Determinants of endothelial dysfunction and carotid intima???media thickness in combined hyperlipidemia

Predictors of functional and morphological arterial wall properties in coronary artery disease patients with increased lipoprotein (a) levels before and after treatment with proprotein convertase subtilisin-kexin type 9 inhibitors

BACKGROUND

In addition to proatherogenic properties, lipoprotein (a) (Lp(a)) has also pro-inflammatory, antifibrinolytic and prothrombogenic features. The aim of the current study was to identify the predictors of functional and morphological properties of the arterial wall in patients after myocardial infarction and increased Lp(a) levels at the beginning and after treatment with proprotein convertase subtilisin-kexin type 9 (PCSK9) inhibitors.

METHODS

Seventy-six post-myocardial infarction patients with high Lp(a) levels were included in the study. Ultrasound measurements of flow-mediated dilation of brachial artery (FMD), carotid intima-media thickness (c-IMT) and pulse wave velocity (PWV) were performed initially and after 6 months of treatment. At the same time points lipids, Lp(a), inflammatory and hemostasis markers were measured in blood samples.

RESULTS

In linear regression model FMD significantly correlated with age at first myocardial infarction (β = 0.689; p = 0.022), high-sensitivity C-reactive protein (β = -1.200; p = 0.009), vascular cell adhesion protein 1 (VCAM-1) (β = -0.992; p = 0.006), overall coagulation potential (β = 1.428; p = 0.014) and overall hemostasis potential (β = -1.473; p = 0.008). c-IMT significantly correlated with age at first myocardial infarction (β = 0.574; p = 0.033) and Lp(a) (β = 0.524; p = 0.040). PWV significantly correlated with systolic blood pressure (β = 0.332; p = 0.002), tumor necrosis factor alpha (β = 0.406; p = 0.002), interleukin-8 (β = -0.315; p = 0.015) and plasminogen activator inhibitor 1 (β = 0.229; p = 0.031). After treatment FMD reached statistical significance only in univariant analysis with systolic blood pressure (r = -0.286; p = 0.004) and VCAM-1 (r = -0.229; p = 0.024). PWV and c-IMT correlated with age (r = 0.334; p = 0.001 and r = 0.486; p < 0.0001, respectively) and systolic blood pressure (r = 0.556; p < 0.0001 and r = 0.233; p = 0.021, respectively).

CONCLUSIONS

Our results suggest that age, systolic blood pressure, Lp(a) levels and other biochemical markers associated with Lp(a) are predictors of functional and morphological properties of the arterial vessel wall in post-myocardial patients with high Lp(a) levels initially. However, after 6 months of treatment with PCSK9 inhibitors only age and systolic blood pressure seem to be predictors of these properties.

TRIAL REGISTRATION

The protocol for this study was registered with clinicaltrials.gov on November, 3 2020 under registration number NCT04613167.

Smoking and diabetes attenuate beneficial effects of PSCK9 inhibitors on arterial wall properties in patients with very high lipoprotein (a) levels

Background and aims

Elevated lipoprotein (a) (Lp(a)) and low-density lipoprotein cholesterol levels (LDL-C) are significant residual risk factors for cardiovascular events. Treatment with protein convertase subtilisin kexin type 9 (PCSK9) inhibitors reduces the levels of both. Less is known about effects of PCSK9 inhibitors on functional and morphological properties of the arterial wall. The aim of the present study was to determine whether other factors besides decreased LDL-C and Lp(a) are associated with functional (flow-mediated dilation [FMD]) and morphological (carotid intima-media thickness [c-IMT], pulse-wave velocity [PWV]) changes of the arterial wall properties in patients with coronary artery disease (CAD) treated with alirocumab and evolocumab.

Methods

One hundred patients with CAD after myocardial infarction before 55 years and with high Lp(a) were randomised to lipid-lowering therapies without PCSK9 inhibitors (control; N = 31), or with alirocumab 150 mg SC (N = 35) or evolocumab 140 mg SC (N = 34), every 2 weeks. All patients underwent blood sampling for biochemical analyses and ultrasound measurements for FMD, c-IMT and PWV.

Results

There were no significant changes in FMD for the control (10.7% ± 6.6%-11.1% ± 4.4%, p = 0.716) and alirocumab (10.7% ± 5.9%-11.2% ± 5.3%, p = 0.547) groups, while evolocumab promoted significant increase (11.2% ± 6.8%-14.1% ± 6.6%, p < 0.0001). Only in non-smokers and non-diabetics significant improvements in FMD (p < 0.0001) after treatment with PCSK9 inhibitors were observed.

Conclusion

These data show that for patients with CAD and high Lp(a) levels, beneficial effects of PCSK9 inhibitors on the arterial wall properties can be attenuated by specific risk factors, such as smoking and diabetes.

LPA Genotypes and Haplotypes Are Associated with Lipoprotein(a) Levels but Not Arterial Wall Properties in Stable Post-Coronary Event Patients with Very High Lipoprotein(a) Levels

Lipoprotein(a) [Lp(a)] levels are an independent risk factor for coronary artery disease (CAD). Two single-nucleotide polymorphisms (rs10455872, rs3798220) and number of KIV-2 repeats in the gene encoding Lp(a) (LPA) are associated with Lp(a) and CAD. Our aim was to investigate whether in patients with stable CAD and high Lp(a) levels these genetic variants are associated with increased Lp(a) and arterial wall properties. Blood samples underwent biochemical and genetic analyses. Ultrasound measurements for the functional and morphological properties of arterial wall were performed. Genotypes of rs10455872 and haplotypes AT and GT showed significant association with Lp(a) levels. Patients with GG showed significantly higher Lp(a) levels compared with those with AG genotype (2180 vs. 1391 mg/L, p = 0.045). Patients with no AT haplotype had significantly higher Lp(a) compared to carriers of one AT haplotype (2158 vs. 1478 mg/L, p = 0.023) or two AT haplotypes (2158 vs. 1487 mg/L, p = 0.044). There were no significant associations with the properties of the arterial wall. Lp(a) levels significantly correlated also with number of KIV-2 repeats (r = -0.601; p < 0.0001). In our patients, these two LPA polymorphisms and number of KIV-2 repeats are associated with Lp(a), but not arterial wall properties.

Influence of trimetazidine and ranolazine on endothelial function in patients with ischemic heart disease

OBJECTIVE

Endothelial dysfunction is an independent predictor of atherosclerosis progression and cardiovascular events in patients with ischemic heart disease. Ranolazine and trimetazidine are novel drugs that reduce angina symptoms in the above-mentioned patients. The aim of this study was to compare the effects of ranolazine and trimetazidine on flow-mediated (FMD) and nitroglycerine-induced (GTN) dilation of the brachial artery.

METHODS

In a prospective, double-blind study, 56 men between 32 and 65 years of age with chronic ischemic heart disease were randomized and subjected to 12 weeks of treatment with either trimetazidine (35 mg twice daily) or ranolazine. Ranolazine was administered at a dose of 375 mg twice daily for 4 weeks and was increased to 500 mg twice daily for the rest of the study. FMD and GTN were measured using high-resolution ultrasound before and after treatment.

RESULTS

FMD increased from 3.5±7.4 to 13.8±9.4% (P<0.013; 294%) in the trimetazidine group and from 2.4±4.3 to 9.5±7.7% (P<0.037; 296%) in the ranolazine group, with no difference between the groups (P=0.444). GTN increased from 16.1±9.2 to 21.2±19.3% (P<0.022; 32%) in the trimetazidine group and from 13.8±9.6 to 21.7±13.7% (P<0.006; 57%) in the ranolazine group, with no difference between the groups (P=0.309).

CONCLUSION

Both trimetazidine and ranolazine led to an improvement in FMD and GTN of the brachial artery in patients with ischemic heart disease, with no statistically significant difference between the groups.

The role of tissue factor pathway inhibitor in atherosclerosis and arterial thrombosis

Tissue factor pathway inhibitor (TFPI) is the main inhibitor of tissue factor (TF)-mediated coagulation. In atherosclerotic plaques TFPI co-localizes with TF, where it is believed to play an important role in attenuating TF activity. Findings in animal models such as TFPI knockout models and gene transfer models are consistent on the role of TFPI in arterial thrombosis as they reveal an active role for TFPI in attenuating arterial thrombus formation. In addition, ample experimental evidence exists indicating that TFPI has inhibitory effects on both smooth muscle cell migration and proliferation, both which are recognized as important pathological features in atherosclerosis development. Nonetheless, the clinical relevance of these antithrombotic and atheroprotective effects remains unclear. Paradoxically, the majority of clinical studies find increased instead of decreased TFPI antigen and activity levels in atherothrombotic disease, particularly in atherosclerosis and coronary artery disease (CAD). Increased TFPI levels in cardiovascular disease might result from complex interactions with established cardiovascular risk factors, such as hypercholesterolemia, diabetes and smoking. Moreover, it is postulated that increased TFPI levels reflect either the amount of endothelial perturbation and platelet activation, or a compensatory mechanism for the increased procoagulant state observed in cardiovascular disease. In all, the prognostic value of plasma TFPI in cardiovascular disease remains to be established. The current review focuses on TFPI in clinical studies of asymptomatic and symptomatic atherosclerosis, coronary artery disease and ischemic stroke, and discusses potential atheroprotective actions of TFPI.

A spontaneous, double-blind, double-dummy cross-over study on the effects of daily vardenafil on arterial stiffness in patients with vasculogenic erectile dysfunction

BACKGROUND

It is known that the incidence of endothelial dysfunction in patients with vascular erectile dysfunction (ED) is increased. The effects of daily vardenafil on endothelial function and arterial stiffness in patients with erectile dysfunction (ED) have never been investigated.

METHODS

20 men complaining vascular ED (mean IIEF5=12 ± 6 and peak systolic velocity-PSV=24 ± 2 cm/s) were enrolled in a 4-week, randomized, double-blind, double-dummy, crossover study (mean age 59 ± 11) and received either vardenafil 10mg daily or 20mg on-demand with a two-week washout interval. Primary endpoints were variation from baseline of reactive hyperemia (RH) and augmentation index (AI) calculated by fingertip peripheral arterial tonometry (PAT) device. Secondary endpoints were variations of IIEF-5 and SEP3 scores from baseline and plasma surrogate markers of endothelial function, i.e. endothelin-1 (ET-1) and adrenomedullin (ADM).

RESULTS

Patients who took daily vardenafil (vs. on-demand) reported significant (P<0.01) improvements in arterial stiffness as evaluated by AI and reduction of plasma ADM levels (p<0.05) but no improvement in average RH. When corrected for heart rate, ADM showed a strong direct relationship with AI (r(2)=0.22; p<0.005). The proportion of patients with an IIEF5 score of ≥ 22 or in SEP3 percentage of success rates were similar. Each treatment resulted in significantly greater IIEF5 scores (p<0.001) and better SEP3 response rates (p<0.0001) compared with baseline.

CONCLUSIONS

We demonstrated that daily vardenafil improves arterial stiffness and erectile function measurements in men with severe vasculogenic ED. This effect may be mediated, at least in part, by a reduction in ADM circulating levels.

Apolipoprotein B, non-HDL cholesterol and LDL cholesterol for identifying individuals at increased cardiovascular risk

BACKGROUND

To compare apolipoprotein B (apoB), non-high-density lipoprotein-cholesterol (non-HDL-c) and low-density lipoprotein-cholesterol (LDL-c) for identifying individuals with a deteriorated cardiovascular (CV) risk profile, including a panel of subclinical atherosclerosis measurements and prevalent cardiovascular disease (CVD) in a Dutch population-based cohort.

METHODS

Clinical and biochemical measurements and a panel of noninvasive parameters of subclinical atherosclerosis were determined in 1517 individuals, aged 50-70 years.

RESULTS

Both men and women with increasing levels of apoB and non-HDL-c were more obese, had higher blood pressure and fasting glucose levels, and a more atherogenic lipid profile. Furthermore, compared to the reference group (composed of those with apoB, non-HDL-c and LDL-c levels in the bottom quartiles), participants with high apoB and high non-HDL-c levels had a lower ankle-brachial index at rest (-3.5% and -3.1%, respectively) and after exercise (-6.3% and -4.7%, respectively), a thicker near wall (+4.8% and +4.2%, respectively), far wall (both +6.2%), and mean intima-media thickness (+5.7% and +5.3%, respectively) and more plaques (+54.2% and +54.3%, respectively). In addition, they also showed increased stiffness parameters (e.g. pulse wave velocity both +3.6%). Less clear differences in CV risk profile and subclinical atherosclerosis parameters were observed when participants were stratified by LDL-c level. Furthermore, apoB but not LDL-c detected prevalent CVD, and non-HDL-c only detected prevalent CVD in men. The discriminatory power for prevalent CVD expressed as area under the receiver operating characteristic curve was 0.60 (P < 0.001) for apoB, 0.57 (P = 0.001) for non-HDL-c and 0.54 (P = 0.108) for LDL-c.

CONCLUSION

Our data support the use of first apoB and secondly non-HDL-c above LDL-c for identifying individuals from the general population with a compromised CV phenotype.

E-selectin and TFPI are associated with carotid intima-media thickness in stable IHD patients: the baseline findings of the MIAMI study

OBJECTIVE

MIAMI was a prospective multicenter clinical study designed to investigate the relationship between changes in carotid intima-media thickness (C-IMT) and those in the levels of circulating markers of inflammation, thrombosis and endothelial dysfunction. The study was performed in a group of stable coronary patients treated for two years with a moderate dosage of atorvastatin (20mg/day). In this paper the cross-sectional relationship between C-IMT and the same circulating markers of inflammation, thrombosis and endothelial dysfunction measured at baseline was investigated.

METHODS

Eighty-five subjects that had not used statins for at least two months were enrolled in the study. At time of enrollment, the levels of vascular cell adhesion molecule-1 (VCAM-1), intracellular adhesion molecule-1 (ICAM-1), E-selectin, interleukin (IL)-6, IL-8, tumor necrosis factor (TNF)-alpha, high-sensitivity C-reactive protein (hs-CRP), tissue factor (TF), tissue factor pathway inhibitor (TFPI), von Willebrand factor (vWF), fibrinogen, total cholesterol (TC), high-density lipoprotein (HDL) and low-density lipoprotein (LDL), and triglycerides were measured, in parallel with C-IMT assessment.

RESULTS

In cross-sectional analyses, markers of endothelial perturbation (i.e. E-selectin) and TFPI were more strongly correlated with arherosclerotic burden than markers of inflammation. The baseline picture in this study indicates that E-selectin and TFPI are linked with atherosclerotic burden.

Effects of weight loss from a very-low-carbohydrate diet on endothelial function and markers of cardiovascular disease risk in subjects with abdominal obesity

BACKGROUND

The effects of a very-low-carbohydrate, high-saturated-fat weight-loss diet (LC) on brachial artery flow-mediated dilatation (FMD) and markers of endothelial function are unknown.

OBJECTIVE

The effect of an LC on markers of endothelial function and cardiovascular disease (CVD) risk was compared with that of an isocaloric high-carbohydrate, low-saturated-fat diet (HC).

DESIGN

FMD and markers of endothelial function (n = 70) and CVD risk were measured before and after 8 wk of weight loss. Ninety-nine subjects aged 50.0 +/- 8.3 y with a body mass index (in kg/m2) of 33.7 +/- 4.1 completed the study.

RESULTS

Mean (+/-SD) FMD did not change significantly (P = 0.55) with either diet. Pulse wave velocity improved with both diets (P < 0.01). Endothelial markers, E- and P selectin, intracellular and cellular-adhesion molecule-1, tissue-type plasminogen activator, and plasminogen activator inhibitor-1 decreased (P < 0.001), with no diet effect. Adiponectin did not change significantly. More weight (P = 0.05 for diet x time interaction) and more abdominal fat mass (P = 0.05 for diet x time interaction) were lost with the LC than with the HC. LDL cholesterol decreased more with the HC than with the LC (P < 0.05, time x diet), and C-reactive protein decreased more with the HC than with the LC (P < 0.05 for diet x time interaction). Homocysteine increased more with the LC (P < 0.01 for diet x time interaction). Folate decreased with the LC and increased with the HC (P < 0.05, time; P < 0.001 for diet x time interaction).

CONCLUSION

An LC does not impair FMD. We observed beneficial effects of both diets on most of the CVD risk factors measured. This trial was registered with the Australian Clinical Trials Registry as ACTR N0 12606000203550.

Carotid intima-media thickness and markers of inflammation, endothelial damage and hemostasis

BACKGROUND

Different soluble molecules involved in inflammation, endothelial damage, or hemostasis are recognized as potential cardiovascular risk markers. Studies to assess the role of these markers in the atherosclerotic process by evaluating their relationship to carotid intima-media thickness (C-IMT) tend to provide contrasting results.

PURPOSE

To perform a review of studies addressing the association between C-IMT and soluble markers and to investigate whether the observed inconsistencies could be explained by the characteristics of the patients included in different studies, for example prevalence of atherosclerotic disease (atherosclerotic burden), gender, age, or occurrence of specific vascular risk factors (VRFs).

DATA SOURCES

PubMed and Embase (January 1990 to March 2006).

STUDY SELECTION

Articles in English reporting original cross-sectional studies.

DATA EXTRACTION

Two authors independently extracted data on study design, population, sample size, ultrasonic methodology, and statistical approach.

DATA SYNTHESIS

Despite the marked heterogeneity of results presented in the literature, meta-analysis established that studies showing positive associations between C-IMT and plasma levels of C-reactive protein (CRP) or fibrinogen are in the majority. Funnel plot analyses suggested the absence of an important publication bias. Data on the relationships between C-IMT and other soluble markers are by contrast scanty, contradictory, or unconfirmed by multivariate (as opposed to univariate) analyses, and the freedom from publication bias here cannot be vouched for. The degree of atherosclerotic burden in the population studied does not account for the heterogeneity of findings reported. Gender, noninsulin-dependent diabetes mellitus (NIDDM) and hypercholesterolemia influence the association between C-IMT and CRP. Blood pressure and hypercholesterolemia influence the association between C-IMT and fibrinogen. For all the other soluble markers considered, the number of groups was too small for this kind of statistical considerations.

LIMITATIONS

Heterogeneity in ultrasound methodologies and in statistical approach limited comparability between studies. For most soluble markers, publication bias of positive results cannot be excluded.

CONCLUSIONS

Only CRP and fibrinogen seem to be unequivocally related to C-IMT. For all the other soluble markers considered, no clear-cut conclusions can be drawn.

Comparison of atorvastatin versus fenofibrate in reaching lipid targets and influencing biomarkers of endothelial damage in patients with familial combined hyperlipidemia

Statins and fibrates have different effects on lipid abnormalities of familial combined hyperlipidemia (FCHL); thus, the selection of the first-line drug is troublesome. We evaluated to what extent monotherapy with a potent statin is more effective than fibrate in reaching the recommended lipid targets in FCHL. Fifty-six patients were randomized to receive optimal dosage of atorvastatin (n = 27) or 200 mg/d micronized fenofibrate (n = 29) for 24 weeks. To reach the optimal dosage, atorvastatin was up-titrated at each follow-up visit if low-density lipoprotein (LDL) cholesterol >130 mg/dL (>100 mg/dL in patients with coronary or cerebrovascular disease). The effects of fenofibrate and atorvastatin on lipoprotein fractions as well as on plasma levels of endothelin-1 (ET-1) and adrenomedullin (AM) were also evaluated. At end of trial, a greater proportion of patients on atorvastatin (average dosage, 20.8 mg/d) reached lipid targets in comparison with those on fenofibrate (64% vs 32.1%, P = .02). Atorvastatin was significantly more effective in reducing total cholesterol, LDL cholesterol, apolipoprotein B, and non-high-density lipoprotein (HDL) cholesterol. Conversely, triglycerides decreased and HDL increased more during fenofibrate. Nevertheless, atorvastatin produced a marked reduction in very low-density lipoprotein and very low-density lipoprotein remnants. Atorvastatin lowered all LDL subtypes, although fenofibrate appeared to be more effective on denser LDL. Compared with 43 normolipemic controls, FCHL patients presented increased baseline plasma levels of ET-1 (P = .007) but not of AM. Fenofibrate, but not atorvastatin, significantly lowered ET-1 levels by 16.7% (P < .05). Neither drug significantly affected plasma concentrations of AM. In summary, although fenofibrate showed superiority in raising HDL and reducing ET-1, atorvastatin was more effective in reaching lipid targets in FCHL so that it can be proposed as the first-line option in the management of this atherogenic hyperlipidemia.

The apoB/apoA-I ratio: a strong, new risk factor for cardiovascular disease and a target for lipid-lowering therapy--a review of the evidence

During the last several years interest has focused on the importance of the lipid-transporting apolipoproteins--apoB transports all potentially atherogenic very low-density lipoprotein (VLDL), intermediate-density lipoprotein (IDL) and LDL particles, and apoA-I transports and acts as the major antiatherogenic protein in the HDL particles. The evidence for the apoB/apoA-I ratio being a strong, new risk factor for cardiovascular (CV) disease and a target for lipid-lowering therapy is reviewed. Results from clinical prospective studies and lipid-lowering trials in healthy subjects and in patients with different clinical manifestations of atherosclerosis are reported. Risk of nonfatal and fatal myocardial infarction and stroke, and manifestations of atherosclerosis documented by angiographic, ultrasound and other techniques has been related to conventional lipids and apolipoproteins (apo). The cholesterol balance determined as the apoB/apoA-I ratio has repeatedly been shown to be a better marker than lipids, lipoproteins and lipid ratios. The results indicate that the apoB/apoA-I ratio is a simple, accurate and new risk factor for CV disease--the lower the apoB/apoA-I ratio, the lower is the risk. Guidelines should be developed in order to recognize the important clinical risk information embedded in the apoB/apoA-I ratio.