Association of pravastatin and left ventricular mass in hypercholesterolemic patients: role of 8-iso-prostaglandin f2alpha formation

Use of Statins in Heart Failure with Preserved Ejection Fraction: Current Evidence and Perspectives

Systemic inflammation and coronary microvascular endothelial dysfunction are essential pathophysiological factors in heart failure (HF) with preserved ejection fraction (HFpEF) that support the use of statins. The pleiotropic properties of statins, such as anti-inflammatory, antihypertrophic, antifibrotic, and antioxidant effects, are generally accepted and may be beneficial in HF, especially in HFpEF. Numerous observational clinical trials have consistently shown a beneficial prognostic effect of statins in patients with HFpEF, while the results of two larger trials in patients with HFrEF have been controversial. Such differences may be related to a more pronounced impact of the pleiotropic properties of statins on the pathophysiology of HFpEF and pro-inflammatory comorbidities (arterial hypertension, diabetes mellitus, obesity, chronic kidney disease) that are more common in HFpEF. This review discusses the potential mechanisms of statin action that may be beneficial for patients with HFpEF, as well as clinical trials that have evaluated the statin effects on left ventricular diastolic function and clinical outcomes in patients with HFpEF.

Statin's role on blood pressure levels: Meta-analysis based on randomized controlled trials

Statins have been proven to be effective in minimizing the risk of cardiovascular adverse events, however, their effect on BP variability is debatable with respect to their significance and their use as a potential anti-hypertensive. Using a meta-analysis approach, the aim of this study was to explore whether certain statins have the potential to lower blood pressure (BP). For the period 2002-2022, Scopus, PubMed, Web of Science, and the Cochrane Central Register of Controlled Trials databases were searched for the studies that examined the effect of statins on blood pressure in normotensive or hypertensive individuals. Randomized controlled clinical trials that investigated this effect were included based on our inclusion criteria. Our primary outcomes were changes in systolic and diastolic blood pressure (DBP). The final analysis of the study included 49 RCTs involving 45 173 participants randomized to receive either statins or placebo. Among the two groups, the total weighted mean difference (WMD) for systolic blood pressure (ΔSBP) was -1.42 (95% CI: -2.38, -0.46; p = .004) and diastolic blood pressure (ΔDBP) was 0.82 (95% CI: -1.28, -0.36; p = .0005). Despite various studies suggesting the efficacy of statins in blood pressure lowering to be significant and non-significant both, we observed a decrease in SBP and DBP both, although the change was not as large and could be considered significant. A large multicenter, multi-ethnic, large sample pool size, and a long period follow-up study is still required to assert these claims.

A High-Cholesterol Diet Increases Toll-like Receptors and Other Harmful Factors in the Rabbit Myocardium: The Beneficial Effect of Statins

Background: A high-cholesterol diet (HCD) induces vascular atherosclerosis through vascular inflammatory and immunological processes via TLRs. The aim of this study is to investigate the mRNA expression of TLRs and other noxious biomarkers expressing inflammation, fibrosis, apoptosis, and cardiac dysfunction in the rabbit myocardium during (a) high-cholesterol diet (HCD), (b) normal diet resumption and (c) fluvastatin or rosuvastatin treatment. Methods: Forty-eight male rabbits were randomly divided into eight groups (n = 6/group). In the first experiment, three groups were fed with HCD for 1, 2 and 3 months. In the second experiment, three groups were fed with HCD for 3 months, followed by normal chow for 1 month and administration of fluvastatin or rosuvastatin for 1 month. Control groups were fed with normal chow for 90 and 120 days. The whole myocardium was removed; total RNA was isolated from acquired samples, and polymerase chain reaction, reverse transcription PCR and quantitative real-time PCR were performed. Results: mRNA of TLRs 2, 3, 4 and 8; interleukin-6; TNF-a; metalloproteinase-2; tissue inhibitor of metalloproteinase-1; tumor protein 53; cysteinyl aspartate specific proteinase-3; and brain natriuretic peptide (BNP) increased in HCD. Statins but not resumption of a normal diet decreased levels of these biomarkers and increased levels of antifibrotic factors. Conclusions: HCD increases the levels of TLRs; inflammatory, fibrotic and apoptotic factors; and BNP in the rabbit myocardium. Atherogenic diets adversely affect the myocardium at a molecular level and are reversed by statins.

Statins: Neurobiological underpinnings and mechanisms in mood disorders

Statins (3-hydroxy-3-methylglutaryl-coenzyme A reductase inhibitors) treat dyslipidaemia and cardiovascular disease by inhibiting cholesterol biosynthesis. They also have immunomodulatory and anti-inflammatory properties. Beyond cardiovascular disease, cholesterol and inflammation appear to be components of the pathogenesis and pathophysiology of neuropsychiatric disorders. Statins may therefore afford some therapeutic benefit in mood disorders. In this paper, we review the pathophysiology of mood disorders with a focus on pharmacologically relevant pathways, using major depressive disorder and bipolar disorder as exemplars. Statins are discussed in the context of these disorders, with particular focus on the putative mechanisms involved in their anti-inflammatory and immunomodulatory effects. Recent clinical data suggest that statins may have antidepressant properties, however given their interactions with many known biological pathways, it has not been fully elucidated which of these are the major determinants of clinical outcomes in mood disorders. Moreover, it remains unclear what the appropriate dose, or appropriate patient phenotype for adjunctive treatment may be. High quality randomised control trials in concert with complementary biological investigations are needed if the potential clinical effects of statins on mood disorders, as well as their biological correlates, are to be better understood.

Speckle-Tracking Echocardiography for Detecting Subclinical Left Ventricular Dysfunction in Patients With Familial Hypercholesterolemia

Myocardial ischemia and left ventricular dysfunction have been documented in young adults with familial hypercholesterolemia. We investigated whether speckle-tracking echocardiography can be used to detect subclinically impaired global and regional myocardial function in patients with this lipid disorder. This single-center study included 47 patients with familial hypercholesterolemia and 37 healthy control subjects who underwent transthoracic Doppler echocardiography and speckle-tracking echocardiography from January 2003 through December 2016. Conventional echocardiographic and strain parameters in the 2 groups were analyzed and compared. Left ventricular dimensions were significantly larger at end-diastole (P=0.02) and end-systole (P=0.013), left ventricular walls were significantly thicker (P <0.0001), and the early transmitral/early diastolic mitral annular velocity ratio was significantly higher (P=0.006) in the patient group than in the control group. In the patient group, global longitudinal and circumferential strain values were significantly lower (P <0.0001) and global radial strain values significantly higher (P=0.006); all segmental longitudinal strain (P <0.04) and most segmental circumferential strain values (P ≤0.01) were significantly lower; and some segmental radial strains, especially at the apex, were significantly higher (P ≤0.04). However, average longitudinal, circumferential, and radial strains in the different segments of the 3 main coronary artery territories were significantly lower in the patient group (P <0.01). Global longitudinal strain (r=0.561; P=0.001) and global circumferential strain (r=0.565; P <0.0001) were inversely correlated with low-density-lipoprotein cholesterol levels. We conclude that speckle-tracking echocardiography can be used to detect subclinical global and regional systolic abnormalities in patients with familial hypercholesterolemia.

New statin use and left ventricular structure: Estimating long-term associations in the Multi-Ethnic Study of Atherosclerosis (MESA)

PURPOSE

Only small and short-term studies have evaluated statins in relation to changes in heart structure. We estimated the association between new statin use and 10-year remodeling of the left ventricle.

METHODS

The Multi-Ethnic Study of Atherosclerosis collected data on statin use over approximately 10 years, conducting cardiac magnetic resonance (CMR) imaging at baseline and the 10-year exam. Participants were free of baseline cardiovascular disease, and we excluded users of statins at baseline. Statin initiation was defined as a report of current use at any of the 4 subsequent exams. Primary outcomes were the change in left ventricular mass index (LVMI; % predicted by height, weight, and sex) and mass-to-volume ratio. Associations were estimated in a propensity score-matched analysis.

RESULTS

A total of 3113 participants (53% female; 40% European-American, 25% African-American, 22% Hispanic-American, and 13% Chinese-American) were eligible; 2431 returned for follow-up CMR imaging after a median of 9.4 years. Statin therapy (moderate dose, 76%) was started by 36% of participants (N = 872). We excluded 42 participants with incident myocardial infarction. Compared with nonuse, statin use was associated with less 10-year progression in LVMI (-2.35 percentage points; 95% CI, -4.24 to -0.47; P = .01) and mass-to-volume ratio (-0.03 absolute difference; 95% CI, -0.07 to -0.00; P = .02); effects were small in magnitude. A dose response was observed: Higher statin dose was associated with less LVMI progression.

CONCLUSIONS

In contrast to previous small studies, we found very modest associations between statin use and indices of left ventricular remodeling over 10 years in this prospective study of a diverse cohort.

Assessing Free-Radical-Mediated DNA Damage during Cardiac Surgery: 8-Oxo-7,8-dihydro-2'-deoxyguanosine as a Putative Biomarker

Coronary artery bypass grafting (CABG), one of the most common cardiac surgical procedures, is characterized by a burst of oxidative stress. 8-Oxo-7,8-dihydro-2′-deoxyguanosine (8-oxodG), produced following DNA repairing, is used as an indicator of oxidative DNA damage in humans. The effect of CABG on oxidative-induced DNA damage, evaluated through the measurement of urinary 8-oxodG by a developed and validated liquid chromatography-tandem mass spectrometry (LC-MS/MS) method in 52 coronary artery disease (CAD) patients, was assessed before (T0), five days (T1), and six months (T2) after CABG procedure. These results were compared with those obtained in 40 subjects with cardiovascular risk factors and without overt cardiovascular disease (CTR). Baseline (T0) 8-oxodG was higher in CAD than in CTR (p = 0.035). A significant burst was detected at T1 (p = 0.019), while at T2, 8-oxodG levels were significantly lower than those measured at T0 (p < 0.0001) and comparable to those found in CTR (p = 0.73). A similar trend was observed for urinary 8-iso-prostaglandin F_2α (8-isoPGF_2α), a reliable marker of oxidative stress. In the whole population baseline, 8-oxodG significantly correlated with 8-isoPGF_2α levels (r = 0.323, p = 0.002). These data argue for CABG procedure in CAD patients as inducing a short-term increase in oxidative DNA damage, as revealed by 8-oxodG concentrations, and a long-term return of such metabolite toward physiological levels.

Reactive Oxygen Species: A Key Hallmark of Cardiovascular Disease

Cardiovascular diseases (CVDs) have been the prime cause of mortality worldwide for decades. However, the underlying mechanism of their pathogenesis is not fully clear yet. It has been already established that reactive oxygen species (ROS) play a vital role in the progression of CVDs. ROS are chemically unstable reactive free radicals containing oxygen, normally produced by xanthine oxidase, nicotinamide adenine dinucleotide phosphate oxidase, lipoxygenases, or mitochondria or due to the uncoupling of nitric oxide synthase in vascular cells. When the equilibrium between production of free radicals and antioxidant capacity of human physiology gets altered due to several pathophysiological conditions, oxidative stress is induced, which in turn leads to tissue injury. This review focuses on pathways behind the production of ROS, its involvement in various intracellular signaling cascades leading to several cardiovascular disorders (endothelial dysfunction, ischemia-reperfusion, and atherosclerosis), methods for its detection, and therapeutic strategies for treatment of CVDs targeting the sources of ROS. The information generated by this review aims to provide updated insights into the understanding of the mechanisms behind cardiovascular complications mediated by ROS.

Intermedin1-53 Protects Against Myocardial Fibrosis by Inhibiting Endoplasmic Reticulum Stress and Inflammation Induced by Homocysteine in Apolipoprotein E-Deficient Mice

AIM

Endoplasmic reticulum stress (ERS) and inflammation participate in cardiac fibrosis. Importantly, a novel paracrine/autocrine peptide intermedin_1-53 (IMD_1-53) in the heart inhibits myocardial fibrosis in rats. However, the mechanisms are yet to be fully elucidated.

METHODS

Myocardial fibrosis in apolipoprotein E-deficient (ApoE -/-) mice and neonatal rat cardiac fibroblasts (CFs) were induced using homocysteine (Hcy).

RESULTS

IMD_1-53 inhibited myocardial fibrosis in vivo and in vitro. Picrosirius red staining showed that IMD_1-53 reduced myocardial interstitial collagen deposition in ApoE-/- mice treated with Hcy and decreased the expression of myocardial collagen I and III, which was further verified in rat CFs. IMD_1-53 attenuated myocardial hypertrophy, as shown by cardiomyocyte cross-sectional area, ratio of heart weight to body weight, and mRNA levels of atrial natriuretic peptide and brain natriuretic peptide. IMD_1-53 inhibited the upregulation of ERS hallmarkers such as glucose-regulated protein 78 (GRP78), GRP94, activating transcription factor 6 (ATF6), ATF4, inositol-requiring enzyme 1α, spliced-X-box-binding protein-1, protein kinase receptor-like ER kinase, and eukaryotic translation initiation factor 2α in mouse myocardium and rat CFs treated with Hcy. In addition, IMD_1-53 decreased the production of inflammatory factors such as tumor necrosis factor-α, monocyte chemotactic protein-1, interleukin-6 (IL-6), and IL-1β in the mouse myocardium and rat CFs treated with Hcy. Concurrently, IMD_1-53 ameliorated the expression of nuclear factor-κB, transforming growth factor-β1, and c-Jun N-terminal kinase in the mouse myocardium and rat CFs treated with Hcy.

CONCLUSIONS

IMD potentially protects against myocardial fibrosis induced by Hcy in ApoE-/- mice, possibly via attenuating myocardial ERS and inflammation.

Statin Induced Regression of Cardiomyopathy Trial: A Randomized, Placebo-controlled Double-blind Trial

Background:

Hypertrophic cardiomyopathy (HCM), characterized by a thickened, fibrotic myocardium, remains the most common cause of sudden cardiac death in young adults. Based on animal and clinical data, we hypothesized that atorvastatin would induce left ventricular (LV) mass regression.

Methods:

Statin Induced Regression of Cardiomyopathy Trial (SIRCAT) was a randomized, placebo-controlled study. The primary endpoint was change in LV mass measured by cardiac magnetic resonance imaging 12 months after treatment with once-daily atorvastatin 80 mg or placebo. A key secondary endpoint was diastolic dysfunction measured echocardiographically by transmitral flow velocities. SIRCAT is registered with www.clinicaltrials.gov (NCT00317967).

Results:

Of 222 screened patients, 22 were randomized evenly to atorvastatin and placebo. The mean age was 47 ± 10 years, and 15 (68%) were male. All subjects completed the protocol. At baseline, LV masses were 197 ± 76 g and 205 ± 82 g in the placebo and atorvastatin groups, respectively. After 12 months treatment, the LV masses in the placebo and atorvastatin groups were 196 ± 80 versus 206 ± 92 g (P = 0.80), respectively. Echocardiographic indices were not different in the two groups at baseline. After 12 months, diastolic dysfunction as assessed using transmitral flow velocities E/E', A/A', and peak systolic mitral velocity showed no benefit from atorvastatin.

Conclusions:

In patients with HCM, atorvastatin did not cause LV mass regression or improvements in LV diastolic function.

Waon therapy attenuates cardiac hypertrophy and promotes myocardial capillary growth in hypertensive rats: a comparative study with fluvastatin

Cardiac hypertrophy and fibrosis in heart failure with preserved ejection fraction are associated with a pro-inflammatory state and reduced NO bioavailability. Effects on myocardial structural and molecular alterations were compared between Waon therapy (WT; repeated dry sauna therapy) and statin in hypertensive rats. Seven-week-old Dahl salt-sensitive rats were assigned to 4 groups: low-salt (LS) diet, high-salt (HS) diet, HS diet with oral fluvastatin (FL; 10 mg/kg/day for 4 weeks) starting from the age of 9 weeks, and HS diet with WT treatment in a far-infrared dry sauna (39 °C for 15 min followed by 34 °C for 20 min once daily for 4 weeks). HS rats developed left ventricular (LV) hypertrophy with preserved LV systolic function. WT reduced LV wall thickness and myocyte cross-sectional area along with decreased levels of myocardial ANP and BNP mRNA expression compared with HS rats. Reduction in LV fibrosis and increase in capillary density in WT animals were accompanied by reductions in myocardial levels of TGF-β1, MMP2, p22(phox) and gp91(phox) mRNA expression, and increases in myocardial levels of VEGF and HSP90 mRNA and phosphorylated eNOS protein. These effects were comparable between WT and FL animals. WT improves structural and molecular alterations in salt-induced hypertensive rats similarly to fluvastatin.

Early myocardial deformation changes in hypercholesterolemic and obese children and adolescents: a 2D and 3D speckle tracking echocardiography study

Dyslipidemia and obesity are considered strong risk factors for premature atherosclerotic cardiovascular disease and increased morbidity and mortality and may have a negative impact on myocardial function.Our purpose was to assess the presence of early myocardial deformation abnormalities in dyslipidemic children free from other cardiovascular risk factors, using 2-dimensional speckle tracking echocardiography (2DSTE) and 3-dimensional speckle tracking echocardiography (3DSTE).We studied 80 consecutive nonselected patients (6-18 years of age) with hypercholesterolemia (low-density lipoprotein [LDL] cholesterol levels >95th percentile for age and sex). Forty of them had normal weight and 40 were obese (body mass index >95th percentile for age and sex). Forty healthy age-matched children were selected as controls. Left ventricular (LV) global longitudinal, circumferential, and radial strains were calculated by 2DSTE and 3DSTE. Global area strain (GAS) was calculated by 3DSTE as percentage of variation in surface area defined by the longitudinal and circumferential strain vectors. Right ventricular (RV) global and free-wall longitudinal strain and LV and RV diastolic strain rate parameters were obtained. Data analysis was performed offline.LV global longitudinal strain and GAS were lower in normal-weight and obese dyslipidemic children compared with normal controls and reduced in obese patients compared with normal-weight dyslipidemic children. LV early diastolic strain rate was lower compared with normals. RV global and free-wall longitudinal strain was significantly reduced in obese patients when compared with the control group. A significant inverse correlation was found between LV strain, LDL cholesterol levels, and body mass index.2DSTE and 3DSTE show LV longitudinal strain and GAS changes in dyslipidemic children and adolescents free from other cardiovascular risk factors or structural cardiac abnormalities. Obesity causes an additive adverse effect on LV strain parameters and RV strain impairment.

Association of hypercholesterolemia and cardiac function evaluated by speckle tracking echocardiography in a rabbit model

Background

Although hypercholesterolemia is a major risk factor for coronary artery disease (CAD), only limited data are available regarding its direct effect on myocardial function apart from CAD. The aim of this study was to evaluate LV systolic function using speckle-tracking echocardiography and investigate the relationship between hypercholesterolemia and myocardial function.

Methods

Twenty-eight rabbits were randomly divided into three groups: 8 were fed normal chow for 3 months (group 1) and the remaining 20 were fed an atherogenic diet for 2 (group 2) or 3 months (group 3). Global systolic radial, circumferential and longitudinal peak strain were calculated. Serum total cholesterol (TC), low density lipoprotein cholesterol (LDL-C) and myocardial cholesterol levels were measured.

Results

Global systolic longitudinal strain were both decreased in the group 2 and 3 (P < 0.001), whereas radial strain were increased (P < 0.001) compared with group 1. Global circumferential strain in the group 3 was significantly reduced (P < 0.001). Serum and myocardial cholesterol concentration markedly increased in the group 2 and group 3 (P < 0.001). There was a significant inverse correlation between longitudinal strain and serum TC, LDL-C as well as myocardial cholesterol levels (r = - 0.723, r = - 0.794, r = - 0.700, P both < 0.001). A significant negative correlation was also noted between circumferential strain and serum TC, LDL-C as well as myocardial cholesterol levels (r = - 0.518, P = 0.007; r = - 0.691, P < 0.001; r = - 0.659, P < 0.001). A significant positive correlation was found between radial strain and serum TC, LDL-C as well as myocardial cholesterol levels (r = 0.432, P = 0.028; r = 0.602, P = 0.001; r = 0.469, P = 0.016).

Conclusion

Although LV morphology and ejection fractions were not different among the three groups, elevated concentration of cholesterol, especially in serum LDL-C, was significantly associated with LV systolic dysfunction. The findings also indicate that reductions in longitudinal was the first appeared, followed by circumferential, and was compensated for by increasing radial strain.

Rac1-mediated effects of HMG-CoA reductase inhibitors (statins) in cardiovascular disease

SIGNIFICANCE

HMG-CoA reductase inhibitors (statins) lower serum cholesterol concentrations and are beneficial in the primary and secondary prevention of coronary heart disease. The positive clinical effects have only partially been reproduced with other lipid-lowering interventions suggesting potential statin effects in addition to cholesterol lowering. In experimental models, direct beneficial cardiovascular effects that are mediated by the inhibition of isoprenoids have been documented, which serve as lipid attachments for intracellular signaling molecules such as small Rho guanosine triphosphate-binding proteins, whose membrane localization and function are dependent on isoprenylation.

RECENT ADVANCES

Rac1 GTPase is an established master regulator of cell motility through the cortical actin reorganization and of reactive oxygen species generation through the regulation of nicotinamide adenine dinucleotide phosphate (NADPH) oxidase activity.

CRITICAL ISSUES

Observations in cells, animals, and humans have implicated the activation of Rac1 GTPase as a key component of cardiovascular pathologies, including the endothelial dysfunction, cardiac hypertrophy and fibrosis, atrial fibrillation, stroke, hypertension, and chronic kidney disease. However, the underlying signal transduction remains incompletely understood.

FUTURE DIRECTIONS

Based on the recent advance made in Rac1 research in the cardiovascular system by using mouse models with transgenic overexpression of activated Rac1 or conditional knockout, as well as Rac1-specific small molecule inhibitor NSC 23766, the improved understanding of the Rac1-mediated effects statins may help to identify novel therapeutic targets and strategies.

Antihypertensive effects of statins: a meta-analysis of prospective controlled studies

In experimental studies, statins have been shown to lower blood pressure through increased nitric oxide bioavailability and improved arterial compliance. The clinical significance of this effect remains poorly documented. The authors performed a meta-analysis of the effect of statins on systolic blood pressure (SBP) and diastolic blood pressure (DBP) including prospective randomized, controlled trials of statin therapy. EMBASE and MEDLINE searches for studies in which patients were randomized to treatment with a statin plus standard treatment (or placebo) vs standard treatment (or placebo) were conducted. Studies that provided data on SBP and DBP values before the initiation of the treatment and at the end of the follow-up period were included. A total of 40 studies with 51 comparison groups examining 22,511 controls and 22,602 patients taking statins were examined. Mean SBP in the statin group decreased by 2.62 mm Hg (95% confidence interval [CI], -3.41 to -1.84; P<.001) and DBP by 0.94 mm Hg (95% CI, -1.31 to -0.57; P<.001). In studies including hypertensive patients, the decrease in blood pressures with statins was slightly greater (SBP, -3.07 mm Hg; 95% CI, -4.00 to -2.15 and DBP, 1.04; 95% CI, -1.47 to -0.61). Similarly, statins effectively reduced SBP in diabetic patients. In this large meta-analysis of prospective controlled studies, the authors found a small but statistically significant reduction of SBP in patients taking statins. The decrease in blood pressure may contribute to the pleiotropic effect of statins in reducing cardiovascular risk.

The effects of statins on blood pressure in normotensive or hypertensive subjects--a meta-analysis of randomized controlled trials

OBJECTIVE

The aim of this meta-analysis was to investigate whether statin therapy is associated with blood pressure (BP)-lowering in patients with or without hypertension.

BACKGROUND

The beneficial effects of statins on the cardiovascular system may in part be related to effects beyond lipid-lowering. It has been suggested that statins may reduce BP; however the available data are still ambiguous and often conflicting.

METHODS

Data from Scopus, PubMed, Web of Science, and the Cochrane Central Register of Controlled Trials for the years 1966-January 2012 were searched for studies that investigated the effect of statins on BP in normotensive or in hypertensive subjects. We included all randomized controlled clinical trials that investigated this effect. Changes in systolic and diastolic BP were the key outcomes of interest.

RESULTS

The final analysis included 18 trials and 5628 subjects (4692 normotensive and 936 hypertensive patients) randomized to receive either statins or placebo. The weighted mean difference of systolic (∆SBP) and diastolic blood pressure (∆DBP) in normotensive patients for the 11 statin trials included were 0.03 (95% CI: -0.95-1.02; p = 0.95) and -0.28 (95% CI: -0.80-0.24; p = 0.29), respectively. For hypertensive patients treated with statins (8 trials) the weighted mean difference of ∆SBP and ∆DBP were 1.45 (95% CI: -0.49-3.39; p = 0.14) and -1.32 (95% CI: -3.93-1.28; p = 0.32) respectively.

CONCLUSIONS

Despite previous suggestions statin therapy in normotensive or hypertensive patients does not lead to significant reductions in systolic or diastolic BP.

Pleiotropic effects of statins: evidence for benefits beyond LDL-cholesterol lowering

Evidence is mounting that 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitors (statins) have a number of pleiotropic effects over and above their lipid-lowering properties in patients with cardiovascular disease and heart failure. In addition to lowering low-density lipoprotein cholesterol and triglyceride levels, several studies have shown statins to improve survival and reduce the risk of major cardiovascular events in patients without established cardiovascular disease but with cardiovascular risk factors. Statins have also been shown to have beneficial effects, including a reduction in all-cause mortality, in patients with ischemic and non-ischemic congestive heart failure, and have been associated with a reduced incidence of atrial fibrillation. Furthermore, statins have been associated with improvements in renal function in patients with pre-existing renal disease or the prevention of new-onset renal dysfunction, as well as improvements in lung function in patients with chronic obstructive pulmonary disease or age-related decline in lung function. The pleiotropic effects of statins appear to result from improvements in endothelial function, a reduction in inflammatory mediators, a decline in the development of atheroma through the stabilization of atheromatous plaques, and the inhibition of cardiac hypertrophy through an antioxidant mechanism. Long-term statin use may reduce morbidity and mortality rates in a broad range of patients, and most patients at high risk of cardiovascular disease may benefit from statin treatment; however, further data are required to demonstrate conclusively whether these trends are truly independent of the lipid-lowering effects of statins.

F2-isoprostanes as an indicator and risk factor for coronary heart disease

Coronary heart disease (CHD) is the leading single cause of death in the United States and most Western countries, killing more than 400,000 Americans per year. Although CHD often manifests suddenly as a fatal myocardial infarction, the atherosclerosis that gives rise to the infarction develops gradually and can be markedly slowed or even reversed through pharmacological and lifestyle interventions. These same atherosclerotic processes also drive related vascular diseases such as stroke and peripheral artery disease, and individuals surviving occlusive events often develop additional complications including ischemic cardiomyopathy and heart failure. Therefore, better detection of subclinical atherosclerosis, along with more effective treatments, could significantly reduce the rate of death from CHD and related vascular diseases in the United States. In recent years, oxidation of polyunsaturated fatty acids (PUFAs) in plasma lipoproteins has been postulated to be a critical step in the development of atherosclerosis. If so, then monitoring lipid peroxidation should be a useful indicator of disease risk and progression. This review focuses on the evidence that specific PUFA peroxidation products, the F(2)-isoprostanes, are useful biomarkers that could potentially be utilized as indicators of CHD.

Simvastatin inhibited cardiac hypertrophy and fibrosis in apolipoprotein E-deficient mice fed a "Western-style diet" by increasing PPAR α and γ expression and reducing TC, MMP-9, and Cat S levels

AIM

The examine the cardiac hypertrophy and fibrosis in apolipoprotein E-deficient mice (ApoE-/- mice) fed a "Western-style diet" and the effect of simvastatin intervention.

METHODS

Male ApoE-/- mice (n=36) were fed a "Western-style diet" from the age of 8 weeks. After 16 weeks, they were randomly given either simvastatin (25 mg·kg⁻¹·d⁻¹) or normal saline (control group) by gavage for 8, 16, or 24 weeks. The left ventricular (LV) wall thickness and diameter of the myocardial cells were determined with Hematoxylin-Eosin stain, and the level of fibrosis of the myocardial matrix was assessed with Masson stain. Real-time quantitative polymerase chain reaction and Western blotting analysis were used to determine the mRNA and protein expression of matrix metalloproteinase-9 (MMP-9), Cathepsin S (Cat S), and the peroxisome proliferator-activated receptors (PPARs) in the myocardium of ApoE-/- mice.

RESULTS

ApoE-/- mice fed a "Western-style diet" showed an significant age-dependent increase in total cholesterol (TC), LV wall thickness, myocardial cell diameter and LV collagen content (P<0.05). The simvastatin treatment group showed significantly reduced LV wall thickness, myocardial cell diameters and LV collagen content at 40 weeks when compared with the control group (P<0.05). Furthermore, treatment with simvastatin also significantly inhibited the mRNA and protein expressions of MMP-9 and Cat S as well as increased the mRNA and protein expressions of PPAR alpha and PPAR gamma at 32 and 40 weeks compared with the control group (P<0.05).

CONCLUSION

ApoE-/- mice fed a "Western-style diet" had cardiac hypertrophy and fibrosis, which worsened with age. Simvastatin treatment inhibits the development of cardiac hypertrophy and fibrosis, and this effect may be mediated through increased levels of PPAR alpha and PPAR gamma and reduced levels of TC, MMP-9, and Cat S.

The inhibitory effects of rosiglitazone on cardiac hypertrophy through modulating the renin-angiotensin system in diet-induced hypercholesterolemic rats

Cardiac hypertrophy is not only an adaptational state before heart failure but also is an independent risk factor for ischemia, arrhythmia, and sudden death. However, the direct effects of hypercholesterolemia on the myocardium and mechanisms are not completely understood. It has been demonstrated that peroxisome proliferator-activated receptor-gamma (PPARgamma) ligand agonists attenuate cardiac hypertrophy through anti-inflammatory effects. The present study investigated the effects of PPARgamma agonists on hypercholesterolemia-dependent, renin-angiotensin-system-related cardiac hypertrophy. The findings showed that left ventricular hypertrophy, eminent cardiomyocyte hypertrophy, and lipid deposits in myocardium were observed in the rats fed a cholesterol-rich diet for 6 months, while these characteristic pathological alterations and the increase in angiotensin II (ANG II) level and over-expression of angiotensin II type 1 receptor (AT(1)R) in the left ventricular tissues induced by the cholesterol-rich diet were significantly suppressed to equal extents by rosiglitazone and irbesartan. In contrast, expression of angiotensin II type 2 receptor (AT(2)R) was upregulated by these two drugs. In addition, lipid metabolism was markedly improved. The above findings suggest that the cardioprotection of the PPARgamma agonist against cardiac hypertrophy evoked by hypercholesterolemia in rats is mediated partially by the improvement of lipid profile, the reduction of ANG II level in the local tissue along with the downregulation of AT(1)R expression, and upregulation of AT(2)R expression.

Effects of pravastatin on functional capacity in patients with chronic obstructive pulmonary disease and pulmonary hypertension

PH (pulmonary hypertension) often complicates the disease course of patients with COPD (chronic obstructive pulmonary disease) and is an indication of a worse prognosis. In the present study, we assessed whether pravastatin administration was effective in improving PH and exercise capacity in COPD patients with PH, and whether the pulmonary protection was mediated by inhibiting ET-1 (endothelin-1) production. In a double-blind parallel design, 53 COPD patients with PH were randomly assigned to receive either placebo or pravastatin (40 mg/day) over a period of 6 months at a medical centre. Baseline characteristics were similar in both groups. The exercise time remained stable throughout the study in the placebo group. After 6 months, the exercise time significantly increased 52% from 660±352 to 1006±316 s (P<0.0001) in pravastatin-treated patients. With pravastatin, echocardiographically derived systolic PAP (pulmonary artery pressure) decreased significantly from 47±8 to 40±6 mmHg. There was significant improvement in the Borg dyspnoea score after administering pravastatin. Despite unchanged plasma ET-1 levels throughout the study, urinary excretion of the peptide was decreased and significantly correlated with an improvement in exercise time in pravastatin-treated patients (r=−0.47, P=0.01). In conclusion, pravastatin significantly improved exercise tolerance, and decreased PH and dyspnoea during exercise in COPD patients with PH, probably by inhibiting ET-1 synthesis.

The impact of statin use on atrial fibrillation

The aim of the present systematic review is to present an overview of the evidence linking atrial fibrillation (AF), inflammation and oxidative stress, with emphasis on the potential of statins to decrease the incidence of different types of AF, including new-onset AF, after electrical cardioversion (EC) and after cardiac surgery. Observational and clinical trials have studied the impact of statin therapy on new-onset, post-EC or postoperative AF. Data from different observational trials have shown that treatment with statins significantly reduces the incidence of new-onset AF in the primary and secondary prevention. The data are insufficient to recommend the use of statins before EC. Finally, perioperative statin therapy may represent an important non-antiarrhythmic adjunctive therapeutic strategy for the prevention of postoperative AF.

Spectrum of pleiotropic effects of statins in heart failure

The syndrome of heart failure is characterized by increased levels of circulating inflammatory mediators, which have been implicated in the pathogenesis of heart failure. Recently, a number of studies have suggested that statins may exert salutary effects in patients who have heart failure by virtue of their pleiotropic (non-lipid lowering) actions. This article focuses on the non-lipid lowering effects of statins, with an emphasis on the anti-inflammatory properties of these agents.

Antioxidative effects of statins

HMG CoA reductase inhibitors (statins) have been shown to be effective lipid lowering agents and are beneficial in the primary and secondary prevention of coronary heart disease. However, the overall benefits observed with statins appear to be greater than what might be expected from changes in lipid levels alone and the positive effects have only partially been reproduced with other lipid lowering drugs, suggesting effects in addition to cholesterol lowering. In experimental models, many of the cholesterol-independent effects of statins are mediated by inhibition of isoprenoids, which serve as lipid attachments for intracellular signalling molecules such as small Rho guanosine triphosphate-binding proteins, whose membrane localization and function are dependent on isoprenylation. This review summarizes the effects of statins on endothelial function and oxidative stress.

The influence of pravastatin and atorvastatin on markers of oxidative stress in hypercholesterolemic humans

OBJECTIVES

The aim of this study was to determine the effects of pravastatin and atorvastatin on markers of oxidative stress in plasma.

BACKGROUND

Hydroxymethylglutaryl coenzyme A reductase inhibitors reduce low-density lipoprotein cholesterol (LDL-C) and cardiovascular risk, but their effects on circulating biomarkers of oxidative stress are not well-defined.

METHODS

Hypercholesterolemic subjects (n = 120, ages 21 to 80 years with LDL-C 130 to 220 mg/dl) were randomized in a double-blind, parallel design to pravastatin 40 mg/day (prava40), atorvastatin 10 mg/day (atorva10), atorvastatin 80 mg/day (atorva80), or placebo. At baseline and 16 weeks, urinary isoprostanes (8, 12-iso-iPF(2 alpha)-VI isoform), plasma lipoprotein-associated phospholipase A2 (Lp-PLA2), Mercodia oxidized LDL (OxLDL) with antibody 4E6, oxidized phospholipids/apolipoprotein B-100 particle (OxPL/apoB) with antibody E06, immunoglobulin (Ig)G/IgM autoantibodies to malondialdehyde (MDA)-LDL, and apolipoprotein B (apoB)-immune complexes (IC) were measured.

RESULTS

After 16 weeks, there were no significant changes in urinary 8, 12-iso-iPF(2 alpha)-VI. The Lp-PLA2 and OxLDL were reduced in statin-treated groups, but after adjusting for apoB, only prava40 led to a reduction in Lp-PLA2 (-15%, p = 0.008) and atorva10 to a decrease in OxLDL (-12.9%, p = 0.01). The OxPL/apoB increased 25.8% (p < 0.01) with prava40 and 20.2% (p < 0.05) with atorva80. There were no changes in MDA-LDL autoantibodies, but significant decreases in IC were noted.

CONCLUSIONS

This study suggests that statin therapy results in variable effects on oxidative stress markers in hypercholesterolemic subjects. Future outcome studies should collectively assess various oxidative markers to define clinical utility.

Statins: a perspective for left ventricular hypertrophy treatment

Left ventricular hypertrophy (LVH), despite its adaptive nature, is associated with an increased risk of cardiovascular morbidity and mortality. Achievement of LVH regression is thus considered a principal therapeutic aim. However, regression of LVH induced by various therapeutic means may exhibit differing patterns, with variable biological implications. Inhibitors of 3-hydroxy-3-methylglutaryl coenzyme A reductase (statins) have been shown to induce prevention or regression of LVH in different models of pathological myocardial growth. In addition to reduction of LV mass, statins were shown to reduce myocardial fibrosis, increase capillary density network and attenuate electrical instability of the hypertrophied heart. Most importantly, statins improved systolic and diastolic LV function and even decreased mortality. The inhibition of hypertrophic growth was only partly achieved by reduction of haemodynamic overload. Direct mechanisms, such as inhibition of neurohumoral activation in the myocardial tissue, attenuated production of growth factors and markers of inflammation and reduction of oxidative stress also seem to participate. The protective effect of statins was associated with the inhibition of expression and activation of small guanosintriphosphate-binding proteins such as Ras and Rho, which control the intensity of oxidative stress, the production and availability of nitric oxide, and the expression of genes involved in myocardial growth. In addition to reduction of LV mass, statins may also improve the prognosis of LVH independently of their lipid-lowering effect.

Are statins effective for simultaneously treating dyslipidemias and hypertension?

3-Hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase inhibitors (statins) are unequivocally useful for lowering cholesterol levels in patients with dyslipidemias characterized by elevations in total and/or low-density lipoprotein cholesterol. The beneficial effects of statins to lower serum cholesterol translate into significant reductions in cardiovascular morbidity and mortality. In addition to lowering cholesterol levels, statins have other biological effects relevant to cardiovascular homeostasis including anti-inflammatory actions and downregulation of angiotensin type 1 receptor expression that contribute to improvements in endothelial function and arterial compliance. Since endothelial dysfunction and reduced arterial compliance are important pathophysiological determinants of essential hypertension, these actions of statins raise the possibility that statin therapy may be useful for simultaneously treating dyslipidemias and hypertension. However, it has been unclear whether statins are effective in lowering blood pressure. This controversy stems from a variety of methodological limitations including inadequate sample size, confounding effects of antihypertensive drugs, differences in blood pressure measurement techniques, and differences in patient populations. However, based on published results from both small clinical studies and large randomized clinical trials, statins modestly lower blood pressure in patients with high, but not normal, blood pressure, regardless of cholesterol level.

Do Statins Reduce Blood Pressure?

A meta-analysis was performed of the effect of 3hydroxy3methylglutaryl-coenzyme A reductase inhibitors (statins) on blood pressure in humans including the randomized, controlled trials of statin therapy (20 trials and 828 patients) in which concomitant antihypertensive treatment (if any) remained unchanged throughout the study. A total of 291 and 272 patients were given a statin or placebo, respectively, in parallel group trials, whereas 265 took part in crossover trials receiving a statin and placebo (or probucol, in 1 trial). Systolic blood pressure was significantly lower in patients on statin than in those on placebo or control hypolipidemic drug (mean difference: -1.9 mm Hg; 95% CI: -3.8 to -0.1). The effect was greater when the analysis was restricted to studies with a baseline systolic blood pressure >130 mm Hg (Delta systolic blood pressure: -4.0; 95% CI: -5.8 to -2.2 mm Hg). There was a trend for lower diastolic blood pressure in patients receiving statin therapy compared with control: -0.9 mm Hg (95% CI: -2.0 to 0.2) overall and -1.2 mm Hg (95% CI: -2.6 to 0.1) in studies with a baseline diastolic blood pressure >80 mm Hg. In general, the higher the baseline blood pressure, the greater the effect of statins on blood pressure (P=0.066 for systolic blood pressure and P=0.023 for diastolic blood pressure). The blood pressure response to statins was unrelated to age, changes in serum cholesterol, or length of the trial. In conclusion, statin therapy has a relatively small but statistically significant and clinically meaningful effect on blood pressure.

Ongoing clinical trials of the pleiotropic effects of statins

BACKGROUND

The multiple effects (ie, pleiotropic effects of statins) have received increasing recognition and may have clinical applicability across a broad range of cardiovascular and noncardiovascular conditions.

OBJECTIVE

To determine the relevance and significance of ongoing clinical trials of the pleiotropic effects of statins, focusing on nonlipid effects.

METHOD

Ongoing trials were identified through personal communication, reports presented at scientific meetings (2000-2004), and queries made to AstraZeneca, Bristol-Myers Squibb Co, Merck & Co, Novartis, and Pfizer, manufacturers of the currently marketed statins. Published trials and other source material were identified through electronic searches on MEDLINE (1990-2003), abstract books, and references identified from bibliographies of pertinent articles. Eligible studies were the clinical trials of statins currently under way in which primary or secondary outcomes included the statins' nonlipid (ie, pleiotropic) effect(s). Data were extracted and trial quality was assessed by the authors.

RESULTS

Of the 22 ongoing trials of the nonlipid effects of statins identified, 10 assessed inflammatory markers and plaque stabilization, 4 assessed oxidized low density lipoprotein/vascular oxidant stress, 3 assessed end-stage renal disease, 3 assessed fibrinogen/viscosity, 2 assessed endothelial function, 2 assessed acute coronary syndrome, 2 assessed aortic stenosis progression, and 1 each assessed hypertension, osteoporosis, ischemic burden, Alzheimer's disease, multiple sclerosis, and stroke (outcomes often overlapped).

CONCLUSION

Given the excellent safety and tolerability of statins as a class, full exploration of their pleiotropic effects has the potential to provide additional benefits to many patients.

Statins in heart failure. Beyond the lipid lowering effect

Statins, the most widely prescribed medications in patients with hyperlipidemia and coronary heart disease, have a number of pleiotropic actions beyond cholesterol lowering. They improve endothelial function, they have antioxidant and anti-inflammatory effects, they regulate neovascularization and have immunomodulatory activities. Experimental evidence suggests that statins may be beneficial in heart failure as they can inhibit myocardial hypertrophy, reduce cardiomyocyte loss by apoptosis, reduce oxidative stress and restore neurohormonal imbalance. Furthermore small randomised clinical trials showed that short term statin administration may improve key pathophysiological aspects of this syndrome. Finally retrospective analyses of large statin trials imply a long term profit on clinical outcome in this group of patients. These results however need to be reviewed with caution as certain studies have demonstrated that low serum cholesterol is associated with worse prognosis in HF and that ubiquinone levels, a micronutrient with antioxidant actions, reduces significantly following statin administration. Large prospective randomised controlled trials are needed to confirm the beneficial effect of statins on cardiovascular outcome in HF patients and further elucidate the contributing mechanisms. Finally the statin dose and the interaction with co-administered drugs need to be studied.

Lipid-lowering therapy with statins, a new approach to antiarrhythmic therapy

Inhibitors of 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase (statins) are the most effective and best-tolerated drugs to treat elevated levels of low-density lipoprotein cholesterol (LDL-C). In addition, they exhibit other effects unrelated to their lipid lowering effects (pleiotropic actions). In recent years, experimental and clinical evidence demonstrates that statins exert antiarrhythmic properties, reducing the recurrences of supraventricular and life-threatening ventricular arrhythmias both in patients with and without coronary artery disease (CAD). Thus, statins may constitute a novel therapeutic approach to cardiac arrhythmias. This article reviews the antiarrhythmic properties of statins as well as the possible mechanisms involved, including the lowering of LDL-C levels, the improvement of endothelial dysfunction and autonomic function, the stabilization of the atherosclerotic plaques, the antioxidant, antiinflammatory, antithrombotic and cardioprotective properties and the modulation of transmembrane ion fluxes.

Oxidative biomarkers in the diagnosis and prognosis of cardiovascular disease

Oxidative damage to lipids and proteins is an important component of atherosclerotic cardiovascular disease (CVD). Studies of oxidation-related molecules are helping to define atherosclerotic mechanisms, and measurements of circulating levels of specific oxidant compounds may improve cardiovascular risk assessment. The present article reviews accumulating data of selected oxidative biomarkers that support their role in providing diagnostic and/or prognostic information. For example, plasma levels of the enzyme myeloperoxidase, which generates the strong oxidizing agent hypochlorous acid, have been found to be correlated with risk for myocardial infarction and endothelial dysfunction. Elevated levels of lipoprotein-associated phospholipase A(2) are associated with coronary artery disease (CAD) and stroke. Oxidized phospholipids play an important role in atherosclerosis. Recent studies measuring circulating levels of oxidized phospholipids have suggested a strong association with CAD, plaque disruption, and response to 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitor ("statin") therapy. Isoprostanes correlate strongly with cardiovascular risk factors, but their role in risk prediction is less well defined. Future studies are expected to clarify the role of oxidative biomarkers in the diagnosis and prognosis of CVD and to determine their value in specific clinical populations.

Effect of pravastatin on left ventricular mass in the two-kidney, one-clip hypertensive rats

We have demonstrated that myocardial ATP-sensitive potassium (KATP) channels are implicated in the development of cardiac hypertrophy in hyperlipidemic rabbits. We investigated the effect of pravastatin on development of ventricular hypertrophy in male normolipidemic Wistar rats with two-kidney, one-clip (2K1C) hypertension and whether the attenuated hypertrophic effect was via activation of KATPchannels. Twenty-four hours after the left renal artery was clipped, rats were treated with one of the following therapies for 8 wk: vehicle, nicorandil (an agonist of KATPchannels), pravastatin, glibenclamide (an antagonist of KATPchannels), hydralazine, nicorandil plus glibenclamide, or pravastatin plus glibenclamide. Systolic blood pressure, relative left ventricular (LV) weight, and cardiomyocyte sizes significantly increased in vehicle-treated 2K1C rats compared with those in sham-operated rats. Treatment with either nicorandil or pravastatin significantly attenuated LV hypertrophy/body weight compared with the vehicle, which was further confirmed by downregulation of LV atrial natriuretic peptide mRNA. Nicorandil-induced effects were abolished by administering glibenclamide. Similarly, pravastatin-induced beneficial effects were reversed by the addition of glibenclamide, implicating KATPchannels as the relevant target. A dissociation between the effects of blood pressure and cardiac structure was noted because pravastatin and hydralazine reduced arterial pressure similarly. These results suggest a crucial role of cardiac KATPchannel system in the development of ventricular hypertrophy in the 2K1C hypertensive rats. Pravastatin is endowed with cardiac antihypertrophic properties probably through activation of KATPchannels, independent of lipid and hemodynamic changes.

Association of gliclazide and left ventricular mass in type 2 diabetic patients

Diabetes is a state of increased oxidant stress and there is evidence that oxidation may play a role in the genesis of higher left ventricular mass. Gliclazide has been shown to possess free radical scavenging properties. We assessed whether gliclazide may have a beneficial effect on left ventricular mass via reducing 8-iso-prostaglandin F(2alpha) concentrations, a reliable marker of oxidant injury. A total of 41 patients were randomized into two groups. All patients had been taking glibenclamide for more than 3 months before being randomized to switch either an equipotent dose of gliclazide (n=21) or to continue on glibenclamide (n=20). Baseline characteristics were similar in both groups. At 6 months, gliclazide-treated patients showed a significant regression in left ventricular mass index compared with the glibenclamide-treated group (-16% versus 3%, P=0.003). Gliclazide patients had significantly lower plasma 8-iso-prostaglandin F(2alpha) compared with baseline (299+/-101 pg/ml versus 400+/-112 pg/ml, P=0.001) and the glibenclamide-treated patients (299+/-101 pg/ml versus 388+/-114 pg/ml, P=0.01) after 6-month therapy. The magnitude of left ventricular mass index regression correlated univariately with the magnitude of inhibition of 8-iso-prostaglandin F(2alpha) formation (r=0.74, P<0.0001). Multivariate analysis revealed that regression of left ventricular mass index significantly correlated with the changes of 8-iso-prostaglandin F(2alpha) (P<0.0001, adjusted R(2)=0.55). Our findings demonstrated for the first time that in addition to its primary hypoglycemia, gliclazide may have an additional effect on reducing left ventricular mass, possibly through attenuation of free radical formation.

Effects of pravastatin on ventricular remodeling by activation of myocardial KATP channels in infarcted rats: role of 70-kDa S6 kinase

Reactive cardiomyocyte hypertrophy after myocardial infarction is an important risk factor for arrhythmias. Myocardial ATP-sensitive potassium (K(ATP)) channels have been implicated in attenuating cardiac hypertrophy by inhibition of 70-kDa S6 kinase. We investigated the effect of pravastatin on ventricular hypertrophy during remodeling after myocardial infarction and whether the attenuated hypertrophic effect was via activation of myocardial K(ATP) channels. Twenty-four hours after ligation of the anterior descending artery, male Wistar rats were randomized to either vehicle, nicorandil (an agonist of K(ATP) channels), pravastatin, glibenclamide (an antagonist of K(ATP) channels), or a combination of nicorandil and glibenclamide or pravastatin and glibenclamide for 4 weeks. Infarct size and mortality were similar among the infarcted groups. Cardiomyocyte sizes isolated by enzymatic dissociation after infarction significantly increased at the border zone in vehicle-treated infarcted rats compared with sham-operated rats. Rats in the nicorandil- and pravastatin-treated groups significantly attenuated cardiomyocyte hypertrophy, as compared with the vehicle-treated group. Arrhythmic scores during programmed stimulation mirrored those of cardiomyocyte hypertrophy. Increased 70-kDa S6 kinase mRNA expression in cardiac remodeling was confirmed by reverse transcription-polymerase chain reaction, consistent with the results of immunohistochemistry and Western blot for the phosphorylation of 70-kDa S6 kinase. Nicorandil-induced effects were abolished by administering glibenclamide. Similarly, the beneficial effects of pravastatin were abolished by administering glibenclamide, implicating K(ATP) channels as the relevant target. Activation of K(ATP) channels by pravastatin administration can attenuate ventricular remodeling through a S6 kinase-dependent pathway after infarction.

Additive effects of combined blockade of AT1receptor and HMG-CoA reductase on left ventricular remodeling in infarcted rats

Both angiotensin receptor antagonists and 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase inhibitors have been shown to attenuate cardiomyocyte hypertrophy after myocardial infarction. Whether combination treatment may be superior to either drug alone on cardiomyocyte hypertrophy remains unclear. After ligation of the left anterior descending artery, rats were randomized to both, one, or neither of the angiotensin receptor antagonists olmesartan (0.01, 0.1, 1, and 2 mg·kg−1·day−1) and HMG-CoA reductase inhibitor pravastatin (5 mg·kg−1·day−1) for 4 wk. Each drug, when given alone, decreased cardiomyocyte sizes isolated by enzymatic dissociation at the border zone when compared with vehicles. However, compared with either drug alone, combined olmesartan and pravastatin prevent cardiomyocyte hypertrophy to a larger extent, which was further confirmed by downregulation of the left ventricular atrial natriuretic peptide mRNA. The myocardial endothelin-1 levels at the border zone were 6.5-fold higher ( P <0.0001) in the vehicle group compared with the sham group, which can be inhibited after pravastatin administration. Combination treatment significantly attenuated cardiomyocyte hypertrophy in a dose-dependent manner, although tissue endothelin-1 levels remained stable in combination groups of different olmesartan doses. Measurements of the arrhythmic score mirrored those of cardiomyocyte hypertrophy. Dual therapy with pravastatin and olmesartan, which produced an additive reduction in cardiomyocyte hypertrophy and cardiac fibrosis after myocardial infarction through different mechanisms, decreases the propensity of the heart to arrhythmogenesis. Pravastatin administration provided favorable ventricular remodeling, probably through decreased tissue endothelin-1 level. In contrast, olmesartan-related attenuated cardiomyocyte hypertrophy is independent of endothelin-1 pathway.

Statins and myocardial hypertrophy

Cardiac hypertrophy is a physiological adaptive response by the heart to pressure overload. However, after prolonged periods, this initial adaptive response becomes maladaptive, leading to increased mortality and morbidity from heart failure. Recently, 3-hydroxyl-3-methylglutaryl coenzyme A (HMG-CoA) reductase inhibitors, or statins, have been shown to inhibit cardiac hypertrophy by cholesterol-independent mechanisms. Statins block the isoprenylation and activation of members of the Rho guanosine triphosphatase (GTPase) family, such as RhoA and Rac1. Since Rac1 is a requisite component of reduced nicotinamide adenine dinucleotide phosphate (NADPH) oxidase, which is a major source of reactive oxygen species (ROS) in cardiovascular cells, the ability of statins to inhibit Rac1-mediated oxidative stress makes an important contribution to their inhibitory effects on cardiac hypertrophy.

Prevalence and determinants of electrocardiographic left ventricular hypertrophy among a multiethnic population of postmenopausal women (The Women's Health Initiative)

Our objectives were to determine the prevalence and factors related to left ventricular hypertrophy (LVH) among older women for commonly used electrocardiographic criteria. LVH is a potent risk factor for cardiovascular disease, especially among women. However, its value has been limited, in part, by the use of different electrocardiographic criteria and the lack of a clearly defined standard for the general population. A total of 3,613 eligible women, aged 50 to 79 years, underwent medical history, physical measurements, and biochemical determinations and had behavioral factors recorded at baseline. Three LVH indexes were derived from computer measurement of the electrocardiogram: hypertrophied left ventricular mass > or =171.04 g (HLVM); Cornell voltage > or =2,200 microV; and Minnesota Code items. The prevalence of LVH ranged from <1% to 13% when stratified by age, ethnicity, and scoring technique. Baseline traits differed significantly for those meeting the LVH criteria. Predictors (p <0.01) of HLVM were age (odds ratio 0.66), height (odds ratio 1.47), waist/hip ratio (odds ratio 1.30), systolic blood pressure (odds ratio 1.18); low-density lipoprotein cholesterol (odds ratio 0.97), log insulin (odds ratio 2.10), dietary kilocalories (odds ratio 1.16), weekly energy expenditure (odds ratio 0.53), hypertension (odds ratio 1.61), current estrogen use (odds ratio 0.60), and current smoker (odds ratio 0.47). The presence of the metabolic syndrome was related to all LVH indexes, with odds ratios of 4.95, 2.24, and 2.35, respectively, for HLVM, Cornell voltage, and Minnesota Code. In conclusion, the prevalence of LVH varied by ethnicity and the electrocardiographic index used. However, the baseline traits, especially the factors associated with the metabolic syndrome, were consistently and strongly related to all LVH indexes, particularly HLVM. Intervention on these factors may provide strategies for reducing LVH, a strong independent risk factor for cardiovascular morbidity and mortality among women.

Statins and the myocardium

Cardiac hypertrophy and heart failure are leading causes of morbidity and mortality worldwide. The 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitors, or statins, have been shown to inhibit cardiac hypertrophy and improve symptoms of heart failure by cholesterol-independent mechanisms. Statins block the isoprenylation and function of members of the Rho GTPase family, such as Rac1 and RhoA. Because Rac1 is a requisite component of NADPH oxidase, which is a major source of reactive oxygen species in cardiovascular cells, the ability of statins to inhibit Rac1-mediated oxidative stress contributes importantly to their inhibitory effects on cardiac hypertrophy. Furthermore, inhibition of RhoA by statins leads to the activation of protein kinase B/Akt and upregulation of Type 3 nitric oxide synthase in the endothelium and the heart. This activation and upregulation results in increased angiogenesis and myocardial perfusion, decreased myocardial apoptosis, and improvement in endothelial and cardiac function. Because these effects of statins occur independent of cholesterol lowering, statins may have therapeutic benefits in nonhyperlipidemic patients with cardiac hypertrophy and heart failure.

Effect of estrogen on coronary vasoconstriction in patients undergoing coronary angioplasty

BACKGROUND

Estrogen has an antioxidant potential which may contribute to its cardioprotective effect. We sought to determine whether estrogen administration can affect coronary vasomotor tone in patients after angioplasty by reducing 8-iso-prostaglandin (PG) F(2alpha) concentrations, a bioactive product of lipid peroxidation.

METHODS

The study was designed to prospectively investigate 30 consecutive patients scheduled for elective coronary angioplasty. Patients were randomized into two groups according to whether they did not (group 1, n = 15) or did have (group 2, n = 15) intracoronary (i.c.) treatment with estrogen prior to coronary angioplasty.

RESULTS

There were no significant differences of collateral circulation assessed by intracoronary Doppler flow velocity during balloon inflations between the study groups. The diameters of the coronary artery at the dilated and distal segments were significantly reduced 15 min after dilation compared with those immediately after dilation in group 1 (both P < 0.0001). The vasoconstriction was significantly blunted in group 2. The 8-iso-PGF(2alpha) levels in plasma from the coronary sinus rose significantly from 194 +/- 45 to 390 +/- 97 pg/ml (P < 0.0001, 95% confidence intervals = 142-249 pg/ml) 15 min after angioplasty in group 1, which was attenuated after administering estrogen. Significant correlation was found between the changes of coronary vasomotion of the dilated segment and 8-iso-PGF(2alpha) levels in group 1 (r = 0.73, P = 0.002).

CONCLUSIONS

8-iso-PGF(2alpha) is released into the coronary circulation during angioplasty, and this vasoactive substance may contribute to the occurrence of vasoconstriction. Estrogen administration attenuated vasoconstriction by reducing the 8-iso-PGF(2alpha) levels. This finding may provide a new strategy to treat coronary vasoconstriction after angioplasty.