Network


Latest external collaboration on country level. Dive into details by clicking on the dots.

Hotspot


Dive into the research topics where Ron J. G. Peters is active.

Publication


Featured researches published by Ron J. G. Peters.


The Lancet | 2001

Effects of pretreatment with clopidogrel and aspirin followed by long-term therapy in patients undergoing percutaneous coronary intervention: the PCI-CURE study

Shamir R. Mehta; Salim Yusuf; Ron J. G. Peters; Michel E. Bertrand; Basil S. Lewis; Madhu K. Natarajan; Klas Malmberg; Hans-Jürgen Rupprecht; Feng Zhao; Susan Chrolavicius; Ingrid Copland; Keith A. A. Fox

BACKGROUND Despite the use of aspirin, there is still a risk of ischaemic events after percutaneous coronary intervention (PCI). We aimed to find out whether, in addition to aspirin, pretreatment with clopidogrel followed by long-term therapy after PCI is superior to a strategy of no pretreatment and short-term therapy for only 4 weeks after PCI. METHODS 2658 patients with non-ST-elevation acute coronary syndrome undergoing PCI in the CURE study had been randomly assigned double-blind treatment with clopidogrel (n=1313) or placebo (n=1345). Patients were pretreated with aspirin and study drug for a median of 6 days before PCI during the initial hospital admission, and for a median of 10 days overall. After PCI, most patients (>80%) in both groups received open-label thienopyridine for about 4 weeks, after which study drug was restarted for a mean of 8 months. The primary endpoint was a composite of cardiovascular death, myocardial infarction, or urgent target-vessel revascularisation within 30 days of PCI. The main analysis was by intention to treat. FINDINGS There were no drop-outs. 59 (4.5%) patients in the clopidogrel group had the primary endpoint, compared with 86 (6.4%) in the placebo group (relative risk 0.70 [95% CI 0.50-0.97], p=0.03). Long-term administration of clopidogrel after PCI was associated with a lower rate of cardiovascular death, myocardial infarction, or any revascularisation (p=0.03), and of cardiovascular death or myocardial infarction (p=0.047). Overall (including events before and after PCI) there was a 31% reduction cardiovascular death or myocardial infarction (p=0.002). There was less use of glycoprotein IIb/IIIa inhibitor in the clopidogrel group (p=0.001). At follow-up, there was no significant difference in major bleeding between the groups (p=0.64). INTERPRETATION In patients with acute coronary syndrome receiving aspirin, a strategy of clopidogrel pretreatment followed by long-term therapy is beneficial in reducing major cardiovascular events, compared with placebo.


Circulation | 2004

Benefits and Risks of the Combination of Clopidogrel and Aspirin in Patients Undergoing Surgical Revascularization for Non–ST-Elevation Acute Coronary Syndrome The Clopidogrel in Unstable angina to prevent Recurrent ischemic Events (CURE) Trial

Keith A.A. Fox; Shamir R. Mehta; Ron J. G. Peters; Feng Zhao; Nasser Lakkis; Bernard J. Gersh; Salim Yusuf

Background—Antiplatelet therapy and antithrombin therapy have been demonstrated to reduce the risk of cardiac events in patients presenting with acute coronary syndrome, yet all effective therapies also increase the risk of bleeding. Methods and Results—In the Clopidogrel in Unstable angina to prevent Recurrent ischemic Events (CURE) trial, 12 562 patients were randomized to clopidogrel or placebo in addition to aspirin, and the primary outcome was cardiovascular (CV) death, myocardial infarction (MI), or stroke. The benefits were consistent among those undergoing percutaneous coronary intervention (PCI) [9.6% for clopidogrel, 13.2% for placebo; relative risk (RR), 0.72; 95% CI, 0.57 to 0.90], coronary artery bypass grafting (CABG) surgery (14.5% for clopidogrel 16.2% for placebo; RR, 0.89; 95% CI, 0.71 to 1.11), and medical therapy only (8.1% for clopidogrel, 10.0% for placebo; RR, 0.80; 95% CI, 0.69 to 0.92; test for interaction among strata, 0.53). For CABG during the initial hospitalization (530 for placebo, 485 for clopidogrel), the frequency of CV death, MI or stroke before CABG was 4.7% for placebo and 2.9% for clopidogrel (RR, 0.56; 95% CI, 0.29 to 1.08). For the entire study, there was a 1% excess of major bleeding but no significant excess of life-threatening bleeding. Among patients undergoing CABG, the rates of life-threatening bleeding were 5.6% for clopidogrel and 4.2% for placebo (RR, 1.30; 95% CI, 0.91 to 1.95; both nonsignificant). Conclusions—The benefits versus risks of early and long-term clopidogrel therapy (freedom from CV death, MI, stroke, or life-threatening bleeding) are similar in those undergoing revascularization (CABG or PCI) and in the study population as a whole. Overall, the benefits of starting clopidogrel on admission appear to outweigh the risks, even among those who proceed to CABG during the initial hospitalization.


Circulation | 2003

Effects of Aspirin Dose When Used Alone or in Combination With Clopidogrel in Patients With Acute Coronary Syndromes Observations From the Clopidogrel in Unstable angina to prevent Recurrent Events (CURE) Study

Ron J. G. Peters; Shamir R. Mehta; Keith A.A. Fox; Feng Zhao; Basil S. Lewis; Steven L. Kopecky; Rafael Diaz; Patrick Commerford; Vicent Valentin; Salim Yusuf

Background—We studied the benefits and risks of adding clopidogrel to different doses of aspirin in the treatment of patients with acute coronary syndrome (ACS). Methods and Results—In the Clopidogrel in Unstable angina to prevent Recurrent Events (CURE) trial, 12 562 patients with ACS using aspirin, 75 to 325 mg daily, were randomized to clopidogrel or placebo for up to 1 year. In this analysis, patients were divided into the following 3 aspirin dose groups: ≤100 mg, 101 through 199 mg, and ≥200 mg. The combined incidence of cardiovascular death, myocardial infarction, or stroke was reduced by clopidogrel regardless of aspirin dose, as follows: ≤100 mg, 10.5% versus 8.6% (relative risk [RR], 0.81 [95% CI, 0.68 to 0.97]); 101 to 199 mg, 9.8% versus 9.5% (RR, 0.97 [95% CI 0.77 to 1.22]); and ≥200 mg, 13.6% versus 9.8% (RR, 0.71 [95% CI, 0.59 to 0.85]). The incidence of major bleeding increased with increasing aspirin dose both in the placebo group (1.9%, 2.8%, and 3.7%, respectively; P =0.0001) and the clopidogrel group (3.0%, 3.4%, and 4.9%, respectively; P =0.0009); thus, the excess risk with clopidogrel was 1.1%, 1.2%, and 1.2%, respectively. The adjusted hazard ratio for major bleeding for the highest versus the lowest dose of aspirin was 1.9 (95% CI 1.29 to 2.72) in the placebo group, 1.6 (95% CI 1.19 to 2.23) in the clopidogrel group, and 1.7 (95% CI 1.36 to 2.20) in the combined group. Conclusions—In patients with ACS, adding clopidogrel to aspirin is beneficial regardless of aspirin dose. Bleeding risks increase with increasing aspirin dose, with or without clopidogrel, without any increase in efficacy. Our findings suggest that the optimal daily dose of aspirin may be between 75 and 100 mg, with or without clopidogrel.


Circulation | 2002

Ability of recombinant factor VIIa to reverse the anticoagulant effect of the pentasaccharide fondaparinux in healthy volunteers.

Nick R. Bijsterveld; Arno H Moons; S. Matthijs Boekholdt; Benien E. van Aken; Hein Fennema; Ron J. G. Peters; Joost C. M. Meijers; Harry R. Buller; Marcel Levi

Background—The novel anticoagulant fondaparinux proved to be effective and safe in the postoperative prevention of venous thrombosis. Current phase III trials with this synthetic selective factor Xa inhibitor focus on its use in the treatment of patients with venous and arterial thrombosis. As with any anticoagulant therapy, there is a risk of bleeding complications; hence, a strategy to reverse the effects of fondaparinux is desirable. The aim of this study was to investigate whether recombinant factor VIIa (rFVIIa) could neutralize the anticoagulant effects of subcutaneously administered fondaparinux. Methods and Results—In a randomized, placebo-controlled design, 16 healthy male subjects received either a single subcutaneous dose of fondaparinux (10 mg) and a single intravenous bolus of rFVIIa (90 &mgr;g/kg; n=8), fondaparinux and placebo (n=4), or placebo and rFVIIa (n=4). Fondaparinux (or placebo) was administered 2 hours before rFVIIa (or placebo). Injection of rFVIIa after fondaparinux normalized the prolonged activated partial thromboplastin and prothrombin times and reversed the decrease in prothrombin activation fragments 1+2 (F1+2), as observed with fondaparinux alone. Thrombin-generation time and endogenous thrombin potential, which were inhibited by fondaparinux, normalized up to 6 hours after rFVIIa injection. Conclusions—rFVIIa is capable of normalizing coagulation times and thrombin generation during fondaparinux treatment. The duration of this effect ranged from 2 to 6 hours after rFVIIa injection. These results suggest that rFVIIa may be useful to reverse the anticoagulant effect of fondaparinux in case of serious bleeding complications or need for acute surgery during treatment with fondaparinux.


The New England Journal of Medicine | 2016

Blood-pressure lowering in intermediate-risk persons without cardiovascular disease

Eva Lonn; Jackie Bosch; Patricio López-Jaramillo; Jun Zhu; Lisheng Liu; Prem Pais; Rafael Diaz; Denis Xavier; Karen Sliwa; Antonio L. Dans; Alvaro Avezum; Leopoldo Soares Piegas; Katalin Keltai; Matyas Keltai; Chazova Ie; Ron J. G. Peters; Claes Held; Khalid Yusoff; Basil S. Lewis; Petr Jansky; Alexander Parkhomenko; Kamlesh Khunti; William D. Toff; Christopher M. Reid; John Varigos; Lawrence A. Leiter; Dora I. Molina; Robert S. McKelvie; Janice Pogue; Joanne Wilkinson

BACKGROUND Antihypertensive therapy reduces the risk of cardiovascular events among high-risk persons and among those with a systolic blood pressure of 160 mm Hg or higher, but its role in persons at intermediate risk and with lower blood pressure is unclear. METHODS In one comparison from a 2-by-2 factorial trial, we randomly assigned 12,705 participants at intermediate risk who did not have cardiovascular disease to receive either candesartan at a dose of 16 mg per day plus hydrochlorothiazide at a dose of 12.5 mg per day or placebo. The first coprimary outcome was the composite of death from cardiovascular causes, nonfatal myocardial infarction, or nonfatal stroke; the second coprimary outcome additionally included resuscitated cardiac arrest, heart failure, and revascularization. The median follow-up was 5.6 years. RESULTS The mean blood pressure of the participants at baseline was 138.1/81.9 mm Hg; the decrease in blood pressure was 6.0/3.0 mm Hg greater in the active-treatment group than in the placebo group. The first coprimary outcome occurred in 260 participants (4.1%) in the active-treatment group and in 279 (4.4%) in the placebo group (hazard ratio, 0.93; 95% confidence interval [CI], 0.79 to 1.10; P=0.40); the second coprimary outcome occurred in 312 participants (4.9%) and 328 participants (5.2%), respectively (hazard ratio, 0.95; 95% CI, 0.81 to 1.11; P=0.51). In one of the three prespecified hypothesis-based subgroups, participants in the subgroup for the upper third of systolic blood pressure (>143.5 mm Hg) who were in the active-treatment group had significantly lower rates of the first and second coprimary outcomes than those in the placebo group; effects were neutral in the middle and lower thirds (P=0.02 and P=0.009, respectively, for trend in the two outcomes). CONCLUSIONS Therapy with candesartan at a dose of 16 mg per day plus hydrochlorothiazide at a dose of 12.5 mg per day was not associated with a lower rate of major cardiovascular events than placebo among persons at intermediate risk who did not have cardiovascular disease. (Funded by the Canadian Institutes of Health Research and AstraZeneca; ClinicalTrials.gov number, NCT00468923.).


Circulation | 2004

Plasma Levels of Cholesteryl Ester Transfer Protein and the Risk of Future Coronary Artery Disease in Apparently Healthy Men and Women: The Prospective EPIC (European Prospective Investigation into Cancer and nutrition)–Norfolk Population Study

S. Matthijs Boekholdt; Jan-Albert Kuivenhoven; Nicholas J. Wareham; Ron J. G. Peters; J. Wouter Jukema; Robert Luben; Sheila Bingham; Nicholas E. Day; John J. P. Kastelein; Kay-Tee Khaw

Background—Low plasma levels of cholesteryl ester transfer protein (CETP) are associated with elevated levels of HDL cholesterol (HDL-C), but it remains unclear whether this translates into a concomitant reduction in the risk of coronary artery disease (CAD). Evidence exists that the effect of CETP depends on metabolic context, in particular on triglyceride levels. Methods and Results—A nested case-control study was performed in the prospective EPIC-Norfolk cohort study. Cases were apparently healthy men and women aged 45 to 79 years who developed fatal or nonfatal CAD during follow-up. Control subjects were matched by age, sex, and enrollment time. CETP levels were not significantly different between cases and controls (4.0±2.2 versus 3.8±2.1 mg/L, P=0.07). CETP levels were significantly related to plasma levels of total cholesterol, LDL cholesterol, and HDL-C. The risk of CAD increased with increasing CETP quintiles (P for linearity=0.02), such that subjects in the highest quintile had an adjusted OR of 1.43 (95% CI 1.03 to 1.99, P=0.03) versus those in the lowest. Among individuals with triglyceride levels below the median (1.7 mmol/L), no relationship between CETP levels and CAD risk was observed (P for linearity=0.5), but this relationship was strong among those with high triglyceride levels (P for linearity=0.02), such that those in the highest CETP quintile had an OR of 1.87 (95% CI 1.06 to 3.30, P=0.02). Conclusions—Elevated CETP levels are associated with an increasing risk of future CAD in apparently healthy individuals, but only in those with high triglyceride levels.


The New England Journal of Medicine | 2016

Cholesterol Lowering in Intermediate-Risk Persons without Cardiovascular Disease.

Salim Yusuf; Jackie Bosch; G. Dagenais; Jun-Ren Zhu; Denis Xavier; Lisheng Liu; Prem Pais; Patricio López-Jaramillo; Lawrence A. Leiter; Antonio L. Dans; Alvaro Avezum; Leopoldo Soares Piegas; Alexandr Parkhomenko; Katalin Keltai; Matyas Keltai; Karen Sliwa; Ron J. G. Peters; Claes Held; Chazova Ie; K. Yusoff; Basil S. Lewis; Petr Jansky; Kamlesh Khunti; William D. Toff; Christopher M. Reid; John Varigos; G. Sanchez-Vallejo; Robert S. McKelvie; Janice Pogue; Hyejung Jung

BACKGROUND Previous trials have shown that the use of statins to lower cholesterol reduces the risk of cardiovascular events among persons without cardiovascular disease. Those trials have involved persons with elevated lipid levels or inflammatory markers and involved mainly white persons. It is unclear whether the benefits of statins can be extended to an intermediate-risk, ethnically diverse population without cardiovascular disease. METHODS In one comparison from a 2-by-2 factorial trial, we randomly assigned 12,705 participants in 21 countries who did not have cardiovascular disease and were at intermediate risk to receive rosuvastatin at a dose of 10 mg per day or placebo. The first coprimary outcome was the composite of death from cardiovascular causes, nonfatal myocardial infarction, or nonfatal stroke, and the second coprimary outcome additionally included revascularization, heart failure, and resuscitated cardiac arrest. The median follow-up was 5.6 years. RESULTS The overall mean low-density lipoprotein cholesterol level was 26.5% lower in the rosuvastatin group than in the placebo group. The first coprimary outcome occurred in 235 participants (3.7%) in the rosuvastatin group and in 304 participants (4.8%) in the placebo group (hazard ratio, 0.76; 95% confidence interval [CI], 0.64 to 0.91; P=0.002). The results for the second coprimary outcome were consistent with the results for the first (occurring in 277 participants [4.4%] in the rosuvastatin group and in 363 participants [5.7%] in the placebo group; hazard ratio, 0.75; 95% CI, 0.64 to 0.88; P<0.001). The results were also consistent in subgroups defined according to cardiovascular risk at baseline, lipid level, C-reactive protein level, blood pressure, and race or ethnic group. In the rosuvastatin group, there was no excess of diabetes or cancers, but there was an excess of cataract surgery (in 3.8% of the participants, vs. 3.1% in the placebo group; P=0.02) and muscle symptoms (in 5.8% of the participants, vs. 4.7% in the placebo group; P=0.005). CONCLUSIONS Treatment with rosuvastatin at a dose of 10 mg per day resulted in a significantly lower risk of cardiovascular events than placebo in an intermediate-risk, ethnically diverse population without cardiovascular disease. (Funded by the Canadian Institutes of Health Research and AstraZeneca; HOPE-3 ClinicalTrials.gov number, NCT00468923.).


Circulation | 2003

Variants of Toll-Like Receptor 4 Modify the Efficacy of Statin Therapy and the Risk of Cardiovascular Events

S. Matthijs Boekholdt; Willem R.P. Agema; Ron J. G. Peters; Aeilko H. Zwinderman; Ernst E. van der Wall; Pieter H. Reitsma; John J. P. Kastelein; J. Wouter Jukema

Background—Atherosclerosis is increasingly considered to be a chronic inflammatory process. We examined whether genetic variants of the toll-like receptor 4 (TLR4), which are correlated with impaired innate immunity and with progression of carotid atherosclerosis, are also associated with coronary atherosclerosis and predict the risk of cardiovascular events. Methods and Results—Two polymorphisms of the TLR4 gene (Asp299Gly and Thr399Ile) were determined in 655 men with angiographically documented coronary atherosclerosis. All patients participated in a prospective cholesterol-lowering trial evaluating the effect on coronary artery disease and were randomly assigned to either pravastatin or placebo for 2 years. There were no significant differences between genetically defined subgroups with respect to baseline risk factors, treatment, or in-trial changes of lipid, lipoprotein, or angiographic measurements. Genotype was not associated with progression of atherosclerosis. In the pravastatin group, 299Gly carriers had a lower risk of cardiovascular events during follow-up than noncarriers (2.0% versus 11.5%, P =0.045). Among noncarriers, pravastatin reduced the risk of cardiovascular events from 18.1% to 11.5% (P =0.03), whereas among 299Gly carriers this risk was strikingly reduced from 29.6% to 2.0% (P =0.0002, P =0.025 for interaction). Conclusions—Among symptomatic men with documented coronary artery disease, the TLR4 Asp299Gly polymorphism was associated with the risk of cardiovascular events. This variant also modified the efficacy of pravastatin in preventing cardiovascular events, such that carriers of the variant allele had significantly more benefit from pravastatin treatment.


Arteriosclerosis, Thrombosis, and Vascular Biology | 2004

IL-8 plasma concentrations and the risk of future coronary artery disease in apparently healthy men and women - The EPIC-Norfolk prospective population study

S. Matthijs Boekholdt; Ron J. G. Peters; C. Erik Hack; Nicholas E. Day; Robert Luben; Sheila Bingham; Nicholas J. Wareham; Pieter H. Reitsma; Kay-Tee Khaw

Objective—To study the role of IL-8 in predicting future coronary artery disease (CAD) in apparently healthy men and women. Methods and Results—A nested case-control study was performed in the prospective EPIC-Norfolk population study. We measured baseline IL-8 concentrations among 785 apparently healthy individuals in whom fatal or nonfatal CAD developed during follow-up and 1570 matched controls. Baseline IL-8 concentrations were higher in cases than in matched controls (3.5 pg/mL versus 3.1 pg/mL, P = 0.001). The risk of future CAD increased with increasing quartiles of IL-8 (P linearity < 0.0001). Among individuals in the highest IL-8 quartile, the unadjusted odds ratio for future CAD was 1.72 (95% CI, 1.34 to 2.21; P < 0.0001). The odds ratio for future CAD was still significant after adjustment for traditional risk factors (OR, 1.58; 95%CI, 1.19 to 2.09; P = 0.002) and after additional adjustment for C-reactive protein and white cell count (OR, 1.77; 95% CI, 1.21 to 2.60; P = 0.001). Conclusions—We conclude that among apparently healthy men and women, elevated levels of IL-8 are associated with an increased risk of future CAD. These prospective data support a role for IL-8 in the development of CAD events.


European Heart Journal | 2008

Improving clinical outcomes by reducing bleeding in patients with non-ST-elevation acute coronary syndromes.

Andrzej Budaj; John W. Eikelboom; Shamir R. Mehta; Rizwan Afzal; Susan Chrolavicius; Jean-Pierre Bassand; Keith A.A. Fox; Lars Wallentin; Ron J. G. Peters; Christopher B. Granger; Campbell D. Joyner; Salim Yusuf

AIMS Bleeding in patients with coronary artery disease has been linked with adverse outcomes. We examined the incidence and outcomes after bleeding in 20 078 patients with acute coronary syndromes (ACS) enrolled in the OASIS-5 trial who were treated with fondaparinux or the low-molecular weight heparin, enoxaparin. METHODS AND RESULTS Nine hundred and ninety (4.9%) patients developed major bleeding and 423 (2.1%) developed minor bleeding. Fondaparinux compared with enoxaparin reduced fatal bleeding [0.07 vs. 0.22%, relative risk (RR) 0.30, 95% CI: 0.13-0.71], non-fatal major bleeding (2.2 vs. 4.2%, RR 0.52, 95% CI: 0.44-0.61), minor bleeding (1.1 vs. 3.2%, RR 0.34, 95% CI: 0.27-0.42), and need for transfusion (1.8 vs. 3.1%, RR 0.56, 95% CI: 0.47-0.61) during the first 9 days. One of every six deaths during the first 30 days occurred in patients who experienced bleeding. Cox proportional hazards model revealed that major bleeding was associated with about a four-fold increased hazard of death, myocardial infarction, or stroke during the first 30 days and about a three-fold increased hazard during 180 days of follow up. CONCLUSION Bleeding in patients with ACS is a powerful determinant of fatal and non-fatal outcomes. Reducing the risk of bleeding using a safer anticoagulant strategy during the first 9 days is associated with substantial reductions in morbidity and mortality.

Collaboration


Dive into the Ron J. G. Peters's collaboration.

Top Co-Authors

Avatar
Top Co-Authors

Avatar

Jan J. Piek

University of Amsterdam

View shared research outputs
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar

Salim Yusuf

Population Health Research Institute

View shared research outputs
Top Co-Authors

Avatar
Top Co-Authors

Avatar

Marcel Levi

University of Amsterdam

View shared research outputs
Top Co-Authors

Avatar

Shamir R. Mehta

Population Health Research Institute

View shared research outputs
Researchain Logo
Decentralizing Knowledge