Effects of pravastatin on left ventricular mass in patients with hyperlipidemia and essential hypertension

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.

Statins and Cardiomyocyte Metabolism, Friend or Foe?

Statins inhibit HMG-CoA reductase, the rate-limiting enzyme in cholesterol synthesis, and are the cornerstone of lipid-lowering treatment. They significantly reduce cardiovascular morbidity and mortality. However, musculoskeletal symptoms are observed in 7 to 29 percent of all users. The mechanism underlying these complaints has become increasingly clear, but less is known about the effect on cardiac muscle function. Here we discuss both adverse and beneficial effects of statins on the heart. Statins exert pleiotropic protective effects in the diseased heart that are independent of their cholesterol-lowering activity, including reduction in hypertrophy, fibrosis and infarct size. Adverse effects of statins seem to be associated with altered cardiomyocyte metabolism. In this review we explore the differences in the mechanism of action and potential side effects of statins in cardiac and skeletal muscle and how they present clinically. These insights may contribute to a more personalized treatment strategy.

Impact of medical therapy for cardiovascular disease on left ventricular diastolic properties and remodeling

Background

Left ventricular (LV) remodeling and diastolic properties are affected by both underlying cardiovascular disease/cardiovascular disease risk factors (CVDRFs) and corresponding medication therapy. However, these effects may not be apparent in patients with multiple CVDRFs. We evaluated the effect of medication classes on hemodynamics in a patient cohort with normal LV dimensions and systolic function.

Methods

In 38 participants (61 ± 7 years, 64 ± 9% LV ejection fraction) undergoing coronary angiography, LV pressure measurement and cardiac magnetic resonance imaging was performed. The effects of coronary artery disease (CAD), CVDRFs and their corresponding medication therapy on LV parameters were analyzed considering the number of CAD/CVDRFs and ‘adequacy’ of medication therapy to address each existing condition with specific indication-based medication classes.

Results

Of the patients studied, 68% had CAD, 87% had hypertension, 87% had dyslipidemia, and 45% had diabetes. Neither individual or total number of CAD/CVDRFs were associated with overall differences in LV diastolic parameters. However, those without (n = 20) and with (n = 18) ‘adequate’ medication therapy for underlying CAD/CVDRFs differed in values of LV end diastolic pressure (17 ± 4 vs. 11 ± 5 mm Hg, P < 0.001), wall stress (3.9 ± 1.6 vs. 2.2 ± 1.2 x1000 N/m², P < 0.001), pressure/volume ratio (0.13 ± 0.04 vs. 0.08 ± 0.03 mm Hg/ml, P < 0.01), and mass/volume ratio (0.77 ± 0.20 vs. 0.92 ± 0.24 g/ml, P < 0.05), but not in systolic blood pressure or LV mass index.

Conclusions

Our results suggest an association between the degree of LV diastolic impairment and LV remodeling with the intensity of treatment for CAD/CVDRFs. Comprehensive treatment of all identified CAD/CVDRFs may be an important factor for the preservation of diastolic function.

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.

The Degree of Albuminuria Is Related to Left Ventricular Hypertrophy in Hypertensive Diabetics and Is Associated with Abnormal Left Ventricular Filling: A Pilot Study

The association of albuminuria and left ventricular (LV) hypertrophy (LVH) in diabetics aggra vates the prognosis. The authors studied the relation between LVH and the degree of albu minuria in diabetics and investigated the relationship of albuminuria to LV filling. A comparison was made between 30 hypertensive diabetics, 10 of whom had microalbuminuria (MIC) and 20 had macroalbuminuria (MAC), and 18 diabetics who were normotensive and normalbuminuric (NOR). LV mass index (LVMI) and LV ejection fraction (LVEF) were measured during echocar diography. LV filling pattern at rest and at peak standardized isometric exercise (IME) using handgrip was assessed by measuring E/A (peak velocity of the early/atrial filling waves) of the transmitral flow during Doppler and echocardiography. Each patient underwent a stress ECG test. LVMI was higher in MAC (132.3 ±55.4) than in MIC (115.6 ±32.5) or NOR (90.0 ±31.8) (p<0.01). There were more patients in MAC with LVH (n = 13) and abnormal filling (n = 9 at rest and 16 with IME) than in MIC (LVH = 5, abnormal filling = 1 at rest and 10 during IME) or NOR (LVH = 3, abnormal filling = 1 at rest and 9 during IME) (p < 0.02). LVMI was not related to LVEF. Although blood pressure was not different between MAC and MIC groups, it was signif icantly higher than in the NOR group. This study suggests that a high degree of albuminuria in hypertensive diabetics is associated with greater value for LVMI and an increased incidence of LVH independent of blood pressure level or systolic LV function. LVH is associated with abnormal LV filling. The degree of albuminuria may predict LVMI and LVH, which are associated with abnormal LV filling. This association of abnormal LV filling with albuminuria in hypertensive diabetic patients may account for their high risk of cardiovascular events.

Chamber-specific differences in human cardiac fibroblast proliferation and responsiveness toward simvastatin

Fibroblasts, the most abundant cells in the heart, contribute to cardiac fibrosis, the substrate for the development of arrythmogenesis, and therefore are potential targets for preventing arrhythmic cardiac remodeling. A chamber-specific difference in the responsiveness of fibroblasts from the atria and ventricles toward cytokine and growth factors has been described in animal models, but it is unclear whether similar differences exist in human cardiac fibroblasts (HCFs) and whether drugs affect their proliferation differentially. Using cardiac fibroblasts from humans, differences between atrial and ventricular fibroblasts in serum-induced proliferation, DNA synthesis, cell cycle progression, cyclin gene expression, and their inhibition by simvastatin were determined. The serum-induced proliferation rate of human atrial fibroblasts was more than threefold greater than ventricular fibroblasts with faster DNA synthesis and higher mRNA levels of cyclin genes. Simvastatin predominantly decreased the rate of proliferation of atrial fibroblasts, with inhibition of cell cycle progression and an increase in the G0/G1 phase in atrial fibroblasts with a higher sensitivity toward inhibition compared with ventricular fibroblasts. The DNA synthesis and mRNA levels of cyclin A, D, and E were significantly reduced by simvastatin in atrial but not in ventricular fibroblasts. The inhibitory effect of simvastatin on atrial fibroblasts was abrogated by mevalonic acid (500 μM) that bypasses 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase inhibition. Chamber-specific differences exist in the human heart because atrial fibroblasts have a higher proliferative capacity and are more sensitive to simvastatin-mediated inhibition through HMG-CoA reductase pathway. This mechanism may be useful in selectively preventing excessive atrial fibrosis without inhibiting adaptive ventricular remodeling during cardiac injury.

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.

Prevention of cardiac hypertrophy by the use of a glycosphingolipid synthesis inhibitor in ApoE-/- mice

ApoE-/- mice fed a high fat and high cholesterol (HFHC) diet (20% fat and 1.25% cholesterol) from 12 weeks of age to 36 weeks revealed an age-dependent increase in the left ventricular mass (LV mass) and decline in fractional shortening (FS%), which worsened with HFHC diet. These traits are indicative of maladaptive pathological cardiac hypertrophy and dysfunction. This was accompanied by loading of glycosphingolipids and increased gene expression of ANP, BNP in myocardial tissue. Masson's trichrome staining revealed a significant increase in cardiomyocyte size and fibrosis. In contrast, treatment with 5 and 10 μM D-threo-1-phenyl-2-decanoylamino-3-morpholino-1-propanol (D-PDMP), an inhibitor of glucosylceramide synthase and lactosylceramide synthase, dose-dependently decreased the load of glycosphingolipids and preserved fractional shortening and maintained left ventricular mass to normal 12-week-old control levels over a 6 month treatment period. Our mechanistic studies showed that D-PDMP inhibited cardiac hypertrophy by inhibiting the phosphorylation of mitogen-activated protein kinase (MAPK). We propose that associating increased glycosphingolipid synthesis with cardiac hypertrophy could serve as a novel approach to prevent this phenotype in experimental animal models of diet -induced atherosclerotic heart disease.

Low-density lipoprotein-cholesterol-induced endothelial dysfunction and oxidative stress: the role of statins

SIGNIFICANCE

Cardiovascular diseases (CVD) represent a major public health burden. High low-density lipoprotein (LDL)-cholesterol is a recognized pathogenic factor for atherosclerosis, and its complications and statins represent the most potent and widely used therapeutic approach to prevent and control these disorders.

RECENT ADVANCES

A number of clinical and experimental studies concur to identify endothelial dysfunction as a primary step in the development of atherosclerosis, as well as a risk factor for subsequent clinical events. Oxidant stress resulting from chronic elevation of plasma LDL-cholesterol (LDL-chol) is a major contributor to both endothelial dysfunction and its complications, for example, through alterations of endothelial nitric oxide signaling.

CRITICAL ISSUES

Statin treatment reduces morbidity and mortality of CVD, but increasing evidence questions that this is exclusively through reduction of plasma LDL-chol. The identification of ancillary effects on (cardio)vascular biology, for example, through their modulation of oxidative stress, will not only increase our understanding of their mechanisms of action, with a potential broadening of their indication(s), but also lead to the identification of new molecular targets for future therapeutic developments in CVD.

FUTURE DIRECTIONS

Further characterization of molecular pathways targeted by statins, for example, not directly mediated by changes in plasma lipid concentrations, should enable a more comprehensive approach to the pathogenesis of (cardio)vascular disease, including, for example, epigenetic regulation and fine tuning of cell metabolism.

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.

Statins for the primary prevention of cardiovascular disease

BACKGROUND

Reducing high blood cholesterol, a risk factor for cardiovascular disease (CVD) events in people with and without a past history of CVD is an important goal of pharmacotherapy. Statins are the first-choice agents. Previous reviews of the effects of statins have highlighted their benefits in people with CVD. The case for primary prevention was uncertain when the last version of this review was published (2011) and in light of new data an update of this review is required.

OBJECTIVES

To assess the effects, both harms and benefits, of statins in people with no history of CVD.

SEARCH METHODS

To avoid duplication of effort, we checked reference lists of previous systematic reviews. The searches conducted in 2007 were updated in January 2012. We searched the Cochrane Central Register of Controlled Trials (CENTRAL) in The Cochrane Library (2022, Issue 4), MEDLINE OVID (1950 to December Week 4 2011) and EMBASE OVID (1980 to 2012 Week 1).There were no language restrictions.

SELECTION CRITERIA

We included randomised controlled trials of statins versus placebo or usual care control with minimum treatment duration of one year and follow-up of six months, in adults with no restrictions on total, low density lipoprotein (LDL) or high density lipoprotein (HDL) cholesterol levels, and where 10% or less had a history of CVD.

DATA COLLECTION AND ANALYSIS

Two review authors independently selected studies for inclusion and extracted data. Outcomes included all-cause mortality, fatal and non-fatal CHD, CVD and stroke events, combined endpoints (fatal and non-fatal CHD, CVD and stroke events), revascularisation, change in total and LDL cholesterol concentrations, adverse events, quality of life and costs. Odds ratios (OR) and risk ratios (RR) were calculated for dichotomous data, and for continuous data, pooled mean differences (MD) (with 95% confidence intervals (CI)) were calculated. We contacted trial authors to obtain missing data.

MAIN RESULTS

The latest search found four new trials and updated follow-up data on three trials included in the original review. Eighteen randomised control trials (19 trial arms; 56,934 participants) were included. Fourteen trials recruited patients with specific conditions (raised lipids, diabetes, hypertension, microalbuminuria). All-cause mortality was reduced by statins (OR 0.86, 95% CI 0.79 to 0.94); as was combined fatal and non-fatal CVD RR 0.75 (95% CI 0.70 to 0.81), combined fatal and non-fatal CHD events RR 0.73 (95% CI 0.67 to 0.80) and combined fatal and non-fatal stroke (RR 0.78, 95% CI 0.68 to 0.89). Reduction of revascularisation rates (RR 0.62, 95% CI 0.54 to 0.72) was also seen. Total cholesterol and LDL cholesterol were reduced in all trials but there was evidence of heterogeneity of effects. There was no evidence of any serious harm caused by statin prescription. Evidence available to date showed that primary prevention with statins is likely to be cost-effective and may improve patient quality of life. Recent findings from the Cholesterol Treatment Trialists study using individual patient data meta-analysis indicate that these benefits are similar in people at lower (< 1% per year) risk of a major cardiovascular event.

AUTHORS' CONCLUSIONS

Reductions in all-cause mortality, major vascular events and revascularisations were found with no excess of adverse events among people without evidence of CVD treated with statins.

Central versus peripheral cardiovascular risk in metabolic syndrome

Individuals with metabolic syndrome (MetS; i.e., three of five of the following risk factors (RFs): elevated blood pressure, waist circumference, triglycerides, blood glucose, or reduced HDL) are thought to be prone to serious cardiovascular disease and there is debate as to whether the disease begins in the peripheral vasculature or centrally. This study investigates hemodynamics, cardiac function/morphology, and mechanical properties of the central (heart, carotid artery) or peripheral [total peripheral resistance (TPR), forearm vascular bed] vasculature in individuals without (1–2 RFs: n = 28), or with (≥3 RFs: n = 46) MetS. After adjustments for statin and blood pressure medication use, those with MetS had lower mitral valve E/A ratios (<3 RFs: 1.24 ± 0.07; ≥3 RFs: 1.01 ± 0.04; P = 0.025), and higher TPR index (<3 RFs: 48 ± 2 mmHg/L/min/m²; ≥3 RFs: 53 ± 2 mmHg/L/min/m²; P = 0.04). There were no differences in heart size, carotid artery measurements, cardiovagal baroreflex, pulse-wave velocity, stroke volume index, or cardiac output index due to MetS after adjustments for statin and blood pressure medication use. The use of statins was associated with increased inertia in the brachial vascular bed, increased HbA1c and decreased LDL cholesterol. The independent use of anti-hypertensive medication was associated with decreased predicted VO2max, triglycerides, diastolic blood pressure, interventricular septum thickness, calculated left ventricle mass, left ventricle posterior wall thickness, and left ventricle pre-ejection period, but increased carotid stiffness, HDL cholesterol, and heart rate. These data imply that both a central cardiac effect and a peripheral effect of vascular resistance are expressed in MetS. These data also indicate that variance in between-group responses due to pharmacological treatments are important factors to consider in studying cardiovascular changes in these individuals.

Statins in non-ischaemic cardiomyopathy: an update on our current clinical and pathophysiological understanding

Statins are a cornerstone in reducing cardiovascular events. Studies show that statins are beneficial even in patients with normal or low cholesterol levels, indicating pleiotropic mechanisms of therapeutic benefit apart from their antihyperlipidemic effect. Non-randomised, observational and retrospective studies suggest that statins are associated with better outcomes in patients with heart failure (HF) of both ischaemic and non-ischaemic aetiologies. While cholesterol reduction and plaque stabilisation likely play a role in reducing cardiovascular events in ischaemic HF patients, the mechanisms underlying the benefit in non-ischaemic HF patients is less clear. This review suggests the pleiotropic effects of statin therapy can beneficially alter the pathophysiological mechanisms underlying the clinical benefit observed in non-ischaemic HF patients.

Statins and myocardial remodelling: cell and molecular pathways

The advent of statins has revolutionised the treatment of patients with raised plasma cholesterol and increased cardiovascular risk. However, the beneficial effects of this class of drugs are far greater than would be expected from lowering of cholesterol alone, and they appear to offer cardiovascular protection at multiple levels, primarily as a result of their pleiotropic activity. Indeed, their favourable effects on the heart seem to be mediated in part through reduced prenylation and subsequent inhibition of small GTPases, particularly those of the Rho family. Such statin-mediated effects are manifested by reduced onset of heart failure and improvements in cardiac dysfunction and remodelling in heart failure patients. Experimental studies have shown that statins mediate their effects on the two major resident cell types of the heart--cardiomyocytes and cardiac fibroblasts--and thus facilitate improvement of adverse remodelling of ischaemic or non-ischaemic aetiology. This review examines evidence for the cellular effects of statins in the heart, and discusses the underlying molecular mechanisms at the level of the cardiomyocyte (hypertrophy, cell death and contractile function) and the cardiac fibroblast (differentiation, proliferation, migration and extracellular matrix synthesis). The prospects for future therapies and ongoing clinical trials are also summarised.

Statins for the primary prevention of cardiovascular disease

BACKGROUND

Reducing high blood cholesterol, a risk factor for cardiovascular disease (CVD) events in people with and without a past history of coronary heart disease (CHD) is an important goal of pharmacotherapy. Statins are the first-choice agents. Previous reviews of the effects of statins have highlighted their benefits in people with coronary artery disease. The case for primary prevention, however, is less clear.

OBJECTIVES

To assess the effects, both harms and benefits, of statins in people with no history of CVD.

SEARCH STRATEGY

To avoid duplication of effort, we checked reference lists of previous systematic reviews. We searched the Cochrane Central Register of Controlled Trials (Issue 1, 2007), MEDLINE (2001 to March 2007) and EMBASE (2003 to March 2007). There were no language restrictions.

SELECTION CRITERIA

Randomised controlled trials of statins with minimum duration of one year and follow-up of six months, in adults with no restrictions on their total low density lipoprotein (LDL) or high density lipoprotein (HDL) cholesterol levels, and where 10% or less had a history of CVD, were included.

DATA COLLECTION AND ANALYSIS

Two authors independently selected studies for inclusion and extracted data. Outcomes included all cause mortality, fatal and non-fatal CHD, CVD and stroke events, combined endpoints (fatal and non-fatal CHD, CVD and stroke events), change in blood total cholesterol concentration, revascularisation, adverse events, quality of life and costs. Relative risk (RR) was calculated for dichotomous data, and for continuous data pooled weighted mean differences (with 95% confidence intervals) were calculated.

MAIN RESULTS

Fourteen randomised control trials (16 trial arms; 34,272 participants) were included. Eleven trials recruited patients with specific conditions (raised lipids, diabetes, hypertension, microalbuminuria). All-cause mortality was reduced by statins (RR 0.83, 95% CI 0.73 to 0.95) as was combined fatal and non-fatal CVD endpoints (RR 0.70, 95% CI 0.61 to 0.79). Benefits were also seen in the reduction of revascularisation rates (RR 0.66, 95% CI 0.53 to 0.83). Total cholesterol and LDL cholesterol were reduced in all trials but there was evidence of heterogeneity of effects. There was no clear evidence of any significant harm caused by statin prescription or of effects on patient quality of life.

AUTHORS' CONCLUSIONS

Although reductions in all-cause mortality, composite endpoints and revascularisations were found with no excess of adverse events, there was evidence of selective reporting of outcomes, failure to report adverse events and inclusion of people with cardiovascular disease. Only limited evidence showed that primary prevention with statins may be cost effective and improve patient quality of life. Caution should be taken in prescribing statins for primary prevention among people at low cardiovascular risk.

Statins Do Not Reduce Atrial Fibrillation After Cardiac Valvular Surgery: A Single Centre Observational Study

INTRODUCTION: Statins may theoretically reduce postoperative atrial fibrillation (AF) in patients after cardiac valvular surgery due to preservation of endothelial function and anti-ischaemic, anti-inflammatory and anti-remodelling effects. METHODS: Two hundred seventy-two patients who underwent cardiac workup and subsequently cardiac valvular surgery without AF and concomitant coronary artery bypass grafting (CABG) at our hospital were selected. Preoperative drug use and postoperative AF were recorded. AF was defined as any episode of AF longer than 10 s. In addition, results from echocardiography and blood samples were retrieved. RESULTS: BASELINE CHARACTERISTICS WERE AS FOLLOWS: mean age was 65 ± 11 years, 142 (52%) patients were male, 189 (70%) had undergone aortic valve surgery and the mean left ventricular ejection fraction was 57 ± 12%. Statins were used by 79 patients (29%). Statin users, more often, had a prior percutaneous coronary intervention (25% vs 9%, p < 0.001) or CABG (24% vs 4%, p < 0.001), diabetes mellitus (22% vs 5%, p < 0.001) and more often used β-blockers (51% vs 24%, p < 0.001). Patients in the non-statin group more often had surgery on more than one valve (10% vs 3%, p = 0.043) and had a higher cholesterol level (222 ± 48 vs 190 ± 43 mg/dl, p < 0.001). Postoperative AF occurred in 54% (43/79) of the patients with and in 55% (106/193) of the patients without statins (p = 0.941). There was also no difference in the timing of onset of AF or duration of hospital stay. CONCLUSION: In this observational study, statin use was not associated with a reduced incidence of AF in patients after cardiac valvular surgery.

Endothelial dysfunction is associated with left ventricular mass (assessed using MRI) in an adult population (MESA)

Brachial flow-mediated dilation (FMD) is a measure of endothelial nitric oxide bioavailability. Endothelial nitric oxide controls vascular tone and is likely to modify the ventricular muscle coupling mechanism. The association between left ventricular mass and FMD is not well understood. We assessed the association between left ventricular mass index (LVMI) and FMD in participants of the Multi-Ethnic Study of Atherosclerosis (MESA). MESA is a population-based study of 6814 adults free of clinical cardiovascular disease at baseline who were recruited from six US clinics. LVMI (left ventricular mass per body surface area) and FMD were measured in 2447 subjects. Linear regression analysis was used to evaluate the association. The subjects had a mean age of 61.2±9.9 years, 51.2% females with 34.3% Caucasians, 21.6% Chinese, 19.4% African Americans and 24.7% Hispanics. The mean body mass index (BMI) was 27.4±4.8 kg m⁻², 9.4% had diabetes, 11% were current smokers and 38% hypertensives. The mean±s.d. LVMI was 78.1±15.9 g m⁻² and mean±s.d. FMD was 4.4%±2.8%. In univariate analysis, LVMI was inversely correlated with FMD (r= -0.20, P<0.0001). In the multivariable analysis, LVMI was associated with FMD (β coefficient (se) = -0.50 (0.11), P<0.001 (0.5 g m⁻² reduction in LVMI per 1% increase in FMD)) after adjusting for age, gender, race/ethnicity, systolic blood pressure, diabetes mellitus, smoking, weight, statin use, antihypertensive medication use, high-density lipoprotein (HDL) and low-density lipoprotein (LDL) cholesterol. The association between brachial flow mediated dilation and LVMI maybe independent of traditional CV risk factors in population based adults.

Additive beneficial effects of amlodipine and atorvastatin in reversing advanced cardiac hypertrophy in elderly spontaneously hypertensive rats

1. Additive beneficial effects on cardiovascular disease have been reported for amlodipine and atorvastatin. However, it is still unclear whether the combination of amlodipine and atorvastatin has additive beneficial effects on the regression of advanced cardiac hypertrophy in hypertension. In the present study, the effects of the drug combination on advanced cardiac hypertrophy were investigated in elderly spontaneously hypertensive rats (SHR). 2. Elderly SHR (36 weeks old) were randomly allocated into four groups of 12: (i) a vehicle-treated control group; (ii) an amlodipine (10 mg/kg per day)-treated group; (iii) an atorvastatin (10 mg/kg per day)-treated group; and (iv) a group treated with a combination of amlodipine and atorvastatin (both at 10 mg/kg per day). Drugs were administered by oral gavage every morning for a period of 12 weeks before hearts were harvested for analysis. 3. Combined administration of amlodipine and atorvastatin significantly suppressed cardiomyocyte hypertrophy, interstitial fibrosis and upregulation of hypertrophic and profibrotic genes, and also improved left ventricular diastolic dysfunction to a greater extent than did amlodipine monotherapy. Further beneficial effects of combination therapy on advanced cardiac hypertrophy were associated with a greater reduction of NADPH oxidase-mediated increases in cardiac reactive oxygen species (ROS), rather than decreased blood pressure and serum cholesterol levels. 4. To elucidate the underlying molecular mechanisms, we examined cardiovascular NADPH oxidase subunits and found that amlodipine clearly attenuated the expression of p47(phox) and p40(phox) and slightly but significantly reduced p22(phox) and Rac-1 levels in heart tissue. Combination treatment with amlodipine plus atorvastatin led to a further reduction in p22(phox), p47(phox) and Rac-1 protein levels compared with amlodipine alone. 5. In conclusion, combined amlodipine and atorvastatin treatment has a greater beneficial effect on advanced cardiac hypertrophy compared with amlodipine monotherapy. The benefits are likely to be related to the additive effects of the drugs on the suppression of NADPH oxidase-mediated ROS generation.

Management of hypertension in patients with left ventricular hypertrophy

Left ventricular hypertrophy (LVH) is a cardinal manifestation of organ damage in patients with arterial hypertension. Identifying LVH is a fundamental step in evaluating hypertensive patients, because clinical and epidemiologic studies have shown this condition has a strong independent adverse prognostic significance. LVH is an integrated marker of cardiovascular risk, reflecting hypertension's hemodynamic and nonhemodynamic effects on the heart. Reversing LVH is an intermediate goal of antihypertensive therapy. Pharmacologic strategies to reverse LVH should be based on combining two or more drugs: a renin-angiotensin system blocker (ie, angiotensin-converting enzyme inhibitor or angiotensin receptor antagonist), and a calcium antagonist or low-dose diuretic. Successful therapeutic plans should also include nonpharmacologic interventions to promote LVH regression.

High-Density Lipoprotein Cholesterol and Left Ventricular Mass Index in Peritoneal Dialysis

Objective

The prevalence of left ventricular hypertrophy (LVH) reaches 75% in patients with end-stage renal disease. In patients on peritoneal dialysis (PD), some factors, such as hypertension, volume overload, serum albumin, and residual renal function, have been reported to be related to LVH. Dyslipidemia often occurs in PD but it remains unclear whether dyslipidemia is related to LVH. We investigated the relationship between clinical parameters, including lipid profile, and left ventricular mass index (LVMI).

Methods

In this cross-sectional study, 34 patients undergoing PD for more than 1 year without combined therapy with hemodialysis were included. We recorded the patients’ clinical data and related those parameters with LVMI as evaluated by echocardiography.

Results

The patients included 23 males and 11 females (age 62.2 ± 12.1 years, duration on PD 31.6 ± 15.6 months). Mean LVMI was 142 ± 37 g/m2. In univariate analysis, urine volume ( r = -0.493, p = 0.003), total cholesterol ( r = -0.418, p = 0.01), high-density lipoprotein cholesterol (HDL-C; r = -0.374, p = 0.02), and human atrial natriuretic peptide (hANP; r = 0.600, p < 0.001) significantly correlated with LVMI. Stepwise multiple regression analysis showed that hANP (β= 0.524, p = 0.001) and HDL-C (β= -0.422, p = 0.007) were independently associated with LVMI ( r2 = 0.32).

Conclusion

Strict volume control and salt restriction is essential for prevention of LVH. The role of HDL-C in the development of LVH in PD patients remains to be determined.

HMG CoA reductase inhibition and left ventricular mass in hypertrophic cardiomyopathy: a randomized placebo-controlled pilot study

BACKGROUND

Statins reduce cardiomyocyte hypertrophy in animal models of hypertrophic cardiomyopathy, aortic banding and heart failure after myocardial infarction. We investigated the effect of the hydroxymethylglutaryl coenzyme A reductase inhibitor atorvastatin on left ventricular (LV) mass in patients with hypertrophic cardiomyopathy in a randomized placebo-controlled double-blind pilot study.

MATERIALS AND METHODS

Patients with hypertrophic cardiomyopathy were randomized to be treated once daily by atorvastatin 80 mg or placebo for nine months. LV mass was assessed by serial cardiac magnetic resonance imaging. LV systolic and diastolic function was determined by echocardiography. Markers of collagen metabolism and inflammation were also assessed.

RESULTS

Out of 78 screened patients with hypertrophic cardiomyopathy 28 (2 x 14) patients were eligible for randomization. Eleven patients in each group completed the study with cardiac magnetic resonance imaging assessments meeting the evaluation standards at baseline and at follow-up. Low-density lipoprotein cholesterol levels in the atorvastatin group decreased from 3.24 +/- 1.14 mmol L(-1) (125 +/- 44 mg dL(-1)) at baseline to 1.37 +/- 0.49 mmol L(-1) (53 +/- 19 mg dL(-1)) at follow-up (P < 0.001), but were unchanged in the placebo group. Baseline LV mass was 228 +/- 51 g in the placebo and 232 +/- 67 g in the atorvastatin group. The primary endpoint of change in LV mass from baseline to follow-up was 2 +/- 10% in the atorvastatin group versus 0 +/- 13% in the placebo group (P = NS). Parameters of LV volumes and diameters, systolic and diastolic function, and markers of collagen metabolism were also unchanged in both groups.

CONCLUSION

In patients with hypertrophic cardiomyopathy, this randomized placebo-controlled double-blind pilot study did not demonstrate an effect of 9-month treatment with atorvastatin 80 mg on LV mass reduction.

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.

Drug Insight: statins for nonischemic heart failure—evidence and potential mechanisms

While 3-hydroxy-3-methylglutaryl-coenzyme A reductase inhibitors, also known as statins, have a well-established in role in the treatment and prevention of ischemic coronary artery disease, their utility in the setting of heart failure (HF) and left ventricular (LV) dysfunction remains under investigation. Although a reduction in LDL is the major effect of statin therapy, pleiotropic effects have been demonstrated, which could be responsible for the reduction in morbidity and mortality seen with statin use in patients with HF. Patients with both ischemic and nonischemic HF have been shown to have improved survival with statin therapy, and patients receiving statin therapy are less likely to develop HF. Studies have demonstrated that statins reduce inflammation, improve endothelial function, decrease thrombogenicity, and improve LV and autonomic function. In this Review, we present the literature supporting the pleiotropic effects of statin therapy in patients with HF or LV dysfunction, and discuss the mechanisms by which statins might elicit the improvements in morbidity and mortality seen in these patients.

Molecular cardiology and genetics in the 21st century--a primer

The terminology and technology of molecular genetics and recombinant DNA have become an essential part of academic cardiology and will soon be applied at the bedside. The treatise includes a brief summary of the essentials of the DNA molecule, the more common techniques, and their application to genetics and molecular cardiology. It is written to be understood by physicians, scientists, and paramedical personnel who would not necessarily have a background in molecular biology. Inherent in the DNA molecule are three properties fundamental to all of the diagnostic and therapeutic applications, namely, the ability of DNA to separate into single strands, recombine (annealment or hybridization), and the presence of the negative charge enables DNA fragments to be separated easily by electrophoresis. Genetic linkage analysis of a family with an inherited disease enables one to identify the gene without knowing its protein product. Over 50 diseases in cardiology due to single-gene disorders have been identified and multiple mutations have been detected. The new therapeutic frontier will be stem cells and nuclear transfer. Identification of genes responsible for coronary artery disease made possible by genome-wide single nucleotide polymorphism (SNP) mapping techniques paves the way for personalized medicine.

Statins: another class of antihypertensive agents?

The assessment of global cardiovascular risk is an essential step in the management of atherosclerotic disease prevention. Among the risk factors to be addressed are hypertension and hyperlipidaemia; these commonly coexist. A neutral or lipid-friendly antihypertensive agent is probably useful in the presence of lipid abnormalities. Similarly, statins have been shown to decrease cardiovascular risk in hypertensive patients. There is also experimental and clinical evidence that statins have blood pressure (BP)-lowering effects. In this review, we discuss the beneficial effects of statins on BP, and provide an overview of the underlying pathophysiology. We also consider the evidence justifying the use of statins in the management of hypertensive patients.

Effect of statins and white blood cell count on mortality in patients with ischemic left ventricular dysfunction undergoing percutaneous coronary intervention

BACKGROUND

While morbidity and mortality were shown to be increased in the setting of an elevated white blood cell (WBC) count for patients with acute coronary syndrome, the impact of statin therapy on mortality for patients with an elevated WBC count is unknown in high-risk patients with coronary artery disease.

HYPOTHESIS

The goal of this study was to determine whether statin therapy improved survival in patients with elevated WBC count undergoing percutaneous coronary intervention (PCI) with preexisting left ventricular (LV) dysfunction, a population at high risk for adverse outcomes.

METHODS

We retrospectively evaluated consecutive patient procedures performed at our institution from 1996 through 1999. Patients had a technically adequate angiographic left ventriculogram with a calculated ejection fraction (EF) < or = 50%. Patients with prior coronary artery bypass graft were excluded. Mortality data were retrieved using the U.S. Social Security Death Index. Follow-up ranged from 3.5 to 6.5 years. Means are provided with +/- standard deviation, and p values < 0.05 were considered significant.

RESULTS

Of the study population of 238 patients (average EF 39 +/- 9.8%, mean age 57.5 +/- 12 years, 68% men) 61% underwent PCI for a recent myocardial infarction, 68% received stents, and 65% were discharged on statins. Mean WBC count was 9,000 +/- 3,100 cells/mm3, with 28% of patients having a WBC > or = 10,000 cells/mm3. During follow-up, 27% of our population died. Patients with a WBC > or = 10,000 had worse survival than patients with WBC < 10,000 (1-year survival: 86 vs. 96%, p < 0.05; 3-year survival: 79 vs. 89%, p < 0.05). Survival was significantly improved in patients on statin therapy regardless of WBC count, but the greatest benefit tended to be in patients with WBC > or = 10,000 (WBC > or = 10,000; odds ratio [OR] 5.14, 95% confidence interval [CI] 1.44-19.0, WBC < 10,000; OR 2.79,95% CI 1.13-7.1). Proportional hazard regression analysis demonstrated that both statin therapy and WBC count predicted mortality.

CONCLUSION

Patients undergoing PCI with LV dysfunction discharged on statins had improved survival regardless of WBC count, with a trend for greater improvement in patients with elevated WBC counts. In addition, WBC count predicts mortality in this high-risk population with LV dysfunction undergoing PCI.

In vitro inhibitory effects of atorvastatin on cardiac fibroblasts: implications for ventricular remodelling

1. Hydroxy-3-methylglutaryl coenzyme A (HMG CoA) reductase inhibitors (statins) reduce mortality after myocardial infarction (MI). Although this may be predominantly due to their known anti-ischaemic actions, these drugs are known to have other beneficial effects. 2. Because pathological deposition of extracellular matrix (ECM) material is a key component of remodelling after MI, we sought to determine whether atorvastatin could inhibit ECM production in vitro. 3. The addition of atorvastatin to rat cardiac fibroblasts stimulated with either transforming growth factor (TGF)-beta1 (TGF-beta1) or angiotensin (Ang) II reduced collagen synthesis in a dose-dependent manner (3.7-fold reduction (95% confidence interval (CI) 1.8-15; P < 0.01) and 5.3-fold reduction (95% CI 1.8-7.7; P < 0.01), respectively, compared with stimulant alone). Similar observations were made in human cardiac fibroblast cell culture. Atorvastatin also dose-dependently reduced TGF-beta1 and AngII-induced increases in alpha(I)-procollagen mRNA (P < 0.01 for both), as well as gene expression of the profibrotic peptide connective tissue growth factor. 4. Atorvastatin appears to directly inhibit collagen production by cardiac fibroblasts. This antifibrotic action may contribute to the antiremodelling effect of statins.

Effect of rosuvastatin on outcomes in chronic haemodialysis patients - design and rationale of the AURORA study

BACKGROUND

Patients with end-stage renal disease (ESRD) are at high risk of cardiovascular events. Multiple risk factors for atherosclerosis are present in ESRD and may contribute to the increased risk of cardiovascular mortality in this population. In contrast to patients with normal renal function, the benefits of modifying lipid levels on cardiovascular outcomes in patients with ESRD on haemodialysis have yet to be confirmed in large prospective randomised trials. A study to evaluate the Use of Rosuvastatin in subjects On Regular haemodialysis: an Assessment of survival and cardiovascular events (AURORA) will be the first large-scale international trial to assess the effects of statin therapy on cardiovascular morbidity and mortality in ESRD patients on chronic haemodialysis.

METHODS

More than 2,750 ESRD patients who have been receiving chronic haemodialysis treatment for at least 3 months have been randomised (1:1), irrespective of baseline lipid levels, to treatment with rosuvastatin 10 mg or placebo. The primary study endpoint is the time to a major cardiovascular event (first occurrence of cardiovascular death, non-fatal myocardial infarction or non-fatal stroke). Secondary endpoints include all-cause mortality, major cardiovascular event-free survival time, time to cardiovascular death, time to non-cardiovascular death, cardiovascular interventions, tolerability of treatment and health economic costs per life-year saved. Study medication will be given until 620 subjects have experienced a major cardiovascular event.

CONCLUSION

Our hypothesis is that results from AURORA will establish the clinical efficacy and tolerability of rosuvastatin in patients with ESRD receiving chronic haemodialysis and guide the optimal management of this expanding population.

Effects of simvastatin administration in an experimental model of cancer cachexia

OBJECTIVE

We evaluated whether statins, in view of their anti-inflammatory properties, may effectively prevent the onset or modulate the severity of muscle wasting during cancer cachexia.

METHODS

Simvastatin was administered to rats bearing the Yoshida AH-130 ascites hepatoma, a well-studied cytokine-dependent experimental model of cancer cachexia.

RESULTS

Quite surprisingly, the drug negatively affected the wasting pattern induced by the AH-130 hepatoma. In fact, the administration of simvastatin to tumor hosts induced a further weight reduction of all the tissues examined except for the soleus, in the absence of significant effects of simvastatin on tumor growth or on food intake. No effects were observed after simvastatin administration in control animals, with the exception of a significant (P < 0.05) reduction in heart weight.

CONCLUSIONS

Simvastatin administration, although capable of negatively modulating the inflammatory response, did not prevent muscle wasting in this experimental model of cancer cachexia. Moreover, the further muscle loss observed in simvastatin-treated tumor-bearing animals suggests that a note of caution should be introduced in treating cancer patients with statins in view of the possible occurrence of harmful side effects.

Pravastatin protection from cold stress in myocardium of rats

The aim of this research was to evaluate the possible protective effect of pravastatin on ultrastructural alterations induced by cold stress in the myocardium of rats. Sixteen EPM-Wistar rats (Rattus norvegicus albinus) were used and distributed into four groups: 1) control; 2) pravastatin; 3) cold stress, and 4) pravastatin + cold stress. A daily oral dose of 10 mg/kg of weight of pravastatin was administered to each rat in groups 2 and 4 for 15 days. The stress induced by cold was obtained by keeping the group 3 and 4 rats in a freezer at -8 degrees C for 4 hours. The animals were killed and the heart and fragments of the left ventricles (LV) were removed and processed prior to conducting electron microscopic analysis. The ultrastructural alterations in cardiomyocytes were quantified through the number of mitochondrial cristae pattern (cristalysis). The group subjected only to cold stress showed a significant increase in cristalysis (391.9) when compared with control group (42.0). In the cold stress and pravastatin pretreatment group, a statistically significant (96.9)*, P<0.05 cristalysis reduction was observed when compared with cold stress group. The mitochondrial cristalysis profiles of the control and pravastatin groups were 42.0 and 65.7, respectively. Cold stress induced a significant increase in the rate of mitochondrial cristalysis. In the group that received pravastatin and was exposed to cold stress, the drug protected the LV cardiomyocytes. This fact was confirmed by a reduction mitochondrial cristalysis pattern.

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

Epidemiologic studies have shown that hypercholesterolemia is associated with increased left ventricular (LV) mass. Free radicals have been shown to be increased in hyperlipidemic patients. This study sought to determine whether pravastatin administration can affect LV mass in patients with untreated total cholesterol >or=240 mg/dl by reducing 8-iso-prostaglandin F concentrations, a reliable marker of oxidant injury. Fifty patients were randomly assigned to one of two groups, one with (n = 25) and one without (n = 25) treatment with pravastatin (10 or 20 mg/d). A group of normolipidemic control subjects was used for comparison. Echocardiograms were performed at baseline and after 6 months of therapy. Hyperlipidemic patients showed significant increases in LV mass index at baseline compared with the normolipidemic control group (125 +/- 8 vs. 107 +/- 5 g/m, p < 0.0001). Pravastatin treatment significantly reduced plasma total and low-density lipoprotein cholesterol levels, as well as increased high-density lipoprotein cholesterol. After 6 months of therapy with pravastatin, the magnitude of LV mass regression correlated with the magnitude of inhibition of free radical formation assessed by 8-iso-prostaglandin F formation (r = 0.67, p = 0.002). Multivariate analysis revealed that regression of LV mass was significantly correlated only with the changes in 8-iso-prostaglandin F (p < 0.0001, adjusted R = 0.83). These findings demonstrated for the first time that in addition to its primary anti-lipidemia, pravastatin may have an additional effect of reducing LV mass-independent lipid-lowering effects, possibly through attenuation of free radical formation.

Lipid lowering: another method of reducing blood pressure?

Modern management of cardiovascular risk depends on assessment of cardiovascular risk factors. Hypertension and hyperlipidaemia are synergistic risk factors for cardiovascular events. Both show a degree of cross-correlation through sharing mechanisms of pathogenesis including insulin resistance and endothelial dysfunction. This article reviews the common pathways leading to dyslipidaemia and hypertension and the effects diet and lipid-lowering drug therapies have had on correcting blood pressure in patients with essential hypertension. Both statins and fibrates have shown a capability to lower blood pressure by up to 8/5 and 15/10 mmHg respectively, in some small-scale clinical trials and have effects on arterial wall structure and hence pulse wave velocity. This blood pressure action may account for some of the clinical effects of lipid-lowering drugs on cardiovascular risk. Thus, lipid lowering may provide an additional method of correcting hypertension in some high-risk patients. However, data from large-scale intervention trials are either absent or ambiguous. Definitive large-scale trials to investigate the antihypertensive effects of lipid-lowering drugs are required, although end point studies examining the interaction of lipid-lowering and antihypertensive drugs to determine optimum combinations are already under way.

Pharmacokinetic-pharmacodynamic drug interactions with HMG-CoA reductase inhibitors

The HMG-CoA reductase inhibitors (statins) are effective in both the primary and secondary prevention of ischaemic heart disease. As a group, these drugs are well tolerated apart from two uncommon but potentially serious adverse effects: elevation of liver enzymes and skeletal muscle abnormalities, which range from benign myalgias to life-threatening rhabdomyolysis. Adverse effects with statins are frequently associated with drug interactions because of their long-term use in older patients who are likely to be exposed to polypharmacy. The recent withdrawal of cerivastatin as a result of deaths from rhabdomyolysis illustrates the clinical importance of such interactions. Drug interactions involving the statins may have either a pharmacodynamic or pharmacokinetic basis, or both. As these drugs are highly extracted by the liver, displacement interactions are of limited importance. The cytochrome P450 (CYP) enzyme system plays an important part in the metabolism of the statins, leading to clinically relevant interactions with other agents, particularly cyclosporin, erythromycin, itraconazole, ketoconazole and HIV protease inhibitors, that are also metabolised by this enzyme system. An additional complicating feature is that individual statins are metabolised to differing degrees, in some cases producing active metabolites. The CYP3A family metabolises lovastatin, simvastatin, atorvastatin and cerivastatin, whereas CYP2C9 metabolises fluvastatin. Cerivastatin is also metabolised by CYP2C8. Pravastatin is not significantly metabolised by the CYP system. In addition, the statins are substrates for P-glycoprotein, a drug transporter present in the small intestine that may influence their oral bioavailability. In clinical practice, the risk of a serious interaction causing myopathy is enhanced when statin metabolism is markedly inhibited. Thus, rhabdomyolysis has occurred following the coadministration of cyclosporin, a potent CYP3A4 and P-glycoprotein inhibitor, and lovastatin. Itraconazole has been shown to increase exposure to simvastatin and its active metabolite by at least 10-fold. Pharmacodynamically, there is an increased risk of myopathy when statins are coprescribed with fibrates or nicotinic acid. This occurs relatively infrequently, but is particularly associated with the combination of cerivastatin and gemfibrozil. Statins may also alter the concentrations of other drugs, such as warfarin or digoxin, leading to alterations in effect or a requirement for clinical monitoring. Knowledge of the pharmacokinetic properties of the statins should allow the avoidance of the majority of drug interactions. If concurrent therapy with known inhibitors of statin metabolism is necessary, the patient should be monitored for signs and symptoms of myopathy or rhabdomyolysis and the statin should be discontinued if necessary.

Pharmacologic therapy of lipid disorders in the elderly

Older men and women with coronary artery disease, prior stroke, peripheral arterial disease, and extracranial carotid arterial disease with a serum low-density lipoprotein (LDL) cholesterol > 125 mg/dL despite diet should be treated with lipid-lowering drug therapy, preferably with statins, to reduce the serum LDL cholesterol to < 100 mg/dL. If statin drug therapy does not lower the serum LDL cholesterol to < 100 mg/dL in older persons with coronary artery disease, a bile acid binding resin, such as cholestyramine, should be added, since this drug does not increase the incidence of myositis in persons taking statins. The physician should use statins to treat older persons without atherosclerotic cardiovascular disease with a serum LDL cholesterol > or = 160 mg/dL plus one major risk factor, or a serum LDL cholesterol greater than or equal to 130 mg/dL plus a serum high-density lipoprotein (HDL) cholesterol < 50 mg/dL. Gemfibrozil may be useful in reducing the incidence of coronary events in persons with coronary artery disease whose primary lipid abnormality is a low serum HDL cholesterol level. There are no good data supporting treatment of hypertriglyceridemia unassociated with increased LDL cholesterol or decreased HDL cholesterol for prevention of cardiovascular disease.

Peripheral endothelium-dependent flow-mediated vasodilatation is associated with left ventricular mass in older persons with hypertension

BACKGROUND

Increased left ventricular (LV) mass is associated with greater cardiovascular disease risk. Recent studies have also shown an association of increased LV mass with attenuated endothelium-dependent coronary flow reserve. Less is known about the association between LV mass and endothelium-dependent flow-mediated dilatation (FMD) in peripheral arteries, a noninvasive measure of endothelial function.

METHODS

Sixty-two subjects with untreated mild hypertension, aged 55 to 75 years and otherwise healthy, were examined. Resting blood pressure was obtained by the average of 4 to 5 visits, each at least 1 week apart. LV mass was determined from magnetic resonance imaging and was indexed by body surface area, height and height(2.7). Body composition was assessed with dual energy x-ray absorptiometry. FMD was measured as the percent change of brachial artery diameter during reactive hyperemia by use of high-resolution ultrasound.

RESULTS

Median LV mass index was 63 g/m2 (interquartile range, 58-73). In bivariate analysis, LV mass was correlated to lean body mass (r = 0.63, P <.001), diastolic blood pressure (r = 0.35, P <.01), and FMD (r = -0.27, P <.05). In multivariate analysis, 44% of the variance in log-LV mass was explained by lean body mass. An additional 6% of the variance was explained by FMD (P <.05). For each 1% point decrease in FMD, LV mass increased by 1.1%.

CONCLUSIONS

In addition to the expected influences of body size, impairment of brachial artery FMD was independently related to LV mass in elderly subjects with mild hypertension who did not yet have LV hypertrophy. Whether mild hypertension is the common mechanism linking LV mass and endothelial function has yet to be determined.

Statins in the 21st century: end of the simple story?

The development of the HMG-CoA reductase inhibitors (the statins) has lead to important advances in the management of cardiovascular disease. There have several landmark mortality and morbidity clinical trials with the statins. The 4S (Scandinavian Simvastatin Survival Study) was the first large-scale randomised cholesterol-lowering trial to show a decrease in mortality. In patients with coronary heart disease and relatively high cholesterol, simvastatin decreased mortality, hospital stays, the risk of undergoing myocardial re-vascularisation, stroke and transient ischaemic attack. The CARE (Cholesterol and Recurrent Events) trial showed that lowering average cholesterol levels after myocardial infarction with pravastatin reduced a composite primary end point of coronary mortality and myocardial infarction, coronary bypass surgery, angioplasty and strokes. The LIPID (Long-term Intervention with Pravastatin in Ischaaemic Disease) study showed that lowering average cholesterol levels after previous myocardial infarction or unstable angina reduced mortality. WOSCOPS (The West of Scotland Coronary Prevention Study) was the first trial to demonstrate the benefit of pravastatin, as primary prevention for cardiovascular disease, in men with high cholesterol levels. AFCAPS/Tex CAPS (The Air Force/Texas Coronary Atherosclerosis Prevention Study) showed that the benefits of lowering cholesterol levels were also evident in healthy men and women who initially had average cholesterol levels. Rather surprisingly the reductions in mortality and morbidity with statins are only associated with small improvements in coronary angiographic findings. A preliminary study indicated than lovastatin prevented restenosis, but larger and better-controlled studies indicate that the statins do not have beneficial effects in restenosis. Effects other than lipid-lowering or as a consequence of their lipid-lowering may contribute to the beneficial effects of statins. These effects include improvement in vascular endothelial function, cardiac remodelling, changes in blood rheology, anti-oxidant, anti-inflammatory and anti-hypertensive actions.