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.

Total Cardiovascular and Limb Events and the Impact of Polyvascular Disease in Chronic Symptomatic Peripheral Artery Disease

Background

Peripheral artery disease (PAD) is associated with heightened risk for major adverse cardiovascular and limb events, but data on the burden of risk for total (first and potentially subsequent) events, and the association with polyvascular disease, are limited. This post hoc analysis of the EUCLID (Examining Use of Ticagrelor in Peripheral Artery Disease) trial evaluated total cardiovascular and limb events among patients with symptomatic PAD, overall and by number of symptomatic vascular territories.

Methods and Results

In the EUCLID trial, patients with symptomatic PAD (lower extremity revascularization >30 days before randomization or ankle‐brachial index ≤0.80) were randomized to treatment with ticagrelor or clopidogrel. Relative effects on total events (cardiovascular death; nonfatal myocardial infarction and ischemic stroke; acute limb ischemia, unstable angina, and transient ischemic attack requiring hospitalization; coronary, carotid, and peripheral revascularization procedures; and amputation for symptomatic PAD) were summarized by hazard ratios (HRs), whereas absolute risks were estimated by incidence rates and mean cumulative functions. Among 13 885 randomized patients, 7600 total cardiovascular and limb events occurred during a median 2.7 years of follow‐up, translating to 60.0 and 62.5 events per 100 patients through 3 years for the ticagrelor and clopidogrel groups, respectively (HR, 0.96; 95% CI, 0.89–1.03; P=0.27). Among 1393 patients with disease in 3 vascular territories, event accrual rates through 3 years for the ticagrelor and clopidogrel groups were 87.3 and 97.7 events per 100 patients, respectively. Absolute risk reductions for ticagrelor relative to clopidogrel at 3 years were −0.2, 6.7, and 10.3 events per 100 patients for 1, 2, and 3 affected vascular territories, respectively (P_interaction=0.09).

Conclusions

Patients with symptomatic PAD have nearly double the number of total events than first events, with rates reflecting the number of affected vascular territories. These findings highlight the clinical relevance of quantifying disease burden in terms of total events and the need for long‐term preventive treatments in high‐risk patient populations.

Registration

URL: https://clinicaltrials.gov/; Unique identifier: NCT01732822.

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).

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).

Ankle-Brachial Index for Risk Stratification in Patients With Symptomatic Peripheral Artery Disease With and Without Prior Lower Extremity Revascularization: Observations From the EUCLID Trial

[Figure: see text].

Association of Heart Failure With Outcomes Among Patients With Peripheral Artery Disease: Insights From EUCLID

Background Peripheral artery disease (PAD) and heart failure (HF) are each independently associated with poor outcomes. Risk factors associated with new-onset HF in patients with primary PAD are unknown. Furthermore, how the presence of HF is associated with outcomes in patients with PAD is unknown. Methods and Results This analysis examined risk relationships of HF on outcomes in patients with symptomatic PAD randomized to ticagrelor or clopidogrel as part of the EUCLID (Examining Use of Ticagrelor in Peripheral Arterial Disease) trial. Patients were stratified based on presence of HF at enrollment. Cox models were used to determine the association of HF with outcomes. A separate Cox model was used to identify risk factors associated with development of HF during follow-up. Patients with PAD and HF had over twice the rate of concomitant coronary artery disease as those without HF. Patients with PAD and HF had significantly increased risk of major adverse cardiovascular events (hazard ratio [HR], 1.31; 95% CI, 1.13-1.51) and all-cause mortality (HR, 1.39; 95% CI, 1.19-1.63). In patients with PAD, the presence of HF was associated with significantly less bleeding (HR, 0.65; 95% CI, 0.45-0.96). Characteristics associated with HF development included age ≥66 (HR, 1.29; 95% CI, 1.18-1.40 per 5 years), diabetes mellitus (HR, 1.85; 95% CI, 1.41-2.43), and weight (bidirectionally associated, ≥76 kg, HR, 0.77; 95% CI, 0.64-0.93; <76 kg, HR, 1.12; 95% CI, 1.07-1.16). Conclusions Patients with PAD and HF have a high rate of coronary artery disease with a high risk for major adverse cardiovascular events and death. These data support the possible need for aggressive treatment of (recurrent) atherosclerotic disease in PAD, especially patients with HF.

Association of Chronic Obstructive Pulmonary Disease with Morbidity and Mortality in Patients with Peripheral Artery Disease: Insights from the EUCLID Trial

Background

Patients with chronic obstructive pulmonary disease (COPD) are at increased risk of developing lower extremity peripheral artery disease (PAD) and suffering PAD-related morbidity and mortality. However, the effect and burden of COPD on patients with PAD is less well defined. This post hoc analysis from EUCLID aimed to analyze the risk of major adverse cardiovascular events (MACE) and major adverse limb events (MALE) in patients with PAD and concomitant COPD compared with those without COPD, and to describe the adverse events specific to patients with COPD.

Methods

EUCLID randomized 13,885 patients with symptomatic PAD to monotherapy with either ticagrelor or clopidogrel for the prevention of MACE. In this analysis, MACE, MALE, mortality, and adverse events were compared between groups with and without COPD using unadjusted and adjusted Cox proportional hazards model.

Results

Of the 13,883 patients with COPD status available at baseline, 11% (n=1538) had COPD. Patients with COPD had a higher risk of MACE (6.02 vs 4.29 events/100 patient-years; p<0.001) due to a significantly higher risk of myocardial infarction (MI) (3.55 vs 1.85 events/100 patient-years; p<0.001) when compared with patients without COPD. These risks persisted after adjustment (MACE: adjusted hazard ratio (aHR) 1.30, 95% confidence interval [CI] 1.11–1.52; p<0.001; MI: aHR 1.45, 95% CI 1.18–1.77; p<0.001). However, patients with COPD did not have an increased risk of MALE or major bleeding. Patients with COPD were more frequently hospitalized for dyspnea and pneumonia (2.66 vs 0.9 events/100 patient-years; aHR 2.77, 95% CI 2.12–3.63; p<0.001) and more frequently discontinued study drug prematurely (19.36 vs 12.54 events/100 patient-years; p<0.001; aHR 1.34, 95% CI 1.22–1.47; p<0.001).

Conclusion

In patients with comorbid PAD and COPD, the risks of MACE, respiratory-related adverse events, and premature study drug discontinuation were higher when compared with patients without COPD.

Registration

ClinicalTrials.gov: NCT01732822.

Cause of Death Among Patients With Peripheral Artery Disease

Background:

Peripheral artery disease is common and associated with high mortality. There are limited data detailing causes of death among patients with peripheral artery disease.

Methods:

EUCLID (Examining Use of Ticagrelor in Peripheral Artery Disease) was a randomized clinical trial that assigned patients with peripheral artery disease to clopidogrel or ticagrelor. We describe the causes of death in EUCLID using mortality end points adjudicated through a clinical events classification process. The association between baseline factors and cardiovascular death was evaluated by Cox proportional hazards modeling. The competing risk of noncardiovascular death was assessed by the cumulative incidence function for cardiovascular death and the Fine and Gray method to ascertain the association between baseline characteristics and cardiovascular mortality.

Results:

A total of 1263 out of 13 885 (9.1%) patients died (median follow-up: 30 months). There were 706 patients (55.9%) with a cardiovascular cause of death and 522 (41.3%) with a noncardiovascular cause of death. The most common cause of cardiovascular death was sudden cardiac death (20.1%); while myocardial infarction (5.2%) and ischemic stroke (3.2%) were uncommon. The most common causes of noncardiovascular death were malignancies (17.9%) and infections (11.9%). The factor most associated with a higher risk of cardiovascular death was age per 5 year increase (HR, 1.26 [95% CI, 1.20–1.32]). Female sex was associated with a lower risk of cardiovascular death (HR, 0.68 [95% CI, 0.56–0.82]). To evaluate the effect of noncardiovascular death as a competing risk, we superimposed the cumulative incidence function curve with the Kaplan-Meier curve. These curves closely approximated each other. After accounting for the competing risk of noncardiovascular death, the magnitude and direction of the factors associated with cardiovascular death were minimally changed.

Conclusions:

Among patients with symptomatic peripheral artery disease, noncardiovascular causes of death reflected a high proportion (40%) of deaths. Accounting for noncardiovascular deaths as a competing risk, there was not a significant change in the risk estimation for cardiovascular death.

Registration:

URL: https://www.clinicaltrials.gov ; Unique identifier: NCT01732822.

Sex-Specific Risks of Major Cardiovascular and Limb Events in Patients With Symptomatic Peripheral Artery Disease

BACKGROUND

Patients with peripheral artery disease (PAD) have a higher risk of major adverse cardiovascular events (MACE) compared with those without PAD.

OBJECTIVES

The aim of this post hoc analysis was to evaluate sex-specific differences in MACE and limb events in the EUCLID (Examining Use of Ticagrelor in PAD) trial.

METHODS

Cox proportional hazards models were used to compare time-to-event outcomes stratified by sex. Covariates were introduced after adjusted model selection.

RESULTS

EUCLID enrolled 13,885 patients with PAD (28% women [n = 3,888]). PAD severity and medical treatment were comparable between sexes, whereas prior lower extremity revascularization was reported less frequently in women (54.8% vs. 57.3%; p = 0.006). Women were older (mean ± SD age: 67.8 ± 8.9 vs. 66.1 ± 8.2 years; p < 0.001) and more likely to have diabetes mellitus (p = 0.004), hypertension, hyperlipidemia, and chronic kidney disease (all p < 0.001). Over a mean follow-up of 30 months, women had a lower risk of MACE (9.5% vs. 11.2%; adjusted hazard ratio: 0.77; 95% confidence interval: 0.68 to 0.88; p < 0.001) and all-cause-mortality (7.6% vs. 9.7%; adjusted hazard ratio: 0.61; 95% confidence interval: 0.53 to 0.71; p < 0.001). In contrast, risk for major adverse limb events (2.6% vs. 3.0%) and hospitalization for acute limb ischemia (1.6% vs. 1.7%) were not different by sex.

CONCLUSIONS

Although women with PAD are at lower risk for MACE and all-cause mortality, risk for limb events was similar between sexes over a mean follow-up of 30 months. Understanding sex-specific differences and dissociation between baseline cardiovascular risk and subsequent cardiovascular events requires further investigation. (A Study Comparing Cardiovascular Effects of Ticagrelor and Clopidogrel in Patients With Peripheral Artery Disease [EUCLID]; NCT01732822).

Association of Hypertension and Arterial Blood Pressure on Limb and Cardiovascular Outcomes in Symptomatic Peripheral Artery Disease: The EUCLID Trial

BACKGROUND

Current guidelines recommend aggressive management of hypertension. Recent evidence suggested potential harm with low blood pressure targets in patients with peripheral artery disease. We investigated the association of a history of hypertension and office systolic blood pressure (SBP) with major adverse cardiovascular events (MACEs) and major adverse limb events (MALEs).

METHODS AND RESULTS

The EUCLID trial (Examining the Use of Ticagrelor in Peripheral Artery Disease) included 13 885 participants with symptomatic peripheral artery disease; median follow-up was 30 months. Cox proportional hazards regression was used to calculate hazard ratios (HRs) for any MACE, MALE, and MALE including lower extremity revascularization. A clinical history of arterial hypertension was present in 10 857 (78%) participants, and these participants were older and more likely to be female when compared with the 3026 (22%) patients without hypertension. In patients with a history of hypertension, the adjusted hazard ratio for MACE was 0.94, 95% CI, 0.82-1.08; P=0.39, and the adjusted hazard ratio for MALE was 1.08, 95% CI, 0.96-1.23; P=0.21. During follow-up, average SBP was 135 mm Hg (125-145). Every 10 mmHg increase in SBP>125 mmHg was associated with an increased risk of MACE (HR, 1.10 [95% CI, 1.06-1.14]; P<0.001), a marginally increased risk of MALE (HR, 1.07 [95% CI, 1.00-1.15]; P=0.062), and an increased risk of MALE/lower extremity revascularization (HR, 1.08 [95% CI, 1.04-1.11]; P<0.001). Every decrease in 10 mmHg SBP ≤125 mmHg was associated with an increased risk of MACE (HR, 1.19 [95% CI, 1.09-1.31]; P<0.001) but not MALE or MALE/lower extremity revascularization (HR, 1.02 [95% CI, 0.84-1.23], P=0.824; HR, 1.04 [95% CI, 0.95-1.13], P=0.392, respectively).

CONCLUSIONS

History of hypertension was not associated with higher hazard for MACE or MALE in patients with peripheral artery disease. In contrast, there was a higher hazard of MACE in patients with out-of-target low and high SBP. High but not low SBP was associated with an increased risk of ischemic limb events. Registration: URL: https://www.clinicaltrials.gov; Unique identifier: NCT01732822.

Incidence and Factors Associated With Major Amputation in Patients With Peripheral Artery Disease

Background:

Peripheral artery disease (PAD) is associated with increased risk of mortality, cardiovascular morbidity, and major amputation. Data on major amputation from a large randomized trial that included a substantial cohort of patients without critical limb ischemia (CLI) have not been described. The objective was to describe the incidence and types of amputations in the EUCLID trial (Examining Use of Ticagrelor in Peripheral Artery Disease) population, subcategorize amputations in the CLI versus no CLI cohorts, and describe the events surrounding major amputation.

Methods and Results:

Postrandomization major amputation was analyzed in the EUCLID trial. Patients were stratified by baseline CLI status. The occurrence of major amputation was ascertained and defined as the highest level. Perioperative events surrounding major amputation were obtained including acute limb ischemia, revascularization, and all-cause mortality. All variables were assessed for significance in univariable and multivariable models. The rate of major amputation during the course of the trial was 1.6% overall, 8.4% in the CLI at baseline group, and 1.2% in the no CLI at baseline group. The annualized rate of major amputation was 0.6% in PAD overall, 3.9% in the CLI at baseline group, and 0.5% in the no CLI at baseline group. Several factors were associated with increased risk of major amputation, including history of amputation, the presence of diabetes mellitus, baseline Rutherford category 4 to 6, and an ankle-brachial index <0.8. Factors associated with a lower risk for major amputation included prior statin use. The 30-day mortality rate after major amputation was 6.5% overall, 5.6% in the CLI at baseline group, and 6.8% in the no CLI at baseline group. The annual mortality rate following major amputation was 22.8% in the CLI at baseline group and 16.0% in the no CLI at baseline group.

Conclusions:

The risk factors for major amputation in EUCLID patients are similar to previous large registries’ reports except for diabetes mellitus in patients with CLI. The mortality following major amputation is lower in the EUCLID trial compared with registry data.

Registration:

URL: https://www.clinicaltrials.gov ; Unique identifier: NCT01732822.

Incidence, Characteristics, and Outcomes of Myocardial Infarction in Patients With Peripheral Artery Disease: Insights From the EUCLID Trial

Importance

Patients with peripheral artery disease (PAD) are at high risk for myocardial infarction (MI).

Objective

To characterize the incidence and types of MI in a PAD population, identify factors associated with MI, and determine the association of MI with cardiovascular mortality and acute limb ischemia.

Design, Setting, and Participants

The Study Comparing Cardiovascular Effects of Ticagrelor and Clopidogrel in Patients With Peripheral Artery Disease (EUCLID) was a double-blind randomized clinical trial conducted at 811 sites in 28 countries that randomized 13 885 patients with symptomatic PAD to monotherapy with ticagrelor or clopidogrel. Participants had an ankle-brachial index (ABI) of 0.80 or less or previous lower extremity revascularization. Median follow-up was 30 months. For these analyses, patients were evaluated for MI occurrence during follow-up irrespective of treatment. Data were analyzed from June 2017 to September 2018.

Main Outcomes and Measures

An adjudication clinical events committee classified MI as type 1 (spontaneous), type 2 (secondary), type 3 (sudden cardiac death), type 4a (less than 48 hours after percutaneous coronary intervention), type 4b (definite stent thrombosis), or type 5 (less than 72 hours after coronary artery bypass graft). A multivariate regression model was developed by stepwise selection to identify factors associated with MI, and a time-dependent multivariate Cox regression analysis was performed to determine the association of MI with cardiovascular death and acute limb ischemia requiring hospitalization.

Results

Of the 13 885 patients included in this analysis, 9997 (72.0%) were male, and the median (interquartile range) age was 66 (60-73) years. Myocardial infarction occurred in 683 patients (4.9%; 2.4 events per 100 patient-years) during a median follow-up of 30 months. Patients experiencing MI were older (median [interquartile range] age, 69 [62-75] vs 66 [60-72] years), more likely to have diabetes (349 of 683 [51.1%] vs 4996 of 13 202 [37.8%]) or a previous lower extremity revascularization (466 of 683 [68.2%] vs 7409 of 13 202 [56.1%]), and had a lower ABI (if included by ABI) compared with censored patients. Of the 683 patients with MI during follow-up, the most common MI type was type 1 (405 [59.3%]), followed by type 2 (236 [34.6%]), type 4a (14 [2.0%]), type 3 (12 [1.8%]), type 4b (11 [1.6%]), and type 5 (5 [0.7%]). Postrandomization MI was independently associated with cardiovascular death (adjusted hazard ratio, 9.0; 95% CI, 7.3-11.2; P < .001) and acute limb ischemia requiring hospitalization (adjusted hazard ratio, 2.5; 95% CI, 1.3-5.0; P = .008).

Conclusions and Relevance

Approximately 5% of patients with symptomatic PAD had an MI during a median follow-up of 30 months. Type 1 MI (spontaneous) was the most common MI type; however, one-third of MIs were type 2 MI (secondary). More research is needed to identify therapies to reduce the risk of MI in patients with PAD and to improve management of type 2 MI.

Trial Registration

ClinicalTrials.gov Identifier: NCT01732822.

P935Effect of hypertension and systolic blood pressure on cardiovascular and limb outcomes in patients with symptomatic peripheral artery disease: the EUCLID trial

Background

Hypertension is a risk factor for major adverse cardiac events (MACE) in patients with symptomatic peripheral artery disease (PAD).

Purpose

The effects of a history of hypertension and baseline systolic blood pressure (SBP) on MACE and major adverse limb events (MALE), including acute limb ischemia and major amputation, were evaluated in the Examining Use of tiCagreLor In paD (EUCLID) trial.

Methods

EUCLID randomized 13,885 patients with PAD and found no benefit of ticagrelor compared with clopidogrel on risk of MACE or MALE. The median duration of follow up was approximately 30 months. This post hoc, subgroup analysis evaluated the effects of hypertension history at baseline on the hazard for MACE and MALE. An adjusted restricted cubic spline regression analysis evaluated the association of SBP with MACE and MALE.

Results

A clinical history of hypertension was present in 10,857 (78%) patients at baseline and these patients were more likely to be older, female, white or African American, and reside in North America compared with the 3026 without hypertension. Hypertension was associated with a higher prevalence of concomitant cardiovascular diseases, polyvascular disease, diabetes, and prior coronary interventions. MACE occurred at a rate of 4.63 events/100 pt-yrs in participants with hypertension and 3.64 events/100 pt-yrs in participants without hypertension, (adjusted hazard ratio [aHR] 0.94, 95% CI 0.82–1.08; p=0.38). MALE occurred at a rate of 1.11 events/100 pt-yrs in those with hypertension and 1.38 events/100 pt-yrs in those without hypertension (p=0.054) (aHR 0.93 (95% CI 0.73, 1.18) p=0.55. The adjusted spline model for MACE and SBP demonstrated a significantly non-linear relationship with a HR 1.08 (95% CI 1.01, 1.15), p=0.0275 for every 10-unit decrease <135 mmHg SBP and HR 1.11 (1.06, 1.16), p<0.0001 for every 10-unit increase >135 mmHg (figure). There was no association between baseline SBP and MALE events.

Conclusions

A history of hypertension was not associated with a higher adjusted hazard for MACE or MALE in participants with PAD. In contrast, SBP at baseline was associated with increased risk of MACE at values both above and below 135 mmHg.

Acknowledgement/Funding

EUCLID was sponsored by AstraZeneca

Cardiovascular and Limb Outcomes in Patients With Diabetes and Peripheral Artery Disease: The EUCLID Trial

BACKGROUND

Diabetes confers an increased risk for atherosclerotic cardiovascular disease, but less is known about the independent risk diabetes confers on major cardiovascular and limb events in patients with symptomatic peripheral artery disease (PAD) on contemporary management.

OBJECTIVES

The authors sought to assess the risk of cardiovascular and limb events in patients with PAD and diabetes as compared with those with PAD alone.

METHODS

In the EUCLID (Examining Use of Ticagrelor in Peripheral Artery Disease) trial, 13,885 patients with symptomatic PAD were evaluated with a primary endpoint of an adjudicated composite of major adverse cardiovascular events (MACE) (cardiovascular death, myocardial infarction, ischemic stroke) followed over a median of ∼30 months. The diabetes subgroup was analyzed compared with the subgroup without diabetes, and further examined for diabetes-specific factors such as glycosylated hemoglobin (HbA_1c) that might affect risk for major cardiovascular and limb outcomes.

RESULTS

A total of 5,345 patients (38.5%) had diabetes; the majority (n = 5,134 [96.1%]) had type 2 diabetes. The primary endpoint occurred in 15.9% of patients with PAD and diabetes as compared with 10.4% of those without diabetes (absolute risk difference 5.5%; adjusted hazard ratio: 1.56; 95% confidence interval [CI]: 1.41 to 1.72; p < 0.001). Every 1% increase in HbA_1c was associated with a 14.2% increased relative risk for MACE (95% CI: 1.09 to 1.20; p < 0.0001).

CONCLUSIONS

Patients with PAD and diabetes are at high risk for cardiovascular and limb ischemic events, even on contemporary therapies. Every 1% increase in HbA_1c was associated with a 14.2% increased relative risk for MACE (95% CI: 1.09 to 1.20; p < 0.0001). (A Study Comparing Cardiovascular Effects of Ticagrelor and Clopidogrel in Patients With Peripheral Artery Disease [EUCLID]; NCT01732822).

Cardiovascular Outcomes After Lower Extremity Endovascular or Surgical Revascularization: The EUCLID Trial

BACKGROUND

Lower extremity revascularization (LER) is a common treatment in patients with peripheral artery disease (PAD), but long-term outcomes are poorly defined.

OBJECTIVES

The aim was to analyze LER in the EUCLID (Examining Use of tiCagreLor In paD) trial to determine predictors and cardiovascular outcomes.

METHODS

Patients were grouped according to whether they received a post-randomization LER (n = 1,738) or not (n = 12,147). All variables were assessed for significance in univariable and parsimonious multivariable models. The primary endpoint was myocardial infarction, ischemic stroke, or cardiovascular death; major adverse limb events (MALE) included acute limb ischemia or major amputation.

RESULTS

A post-randomization LER occurred in 12.5% of patients and was an endovascular LER in 74.7%. Endovascular LERs were performed more often in North America, whereas surgical procedures occurred more frequently in Europe. Independent factors predicting LER were prior and type of prior LER, geographic region, limb symptoms, diabetes, and smoking. A post-randomization LER was associated with an increased risk for the primary endpoint (hazard ratio: 1.60; 95% confidence interval: 1.35 to 1.90; p < 0.0001) and MALE (hazard ratio: 12.0; 95% confidence interval: 9.47 to 15.30; p < 0.0001). Event rates for the primary endpoint after LER were numerically higher in the surgical subgroup, but MALE were similar between surgical and endovascular LER.

CONCLUSIONS

In the EUCLID trial, LER was most often endovascular. Following LER, there was an increased hazard for the primary endpoint (with higher event rates in the surgical group) and a markedly increased risk for MALE events (with similar event rates between surgical and endovascular LER procedures). (A Study Comparing Cardiovascular Effects of Ticagrelor and Clopidogrel in Patients With Peripheral Artery Disease [EUCLID]; 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

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.

Polyvascular Disease and Risk of Major Adverse Cardiovascular Events in Peripheral Artery Disease: A Secondary Analysis of the EUCLID Trial

IMPORTANCE

The effect of polyvascular disease on cardiovascular outcomes in the background of peripheral artery disease (PAD) is unclear.

OBJECTIVE

To determine the risk of ischemic events (both cardiac and limb) among patients with PAD and polyvascular disease.

DESIGN, SETTING, AND PARTICIPANTS

In this post hoc secondary analysis of the international Examining Use of Ticagrelor in Peripheral Artery Disease (EUCLID) trial, outcomes were compared among 13 885 enrolled patients with PAD alone, PAD + coronary artery disease (CAD), PAD + cerebrovascular disease (CVD), and PAD + CAD + CVD. Adjusted Cox proportional hazards regression models were implemented to determine the risk associated with polyvascular disease and outcomes, and intention-to-treat analysis was performed. The EUCLID trial was conducted from December 31, 2012, to March 7, 2014; the present post hoc analysis was performed from June 1, 2017, to February 5, 2018.

INTERVENTIONS

EUCLID evaluated ticagrelor vs clopidogrel in preventing major adverse cardiac events (cardiovascular death, myocardial infarction [MI], or ischemic stroke) and major bleeding in patients with PAD.

MAIN OUTCOMES AND MEASURES

The primary end point was a composite of cardiovascular death, MI, or ischemic stroke. Key secondary end points included the individual components of the primary end point and acute limb ischemia leading to hospitalization, major amputation, and lower-extremity revascularization. The primary end point of Thrombolysis in Myocardial Infarction (TIMI) major bleeding was also evaluated.

RESULTS

The EUCLID trial randomized 13 885 patients with a median age of 66 years (interquartile range, 60-73 years), of whom 3888 (28.0%) were women. At baseline, 7804 patients (56.2%) had PAD alone; 2639 (19.0%) had PAD + CAD; 2049 (14.8%) had PAD + CVD; and 1393 (10.0%) had PAD + CAD + CVD. Compared with patients with isolated PAD, the adjusted hazard ratios (aHRs) for major adverse cardiac events were 1.34 (95% CI, 1.15-1.57; P < .001) for PAD + CVD, 1.65 (95% CI, 1.43-1.91; P < .001) for PAD + CAD, and 1.99 (95% CI, 1.69-2.34; P < .001) for PAD + CAD + CVD. The aHRs for lower-extremity revascularization were 1.17 (95% CI, 1.03-1.34; P = .01) for PAD + CAD, 1.17 (95% CI, 1.02-1.35; P = .02) for PAD + CVD, and 1.34 (95% CI, 1.15-1.57; P < .001) for PAD + CAD + CVD. Polyvascular disease was not associated with an increased risk of acute limb ischemia (aHR for PAD + CVD, 0.91; 95% CI, 0.62-1.34, P = .63; PAD + CAD, 0.93; 95% CI, 0.64-1.34, P = .69; and PAD + CAD + CVD, 0.98; 95% CI, 0.63-1.53, P = .93), major amputation (aHR for PAD + CVD, 0.83; 95% CI, 0.54-1.27, P = .40; PAD + CAD, 0.74; 95% CI, 0.47-1.16, P = .19; and PAD + CAD + CVD, 1.12; 95% CI, 0.69-1.80, P = .65), or TIMI major bleeding (PAD + CVD, 0.98; 0.66-1.44, P = .91; PAD + CAD, 1.04; 0.74-1.48, P = .81; and PAD + CAD + CVD, 0.96; 95% CI, 0.62-1.51, P = .88).

CONCLUSIONS AND RELEVANCE

Compared with patients with PAD alone, the risk of major adverse cardiac events and lower-extremity revascularization increased with multiple vascular bed involvement. There was no clear increased risk of bleeding associated with polyvascular disease.

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.

Smoking, Haemostatic Factors and the Severity of Aorto-lliac and Femoro-Popliteal Disease

To determine relationships between haemostatic and rheological factors and severity of peripheral atherosclerosis and differences by site, an angiographic cross-sectional survey was carried out on 192 men and women with intermittent claudication or rest pain. 34 patients were classified as having aorto-iliac disease, 85 femoro-popliteal disease and 73 dual-site disease. Mean levels of haemostatic or rheological factors did not differ significantly between the three site groups. In all 192 patients, disease severity in the femoro-popliteal segments was correlated with plasma nephelometric fibrinogen (r = 0.20, p ≤0.01), von Willebrand factor (r = 0.14, p ≤0.05) and fibrin D-dimer (r = 0.22, p ≤0.001). On multiple regression analyses, fibrinogen was independently associated with disease severity in the femoro-popliteal segments (p ≤0.05), but not in the aorto-iliac segments. Adjustment for packyears or serum thiocyanate had little effect on the association of fibrinogen with severity of disease. An inverse relationship between plasminogen activator inhibitor and disease severity in the femoro-popliteal segments was found only in men (r = -0.24, p ≤0.01). We conclude that elevated fibrinogen and disturbed fibrinolytic activity may be related to the extent of disease within the femoro-popliteal arteries, more so than in the aorto-iliac arteries.

International Validation of the Thrombolysis in Myocardial Infarction (TIMI) Risk Score for Secondary Prevention in Post-MI Patients: A Collaborative Analysis of the Chronic Kidney Disease Prognosis Consortium and the Risk Validation Scientific Committee

BACKGROUND

The Thrombolysis in Myocardial Infarction (TIMI) Risk Score for Secondary Prevention (TRS2°P), a 0-to-9-point system based on the presence/absence of 9 clinical factors, was developed to classify the risk of major adverse cardiovascular events (MACE) (a composite of cardiovascular death, recurrent myocardial infarction, or ischemic stroke) among patients with a recent myocardial infarction. Its performance has not been examined internationally outside of a clinical trial setting.

METHODS AND RESULTS

We evaluated the performance of TRS2°P for predicting MACE in 53 599 patients with recent myocardial infarction in 5 international cohorts from New Zealand, South Korea, Sweden, and the United States participating in the Chronic Kidney Disease Prognosis Consortium. Overall, there were 19 444 cases of MACE across 5 cohorts over a mean follow-up of 5 years, and the overall MACE rate ranged from 5.0 to 18.4 (per 100 person-years). The TRS2°P showed modest calibration (Brier score ranged from 0.144 to 0.173) and discrimination (C-statistics >0.61 in all studies except 1 from Korea with 0.55) across cohorts relative to its original Brier score of 0.098 and C-statistic of 0.67 in the derived data set. Although there was some heterogeneity across cohorts, the 9 predictors in the TRS2°P were generally associated with higher MACE risk, with strongest associations observed (meta-analyzed adjusted hazard ratio 1.6-1.7) for history of heart failure, age ≥75 years, and prior stroke, followed by peripheral artery disease, kidney dysfunction, diabetes mellitus, and hypertension (hazard ratio 1.3-1.4). Prior coronary bypass graft surgery and smoking did not reach statistical significance (hazard ratio ≈1.1).

CONCLUSIONS

TRS2°P, a simple scoring system with 9 routine clinical factors, was modestly predictive of secondary events when applied in patients with recent myocardial infarction from diverse clinical and geographic settings.

Time trends in peripheral artery disease incidence, prevalence and secondary preventive therapy: a cohort study in The Health Improvement Network in the UK

OBJECTIVES

To assess time trends in symptomatic peripheral artery disease (PAD) incidence and prevalence, and secondary preventive therapy.

DESIGN

Cohort study using The Health Improvement Network.

SETTING

UK primary care.

PARTICIPANTS

Individuals aged 50-89 years identified annually between 2000 and 2014. Participants with symptomatic PAD were identified using Read codes.

OUTCOME MEASURES

Incidence and prevalence of symptomatic PAD from 2000 to 2014, overall and by sex and age. Proportion of patients prescribed secondary preventive therapy with acetylsalicylic acid (ASA), clopidogrel, an ACE inhibitor, an angiotensin receptor blocker (ARB) and/or a statin.

RESULTS

The incidence of symptomatic PAD per 10 000 person-years decreased over time, from 38.6 (men: 51.0; women: 28.7) in 2000 to 17.3 (men: 23.1; women: 12.4) in 2014. The prevalence of symptomatic PAD decreased from 3.4% (men: 4.5%; women: 2.5%) in 2000 to 2.4% (men: 3.1%; women: 1.7%) in 2014. Incidence and prevalence decreases were observed in all age groups. The proportions of patients prescribed ASA monotherapy, clopidogrel monotherapy and dual antiplatelet therapy in the 2 months after PAD diagnosis were 42.7%, 2.9% and 2.5%, respectively, during 2000-2003, and 44.7%, 11.0% and 5.2%, respectively, during 2012-2014. For ACE inhibitor/ARB therapy and statins, proportions in the 2 months after diagnosis were 30.2% and 31.2%, respectively, during 2000-2003, and 45.1% and 65.9%, respectively, during 2012-2014.

CONCLUSION

The incidence and prevalence of symptomatic PAD diagnosed in UK primary care are decreasing. A large proportion of the population with PAD in clinical practice does not receive guideline-recommended secondary prevention therapy.

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 .).

Peripheral artery disease: epidemiology and global perspectives

Global populations are undergoing a major epidemiological transition in which the burden of atherosclerotic cardiovascular diseases is shifting rapidly from high-income to low-income and middle-income countries (LMICs). Peripheral artery disease (PAD) is no exception, so that greater focus is now required on the prevention and management of this disease in less-advantaged countries. In this Review, we examine the epidemiology of PAD and, where feasible, take a global perspective. However, the dearth of publications in LMICs means an unavoidable over-reliance on studies in high-income countries. Research to date suggests that PAD might affect a greater proportion of women than men in LMICs. Although factors such as poverty, industrialization, and infection might conceivably influence the development of PAD in such settings, the ageing of the population and increase in traditional cardiovascular risk factors, such as smoking, diabetes mellitus, and hypertension, are likely to be the main driving forces.

Measuring the health-related Sustainable Development Goals in 188 countries: a baseline analysis from the Global Burden of Disease Study 2015

BACKGROUND

In September, 2015, the UN General Assembly established the Sustainable Development Goals (SDGs). The SDGs specify 17 universal goals, 169 targets, and 230 indicators leading up to 2030. We provide an analysis of 33 health-related SDG indicators based on the Global Burden of Diseases, Injuries, and Risk Factors Study 2015 (GBD 2015).

METHODS

We applied statistical methods to systematically compiled data to estimate the performance of 33 health-related SDG indicators for 188 countries from 1990 to 2015. We rescaled each indicator on a scale from 0 (worst observed value between 1990 and 2015) to 100 (best observed). Indices representing all 33 health-related SDG indicators (health-related SDG index), health-related SDG indicators included in the Millennium Development Goals (MDG index), and health-related indicators not included in the MDGs (non-MDG index) were computed as the geometric mean of the rescaled indicators by SDG target. We used spline regressions to examine the relations between the Socio-demographic Index (SDI, a summary measure based on average income per person, educational attainment, and total fertility rate) and each of the health-related SDG indicators and indices.

FINDINGS

In 2015, the median health-related SDG index was 59·3 (95% uncertainty interval 56·8-61·8) and varied widely by country, ranging from 85·5 (84·2-86·5) in Iceland to 20·4 (15·4-24·9) in Central African Republic. SDI was a good predictor of the health-related SDG index (r2=0·88) and the MDG index (r2=0·92), whereas the non-MDG index had a weaker relation with SDI (r2=0·79). Between 2000 and 2015, the health-related SDG index improved by a median of 7·9 (IQR 5·0-10·4), and gains on the MDG index (a median change of 10·0 [6·7-13·1]) exceeded that of the non-MDG index (a median change of 5·5 [2·1-8·9]). Since 2000, pronounced progress occurred for indicators such as met need with modern contraception, under-5 mortality, and neonatal mortality, as well as the indicator for universal health coverage tracer interventions. Moderate improvements were found for indicators such as HIV and tuberculosis incidence, minimal changes for hepatitis B incidence took place, and childhood overweight considerably worsened.

INTERPRETATION

GBD provides an independent, comparable avenue for monitoring progress towards the health-related SDGs. Our analysis not only highlights the importance of income, education, and fertility as drivers of health improvement but also emphasises that investments in these areas alone will not be sufficient. Although considerable progress on the health-related MDG indicators has been made, these gains will need to be sustained and, in many cases, accelerated to achieve the ambitious SDG targets. The minimal improvement in or worsening of health-related indicators beyond the MDGs highlight the need for additional resources to effectively address the expanded scope of the health-related SDGs.

FUNDING

Bill & Melinda Gates Foundation.

Global, regional, and national comparative risk assessment of 79 behavioural, environmental and occupational, and metabolic risks or clusters of risks, 1990-2015: a systematic analysis for the Global Burden of Disease Study 2015

BACKGROUND

The Global Burden of Diseases, Injuries, and Risk Factors Study 2015 provides an up-to-date synthesis of the evidence for risk factor exposure and the attributable burden of disease. By providing national and subnational assessments spanning the past 25 years, this study can inform debates on the importance of addressing risks in context.

METHODS

We used the comparative risk assessment framework developed for previous iterations of the Global Burden of Disease Study to estimate attributable deaths, disability-adjusted life-years (DALYs), and trends in exposure by age group, sex, year, and geography for 79 behavioural, environmental and occupational, and metabolic risks or clusters of risks from 1990 to 2015. This study included 388 risk-outcome pairs that met World Cancer Research Fund-defined criteria for convincing or probable evidence. We extracted relative risk and exposure estimates from randomised controlled trials, cohorts, pooled cohorts, household surveys, census data, satellite data, and other sources. We used statistical models to pool data, adjust for bias, and incorporate covariates. We developed a metric that allows comparisons of exposure across risk factors-the summary exposure value. Using the counterfactual scenario of theoretical minimum risk level, we estimated the portion of deaths and DALYs that could be attributed to a given risk. We decomposed trends in attributable burden into contributions from population growth, population age structure, risk exposure, and risk-deleted cause-specific DALY rates. We characterised risk exposure in relation to a Socio-demographic Index (SDI).

FINDINGS

Between 1990 and 2015, global exposure to unsafe sanitation, household air pollution, childhood underweight, childhood stunting, and smoking each decreased by more than 25%. Global exposure for several occupational risks, high body-mass index (BMI), and drug use increased by more than 25% over the same period. All risks jointly evaluated in 2015 accounted for 57·8% (95% CI 56·6-58·8) of global deaths and 41·2% (39·8-42·8) of DALYs. In 2015, the ten largest contributors to global DALYs among Level 3 risks were high systolic blood pressure (211·8 million [192·7 million to 231·1 million] global DALYs), smoking (148·6 million [134·2 million to 163·1 million]), high fasting plasma glucose (143·1 million [125·1 million to 163·5 million]), high BMI (120·1 million [83·8 million to 158·4 million]), childhood undernutrition (113·3 million [103·9 million to 123·4 million]), ambient particulate matter (103·1 million [90·8 million to 115·1 million]), high total cholesterol (88·7 million [74·6 million to 105·7 million]), household air pollution (85·6 million [66·7 million to 106·1 million]), alcohol use (85·0 million [77·2 million to 93·0 million]), and diets high in sodium (83·0 million [49·3 million to 127·5 million]). From 1990 to 2015, attributable DALYs declined for micronutrient deficiencies, childhood undernutrition, unsafe sanitation and water, and household air pollution; reductions in risk-deleted DALY rates rather than reductions in exposure drove these declines. Rising exposure contributed to notable increases in attributable DALYs from high BMI, high fasting plasma glucose, occupational carcinogens, and drug use. Environmental risks and childhood undernutrition declined steadily with SDI; low physical activity, high BMI, and high fasting plasma glucose increased with SDI. In 119 countries, metabolic risks, such as high BMI and fasting plasma glucose, contributed the most attributable DALYs in 2015. Regionally, smoking still ranked among the leading five risk factors for attributable DALYs in 109 countries; childhood underweight and unsafe sex remained primary drivers of early death and disability in much of sub-Saharan Africa.

INTERPRETATION

Declines in some key environmental risks have contributed to declines in critical infectious diseases. Some risks appear to be invariant to SDI. Increasing risks, including high BMI, high fasting plasma glucose, drug use, and some occupational exposures, contribute to rising burden from some conditions, but also provide opportunities for intervention. Some highly preventable risks, such as smoking, remain major causes of attributable DALYs, even as exposure is declining. Public policy makers need to pay attention to the risks that are increasingly major contributors to global burden.

FUNDING

Bill & Melinda Gates Foundation.

Global, regional, and national life expectancy, all-cause mortality, and cause-specific mortality for 249 causes of death, 1980-2015: a systematic analysis for the Global Burden of Disease Study 2015

BACKGROUND

Improving survival and extending the longevity of life for all populations requires timely, robust evidence on local mortality levels and trends. The Global Burden of Disease 2015 Study (GBD 2015) provides a comprehensive assessment of all-cause and cause-specific mortality for 249 causes in 195 countries and territories from 1980 to 2015. These results informed an in-depth investigation of observed and expected mortality patterns based on sociodemographic measures.

METHODS

We estimated all-cause mortality by age, sex, geography, and year using an improved analytical approach originally developed for GBD 2013 and GBD 2010. Improvements included refinements to the estimation of child and adult mortality and corresponding uncertainty, parameter selection for under-5 mortality synthesis by spatiotemporal Gaussian process regression, and sibling history data processing. We also expanded the database of vital registration, survey, and census data to 14 294 geography-year datapoints. For GBD 2015, eight causes, including Ebola virus disease, were added to the previous GBD cause list for mortality. We used six modelling approaches to assess cause-specific mortality, with the Cause of Death Ensemble Model (CODEm) generating estimates for most causes. We used a series of novel analyses to systematically quantify the drivers of trends in mortality across geographies. First, we assessed observed and expected levels and trends of cause-specific mortality as they relate to the Socio-demographic Index (SDI), a summary indicator derived from measures of income per capita, educational attainment, and fertility. Second, we examined factors affecting total mortality patterns through a series of counterfactual scenarios, testing the magnitude by which population growth, population age structures, and epidemiological changes contributed to shifts in mortality. Finally, we attributed changes in life expectancy to changes in cause of death. We documented each step of the GBD 2015 estimation processes, as well as data sources, in accordance with Guidelines for Accurate and Transparent Health Estimates Reporting (GATHER).

FINDINGS

Globally, life expectancy from birth increased from 61·7 years (95% uncertainty interval 61·4-61·9) in 1980 to 71·8 years (71·5-72·2) in 2015. Several countries in sub-Saharan Africa had very large gains in life expectancy from 2005 to 2015, rebounding from an era of exceedingly high loss of life due to HIV/AIDS. At the same time, many geographies saw life expectancy stagnate or decline, particularly for men and in countries with rising mortality from war or interpersonal violence. From 2005 to 2015, male life expectancy in Syria dropped by 11·3 years (3·7-17·4), to 62·6 years (56·5-70·2). Total deaths increased by 4·1% (2·6-5·6) from 2005 to 2015, rising to 55·8 million (54·9 million to 56·6 million) in 2015, but age-standardised death rates fell by 17·0% (15·8-18·1) during this time, underscoring changes in population growth and shifts in global age structures. The result was similar for non-communicable diseases (NCDs), with total deaths from these causes increasing by 14·1% (12·6-16·0) to 39·8 million (39·2 million to 40·5 million) in 2015, whereas age-standardised rates decreased by 13·1% (11·9-14·3). Globally, this mortality pattern emerged for several NCDs, including several types of cancer, ischaemic heart disease, cirrhosis, and Alzheimer's disease and other dementias. By contrast, both total deaths and age-standardised death rates due to communicable, maternal, neonatal, and nutritional conditions significantly declined from 2005 to 2015, gains largely attributable to decreases in mortality rates due to HIV/AIDS (42·1%, 39·1-44·6), malaria (43·1%, 34·7-51·8), neonatal preterm birth complications (29·8%, 24·8-34·9), and maternal disorders (29·1%, 19·3-37·1). Progress was slower for several causes, such as lower respiratory infections and nutritional deficiencies, whereas deaths increased for others, including dengue and drug use disorders. Age-standardised death rates due to injuries significantly declined from 2005 to 2015, yet interpersonal violence and war claimed increasingly more lives in some regions, particularly in the Middle East. In 2015, rotaviral enteritis (rotavirus) was the leading cause of under-5 deaths due to diarrhoea (146 000 deaths, 118 000-183 000) and pneumococcal pneumonia was the leading cause of under-5 deaths due to lower respiratory infections (393 000 deaths, 228 000-532 000), although pathogen-specific mortality varied by region. Globally, the effects of population growth, ageing, and changes in age-standardised death rates substantially differed by cause. Our analyses on the expected associations between cause-specific mortality and SDI show the regular shifts in cause of death composition and population age structure with rising SDI. Country patterns of premature mortality (measured as years of life lost [YLLs]) and how they differ from the level expected on the basis of SDI alone revealed distinct but highly heterogeneous patterns by region and country or territory. Ischaemic heart disease, stroke, and diabetes were among the leading causes of YLLs in most regions, but in many cases, intraregional results sharply diverged for ratios of observed and expected YLLs based on SDI. Communicable, maternal, neonatal, and nutritional diseases caused the most YLLs throughout sub-Saharan Africa, with observed YLLs far exceeding expected YLLs for countries in which malaria or HIV/AIDS remained the leading causes of early death.

INTERPRETATION

At the global scale, age-specific mortality has steadily improved over the past 35 years; this pattern of general progress continued in the past decade. Progress has been faster in most countries than expected on the basis of development measured by the SDI. Against this background of progress, some countries have seen falls in life expectancy, and age-standardised death rates for some causes are increasing. Despite progress in reducing age-standardised death rates, population growth and ageing mean that the number of deaths from most non-communicable causes are increasing in most countries, putting increased demands on health systems.

FUNDING

Bill & Melinda Gates Foundation.

Global, regional, and national disability-adjusted life-years (DALYs) for 315 diseases and injuries and healthy life expectancy (HALE), 1990-2015: a systematic analysis for the Global Burden of Disease Study 2015

BACKGROUND

Healthy life expectancy (HALE) and disability-adjusted life-years (DALYs) provide summary measures of health across geographies and time that can inform assessments of epidemiological patterns and health system performance, help to prioritise investments in research and development, and monitor progress toward the Sustainable Development Goals (SDGs). We aimed to provide updated HALE and DALYs for geographies worldwide and evaluate how disease burden changes with development.

METHODS

We used results from the Global Burden of Diseases, Injuries, and Risk Factors Study 2015 (GBD 2015) for all-cause mortality, cause-specific mortality, and non-fatal disease burden to derive HALE and DALYs by sex for 195 countries and territories from 1990 to 2015. We calculated DALYs by summing years of life lost (YLLs) and years of life lived with disability (YLDs) for each geography, age group, sex, and year. We estimated HALE using the Sullivan method, which draws from age-specific death rates and YLDs per capita. We then assessed how observed levels of DALYs and HALE differed from expected trends calculated with the Socio-demographic Index (SDI), a composite indicator constructed from measures of income per capita, average years of schooling, and total fertility rate.

FINDINGS

Total global DALYs remained largely unchanged from 1990 to 2015, with decreases in communicable, neonatal, maternal, and nutritional (Group 1) disease DALYs offset by increased DALYs due to non-communicable diseases (NCDs). Much of this epidemiological transition was caused by changes in population growth and ageing, but it was accelerated by widespread improvements in SDI that also correlated strongly with the increasing importance of NCDs. Both total DALYs and age-standardised DALY rates due to most Group 1 causes significantly decreased by 2015, and although total burden climbed for the majority of NCDs, age-standardised DALY rates due to NCDs declined. Nonetheless, age-standardised DALY rates due to several high-burden NCDs (including osteoarthritis, drug use disorders, depression, diabetes, congenital birth defects, and skin, oral, and sense organ diseases) either increased or remained unchanged, leading to increases in their relative ranking in many geographies. From 2005 to 2015, HALE at birth increased by an average of 2·9 years (95% uncertainty interval 2·9-3·0) for men and 3·5 years (3·4-3·7) for women, while HALE at age 65 years improved by 0·85 years (0·78-0·92) and 1·2 years (1·1-1·3), respectively. Rising SDI was associated with consistently higher HALE and a somewhat smaller proportion of life spent with functional health loss; however, rising SDI was related to increases in total disability. Many countries and territories in central America and eastern sub-Saharan Africa had increasingly lower rates of disease burden than expected given their SDI. At the same time, a subset of geographies recorded a growing gap between observed and expected levels of DALYs, a trend driven mainly by rising burden due to war, interpersonal violence, and various NCDs.

INTERPRETATION

Health is improving globally, but this means more populations are spending more time with functional health loss, an absolute expansion of morbidity. The proportion of life spent in ill health decreases somewhat with increasing SDI, a relative compression of morbidity, which supports continued efforts to elevate personal income, improve education, and limit fertility. Our analysis of DALYs and HALE and their relationship to SDI represents a robust framework on which to benchmark geography-specific health performance and SDG progress. Country-specific drivers of disease burden, particularly for causes with higher-than-expected DALYs, should inform financial and research investments, prevention efforts, health policies, and health system improvement initiatives for all countries along the development continuum.

FUNDING

Bill & Melinda Gates Foundation.

Global, regional, and national disability-adjusted life years (DALYs) for 306 diseases and injuries and healthy life expectancy (HALE) for 188 countries, 1990-2013: quantifying the epidemiological transition

BACKGROUND

The Global Burden of Disease Study 2013 (GBD 2013) aims to bring together all available epidemiological data using a coherent measurement framework, standardised estimation methods, and transparent data sources to enable comparisons of health loss over time and across causes, age-sex groups, and countries. The GBD can be used to generate summary measures such as disability-adjusted life-years (DALYs) and healthy life expectancy (HALE) that make possible comparative assessments of broad epidemiological patterns across countries and time. These summary measures can also be used to quantify the component of variation in epidemiology that is related to sociodemographic development.

METHODS

We used the published GBD 2013 data for age-specific mortality, years of life lost due to premature mortality (YLLs), and years lived with disability (YLDs) to calculate DALYs and HALE for 1990, 1995, 2000, 2005, 2010, and 2013 for 188 countries. We calculated HALE using the Sullivan method; 95% uncertainty intervals (UIs) represent uncertainty in age-specific death rates and YLDs per person for each country, age, sex, and year. We estimated DALYs for 306 causes for each country as the sum of YLLs and YLDs; 95% UIs represent uncertainty in YLL and YLD rates. We quantified patterns of the epidemiological transition with a composite indicator of sociodemographic status, which we constructed from income per person, average years of schooling after age 15 years, and the total fertility rate and mean age of the population. We applied hierarchical regression to DALY rates by cause across countries to decompose variance related to the sociodemographic status variable, country, and time.

FINDINGS

Worldwide, from 1990 to 2013, life expectancy at birth rose by 6·2 years (95% UI 5·6-6·6), from 65·3 years (65·0-65·6) in 1990 to 71·5 years (71·0-71·9) in 2013, HALE at birth rose by 5·4 years (4·9-5·8), from 56·9 years (54·5-59·1) to 62·3 years (59·7-64·8), total DALYs fell by 3·6% (0·3-7·4), and age-standardised DALY rates per 100 000 people fell by 26·7% (24·6-29·1). For communicable, maternal, neonatal, and nutritional disorders, global DALY numbers, crude rates, and age-standardised rates have all declined between 1990 and 2013, whereas for non-communicable diseases, global DALYs have been increasing, DALY rates have remained nearly constant, and age-standardised DALY rates declined during the same period. From 2005 to 2013, the number of DALYs increased for most specific non-communicable diseases, including cardiovascular diseases and neoplasms, in addition to dengue, food-borne trematodes, and leishmaniasis; DALYs decreased for nearly all other causes. By 2013, the five leading causes of DALYs were ischaemic heart disease, lower respiratory infections, cerebrovascular disease, low back and neck pain, and road injuries. Sociodemographic status explained more than 50% of the variance between countries and over time for diarrhoea, lower respiratory infections, and other common infectious diseases; maternal disorders; neonatal disorders; nutritional deficiencies; other communicable, maternal, neonatal, and nutritional diseases; musculoskeletal disorders; and other non-communicable diseases. However, sociodemographic status explained less than 10% of the variance in DALY rates for cardiovascular diseases; chronic respiratory diseases; cirrhosis; diabetes, urogenital, blood, and endocrine diseases; unintentional injuries; and self-harm and interpersonal violence. Predictably, increased sociodemographic status was associated with a shift in burden from YLLs to YLDs, driven by declines in YLLs and increases in YLDs from musculoskeletal disorders, neurological disorders, and mental and substance use disorders. In most country-specific estimates, the increase in life expectancy was greater than that in HALE. Leading causes of DALYs are highly variable across countries.

INTERPRETATION

Global health is improving. Population growth and ageing have driven up numbers of DALYs, but crude rates have remained relatively constant, showing that progress in health does not mean fewer demands on health systems. The notion of an epidemiological transition--in which increasing sociodemographic status brings structured change in disease burden--is useful, but there is tremendous variation in burden of disease that is not associated with sociodemographic status. This further underscores the need for country-specific assessments of DALYs and HALE to appropriately inform health policy decisions and attendant actions.

FUNDING

Bill & Melinda Gates Foundation.

Incidence and risk factors for venous reflux in the general population: Edinburgh Vein Study

OBJECTIVE/BACKGROUND

Chronic venous disease (CVD) is common, but the incidence of venous reflux, a precursor to this condition, is unknown. This study measured the incidence of venous reflux and associated risk factors, and examined the association between venous reflux and the incidence of CVD.

METHODS

In the Edinburgh Vein Study, a random sample of 1566 men and women aged 18-64 years were examined at baseline. Eight hundred and eighty of these patients were followed up 13 years and underwent an examination comprising clinical classification of CVD and duplex scanning of the deep and superficial systems to measure venous reflux ≥0.5 s.

RESULTS

The 13-year incidence of reflux was 12.7% (95% confidence interval [CI] 9.2-17.2), equivalent to an annual incidence of 0.9% (95% CI 0.7-1.3). The 13-year incidence of isolated superficial, isolated deep, and combined deep and superficial reflux was 8.8% (95% CI 5.6-12.0), 2.6% (95% CI 1.2-5.0), and 1.3% (95% CI 0.4-3.2), respectively. The highest incidence was in the great saphenous vein in the lower thigh (8.1%, 95% CI 5.4-11.8). There were no age or sex differences (p > .050). The risk of developing reflux was associated with being overweight (odds ratio [OR] 2.1, 95% CI 1.0-4.4) and with history of deep vein thrombosis (OR 11.3, 95% CI 1.0-132.3). Venous reflux at baseline was associated with new varicose veins at follow up (p < .001): the age- and sex-adjusted OR was 4.4 (95% CI 1.8-10.8) in those with isolated superficial reflux and 7.3 (95% CI 2.6-22.5) in those with combined deep and superficial reflux.

CONCLUSION

For every year of follow-up, around 1% of this adult population developed venous reflux. In two thirds of cases, the superficial system was affected. Venous reflux increased the risk of developing varicose veins, especially when combined deep and superficial reflux was present.

Development and validation of an ankle brachial index risk model for the prediction of cardiovascular events

BACKGROUND

The ankle brachial index (ABI) is related to risk of cardiovascular events independent of the Framingham risk score (FRS). The aim of this study was to develop and evaluate a risk model for cardiovascular events incorporating the ABI and FRS.

DESIGN

An analysis of participant data from 18 cohorts in which 24,375 men and 20,377 women free of coronary heart disease had ABI measured and were followed up for events.

METHODS

Subjects were divided into a development and internal validation dataset and an external validation dataset. Two models, comprising FRS and FRS + ABI, were fitted for the primary outcome of major coronary events.

RESULTS

In predicting events in the external validation dataset, C-index for the FRS was 0.672 (95% CI 0.599 to 0.737) in men and 0.578 (95% CI 0.492 to 0.661) in women. The FRS + ABI led to a small increase in C-index in men to 0.685 (95% CI 0.612 to 0.749) and large increase in women to 0.690 (95% CI 0.605 to 0.764) with net reclassification improvement (NRI) of 4.3% (95% CI 0.0 to 7.6%, p = 0.050) and 9.6% (95% CI 6.1 to 16.4%, p < 0.001), respectively. Restricting the FRS + ABI model to those with FRS intermediate 10-year risk of 10 to 19% resulted in higher NRI of 15.9% (95% CI 6.1 to 20.6%, p < 0.001) in men and 23.3% (95% CI 13.8 to 62.5%, p = 0.002) in women. However, incorporating ABI in an improved newly fitted risk factor model had a nonsignificant effect: NRI 2.0% (95% CI 2.3 to 4.2%, p = 0.567) in men and 1.1% (95% CI 1.9 to 4.0%, p = 0.483) in women.

CONCLUSIONS

An ABI risk model may improve prediction especially in individuals at intermediate risk and when performance of the base risk factor model is modest.

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 (β = -0.153, P < 0.01), and with an estimated decline on AVLT (β = -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.

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.).

Telangiectasia and venous reflux in the Edinburgh Vein Study

Objective

The purpose of this study was to correlate the clinical findings in the Edinburgh Vein Study with the results of duplex scanning of the deep and superficial venous systems.

Methods

An age-stratified random sample of 1566 people (699 men and 867 women) aged 16–64 were selected from computerized age–sex registers of participating practices (twelve general practices with catchment areas geographically and socioeconomically distributed throughout Edinburgh). Screening included clinical examination, photography and duplex ultrasonography of the superficial veins and the deep veins down to popliteal level. Telangiectasia and varicose veins were graded 1–3 according to severity.

Results

Since there was good agreement between the duplex findings of the right versus left legs, the current analyses are based on 1092 subjects (486 men and 606 women) with complete duplex scan data in their left legs. There was no significant trend of increasing incompetence in either the deep veins only ( P = 0.214) or in the combined deep and superficial veins ( P = 0.111) with increasing severity of the telangiectasia. There was a statistically significant trend for increasing incompetence in (a) the superficial veins ( P = 0.006) and (b) either the superficial or deep veins ( P < 0.001) to be associated with advancing grade of telangiectasia. When stratified by gender, significant trends were maintained for male superficial vein incompetence and for either superficial or deep incompetence in both genders. Examination of incompetence in individual venous segments showed that increasing severity of telangiectasia was significantly associated with an increasing proportion of reflux in the upper and lower great saphenous and femoral vein segments. There was no significant association between small saphenous incompetence and increasing grade of telangiectasia.

Conclusion

There is a significant, but not wholly consistent, association between grade of telangiectasia and reflux in both the deep and superficial systems. This association does not apply to the small saphenous system.

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.

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.

Association of retinal arteriolar dilatation with lower verbal memory: the Edinburgh Type 2 Diabetes Study

AIMS/HYPOTHESIS

Retinal vascular calibre changes may reflect early subclinical microvascular disease in diabetes. Because of the considerable homology between retinal and cerebral microcirculation, we examined whether retinal vascular calibre, as a proxy of cerebral microvascular disease, was associated with cognitive function in older people with type 2 diabetes.

METHODS

A cross-sectional analysis of 954 people aged 60-75 years with type 2 diabetes from the population-based Edinburgh Type 2 Diabetes Study was performed. Participants underwent standard seven-field binocular digital retinal photography and a battery of seven cognitive function tests. The Mill Hill Vocabulary Scale was used to estimate pre-morbid cognitive ability. Retinal vascular calibre was measured from an image field with the optic disc in the centre using a validated computer-based program.

RESULTS

After age and sex adjustment, larger retinal arteriolar and venular calibres were significantly associated with lower scores for the Wechsler Logical Memory test, with standardised regression coefficients -0.119 and -0.084, respectively (p < 0.01), but not with other cognitive tests. There was a significant interaction between sex and retinal vascular calibre for logical memory. In male participants, the association of increased retinal arteriolar calibre with logical memory persisted (p < 0.05) when further adjusted for vocabulary, venular calibre, depression, cardiovascular risk factors and macrovascular disease. In female participants, this association was weaker and not significant.

CONCLUSIONS/INTERPRETATION

Retinal arteriolar dilatation was associated with poorer memory, independent of estimated prior cognitive ability in older men with type 2 diabetes. The sex interaction with stronger findings in men requires confirmation. Nevertheless, these data suggest that impaired cerebral arteriolar autoregulation in smooth muscle cells, leading to arteriolar dilatation, may be a possible pathogenic mechanism in verbal declarative memory decrements in people with diabetes.