Treatment With Ezetimibe Plus Low-Dose Atorvastatin Compared With Higher-Dose Atorvastatin Alone

Safety and Effectiveness of High-Intensity Statins Versus Low/Moderate-Intensity Statins Plus Ezetimibe in Patients With Atherosclerotic Cardiovascular Disease for Reaching LDL-C Goals: A Systematic Review and Meta-Analysis

BACKGROUND

It remains controversial whether adding ezetimibe to low/moderate-intensity statins has a more beneficial impact on the treatment efficacy and safety of patients with existing atherosclerotic cardiovascular disease (ASCVD) compared to high-intensity statin regimens.

HYPOTHESIS

A combination of low/moderate-intensity statins plus ezetimibe might be more effective and safer than high-intensity statin monotherapy.

METHODS

We searched databases for randomized controlled trials comparing lipid profile alterations, drug-related adverse events, and MACE components between high-intensity statin monotherapy and low/moderate-intensity statin plus ezetimibe combination therapy. Pooled risk ratios (RR), mean differences (MD), and 95% confidence intervals (95% CI) were estimated using a random-effects model.

RESULTS

Our comprehensive search resulted in 32 studies comprising 6162 patients treated with monotherapy against 5880 patients on combination therapy. Combination therapy was more effective in reducing low-density lipoprotein cholesterol (LDL-C) levels compared to monotherapy (MD = -6.6, 95% CI: -10.6 to -2.5); however, no significant differences were observed in other lipid parameters. Furthermore, the combination therapy group experienced a lower risk of myalgia (RR = 0.27, 95% CI: 0.13-0.57) and discontinuation due to adverse events (RR = 0.61, 95% CI: 0.51-0.74). The occurrence of MACE was similar between the two treatment groups.

CONCLUSIONS

Adding ezetimibe to low/moderate-intensity statins resulted in a greater reduction in LDL-C levels, a lower rate of myalgia, and less drug discontinuation compared to high-intensity statin monotherapy in patients with existing cardiovascular disease. However, according to our meta-analysis, the observed reduction in LDL-C levels in the combination group did not correlate with a reduction in MACE compared to the high-intensity statin group.

Comparative Safety and Efficacy of Low/Moderate-Intensity Statin plus Ezetimibe Combination Therapy vs. High-Intensity Statin Monotherapy in Patients with Atherosclerotic Cardiovascular Disease: An Updated Meta-Analysis

AIM

Statin therapy is considered the gold standard for treating hypercholesterolemia. This updated meta-analysis aims to compare the efficacy and safety of a low/moderate-intensity statin in combination with ezetimibe compared with high-intensity statin monotherapy in patients with atherosclerotic cardiovascular disease (ASCVD).

METHODS

A systematic search of two databases (PubMed and Cochrane CENTRAL) was conducted from inception to January 2023 and a total of 21 randomized clinical trials (RCTs) were identified and included in the analysis. Data were pooled using Hedges's g and a Mantel-Haenszel random-effects model to derive standard mean differences (SMDs) and 95% confidence intervals (Cis). The primary outcome studied was the effect of these treatments on lipid parameters and safety events.

RESULTS

The results revealed that combination therapy was more effective in reducing low-density lipoprotein cholesterol (LDL-C) levels (SMD= - 0.41; CI - 0.63 to - 0.19; P = 0.0002). There was no significant change in the levels of high-density lipoprotein cholesterol (HDL-C), total cholesterol (TC), triglyceride (TG), high-sensitivity C-reactive protein (hs-CRP), Apo A1, or Apo B. The safety of these treatments was assessed by the following markers alanine aminotransferase (ALT), aspartate aminotransferase (AST), and creatine phosphokinase (CK), and a significant difference was only observed in CK (SMD: - 0.81; CI - 1.52 to - 0.10; P = 0.02).

CONCLUSION

This meta-analysis demonstrated that the use of low/moderate-intensity statin combination therapy significantly reduced LDL-C levels compared with high-intensity statin monotherapy, making it preferable for patients with related risks. However, further trials are encouraged to evaluate potential adverse effects associated with combined therapy.

Atorvastatin-mediated inhibition of prenylation of Rab27b and Rap1a in platelets attenuates their prothrombotic capacity and modulates clot structure

Statins inhibit the mevalonate pathway by impairing protein prenylation via depletion of lipid geranylgeranyl diphosphate (GGPP). Rab27b and Rap1a are small GTPase proteins involved in dense granule secretion, platelet activation, and regulation. We analyzed the impact of statins on prenylation of Rab27b and Rap1a in platelets and the downstream effects on fibrin clot properties. Whole blood thromboelastography revealed that atorvastatin (ATV) delayed clot formation time (P < .005) and attenuated clot firmness (P < .005). ATV pre-treatment inhibited platelet aggregation and clot retraction. Binding of fibrinogen and P-selectin exposure on stimulated platelets was significantly lower following pre-treatment with ATV (P < .05). Confocal microscopy revealed that ATV significantly altered the structure of platelet-rich plasma clots, consistent with the reduced fibrinogen binding. ATV enhanced lysis of Chandler model thrombi 1.4-fold versus control (P < .05). Western blotting revealed that ATV induced a dose-dependent accumulation of unprenylated Rab27b and Rap1a in the platelet membrane. ATV dose-dependently inhibited ADP release from activated platelets. Exogenous GGPP rescued the prenylation of Rab27b and Rap1a, and partially restored the ADP release defect, suggesting these changes arise from reduced prenylation of Rab27b. These data demonstrate that statins attenuate platelet aggregation, degranulation, and binding of fibrinogen thereby having a significant impact on clot contraction and structure.

Effect of High-Intensity Rosuvastatin vs. Combination of Low-Intensity Rosuvastatin and Ezetimibe on HbA1c Levels in Patients without Diabetes: A Randomized IDEAL Trial

There is a dearth of studies investigating whether the combination of low-intensity statins with ezetimibe can reduce the risk of diabetes in patients requiring statin therapy. Therefore, we aimed to evaluate the effects of combination therapy on the prevention of glycated hemoglobin (HbA1c) elevation in patients without diabetes. Sixty-eight patients were randomly assigned in a 1:1 ratio to receive a combination of low-intensity rosuvastatin (5 mg/day) and ezetimibe (10 mg/day) or high-intensity rosuvastatin (20 mg/day). The primary endpoint was the absolute difference in the HbA1c levels at 12 weeks. The HbA1c level showed an overall elevation of 0.11% at 12 weeks compared to that at baseline (mean ± standard deviation: 5.78 ± 0.3%, 95% confidence interval [CI]: 5.86-6.07, p = 0.044). The HbA1c levels did not differ between the groups at 12 weeks (least square mean difference: 0.001, 95% CI: 0.164-0.16, p = 0.999). Our study found that the combination of low-intensity rosuvastatin and ezetimibe did not yield significant differences in HbA1c levels compared to high-intensity rosuvastatin alone after 12 weeks in patients without diabetes. This suggests that the combination of low-intensity rosuvastatin and ezetimibe may not be an effective strategy for preventing HbA1c elevation in patients without diabetes requiring statins.

Comparative safety and efficacy of low- or moderate-intensity statin plus ezetimibe combination therapy and high-intensity statin monotherapy: A meta-analysis of randomized controlled studies

Statin is highly recommended for dyslipidemia to prevent atherosclerosis-related cardiovascular diseases and death. The aim of this study was to compare the efficacies and safeties of low/moderate-intensity statin plus ezetimibe combination therapy vs. high-intensity statin monotherapy. Meta-analysis was conducted on data included in published studies performed to compare the effects of the two treatments on lipid parameters and hs-CRP. Safety-related parameters were also evaluated. Eighteen articles were included in the meta-analysis. In terms of efficacy, low/moderate-intensity statin plus ezetimibe reduced LDL-C (SE = 0.307; 95% CI 0.153–0.463), TC (SE = 0.217; 95% CI 0.098–0.337), triglyceride (SE = 0.307; 95% CI 0.153–0.463), and hs-CRP (SE = 0.190; 95% CI 0.018–0.362) significantly more than high-intensity statin therapy. In terms of safety, the two treatments were not significantly different in terms of ALT elevation, but high-intensity statin increased AST and CK significantly more than combination therapy. This analysis indicates that low/moderate-intensity statin plus ezetimibe combined therapy is more effective and safer than high-intensity statin monotherapy, which suggests the addition of ezetimibe to statin should be preferred over increasing statin dose and that high-intensity statin should be used more carefully, especially in patients with related risks.

Pleiotropic Effects of PCSK9: Focus on Thrombosis and Haemostasis

The proprotein convertase subtilisin/keying 9 (PCSK9) is a serine protease that has gained importance in recent years as a drug target, mainly due to its effect on cholesterol metabolism in promoting the degradation of the low-density lipoprotein receptor (LDLR). However, this protease may also play an important role in lipid-independent reactions, including the process of thrombogenesis. Considering this, we reviewed the effects and implications of PCSK9 on platelet function and blood coagulation. PCSK9 knockout mice exhibited reduced platelet activity and developed less agonist-induced arterial thrombi compared to the respective control animals. This is in line with known research that elevated blood levels of PCSK9 are associated with an increased platelet reactivity and total number of circulating platelets in humans. Moreover, PCSK9 also has an effect on crucial factors of the coagulation cascade, such as increasing factor VIII plasma levels, since the degradation of this blood clotting factor is promoted by the LDLR. The aforementioned pleiotropic effects of the PCSK9 are important to take into account when evaluating the clinical benefit of PCSK9 inhibitors.

Interaction of Lipids, Mean Platelet Volume, and the Severity of Coronary Artery Disease Among Chinese Adults: A Mediation Analysis

Objective

Currently, coronary artery disease (CAD) is regarded as one of the leading global disease burdens. Evidence proved that platelet activation in dyslipidemia induced CAD, however, their interaction has not been well-established in vivo. This study aims to assess the mediation effects of mean platelet volume (MPV) in lipids and the severity of CAD.

Methods

We prospectively enrolled 5,188 consecutive subjects who underwent coronary angiography between 2015 and 2020. Participants were grouped according to their CAD events, which was defined as stenosis ≥50% in at least one coronary artery, and whose severity was evaluated by the Gensini score (GS). A lipid index was drawn by principal component analysis to weight related lipid parameters including total cholesterol (TC), low density lipoprotein cholesterol (LDL-C), high density lipoprotein cholesterol (HDL-C), non-HDL-C, apolipoprotein (apo) A1 B. The interaction of lipids and MPV in atherosclerosis was evaluated by the mediation analysis.

Results

Lipid index increased with elevated GS irrespective of statin status (not on statin: β = 0.100, p < 0.001; on statin: β = 0.082, p < 0.001). Multiple linear regression indicated positive correlation between MPV and GS after adjustment (β = 0.171, p < 0.001). Subjects in the highest MPV tertile had higher levels of atherogenic lipid parameters and lipid index (p < 0.001). The adjusted odds ratios were greater among individuals undergoing statin medications who had high GS and higher MPV levels by elevated lipid index tertiles [1.168 (0.893–1.528) vs. 2.068 (1.552–2.756) vs. 1.764 (1.219–2.551)]. The combination of lipid index and MPV provided better prediction for high GS than individual lipid index or MPV, as shown by receiver-operating characteristic (ROC) curves (areas under ROC curves were 0.700 and 0.673 in subjects on or not on statin treatment, respectively). Significantly, mediation analysis revealed the mediation interaction of lipid index on GS by MPV, whose effect size reached 20.71 and 20.07% in participants with or without statin medications.

Conclusion

The increased risk of dyslipidemia on CAD was partly enhanced by elevated MPV levels, whose mediating effect was around 20%.

Simvastatin-induced Changes in the Leukocytic System of Porcine Bone Marrow

Introduction

Simvastatin is a substance which is commonly used as a medicine to reduce cholesterol level. Unfortunately, it shows numerous side effects. Simvastatin affects various internal organs, and among other detriments to health may cause persistent muscle weakness, osteolytic processes, headaches, and rashes. Until now knowledge of the influence of simvastatin on bone marrow cells has been rather scant and fragmentary.

Material and Methods

During this experiment the numbers of all types of cells in the leukocytic system of porcine bone marrow were evaluated after 28 and 56 days of oral administration of simvastatin at a dose of 40 mg/day/animal.

Results

Simvastatin caused an increase in the number of all types of cells in the leukocytic system, and the most visible fluctuations concerned promyelocytes.

Conclusion

Observations obtained during the present study indicated that the results of the action of simvastatin on porcine bone marrow differ from those observed in other mammal species, including human. This may be due to various metabolic pathways within the bone marrow in the particular species, but the exact mechanisms of these actions are unknown at the present time.

Design of the randomized, placebo-controlled evolocumab for early reduction of LDL-cholesterol levels in patients with acute coronary syndromes (EVOPACS) trial

Statins lower low-density lipoprotein cholesterol (LDL-C) and improve clinical outcomes in patients with atherosclerotic cardiovascular disease (CVD). Patients with acute coronary syndromes (ACS) often do not achieve LDL-C targets despite potent statin treatment, and have a particularly high risk of early recurrent events. Evolocumab, a proprotein convertase subtilisin/kexin type (PCSK9)-inhibitor resulting in rapid, marked LDL-C reduction, has been studied in hypercholesterolemic subjects without CVD and stabilized patients with CVD; the feasibility, safety, and efficacy of this treatment initiated in the acute phase of ACS remain unknown. We report the design of evolocumab for early reduction of LDL-cholesterol levels in patients with ACS (EVOPACS), a phase-3, multicenter, randomized, double-blind, placebo-controlled trial to assess the feasibility, safety, and LDL-C-lowering efficacy of evolocumab on top of atorvastatin 40 mg in patients with ACS. The primary endpoint is percent change in LDL-C from baseline to 8 weeks. Secondary endpoints are adverse events and serious adverse events. Against a background of beneficial cardiovascular effects of statins beyond LDL-C lowering and in view of preclinical evidence of similar effects of PCSK9 inhibition, the study will also address a variety of exploratory endpoints including the change in C-reactive protein and other inflammatory biomarkers; platelet reactivity; and occurrence of contrast-induced acute kidney injury and myocardial injury in patients undergoing cardiac catheterization. An intracoronary imaging sub-study will investigate the change from baseline in the lipid core burden index in non-culprit lesions, as assessed by serial near-infrared spectroscopy. Recruitment began in January 2018 and enrollment of 308 patients is planned.

Effects of statin therapy on platelet reactivity after percutaneous coronary revascularization in patients with acute coronary syndrome

Statin use is associated with enhanced pharmacodynamic response to clopidogrel in patients with stable coronary artery disease undergoing percutaneous coronary intervention (PCI). However, the impact of statin therapy on clopidogrel response profiles in patients with acute coronary syndrome (ACS) undergoing PCI has not been established and represents the objective of this investigation. On-treatment P2Y₁₂ platelet reactivity was measured using the vasodilator stimulated phosphoprotein (VASP) phosphorylation assay before PCI, at hospital discharge, and at 1 month after PCI in ACS patients enrolled in the multicenter, prospective GEne polymorphisms, Platelet Reactivity, and Syntax Score (GEPRESS) study (n = 962). High platelet reactivity (HPR) was defined as platelet reactivity index ≥50%. Statins were prescribed at hospital discharge in 87% (n = 835) of patients. All patients were followed for 1 year. The 1-month HPR rate was lower in statin than in non-statin treated patients (39.6 vs 52%, respectively, p = 0.009). This finding was confirmed also among statin-treated patients with high Syntax score (≥15). After adjustment for differences in baseline characteristics, statin use at discharge was independently associated with 1-month HPR rate (odds ratio, 0.58, 95% confidence interval, 0.38-0.89; p = 0.015). In ACS patients undergoing PCI treated with clopidogrel the use of statins at discharge was associated with significantly lower 1-month HPR rates compared with patients not treated with statins.

Therapeutic effects of atorvastatin and ezetimibe compared with double-dose atorvastatin in very elderly patients with acute coronary syndrome

Objective Compared the effect of atorvastatin 10 mg combined ezetimibe 10 mg therapy with atorvastatin 20 mg on the long-term outcomes in very elderly patients with acute coronary syndrome.

Methods A total of 230 octogenarian patients with acute coronary syndrome underwent coronary angiography were randomized to combined therapy group (atorvastatin 10 mg/d and ezetimibe 10 mg/d, n=114) or double-dose atorvastatin group (atorvastatin 20mg/d, n=116). The primary end point was one-year incidence of major adverse cardiovascular events (including cardiac death, spontaneous myocardial infarction, unplanned revascularization).

Result At the end of one year, the percentage of patients with low-density lipoprotein cholesterol level decreased more than 30% or 50% were comparable between the two groups (93.5% vs. 90.1%, p= 0.36; 54.6% vs. 49.6%, p= 0.45). The rate of major adverse cardiovascular events in combined therapy group was similar with double-dose atorvastatin group (23.2% vs. 19.8%, p=0.55). In COX regression model, the risk of major adverse cardiovascular events in combined group isn’t significantly higher than double-dose atorvastatin group (HR [95% CI] 1.12 [0.51 to 2.55], p = 0.74). The patients whose alanine aminotransferase increasing more than upper normal limit in combined group was lower than double-dose atorvastatin group (2.8% vs. 9.0%, p = 0.05).

Conclusions For very elderly patients with acute coronary syndrome, atorvastatin combining ezetimibe induced similar long-term outcomes compared with double-dose atorvastatin but with less liver dysfunction.

INNOVATION Study (Impact of Immediate Stent Implantation Versus Deferred Stent Implantation on Infarct Size and Microvascular Perfusion in Patients With ST-Segment-Elevation Myocardial Infarction)

BACKGROUND

The aim of this study was to assess whether deferred stenting (DS) reduces infarct size and microvascular obstruction (MVO) compared with immediate stenting (IS) in primary percutaneous coronary intervention for ST-segment-elevation myocardial infarction.

METHODS AND RESULTS

From February 2013 to August 2015, 114 patients (mean age: 69 years) were randomized into the following 2 groups: DS with an intention to stent 3 to 7 days later or IS after primary reperfusion in 2 centers. The primary and secondary end points were infarct size and the incidence of MVO, respectively, assessed by cardiac magnetic resonance imaging at 30 days after primary reperfusion. The median time to the second procedure in the DS was 72.8 hours. Six patients in the DS group were crossed over to the IS group because of progression of dissection or safety concerns after randomization. In the intention-to-treat analysis, DS did not significantly reduce infarct size (15.0% versus 19.4%; P=0.112) and the incidence of MVO (42.6% versus 57.4%; P=0.196), compared with IS. However, in anterior wall myocardial infarction, infarct size (16.1% versus 22.7%; P=0.017) and the incidence of MVO (43.8% versus 70.3%; P=0.047) were significantly reduced in the DS group. There was no urgent revascularization event during deferral period.

CONCLUSIONS

A routine DS did not significantly reduce infarct size and MVO compared with IS, although it was safe. The beneficial effect of DS in patients with anterior myocardial infarction should be confirmed by larger randomized studies.

CLINICAL TRIAL REGISTRATION

URL: http://www.clinicaltrials.gov. Unique identifier: NCT02324348.

High-intensity Statin Treatments in Clinically Stable Patients on Aspirin Monotherapy 12 Months After Drug-eluting Stent Implantation: A Randomized Study

INTRODUCTION AND OBJECTIVES

Current guidelines on the treatment of blood cholesterol recommend continuous maintenance of high-intensity statin treatment in drug-eluting stent (DES)-treated patients. However, high-intensity statin treatment is frequently underused in clinical practice after stabilization of DES-treated patients. Currently, the impact of continuous high-intensity statin treatment on the incidence of late adverse events in these patients is unknown. We investigated whether high-intensity statin treatment reduces late adverse events in clinically stable patients on aspirin monotherapy 12 months after DES implantation.

METHODS

Clinically stable patients who underwent DES implantation 12 months previously and received aspirin monotherapy were randomly assigned to receive either high-intensity (40mg atorvastatin, n = 1000) or low-intensity (20mg pravastatin, n = 1000) statin treatment. The primary endpoint was adverse clinical events at 12-month follow-up (a composite of all death, myocardial infarction, revascularization, stent thrombosis, stroke, renal deterioration, intervention for peripheral artery disease, and admission for cardiac events).

RESULTS

The primary endpoint at 12-month follow-up occurred in 25 patients (2.5%) receiving high-intensity statin treatment and in 40 patients (4.1%) receiving low-intensity statin treatment (HR, 0.58; 95%CI, 0.36-0.92; P = .018). This difference was mainly driven by a lower rate of cardiac death (0 vs 0.4%, P = .025) and nontarget vessel myocardial infarction (0.1 vs 0.7%, P = .033) in the high-intensity statin treatment group.

CONCLUSIONS

Among clinically stable DES-treated patients on aspirin monotherapy, high-intensity statin treatment significantly reduced late adverse events compared with low-intensity statin treatment.

CLINICAL TRIAL REGISTRATION

URL: http://www.clinicaltrials.gov. Unique identifier: NCT01557075.

Platelet reactivity in response to loading dose of atorvastatin or rosuvastatin in patients with stable coronary disease before percutaneous coronary intervention: The STATIPLAT randomized study

BACKGROUND

The acute effects of statin loading dose (LD) on platelet reactivity in patients with chronic stable angina (CSA) are not completely clear.

HYPOTHESIS

We hypothesized that LDs of atorvastatin and rosuvastatin have different pharmacodynamic acute effects on platelet aggregability in CSA patients with baseline normal platelet reactivity while on dual antiplatelet therapy (DAPT).

METHODS

From September 2011 to February 2014, all consecutive CSA patients on chronic DAPT (aspirin and clopidogrel) were evaluated before elective percutaneous coronary intervention (PCI). An initial assessment of platelet reactivity in response to thrombin receptor agonist, ADP, and ASP (respectively, indicative of the response to clopidogrel and aspirin) was performed with impedance aggregometry. Patients with high platelet reactivity to ADP test (area under the curve >47) were excluded. The remaining patients were randomized into 3 treatment groups: Group A, atorvastatin LD 80 mg; Group B, rosuvastatin LD 40 mg; and Group C, no statin LD (control group). A second assessment of platelet reactivity was performed ≥12 hours after statin LD.

RESULTS

682 patients were screened and 145 were randomized into the 3 groups. At baseline and after statin LD, no significant difference was found in platelet reactivity in response to 3 different agonists between the 3 groups. Subgroup analysis showed that platelet reactivity to ADP test was significantly lower in patients chronically treated with low-dose statins (n = 94) compared with statin-naïve patients (n = 51; 15.32 ± 1.50 vs 18.59 ± 1.30; P = 0.007).

CONCLUSIONS

Loading dose of atorvastatin (80 mg) or rosuvastatin (40 mg) did not induce significant variation in platelet reactivity in CSA patients with baseline reduced platelet reactivity as in chronic DAPT. Our data confirm that chronic concomitant treatment with low-dose statins and clopidogrel resulted in significantly lower platelet reactivity compared with clopidogrel alone.

Atorvastatin Decreased Circulating RANTES Levels in Impaired Glucose Tolerance Patients with Hypercholesterolemia: An Interventional Study

INTRODUCTION

Impaired glucose tolerance (IGT) is the major cause of the development of both type 2 diabetes and atherosclerosis. Regulated upon activation, normal T cells expressed and secreted (RANTES), a proinflammatory chemokine, is associated with atherosclerosis. We investigated the effect of atorvastatin on circulating RANTES in IGT patients with hypercholesterolemia.

METHODS

This study evaluated cross-sectional and interventional studies of 32 IGT patients with hypercholesterolemia (group A) and 32 controls (group B). Group A was treated with atorvastatin (20 mg/day) for 8 weeks. Platelet-free plasma (PFP) RANTES and clinical characteristics were examined.

RESULTS

PFP RANTES was significantly higher in group A compared with group B (9.76 ± 3.10 vs 6.43 ± 2.16 ng/ml, P < 0.001). PFP RANTES was positively correlated with total cholesterol (TC) (r = 0.589, P < 0.001), low-density lipoprotein cholesterol (LDL-C) (r = 0.583, P < 0.001), triglycerides (TG) (r = 0.450, P < 0.001), fasting blood glucose (FBG) (r = 0.469, P < 0.001), 2-hour postchallenge glucose (2hPG) (r = 0.397, P = 0.001), glycosylated hemoglobin (HbA1c) (r = 0.353, P = 0.004), and high sensitivity C-reactive protein (hsCRP) (r = 0.616, P < 0.001), and negatively related to high-density lipoprotein cholesterol (HDL-C) (r = -0.272, P = 0.029). After controlling for confounders, LDL-C (β = 2.109, P < 0.001) and hsCRP (β = 0.272, P = 0.029) were independently related to RANTES. After atorvastatin treatment, PFP RANTES significantly decreased in group A compared with baseline (from 9.76 ± 3.10 to 7.48 ± 2.78 ng/ml, P < 0.001).

CONCLUSIONS

Atorvastatin decreased circulating RANTES in IGT patients with hypercholesterolemia, indicating that statins may play an important role in inhibiting inflammatory responses in patients with IGT.

Intensive atorvastatin improves endothelial function and decreases ADP-induced platelet aggregation in patients with STEMI undergoing primary PCI: A single-center randomized controlled trial

BACKGROUND

Intensive atorvastatin may be beneficial for patients with ST segment elevated myocardial infarction (STEMI). However, its effects on endothelial and residual platelet function remain uninvestigated in these patients.

METHODS

This single-center single-blinded prospective randomized controlled trial included STEMI patients undergoing PCI, aiming to investigate the acute effects of intensive atorvastatin (40mg) vs. standard atorvastatin (20mg) on serum endothelin-1 (ET-1) and ADP-induced platelet clot strength (MA-ADP), which were measured before and after 7days of atorvastatin treatment respectively. MA-ADP was measured by thromboelastography. The tolerance and safety of intensive atorvastatin therapy in these patients were also observed.

RESULTS

A total of 120 patients (60 patients in the intensive group and 60 patients in the standard group) with STEMI, who are undergoing primary PCI, were included into this study (mean age, 63.5years). Patients from these two groups were matched for baseline characteristics. Atorvastatin did not significantly affect the serum level of LDL-C or CRP in either the standard or intensive group. Furthermore, ET-1 did not significantly change following treatment with atorvastatin in the standard group. However, intensive treatment with atorvastatin significantly reduced ET-1 serum level (0.65±0.38pmol/L vs. 0.49±0.21pmol/L, P<0.05) and achieved a greater reduction of MA-ADP (49.2±12.1 vs. 38.4±17.4mm, P<0.05). In addition, although not statistically significant, patients assigned to the intensive group appeared to suffer from less major adverse cardiovascular events.

CONCLUSIONS

Periprocedural intensive atorvastatin is associated with improved endothelial function and platelet inhibition, and is well-tolerated in STEMI patients undergoing PCI.

Inhibition of platelet function with clopidogrel is associated with a reduction of inflammation in patients with peripheral artery disease

BACKGROUND

The reactivity of platelets is increased in patients with peripheral artery disease (PAD). RANTES and sCD40L are chemokines which are stored in the alpha-granules of platelets. Clopidogrel inhibits and thus reduces platelet reactivity. Whether a treatment with clopidogrel is associated with an inhibition of systemic inflammation in patients with PAD has not been thoroughly explored. This study examined the effect of clopidogrel on platelet reactivation and the release of inflammatory chemokines in patients with PAD.

METHODS

40 patients with PAD were randomized into two groups. In the first group A the patients were treated with 100mg acetylsalicylic acid (ASA) and additional placebo for 4weeks. The patients in group B received 75mg/d clopidogrel in addition to ASA 100mg for 4weeks. After obtaining blood at days 0, 7 and 28 the platelet activation was determined by measuring the surface protein expression of CD63, CD62p and thrombospondin (TSP) after stimulation with TRAP and ADP. The release of the chemokines RANTES and sCD40L from platelets was analyzed by ELISA.

RESULTS

Platelet activation markers (CD62p and CD63) and chemokine RANTES were significantly reduced in patients with PAD after 7 and 28days after treatment with clopidogrel. No alterations were found in TSP expression and sCD40L during the treatment.

CONCLUSION

The treatment with clopidogrel leads to a reduction of platelet reactivity and release of RANTES from the platelets of patients with PAD.

Measurement of microparticle tissue factor activity in clinical samples: A summary of two tissue factor-dependent FXa generation assays

Thrombosis is a leading cause of morbidity and mortality. Detection of a prothrombotic state using biomarkers would be of great benefit to identify patients at risk of thrombosis that would benefit from thromboprophylaxis. Tissue factor (TF) is a highly procoagulant protein that under normal conditions is not present in the blood. However, increased levels of TF in the blood in the form of microparticles (MPs) (also called extracellular vesicles) are observed under various pathological conditions. In this review, we will discuss studies that have measured MP-TF activity in a variety of diseases using two similar FXa generation assay. One of the most robust signals for MP-TF activity (16-26 fold higher than healthy controls) is observed in pancreatic cancer patients with venous thromboembolism. In this case, the TF+ MPs appear to be derived from the cancer cells. Surprisingly, cirrhosis and acute liver injury are associated with 17-fold and 38-fold increases in MP-TF activity, respectively. Based on mouse models, we speculate that the TF+ MPs are derived from hepatocytes. More modest increases are observed in patients with urinary tract infections (6-fold) and in a human endotoxemia model (9-fold) where monocytes are the likely source of the TF+ MPs. Finally, there is no increase in MP-TF activity in the majority of cardiovascular disease patients. These studies indicate that MP-TF activity may be a useful biomarker to identify patients with particular diseases that have an increased risk of thrombosis.

Effect of High-Dose Statin Therapy on Drug-Eluting Stent Strut Coverage

Objective—

The influence of high-dose statin therapy on the serial stent healing process has not been fully investigated. Using optical coherence tomography, the effect of high-dose statin therapy on stent strut coverage was evaluated in drug-eluting stent–treated patients.

Approach and Results—

Sixty patients were randomly assigned to 2 groups according to the statin dose (atorvastatin 40 mg as high-dose statin therapy [n=29] versus pravastatin 20 mg as low-dose statin therapy [n=31]). Serial optical coherence tomographic evaluation post procedure and at the 3-month and 12-month follow-ups was performed in 50 patients with 54 stents (23 atorvastatin-treated patients versus 27 pravastatin-treated patients). The percentage of uncovered struts was defined as the ratio of uncovered struts/total struts. The primary end point was the percentage of uncovered struts at the 12-month follow-up. The secondary end point was the percentage of uncovered struts at the 3-month follow-up and the comparative percentage change (Δ) of uncovered struts at the 3- and 12-month follow-ups between the different dose statin therapies. The percentage of uncovered struts was 7.4% (range, 4.3%–10.4%) in atorvastatin-treated patients versus 10.6% (range, 5.7%–22.6%) in pravastatin-treated patients at the 3-month follow-up ( P =0.13) and 1.3% (0.3%–3.8%) versus 2.5% (0.9%–9.7%), respectively, at the 12-month follow-up ( P =0.01). The percentage Δ of uncovered struts from 3 to 12 months of follow-up was −7.9±8.5% in atorvastatin-treated patients versus −9.3±12.5% in pravastatin-treated patients ( P =0.67).

Conclusions—

This study suggested that high-dose statin therapy might provide a beneficial effect for the vascular healing process after drug-eluting stent implantation.

Elevated RANTES level is associated with metabolic syndrome and correlated with activated platelets associated markers in healthy younger men

The objective of this study was to clarify the relationship of regulated on activation normal T cell expressed and secreted (RANTES) levels with metabolic syndrome (MS) and activated platelets-associated markers. We conducted a cross-sectional study of 210 healthy Japanese male volunteers (mean age 41 years old) who did not take any medications and were free of cardiovascular or cerebrovascular disease. The RANTES is correlated with age, diastolic blood pressure, and fast glucose by multivariate analysis using the cardiovascular risk factors (R (2) = .396, P < .001). The plasma RANTES level is significantly associated with MS after adjusting for age (P = .040). Once plasma interleukin 6, an activator of platelets, and plasma platelet-derived microparticles, a marker for activated platelets, are put into the equation, plasma RANTES level is significantly correlated with the activated platelet-associated markers (R (2) = .396, P < .001). These suggest the possible role of elevated RANTES in the forerunner of atherosclerosis in healthy younger men.

Statins in the prevention of contrast-induced nephropathy

OPINION STATEMENT

Coronary angiography and percutaneous coronary interventions are common procedures that utilize iodinated contrast medium to visualize the coronary arterial tree and treat stable and unstable ischemic heart syndromes. Exposure to contrast agents can cause acute and persistent worsening of renal function leading to increased morbidity and mortality. Certain patient characteristics such as age, presence of diabetes, congestive heart failure, chronic kidney disease, hemodynamic instability on presentation, and type and volume of contrast used can increase the risk of developing contrast-induced nephropathy (CIN) and its subsequent complications. Despite the lack of a universal definition, CIN is typically defined as an increase in serum creatinine ≥0.5 mg/dL or 25 % above baseline 48 to 72 h after contrast exposure. Previous research has shown the benefits of adequate intravenous hydration with iso-osmolar crystalloids and the importance of limiting the amount of low-osmolar and iso-osmolar contrast used to prevent the development of CIN. 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitors (statins) have anti-inflammatory and anti-apoptotic properties with few side effects, making it an attractive therapeutic option for prevention of CIN. A number of trials have examined the benefit of different types of statins, high-dose versus low-dose statins, loading versus chronic dosing of statins, in various clinical presentations including acute coronary syndromes and elective procedures, and in those with associated comorbidities such as anemia and chronic kidney disease. In this review, we will summarize recent data regarding statin therapy for prevention of contrast-induced nephropathy.

The influence of statin therapy on platelet activity markers in hyperlipidemic patients after ischemic stroke

INTRODUCTION

Low-density lipoprotein cholesterol (LDL-C) has been reported to increase platelet activation. Reducing the level of LDL-C with statins induces important pleiotropic effects such as platelet inhibition. This association between platelet activity and statin therapy may be clinically important in reducing the risk of ischemic stroke. We investigated the effect of simvastatin therapy on platelet activation markers (platelet CD62P, sP-selectin, and platelet-derived microparticles (PDMPs)) in hyperlipidemic patients after ischemic stroke.

MATERIAL AND METHODS

The study group consisted of 21 hyperlipidemic patients after ischemic stroke confirmed by CT, and 20 healthy subjects served as controls. We assessed the CD62P expression on resting and thrombin-activated blood platelets. CD62P and PDMPs were analyzed by the use of monoclonal antibodies anti-CD61 and anti-CD62 on a flow cytometer. The level of sP-selectin in serum was measured by the ELISA (enzyme-linked immunosorbent assay) method. All markers were re-analyzed after 6 months of treatment with simvastatin (20 mg/day).

RESULTS

Hyperlipidemic patients presented a significantly higher percentage of CD62+ platelets and higher reactivity to thrombin compared to control subjects. After simvastatin therapy hyperlipidemic patients showed a reduction of the percentage of resting CD62P(+) platelets (p = 0.005) and a reduction of expression and percentage of CD62P(+) platelets after activation by thrombin (median p < 0.05; percentage: p = 0.001). A decrease of sP-selectin levels (p = 0.001) and percentage of PDMPs (p < 0.05) in this group was also observed.

CONCLUSIONS

HMG-CoA reductase inhibitor therapy in stroke patients with hyperlipidemia may be useful not only due to the lipid-lowering effect but also because of a significant role in reduction of platelet activation and reactivity.

The effect of clopidogrel on platelet activity in patients with and without type-2 diabetes mellitus: a comparative study

Background

Although antiplatelet therapy involving clopidogrel is a standard treatment for preventing cardiovascular events after coronary stent implantation, patients can display differential responses. Here, we assessed the effectiveness of clopidogrel on platelet function inhibition in subjects with and without type-2 diabetes and stable coronary artery disease. In addition, we investigated the correlation between platelet function and routine clinical parameters.

Methods

A total of 64 patients with stable coronary heart disease were enrolled in the study. Among these, 32 had known type-2 diabetes, whereas the remaining 32 subjects were non-diabetics (control group). A loading dose of 300 mg clopidogrel was given to clopidogrel-naïve patients (13 patients in the diabetes group and 14 control patients). All patients were given a daily maintenance dose of 75 mg clopidogrel. In addition, all patients received 100 mg ASA per day. Agonist-induced platelet aggregation measurements were performed on hirudin-anticoagulated blood using an impedance aggregometer (Multiple Platelet Function Analyzer, Dynabyte, Munich, Germany). Blood samples were drawn from the antecubital vein 24 h after coronary angiography with percutaneous coronary intervention. The platelets were then stimulated with ADP alone or ADP and prostaglandin-E (ADP and ADP-PGE tests, respectively) in order to evaluate clopidogrel-mediated inhibition of platelet function. The effectiveness of ASA was measured by stimulation with arachidonic acid (ASPI test). In addition, maximal platelet aggregation was assessed via stimulation with thrombin receptor-activating peptide (TRAP test).

Results

Patients with diabetes exhibited significantly less inhibition of platelet function than patients without diabetes (ADP-PGE test p = 0.003; ASPI test p = 0.022). Administering a clopidogrel loading dose of 300 mg did not result in a lower level of ADP-PGE-induced platelet reactivity in comparison to the use of a 75 mg maintenance dose. Moreover, we observed that ADP-PGE-induced platelet inhibition was positively correlated with fasting blood glucose and HbA1c (p < 0.01).

Conclusions

Patients with type-2 diabetes exhibited increased platelet reactivity compared to patients without diabetes despite combined treatment with clopidogrel and ASA. Using a loading dose of clopidogrel rather than small daily doses was not sufficient for adequately overcoming increased platelet reactivity in patients with type-2 diabetes, highlighting the need for more effective anti-platelet drugs for such patients.

Early high-dose rosuvastatin and cardioprotection in the protective effect of rosuvastatin and antiplatelet therapy on contrast-induced acute kidney injury and myocardial damage in patients with acute coronary syndrome (PRATO-ACS) study

BACKGROUND

There is a strong correlation between adverse clinical events and peak values of myocardial necrosis markers in non-ST-elevation acute coronary syndrome patients. In this clinical setting, high-dose statin treatment exerts acute beneficial effects against renal and myocardial damage. The aim of this report was to evaluate if, on admission, high-dose rosuvastatin can exert cardioprotective effects when administered in addition to high-dose clopidogrel.

METHODS

In the PRATO-ACS trial, 504 consecutive statin-naïve non-ST-elevation acute coronary syndrome patients scheduled for early invasive strategy and pretreated with high-dose clopidogrel were randomly assigned to rosuvastatin (40 mg on admission followed by 20 mg/d; statin group, n = 252) or no statin treatment (control group, n = 252). Serial myocardial biomarker samples were collected before and after angiography and/or percutaneous coronary intervention. The primary end point was the peak level of cardiac troponin I (cTnI) during the index event.

RESULTS

Statin-treated patients presented median cTnI peak values similar to controls (3.9 [0.6-12.8] vs 3.5 [1.2-11.9] ng/mL, respectively; P = .60]; no differences were found between the 2 groups in cTnI and creatine kinase-MB values at any time point, in either preangiography and postangiography peak values or their cumulative release. In patients submitted to percutaneous coronary intervention, periprocedural myocardial infarction occurred in 8 (4.7%) of 171 statin-treated and 7 (4.3%) of 162 control patients (P = .87).

CONCLUSION

In the PRATO-ACS trial, early high-dose rosuvastatin did not show cardioprotective effects when administered in addition to high-dose clopidogrel.

Influence of previous statin therapy on cholesterol-lowering effect of ezetimibe

BACKGROUND AND OBJECTIVES

The inhibition of cholesterol absorption by ezetimibe increases cholesterol synthesis. The effect of inhibition of cholesterol synthesis on cholesterol absorption is controversial. The influence of these interactions on cholesterol levels is unknown. We investigated on the extent to which cholesterol levels were affected by the reaction of one pathway to the inhibition of the other pathway.

SUBJECTS AND METHODS

This case-controlled study enrolled 198 patients who needed cholesterol-lowering drugs. Ezetimibe (10 mg) was administered to the patients with (n=58) and without on-going statin therapy (n=58). Simvastatin (20 mg) was administered to the patients treated with (n=41) and without ezetimibe (n=41).

RESULTS

Ezetimibe without statin lowered the total cholesterol by 13.3±8.8% (p<0.001) and the low density lipoprotein-cholesterol (LDL-C) by 18.7±15.3% (p<0.001). Ezetimibe added to statin decreased the total cholesterol by 21.1±7.7% (p<0.001) and the LDL-C by 29.9±12.6% (p<0.001). The total cholesterol and LDL-C were reduced more by ezetimibe in patients with statin therapy than in those without statin therapy (p<0.001 and p<0.001, respectively). The differences in the effect of simvastatin on total cholesterol and LDL-C between the patients with and without ezetimibe showed borderline significance (p=0.10 and p=0.055, respectively).

CONCLUSION

A prior inhibition of cholesterol synthesis by statin enhanced the effect of ezetimibe on total cholesterol and LDL-C by 7.8% and 11.2%, respectively. This finding suggests that ezetimibe increased cholesterol synthesis, resulting in a significant elevation of cholesterol levels.

High-potency statin and ezetimibe use and mortality in survivors of an acute myocardial infarction: a population-based study

OBJECTIVE

To determine all-cause mortality in patients with a first myocardial infarct who were treated with simvastatin compared with high-potency statin and simvastatin/ezetimibe combination.

BACKGROUND

Despite statin use, residual cardiovascular risk remains. Therapeutic options include more potent statins or addition of ezetimibe. There is no clinical outcome data on the use of ezetimibe in such patients.

METHODS

Retrospective longitudinal study using the United Kingdom General Practice Research Database. Patients who had survived 30 days after their first acute myocardial infarct (AMI), had not received prior statin or ezetimibe therapy and were started on a statin within 30 days of AMI were included. Three groups were identified according to their follow-up: (i) simvastatin monotherapy; (ii) high-potency statin group (patients who started on simvastatin and switched to atorvastatin or rosuvastatin); and (iii) ezetimibe/statin combination group (patients who received ezetimibe in addition to statin).

RESULTS

9597 patients (57% male, mean age of 65 ± 13 years) matched study criteria: simvastatin (n=6990 (72.8%)); high-potency statin (n=1883, (19.6%)); and ezetimibe/statin combination (n=724 (7.5%)). During a mean follow-up of 3.2 years, there were 1134 (12%) deaths. In the multivariate proportional hazards model, the adjusted HR for high-potency statin and ezetimibe group were 0.72 (95% CI 0.59 to 0.88, p<0.001) and 0.96 (95% CI 0.64 to 1.43, p=0.85), respectively. A similar result was also obtained in the propensity score analysis that took into account covariates that predicted drug treatment groups.

CONCLUSIONS

Patients switched to a high-potency statin had a significantly reduced mortality compared with simvastatin monotherapy. There was no observed mortality benefit in the ezetimibe group.

Effect of statins on platelet function in patients with hyperlipidemia

INTRODUCTION

It is generally assumed that cholesterol reduction by statins is the predominant therapeutic result underlying their beneficial effects in cardiovascular disease. However, the action of statins may be partially independent of their effects on plasma cholesterol levels, as they combine lipid lowering with positive effects on hemorheological conditions and endothelial function. We evaluated the impact of statin treatment on platelet adhesion to fibrinogen (spontaneous and ADP-activated), along with ADP, collagen or ristocetin-induced aggregation in type II hyperlipidemic patients.

MATERIAL AND METHODS

The study group included 70 persons: 50 patients affected by type II hyperlipidemia without concomitant diseases and 20 healthy volunteers. The effects of 8-week statin treatment (atorvastatin 10 mg/day, simvastatin 20 mg/day, or pravastatin 20 mg/day) on platelet activation were evaluated.

RESULTS

Regardless of the type of statin, a significant decrease in ADP-induced platelet aggregation was observed: for atorvastatin 50.6 ±12.8% vs. 41.1 ±15.8% (p < 0.05), for simvastatin 57.2 ±18.0% vs. 44.7 ±22.1% (p = 0.05), and for pravastatin 55.8 ±19.5% vs. 38.8 ±23.3% (p < 0.05). There was no significant effect of statins on collagen or ristocetin-induced platelet aggregation and adhesion.

CONCLUSIONS

Therapy with statins beneficially modifies ADP-induced platelet aggregation in patients with hyperlipidemia and does not affect spontaneous or ADP-induced platelet adhesion to fibrinogen and platelet aggregation induced by collagen or ristocetin.

High-dose atorvastatin on the pharmacodynamic effects of double-dose clopidogrel in patients undergoing percutaneous coronary interventions: The ACHIDO (Atorvastatin and Clopidogrel HIgh DOse in stable patients with residual high platelet activity) study

OBJECTIVES

The goal of this study was to investigate the impact of high-dose atorvastatin on the pharmacodynamic (PD) effects of double-dose clopidogrel in statin-naive patients with stable coronary artery disease (CAD) and high-on-treatment platelet reactivity (HTPR) while on standard-dose clopidogrel before percutaneous coronary intervention (PCI).

BACKGROUND

Patients with HTPR are at increased risk of adverse cardiovascular events after PCI. High-dose statins improve prognosis in high-risk patients by lipid- and nonlipid-related mechanisms, including antithrombotic effects.

METHODS

The ACHIDO (Atorvastatin and Clopidogrel HIgh DOse in stable patients with residual high platelet activity) study was a randomized PD study of high-dose (80 mg) atorvastatin in addition to double-dose (150 mg) clopidogrel (atorvastatin group, n = 38) versus double-dose clopidogrel alone (control group, n = 38) in patients with HTPR. HTPR was defined as P2Y(12) reaction units (PRU) ≥235 by the VerifyNow P2Y12 assay. Platelet reactivity was evaluated immediately before PCI and at 10 and 30 days.

RESULTS

Patients randomized to atorvastatin had lower PRU values (188 ± 48 vs. 223 ± 53 PRU, p < 0.01; primary endpoint) and HTPR rates (16% vs. 42%, p < 0.01) at 30 days than patients in the control group. Statin treatment (odds ratio [OR]: 3.8, p = 0.011), baseline PRU <298 (OR: 10.7, p = 0.0001), noncarrier status of CYP2C19*2 loss-of-function allele (OR: 2.9, p = 0.043), and age (OR: 0.94, p = 0.032) were variables significantly associated with optimal PD response (PRU <235) at 30 days. No correlations were found between PRU and lipid fractions.

CONCLUSIONS

High-dose atorvastatin significantly improved the PD effects of double-dose clopidogrel in our stable CAD patients with HTPR undergoing PCI (Atorvastatin and Clopidogrel HIgh DOse in stable patients with residual high platelet activity [ACHIDO]; NCT01335048).

Comparison of anti-inflammatory effects and high-density lipoprotein cholesterol levels between therapy with quadruple-dose rosuvastatin and rosuvastatin combined with ezetimibe

BACKGROUND

Statins are frequently administered to reduce low-density lipoprotein cholesterol (LDL-C) and vascular inflammation, because LDL-C and high sensitive C-reactive protein (hs-CRP) are associated with high risk for cardiovascular events. When statins do not reduce LDL-C to desired levels in high-risk patients with coronary artery disease (CAD), ezetimibe can be added or the statin dose can be increased. However, which strategy is more effective for treating patients with CAD has not been established. The present study compares anti-inflammatory effects and lipid profiles in patients with CAD and similar LDL-C levels who were treated by increasing the statin dose or by adding ezetimibe to the original rosuvastatin dose to determine the optimal treatment for such patients.

METHODS

46 patients with high-risk CAD and LDL-C and hs-CRP levels of >70 mg/dL and >1.0 mg/L, respectively, that were not improved by 4 weeks of rosuvastatin (2.5 mg/day) were randomly assigned to receive 10 mg (R10, n = 24) of rosuvastatin or 2.5 mg/day of rosuvastatin combined with 10 mg/day of ezetimibe (R2.5/E10, n = 22) for 12 weeks. The primary endpoint was a change in hs-CRP.

RESULTS

Baseline characteristics did not significantly differ between the groups. At 12 weeks, LDL-C and inflammatory markers (hs-CRP, interleukin-6, tumour necrosis factor-alpha and pentraxin 3) also did not significantly differ between the two groups (LDL-C: R10 vs. R2.5/E10: -19.4 ± 14.2 vs. -22.4 ± 14.3 mg/dL). However, high-density lipoprotein cholesterol (HDL-C) was significantly improved in the R10, compared with R2.5/E10 group (4.6 ± 5.9 vs. 0.0 ± 6.7 mg/dL; p < 0.05).

CONCLUSION

Both enhanced therapies exerted similar anti-inflammatory effects under an equal LDL-C reduction in patients with high-risk CAD despite 2.5 mg/day of rosuvastatin. However, R10 elevated HDL-C more effectively than R2.5/E10.

TRIAL REGISTRATION

UMIN000003746.

Atorvastatin delays murine platelet activation in vivo even in the absence of endothelial NO synthase

OBJECTIVE

Statins decrease mortality in patients with vascular disorders, and evidence for the pleiotropic effects of statins is accumulating. Statins enhance endothelial NO synthase (eNOS) expression, thereby attenuating platelet activation and thrombus formation. Our goal was to determine whether statins have eNOS-independent effects on platelet activation.

METHODS AND RESULTS

Wild-type and eNOS-deficient mice were given a 14-day course of oral atorvastatin, and platelet activation was evaluated in vitro and in vivo. Whereas in wild-type mice atorvastatin inhibited platelet activation in vitro in response to numerous agonists, in eNOS-deficient mice, atorvastatin inhibited only thrombin-induced and protease-activated receptor 4 agonist peptide-induced platelet activation. Consistent with an eNOS-independent effect, atorvastatin inhibited platelet activation in vivo in both wild-type and eNOS-deficient mice.

CONCLUSIONS

Atorvastatin inhibits platelet activation via eNOS-dependent and eNOS-independent mechanisms with the latter restricted to protease-activated receptor 4-induced activation downstream to the receptor.

Doubling the clopidogrel dose in patients with reduced responsiveness to the standard dose is associated with a limited effectiveness as evaluated by impedance aggregometry

BACKGROUND

Different methods are available for quantifying platelet function inhibition. Measuring vasodilator-stimulated phosphoprotein (VASP) phosphorylation is currently the most specific method for assessing the clopidogrel effect. The aim of our study was to compare different tests in view of a clinically applicable bedside test. Further, we examined whether doubling the clopidogrel dose to 150mg/d in clopidogrel low-responder would lead to a reduction in platelet reactivity.

METHODS AND RESULTS

ADP-, ADP Hs-, and TRAP-induced platelet aggregation were measured by impedance aggregometry in 100 patients with CAD and 18 healthy controls. Moreover, platelet aggregation was assessed by flow cytometrical detection of VASP-phosphorylation and surface P-selectin in a subgroup of 34 patients and in healthy controls. Another 10 patients with CAD, identified as low-responder, were treated with a clopidogrel dose of 150mg/d. Thereafter, ADP-induced platelet aggregation was assessed by impedance aggregometry. Significant correlations were observed between ADP-induced platelet aggregation assessed by VASP-phosphorylation and by impedance aggregometry. Doubling the dose of clopidogrel to 150mg/d was associated with a reduction of ADP-induced platelet aggregation in only 60% of the patients.

CONCLUSIONS

Impedance aggregometry is a valuable bedside test to assess platelet function inhibition. Doubling the clopidogrel dose is not effective to reduce high on-treatment platelet reactivity in almost half of these patients, pointing to the need of a more powerful platelet inhibitor.

Efficacy of short-term high-dose statin in preventing contrast-induced nephropathy: a meta-analysis of seven randomized controlled trials

Background

A few studies focused on statin therapy as specific prophylactic measures of contrast-induced nephropathy have been published with conflicting results. In this meta-analysis of randomized controlled trials, we aimed to assess the effectiveness of shor-term high-dose statin treatment for the prevention of CIN and clinical outcomes and re-evaluate of the potential benefits of statin therapy.

Methods

We searched PubMed, OVID, EMBASE, Web of science and the Cochrane Central Register of Controlled Trials databases for randomized controlled trials comparing short-term high-dose statin treatment versus low-dose statin treatment or placebo for preventing CIN. Our outcome measures were the risk of CIN within 2–5 days after contrast administration and need for dialysis.

Results

Seven randomized controlled trials with a total of 1,399 patients were identified and analyzed. The overall results based on fixed-effect model showed that the use of short-term high-dose statin treatment was associated with a significant reduction in risk of CIN (RR = 0.51, 95% CI 0.34–0.76, p = 0.001; I² = 0%). The incidence of acute renal failure requiring dialysis was not significant different after the use of statin (RR = 0.33, 95% CI 0.05–2.10, p = 0.24; I² = 0%). The use of statin was not associated with a significant decrease in the plasma C-reactive protein level (SMD −0.64, 95% CI: −1.57 to 0.29, P = 0.18, I² = 97%).

Conclusions

Although this meta-analysis supports the use of statin to reduce the incidence of CIN, it must be considered in the context of variable patient demographics. Only a limited recommendation can be made in favour of the use of statin based on current data. Considering the limitations of included studies, a large, well designed trial that incorporates the evaluation of clinically relevant outcomes in participants with different underlying risks of CIN is required to more adequately assess the role for statin in CIN prevention.

Bivalirudin inhibits periprocedural platelet function and tissue factor expression of human smooth muscle cells

AIM

A major concern of stent implantation after percutaneous coronary intervention (PCI) is acute stent thrombosis. Effective inhibition of periprocedural platelet function in patients with coronary artery disease (CAD) leads to an improved outcome. In this study, we examined the periprocedural platelet reactivity after administrating bivalirudin during PCI compared to unfractionated heparin (UFH) administration. Further, the effect of bivalirudin on induced tissue factor (TF) expression in smooth muscle cells (SMC) was determined.

METHODS

Patients with CAD (n = 58) and double antithrombotic medication were treated intraprocedural with UFH (n = 30) or bivalirudin (n = 28). Platelet activation markers were flow cytometrically measured before and after stenting. The expression of TF in SMC was determined by real-time PCR and Western blotting. The thrombogenicity of platelet-derived microparticles and SMC was assessed via a TF activity assay.

RESULTS

Bivalirudin significantly diminished the agonist-induced platelet reactivity post-PCI. Compared to UFH treatment, the adenosine diphosphate (ADP) and thrombin receptor-activating peptide (TRAP)-induced thrombospondin expression post-PCI was reduced when bivalirudin was administrated during intervention. In contrast to UFH, bivalirudin reduced the P-selectin expression of unstimulated and ADP-induced platelets post-PCI. Moreover, bivalirudin inhibited the thrombin-, but not FVIIa- or FVIIa/FX-induced TF expression and pro-coagulant TF activity of SMC. Moreover, bivalirudin reduced the TF activity of platelet-derived microparticles postinduction with TRAP or ADP.

CONCLUSIONS

Bivalirudin is better than UFH in reducing periprocedural platelet activation. Moreover, thrombin-induced TF expression is inhibited by bivalirudin. Thus, bivalirudin seems to be a better anticoagulant during PCI than UFH.

The effects of statin monotherapy and low-dose statin/ezetimibe on lipoprotein-associated phospholipase A₂

BACKGROUND

Many of the pleiotropic effects of statins remain to be elucidated.

HYPOTHESIS

Different statin regimens with similar lipid-lowering efficacy may have different effects on biomarkers of atherothrombosis including lipoprotein-associated phospholipase A₂ (Lp-PLA₂ ).

METHODS

After a 4-week dietary lead-in, 82 hypercholesterolemic patients were randomized to 1 of 2 treatment groups: atorvastatin 20 mg or atorvastatin/ezetimibe 5 mg/5 mg. After 8 weeks of drug treatment, the groups were compared for percent change in lipid parameters, Lp-PLA₂ , interleukin-6 (IL-6), monocyte chemoattractant protein-1, and fibrinogen.

RESULTS

Low-density lipoprotein cholesterol (LDL-C) lowering was comparable between the 2 groups (-47% ± 11% and -49% ± 7% in the atorvastatin and combination groups, respectively). Although Lp-PLA₂ was reduced in both groups, the reduction was greater in the atorvastatin group (-42% and -9% [median], respectively, P = 0.03). Although IL-6 was decreased only in the atorvastatin group, IL-6 changes were not significantly different between the 2 groups. The changes in monocyte chemoattractant protein-1 and fibrinogen were similar in each group.

CONCLUSIONS

Atorvastatin monotherapy was stronger at reducing plasma Lp-PLA₂ than the low-dose atorvastatin/ezetimibe combination after equivalent LDL-C lowering. This result may provide evidence of potential statin effects beyond the lowering of LDL-C.

Effects of ezetimibe added to ongoing statin therapy on C-reactive protein levels in hypercholesterolemic patients

BACKGROUND AND OBJECTIVES

Ezetimibe alone does not decrease C-reactive protein (CRP) levels in hypercholesterolemic patients. However, several reports have suggested that ezetimibe might potentiate the effect of statin not only on cholesterol but also on CRP when administered together. We investigated the effect of ezetimibe on CRP levels in patients taking statins.

SUBJECTS AND METHODS

Patients who had not achieved recommended low density lipoprotein-cholesterol (LDL-C) goals with statin therapy were divided into two groups, the ezetimibe group (n=60) and the control group (n=60). A third group of hypercholesterolemic patients without statin therapy was treated with statin (n=59). Patients with CRP level 10 mg/L were excluded. Lipid and CRP levels were measured before therapy commenced, and after 2 months of therapy.

RESULTS

Ezetimibe decreased cholesterol and LDL-C levels by 20.2% (p=0.000) and 28.1% (p=0.000) respectively. However, ezetimibe did not reduce CRP levels (from 0.83±0.68 to 1.14±1.21 mg/dL, p=0.11). CRP levels remained unchanged in the control group (p=0.42). In contrast, statin lowered CRP levels (from 0.82±0.73 to 0.65±0.57 mg/dL, p=0.008). In patients taking statins, changes in CRP levels were not associated with changes in LDL-C (r=-0.02, p=0.87), but with baseline CRP levels (r=-0.38, p=0.000).

CONCLUSION

Ezetimibe failed to reduce CRP levels in hypercholesterolemic patients taking statins despite significant reduction of LDL-C. This finding suggests that the anti-inflammatory effect of statin may not be secondary to cholesterol reduction, but via other mechanisms.

Pleiotropic effects of ezetimibe/simvastatin vs. high dose simvastatin

BACKGROUND

In the setting of stable coronary artery disease (CAD), it is not known if the pleiotropic effects of cholesterol reduction differ between combined ezetimibe/simvastatin and high-dose simvastatin alone.

OBJECTIVE

We sought to compare the anti-inflammatory and antiplatelet effects of ezetimibe 10mg/simvastatin 20mg (E10/S20) with simvastatin 80 mg (S80).

METHODS AND RESULTS

CAD patients (n=83, 63 ± 9 years, 57% men) receiving S20, were randomly allocated to receive E10/S20 or S80, for 6 weeks. Lipids, inflammatory markers (C-reactive protein, interleukin-6, monocyte chemoattractant protein-1, soluble CD40 ligand and oxidized LDL), and platelet aggregation (platelet function analyzer [PFA]-100) changes were determined. Baseline lipids, inflammatory markers and PFA-100 were similar between groups. After treatment, E10/S20 and S80 patients presented, respectively: (1) similar reduction in LDL-C (29 ± 13% vs. 28 ± 30%, p=0.46), apo-B (18 ± 17% vs. 22 ± 15%, p=0.22) and oxidized LDL (15 ± 33% vs. 18 ± 47%, p=0.30); (2) no changes in inflammatory markers; and, (3) a higher increase of the PFA-100 with E10/S20 than with S80 (27 ± 43% vs. 8 ± 33%, p=0.02).

CONCLUSIONS

These data suggest that among stable CAD patients treated with S20, (1) both E10/S20 and S80 were equally effective in further reducing LDL-C; (2) neither treatment had any further significant anti-inflammatory effects; and (3) E10/S20 was more effective than S80 in inhibiting platelet aggregation. Thus, despite similar lipid lowering and doses 4× less of simvastatin, E10/S20 induced a greater platelet inhibitory effect than S80.

Effect of different loading doses of atorvastatin on percutaneous coronary intervention for acute coronary syndromes

BACKGROUND

Percutaneous coronary intervention (PCI)-induced myocardial damage is associated with late cardiovascular events. Treatment with atorvastatin before PCI can reduce myocardial damage during the peri-PCI period.

OBJECTIVES

To compare the safety and myocardial effects of different atorvastatin loading doses and dosing frequency before PCI in non-ST segment elevation acute coronary syndrome (NSTE-ACS) patients.

METHODS

Eighty NSTE-ACS patients were randomly divided into four groups (20 patients per group). The control group was given 40 mg atorvastatin each night. The three loading dose groups were treated the same as in the control group, but were given 80 mg atorvastatin 12 h before PCI (lowload group) in combination with 40 mg atorvastatin 2 h to 4 h before PCI (mid-load group) or 60 mg atorvastatin 2 h to 4 h before PCI (high-load group). All patients underwent PCI within 48 h to 72 h of admission, and received 40 mg atorvastatin for at least one month after PCI. Changes in myocardial markers and highly sensitive C-reactive protein were analyzed. Patients were followed up for 30 days to monitor the incidence of major adverse cardiac events (MACE).

RESULTS

No deaths or revascularizations were recorded. The incidences of MACE differed significantly between the four groups (40%, 25%, 10% and 0% for the control, low-load, mid-load and high-load groups, respectively; P<0.05). The incidence of MACE and cardiac troponin I level above the normal range, and post-PCI increases in creatine kinase-MB and highly sensitive C-reactive protein were significantly higher in the control group than in the high-load group (all P<0.007). The post-PCI alanine aminotransferase levels in all four groups were significantly higher than the pre-PCI levels, but were within normal ranges. No myalgia or myasthenia was observed.

CONCLUSION

The results of the present study show that short-term atorvastatin loading before PCI was well tolerated and had beneficial myocardial effects in patients with NSTE-ACS.