Statin Pretreatment Research Articles

Periprocedural Cardiac Enzyme Elevation Predicts Adverse Outcomes

Extensive clinical investigation throughout the 1990s validated periprocedural myonecrosis as a powerful predictor of adverse outcomes, so it is surprising that this remains a contentious point. Originally derided as “enzyme leaks” or “myocardial infarctlets,” periprocedural myocardial infarction (MI) has now been definitively linked in large data sets to long-term adverse outcomes, most notably mortality. It is not, however, always directly contributory or causative. For example, a large creatine kinase (CK) elevation caused by closure of a major side branch resulting in chest pain and development of new Q waves is obviously undesirable and causally related to the interventional procedure. Alternatively, even small, asymptomatic CK elevations have been clearly associated with worse long-term outcome, and although this may in part be causally related to the procedure, it is more likely that the relationship is caused by the underlying predisposing factors that led to the periprocedural MI, such as arterial inflammation predilecting to the occurrence of embolization or to a large degree of atheroma burden leading to more myonecrosis. Under these circumstances, it is likely that the heightened inflammatory state and the diffuse disease that is present are the real causative factors for worse long-term outcomes. Recently, aspirin resistance has been demonstrated to predict periprocedural myonecrosis. Thus, both through direct causation and also as an epiphenomenon, embolization and attendant periprocedural myonecrosis are associated with short, intermediate, and long-term adverse outcomes (Table 1). This review details this evolution in thought. View this table: TABLE 1. Mechanisms Behind Periprocedural Myonecrosis Periprocedural myonecrosis is a frequent occurrence in percutaneous coronary intervention (PCI). CK or CK myocardial band (CK-MB) elevation occurs in ≈25% of patients undergoing PCI. With the advent of sensitive troponin measurements, it is clear that at least 50% of patients undergoing PCI have postprocedural troponin elevation, reflecting the frequency with which embolization occurs. However, troponin offers …

Reduced creatine kinase release with statin use at the time of myocardial infarction

Background: Statin pre-treatment has been shown to reduce myocardial infarct size in animal models. We evaluated peak creatine kinase levels in humans based on concomitant or very early statin initiation following myocardial infarction. Methods: We identified 66 consecutive patients who received a statin within 24 h of admission to our coronary care unit for myocardial infarction. Each statin patient was matched with three patients who had not received statin therapy ( n=198). Statin patients were subgrouped into those receiving statin therapy at the time of infarction ( n=44) and those initiated on statin therapy within 24 h of infarction ( n=22). Peak total creatine kinase concentrations were compared between groups. A linear regression model was developed to test for differences in peak creatine kinase after adjusting for differences between groups. Results: Patients receiving statin therapy within 24 h of admission had significantly smaller median peak creatine kinase concentrations compared to those not receiving a statin (416 IU/l [258, 992] vs. 699 IU/l [339, 1728]; p=0.020). Subgroup analysis revealed that the lower peak creatine kinase concentrations within the statin group were a result of lower creatine kinase concentrations in those patients on a statin at the time of myocardial infarction (399 IU/l [255, 869] vs. 678 IU/l [276, 1870]; p<0.05). This difference retained statistical significance after adjustment for differences between groups. Conclusion: Statin therapy at the time of myocardial infarction is associated with lower peak creatine kinase concentrations. This suggests that statins may exhibit protective effects in the setting of myocardial ischemia and/or infarction in humans.

Rising statin use and effect on ischemic stroke outcome.

BackgroundStatins (3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitors) have neuroprotective effects in experimental stroke models and are commonly prescribed in clinical practice. The aim of this study was to determine if patients taking statins before hospital admission for stroke had an improved clinical outcome.MethodsThis was an observational study of 436 patients admitted to the National Institutes of Health Suburban Hospital Stroke Program between July 2000 and December 2002. Self-reported risk factors for stroke were obtained on admission. Stroke severity was determined by the admission National Institutes of Health Stroke Scale score. Good outcome was defined as a Rankin score < 2 at discharge. Statistical analyses used univariate and multivariate logistic regression models.ResultsThere were 436 patients with a final diagnosis of ischemic stroke; statin data were available for 433 of them. A total of 95/433 (22%) of patients were taking a statin when they were admitted, rising from 16% in 2000 to 26% in 2002. Fifty-one percent of patients taking statins had a good outcome compared to 38% of patients not taking statins (p = 0.03). After adjustment for confounding factors, statin pretreatment was associated with a 2.9 odds (95% CI: 1.2–6.7) of a good outcome at the time of hospital discharge.ConclusionsThe proportion of patients taking statins when they are admitted with stroke is rising rapidly. Statin pretreatment was significantly associated with an improved functional outcome at discharge. This finding could support the early initiation of statin therapy after stroke.

Simvastatin suppresses LPS-induced Akt phosphorylation in the human monocyte cell line THP-1

Background Activation of the small GTPase, Rac, requires post-translational modification by isoprenylation. Statins interfere with this process by blocking the synthesis of isoprenoid intermediates. The protein kinase Akt is a multifunctional regulator of cell behavior that has been linked to Rac activation. We have shown that lipopolysaccharide (LPS) stimulation leads to Rac activation in THP-1 cells. Therefore, we hypothesized that LPS stimulation would also activate Akt, a downstream effector of Rac, and that this may be blocked by statin pretreatment. Materials and methods THP-1 cells were maintained in 1% fetal calf serum with or without 20 μ m simvastatin for 24 h, followed by LPS stimulation for increasing time. Cytoskeletal changes were observed using Alexa-Phalloidin. Akt was immunoprecipitated from total cell lysate. Activated Akt was detected by immunoblotting with a phospho-Akt antibody and was quantified by image densitometry. Results LPS stimulation of THP-1 cells results in membrane ruffling and cell polarization. Furthermore, LPS increased Akt activation in THP-1 cells when compared with the nonstimulated controls. Akt phosphorylation peaked after 15 min of LPS stimulation and was suppressed by pretreatment with simvastatin. Conclusions These data demonstrate that LPS stimulation leads to increased Akt phosphorylation, which can be suppressed with simvastatin pretreatment. This suggests one possible mechanism through which simvastatin could modulate LPS-induced signaling events in monocytes to improve the host response to Gram-negative infections.

Mevastatin suppresses lipopolysaccharide-induced Rac activation in the human monocyte cell line THP-1

Background. Rac is a member of the Rho family of small guanosine triphosphatases that regulate the actin cytoskeleton. Activation of Rac requires lipid modification that can be blocked by statins. Lipopolysaccharide-induced rearrangements in the actin cytoskeleton lead to changes in cell adhesion and motility that play a role in the cellular response to infection. The lipid products of phosphatidylinositol-3 kinase (PI3K) modulate Rac effector pathways and have been linked to the activation of the Rac-guanosine triphosphatase. We hypothesize that lipopolysaccharide stimulation leads to Rac activation and that this may be inhibited by statin pretreatment. Furthermore, signaling downstream of Rac is linked to PI3K; therefore, we hypothesize that a signaling complex between PI3K and Rac may be involved. Methods. THP-1 cells were maintained in 1% fetal calf serum with or without 20 μmol/L mevastatin for 24 hours, followed by lipopolysaccharide stimulation. Active Rac was precipitated from THP-1 total cell lysate and then detected by immunoblotting. The PI3K-Rac complex was immunoprecipitated from total cell lysate, and the p85 regulatory subunit of PI3K was detected by immunoblotting. Results. Lipopolysaccharide stimulation activated Rac. Rac activation was suppressed by pretreatment with mevastatin. The p85 subunit of PI3K was associated with Rac. Conclusion. Lipopolysaccharide stimulation leads to Rac activation in THP-1 cells, which may be suppressed with mevastatin pretreatment. There is an association between Rac and PI3K that demonstrates a role for PI3K in the activation of downstream Rac effector pathways. (Surgery 2003;134:306-11.)

Simvastatin ameliorates injury in an experimental model of lung ischemia-reperfusion

Objectives Statins are lipid-lowering drugs with anti-inflammatory and antioxidant properties. This study explores the potential of these commonly prescribed agents to ameliorate lung ischemia-reperfusion injury. Methods Left lungs of Long-Evans rats were rendered ischemic for 90 minutes and reperfused for up to 4 hours. Treated animals received simvastatin orally (0.5 mg/kg) for 5 days before the experiment. Injury was quantitated in terms of tissue myeloperoxidase content, vascular permeability ( 125I bovine serum albumin extravasation), and bronchoalveolar lavage leukocyte and cytokine content. Changes in nuclear translocation of transcription factors were evaluated by electromobility shift assay. Additional animals received N G-nitro- l-arginine methyl ester before ischemia-reperfusion to assess whether inhibition of nitric oxide synthase could reverse simvastatin's protective effects. The presence of nicotinamide adenine dinucleotide phosphate oxidase was also evaluated using enzyme staining both histologically and in native electrophoresis. Results Lung vascular permeability was reduced in treated animals by 71% compared with positive controls ( P < .001). Administration of N G-nitro- l-arginine methyl ester reversed this protection. The protective effects of statin pretreatment correlated with a 68% reduction in tissue myeloperoxidase content ( P < .01), marked reductions in bronchoalveolar lavage leukocyte accumulation, and decreased expression of proinflammatory cytokines. Nicotinamide adenine dinucleotide phosphate oxidase expression also decreased with statin treatment. Conclusion In addition to its antioxidant properties, the protective effects of simvastatin are likely mediated by modulation of endothelial nitric oxide synthase. The potential to pretreat recipients of lung transplantation with statins to ameliorate reperfusion injury is promising.

Marked survival benefit associated with statin pretreatment prior to percutaneous coronary intervention is dependent upon the preprocedural inflammatory status

Marked survival benefit associated with statin pretreatment prior to percutaneous coronary intervention is dependent upon the preprocedural inflammatory status

Postischemic acute renal failure is reduced by short-term statin treatment in a rat model.

Postischemic acute renal failure (ARF) is common and often fatal. Cellular mechanisms include cell adhesion, cell infiltration and generation of oxygen free radicals, and inflammatory cytokine production. Hydroxy-3-methylglutaryl coenzyme A reductase inhibitors ("statins") directly influence inflammatory mechanisms. The hypothesis that ischemia-induced ARF could be ameliorated with statin treatment was investigated and possible molecular mechanisms were analyzed in a uninephrectomized rat model. Male Sprague-Dawley rats were pretreated with cerivastatin (0.5 mg/kg) or vehicle for 3 d. Ischemic ARF was induced by left renal artery clipping for 45 min, while the right kidney was being removed. After 24 h of ARF, serum creatinine levels were increased 7.5-fold in vehicle-treated control animals with ARF, compared with sham-operated animals (P < 0.005). Statin treatment reduced the creatinine level elevation by 40% (P < 0.005). Simultaneously, ischemia-induced severe decreases in GFR were significantly ameliorated by statin treatment (sham operation, 0.95 +/- 0.09 ml/min, n = 13; ischemia without treatment, 0.06 +/- 0.02 ml/min, n = 9; ischemia with statin pretreatment, 0.21 +/- 0.03 ml/min, n = 11; P < 0.001). Furthermore, statin pretreatment prevented the occurrence of tubular necrosis, with marked loss of the brush border, tubular epithelial cell detachment, and tubular obstruction in the S3 segment of the outer medullary stripe. In addition, monocyte and macrophage infiltration was almost completely prevented, intercellular adhesion molecule-1 upregulation was greatly decreased, and inducible nitric oxide synthase expression was reduced. Fibronectin and collagen IV expression was reduced, approaching levels observed in sham-operated animals. In vehicle-treated rats with ARF, mitogen-activated protein kinase extracellular activated kinase-1/2 activity was increased and the transcription factors nuclear factor-kappaB and activator protein-1 were activated. Statin treatment reduced this activation toward levels observed in sham-operated rats. The data suggest that hydroxy-3-methylglutaryl coenzyme A reductase inhibition protects renal tissue from the effects of ischemia-reperfusion injury and thus reduces the severity of ARF. The chain of events may involve anti-inflammatory effects, with inhibition of mitogen-activated protein kinase activation and the redox-sensitive transcription factors nuclear factor-kappaB and activator protein-1.

3-Hydroxy-3-methylglutaryl coenzyme A reductase inhibitors increase the binding activity and nuclear level of Oct-1 in mononuclear cells

3-Hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase inhibitors (statins) are drugs very effective to decrease low-density lipoprotein (LDL) cholesterol. In addition, a number of studies suggest that statins have other beneficial clinical effects beyond cholesterol lowering. We recently reported that statins decrease nuclear factor kappa B (NF-κB) binding activity in monocytes and vascular smooth muscle cells. We now explored the effect of two different statins, simvastatin and atorvastatin, in the activation of the octamer transcription factor Oct-1 on the monocytic cell line THP-1. Oct-1 is a nuclear factor that represses the transcription of proinflammatory genes such as interleukin-8, CD11c/CD18, vascular cell adhesion molecule-1 (VCAM-1) and platelet endothelial cell adhesion molecule-1 (PECAM-1). Low concentrations of both statins increased Oct-1 DNA binding activity (electrophoretic mobility shift assay) that was resolved into two specific bands. The upper one was supershifted by preincubation of nuclear extracts with anti-Oct-1 antibody. The lower one was supershifted by preincubation of nuclear extracts with an anti-Oct-2 antibody, also partially competed with 100 mol/l excess of cold activator protein-1 (AP-1) and attenuated by anti-c-Jun antibody. Both statins increased Oct-1 and Oct-2 nuclear protein levels (Western blot). In contrast, neither had any effect on PMA-differentiated cells, suggesting a distinct sensitivity between circulating monocytes and resident tissular macrophages. In addition, statins did not increase Oct-lipoprotein lipase binding activity that contains an Oct-1 binding element. The mRNA expression of interleukin-8, a chemokine containing Oct sites in its promoter, was diminished by statin pretreatment. Our results indicate that simvastatin and atorvastatin increase the activity of the transcriptional repressor Oct-1 in mononuclear cells, and could thus contribute to decrease the activation of these cells. These data suggest a possible novel mechanism supporting a certain anti-inflammatory effect of these two 3-hydroxy-3-methylglutaryl-CoA reductase inhibitors.

Withdrawal of statins increases event rates in patients with acute coronary syndromes.

HMG-CoA Reductase Inhibitors (statins) reduce cardiac event rates in patients with stable coronary heart disease. Withdrawal of chronic statin treatment during acute coronary syndromes may impair vascular function independent of lipid-lowering effects and thus increase cardiac event rate. We investigated the effects of statins on the cardiac event rate in 1616 patients of the Platelet Receptor Inhibition in Ischemic Syndrome Management (PRISM) study who had coronary artery disease and chest pain in the previous 24 hours. We recorded death and nonfatal myocardial infarction during the 30-day follow-up. Baseline clinical characteristics did not differ among 1249 patients without statin therapy, 379 patients with continued statin therapy, and 86 patients with discontinued statin therapy after hospitalization. Statin therapy was associated with a reduced event rate at 30-day follow-up compared with patients without statins (adjusted hazard ratio, 0.49 [95% CI, 0.21 to 0.86]; P=0.004). If the statin therapy was withdrawn after admission, cardiac risk increased compared with patients who continued to receive statins (2.93 [95% CI, 1.64 to 6.27]; P=0.005) and tended to be higher compared with patients who never received statins (1.69 [95% CI, 0.92 to 3.56]; P=0.15). This was related to an increased event rate during the first week after onset of symptoms and was independent of cholesterol levels. In a multivariate model, troponin T elevation (P=0.005), ST changes (P=0.02), and continuation of statin therapy (P=0.008) were the only independent predictors of patient outcome. Statin pretreatment in patients with acute coronary syndromes is associated with improved clinical outcome. However, discontinuation of statins after onset of symptoms completely abrogates this beneficial effect.