Early effects on endothelial function of atorvastatin 40 mg twice daily and its withdrawal

Effects of alirocumab on endothelial function and coronary atherosclerosis in myocardial infarction: A PACMAN-AMI randomized clinical trial substudy

BACKGROUND AND AIMS

The effects of protein convertase subtilisin/kexin type 9 (PCSK9) inhibitors on endothelial function as assessed by flow-mediated dilation (FMD) in patients with acute myocardial infarction (AMI) are unknown. Therefore, we aimed to investigate the effects of the PCSK9 inhibitor alirocumab added to high-intensity statin on FMD, and its association with coronary atherosclerosis in non-infarct related arteries using intracoronary intravascular ultrasound (IVUS), near-infrared spectroscopy (NIRS), and optical coherence tomography (OCT).

METHODS

This was a pre-specified substudy among patients recruited at Bern University Hospital, Switzerland, for the randomized-controlled, double-blind, PACMAN-AMI trial, which compared the effects of biweekly alirocumab 150 mg vs. placebo added to rosuvastatin. Brachial artery FMD was measured at 4 and 52 weeks, and intracoronary imaging at baseline and 52 weeks.

RESULTS

139/173 patients completed the substudy. There was no difference in FMD at 52 weeks in the alirocumab (n = 68, 5.44 ± 2.24%) versus placebo (n = 71, 5.45 ± 2.19%) group (difference = -0.21%, 95% CI -0.77 to 0.35, p = 0.47). FMD improved throughout 52 weeks in both groups similarly (p < 0.001). There was a significant association between 4 weeks FMD and baseline plaque burden (IVUS) (n = 139, slope = -1.00, p = 0.006), but not with lipid pool (NIRS) (n = 139, slope = -7.36, p = 0.32), or fibrous cap thickness (OCT) (n = 81, slope = -1.57, p = 0.62).

CONCLUSIONS

Among patients with AMI, the addition of alirocumab did not result in further improvement of FMD as compared to 52 weeks secondary preventative medical therapy including high-intensity statin therapy. FMD was significantly associated with coronary plaque burden at baseline, but not with lipid pool or fibrous cap thickness.

Association between CVDs and initiation and adherence to statin treatment in patients with newly diagnosed hypercholesterolaemia: a retrospective cohort study

OBJECTIVES

To evaluate the association between incident cardiovascular disease (CVD) and initiation and adherence to statin treatment for primary prevention of CVD in patients with newly diagnosed hypercholesterolaemia.

DESIGN

A population-based retrospective cohort study.

SETTING

This study used National Health Insurance Service-Health Screening Cohort (NHIS-HEALS) from Republic of Korea.

PARTICIPANTS

This study included 11 320 participants without previous history of CVD aged between 40 and 79 years who had elevated total cholesterol level (more than 240 mg/dL) and had initiated statin treatment within 24 months of the national health screening from 2004 to 2012 identified in the NHIS-HEALS.

PRIMARY AND SECONDARY OUTCOME MEASURES

The primary outcome, CVD, was defined as first-ever admission or death due to ischaemic heart disease, acute myocardial infarction, revascularisation or stroke, or December 31 2013. The HRs of CVD according to statin adherence were calculated according to stratification by Systematic COronary Risk Evaluation.

RESULTS

Early statin initiation significantly lowered risk of CVD outcomes compared with late initiation (HR of late statin user, 1.24; 95% CI 1.02 to 2.51). Among early initiators, statin discontinuers had a significantly higher risk for CVD compared with persistent users (HR, 1.71; 95% CI 1.10 to 2.67), while statin reinitiators had an attenuated risk increase (HR 1.34, 95% CI 0.79 to 2.30).

CONCLUSIONS

Among statin users with newly diagnosed hypercholesterolaemia, early statin initiation is associated with lower CVD risk compared with late initiation. Furthermore, statin discontinuation is associated with increased risk of CVD, but reinitiation attenuated the risk.

Effects of different statins application methods on plaques in patients with coronary atherosclerosis

BACKGROUND

Discontinued application of statins may be related to adverse cardiovascular events. However, it is unclear whether different statins administration methods have effects on coronary artery plaques.

AIM

To evaluate the effects of different statins application methods on plaques in patients with coronary atherosclerosis.

METHODS

A total of 100 patients diagnosed with atherosclerotic plaque by coronary artery computed tomography were continuously selected and divided into three groups according to different statins administration methods (discontinued application group, n = 32; intermittent application group, n = 39; sustained application group, n = 29). The effects of the different statins application methods on coronary atherosclerotic plaque were assessed.

RESULTS

The volume change and rate of change of the most severe plaques were significantly reduced in the sustained application group (P ≤ 0.001). The volume change of the most severe plaques correlated positively with low-density lipoprotein (LDL-C) levels only in the sustained application group (R = 0.362, P = 0.013). There were no changes in plaques or LDL-C levels in the intermittent and discontinued application groups.

CONCLUSION

Continuous application of statins is effective for controlling plaque progression, whereas discontinued or intermittent administration of statins is not conducive to controlling plaques. Only with continuous statins administration can a reduction in LDL-C levels result in plaque volume shrinkage.

Effect of atorvastatin on testosterone levels

BACKGROUND

Statins are one of the most prescribed classes of drugs worldwide. Atorvastatin, the most prescribed statin, is currently used to treat conditions such as hypercholesterolaemia and dyslipidaemia. By reducing the level of cholesterol, which is the precursor of the steroidogenesis pathway, atorvastatin may cause a reduction in levels of testosterone and other androgens. Testosterone and other androgens play important roles in biological functions. A potential reduction in androgen levels, caused by atorvastatin might cause negative effects in most settings. In contrast, in the setting of polycystic ovary syndrome (PCOS), reducing excessive levels of androgens with atorvastatin could be beneficial.

OBJECTIVES

Primary objective To quantify the magnitude of the effect of atorvastatin on total testosterone in both males and females, compared to placebo or no treatment. Secondary objectives To quantify the magnitude of the effects of atorvastatin on free testosterone, sex hormone binding globin (SHBG), androstenedione, dehydroepiandrosterone sulphate (DHEAS) concentrations, free androgen index (FAI), and withdrawal due to adverse effects (WDAEs) in both males and females, compared to placebo or no treatment.

SEARCH METHODS

The Cochrane Hypertension Information Specialist searched the following databases for randomized controlled trials (RCTs) up to 9 November 2020: the Cochrane Hypertension Specialised Register; the Cochrane Central Register of Controlled Trials (CENTRAL); MEDLINE; Embase; ;two international trials registries, and the websites of the US Food and Drug Administration, the European Patent Office and the Pfizer pharmaceutical corporation. These searches had no language restrictions. We also contacted authors of relevant articles regarding further published and unpublished work.

SELECTION CRITERIA

RCTs of daily atorvastatin for at least three weeks, compared with placebo or no treatment, and assessing change in testosterone levels in males or females.

DATA COLLECTION AND ANALYSIS

Two review authors independently screened the citations, extracted the data and assessed the risk of bias of the included studies. We used the mean difference (MD) with associated 95% confidence intervals (CI) to report the effect size of continuous outcomes,and the risk ratio (RR) to report effect sizes of the sole dichotomous outcome (WDAEs). We used a fixed-effect meta-analytic model to combine effect estimates across studies, and risk ratio to report effect size of the dichotomous outcomes. We used GRADE to assess the certainty of the evidence.

MAIN RESULTS

We included six RCTs involving 265 participants who completed the study and their data was reported. Participants in two of the studies were male with normal lipid profile or mild dyslipidaemia (N = 140); the mean age of participants was 68 years. Participants in four of the studies were female with PCOS (N = 125); the mean age of participants was 32 years. We found no significant difference in testosterone levels in males between atorvastatin and placebo, MD -0.20 nmol/L (95% CI -0.77 to 0.37). In females, atorvastatin may reduce total testosterone by -0.27 nmol/L (95% CI -0.50 to -0.04), FAI by -2.59 nmol/L (95% CI -3.62 to -1.57), androstenedione by -1.37 nmol/L (95% CI -2.26 to -0.49), and DHEAS by -0.63 μmol/l (95% CI -1.12 to -0.15). Furthermore, compared to placebo, atorvastatin increased SHBG concentrations in females by 3.11 nmol/L (95% CI 0.23 to 5.99). We identified no studies in healthy females (i.e. females with normal testosterone levels) or children (under age 18). Importantly, no study reported on free testosterone levels.

AUTHORS' CONCLUSIONS

We found no significant difference between atorvastatin and placebo on the levels of total testosterone in males. In females with PCOS, atorvastatin lowered the total testosterone, FAI, androstenedione, and DHEAS. The certainty of evidence ranged from low to very low for both comparisons. More RCTs studying the effect of atorvastatin on testosterone are needed.

Coronary and peripheral artery plaques: do differences in plaque characteristics translate to differences in lipid management?

Optimal medical management of patients with peripheral arterial disease (PAD) includes statin therapy, which has been shown to decrease the risk of major cardiovascular events. However, the relationship between low-density lipoprotein (LDL) lowering, PAD progression and limb outcomes remains controversial. Although prevention of coronary and cerebrovascular events is a priority, limb outcomes are still important determinants of quality of life and healthcare spending. This review will highlight differences between coronary artery disease (CAD) and PAD, and in particular, the more prevalent role of lipids and LDL cholesterol in CAD versus calcification in PAD. This difference may contribute to the differential impact of LDL cholesterol levels on coronary events and outcomes versus limb outcomes. Beyond LDL lowering, immune modulators have emerged as another agent to treat atherosclerosis in CAD, however similar data in PAD are lacking. Small studies have suggested that other lipids besides LDL cholesterol, such as triglycerides or small dense LDL, may have a greater impact on limb outcomes in patients with PAD. Although statin therapy is central in the management of patients with PAD, current understanding of the distinctions between PAD and CAD suggest that there may be other non-LDL targets for risk reduction that require further study.

Improvement of endothelial function by pitavastatin: a meta-analysis

OBJECTIVE

Dyslipidemia is commonly associated with endothelial dysfunction and increased cardiovascular risk. Pitavastatin has been shown to reduce total and low-density lipoprotein cholesterol, to increase high-density lipoprotein (HDL)-cholesterol and improve HDL function. Furthermore, several trials explored its effects on flow-mediated dilation (FMD), as an index of endothelial function. The authors evaluated the effect of pitavastatin therapy on FMD.

METHODS

The authors performed a systematic review and meta-analysis of all clinical trials exploring the impact of pitavastatin on FMD. The search included PubMed-Medline, Scopus, ISI Web of Knowledge and Google Scholar databases. Quantitative data synthesis was performed using a random-effects model, with weighted mean difference (WMD) and 95% confidence interval (CI) as summary statistics.

RESULTS

Six eligible studies comprising 7 treatment arms were selected for this meta-analysis. Overall, WMD was significant for the effect of pitavastatin on FMD (2.45%, 95% CI: 1.31, 3.60, p < 0.001) and the effect size was robust in the leave-one-out sensitivity analysis.

CONCLUSION

This meta-analysis of all available clinical trials revealed a significant increase of FMD induced by pitavastatin.

The association between prior statin use and long-term outcomes after critical care admission

BACKGROUND

Statins may have immunomodulatory effects that benefit critically ill patients. Therefore, we retrospectively examined the association between survival and the prescription of statins prior to admission to an intensive care unit (ICU), or high dependency unit (HDU), as a result of major elective surgery or as an emergency with a presumed diagnosis of sepsis.

METHODS

We retrospectively studied critical care patients (ICU or HDU) from a tertiary referral UK teaching hospital. Nottingham University Hospitals have more than 2200 beds, of which 39 are critical care beds. Over a 5-year period (2000-2005), 414 patients were identified with a presumed diagnosis of sepsis, and 672 patients were identified who had planned ICU/HDU admissions following elective major surgery. Patients prescribed statins prior to hospital admission were compared with those who were not. Demographics, medical history, drug history, and Acute Physiology and Chronic Health Evaluation II scores were examined. Univariate and multivariate analyses were applied using the primary end point of survival at 5 years after admission.

RESULTS

Patients prescribed statins prior to critical care admission were, on average, older and had higher initial Acute Physiology and Chronic Health Evaluation II scores and more preexisting comorbidities. Statins were almost invariably stopped following admission to critical care. Statin use was not associated with significantly altered survival during hospital admission, or at 5 years, for either patients with sepsis (9% vs 15%, P=.121; 73% vs 84%, P=.503, respectively) or postoperative patients (55% vs 58%, P=.762; 57% vs 63%, P=.390).

CONCLUSIONS

Prior statin use was not associated with improved outcomes in patients admitted to critical care after elective surgical cases or with a presumed diagnosis of sepsis.

Neurovascular coupling in humans: Physiology, methodological advances and clinical implications

Neurovascular coupling reflects the close temporal and regional linkage between neural activity and cerebral blood flow. Although providing mechanistic insight, our understanding of neurovascular coupling is largely limited to non-physiologicalex vivopreparations and non-human models using sedatives/anesthetics with confounding cerebrovascular implications. Herein, with particular focus on humans, we review the present mechanistic understanding of neurovascular coupling and highlight current approaches to assess these responses and the application in health and disease. Moreover, we present new guidelines for standardizing the assessment of neurovascular coupling in humans. To improve the reliability of measurement and related interpretation, the utility of new automated software for neurovascular coupling is demonstrated, which provides the capacity for coalescing repetitive trials and time intervals into single contours and extracting numerous metrics (e.g., conductance and pulsatility, critical closing pressure, etc.) according to patterns of interest (e.g., peak/minimum response, time of response, etc.). This versatile software also permits the normalization of neurovascular coupling metrics to dynamic changes in arterial blood gases, potentially influencing the hyperemic response. It is hoped that these guidelines, combined with the newly developed and openly available software, will help to propel the understanding of neurovascular coupling in humans and also lead to improved clinical management of this critical physiological function.

Technical recommendations for the use of carotid duplex ultrasound for the assessment of extracranial blood flow

Duplex ultrasound is an evolving technology that allows the assessment of volumetric blood flow in the carotid and vertebral arteries during a range of interventions along the spectrum of health and chronic disease. Duplex ultrasound can provide high-resolution diameter and velocity information in real-time and is noninvasive with minimal risks or contraindications. However, this ultrasound approach is a specialized technique requiring intensive training and stringent control of multiple complex settings; results are highly operator-dependent, and analysis approaches are inconsistent. Importantly, therefore, methodological differences can invalidate comparisons between different imaging modalities and studies; such methodological errors have potential to discredit study findings completely. The task of this review is to provide the first comprehensive, user-friendly technical guideline for the application of duplex ultrasound in measuring extracranial blood flow in human research. An update on recent developments in the use of edge-detection software for offline analysis is highlighted, and suggestions for future directions in this field are provided. These recommendations are presented in an attempt to standardize measurements across research groups and, hence, ultimately to improve the accuracy and reproducibility of measuring extracranial blood flow both within subjects and between groups.

Pleiotropic effects of statins

Statins or 3-hydroxy-methylglutaryl coenzyme A (HMG CoA) reductase inhibitors not only prevents the synthesis of cholesterol biosynthesis but also inhibits the synthesis of essential isoprenoid intermediates such as farnesyl pyrophosphate, geranylgeranyl pyrophosphate, isopentanyl adenosine, dolichols and polyisoprenoid side chains of ubiquinone, heme A, and nuclear lamins. These isoprenoid intermediates are required for activation of various intracellular/signaling proteins- small guanosine triphosphate bound protein Ras and Ras-like proteins like Rho, Rab, Rac, Ral, or Rap which plays an indispensible role in multiple cellular processes. Reduction of circulating isoprenoids intermediates as a result of HMG CoA reductase inhibition by statins prevents activation of these signalling proteins. Hence, the multiple effects of statins such as antiinflammatory effects, antioxidant effects, antiproliferative and immunomodulatory effects, plaque stability, normalization of sympathetic outflow, and prevention of platelet aggregation are due to reduction of circulating isoprenoids and hence inactivation of signalling proteins. These multiple lipid-independent effects of statins termed as statin pleiotropy would potentially open floodgates for research in multiple treatment domains catching attentions of researchers and clinician across the globe.

Endothelial dysfunction in conduit arteries and in microcirculation. Novel therapeutic approaches

The vascular endothelium not only is a single monolayer of cells between the vessel lumen and the intimal wall, but also plays an important role by controlling vascular function and structure mainly via the production of nitric oxide (NO). The so called "cardiovascular risk factors" are associated with endothelial dysfunction, that reduces NO bioavailability, increases oxidative stress, and promotes inflammation contributing therefore to the development of atherosclerosis. The significant role of endothelial dysfunction in the development of atherosclerosis emphasizes the need for efficient therapeutic interventions. During the last years statins, angiotensin-converting enzyme inhibitors, angiotensin-receptor antagonists, antioxidants, beta-blockers and insulin sensitizers have been evaluated for their ability to restore endothelial function (Briasoulis et al., 2012). As there is not a straightforward relationship between therapeutic interventions and improvement of endothelial function but rather a complicated interrelationship between multiple cellular and sub-cellular targets, research has been focused on the understanding of the underlying mechanisms. Moreover, the development of novel diagnostic invasive and non-invasive methods has allowed the early detection of endothelial dysfunction expanding the role of therapeutic interventions and our knowledge. In the current review we present the available data concerning the contribution of endothelial dysfunction to atherogenesis and review the methods that assess endothelial function with a view to understand the multiple targets of therapeutic interventions. Finally we focus on the classic and novel therapeutic approaches aiming to improve endothelial dysfunction and the underlying mechanisms.

Rosuvastatin does not affect fasting glucose, insulin resistance, or adiponectin in patients with mild to moderate hypertension

The effects of statins on insulin resistance and new-onset diabetes are unclear. The purpose of this study was to evaluate the effects of rosuvastatin on insulin resistance and adiponectin in patients with mild to moderate hypertension. In a randomized, prospective, single-blind study, 53 hypertensive patients were randomly assigned to the control group (n=26) or the rosuvastatin (20 mg once daily) group (n=27) during an 8-week treatment period. Both groups showed significant improvements in systolic blood pressure and flow-mediated dilation (FMD) after 8 weeks of treatment. Rosuvastatin treatment improved total cholesterol, low-density lipoprotein (LDL)-cholesterol, and triglyceride levels. The control and rosuvastatin treatment groups did not differ significantly in the change in HbA1c (3.0±10.1% vs. -1.3±12.7%; p=0.33), fasting glucose (-1.3±18.0% vs. 2.5±24.1%; p=0.69), or fasting insulin levels (5.2±70.5% vs. 22.6±133.2%; p=0.27) from baseline. Furthermore, the control and rosuvastatin treatment groups did not differ significantly in the change in the QUICKI insulin sensitivity index (mean change, 2.2±11.6% vs. 3.6±11.9%; p=0.64) or the HOMA index (11.6±94.9% vs. 32.4±176.7%; p=0.44). The plasma adiponectin level increased significantly in the rosuvastatin treatment group (p=0.046), but did not differ significantly from that in the control group (mean change, 23.2±28.4% vs. 23.1±27.6%; p=0.36). Eight weeks of rosuvastatin (20 mg) therapy resulted in no significant improvement or deterioration in fasting glucose levels, insulin resistance, or adiponectin levels in patients with mild to moderate hypertension.

Brachial artery diameter and the right ventricle: the Multi-Ethnic Study of Atherosclerosis-right ventricle study

BACKGROUND

Endothelial dysfunction is associated with left ventricular morphology and long-term cardiovascular outcomes. The purpose of this study was to assess the relationship between both baseline brachial artery diameter and peripheral endothelial function (assessed by brachial artery ultrasonography) and right ventricular (RV) mass, RV end-diastolic volume (RVEDV), and RV ejection fraction (RVEF).

METHODS

The Multi-Ethnic Study of Atherosclerosis (MESA) performed cardiac MRI and brachial artery ultrasonography on participants without clinical cardiovascular disease. Baseline brachial artery diameter and flow-mediated dilation were assessed.

RESULTS

The mean age was 60.9 years, and 49.4% of subjects were men (n = 2,425). In adjusted models, larger brachial artery diameter was strongly associated with greater RV mass (β = 0.55 g, P &lt; .001), larger RVEDV (β = 3.99 mL, P &lt; .001), and decreased RVEF (β = -0.46%, P = .03). These relationships persisted after further adjustment for the respective left ventricular parameters. Flow-mediated dilation was not associated with RV mass or RVEF and was only weakly associated with RVEDV.

CONCLUSIONS

Brachial artery diameter is associated with greater RV mass and RVEDV, as well as lower RVEF. Changes in the systemic arterial circulation may have pathophysiologic links to pulmonary vascular dysfunction or abnormalities in RV perfusion.

Activator protein-1 (AP-1) signalling in human atherosclerosis: results of a systematic evaluation and intervention study

Animal studies implicate the AP-1 (activator protein-1) pro-inflammatory pathway as a promising target in the treatment of atherosclerotic disease. It is, however, unclear whether these observations apply to human atherosclerosis. Therefore we evaluated the profile of AP-1 activation through histological analysis and tested the potential benefit of AP-1 inhibition in a clinical trial. AP-1 activation was quantified by phospho-c-Jun nuclear translocation (immunohistochemistry) on a biobank of aortic wall samples from organ donors. The effect of AP-1 inhibition on vascular parameters was tested through a double blind placebo-controlled cross-over study of 28 days doxycycline or placebo in patients with symptomatic peripheral artery disease. Vascular function was assessed by brachial dilation as well as by plasma samples analysed for hs-CRP (high-sensitivity C-reactive protein), IL-6 (interleukin-6), IL-8, ICAM-1 (intercellular adhesion molecule-1), vWF (von Willebrand factor), MCP-1 (monocyte chemoattractant protein-1), PAI-1 (plasminogen activator inhibitor-1) and fibrinogen. Histological evaluation of human atherosclerosis showed minimal AP-1 activation in non-diseased arterial wall (i.e. vessel wall without any signs of atherosclerotic disease). A gradual increase of AP-1 activation was found in non-progressive and progressive phases of atherosclerosis respectively (P<0.044). No significant difference was found between progressive and vulnerable lesions. The expression of phospho-c-Jun diminished as the lesion stabilized (P<0.016) and does not significantly differ from the normal aortic wall (P<0.33). Evaluation of the doxycycline intervention only revealed a borderline-significant reduction of circulating hs-CRP levels (-0.51 μg/ml, P=0.05) and did not affect any of the other markers of systemic inflammation and vascular function. Our studies do not characterize AP-1 as a therapeutic target for progressive human atherosclerotic disease.

Recent development in pleiotropic effects of statins on cardiovascular disease through regulation of transforming growth factor-beta superfamily

BACKGROUND

3-Hydroxy-3-methylglutaryl-coenzyme A (HMG-CoA) reductase inhibitors, also known as statins, are a drug class that reduce the level of cholesterol in the blood. As a result, statins are used to suppress the progression of cardiovascular disease. Evidence points to another component of statins involving the non-lipid effects of the drug class in preventing cardiovascular disease. One specific mediator of this action is the transforming growth factor β (TGF-β) superfamily. The TGF-β superfamily consists of proteins that include TGF-β and bone morphogenetic proteins (BMPs). These proteins regulate cellular pathways to mediate effects including immunomodulation, cell cycling, and angiogenesis. One pathway that mediates these effects is Ras. Moreover, within this pathway, different functions are possible depending on the activation of the specific receptor subtype. This review discusses the recent development of the non-lipid effects of statins in preventing cardiovascular disease progression by regulating Ras pathway of the TGF-β superfamily, especially RhoA/ROCK pathway.

METHODS

A systematic PubMed database search of all English-language articles up to 2011 was conducted using the following terms: statin, TGF-β, Ras, ROCK, GGPP, inducible nitric oxide synthase, endothelial nitric oxide synthase, actin filament formation, PPARγ, MMP-2, and human trials.

CONCLUSION

With better understanding of the pathway, various mediators were identified; some of these mediators are important biomarkers producing more specific and accurate assessment of the pleiotropic effects of statins. The review of human trials also highlights that more specific biomarkers are employed in recent studies, and the non-lipid effects on human subjects are more accurately documented. Confirmation of the accuracy of these biomarkers by further large-scale studies and further development of new biomarkers may prove an important path leading to better patient selection for treatment, and thus better cost-effectiveness may be achieved.

Assessment of flow-mediated dilation in humans: a methodological and physiological guideline

Endothelial dysfunction is now considered an important early event in the development of atherosclerosis, which precedes gross morphological signs and clinical symptoms. The assessment of flow-mediated dilation (FMD) was introduced almost 20 years ago as a noninvasive approach to examine vasodilator function in vivo. FMD is widely believed to reflect endothelium-dependent and largely nitric oxide-mediated arterial function and has been used as a surrogate marker of vascular health. This noninvasive technique has been used to compare groups of subjects and to evaluate the impact of interventions within individuals. Despite its widespread adoption, there is considerable variability between studies with respect to the protocols applied, methods of analysis, and interpretation of results. Moreover, differences in methodological approaches have important impacts on the response magnitude, can result in spurious data interpretation, and limit the comparability of outcomes between studies. This review results from a collegial discussion between physiologists with the purpose of developing considered guidelines. The contributors represent several distinct research groups that have independently worked to advance the evidence base for improvement of the technical approaches to FMD measurement and analysis. The outcome is a series of recommendations on the basis of review and critical appraisal of recent physiological studies, pertaining to the most appropriate methods to assess FMD in humans.

Preoperative atorvastatin treatment in CABG patients rapidly improves vein graft redox state by inhibition of Rac1 and NADPH-oxidase activity

BACKGROUND

Statins improve clinical outcome of patients with atherosclerosis, but their perioperative role in patients undergoing coronary artery bypass grafting (CABG) is unclear. We hypothesized that short-term treatment with atorvastatin before CABG would improve the redox state in saphenous vein grafts (SVGs), independently of low-density lipoprotein cholesterol (LDL)-lowering.

METHODS AND RESULTS

In a randomized, double-blind controlled trial, 42 statin-naïve patients undergoing elective CABG received atorvastatin 40 mg/d or placebo for 3 days before surgery. Circulating inflammatory markers and malondialdehyde (MDA) were measured before and after treatment. SVG segments were used to determine vascular superoxide (O(2)(*-)) and Rac1 activation. For ex vivo studies, SVG segments from 24 patients were incubated for 6 hours with atorvastatin 0, 5, or 50 μmol/L. Oral atorvastatin reduced vascular basal and NADPH-stimulated O(2)(*-) in SVGs (P<0.05 for all versus placebo) and reduced plasma MDA (P<0.05), independently of LDL-lowering and of changes in inflammatory markers. In SVGs exposed to atorvastatin ex vivo, without exposure to LDL, basal and NADPH-stimulated O(2)(·-) were significantly reduced (P<0.01 for both concentrations versus 0 μmol/L) in association with a striking reduction in Rac1 activation and 1 membrane-bound Rac1 and p67(phox) subunit. The antioxidant effects of atorvastatin were reversed by mevalonate, implying a dependence on vascular HMG-CoA reductase inhibition.

CONCLUSIONS

Short-term treatment with atorvastatin 40 mg/d before CABG improves redox state in SVGs, by inhibiting vascular Rac1-mediated activation of NADPH-oxidase. These novel findings suggest that statin therapy should be maintained or initiated in patients undergoing CABG, independently of LDL levels. Clinical Trial Registration-URL: http://www.clinicaltrials.gov. Unique identifier: NCT01013103.

Ingestion of broccoli sprouts does not improve endothelial function in humans with hypertension

Ingestion of glucosinolates has previously been reported to improve endothelial function in spontaneously hypertensive rats, possibly because of an increase in NO availability in the endothelium due to an attenuation of oxidative stress; in our study we tried to see if this also would be the case in humans suffering from essential hypertension.

Methods

40 hypertensive individuals without diabetes and with normal levels of cholesterol were examined. The participants were randomized either to ingest 10 g dried broccoli sprouts, a natural donor of glucosinolates with high in vitro antioxidative potential, for a 4 week period or to continue their ordinary diet and act as controls. Blood pressure, endothelial function measured by flow mediated dilation (FMD) and blood samples were obtained from the participants every other week and the content of glucosinolates was measured before and after the study. Measurements were blinded to treatment allocation.

Results

In the interventional group overall FMD increased from 4% to 5.8% in the interventional group whereas in the control group FMD was stable (4% at baseline and 3.9% at the end of the study). The change in FMD in the interventional group was mainly due to a marked change in FMD in two participants while the other participants did not have marked changes in FMD. The observed differences were not statistically significant. Likewise significant changes in blood pressure or blood samples were not detected between or within groups. Diastolic blood pressure stayed essentially unchanged in both groups, while the systolic blood pressure showed a small non significant decrease (9 mm Hg) in the interventional group from a value of 153 mm Hg at start.

Conclusion

Daily ingestion of 10 g dried broccoli sprouts does not improve endothelial function in the presence of hypertension in humans.

Trial Registration

Clinicaltrials.gov NCT00252018

Assessing individual cardiac risk using extra-cardiac arterial imaging

Cardiovascular disease is the leading cause of death globally. Cardiovascular risk factors predict the risk of cardiovascular events in populations but have limitations in predicting individual risk. Emerging technologies that non-invasively measure carotid intima media thickness, aortic pressure and brachial artery reactivity may be useful in identifying the vulnerable patient who may benefit from more aggressive preventive therapy. These tests vary between each other in their reproducibility, cost, required operator skill, availability and patient preparation. However, all require further validation for clinical use as screening tests for cardiovascular disease.

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.

Predictive value of brachial flow-mediated dilation for incident cardiovascular events in a population-based study: the multi-ethnic study of atherosclerosis

BACKGROUND

Although brachial artery flow-mediated dilation (FMD) predicts recurrent cardiovascular events, its predictive value for incident cardiovascular disease (CVD) events in adults free of CVD is not well established. We assessed the predictive value of FMD for incident CVD events in the Multi-Ethnic Study of Atherosclerosis (MESA).

METHODS AND RESULTS

Brachial artery FMD was measured in a nested case-cohort sample of 3026 of 6814 subjects (mean+/-SD age, 61.2+/-9.9 years) in MESA, a population-based cohort study of adults free of clinical CVD at baseline recruited at 6 clinic sites in the United States. The sample included 50.2% female, 34.3% white, 19.7% Chinese, 20.8% black, and 25.1% Hispanic subjects. Probability-weighted Cox proportional hazards analysis was used to examine the association between FMD and 5 years of adjudicated incident CVD events, including incident myocardial infarction, definite angina, coronary revascularization (coronary artery bypass grafting, percutaneous transluminal coronary angioplasty, or other revascularization), stroke, resuscitated cardiac arrest, and CVD death. Mean (SD) FMD of the cohort was 4.4% (2.8). In probability-weighted Cox models, FMD/unit SD was significantly associated with incident cardiovascular events in the univariate model (adjusted for age and sex) (hazard ratio, 0.79; 95% confidence interval, 0.65 to 0.97; P=0.01), after adjustment for the Framingham Risk Score (FRS) (hazard ratio, 0.80; 95% confidence interval, 0.62 to 0.97; P=0.025), and in the multivariable model (hazard ratio, 0.84; 95% confidence interval, 0.71 to 0.99; P=0.04) after adjustment for age, sex, diabetes mellitus, cigarette smoking status, systolic blood pressure, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, triglycerides, heart rate, statin use, and blood pressure medication use. The c statistic (area under the curve) values of FMD, FRS, and FRS+FMD were 0.65, 0.74, and 0.74, respectively. Compared with the FRS alone, the addition of FMD to the FRS net correctly reclassifies 52% of subjects with no incident CVD event but net incorrectly reclassifies 23% of subjects with an incident CVD event, an overall net correct reclassification of 29% (P<0.001).

CONCLUSIONS

Brachial FMD is a predictor of incident cardiovascular events in population-based adults. Even though the addition of FMD to the FRS did not improve discrimination of subjects at risk of CVD events in receiver operating characteristic analysis, it improved the classification of subjects as low, intermediate, and high CVD risk compared with the FRS.

[Endothelial dysfunction in type 1 diabetes]

Vascular complications are the main cause of mortality and morbidity in diabetes. Mechanisms involved in the development of micro and macrovascular disease are complex and partially understood, but invariably begin as a dysfunctional endothelium. Nitric oxide is an important regulator of endothelial function and the impairment of its activity is determinant of the endothelial dysfunction. In type 1 diabetes, many factors like acute, chronic and post-prandial hyperglycemia, as well as the duration of diabetes or autonomic neuropathy and microalbuminuria are associated to endothelial dysfunction. Oxidative stress, polyol pathway activation, protein kinase C activation and the presence of advanced glycation end-products are potential mechanisms involved in the development of endothelial dysfunction. Early detection of endothelial dysfunction has prognostic value for the development of vascular complications and may be important in strategies for primary prevention of cardiovascular endpoints in type 1 diabetes.

Different galenic formulations of fluvastatin have equal lipid-lowering potential but differ in reducing lipemia-induced endothelial dysfunction

BACKGROUND

Postprandial lipemia is known to exert a reversible detrimental effect on endothelium-dependent flow-mediated vasodilation (FMD). Fasting FMD has shown to be improved by fluvastatin. In this study, we investigated whether lipemia-induced endothelial dysfunction can be mitigated by fluvastatin in two (immediate-release and extended-release) formulations.

METHODS

In 27 patients with the metabolic syndrome, randomized in a three-period crossover design for 5 weeks each to 80 mg extended-release fluvastatin daily, 40 mg immediate-release fluvastatin twice daily (b.i.d.) or placebo, the fasting and postprandial lipids and FMD of the brachial artery were measured at baseline and after 5 weeks of each treatment period. Postprandial lipemia was induced by administration of whipping cream containing 33% fat (1 g fat/kg body weight). FMD was determined by two-dimensional ultrasonography of the brachial artery in the fasting state and 4 h after the fatty meal. Lipids were determined using routine methods.

RESULTS

Fasting triglycerides were reduced after immediate-release and extended-release fluvastatin by 16 and 23%, respectively, and postprandial triglycerides by 20 and 29%, respectively. The fasting FMD was also improved by each treatment. The postprandial FMD impairment, however, was mitigated only after 40 mg b.i.d. After 80 mg fluvastatin, the last dose of which had been administered the previous evening, the lipemic FMD impairment was the same as after the placebo.

CONCLUSION

Fluvastatin improves fasting FMD regardless of whether it is administered as 40 mg b.i.d. or 80 mg daily given in the evening. The lipemic FMD impairment, in contrast, is improved only by 40 mg b.i.d. when the tablet is taken in the morning of the test day. As the half-life of fluvastatin is about 2 h, we surmise that an improvement occurs only when sufficient amounts of fluvastatin are present in the bloodstream.

Statin discontinuation: an underestimated risk?

Statin treatment is essential for the prevention of vascular disease. Despite the established benefits of statins, discontinuation of these agents is frequent. Whether statin discontinuation leads to adverse outcomes is still debated and the most convincing evidence is mainly restricted to patients who experienced an acute vascular event. It is important to establish if this phenomenon extends to other populations, like those without vascular disease but with a high calculated risk. Overall, it appears that even a brief discontinuation of statins might be harmful. Therefore, statin treatment should not be interrupted except if there is a very good reason. Moreover, patients should be instructed as to why they must adhere to their medication. Adherence should be monitored regularly.

The association of acute exercise-induced ischaemia with systemic vasodilator function in patients with peripheral arterial disease

Abstract

Patients with peripheral arterial disease (PAD) frequently experience ischaemic attacks of the affected tissues during exercise. The present study assesses the association of transient exercise-induced leg ischaemia with vasodilator function of the clinically unaffected brachial artery over the course of 4 hours. Thirty male patients with symptomatic PAD and 14 age- and sex-matched healthy controls were included in the study. They performed a treadmill exercise until intolerable exercise-induced ischaemic pain occurred in the affected lower extremity, or for at most 10 min. Flow-mediated dilation (FMD) of the brachial artery was measured at baseline, 30 minutes, 2 hours and 4 hours after exercise. Baseline FMD values were significantly diminished in patients (7.03 ± 1.99% vs 8.22 ± 1.60% in controls, p = 0.009). A significant decrease in FMD was observed in patients after exercise (at 30 minutes: 3.92 ± 1.78% vs 7.03 ± 1.99% at baseline, p < 0.001; at 2 hours: 6.36 ± 2.12% vs 7.03 ± 1.99% at baseline, p = 0.005), followed by a gradual return to its baseline value, whereas FMD in controls non-significantly increased after exercise. The difference in the pattern of FMD change over time between patients and controls was significant ( p < 0.001). This study shows that in PAD patients ischaemia during intermittent claudication is related to a transitory functional deterioration of the distant arteries. This indicates the harmful systemic effects of repeated ischaemic attacks during exercise and might explain the generalized and advanced nature of atherosclerotic disease in PAD patients.

Short term effects of atorvastatin on endothelial functions and oxidized LDL levels in patients with type 2 diabetes

OBJECTIVE

This study was designed in order to investigate the short term effects of atorvastatin on endothelial function and oxidized LDL (oxLDL) levels and to evaluate the association of endothelial dysfunction to oxLDL levels and inflammatory markers in type 2 diabetic patients.

MATERIAL AND METHODS

Thirty type 2 diabetic and 11 healthy subjects with LDL levels between 100-160 mg/dl. without a history of cardiovascular event were included in the study. Both groups were matched with respect to age, gender, body mass indices and lipid levels. Flow- mediated dilatation (endothelium dependent, FMD) and nitroglycerine-induced dilatation (endothelium independent, NID) were measured in the brachial artery using high-resolution ultrasound in all participants and carotid artery intima media thickness (IMT) were also evaluated. OxLDL levels, lipid parameters, blood glucose, C-peptide, HbA1c and inflammatory markers including C-reactive protein (CRP), fibrinogen, erythrocyte sedimentation rate (ESR) were studied. Type 2 diabetic patients received 10 mg. Atorvastatin for 6 weeks and FMD and NID were reevaluated and oxLDL levels and inflammatory markers remeasured.

RESULTS

Basal FMD, NID, IMT and oxLDL levels besides inflammatory markers were not significantly different between patients and controls. No correlation was found between inflammatory markers and FMD and NID. Only IMT correlated with fibrinogen levels obtained before treatment. In non-diabetics, IMT also correlated with oxLDL levels (p: 0.013). FMD and NID significantly improved after atorvastatin therapy ((7.62 +/- 7.6 vs. 12.65 +/- 7.8, p<0.001 and 18.22 +/- 9.57 vs. 21.43 +/- 9.6, p: 0.007, respectively). Atorvastatin significantly reduced oxLDL levels (57.85 +/- 10.33 vs. 44.36 +/- 6.34, p<0.001).

CONCLUSION

Atorvastatin improves endothelial functions and reduces oxLDL levels in type 2 diabetics with average lipid levels in the short term and may have beneficial effects in the prevention of early atherosclerotic changes.

Fluvastatin Treatment and Withdrawal: Effects on Endothelial Function

Fluvastatin lowers lipids and protects endothelial function. This study investigated how 2 preparations of fluvastatin would affect endothelial function after treatment and early after its discontinuation. Twenty-seven patients received 80 mg extended-release fluvastatin every day, 40 mg immediate-release fluvastatin twice a day, or placebo for 5 weeks. Fasting lipids and flow-mediated dilation were measured at baseline and after each treatment period. In 21 patients, flow-mediated vasodilation was also measured 24 hours after discontinuation of therapy. Both forms of fluvastatin improved flow-mediated vasodilation (extended release: P < .037 and immediate release: P < .001). However, this improvement occurred preferentially in patients with low baseline flow-mediated vasodilation (<5%). Twenty-four hours after treatment discontinuation, the flow-mediated vasodilation deteriorated again to baseline (extended release and immediate release: P < .001). Fluvastatin improved flow-mediated vasodilation only in patients with low baseline values. Twenty-four hours after discontinuation, the flow-mediated vasodilation deteriorated again, surprisingly irrespective of prior improvement.

Improvement in endothelium dysfunction in diabetics treated with statins: a randomized comparison of atorvastatin 20 mg versus rosuvastatin 10 mg

AIM

To investigate the effect a 3-month treatment with atorvastatin 20 mg compared with rosuvastatin 10 mg on endothelium dysfunction in subjects with diabetes.

METHODS

A total of 22 consecutive subjects with diabetes who were not receiving statins were enrolled in the study. Endothelium function was assessed before treatment (T0), after 1 month (T1), and after 3 months of treatment (T2) with statins with brachial echo-Doppler test. Patients were randomized to receive atorvastatin 20 mg or rosuvastatin 10 mg. Blood samples were drawn in the meantime in order to evaluate C-reactive protein (CRP) plasmatic concentrations.

RESULTS

A total of 82% of patients enrolled showed endothelium dysfunction (hyperemic reserve <5%). Treatment with statins significantly improved endothelium function in diabetics. Subjects with endothelium dysfunction decreased from 82% (T0) to 44% (T2): mean hyperemic reserve values increased from 2.64% (T0) to 3.23% (T1) and 4% (T2) in patients treated with rosuvastatin (ANOVA P < 0.01), and from 2.74% (T0) to 2.75% (T1) and 4.40% (T2) in those treated with atorvastatin (ANOVA P < 0.01); differences were significant only comparing T2 with T0. Relative increase in endothelium reserve was 51.51% with rosuvastatin versus 60.58% with atorvastatin (P N.S.). Both statins significantly reduced plasmatic levels of CRP (3.18 +/- 2.43 mg/dL [T0] vs. 1.31 +/- 1.67 mg/dL [T2] with rosuvastatin [P < 0.01], 7.53 +/- 7.46 mg/dL [T0] vs. 2.92 +/- 2.06 mg/dL [T2] with atorvastatin [P < 0.01]). Relative reduction of CRP levels was -50.57% with rosuvastatin versus -36.28% with atorvastatin (P N.S.).

CONCLUSION

A 3-month treatment with either atorvastatin 20 mg or rosuvastatin 10 mg is effective in improving endothelium dysfunction in subjects with diabetes.

The Impact of Postoperative Discontinuation or Continuation of Chronic Statin Therapy on Cardiac Outcome After Major Vascular Surgery

BACKGROUND

Statins reduce cardiac morbidity in nonsurgical populations, and may benefit surgical patients. We sought to examine cardiac outcome in patients who continued, compared with those who discontinued, statin therapy after major vascular surgery.

METHODS

Prospectively collected data were examined for an association between statin therapy and perioperative cardiac morbidity in patients undergoing infrarenal aortic surgery. Between January 2001 and December 2003, there were no guidelines for perioperative continuation of statins (discontinuation group, n = 491). From January 2004, guidelines were instituted whereby statin therapy was continued starting as soon as possible after surgery (continuation group, n = 178). The occurrence of cardiac myonecrosis (defined as an increase of cardiac troponin I more than the 99th percentile or 0.2 ng/mL) was analyzed. Intra-cohort (propensity score) and extra-cohort (Lee score) adjustments of the risk were performed.

RESULTS

The median delay between surgery and resumption of statin therapy was 4 days and 1 day in the discontinuation and continuation groups (P < 0.001), respectively. Using propensity score matching for likelihood of preoperative treatment, the odds ratio associated with chronic statin treatment to predict myonecrosis for patients with versus without early postoperative statin resumption (continuation versus discontinuation groups) was 0.38 and 2.1 (relative risk reduction of 5.4; 95% confidence interval: 1.2-25.3, P < 0.001), respectively. The odds ratio after adjustment for the Lee score was 0.38 in the continuation group and 2.1 in the discontinuation group (relative reduction of 5.5; 95% confidence interval: 1.2-26.0, P < 0.001). Postoperative statin withdrawal (>4 days) was an independent predictor of postoperative myonecrosis (OR 2.9, 95% confidence interval 1.6-5.5).

CONCLUSIONS

Discontinuation of statin therapy after major vascular surgery is associated with an increased postoperative cardiac risk, suggesting that statin therapy should be resumed early after major vascular surgery.

Sexual function and obesity

OBJECTIVE

To review the literature on the relationship between obesity and sexual function.

METHOD

A search in the medical literature from 1966 and onwards was carried out through Medline and Embase for publications on obesity, in combination with Medical Subject Heading words related to sexual function and dysfunction.

COMMENTS

Four prospective and seven cross-sectional studies were found describing association between obesity and erectile dysfunction (ED). One cross-sectional study was found describing obesity and female sexual dysfunction (FSD). The prospective studies on ED all demonstrated a direct association and so did five of the seven cross-sectional studies. The single FSD study did not find any relationship. Eight intervention studies on weight loss and sexual difficulties were identified. All included few individuals and results were mixed even if most indicated an increase of sexual activity among both men and women after weight loss intervention.

CONCLUSION

Support for the assumption that obesity is associated with ED was found in both prospective and cross-sectional studies. FSD was not adequately described in the literature and prospective studies are needed here. Results from weight loss intervention studies are less conclusive, but also point toward improvement in sexual dysfunction with reduced weight.

The protective effect of HMG-CoA reductase inhibitors against monocrotaline-induced pulmonary hypertension in the rat might not be a class effect: comparison of pravastatin and atorvastatin

Hydroxymethylglutaryl coenzyme A (HMG-CoA) reductase inhibitors, so called statins, improve endothelial function and exert antiproliferative effects on vascular smooth muscle cells of systemic vessels. This study aimed at comparing the protective effects of two statins, pravastatin and atorvastatin, against monocrotaline (MC)-induced pulmonary hypertension in rats. Pravastatin or atorvastatin (PS or AS, 10 mg/kg per day) or vehicle were given orally for 28 days to Wistar male rats injected or not with MC (60 mg/kg intraperitoneally). At 4 weeks, MC-injected rats developed severe pulmonary hypertension, with an increase in right ventricular pressure (RVP) and right ventricle/left ventricle + septum weight ratio associated with a decrease in acetylcholine- or sodium-nitroprusside-induced pulmonary artery dilation observed in vitro. Hypertensive pulmonary arteries exhibited an increase in medial thickness and endothelial cell apoptosis and a decrease of endothelial nitric oxide synthase (eNOS) expression. MC-rat lungs showed a significant decrease of eNOS (P < 0.01) and increase of cleaved caspase-3 (P < 0.05) expression determined by Western blotting. PS (P = 0.02) but not AS (P = 0.30) significantly limited the development of pulmonary hypertension (RVP in mmHg: 30 +/- 3, 36 +/- 4 vs. 45 +/- 4 and 14 +/- 1 for MC + PS, MC + AS, MC, and control groups, respectively). Both statins significantly reduced MC-induced right ventricle hypertrophy [RV/left ventricular (LV) + S, in mg/g: 0.46 +/- 0.04, 0.39 +/- 0.03, 0.62 +/- 0.05 and 0.29 +/- 0.01 for MC + PS, MC + AS, MC, and control groups, respectively; P < 0.05),and reduced MC-induced thickening (61 +/- 6 microm, 82 +/- 5 microm, 154 +/- 4 microm, and 59 +/- 2 microm for MC + PS, MC + AS, MC, and control groups, respectively; P = 0.01) of small intrapulmonary artery medial wall, with MC + AS still being different from the control group. PS but not AS partially restored acetylcholine-induced pulmonary artery vasodilation in MC rats (E(max)=65 +/- 5%, 49 +/- 6%, 46 +/- 3%, and 76 +/- 4% for MC + PS, MC + AS, MC, and control groups, respectively; P < 0.05 for MC + PS vs. other groups). Both statins prevented apoptosis and restored eNOS expression of pulmonary artery endothelial cells as well as in the whole lung with a more pronounced effect with PS compared with AS. In conclusion, despite its effects on eNOS expression, apoptosis, and medial wall thickening, AS was unable to significantly reduce pulmonary hypertension and to restore endothelium-dependent relaxation, suggesting intermolecular differences between the two HMG-CoA reductase inhibitors in the protection against MC-induced hypertension.