The effects of dyslipidemia on left ventricular systolic function in patients with stable angina pectoris

Relationship between Oxidative Stress and Left Ventricle Markers in Patients with Chronic Heart Failure

Oxidative stress is proposed in the literature as an important player in the development of CHF and correlates with left ventricle (LV) dysfunction and hypertrophy in the failing heart. In this study, we aimed to verify if the serum oxidative stress markers differ in chronic heart failure (CHF) patients' groups depending on the LV geometry and function. Patients were stratified into two groups according to left ventricular ejection fraction (LVEF) values: HFrEF (<40% (n = 27)) and HFpEF (≥40% (n = 33)). Additionally, patients were stratified into four groups according to LV geometry: NG-normal left ventricle geometry (n = 7), CR-concentric remodeling (n = 14), cLVH-concentric LV hypertrophy (n = 16), and eLVF-eccentric LV hypertrophy (n = 23). We measured protein (protein carbonyl (PC), nitrotyrosine (NT-Tyr), dityrosine), lipid (malondialdehyde (MDA), oxidizes (HDL) oxidation and antioxidant (catalase activity, total plasma antioxidant capacity (TAC) markers in serum. Transthoracic echocardiogram analysis and lipidogram were also performed. We found that oxidative (NT-Tyr, dityrosine, PC, MDA, oxHDL) and antioxidative (TAC, catalase) stress marker levels did not differ between the groups according to LVEF or LV geometry. NT-Tyr correlated with PC (r_s = 0.482, p = 0.000098), and oxHDL (r_s = 0.278, p = 0.0314). MDA correlated with total (r_s = 0.337, p = 0.008), LDL (r_s = 0.295, p = 0.022) and non-HDL (r_s = 0.301, p = 0.019) cholesterol. NT-Tyr negatively correlated with HDL cholesterol (r_s = -0.285, p = 0.027). LV parameters did not correlate with oxidative/antioxidative stress markers. Significant negative correlations were found between the end-diastolic volume of the LV and the end-systolic volume of the LV and HDL-cholesterol (r_s = -0.935, p < 0.0001; r_s = -0.906, p < 0.0001, respectively). Significant positive correlations between both the thickness of the interventricular septum and the thickness of the LV wall and the levels of triacylglycerol in serum (r_s = 0.346, p = 0.007; r_s = 0.329, p = 0.010, respectively) were found. In conclusions, we did not find a difference in serum concentrations of both oxidant (NT-Tyr, PC, MDA) and antioxidant (TAC and catalase) concentrations in CHF patients' groups according to LV function and geometry was found. The geometry of the LV could be related to lipid metabolism in CHF patients, and no correlation between oxidative/antioxidant and LV markers in CHF patients was found.

Lipid Levels and New-Onset Atrial Fibrillation in Patients with Acute Myocardial Infarction

AIM

In acute myocardial fraction (AMI) patients, the association between lipid parameters and new-onset atrial fibrillation (NOAF) remains unclear due to limited evidence.

METHODS

A total of 4282 participants free from atrial fibrillation (AF) at baseline were identified in Beijing Friendship Hospital. Fasting levels of total cholesterol (TC), triglycerides (TG), low-density lipoprotein cholesterol (LDL-C), and high-density lipoprotein cholesterol (HDL-C) were measured at baseline. The study population was stratified based on tertiles of lipid profile and lipid ratios. Incidence of NOAF was observed at the follow-up visits. The associations between different lipid parameters and the incidence of NOAF were assessed by multivariate Cox regression analysis.

RESULTS

Over a median follow-up period of 42.0 months (IQR: 18.7, 67.3 months), 3.1% (N=132) AMI patients developed NOAF. After multivariable adjustment, higher TC (hazard ratios (HR): 0.205, 95% confidence intervals (CI): 0.061-0.696) levels were inversely associated with NOAF development. However, higher HDL-C (HR: 1.892, 95% CI: 1.133-3.159) levels were positively associated with NOAF development. LDL-C levels, TG levels, non-HDL-C levels, and lipid ratios showed no association with NOAF development.

CONCLUSION

TC levels were inversely associated with incidence of NOAF; this was mainly reflected in the subgroups of male gender and older patients (65 years or older). HDL-C levels were positively associated with incidence of NOAF; this was mainly reflected in the subgroups of male gender and younger patients (age ＜65 years). There was no significant association of NOAF with LDL-C, TG, or non-HDL-C levels.

Endogenous Cardiotonics: Search And Problems

Medicinal preparations currently used for the treatment of patients with chronic cardiac failure involve those that reduce the heart load (vasodilators, diuretics, beta-blockers, and angiotensin-converting enzyme (ACE) inhibitors). Cardiotonic drugs with the cAMP-dependent mechanism are unsuitable for long-term administration due to the intensification of metabolic processes and an increase in the oxygen demand of the myocardium and all tissues of the body. For many years, digoxin has remained the only preparation enhancing the efficiency of myocardial performance. The detection of digoxin and ouabain in intact animals has initiated a search for other compounds with cardiotonic activity. The review summarizes current data on the effect exerted on the heart performance by endogenous compounds, from simple, such as NO and CO, to steroids, fatty acids, polypeptides, and proteins. Controversial questions and problems with the introduction of scientific achievements into clinical practice are discussed. The results obtained by the authors and their colleagues after many years of studies on the cardiotropic properties of serum lipoproteins are also reported. The experimentally established cardiotonic activity of apoprotein A-1, which is accompanied by a decrease in the relative consumption of oxygen, maybe of great interest.

Role of apolipoprotein E in electronegative low-density lipoprotein-induced mitochondrial dysfunction in cardiomyocytes

OBJECTIVE

L5, a highly electronegative subtype of low-density lipoprotein (LDL), is likely associated with the development of atherosclerosis and cardiovascular diseases. Normal LDL is composed mainly of apolipoprotein (Apo) B, but L5 has additional proteins such as ApoE. We previously demonstrated that L5 induces endothelial cell senescence by increasing mitochondrial reactive oxygen species. In the present study, we examined the effect of L5 on mitochondrial function in cardiomyocytes.

METHODS

We used the Seahorse XF24 extracellular flux analyzer to examine the effect of L5 and its components on mitochondrial energy production. The effects of L5 on mitochondrial morphology were examined by immunofluorescence using MitoTracker Green FM and the corresponding probes in H9c2 cardiomyoblasts. Mitochondrial permeability was assessed by using a calcium-induced swelling assay with a voltage-dependent anion-selective channel (VDAC) inhibitor to determine VDAC-dependence both in vitro and in vivo. L5 without ApoE, referred to as △L5, was used to clarify the role of ApoE in L5-induced mitochondrial dysfunction.

RESULTS

L5 not only significantly decreased basal (P < 0.05) and maximal respiration (P < 0.01) but also reduced spare respiratory capacity (P < 0.01) in H9c2 cells. Additionally, L5 caused phosphorylation of Drp1 and mitochondrial fission. Recombinant ApoE mimicked the mitochondrial effects of L5, but △L5 did not cause similar effects. After entering cells, ApoE on L5 colocalized with mitochondrial VDAC and caused mitochondria swelling both in vitro and in vivo. This effect was also seen with recombinant ApoE but not △L5.

CONCLUSIONS

ApoE may play an important role in electronegative LDL-induced mitochondrial dysfunction through the opening of the mitochondrial permeability transition pore via the interaction of ApoE and VDAC.

Factors influencing left ventricular ejection fraction in patients with coronary microvascular disease and obstructive coronary artery disease

Objective

The aim of our research was to evaluate the relationship involving left ventricular ejection fraction, low density lipoprotein, B-type natriuretic peptide, Troponin I and coronary flow reserve, and to determine the predictors of left ventricular ejection fraction in patients with coronary microvascular disease and obstructive coronary artery disease, and in patients with coronary microvascular disease.

Results

The mean age was 58.5 ± 12.5 years. In patients with obstructive coronary disease and coronary microvascular disease we found low density lipoprotein-c had significant inverse relationship with left ventricular ejection fraction, left ventricular ejection fraction also had significant negative relationship with B-type natriuretic peptide, and Troponin-I. While a significant direct relationship turned out to be observed linking left ventricular ejection fraction with coronary flow reserve. Left ventricular ejection fraction had significant negative relationship with low density lipoprotein, and B-type natriuretic peptide in patients with obstructive coronary artery disease only. Age, blood pressure, lipid levels, red cell distribution width, glycated hemoglobin, symptoms, New York heart association classification, alcohol drinking, hypertension, diabetes mellitus, troponin levels and B-type natriuretic peptide were the predictors for left ventricular ejection fraction in coronary microvascular disease patients.

Cardioprotective Effects of High-Density Lipoprotein Beyond its Anti-Atherogenic Action

High-density lipoprotein cholesterol (HDL-C) has been identified as a powerful independent negative predictor of cardiovascular disease. The beneficial effect of HDL is largely attributable to its key role in reverse cholesterol transport, whereby excess cholesterol in the peripheral tissues is transported to the liver, reducing the atherosclerotic burden. However, mounting evidence indicates that HDL also has pleiotropic properties, such as anti-inflammatory, anti-oxidative, and vasodilatory properties, which may contribute in reducing the incidence of heart failure. Actually, previous data from clinical and experimental studies have suggested that HDL exerts cardioprotective effects irrespective of the presence/absence of coronary artery disease. This review summarizes the currently available evidence regarding beneficial effects of HDL on the heart beyond its anti-atherogenic property. Understanding the mechanisms of cardiac protection by HDL will provide new insight into the underlying mechanism and therapeutic strategy for heart failure.

Association Between Blood Lipid Profiles and Atrial Fibrillation: A Case-Control Study

Background

Dyslipidemia is the most frequent comorbidity in patients with cardiovascular disease. However, studies examining the relationship between blood lipid profiles and AF have produced inconsistent results.

Material/Methods

A total of 651 patients were enrolled into 3 groups: Healthy controls (n=64), Paroxysmal AF (PAF; n=270), and Continuous AF (CAF; n=317). All enrolled patients underwent routine baseline 12-lead electrocardiography (ECG) and 24-h dynamic ECG along with blood testing, which included the following: complete metabolic panel, hepatic function, renal function, circulating thyroxine, fasting high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C), triglycerides (TG), and total cholesterol (TC).

Results

Patients with AF had significantly higher levels of triglycerides (TG), lower levels of LDL-C-c, and lower levels of HDL-C (p<0.05). TC (OR 0.979, p<0.9247) and TG (OR 0.945, p<0.6496) were negatively and linearly associated with PAF, while TG (OR 0.807, p=0.2042), LDL-C (OR 0.334, p=0.0036), and HDL-C (OR 0.136, p=0.0002) were negatively and linearly associated with CAF.

Conclusions

Compared to healthy controls, patients with AF had lower blood lipid levels, especially LDL-c and HDL-c levels. Hypolipoproteinemia may increase patient susceptibility to developing AF.

Cholesterol remnants and triglycerides are associated with decreased myocardial function in patients with type 2 diabetes

BACKGROUND

Recently, genetic studies have suggested a causal relationship between cholesterol remnants and ischemic heart disease. We aimed to determine whether cholesterol remnants and its marker, triglyceride levels, are associated with cardiac function as determined by sensitive echocardiographic measures in a population of patients with type 2 diabetes.

METHODS

Comprehensive echocardiography including 2D-speckle tracking echocardiography was performed on a representative sample of 924 patients with type 2 diabetes-730 of whom were treated with statins. These were recruited from two large secondary care centers.

RESULTS

In multivariable analyses, triglycerides and cholesterol remnants were not associated with left ventricular ejection fraction, but with subtle measures of systolic function, including global longitudinal strain by speckle tracking and longitudinal displacement by tissue Doppler echocardiography: global longitudinal strain [0.33 % (0.14), p = 0.02 per doubling in cholesterol remnants and 0.28 % (0.13), p = 0.03 per doubling in triglyceride levels] and with longitudinal displacement [-0.25 mm (0.10), p = 0.01 per doubling in cholesterol remnants and -0.25 mm (0.09), p = 0.005 per doubling in triglyceride levels]. Subgroup analyses of patients receiving statin therapy and patients without known heart disease revealed similar results, but the association was not present in patients with known heart disease.

CONCLUSION

In patients with type 2 diabetes, subtle decrease in left ventricular function is present with increasing levels of cholesterol remnants and triglyceride levels indicating an effect of these on cardiac function that is not detectable by conventional echocardiography.

Protective Effects of HDL Against Ischemia/Reperfusion Injury

Several lines of evidence suggest that, besides being a strong independent predictor of the occurrence of primary coronary events, a low plasma high density lipoprotein (HDL) cholesterol level is also associated with short- and long-term unfavorable prognosis in patients, who have recovered from a myocardial infarction, suggesting a direct detrimental effect of low HDL on post-ischemic myocardial function. Experiments performed in ex vivo and in vivo models of myocardial ischemia/reperfusion (I/R) injury have clearly shown that HDL are able to preserve cardiac function when given before ischemia or at reperfusion; the protective effects of HDL against I/R injury have been also confirmed in other tissues and organs, as brain and hind limb. HDL were shown to act on coronary endothelial cells, by limiting the increase of endothelium permeability and promoting vasodilation and neoangiogenesis, on white blood cells, by reducing their infiltration into the ischemic tissue and the release of pro-inflammatory and matrix-degrading molecules, and on cardiomyocytes, by preventing the activation of the apoptotic cascade. Synthetic HDL retains the cardioprotective activity of plasma-derived HDL and may become a useful adjunctive therapy to improve clinical outcomes in patients with acute coronary syndromes or undergoing coronary procedures.

Serum lipids and cardiac function correlate with nitrotyrosine and MMP activity in coronary artery disease patients

AIMS

Peroxynitrite-matrix metalloproteinase (MMP) signalling has been shown to contribute to myocardial ischaemia/reperfusion injury and heart failure and to be influenced by hyperlipidaemia in preclinical models. Therefore, here we investigated the correlation between the markers of peroxynitrite-MMP signalling and hyperlipidaemia in patients with significant coronary stenosis.

METHODS

Five minutes before percutaneous coronary intervention (PCI), arterial blood samples were collected from 36 consecutive patients with coronary artery disease (CAD) selected for elective PCI.

RESULTS

Serum nitrotyrosine positively correlated with MMP-9 activity (r = 0·54, P = 0·01), but not with MMP-2 activity. Nitrotyrosine positively correlated with total (r = 0·58; P < 0·01) and LDL cholesterol (r = 0·55; P < 0·01), serum triglyceride (r = 0·47; P < 0·05), and creatinine (r = 0·42; P < 0·05) and negatively correlated with HDL cholesterol (r = -0·46; P < 0·05) and with left ventricular ejection fraction (LVEF; r = -0·55; P < 0·05), respectively. MMP-2 activity correlated positively with total (r = 0·55; P < 0·05) and LDL cholesterol (r = 0·45; P < 0·05). In statin-treated patients, a significantly reduced serum nitrotyrosine was found as compared to statin naives; however, MMP activities and serum cholesterol levels were not different. MMP-9 activity correlated with urea nitrogen (r = 0·42; P < 0·05) and LVEF (r = -0·73; P < 0·01). Serum creatinine correlated negatively with LVEF (r = -0·50, P < 0·01).

CONCLUSIONS

This is the first demonstration that (i) serum nitrotyrosine correlates with MMP-9 activity, (ii) lipid parameters correlate with nitrotyrosine and MMP-2 activity, (iii) myocardial function correlates with creatinine, nitrotyrosine and MMP-9 activity, and (iv) creatinine correlates with nitrotyrosine and urea nitrogen with MMP-9 activity in patients with CAD. Studying the biomarkers of peroxynitrite-MMP pathway in large prospective trials may reveal their diagnostic avails.

Systemic hemodynamics in young adults with the metabolic syndrome: the Cardiovascular Risk in Young Finns Study

OBJECTIVE

We conducted the present study to examine associations of three different metabolic syndrome (MetS) definitions and their components to arterial stiffness, systemic vascular resistance, and left ventricular function at population level. In addition, the objective of the study was to examine associations of spontaneous recovery from MetS over 6 years' follow-up to systemic hemodynamics.

METHODS

The study population consisted of 1,741 Finnish young adults (aged 30-45 years) who had complete MetS risk factor and hemodynamic data available at 2007. Associations of spontaneous recovery from MetS to systemic hemodynamics was studied on a subpopulation of 1,391 subjects who had also complete MetS risk factor data available at 2001. Hemodynamic measurements were performed using a whole-body impedance cardiography device.

RESULTS

MetS and increasing number of MetS components were associated with lower stroke index (P < 0.001) and higher systemic vascular resistance index (P < 0.005) and arterial pulse wave velocity (P < 0.005). In MetS persistent group, stroke index was lower (P = 0.024), and pulse wave velocity was higher (P = 0.003) compared to MetS recovery group.

CONCLUSION

All current MetS definitions identify young adults with altered systemic hemodynamics, and recovery from MetS is associated with a favorable hemodynamic profile.

Cross-sectional relations of lipid concentrations to left ventricular structural attributes

Although previous investigations reported on the associations of lipid concentrations with left ventricular remodeling in specific subpopulations, few data exist on these associations in a community-based sample of subjects without cardiovascular disease. In this study, 3,554 Framingham Heart Study participants (mean age 47 years, 53% women) without preexisting clinical cardiovascular disease were examined, and no meaningful associations of high-density lipoprotein cholesterol or non-high-density lipoprotein cholesterol with echocardiographic indexes of left ventricular structure were observed. In conclusion, these data do not support an independent association between lipid concentrations and left ventricular structure.

Relations of lipid concentrations to heart failure incidence: the Framingham Heart Study

BACKGROUND

The relations of lipid concentrations to heart failure (HF) risk have not been elucidated comprehensively.

METHODS AND RESULTS

In 6860 Framingham Heart Study participants (mean age, 44 years; 54% women) free of baseline coronary heart disease, we related high-density lipoprotein cholesterol (HDL-C) and non-HDL-C to HF incidence during long-term follow-up, adjusting for clinical covariates and myocardial infarction at baseline and updating these at follow-up examinations. We evaluated dyslipidemia-specific population burden of HF by calculating population attributable risks. During follow-up (mean of 26 years), 680 participants (49% women) developed HF. Unadjusted HF incidence in the low (<160 mg/dL) versus high (> or =190 mg/dL) non-HDL-C groups was 7.9% and 13.8%, respectively, whereas incidence in the high (> or =55 [men], > or =65 [women] mg/dL) versus low (<40 [men], <50 [women] mg/dL) HDL-C groups was 6.1% and 12.8%, respectively. In multivariable models, baseline non-HDL-C and HDL-C, modeled as continuous measures, carried HF hazards (confidence intervals) of 1.19 (1.11 to 1.27) and 0.82 (0.75 to 0.90), respectively, per SD increment. In models updating lipid concentrations every 8 years, the corresponding hazards (confidence intervals) were 1.23 (1.16 to 1.31) and 0.77 (0.70 to 0.85). Participants with high baseline non-HDL-C and those with low HDL-C experienced a 29% and 40% higher HF risk, respectively, compared with those in the desirable categories; the population attributable risks for high non-HDL-C and low HDL-C were 7.5% and 15%, respectively. Hazards associated with non-HDL-C and HDL-C remained statistically significant after additional adjustment for interim myocardial infarction.

CONCLUSIONS

Dyslipidemia carries HF risk independent of its association with myocardial infarction, suggesting that lipid modification may be a means for reducing HF risk.

Long-term effects of antilipidaemic therapy on left ventricular function in patients with dyslipidaemia: multigated radionuclide ventriculography study

AIM

It has been reported that dyslipidaemia impairs left ventricular systolic (LVs) and diastolic (LVd) functions, irrespective of atherogenic effects, in the setting of coronary artery disease. The aim of the present study was to evaluate the effects of anti-lipidaemic therapy on LVs and LVd functions by means of multigated radionuclide ventriculography (RNV) in subjects with signs of dyslipidaemia and with preserved left ventricular function.

METHODS

Eighteen patients with dyslipidaemia (eight men, 10 women, mean age 50+/-10 years) were included in the study. While the clinical examination and treadmill exercise test results were normal in all patients, low-density lipoprotein levels exceeded 160 mg . dl. Patients with medical conditions including coronary artery disease, hypertension, diabetes, cardiomyopathy and valvular heart disease which would influence left ventricular function were excluded from the study. RNV was performed in all subjects, taking into account the best septal position to differentiate the left ventricle from the right ventricle. The following parameters were calculated: ejection fraction, peak ejection rate (PER), time to peak ejection (TPER), a ejection rate (aER), a ejection fraction (aEF), Peak filling rate (PFR), time to peak filling rate (TPFR), a filling rate (aFR), a filling fraction (aFF).

RESULTS

The low-density lipoprotein value decreased and the high-density lipoprotein value increased after statin therapy (P<0.001 and P<0.003, respectively). PER, aER and aFF significantly increased and TPER decreased as a consequence of statin therapy (respectively, P<0.05, P<0.05, P<0.05 P<0.05).

CONCLUSION

Anti-lipidaemic therapy is effective in dyslipidaemic patients. RNV is a useful and non-invasive method for monitoring changes in ventricular function following anti-lipidaemic treatment strategies.

The Association Between Cholesterol and Mortality in Heart Failure Comparison Between Patients With and Without Coronary Artery Disease

Hypercholesterolemia is a risk factor for development of coronary artery disease (CAD), however, several reports have suggested that low serum cholesterol is associated with a worse prognosis in patients with congestive heart failure (CHF). The objective of this study was to determine the prognostic value of cholesterol for CHF. The study subjects consisted of 133 consecutive patients hospitalized in our institution for progressive heart failure from April 2000 to March 2003. Thirty-two percent of the patients had CAD. After improvement of congestive heart failure and discharge from the hospital, lipid profiles, including serum total cholesterol (TC), triglycerides, and high and low density lipoprotein cholesterol (HDL, LDL, respectively), were obtained. During the follow-up period (2.3 +/- 0.9 years), 21 patients died. There was a significant difference between survivors and nonsurvivors in HDL (53 +/- 15, 43 +/- 15 mg/dL, P = 0.01), but no differences were observed in other variables. In patients with CAD, survivors had significantly lower TC concentrations (179 +/- 30 versus 246 +/- 55 mg/dL, P = 0.004), although in patients without CAD, survivors had significantly higher TC concentrations (203 +/- 37 versus 170 +/- 40 mg/dL, P = 0.02). Multivariate analysis showed high TC predicted a worse outcome in patients with CAD (odds ratio (OR) = 1.052, 95% confidence interval (CI) 1.002-1.104, P = 0.04), but a better outcome in patients without CAD (OR = 0.972, 95% CI 0.948-0.997, P = 0.03), independent of age, gender, medication, and complications. Thus, low serum cholesterol is associated with an improved outcome in patients with CAD, while it predicts a worse outcome in patients without CAD.

Impaired left ventricular diastolic function during isometric exercise in asymptomatic patients with hyperlipidaemia

BACKGROUND

Left ventricular (LV) diastolic dysfunction is an early sign, and may be more sensitive indicator, of ischaemic heart disease (IHD) than systolic dysfunction.

METHODS

LV diastolic function was assessed during isometric exercise (IME) in 37 consecutive normotensive hyperlipidaemics (LIP), without cardiac history or symptoms. Each patient underwent a stress ECG test and 2-D echo and Doppler cardiography. During the latter, transmitral flow at rest and at peak standardised IME using handgrip was studied. From the tracings, the E/A (peak velocity of the early/atrial components), the contribution of atrial systole to LV filling (ACF), the deceleration time (DT) of the E wave and the isovolumic relaxation time (IVRT) were calculated. Results were compared to 37 age-matched normal healthy volunteers (NOR).

RESULTS

Resting E/A was not different between NOR and the LIP. A significant reduction in E/A with IME was observed in LIP but not in NOR. Impaired LV filling (shown by E/A<1) was demonstrated in five patients (13%) at rest and in 20 patients (54%) at peak IME. All NOR had E/A>1 suggesting normal LV filling. Fifteen of the 30 patients with negative stress ECG test demonstrated LV diastolic dysfunction. ACF was higher in LIP than NOR and increased significantly (P<0.005) by 23% during IME. DT and IVRT in LIP were not different from NOR. In neither NOR nor LIP, were the LV diastolic functional parameters related to gender, smoking habit or levels of total cholesterol, LDL- or HDL-cholesterol or triglycerides.

CONCLUSION

The prevalence of LV diastolic dysfunction in asymptomatic patients with hyperlipidaemia despite a negative stress ECG test may be evidence of early underlying pre-clinical myocardial ischaemia.

Apolipoprotein A-IMilanoand 1-Palmitoyl-2-oleoyl Phosphatidylcholine Complex (ETC-216) Protects the in Vivo Rabbit Heart from Regional Ischemia-Reperfusion Injury

Ex vivo studies demonstrated that a synthetic high-density lipoprotein (HDL) comprised of a complex of recombinant apolipoprotein A-IMilano and 1-palmitoyl-2-oleoyl phosphatidylcholine protects the isolated rabbit heart from reperfusion injury. Therefore, we sought to determine whether a pharmaceutical preparation of this complex, ETC-216, was cardioprotective in an in vivo model of left anterior descending artery (LAD) occlusion and reperfusion. Initially, ETC-216 (100 mg/kg) was tested in acute (one-treatment) and chronic (two-treatment) i.v. administrations. ETC-216-treated rabbits developed smaller infarcts expressed as percentage of area at risk (p <0.01) compared with vehicle treatments. No differences were noted between chronic and acute administration. Therefore, ETC-216 (10, 3, or 1 mg/kg) or equivalent vehicle volumes were acutely infused. Compared with vehicle, ETC-216 reduced infarct size as a percentage of the area at risk at 10 (p <0.0005) and 3 mg/kg (p <0.05). No significant differences occurred at 1 mg/kg. To determine whether ETC-216 could protect the heart after initiation of ischemia, the synthetic HDL (10 mg/kg) was infused intravenously beginning 5 min before the end of 30 min of LAD occlusion. Infarct size as percentage of the area at risk was 31.6 +/- 3.0 (ETC-216) versus 49.5 +/- 2.5 (vehicle) (p <0.001), and as percentage of left ventricle was 19.7 +/- 1.6 (ETC-216) versus 34.1 +/- 2.3 (vehicle) (p <0.0005). Electron microscopy demonstrated that ETC-216 prevented irreversible cardiac damage as assessed by mitochondrial granulation and sarcomere contraction band formation. These findings suggest ETC-216 reduces reperfusion injury and may have utility for coronary artery revascularization procedures.

Cardiac Systolic and Diastolic Dysfunction After a Cholesterol-Rich Diet

Background— Although hypercholesterolemia is a well-established risk factor for coronary artery disease, little is known regarding its direct effects on cardiac function.

Methods and Results— We examined the effects of cholesterol feeding (0.5%) on cardiac function in rabbits. After 10 weeks, both systolic shortening and diastolic relaxation rates were impaired without any change in aortic pressure or ventricular hypertrophy. However, sarcoplasmic/endoplasmic reticulum Ca2+-ATPase (SERCA)-2 mRNA levels were reduced within 4 days after initiation of cholesterol feeding. After this effect, SERCA-2 protein and SERCA-mediated Ca uptake into sarcoplasmic reticulum vesicles were impaired, and the ratio of MHC-β to MHC-α mRNA increased 5-fold. Suppression of the SERCA-2 message correlated temporally with enrichment of the cardiac sarcolemma with cholesterol.

Conclusions— These data demonstrate that dietary hypercholesterolemia induces a “cholesterol cardiomyopathy” characterized by systolic and diastolic dysfunction. These alterations were independent of vascular disease and demonstrate a dietary link to cardiac dysfunction.

The pre-existence of an acute coronary event predicts differences in biological parameters and clinical evolution among patients with longstanding stable angina

BACKGROUND

To date, patients displaying stable angina with or without a previous acute coronary event have been grouped together and are offered nowadays, similar clinical approach. However, from clinical experience, increasing doubt exists whether they behave clinically in the same way. In the current study, we investigated whether differences might exist in the clinical, angiographic and biological parameters between these two distinct clinical presentations.

METHODS

The cardiovascular risk factor profile, clinical evolution, angiographic data, white blood cell (WBC) count and plasma concentrations of lipids and fibrinogen were compared between two groups of patients with longstanding stable angina. The first group consisted of 160 subjects who had undergone myocardial infarction (MI) as the first manifestation of coronary artery disease (CAD) and had no further coronary event. The second group was composed of 226 subjects who had effort-induced angina but never experienced an acute coronary event. The mean period between the first CAD manifestation and entry into the study was 7+/-6 years for MI group and 7+/-4 years for patients with uneventful angina.

RESULTS

MI patients displayed 8% higher WBC count (P=0.038), 20% higher fibrinogen (P=0.001), 12% lower HDL cholesterol (P=0.02), 8% lower apoA1 (P=0.005) and 46% higher lipoprotein (a) (P=0.005) than patients who presented an uneventful clinical course. Upon multivariate logistic regression analysis, fibrinogen (OR=1.14; 95% CI=1.08-1.28; P=0.033), lipoprotein (a) (OR=1.19; 95% CI=1.05-1.34; P=0.0036) and HDL cholesterol levels (OR=0.97; 95% CI=0.94-0.99; P=0.0095) remained independently associated with the pre-existence of MI. Patients with prior MI evolved more frequently towards clinically refractory angina (P=0.04). In addition, fibrinogen levels were independently associated with evolution to clinically refractory angina (OR=1.03; 95% CI=1.005-1.550; P=0.0448).

CONCLUSIONS

Stable CAD patients with a prior MI differ from those who display an uneventful effort-induced angina in their biological profile and their evolution towards clinically refractory angina.

High-density lipoproteins protect isolated rat hearts from ischemia-reperfusion injury by reducing cardiac tumor necrosis factor-alpha content and enhancing prostaglandin release

The incidence and severity of primary cardiac events are inversely related to the plasma concentration of high-density lipoproteins (HDLs). We investigated whether HDLs may exert a direct cardioprotection in buffer-perfused isolated rat hearts, which underwent a 20-minute low-flow ischemia followed by a 30-minute reperfusion. The administration of HDLs at physiological concentrations (0.5 and 1.0 mg/mL) during the 10 minutes immediately before ischemia rapidly and remarkably improved postischemic functional recovery and decreased creatine kinase release in the coronary effluent. Reconstituted HDLs containing apolipoprotein A-I (apoA-I) and phosphatidylcholine, but not lipid-free apoA-I or phosphatidylcholine liposomes, were also effective in protecting the heart from ischemia-reperfusion injury. HDLs at reperfusion were less effective than when given before ischemia. HDLs caused a dose-dependent reduction of ischemia-induced cardiac tumor necrosis factor-alpha (TNF-alpha) expression and content, which correlated with the improved functional recovery. A parallel increase of TNF-alpha release in the coronary effluent was observed, due to a direct binding of cardiac TNF-alpha to HDLs. Taken together, these findings argue for a cause-effect relationship between the HDL-mediated removal of TNF-alpha from the ischemic myocardium and the HDL-induced cardioprotection. Indeed, etanercept, a recombinant TNF-alpha-blocking protein, caused a dose-dependent improvement of postischemic functional recovery. HDLs also enhanced ischemia-induced prostaglandin release, which may contribute to the cardioprotective effect. A low plasma HDL level may expose the heart to excessive ischemia-reperfusion damage, and HDL-targeted therapies may be helpful to induce immediate or delayed myocardial protection from ischemia-reperfusion injury.

Effects of menopause on intraindividual changes in serum lipids, blood pressure, and body weight--the Chin-Shan Community Cardiovascular Cohort study

In Taiwan, the Chin-Shan Community Cardiovascular Cohort (CCCC) was assessed prospectively to determine whether the changes in cardiovascular risk factors for women age 45--54 years are due to menopause. The average paired percentage changes that occurred between baseline (1990-1991) and follow-up (4 years later) in fasting serum lipids were compared in three groups of women including groups of 59 and 224 who were pre- and postmenopausal, respectively, and a group of 118 who had spontaneously stopped menstruating. Postmenopausal women had the least gain in body mass index (BMI), whereas, mainly premenopausal women had increased systolic blood pressure (P<0.05). All women had elevated total cholesterol (TC) levels, with the greatest elevation in women transitioning into menopause (P<0.001). Low-density lipoprotein cholesterol (LDL-C) levels increased before and during the transition to menopause, but decreased after menopause (P<0.01). Age had significant association with changes in TC, triglyceride (TG) and LDL-C levels, whereas BMI had significant association with changes in TG, LDL-C, and high-density lipoprotein cholesterol (HDL-C) levels (P<0.05). After controlling for age and BMI, only differences in TC remained significant, with the greatest gain in women who stopped menstruating (12.9%) followed by pre- (6.5%) and postmenopausal women (4.8%). Changes in both systolic and diastolic blood pressures, and TG and HDL-C levels were not significantly different, but HDL-C levels declined between 11.5 and 14.7% in all groups. This study suggests an unfavorable effect of menopause on lipid metabolism, especially on the TC level, which was predominantly elevated during the transition to menopause. The decline of HDL-C is of concern.

Efficacy of cholesterol levels and ratios in predicting future coronary heart disease in a Chinese population

In this study, we assessed the efficacy of various lipid and lipoprotein measurements at baseline for predicting the risk for coronary heart disease (CHD) and determined the associated risk of CHD in subgroups stratified by different lipid and lipoprotein screening strategies to evaluate the adequacy of current total and low-density lipoprotein (LDL) cholesterol-based approaches in lipid management. We analyzed data from the Chin-Shan Community Cardiovascular Cohort study, a Chinese population-based prospective cohort study that began in 1990. During an 8-year follow-up period, 213 of 3,159 participants (6.7%) without CHD (aged > or =35 years) developed CHD. The total cholesterol/high-density lipoprotein (HDL) cholesterol ratio was the most powerful lipoprotein predictor of future CHD (hazard ratio 1.21 for a 1.0 increment in ratio; p <0.001). Subjects with "high-risk" LDL cholesterol levels (>160 mg/dl) and low total cholesterol/HDL cholesterol ratios (< or =5) had an incidence of CHD similar to those with low levels of both LDL cholesterol (< or =130 mg/dl) and total cholesterol/HDL cholesterol ratios (4.9% vs 4.6%). In contrast, subjects with "low-risk" LDL cholesterol levels (< or =130 mg/dl) and high total cholesterol/HDL cholesterol ratios (>5) had a 2.5-fold higher incidence of CHD than those with similar LDL cholesterol levels but low total cholesterol/HDL cholesterol ratios (p <0.001). Compared with using an LDL cholesterol level of 130 mg/dl as the cut-off point, using a total cholesterol/HDL cholesterol ratio of 5 was associated with superior specificity (73% vs 59%, p <0.001) and accuracy (72% vs 58%, p <0.001), and similar sensitivity (50% vs 53%). Our data indicate that current guidelines for lipid management may misclassify subjects with high levels of HDL and LDL cholesterol as well as those with low levels of HDL and LDL cholesterol. Using the ratio of total to HDL cholesterol as the initial screening tool can obviate this discrepancy.

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

Left ventricular (LV) mass is a powerful predictor for future cardiovascular events. Epidemiologic studies have shown that hyperlipidemia is associated with higher LV mass. The effects of statin therapy for hyperlipidemia on LV mass have not been studied. To determine the effects of statin therapy on LV mass, we prospectively studied 3 groups of age and body surface area-matched patients: group 1 (n = 20), patients with systemic hypertension and hyperlipidemia treated with pravastatin plus anti-hypertensive drugs; group 2 (n = 20), patients with hypertension and hyperlipidemia treated with hypertensive agents and diet control alone; and group 3 (n = 20), hypertensive patients with normolipidemia treated with antihypertensive agents. A group of controls without hypertension or hyperlipidemia was used for comparison. Echocardiograms were recorded at baseline and after 6-month therapy. All hypertensive groups showed significant decreases in LV mass index after treatment. Group 1 had the greatest decrease in LV mass and it was significantly higher than in groups 2 and 3. Multivariate analysis revealed that regression of LV mass was significantly correlated only with the use of statins and sex (p = 0.005 and 0.01, respectively, R(2) = 0.47). Linear regression analysis in group 1 showed a significant correlation between changes in arterial compliance and LV mass regression (r = 0.57, p = 0.01). Thus, the addition of a statin may have an additional effect on reducing LV mass, independent of lipid-lowering effects.