Statins have an early antiplatelet effect in patients with acute myocardial infarction

HMG-CoA reductase inhibitors and the attenuation of risk for disseminated intravascular coagulation in patients with sepsis

BACKGROUND

Disseminated Intravascular Coagulation (DIC) is a syndrome of dysregulated coagulation. Patients with sepsis are at increased risk for DIC. HMG-CoA Reductase Inhibitors (Statins) are primarily used as lipid-lowering agents; however, studies have suggested statins may possess anti-inflammatory, antithrombotic, anticoagulant, and endothelial stabilizing properties. These mechanisms may oppose those that underlie the pathogenesis of septic DIC.

METHODS

To evaluate whether statins may be protective against the development of DIC, we conducted a multi-center, retrospective case-control study where 86,638 critically ill patients admitted to the ICU with sepsis, severe sepsis or septic shock were identified during a 3-year period. Patients who developed DIC during their hospitalization were identified and stratified by whether they received a statin or not during their hospitalization. Odds ratios for development of DIC was calculated by composite of any statin, as well as low, moderate, and high intensity statins.

RESULTS

2236 patients would develop DIC compared to 84,402 who did not. The use of any statin was associated with a reduced likelihood for developing DIC (odds ratio [OR], 0.69; 95% CI, 0.61-0.78). This was observed with use of both moderate (OR, 0.64; 95% CI, 0.53-0.77) and high (OR, 0.72; 95% CI, 0.61-0.84) but not low intensity statins (OR, 0.84; 95% CI, 0.53-1.32).

CONCLUSIONS

The use of moderate and high intensity statins was associated with a significantly reduced odds of developing DIC in critically ill patients with sepsis. This present study may be the first to suggest that statin medications may independently reduce the frequency of DIC in critically ill patients with severe sepsis or septic shock. More research is needed to investigate the potential for this class of medication to be protective against DIC.

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%.

Statin use and mortality in atrial fibrillation: A systematic review and meta-analysis of 100,287 patients

Statins are effective for reducing cardiovascular disease in patients at risk or with cardiovascular disease. The benefit of statin therapy on adverse cardiovascular outcomes in patients with non-valvular atrial fibrillation (AF) is not clear. We performed a systematic review and meta-analysis of studies retrieved from MEDLINE via PubMed and Cochrane (CENTRAL) database of studies investigating the efficacy of statins in AF patients. The principal endpoint was all-cause mortality. Other endpoints were cardiovascular mortality, ischemic stroke, composite endpoints and any bleeding. We included 14 studies (2 post-hoc analysis of randomized clinical trials, 8 prospective and 4 retrospective) with 100,287 AF patients, of whom 23,228 were on statins. The pooled hazard ratio (HR) for all-cause mortality was 0.59 (95 % Confidence Interval [CI] 0.54-0.65). This association was consistent by aging, sex and prevalent cardiovascular or cerebrovascular disease. and the beneficial effect was evident already after 12 months of therapy. The absolute risk reduction for all-cause mortality in patients treated with statins was 10 % (95 % CI 9-10). The pooled HR for statins against cardiovascular mortality was 0.75 (95 % CI 0.58-0.96). No association was found with other secondary endpoints. Regarding bleeding events, the pooled HR for statin use was 0.60 (95 % CI 0.48-0.76). Our meta-analysis shows that in AF patients, statin therapy was associated with a reduction in all-cause and cardiovascular mortality are reduced by 41 % and 25 %, respectively. Randomized clinical trials in AF patients are necessary, as well as clarity on AF-specific LDL cholesterol targets.

Statin rosuvastatin inhibits apoptosis of human coronary artery endothelial cells through upregulation of the JAK2/STAT3 signaling pathway

The purpose of the present study was to explore the potential molecular signaling pathway mediated by the statin rosuvastatin in cultured human coronary artery endothelial cells (HCAECs) induced by CoCl2. CoCl2 was used to induce the apoptosis of HCAECs. Myocardial infarction rats were established and received statin or PBS treatment. Reverse transcription‑quantitative PCR, western blotting, ELISA, TUNEL assay and immunohistochemistry were used to analyze the role of statin treatment. The results showed that rosuvastatin treatment decreased apoptosis of HCAECs induced by CoCl2 by increasing anti‑apoptosis Bcl‑xl and Bcl‑2 expression, and decreasing pro‑apoptosis Bax, Bad, caspase‑3 and caspase‑9 expression. The myocardial ischemia rat model demonstrated that rosuvastatin treatment decreased the mitochondrial reactive oxygen species, inflammation, mitochondrial damage, lipid catabolism, heart failure and the myocardial infarction areas, but improved the cardiac function indicators, right and left ventricular ejection fraction and increased expression levels of Janus kinase (JAK) and signal transducer and activator of transcription (STAT)3 in myocardial tissue. In conclusion, the results of the current study revealed that the statin rosuvastatin presents cardioprotective effects by activation of the JAK2/STAT3 signaling pathway.

Statins significantly reduce mortality in patients receiving clopidogrel without affecting platelet activation and aggregation: a systematic review and meta-analysis

BACKGROUND

Combination of statins and clopidogrel is frequently administered in patients with coronary artery disease (CAD). They are mainly activated and eliminated in the liver by cytochrome P450 isoenzyme 3A4 (CYP3A4). The aim was to clarify whether the coadministration of clopidogrel and statins attenuate respective efficacy.

METHODS

PubMed, Embase, the Cochrane Library, Web of Science and Clinical Trials. gov were searched for until August 2018. Randomized controlled trials (RCTs) and cohort studies were taken into quality evaluation. Data were pooled using random effect models to estimate standard mean difference (SMD) or risk ratio (RR) with 95% confidence interval (CI).

RESULTS

In total, 28 studies representing 25,267 participants were included. Statins reduce the mortality of patients administered clopidogrel (RR 0.54; 95% CI 0.40,0.74; p = 0.000), no differences were found in platelet aggregation (PA) (SMD 0.02; 95% CI -0.38,0.42; p = 0.920) and the expressions of P-selectin (SMD -0.04; 95% CI -0.14,0.05; p = 0.346), CD40L (SMD 0.09; 95% CI -0.29,0.48; p = 0.633), CD63 (SMD 0.09; 95% CI -0.01,0.19; p = 0.079) and PAC-1 (SMD 0.03; 95% CI -0.08,0.13; p = 0.633). Furthermore, CYP3A4 metabolized or non-CYP3A4 metabolized statins have no discrepancies in PA (SMD 0.13; 95% CI -0.31,0.58; p = 0.556), P-selectin (SMD 0.17; 95% CI -0.16,0.51; p = 0310), death (RR 0.89; 95% CI 0.38,2.07; p = 0.791), except for triglyceride (TG) (SMD -0.19; 95% CI -0.33,-0.06; p = 0.005).

CONCLUSIONS

This meta-analysis confirmed that statins reduce mortality in patients undergoing clopidogrel treatment without affecting platelet activation and aggregation.

Dyslipidemia induced inflammatory status, platelet activation and endothelial dysfunction in rabbits: Protective role of 10-Dehydrogingerdione

10-Dehydrogingerdione is a novel cholesteryl ester transfer protein (CETP) inhibitor of natural origin. Some synthetic CETP inhibitors have recently been reported to suppress proprotein convertase subtilisin/kexin type 9 (PCSK9). Therefore, the present study aimed mainly to clarify the effect of 10-Dehydrogingerdione on cellular adhesion inflammatory molecules, platelet activation and endothelial dysfunction markers in addition to PCSK9 as compared to atorvastatin in dyslipidemic rabbits. Dyslipidemia was induced in 30 male rabbits, distributed in 3 equal groups through feeding dietary cholesterol (0.5% w/w) for 3 months. Two dyslipidemic groups were concurrently treated with either atorvastatin or 10-Dehydrogingerdione (10 mg/kg/ day, p.o) and dietary cholesterol. One additional group including 10 normal rabbits fed normal diet served as normal control (NC) group. Both 10-Dehydrogingerdione and atorvastatin significantly reduced serum CETP level and activity as well as PCSK9 and low density lipoprotein cholesterol (LDL-C) levels but increased high density lipoprotein cholesterol (HDL-C) levels as compared to dyslipidemic control (DC) rabbits (p <  0.001). Both treatments also induced a marked decrease in the interferon-gamma (IFN-γ), soluble CD40 ligand (sCD40L) and soluble P-selectin (sP-selectin) levels, inflammatory cell infiltration, as well as atherogenic and coronary risk indexes in addition to aortic atheromatous changes and intima/media ratio, respectively as compared to the DC group (p <  0.001). The reduction in these markers showed a significant correlation with PCSK9 suppression and CETP inhibitory effect. Interestingly, 10-Dehydrogingerdione exerted a greater ameliorative potential regarding these biomarkers than atorvastatin. Our findings suggest that 10-Dehydrogingerdione is a promising PCSK9 inhibitor with a significant protective value against many atherosclerotic risk factors.

Cardiovascular Risk Reduction: A Pharmacotherapeutic Update for Antiplatelet Medications

This update presents evidence for new antiplatelet therapies including modified P2Y₁₂ inhibitors and a new class of thromboxane antagonists. Discussed are emerging data on established antihyperlipidemic medications that support an additional antiplatelet effect. Current information about the effectiveness of several bleeding reversal agents is discussed, and the concept of personalized antiplatelet therapy, wherein selection of an antiplatelet therapy is based on genetic factors or laboratory testing that predict response to therapy and risk of adverse effects. Finally, future drug targets are introduced and drug interactions that can be leveraged to design more effective and safe antiplatelet therapies are described.

Simvastatin Effects on Inflammation and Platelet Activation Markers in Hypercholesterolemia

Background

Beside the lipid-lowering effect, statins slow the progression of atherosclerosis by exerting anti-inflammatory and platelet inhibiting effects. We investigated whether platelet inhibition by simvastatin correlates with the statin effects on lipid lowering, inflammation, oxidative stress, and endothelial and platelet activation.

Methods

In hypercholesterolemic patients allocated to diet (n=20) or a 2-month treatment with diet plus 40 mg simvastatin (n=25), we evaluated platelet aggregating responses to ADP, collagen, and arachidonic acid (AA), the effect of aspirin on AA-induced aggregation, pro- and anti-inflammatory and atherogenic mediators (IL-1β, -5, -6, -7, -8, -9, -10, -12, and -13, IFN-γ, IP-10, Eotaxin, and sRAGE), markers of endothelium (sE-selectin, VEGF, and MCP-1) and platelet activation (sP-selectin, sCD-40L, RANTES, and PDGF-bb), and oxidative stress (8-OH-2'-deoxyguanosine).

Results

After treatment, beside the improvement of lipid profile, we observed the following: a reduction of platelet aggregation to ADP (p=0.0001), collagen (p=0.0001), AA (p=0.003); an increased antiaggregating effect of aspirin in the presence of AA (p=0.0001); a reduction of circulating levels of IL-6 (p=0.0034), IL-13 (p<0.0001), IFN-γ (p<0.0001), VEGF (p<0.0001), sE-selectin (p<0.0001), sCD-40L (p<0.0001), sP-selectin (p=0.003), and 8-OH-2'-deoxyguanosine (p<0.0001); an increase of IL-10 and sRAGEs (p=0.0001 for both). LDL-cholesterol levels (i) positively correlated with IL-6, IFN-γ, E-selectin, sCD-40L, 8-OH-2'-deoxyguanosine, platelet aggregation to ADP, collagen, AA, and aspirin IC-50 and (ii) negatively correlated with IL-10 and sRAGE. In multiple regression analyses, LDL-cholesterol was the strongest predictor for most parameters of platelet reactivity.

Conclusion

In primary hypercholesterolemia, simvastatin treatment reduced platelet activation and subclinical inflammation and improved endothelial dysfunction. LDL-cholesterol levels were the major correlate of platelet reactivity; however, other effects of statins may contribute to reducing the progression of atherosclerosis.

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.

High-dose atorvastatin versus moderate dose on early vascular protection after ST-elevation myocardial infarction

Background and aim

Clinical benefits of early high-dose statin therapy after acute coronary syndromes are widely known; however, there is poor evidence on the specific setting of ST-elevation myocardial infarction (STEMI) and dose-dependent effects of this therapy on endothelial function and inflammatory biomarkers in the most vulnerable phase after acute coronary syndromes: the postdischarge period. In our study, we compared the short-term effects of high (80 mg) vs moderate doses of atorvastatin (20 mg) in patients with STEMI undergoing primary percutaneous coronary intervention on endothelial function and vascular inflammation. The aim of our study was the evaluation of dose-dependent short-term effects.

Subjects and methods

We enrolled 52 patients within 48 hours of a STEMI to atorvastatin 80 mg (n=26) or 20 mg (n=26). Every patient underwent endothelial function evaluation by the reactive hyperemia–peripheral arterial tonometry (RH-PAT) index on the first day and 1 month after the STEMI. At the same time, we measured lipid profile and serum levels of high-sensitivity CRP, IL6, TNFα, and oxidized LDL.

Results

After 1 month of therapy, we observed differences in high-sensitivity CRP levels (0.04±0.02 mg/dL vs 0.36±0.3 mg/dL, P=0.001), IL6 (1.12±0.93 pg/mL vs 3.13±2.84 pg/mL, P=0.03), and improvement in RH-PAT index (1.96±0.16 vs 1.72±0.19, P=0.002) in the group treated with high-dose vs moderate-dose atorvastatin. There was no significant difference in levels of TNFα or oxidized LDL with atorvastatin 20 mg, while there was a reduction in these variables in the group treated with atorvastatin 80 mg. We observed a correlation between high-sensitivity polymerase chain reaction and RH-PAT index on the 30th day after STEMI (r=0.5, P=0.001).

Conclusion

Higher dose statin therapy in patients with STEMI undergoing primary percutaneous coronary intervention showed early greater vascular protective effects that moderate dose.

Effects of atorvastatin on ADP-, arachidonic acid-, collagen-, and epinephrine-induced platelet aggregation

Objective

Atorvastatin reduces the incidence of cardiovascular events. However, the effects of atorvastatin on platelet aggregation are unknown.

Methods

Blood samples were obtained from 126 healthy volunteers. Prepared isolated platelet suspensions were adjusted with saline to three different concentrations of 100 × 10⁹, 300 × 10⁹, and 600 × 10⁹ platelets/L. Platelet samples were incubated with atorvastatin (10⁻⁷mol/L, 10⁻⁶mol/L or 10⁻⁵mol/L), and stimulated with ADP (10 µmol/L), arachidonic acid (0.5 mmol/L), collagen (2 µg/mL), and epinephrine (1 mg/mL). The maximal amplitude of aggregation and the curve slope were measured by electric impedance aggregometry.

Results

Atorvastatin inhibited platelet aggregation at moderate (300 × 10⁹/L) and high (600 × 10⁹/L) concentrations. However, an inhibitory effect of atorvastatin at low concentrations (100 × 10⁹/L) was not observed.

Conclusions

The study shows that atorvastatin inhibits platelet aggregation in vitro, and this inhibitory effect is related to platelet concentrations.

Myocardial Infarct Size in Patients on Long-Term Statin Therapy Undergoing Primary Percutaneous Coronary Intervention for ST-Elevation Myocardial Infarction

Statin pretreatment has been reported to have a cardioprotective effect in patients undergoing elective or urgent percutaneous coronary intervention (PCI). However, data on patients with ST-elevation myocardial infarction (STEMI) undergoing primary PCI are still controversial. We prospectively evaluated the effect of long-term statin therapy on infarct size (IS), myocardial salvage index (MSI), and microvascular obstruction (MVO) in consecutive patients with STEMI who underwent primary PCI. Two-hundred thirty patients with STEMI (mean age 61 ± 11 years, 183 men) who underwent primary PCI were evaluated with cardiac magnetic resonance (CMR) imaging during hospitalization (median 4 days after primary PCI). In all patients, we measured peak troponin I level, whereas IS, MSI, and MVO were determined by CMR. Fifty patients (22%) were on long-term statin therapy and showed a significantly lower troponin I peak value compared to patients without previous statins (54 ± 47 vs 88 ± 106 ng/ml; p = 0.02). At CMR evaluation, IS related to the index event was significantly smaller (12.5 ± 11.5 vs 18.5 ± 18.5 g, p = 0.05), and MSI was higher (0.68 ± 0.25 vs 0.52 ± 0.30; p <0.01) in patients with previous statin therapy. MVO was also less frequent (10% vs 20%; p = 0.14) in this group. At multivariate analysis, previous statin therapy remained significantly associated with IS and MSI (p = 0.05 and 0.02, respectively). In conclusion, this study suggests that long-term statin therapy before primary PCI in patients with STEMI is associated with smaller IS and higher MSI. Future studies are warranted to confirm these findings and to investigate potential clinical implications.

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.

Platelets and their chemokines in atherosclerosis-clinical applications

The concept of platelets as important players in the process of atherogenesis has become increasingly accepted due to accumulating experimental and clinical evidence. Despite the progress in understanding the molecular details of atherosclerosis, particularly by using animal models, the inflammatory and thrombotic roles of activated platelet s especially in the human system remain difficult to dissect, as often only the complications of atherosclerosis, i.e., stroke and myocardial infarction are definable but not the plaque burden. Platelet indices including platelet count and mean platelet volume (MPV) and soluble mediators released by activated platelets are associated with atherosclerosis. The chemokine CXCL4 has multiple atherogenic activities, e.g., altering the differentiation of T cells and macrophages by inhibiting neutrophil and monocyte apoptosis and by increasing the uptake of oxLDL and synergizing with CCL5. CCL5 is released and deposited on endothelium by activated platelets thereby triggering atherogenic monocyte recruitment, which can be attenuated by blocking the corresponding chemokine receptor CCR5. Atheroprotective and plaque stabilizing properties are attributed to CXCL12, which plays an important role in regenerative processes by attracting progenitor cells. Its release from luminal attached platelets accelerates endothelial healing after injury. Platelet surface molecules GPIIb/IIIa, GP1bα, P-selectin, JAM-A and the CD40/CD40L dyade are crucially involved in the interaction with endothelial cells, leukocytes and matrix molecules affecting atherogenesis. Beyond the effects on the arterial inflammatory infiltrate, platelets affect cholesterol metabolism by binding, modifying and endocytosing LDL particles via their scavenger receptors and contribute to the formation of lipid laden macrophages. Current medical therapies for the prevention of atherosclerotic therapies enable the elucidation of mechanisms linking platelets to inflammation and atherosclerosis.

Statins as regulators of redox signaling in platelets

SIGNIFICANCE

Reactive oxidant species (ROS) are highly reactive molecules produced by several cell lines including platelets and serve as second messenger for intracellular signaling. In recent years it became evident that ROS are also implicated in the thrombotic process. Statins are lipid lowering molecules which reduce serum cholesterol and retard atherosclerotic complication and its clinical sequelae. However there is evidence that statins may exert an antiplatelet effects by interfering with redox signaling.

RECENT ADVANCES

Experimental and clinical studies provided evidence that intra-platelet ROS formation is implicated in the process of thrombosis, as impaired ROS neutralization is associated with serious thrombotic complication and eventually death. Recent studies demonstrated that statins possess antiplatelet activity via inhibition of platelet NADPH oxidase-derived ROS formation. This effect results in down-regulation of isoprostanes, which are pro-aggregating molecules, and up-regulation of nitric oxide, which is a platelet inhibitor; such changes occurred immediately after statin's administration and were independent from lipid lowering property.

CRITICAL ISSUES

Experimental and clinical studies documented that statins possess an antithrombotic effects which may account for thrombotic-related vascular outcomes. This has been evidenced in clinical settings such as percutaneous coronary intervention, myocardial infarction and venous thrombosis. It is still unclear, however, if the statin's antithrombotic effect is dose-related.

FUTURE DIRECTIONS

Future studies should be addressed to analyze if the antiplatelet effect of statins may preferentially occur at high dosage of statins. Furthermore, the antiplatelet effects of statins could turn useful in clinical settings where the clinical efficacy of aspirin and other antiplatelet drugs are still uncertain.

Prehospital statin therapy and one-year mortality in patients with stable coronary artery disease undergoing percutaneous coronary intervention

BACKGROUND

Statins have multiple effects in patients with coronary artery disease. No studies have investigated whether chronic statin pretreatment before percutaneous coronary intervention (PCI) has an impact on long-term mortality in patients with stable angina.

METHODS

The study included 8041 patients with stable angina. At the time of PCI, 5939 patients (73.8%) were receiving statins for ≥ 1 month before procedure and 2102 patients (26.2%) were not receiving statins. The primary outcome analysis was 1-year mortality.

RESULTS

There were 192 deaths during the follow-up: 119 deaths among patients receiving statins and 73 deaths among patients not receiving statins (Kaplan-Meier estimates of 1-year mortality 2.06% and 3.59%; unadjusted hazards ratio [HR]=0.56, 95% confidence interval [CI] 0.42-0.75; P<0.001). Landmark analysis showed that almost all mortality benefit occurred in the first 30-days after PCI: 10 deaths among patients receiving statins and 22 deaths among patients not receiving statins (Kaplan-Meier estimates of 30-day death, 0.17% and 1.06%, respectively; HR=0.16, 95% CI 0.08-0.34, P<0.001). No significant difference in mortality according to statin pretreatment between 30 days and 1 year was observed (109 deaths among patients receiving statins vs 51 deaths among patients not receiving statins; Kaplan-Meier estimates 1.89% and 2.53%; HR=0.75, 95% CI 0.53-1.05, P=0.095). After adjustment in the Cox proportional hazards model, statin pretreatment was associated with a 35% reduction in the adjusted risk for 1-year mortality (adjusted HR=0.65, 95% CI 0.44-0.98, P=0.039).

CONCLUSIONS

Pretreatment with statins before PCI was associated with a significant reduction of 1-year mortality in patients with stable angina.

Reduction of platelet cytosolic phospholipase A2 activity by atorvastatin and simvastatin: biochemical regulatory mechanisms

Statins have demonstrated effects beyond reducing cholesterol level that may contribute to their clinical benefit, including effects on platelet biochemistry and function.

OBJECTIVES

To explore and compare the antiplatelet effect of two lipophilic statins (atorvastatin and simvastatin) and one hydrophilic statin (pravastatin) concerning: a) collagen-induced platelet aggregation and thromboxane A2 (TXA2) synthesis; b) the additive effect of statins on TXA2 synthesis in platelets treated with a submaximally effective concentration of aspirin and c) the biochemical mechanisms involved.

METHODS AND RESULTS

Washed human platelets were incubated with statins (1-20μM), and stimulated with collagen (1μg/ml) or arachidonic acid (AA) (200μM) and TXB2 was quantified by ELISA. Incubation with simvastatin or atorvastatin reduced (36.2% and 31.0%, respectively) collagen-induced TXB2 synthesis (p<0.05) and platelet aggregation (p<0.001), whereas pravastatin had no effects. Simultaneous incubation with a submaximally effective concentration of aspirin (1μM) and atorvastatin or simvastatin significantly increased the inhibition of TXB2 synthesis by aspirin by 4.4- and 4.1-fold, respectively. Statins did not affect AA-induced TXB2 synthesis, excluding an effect on COX-1/TXA2 synthase activities. Atorvastatin and simvastatin concentration-dependently inhibited the collagen-induced increase in cytosolic calcium and the kinetics of cPLA2 phosphorylation. Lipophilic statins reduced phosphorylation of both ERK1/2 and p38 MAPK, which regulate cPLA2 phosphorylation and calcium movement.

CONCLUSION

We report for the first time a direct downregulation by atorvastatin and simvastatin of platelet cPLA2 activity through effects on calcium and MAPK, which reduce collagen-induced TXA2 synthesis. These mechanisms might contribute to their beneficial effects, even in aspirin-treated patients.

Targeting reperfusion injury in acute myocardial infarction: a review of reperfusion injury pharmacotherapy

INTRODUCTION

Acute myocardial infarction (AMI) (secondary to lethal ischemia-reperfusion [IR]) contributes to much of the mortality and morbidity from ischemic heart disease. Currently, the treatment for AMI is early reperfusion; however, this itself contributes to the final myocardial infarct size, in the form of what has been termed 'lethal reperfusion injury'. Over the last few decades, the discovery of the phenomena of ischemic preconditioning and postconditioning, as well as remote preconditioning and remote postconditioning, along with significant advances in our understanding of the cardioprotective pathways underlying these phenomena, have provided the possibility of successful mechanical and pharmacological interventions against reperfusion injury.

AREAS COVERED

This review summarizes the evidence from clinical trials evaluating pharmacological agents as adjuncts to standard reperfusion therapy for ST-elevation AMI.

EXPERT OPINION

Reperfusion injury pharmacotherapy has moved from bench to bedside, with clinical evaluation and ongoing clinical trials providing us with valuable insights into the shortcomings of current research in establishing successful treatments for reducing reperfusion injury. There is a need to address some key issues that may be leading to lack of translation of cardioprotection seen in basic models to the clinical setting. These issues are discussed in the Expert opinion section.