AND RESULTS: Using two case-control studies, three cross-sectional, and seven prospective studies with up to 25 000 individuals and 5794 CHD events we evaluated associations of 34 genome-wide-association study-identified SNPs with CHD risk and 16 CHD-associated risk factors or biomarkers. The Ch9p21 SNPs rs1333049 (OR 1.17; 95% confidence limits 1.11-1.24) and rs10757274 (OR 1.17; 1.09-1.26), MIA3 rs17465637 (OR 1.10; 1.04-1.15), Ch2q36 rs2943634 (OR 1.08; 1.03-1.14), APC rs383830 (OR 1.10; 1.02, 1.18), MTHFD1L rs6922269 (OR 1.10; 1.03, 1.16), CXCL12 rs501120 (OR 1.12; 1.04, 1.20), and SMAD3 rs17228212 (OR 1.11; 1.05, 1.17) were all associated with CHD risk, but not with the CHD biomarkers and risk factors measured. Among the 20 blood lipid-related SNPs, LPL rs17411031 was associated with a lower risk of CHD (OR 0.91; 0.84-0.97), an increase in Apolipoprotein AI and HDL-cholesterol, and reduced triglycerides. SORT1 rs599839 was associated with CHD risk (OR 1.20; 1.15-1.26) as well as total- and LDL-cholesterol, and apolipoprotein B. ANGPTL3 rs12042319 was associated with CHD risk (OR 1.11; 1.03, 1.19), total- and LDL-cholesterol, triglycerides, and interleukin-6. CONCLUSION: Several SNPs predicting CHD events appear to involve pathways not currently indexed by the established or emerging risk factors; others involved changes in blood lipids including triglycerides or HDL-cholesterol as well as LDL-cholesterol. The overlapping association of SNPs with multiple risk factors and biomarkers supports the existence of shared points of regulation for these phenotypes.

Leptin levels and depressive symptoms in people with type 2 diabetes: the edinburgh type 2 diabetes study.

OBJECTIVE: Depression in Type 2 diabetes is associated with obesity, cardiovascular disease, and mortality. Leptin is a plausible mediating factor because it has been related to obesity, depression, and cardiovascular disease in nondiabetic populations. We sought to assess whether leptin is related to depressive symptoms in people with Type 2 diabetes. METHODS: One thousand fifty-seven subjects (48.5% women, mean [standard deviation] age = 67.9 [4.2] years) with Type 2 diabetes were assessed for depressive symptoms using the Hospital Anxiety and Depression Scale and other clinical variables by interview and physical examination. Plasma leptin was determined by radioimmunoassay. Multiple linear regression was performed to assess the relationship between depressive symptoms and ln leptin while adjusting for other covariates. A mediation analysis was performed to test whether depressive symptoms mediated the relationship between obesity and leptin. RESULTS: In univariate analyses, symptoms of depression were related to leptin in men (r = 0.214, p < .001) and women (r = 0.146, p = .007). When adjusting for other covariates including body mass index, ischemic heart disease, glycated hemoglobin, duration of diabetes, and treatment with antidepressants, insulin, or glucocorticoids, using a hierarchical multiple linear regression, depressive symptoms (ln Hospital Anxiety and Depression Scale-depression score) were significant only in men (B = 0.083, standard error = 0.037, p = .03). In the mediation analysis, depressive symptoms partially mediated the effect of obesity (body mass index) on leptin in men but not in women. CONCLUSIONS: There is a sex difference in the relationship between depressive symptoms and leptin in people with Type 2 diabetes, with a positive association in men but not in women. Adipocyte-derived factors are associated with depressive symptoms in Type 2 diabetes.

Lipid-related markers and cardiovascular disease prediction.

CONTEXT: The value of assessing various emerging lipid-related markers for prediction of first cardiovascular events is debated. OBJECTIVE: To determine whether adding information on apolipoprotein B and apolipoprotein A-I, lipoprotein(a), or lipoprotein-associated phospholipase A2 to total cholesterol and high-density lipoprotein cholesterol (HDL-C) improves cardiovascular disease (CVD) risk prediction. DESIGN, SETTING, AND PARTICIPANTS: Individual records were available for 165,544 participants without baseline CVD in 37 prospective cohorts (calendar years of recruitment: 1968-2007) with up to 15,126 incident fatal or nonfatal CVD outcomes (10,132 CHD and 4994 stroke outcomes) during a median follow-up of 10.4 years (interquartile range, 7.6-14 years). MAIN OUTCOME MEASURES: Discrimination of CVD outcomes and reclassification of participants across predicted 10-year risk categories of low (<10%), intermediate (10%-<20%), and high (≥20%) risk. RESULTS: The addition of information on various lipid-related markers to total cholesterol, HDL-C, and other conventional risk factors yielded improvement in the model's discrimination: C-index change, 0.0006 (95% CI, 0.0002-0.0009) for the combination of apolipoprotein B and A-I; 0.0016 (95% CI, 0.0009-0.0023) for lipoprotein(a); and 0.0018 (95% CI, 0.0010-0.0026) for lipoprotein-associated phospholipase A2 mass. Net reclassification improvements were less than 1% with the addition of each of these markers to risk scores containing conventional risk factors. We estimated that for 100,000 adults aged 40 years or older, 15,436 would be initially classified at intermediate risk using conventional risk factors alone. Additional testing with a combination of apolipoprotein B and A-I would reclassify 1.1%; lipoprotein(a), 4.1%; and lipoprotein-associated phospholipase A2 mass, 2.7% of people to a 20% or higher predicted CVD risk category and, therefore, in need of statin treatment under Adult Treatment Panel III guidelines. CONCLUSION: In a study of individuals without known CVD, the addition of information on the combination of apolipoprotein B and A-I, lipoprotein(a), or lipoprotein-associated phospholipase A2 mass to risk scores containing total cholesterol and HDL-C led to slight improvement in CVD prediction.

Understanding Study Drug Discontinuation Through EUCLID.

Introduction: Disparities in the care and outcomes of peripheral artery disease (PAD) have been well-established. In part this is due to disparities in enrollment of PAD trial cohorts. However, less attention has been paid to non-random protocol non-adherence after enrollment, which may lead to inaccurate estimates of treatment effects and reduce generalizability of study results. We aimed to ascertain characteristics associated with premature study drug discontinuation in a PAD cohort. Methods: Using data from EUCLID (Examining Use of Ticagrelor in Peripheral Artery Disease), factors associated with study drug discontinuation were assessed using univariable and multivariable Cox proportional hazards models with time to study drug discontinuation as the outcome of interest. Relationships between study drug discontinuation and major adverse cardiovascular events (MACE; cardiovascular death, myocardial infarction, ischemic stroke), major adverse limb events (MALE; acute limb ischemia, major amputation, and lower extremity revascularization), and all-cause hospitalization were assessed. Results: Of 13,842 eligible EUCLID participants, 3,886 (28.1%) prematurely and permanently discontinued study drug over a maximum follow-up of 42 months (annualized rate of 13.2 discontinuations per 100 patient-years). In a multivariable model, premature study drug discontinuation was associated with older age (aHR 1.16, 95%CI 1.14-1.19), eligibility based on prior lower extremity revascularization rather than ABI/TBI criteria (aHR 1.14, 95%CI 1.06-1.23), CLI status (aHR 1.23, 95%CI 1.06-1.42), COPD (aHR 1.36, 95%CI 1.24-1.49), and geographic region. In a multivariable analysis, study drug discontinuation was significantly associated with MACE (aHR 3.27, 95%CI 2.90-3.67, p < 0.001), MALE (aHR 1.84, 95%CI 1.63-2.07, p < 0.001), and all-cause hospitalization (aHR 2.37, 95%CI 2.21-2.54) following study drug discontinuation. Conclusions: This analysis of EUCLID demonstrates that premature, permanent discontinuation of study drug is relatively common in more than a quarter of PAD patients, is unevenly distributed based on geography and other baseline characteristics, and is associated with worse outcomes in a clinical trial context. Study teams leading future PAD trials may want to address the possibility of study drug discontinuation prospectively, as a proactive approach may help investigators to maintain study cohort diversity and representativeness without sacrificing power and precision.