In-silico trial emulation to predict the cardiovascular protection of new lipid-lowering drugs: an illustration through the design of the SIRIUS programme.

INTRODUCTION: Inclisiran, an siRNA targeting hepatic PCSK9 mRNA, administered twice-yearly (after initial and 3-month doses), substantially and sustainably reduced LDL-cholesterol (LDL-C) in Phase III trials. Whether lowering LDL-C with inclisiran translates into a reduced risk of major adverse cardiovascular events (MACE) is not yet established. In-silico trials applying a disease computational model to virtual patients receiving new treatments allow to emulate large scale long term clinical trials. The SIRIUS in-silico trial programme aims to predict the efficacy of inclisiran on CV events in individuals with established atherosclerotic cardiovascular disease (ASCVD). METHODS: A knowledge-based mechanistic model of ASCVD was built, calibrated, and validated to conduct the SIRIUS programme (NCT05974345) aiming to predict the effect of inclisiran on CV outcomes.The SIRIUS Virtual Population included patients with established ASCVD (previous myocardial infarction (MI), previous ischemic stroke (IS), previous symptomatic lower limb peripheral arterial disease (PAD) defined as either intermittent claudication with ankle-brachial index <0.85, prior peripheral arterial revascularization procedure, or vascular amputation) and fasting LDL-C ≥ 70 mg/dL, despite stable (≥ 4 weeks) well-tolerated lipid lowering therapies.SIRIUS is an in-silico multi-arm trial programme. It follows an idealized crossover design where each virtual patient is its own control, comparing inclisiran to 1) placebo as adjunct to high-intensity statin therapy with or without ezetimibe, 2) ezetimibe as adjunct to high-intensity statin therapy, 3) evolocumab as adjunct to high-intensity statin therapy and ezetimibe.The co-primary efficacy outcomes are based on time to the first occurrence of any component of 3P-MACE (composite of CV death, nonfatal MI or nonfatal IS) and time to occurrence of CV death over 5 years. PERSPECTIVES/CONCLUSION: The SIRIUS in-silico trial programme will provide early insights regarding a potential effect of inclisiran on MACE in ASCVD patients, several years before the availability of the results from ongoing CV outcomes trials (ORION-4 and VICTORION-2-P).

The SIRIUS in-silico trial programme is a knowledge-based computer model built to simulate the biological and clinical long-term effects of inclisiran, an siRNA targeting hepatic PCSK9 mRNA, on virtual patients with cardiovascular disease. Key Findings: The model accurately replicates the biological processes of cardiovascular disease and the impact of lipid-lowering therapies, allowing for the prediction of randomized clinical trials.Simulating clinical trials with virtual patients can provide insights into the efficacy and safety of new treatments before the results of randomized clinical trials, potentially speeding up the drug development process.

Baseline characteristics of the patient population in the Saxagliptin Assessment of Vascular Outcomes Recorded in patients with diabetes mellitus (SAVOR)-TIMI 53 trial.

BACKGROUND AND AIMS: SAVOR-TIMI 53 was designed to study the effects of the DPP-4 inhibitor saxagliptin on cardiovascular outcomes in high risk type 2 diabetes patients with diverse levels of diabetes control and background anti-diabetic drugs. The goal of this article is to describe the baseline characteristics of this hypothesis driven study. MATERIALS AND METHODS: A total of 16 496 diabetic patients from North America (31.9%), Western Europe (26.0%), Eastern Europe (17.3%), Latin America (16.4%) and Asia (8.3%), with either established cardiovascular disease (78.3%) or with ≥two additional cardiovascular risk factors (21.7%) were randomised to saxagliptin or placebo. Biomarkers of inflammation and insulin resistance were taken at baseline and 2 years later in order to correlate saxagliptin effect on cardiovascular outcome to its effect on inflammation and insulin resistance. RESULTS: Mean [+/-standard deviation (SD)] age was 65.0 (+/-8.6) years, 66.9% were male, body mass index was 31.2 kg/m² (+/-5.6), mean diabetes duration was 11.9 years (+/-8.9) and the mean HbA1c 8.0% (+/-1.4%). HbA1c < 7% was most prevalent among North Americans (30.8%) and least among Asians (15.1%), whereas HbA1c > 9% was 30.7% in Latin America 27.0% in Asia and 15.1% in North America. Diabetic retinopathy was reported in 12.3% of patients, nephropathy in 17.7% and amputation in 2.5%. Diabetic treatments categories were as follows: no medication (5.4%), 1 oral anti-diabetic drug (OAD) (25.0%), ≥2 OAD (27.7%) and/or insulin (40.9%). The prevalence of micro-albuminuria was twice as high among insulin users compared with users of ≥2 OAD. Baseline statin use (78.3% overall) varied by region. CONCLUSION: The SAVOR-TIMI 53 patient population, with differing background diabetes control and anti-diabetic treatment, provides global representation of diabetic patients with established cardiovascular disease or at high risk for cardiovascular disease and is well-positioned to determine the effect of saxagliptin on cardiovascular events.

Two-year vascular hospitalisation rates and associated costs in patients at risk of atherothrombosis in France and Germany: highest burden for peripheral arterial disease.

OBJECTIVES: To obtain Western European perspectives on the economic burden of atherothrombosis in patients with multiple risk factors only (MRF), cerebrovascular disease (CVD), coronary artery disease (CAD), and in the under-evaluated group of patients with peripheral arterial disease (PAD), we examined vascular-related hospitalisation rates and associated costs in France and Germany. DESIGN: The prospective REACH Registry enrolled 4693 patients in France, and 5594 patients in Germany (from December 2003 until June 2004). METHODS: For each country, 2-year rates and costs associated with cardiovascular events and vascular-related hospitalisations were examined for patients with MRF, CVD, CAD, and PAD. RESULTS: Two-year hospitalisation costs were highest for patients with PAD (3182.1€ for France; 2724.4€ for Germany) and lowest for the MRF group (749.1€ for France; 503.3€ for Germany). Peripheral revascularizations and amputations were the greatest contributors to costs for all risk groups. Across all PAD subgroups, peripheral procedures constituted approximately half of the 2-year costs. CONCLUSION: Hospitalisation rates and costs associated with atherothrombotic disease in France and Germany are high, especially so for patients with PAD.

Impact of preoperative maintenance or interruption of aspirin on thrombotic and bleeding events after elective non-cardiac surgery: the multicentre, randomized, blinded, placebo-controlled, STRATAGEM trial.

BACKGROUND: Patients receiving anti-platelet agents for secondary cardiovascular prevention frequently require non-cardiac surgery. A substantial proportion of these patients have their anti-platelet drug discontinued before operation; however, there is uncertainty about the impact of this practice. The aim of this study was to compare the effect of maintenance or interruption of aspirin before surgery, in terms of major thrombotic and bleeding events. METHODS: Patients treated with anti-platelet agents for secondary prevention and undergoing intermediate- or high-risk non-cardiac surgery were included in this multicentre, randomized, placebo-controlled, trial. We substituted non-aspirin anti-platelets with aspirin (75 mg daily) or placebo starting 10 days before surgery. The primary outcome was a composite score evaluating both major thrombotic and bleeding adverse events occurring within the first 30 postoperative days weighted by their severity (weights were established a priori using a Delphi consensus process). Analyses followed the intention-to-treat principle. RESULTS: We randomized 291 patients (n=145, aspirin group, and n=146, placebo group). The most frequent surgical procedures were orthopaedic surgery (52.2%), abdominal surgery (20.6%), and urologic surgery (15.5%). No significant difference was observed neither in the primary outcome score [mean values (SD)=0.67 (2.05) in the aspirin group vs 0.65 (2.04) in the placebo group, P=0.94] nor at day 30 in the number of major complications between groups. CONCLUSIONS: In these at-risk patients undergoing elective non-cardiac surgery, we did not find any difference in terms of occurrence of major thrombotic or bleeding events between preoperative maintenance or interruption of aspirin.

Predicting 10-year risk of recurrent cardiovascular events andcardiovascular interventions in patients with established cardiovascular disease: results from UCC-SMART and REACH.

BACKGROUND: Existing cardiovascular risk scores for patients with established cardiovascular disease (CVD) estimate residual risk of recurrent major cardiovascular events (MACE). The aim of the current study is to develop and externally validate a prediction model to estimate the 10-year combined risk of recurrent MACE and cardiovascular interventions (MACE+) in patients with established CVD. METHODS: Data of patients with established CVD from the UCC-SMART cohort (N = 8421) were used for model development, and patient data from REACH Western Europe (N = 14,528) and REACH North America (N = 19,495) for model validation. Predictors were selected based on the existing SMART risk score. A Fine and Gray competing risk-adjusted 10-year risk model was developed for the combined outcome MACE+. The model was validated in all patients and in strata of coronary heart disease (CHD), cerebrovascular disease (CeVD), peripheral artery disease (PAD). RESULTS: External calibration for 2-year risk in REACH Western Europe and REACH North America was good, c-statistics were moderate: 0.60 and 0.58, respectively. In strata of CVD at baseline good external calibration was observed in patients with CHD and CeVD, however, poor calibration was seen in patients with PAD. C-statistics for patients with CHD were 0.60 and 0.57, for patients with CeVD 0.62 and 0.61, and for patients with PAD 0.53 and 0.54 in REACH Western Europe and REACH North America, respectively. CONCLUSIONS: The 10-year combined risk of recurrent MACE and cardiovascular interventions can be estimated in patients with established CHD or CeVD. However, cardiovascular interventions in patients with PAD could not be predicted reliably.

Worse blood pressure control in patients with cerebrovascular or peripheral arterial disease compared with coronary artery disease.

OBJECTIVES: Poor blood pressure (BP) control is common amongst patients with symptomatic atherothrombotic disease. It is unclear whether BP control and management differ across atherothrombotic disease subtypes. METHODS: We analysed the baseline data of 44,984 patients with documented coronary artery disease (CAD) only (n = 30,414), cerebrovascular disease (CVD) only (n = 11,359) and peripheral arterial disease (PAD) only (n = 3211) from the international REduction of Atherothrombosis for Continued Health Registry and investigated the impact of atherothrombotic disease subtype on BP control and use of antihypertensive drugs. RESULTS: The proportion of patients with BP controlled (<140/90 mmHg) was higher in CAD (58.1%) than in CVD (44.8%) or PAD (38.9%) patients (P < 0.001). Amongst patients with treated hypertension, CAD patients were more likely to have BP controlled than were CVD patients [odds ratio (OR) = 1.67; 95% confidence interval (CI) = 1.59-1.75] or PAD (OR = 2.30; 95% CI = 2.10-2.52). These differences were smaller in women than in men and decreased with age. Amongst treated patients, CAD patients were more likely to receive > or =3-drug combination therapies than were CVD (OR = 1.73; 95% CI = 1.64-1.83) or PAD (OR = 1.64; 95% CI = 1.49-1.80) patients. Adjustment for age, gender, waist obesity, diabetes, education level and world region did not alter the results. CONCLUSIONS: Coronary artery disease patients are more likely than CVD or PAD patients to have BP controlled and to receive antihypertensive drugs, particularly combination therapies. Promotion of more effective BP control through combination antihypertensive therapies could improve secondary prevention and therefore prevent complications in CVD and PAD patients.

Clinical characteristics and outcomes of COMPASS eligible patients in France. An analysis from the REACH Registry.

BACKGROUND: Following the publication of the COMPASS trial, the European Medicines Agency has approved a regimen of combination of rivaroxaban 2.5mg twice daily and a daily dose of 75-100mg acetylsalicylic acid (ASA) for patients with coronary artery disease (CAD) or symptomatic peripheral artery disease (PAD) at high risk of ischemic events. However, the applicability of such a therapeutic strategy in France is currently unknown. AIMS: To describe the proportion of patients eligible to COMPASS in France, their baseline clinical characteristics and the rate of major adverse cardiovascular events, using the REACH registry. METHODS: From the the REduction of Atherothrombosis for Continued Health (REACH) registry database, a large international registry of patients with, or at risk, of atherothrombosis, we analyzed patients included in France with either established CAD and/or PAD and fulfilling the inclusion and exclusion criteria of the COMPASS trial. The ischemic outcome was a composite of cardiovascular (CV) death, myocardial infarction (MI), or stroke, and serious bleeding were defined as haemorrhagic stroke or bleeding leading to hospitalization or transfusion. RESULTS: Among more than 65000 patients enrolled in REACH, 2.012 patients were evaluable and enrolled in France. Among them, 1194 patients (59.3%) were eligible to COMPASS. The main reasons for exclusion of the COMPASS trial, were high bleeding risk (59.1%), anticoagulant use (43.4%), requirement for dual antiplatelet therapy within 1 year of an ACS or PCI (24.7%). In the "COMPASS eligible population", the rate of MACE (CV, MI and stroke) at 4 years follow-up was 13.4% [11.3-15.8], and serious bleeding was 2.5% at 4 years [1.6-3.4]. Patients with polyvascular disease (n=219) had the highest rate of MACE, compared with patients with CAD only and PAD only (19.1% [13.9-26.1] vs. 11.6% [9.1-14.8] vs 13.2% [9.2-18.8], P<0.0001, respectively). CONCLUSION: The COMPASS therapeutic strategy in France appears to be applicable to more than half of CAD or PAD patients. This population appears at high residual risk of atherothrombotic events, and patients with polyvascular disease experienced the highest rate of events.

Blood transfusion and ischaemic outcomes according to anemia and bleeding in patients with non-ST-segment elevation acute coronary syndromes: Insights from the TAO randomized clinical trial.

BACKGROUND: The benefits and risks of blood transfusion in patients with acute myocardial infarction who are anemic or who experience bleeding are debated. We sought to study the association between blood transfusion and ischemic outcomes according to haemoglobin nadir and bleeding status in patients with NST-elevation myocardial infarction (NSTEMI). METHODS: The TAO trial randomized patients with NSTEMI and coronary angiogram scheduled within 72h to heparin plus eptifibatide versus otamixaban. After exclusion of patients who underwent coronary artery bypass surgery, patients were categorized according to transfusion status considering transfusion as a time-varying covariate. The primary ischemic outcome was the composite of all-cause death or MI within 180 days of randomization. Subgroup analyses were performed according to pre-transfusion hemoglobin nadir and bleeding status. RESULTS: 12,547 patients were enrolled. Among these, blood transfusion was used in 489 (3.9%) patients. Patients who received transfusion had a higher rate of death or MI (29.9% vs. 8.1%, p<0.01). This excess risk persisted after adjustment on GRACE score and nadir of hemoglobin (HR 3.36 95%CI 2.63-4.29 p<0.01). Subgroup analyses showed that blood transfusion was associated with a higher risk in patients without overt bleeding (adjusted HR 6.25 vs. 2.85; p-interaction 0.001) as well as in those with hemoglobin nadir > 9.0 g/dl (HR 4.01; p-interaction<0.0001). CONCLUSION: In patients with NSTEMI, blood transfusion was associated with an overall increased risk of ischaemic events. However, this was mainly driven by patients without overt bleeding and those hemoglobin nadir > 9.0g/dl. This suggests possible harm of transfusion in those groups.

High cardiovascular event rates in patients with asymptomatic carotid stenosis: the REACH Registry.

BACKGROUND AND PURPOSE: Data on current cardiovascular event rates in patients with asymptomatic carotid artery stenosis (ACAS) are sparse. We compared the 1-year outcomes of patients with ACAS > or =70% versus patients without ACAS in an international, prospective cohort of outpatients with or at risk of atherothrombosis. METHODS: The Reduction of Atherothrombosis for Continued Health Registry enrolled patients with either > or =3 atherothrombotic risk factors or established atherothrombotic disease. We investigated the 1-year follow-up data of patients for whom physicians reported presence/absence of ACAS at the time of inclusion. RESULTS: Compared with patients without ACAS (n = 30 329), patients with ACAS (n = 3164) had higher age- and sex-adjusted 1-year rates of transient ischaemic attack (3.51% vs. 1.61%, P < 0.0001), non-fatal stroke (2.65% vs. 1.75%, P = 0.0009), fatal stroke (0.49% vs. 0.26%, P = 0.04), cardiovascular death (2.29% vs. 1.52%, P = 0.002), the composite end-point cardiovascular death/myocardial infarction/stroke (6.03% vs. 4.29%, P < 0.0001) and bleeding events (1.41% vs. 0.81%, P = 0.002). In patients with ACAS, Cox regression analyses identified history of cerebrovascular ischaemic events as most important predictor of future stroke (HR 3.21, 95% CI 1.82-5.65, P < 0.0001). CONCLUSION: Asymptomatic carotid artery stenosis was associated with high 1-year rates of cardiovascular and cerebrovascular ischaemic events. Stroke was powerfully predicted by prior cerebrovascular ischaemic events.

[Cardiac diffusion MRI of recent and chronic myocardial infarction: preliminary results]. / IRM de diffusion cardiaque dans l'infarctus du myocarde récent et chronique: expérience préliminaire.

PURPOSE: To use diffusion weighted MR imaging (DWI), a technique routinely used in patients with stroke, for diagnosis of myocardial infarction (MI). MATERIALS AND METHODS: A breath hold ECG gated DWI sequence (b = 300 sec/mm2) was developped and applied to 7 patients with recent MI (3-15 days), 3 patients with chronic MI (> 6 months) and 4 patients with valvular heart disease without MI (control cases). DWI data were correlated to T2W, first pass perfusion and delayed enhancement data. RESULTS: In all patients with recent MI, DWI showed an area of increased signal with reduction of ADC relative to normal myocardium. Hyperintense lesion on DWI corresponded to areas of delayed enhancement. The diffusion images were normal in patients with chronic MI or no MI. CONCLUSION: Even though no animal model or other reference method is available, these preliminary results indicate that DWI could assist clinicians in detecting recent MI.

The BEAUTIFUL study: randomized trial of ivabradine in patients with stable coronary artery disease and left ventricular systolic dysfunction - baseline characteristics of the study population.

OBJECTIVES: Ivabradine is a selective heart rate-lowering agent that acts by inhibiting the pacemaker current If in sinoatrial node cells. Patients with coronary artery disease and left ventricular dysfunction are at high risk of death and cardiac events, and the BEAUTIFUL study was designed to evaluate the effects of ivabradine on outcome in such patients receiving optimal medical therapy. This report describes the study population at baseline. METHODS: BEAUTIFUL is an international, multicentre, randomized, double-blind trial to compare ivabradine with placebo in reducing mortality and cardiovascular events in patients with stable coronary artery disease and left ventricular systolic dysfunction (ejection fraction <40%). RESULTS: A total of 10,917 patients were randomized. At baseline, their mean age was 65 years, 83% were male, 98% Caucasian, 88% had previous myocardial infarction, 37% had diabetes, and 40% had metabolic syndrome. Mean ejection fraction was 32% and resting heart rate was 71.6 bpm. Concomitant medications included beta-blockers (87%), renin-angiotensin system agents (89%), antithrombotic agents (94%), and lipid-lowering agents (76%). CONCLUSIONS: Main results from BEAUTIFUL are expected in 2008, and should show whether ivabradine, on top of optimal medical treatment, reduces mortality and cardiovascular events in this population of high-risk patients.

[Acute pericarditis in the modern era: a diagnostic challenge]. / La péricardite aiguë en 2007: un défi diagnostique.

BACKGROUND: Diagnosis of acute pericarditis remains difficult in clinical practice. OBJECTIVES: The purpose of this study was to evaluate the clinical and biological features of patients presenting with acute pericarditis, and to determine the incidence and significance of troponin I (cTnI) elevation in that context. PATIENTS AND METHODS: We retrospectively included 55 patients with acute idiopathic pericarditis. We analyzed clinical presentation, ECG recordings, biologic results, echocardiography findings and cTnI level. RESULTS: Fifty-five consecutive patients (41 men, 54+/-18 years) with idiopathic acute pericarditis were included. There was a typical chest pain in 90% of cases, whereas fever and pericardial friction rub were present in 25 and 18%, respectively. ST-segment elevation was observed in 58% of the patients. A rise of cTnI and C-reactive protein was detectable in 27 and 78% of cases respectively. The following characteristics were more frequently associated with a positive cTnI test: younger patients, recent infection and higher length-of-stay. Pericardial effusion was observed in 58% of patients. Cardiac tamponade and ventricular tachycardia both occurred in 3 patients (5%). After a mean follow-up of 33 months, recurrent pericarditis occurred in 13% of patients. A similar rate of complications was found in patients with a positive or a negative cTnI. CONCLUSION: Clinical spectra of acute pericarditis have changed and some classic assumptions and descriptions, perpetuated in some publications, are outdated. Clinical presentation implies a 45-55 year-old man, with a chest pain and ST-segment elevation, without fever or pericardial friction rub, and a positive cTnI test in 27% of cases. Therefore, misinterpretation as other disease, especially acute myocardial infarction, is common and diagnosis of acute pericarditis remains often retrospective. In our series, a cTnI rise did not appear as a negative prognostic marker.

Low-efficiency of percutaneous adenovirus-mediated arterial gene transfer in the atherosclerotic rabbit.

Recombinant adenoviruses are the most efficient vectors with which to perform arterial gene transfer. Previous in vivo studies of adenovirus-mediated arterial transfection, however, have been performed using normal or endothelium-denuded arteries. It is unclear whether these results can be extended to atherosclerotic arteries. Accordingly, this study was designed to (a) assess the feasibility of adenovirus-mediated gene transfer to atherosclerotic lesions, and (b) compare the transfection efficiency, anatomic distribution of transfected cells, and duration of transgene expression achieved in normal versus atherosclerotic arteries. A recombinant adenovirus including a nuclear-targeted beta-galactosidase gene was percutaneously delivered to the iliac artery of normal (n = 25) and atherosclerotic (n = 25) rabbits. Transgene expression, assessed by morphometric as well as chemiluminescent analyses, was documented in all normal and atherosclerotic arteries between 3 and 14 d after gene transfer, but was undetectable at later time points. Transfected cells were identified as smooth muscle cells located in the media of normal arteries, and in the neointima and the vasa-vasora of atherosclerotic arteries. Two percent of medial cells, but only 0.2% of medial and neointimal cells expressed the transgene in normal and atherosclerotic arteries, respectively (P = 0.0001). Similarly, nuclear beta-galactosidase activity was higher in normal than in atherosclerotic arteries (3.2 vs. 0.8 mU/mg protein, P = 0.02). These findings indicate that atherosclerosis reduces the transfection efficiency which can be achieved with adenoviral vectors, and thus constitutes a potential limitation to adenovirus-based, arterial gene therapy.

[Treatment of intrastent restenosis by drug eluting stents: experience from one cardiology centre]. / Traitement des resténoses intrastent par un stent actif: experience monocentrique.

Many interventional treatments have been proposed for intrastent stenosis, in particular by drug-eluting stents, with encouraging results. The aim of this study was to assess the clinical outcome of patients with restenosis of an ordinary uncovered stent treated by a drug eluting stent in a prospective series. The register included 43 patients (50 intrastent restenoses) treated by a drug eluting stent (Cypher or Taxus). The restenosis lesion was focal in 32% of cases with an average length of 14.8 +/- 8 mm and diameter inferior to 2.5 mm in 48% of cases. A Cypher stent was implanted in 44% of cases and a Taxus stent in 56% of cases. After an average follow-up of 6.7 +/- 1.3 months, the major adverse cardiac event rate was 9.3%. It included one transmural infarct in a patient, due to stent thrombosis, and symptomatic restenoses in 3 patients (clinical restenosis rate: 7%). An angiographic control was performed in 15 patients (35%) identifying focal restenosis at the exit of the stent in the 3 symptomatic patients. As in previously reported studies, these results show that with well conducted platelet antiaggregant therapy, the treatment of intrastent restenosis with a drug eluting stent is effective with a low rate of adverse cardiovascular events which compares favourably with previously proposed techniques of management.

Are there good and bad responders to prehospital thrombolysis in the acute phase of myocardial infarction? OPTIMAL study rationale.

The effectiveness of thrombolytics has been clearly demonstrated in more than half the cases in the large cohorts of patients selected for trials during the acute phase of myocardial infarction. At individual level, thrombolysis will clinically either succeed or fail so, for the medical team managing the patient, choice of treatment may be likened to a gamble which in the best of cases (most often) leads to an uncomplicated success and, in the worst of cases, failure worsened by a severe complication. OPTIMAL is a multidisciplinary and multicentre, prospective cohort study associating mobile medical teams and interventional cardiology units to test the hypothesis that the outcome of prehospital thrombolysis does not depend on chance alone but also varies according to demographic, etiological, clinical and logistic factors involved in the occurrence and management of myocardial infarction. The primary objective of this French study, conducted over one year on more than 800 subjects, is to identify the predictors of the results of prehospital thrombolysis from a very early angiographic evaluation. The results for this cohort may be useful for setting up appropriate management strategies for acute myocardial infarction, from the prehospital phase (thrombolysis or not) up to in-hospital orientation of the patients (angiography room or Intensive Care Unit) and to determine the most judicious time for coronary angiography. OPTIMAL is to date the largest prospective serie of prehospital thrombolysis evaluated by an early angiographic control.

Elevated levels of shed membrane microparticles with procoagulant potential in the peripheral circulating blood of patients with acute coronary syndromes.

BACKGROUND: Apoptotic microparticles are responsible for almost all tissue factor activity of the plaque lipid core. We hypothesized that elevated levels of procoagulant microparticles could also circulate in the peripheral blood of patients with recent clinical signs of plaque disruption and thrombosis. METHODS AND RESULTS: We studied 39 patients with coronary heart disease, including 12 patients with stable angina and 27 patients with acute coronary syndromes (ACS), and 12 patients with noncoronary heart disease. We isolated the circulating microparticles by capture with annexin V and determined their procoagulant potential with a prothrombinase assay. The cell origins of microparticles were determined in an additional 22 patients by antigenic capture with specific antibodies. The level of procoagulant microparticles did not differ between stable angina patients and noncoronary patients (10.1+/-1.6 nmol/L phosphatidylserine [PS] equivalent versus 9.9+/-1.6 nmol/L PS equivalent, respectively). However, procoagulant microparticles were significantly elevated in patients with ACS (22.2+/-2.7 nmol/L PS equivalent) compared with other coronary (P<0.01) or noncoronary (P<0.01) patients. Microparticles of endothelial origin were significantly elevated in patients with ACS (P<0.01), which suggests an important role for endothelial injury in inducing the procoagulant potential. CONCLUSIONS: High levels of procoagulant endothelial microparticles are present in the circulating blood of patients with ACS and may contribute to the generation and perpetuation of intracoronary thrombi.

Differential expression of matrix metalloproteinases after stent implantation and balloon angioplasty in the hypercholesterolemic rabbit.

BACKGROUND: Intimal hyperplasia is the principal mechanism of in-stent restenosis. Matrix metalloproteinases (MMPs) play a key role in intimal growth after balloon angioplasty (BA). Little is known, however, about MMP expression after stent implantation (ST). We investigated whether MMP9 and MMP2 are differentially expressed after ST and BA. METHODS AND RESULTS: Hypercholesterolemic rabbits underwent ST and BA in the right and left iliac arteries, respectively. The expression of MMPs and their inhibitors (TIMPs) was studied at various time points in the injured arteries by use of zymography, reverse transcription-polymerase chain reaction, and immunohistochemistry. MMP2, but not MMP9, was constitutively expressed in uninjured arteries. MMP9 expression was rapidly induced after injury, whereas the increase in MMP2 expression was delayed. At all time points, pro-MMP9 activity and MMP9 mRNA levels were >/=2-fold (ANOVA, P=0.002) and >/=3-fold (P<0.0001) higher after ST than after BA, respectively. Active MMP9 was detected only after ST. Although the increases in MMP2 mRNA levels were of similar magnitudes after ST and BA, pro-MMP2 activity was slightly higher 7 and 30 days after ST, and MMP2 activity was >/=2-fold higher 7 to 60 days after ST (P=0.002). No difference in TIMP expression was observed between stented and balloon-injured arteries. Cellular distributions of MMPs and TIMP1 were similar after ST and BA. Early inflammatory cell recruitment and 30-day intimal growth were more severe after ST. CONCLUSIONS: Stent implantation results in more intense and sustained expression of MMP9 and activation of MMP2 than balloon angioplasty.

Interleukin-10 inhibits intimal hyperplasia after angioplasty or stent implantation in hypercholesterolemic rabbits.

BACKGROUND: Intimal hyperplasia after stent implantation is the main cause of in-stent restenosis. Activated monocytes play a key role in intimal growth. The anti-inflammatory cytokine interleukin-10 (IL-10) is a potent monocyte deactivator, endogenously produced in the atherosclerotic plaque. We tested the hypothesis that exogenous IL-10 may limit postangioplasty intimal hyperplasia after balloon angioplasty or stenting. METHODS AND RESULTS: Hypercholesterolemic rabbits were treated with recombinant human IL-10 (rhuIL-10) for 3 days after balloon angioplasty or 28 days after stent implantation. High IL-10 serum levels and intense deactivation of circulating monocytic cells, assessed by inhibition of IL-1beta release by lipopolysaccharide-stimulated whole blood, were detected for at least 8 hours after rhuIL-10 intravenous injection (ELISA). Morphometric analyses, performed 28 days after injury, indicated that rhuIL-10 reduced intimal growth by approximately 50% after balloon angioplasty or stenting, resulting in more preserved lumen in stented arteries. Moreover, rhuIL-10 reduced macrophage infiltration by 67% and proliferative activity by 81% in the intima and the media. No toxic effect was detected except minor changes in blood cell count. CONCLUSIONS: The anti-inflammatory cytokine rhuIL-10 reduces postinjury intimal hyperplasia. The potent attenuation of in-stent intimal growth by rhuIL-10 and its favorable toxicity profile suggest that rhuIL-10 may be useful in the prevention of in-stent restenosis.