Reconstituted HDL in acute coronary syndromes.

OBJECTIVES: The strong inverse relationship between plasma high-density lipoprotein (HDL)-cholesterol and atherosclerotic cardiovascular disease provides the epidemiological basis that HDL is atheroprotective. Since HDL enhances cholesterol efflux and exhibits potent antiinflammatory properties, the aim of the present study was to investigate whether infusion of reconstituted HDL (rHDL) impacts on vascular function, a well-established surrogate of atherosclerotic vascular disease, as well as markers of inflammation and oxidative stress in patients with acute coronary syndromes (ACS). METHODS: Twenty-nine patients with ACS were randomized to double-blind treatment with rHDL or albumin. Endothelium-dependent and independent vasodilatation to intraarterial acetylcholine and sodium nitroprusside were measured by forearm venous occlusion plethysmography. In addition, oxidized LDL and high-sensitivity C-reactive protein were determined as markers of oxidative stress and vascular inflammation. RESULTS: rHDL infusion increased plasma HDL (P < 0.0001) and decreased LDL (P < 0.0001). Oxidized LDL (P= 0.11), high-sensitivity C-reactive protein (P= 0.12) and the response to endothelium-dependent and -independent vasodilatators remained unchanged after rHDL compared to albumin infusion (14.9 ± 9.2 versus 14.5 ± 12.4, P= 0.93 and 12.8 ± 7.1 versus 13.2 ± 9.6, P= 0.27, respectively). CONCLUSIONS: An increase of HDL and a reduction of LDL notwithstanding, human rHDL did not improve vascular function in patients with ACS thus further challenging the clinical benefit of interventions, which rapidly raise HDL in ACS, particularly with the infusion of reconstituted HDL.

Spontanous periodic breathing is associated with sympathetic hyperreactivity and baroreceptor dysfunction in hypertension.

OBJECTIVES: Intermittent periods of hypoxemia such as during periodic breathing are associated with hypertension and increased sympathetic activity. In patients with sleep apnea syndrome, hypertension is common. Treating apnea improves hypertension and reduces sympathetic outflow. The aim of the present study was to investigate the phenomenon and mechanisms of spontaneous periodic breathing in patients with hypertension. METHOD: We examined 43 hypertensive patients with untreated hypertension without left-ventricular dysfunction, heart failure or sleep apnea syndrome. Muscle sympathetic nerve activity (MSA), heart rate (HR), blood pressure (BP) and respiration were continuously recorded at rest and during cold-pressor testing. Oxygen and a CO2-enriched gas were used to test central and peripheral chemoreceptors, respectively. Baroreceptor gain was measured using the alpha method. RESULTS: Seven out of 43 patients showed spontaneous periodic breathing while awake. No difference in MSA, HR and BP was seen between patients with and without periodic breathing at rest except the breathing pattern. However, the cold-pressor test caused a larger increase of MSA in patients with periodic breathing (203 +/- 62 vs. 62 +/- 8%, P < 0.0001 by ANOVA), as well as systolic (46 +/- 6 vs. 25 +/- 3 mmHg, P = 0.002) and diastolic BP (26 +/- 5 vs. 12 +/- 1 mmHg, P = 0.004, ANOVA). Baroreceptor gain was markedly higher in patients with periodic breathing. Chemoreceptor sensitivity was comparable. CONCLUSION: Spontaneous periodic breathing is relatively common in patients with hypertension and is associated with greatly enhanced responses to cold-pressor testing. We suggest increased baroreceptor gain and sympathetic outflow as a cause for the oscillatory respiration pattern via barorespiratory coupling.

Cholesterylestertransfer protein inhibition and endothelial function in type II hyperlipidemia.

INTRODUCTION: While elevated plasma HDL levels are inversely correlated with cardiovascular events, raising HDL with the CETP inhibitor torcetrapib, however, was associated with increased cardiovascular morbidity and mortality in the ILLUMINATE trial. Whether the deleterious clinical effects of torcetrapib represent a molecule specific off-target effect, a class effect of CETP inhibitors or both is matter of ongoing debate. As such, the aim of the present study was to investigate whether CETP-inhibition with JTT-705, a molecule distinctly different from torcetrapib, impacts on vascular function, a well-established surrogate of atherosclerotic vascular disease, as well as markers of inflammation and oxidative stress in patients with type II hyperlipidemia. METHODS AND RESULTS: Eighteen patients were randomized to receive JTT-705 600 mg/d or matching placebo for 4 weeks. Flow-mediated dilation (FMD) was measured using ultrasonography of the brachial artery. HDL-C increased by 26% from 1.14 mmol/l to 1.44 mmol/l (p=0.01) in the JTT-705 group, while triglycerides decreased from 2.52 mmol/l to 1.97 mmol/l (p=0.03). CETP- inhibition with JTT-705, however, did not change FMD (3.1+/-0.6% to 3.6+/-0.4%; p=0.48). Interestingly, in a sub group analysis of patients with lower than median HDL-C (<1.19 mmol/l), FMD increased by 41% in patients vs. patients with higher than median HDL-C (>1.19 mmol/l; p=0.01). Markers of vascular inflammation (CRP, ICAM-1, IL-6, TNF alpha), as well as plasma endothelin-1 levels all remained unchanged throughout the study. CONCLUSION: In patients with type II hyperlipidemia, CETP inhibition with JTT-705 increased HDL-C and lowered triglycerides but improved endothelial function in the subgroup of patients with low baseline HDL-C levels only.

Dark chocolate improves coronary vasomotion and reduces platelet reactivity.

BACKGROUND: Dark chocolate has potent antioxidant properties. Coronary atherosclerosis is promoted by impaired endothelial function and increased platelet activation. Traditional risk factors, high oxidative stress, and reduced antioxidant defenses play a crucial role in the pathogenesis of atherosclerosis, particularly in transplanted hearts. Thus, flavonoid-rich dark chocolate holds the potential to have a beneficial impact on graft atherosclerosis. METHODS AND RESULTS: We assessed the effect of flavonoid-rich dark chocolate compared with cocoa-free control chocolate on coronary vascular and platelet function in 22 heart transplant recipients in a double-blind, randomized study. Coronary vasomotion was assessed with quantitative coronary angiography and cold pressor testing before and 2 hours after ingestion of 40 g of dark (70% cocoa) chocolate or control chocolate, respectively. Two hours after ingestion of flavonoid-rich dark chocolate, coronary artery diameter was increased significantly (from 2.36+/-0.51 to 2.51+/-0.59 mm, P<0.01), whereas it remained unchanged after control chocolate. Endothelium-dependent coronary vasomotion improved significantly after dark chocolate (4.5+/-11.4% versus -4.3+/-11.7% in the placebo group, P=0.01). Platelet adhesion decreased from 4.9+/-1.1% to 3.8+/-0.8% (P=0.04) in the dark chocolate group but remained unchanged in the control group. CONCLUSIONS: Dark chocolate induces coronary vasodilation, improves coronary vascular function, and decreases platelet adhesion 2 hours after consumption. These immediate beneficial effects were paralleled by a significant reduction of serum oxidative stress and were positively correlated with changes in serum epicatechin concentration.

Asymmetrical dimethylarginine (ADMA) and coronary endothelial function in patients with coronary artery disease and mild hypercholesterolemia.

OBJECTIVE: To investigate the association of the endogenous nitric oxide synthase inhibitor asymmetrical dimethylarginine (ADMA) and coronary endothelial function. METHODS AND RESULTS: In 289 patients with coronary artery disease we assessed coronary endothelium-dependent and -independent vascular responses to intracoronary infusion of acetylcholine, adenosine, and nitroglycerin, respectively, and determined plasma ADMA and l-arginine concentrations by HPLC. After 6 months of treatment with either cerivastatin, nifedipine, cerivastatin+nifedipine, or placebo, coronary vascular function testing as well as ADMA and l-arginine determinations were repeated. We observed no correlation of plasma ADMA or l-arginine concentration and coronary response to acetylcholine, adenosine or nitroglycerin baseline, and no correlation of changes of ADMA or l-arginine plasma concentration with changes in coronary function (all r and rho<0.3, all p>0.05). CONCLUSION: At physiological plasma concentrations ADMA appears to have only little impact on coronary endothelial function.

Chronic treatment with long-acting nifedipine reduces vasoconstriction to endothelin-1 in essential hypertension.

Essential hypertension is associated with enhanced biological activity of endothelin-1 (ET-1) and impaired endothelium-dependent vasodilatation. Dihydropyridine calcium antagonists have antioxidant activity in vitro, and they improve endothelial function in vivo. We tested whether calcium antagonists also influence the biological activity of ET-1 in essential hypertensive (EH) patients in the presence and absence of hypercholesterolemia. In 9 healthy subjects (normotensive [NT] subjects, age: 48.3+/-7.6 years; blood pressure: 118+/-8.6/69+/-5.4 mm Hg) and 21 EH subjects (age: 50.0+/-7.8 years; blood pressure: 164.4+/-5.4/103.8+/-4.4 mm Hg), we studied forearm blood flow and its modification induced by intrabrachial administration of ET-1, phenylephrine, acetylcholine, and sodium nitroprusside at baseline and after 24 weeks of treatment with a nifedipine gastrointestinal therapeutic system (30 to 60 mg per day). At baseline, the first dose of ET-1 (0.5 microg/100 mL of forearm tissue per minute) caused a slight vasodilatation in NT but not in EH subjects, whereas the following higher doses caused a comparable dose-dependent vasoconstriction in EH and NT subjects. The effect of acetylcholine was significantly reduced in EH as compared with NT subjects. In contrast, sodium nitroprusside and phenylephrine had similar effects in NT and EH subjects. After chronic treatment with the nifedipine gastrointestinal therapeutic system, the vasoconstrictor effect induced by both ET-1 and phenylephrine was significantly blunted, whereas the response to acetylcholine was significantly increased and the vasodilation to sodium nitroprusside unchanged. Hypercholesterolemic EH subjects showed a further reduced response to acetylcholine compared with normocholesterolemic EH subjects, and the nifedipine gastrointestinal therapeutic system restored the vasodilation to acetylcholine in this subgroup. In conclusion, in EH subjects, chronic treatment with a long-acting dihydropyridine calcium antagonist not only exhibits a blood pressure-lowering effect but also reduces ET-1-induced vasoconstriction and improves endothelium-dependent vasodilation. Those vasculoprotective effects may importantly contribute to a reduction in major clinical events seen during treatment with these compounds.

Protection of endothelial function: targets for nutritional and pharmacological interventions.

The vascular endothelium synthesizes and releases a spectrum of vasoactive substances and therefore plays a fundamental role in the basal and dynamic regulation of the circulation. Nitric oxide (NO)-originally described as endothelium-derived relaxing factor-is released from endothelial cells in response to shear stress produced by blood flow, and in response to activation of a variety of receptors. After diffusion from endothelial to vascular smooth muscle cells, NO increases intracellular cyclic guanosine-monophosphate concentrations by activation of the enzyme guanylate cyclase leading to relaxation of the smooth muscle cells. NO has also antithrombogenic, antiproliferative, leukocyte-adhesion inhibiting effects, and influences myocardial contractility. Endothelium-derived NO-mediated vascular relaxation is impaired in spontaneously hypertensive animals. NO decomposition by free oxygen radicals is a major mechanism of impaired NO bioavailability. The resulting imbalance of endothelium-derived relaxing and contracting substances disturbs the normal function of the vascular endothelium. Endothelin acts as the natural counterpart to endothelium-derived NO. Besides its arterial blood pressure rising effect in humans, endothelin-1 induces vascular and myocardial hypertrophy, which are independent risk factors for cardiovascular morbidity and mortality. Current therapeutic strategies concentrate mainly on lowering low-density lipoprotein cholesterol and an impressive reduction in the risk for cardiovascular morbidity and mortality has been achieved. Inflammatory mechanisms play an important role in vascular disease and inflammatory plasma markers correlate with prognosis. The production of reactive oxygen species under pathological conditions may represent an important inflammatory trigger. Novel therapeutic strategies specifically targeting inflammation thus bear great potential for the prevention and treatment of atherosclerotic vascular disease. In this context, the vascular actions of flavanol-rich cocoa, particularly with regard to enhanced NO synthesis and endothelial function observed in humans following consumption, warrants further attention. This review discusses pharmacological and dietary intervention.

Cardiovascular disease in HIV infection.

The survival of patients with HIV infection who have access to highly active antiretroviral therapy has dramatically increased. In HIV-infected persons, cardiovascular disease can be associated with HIV infection, opportunistic infections or neoplasias, use of antiretroviral drugs or treatment of opportunistic complications, mode of HIV acquisition (such as intravenous drug use), or with the classic non-HIV-related cardiovascular risk factors (such as smoking or age). Diseases of the heart associated with HIV infection or its opportunistic complications include pericarditis and myocarditis. Pericarditis may lead to pericardial effusion rarely causing tamponade. Cardiomyopathy is often clinically silent with asymptomatic left ventricular systolic dysfunction. Endocarditis is mainly the consequence of intravenous drug abuse, possibly leading to life-threatening valvular insufficiency with the need for cardiac surgery. A further serious condition associated with HIV infection is pulmonary hypertension potentially leading to right heart failure. The cardiovascular complications of HIV infection such as cardiomyopathy and pericarditis have been reduced by highly active antiretroviral therapy, but premature coronary atherosclerosis is now a growing problem because antiretroviral drugs can lead to serious metabolic disturbances resembling those in the metabolic syndrome. Lipodystrophy, a clinical syndrome of peripheral fat wasting, central adiposity, dyslipidemia, and insulin resistance, is most prevalent among patients treated with protease inhibitors. These patients should thus be screened for hyperlipidemia, hyperglycemia, and hypertension, and they may be candidates for lipid-lowering therapies. When initiating lipid-lowering therapy, interactions between statins and HIV protease inhibitors affecting cytochrome P450 function must be considered. Restenosis rate after percutaneous coronary intervention may be unexpectedly high.

Coffee blunts mental stress-induced blood pressure increase in habitual but not in nonhabitual coffee drinkers.

Coffee is widely consumed, especially during mental stress conditions. Cardiovascular impact of coffee remains debated because the underlying mechanisms of action are complex. We reported previously differential cardiovascular stimulation of coffee at rest depending on habitual consumption. The present study was designed to evaluate the effects of coffee on cardiovascular response to mental stress. In 15 healthy volunteers (6 habitual, 9 nonhabitual coffee drinkers), we assessed the effect of mental stress on blood pressure (BP), heart rate (HR), and muscle sympathetic activity (MSA) before and after a triple espresso, intravenous caffeine, and placebo in the same subjects. Under baseline conditions, mental stress significantly increases MSA (+2.5+/-0.7 volts per minute; +14.1+/-10.3%), systolic (+11.6+/-4.1 mm Hg) and diastolic BP (+6.4+/-2.0 mm Hg), and HR (+9.6+/-1.8 minutes(-1)). In nonhabitual coffee drinkers, a triple espresso but not caffeine induced an additional increase in systolic BP (+9+/-6.3 mm Hg; P=0.003) during mental stress, whereas in habitual drinkers, the stress-induced BP increase was blunted (+4+/-3.9 mm Hg; P=NS). As a result, nonhabitual coffee drinkers experienced significantly higher BP during mental stress than habitual drinkers (151+/-17.9/83+/-5.6 mm Hg versus 130+/-7.8/74+/-6.7 mm Hg; P<0.05). Caffeine induced similar effects in habitual and nonhabitual coffee drinkers at rest and during mental stress. The response to the cold pressor test was not influenced by coffee drinking in both groups. In conclusion, in nonhabitual coffee drinkers, coffee enhances the cardiovascular response to mental stress with an additional increase in systolic BP, whereas in habitual drinkers, the response is blunted. Caffeine alone does not exert any potentiating effect, confirming that ingredients other than caffeine are partially responsible for the stimulating effect of coffee on the cardiovascular system.

Rapid progression of atherosclerotic coronary artery disease in patients with human immunodeficiency virus infection.

We describe the case of a 39-year-old human immunodeficiency virus (HIV)-infected man with angiographically documented rapid progression of coronary artery disease. Over a time course of only 2 months, he developed high-grade stenosis of the left anterior descending coronary artery. The risk of myocardial infarction is increased in patients with HIV infection receiving antiretroviral therapy. However, the absolute risk is small and the marked overall benefits of antiretroviral therapy are evident. Patients receiving HIV protease inhibitors should be screened for hyperlipidemia, hyperglycemia, and hypertension. They may be candidates for lipid-lowering therapies depending on their long-term prognosis and individual risk of cardiovascular disease. Care is need because of possible drug interactions between lipid-lowering drugs and antiretroviral therapy. Invasive treatment of acute myocardial infarction does not differ from that in patients not infected with HIV. The rate of progression of coronary artery disease and the restenosis rate, however, are often unexpectedly high in these patients.

Cardiac arrest in a soccer player: a unique case of anomalous coronary origin detected by 16-row multislice computed tomography coronary angiography.

Anomalous origin of the coronary arteries may be present in otherwise normal subjects without clinical significance, but can also be the cause of myocardial ischemia and sudden death in both adults and teenagers. In particular, the origin of the left main coronary artery or left anterior descending artery from the right sinus of Valsalva or right coronary artery may result in compression of the vessel during or immediately after exercise. We present a unique case of coronary anomaly with four separate coronary ostia originating from the right coronary sinus in a soccer player with sudden cardiac arrest. Multislice contrast-enhanced computed tomography has emerged as a valid noninvasive method for the diagnosis of coronary artery anomaly.

Cardiovascular effects of coffee: is it a risk factor?

Intake of coffee, one of the most common beverages worldwide, is often reported as a cardiovascular risk factor; however, definitive data are lacking. Acute intake of coffee or beverages containing caffeine can increase blood pressure, heart minute volumes, and cardiac index, as well as activate the sympathetic nervous system in nonhabitual coffee drinkers. Interestingly, this is not observed in habitual coffee drinkers. Restriction of coffee or caffeinated beverages is no longer indicated in the seventh report of the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure (JNC 7) guidelines for the treatment of hypertension. In fact, no clear association between coffee and the risk of hypertension, myocardial infarction, or other cardiovascular diseases has been demonstrated. In contrast to early studies, recent research indicates that habitual moderate coffee intake does not represent a health hazard and may even be associated with beneficial effects on cardiovascular health.

Endogenous estrogens increase postischemic hyperemia in the skin microcirculation.

Estrogens have been recognized as a major regulator of vascular tone and structure, particularly in the skin. The objective of this study was to investigate the effects of endogenous estrogens on the skin microcirculation. Skin blood flow was measured at the forearm at rest and during postischemic hyperemia using laser Doppler flowmetry in 32 healthy women (mean age 34.5 +/- 3.9 years) involved in an in-vitro fertilization program. Women were treated for 10 to 12 days with gonadotropin-releasing hormone agonist (total dose 40.3 +/- 3.3 mg) and human menopausal gonadotropin (1942 +/- 801 IE) or follicle-stimulating hormone (2544 +/- 1071 IE) according to individual estrogen levels. Plasma estrogen levels increased from 132 +/- 90 pmol/L (36 +/- 25 pg/mL) to 8471 +/- 4386 pmol/L (2308 +/- 1195 pg/mL) during treatment (P < 0.0001). Maximal hyperemic blood flow increased from 353 +/- 81% before treatment to 516 +/- 144% after hormonal stimulation (P < 0.0001), whereas basal skin flow was not altered. This study shows that endogenous estrogens enhance the postischemic hyperemic response of the skin microcirculation.

Endothelial function and dysfunction. Part II: Association with cardiovascular risk factors and diseases. A statement by the Working Group on Endothelins and Endothelial Factors of the European Society of Hypertension.

Dysfunction of the vascular endothelium is a hallmark of most conditions that are associated with atherosclerosis and is therefore held to be an early feature in atherogenesis. However, the mechanisms by which endothelial dysfunction occurs in smoking, dyslipidaemia, hyperhomocysteinaemia, diabetes mellitus, arterial hypertension, cerebrovascular diseases, coronary artery disease and heart failure are complex and heterogeneous. Recent data indicate that endothelial dysfunction is often associated with erectile dysfunction, which can precede and predict cardiovascular disease in men. This paper will provide a concise overview of the mechanisms causing endothelial dysfunction in the different cardiovascular risk factors and disease conditions, and of the impact of the intervention measures and treatments.

Shear stress-dependent platelet function after LDL cholesterol apheresis.

BACKGROUND: Platelets play a crucial role in the pathogenesis of acute coronary syndrome (ACS). Thrombus formation with subsequent arterial occlusion is a major determinant in ACS and stroke. Platelets also essentially contribute to the development and progression of atherosclerotic lesions. The aim of the present study was to investigate the effects lipid lowering by LDL apheresis on platelet function in patients with coronary artery disease. METHODS: In six patients with angiographically proven coronary artery disease, venous blood samples were obtained before and after LDL cholesterol apheresis. Citrated whole blood (200 microl) was circulated in polystyrene wells at a shear rate of 1875 s(-1) for 2 min with a rotating teflon cone. Shear-stress dependent platelet adhesion was measured before and after apheresis. RESULTS: After apheresis, there were significant reductions in LDL (-58%) and HDL (-17%) cholesterol, triglycerides (-43%), fibrinogen (-52%), lipoprotein (a) (-57%) and CRP (-57%) levels. LDL apheresis significantly reduced shear-stress dependent platelet adhesion. Bolus administration of heparin significantly prolonged activated clotting time, but had no significant effect on platelet adhesion or aggregates. CONCLUSIONS: In patients with coronary artery disease, shear-stress dependent platelet adhesion is reduced by a single LDL apheresis. In addition to its cholesterol-lowering effect, LDL apheresis reduces circulating levels of fibrinogen and C-reactive protein.

Lyme carditis: restitutio ad integrum documented by cardiac magnetic resonance imaging.

Lyme disease is a tickborne illness that could cause, weeks to months later, complications involving the joints, central nervous system, and cardiovascular system. We report a case of cardiac manifestation with transitory higher degree atrioventricular block and dysfunction of the left ventricle. Complete resolution without signs of myocardial scar is demonstrated by cardiac magnetic resonance imaging.

Double aortic and pulmonary valves: An artifact generated by ultrasound refraction.

Echocardiography is an essential diagnostic tool for the investigation of the cardiovascular system. However, the nature of the ultrasound beam may lead to artifacts such as doubling of cardiac structures because of refraction. Here we present two illustrative cases showing doubling of the aortic ring and double regurgitation through the pulmonary valve. Doubling by refraction is different from other artifacts generating double images, such as mirroring of the ultrasound beam (eg, by prosthetic valves). Anatomic structures between the transducer and the heart such as the pleura, pericardium, or rib cartilage may induce refraction of the ultrasound beam resulting in doubling of cardiac structures. The resulting doubling of anatomic structures must not be misdiagnosed.