Darío Echeverri

Plaque Neovascularization Is Increased in Ruptured Atherosclerotic Lesions of Human Aorta Implications for Plaque Vulnerability

Background—Growth of atherosclerotic plaques is accompanied by neovascularization from vasa vasorum microvessels extending through the tunica media into the base of the plaque and by lumen-derived microvessels through the fibrous cap. Microvessels are associated with plaque hemorrhage and may play a role in plaque rupture. Accordingly, we tested this hypothesis by investigating whether microvessels in the tunica media, the base of the plaque, and the fibrous cap are increased in ruptured atherosclerotic plaques in human aorta. Methods and Results—Microvessels, defined as CD34-positive tubuloluminal capillaries recognized in cross-sectional and longitudinal profiles, were quantified in 269 advanced human plaques by bicolor immunohistochemistry. Macrophages/T lymphocytes and smooth muscle cells were defined as CD68/CD3-positive and &agr;-actin–positive cells. Total microvessel density was increased in ruptured plaques when compared with nonruptured plaques (P=0.0001). Furthermore, microvessel density was increased in lesions with severe macrophage infiltration at the fibrous cap (P=0.0001) and at the shoulders of the plaque (P=0.0001). In addition, microvessel density was also increased in lesions with intraplaque hemorrhage (P=0.04) and in thin-cap fibroatheromas (P=0.038). Logistic regression analysis identified plaque base microvessel density (P=0.003) as an independent correlate to plaque rupture. Conclusions—Thus, neovascularization as manifested by the localized appearance of microvessels is increased in ruptured plaques in the human aorta. Furthermore, microvessel density is increased in lesions with inflammation, with intraplaque hemorrhage, and in thin-cap fibroatheromas. Microvessels at the base of the plaque are independently correlated with plaque rupture, suggesting a contributory role for neovascularization in the process of plaque rupture.

Caffeine's Vascular Mechanisms of Action

Caffeine is the most widely consumed stimulating substance in the world. It is found in coffee, tea, soft drinks, chocolate, and many medications. Caffeine is a xanthine with various effects and mechanisms of action in vascular tissue. In endothelial cells, it increases intracellular calcium stimulating the production of nitric oxide through the expression of the endothelial nitric oxide synthase enzyme. Nitric oxide is diffused to the vascular smooth muscle cell to produce vasodilation. In vascular smooth muscle cells its effect is predominantly a competitive inhibition of phosphodiesterase, producing an accumulation of cAMP and vasodilation. In addition, it blocks the adenosine receptors present in the vascular tissue to produce vasoconstriction. In this paper the main mechanisms of action of caffeine on the vascular tissue are described, in which it is shown that caffeine has some cardiovascular properties and effects which could be considered beneficial.

The vasodilatory effects of levosimendan on the human internal mammary artery

BACKGROUND: Levosimendan, an inotropic drug that enhances myocardial contractility through myofilment calcium sensitazion, induces peripheral vasodilation via opening ATP-dependent K+ channels. It is unknown whether this drug can be used for the treatment of perioperative vasospasm of arterial conduits used for coronary artery bypass grafting. METHODS: We investigated the effects of levosimendan on human internal mammary artery (IMA) specimens taken from patients undergoing coronary artery bypass surgery. The rings were carefully prepared and placed between two wire hooks in organ bath chambers and then constricted submaximally with norepinephrine and thromboxane A2 analog (U46619). Nitroglycerin, milrinone, and levosimendan were separately added in a cumulative fashion and concentration response curves for relaxation were constructed. In parallel experiments, the response to levosimendan was evaluated on rings with and without functional endothelium. Levosimendan prevention of norepinephrine-induced contraction was also estimated. RESULTS: Nitroglycerin, milrinone, and levosimendan completely reversed the contraction of the IMA segments induced by U46619 and norepinephrine. Levosimendan produced a potent, concentration-dependent preventive effect on the norepinephrine-induced contraction of IMA. The responses to levosimendan were similar in preparations with or without endothelium.

831-1 Ruptured diabetic atherosclerotic plaques have more inflammation and neovascularization than ruptured plaques from patients without diabetes

Va sc ul ar D is ea se , H yp er te ns io n, a nd P re ve nt io n (23%). Over the two study periods, a smaller proportion of patients on bosentan than on placebo required epoprostenol therapy (2.8% versus 4.3%), additional therapy for PAH (28.6% versus 38.5%), or hospitalization (4.2% versus 13.0% for PAH-related and 16.0% versus 23.2% for all causes of hospitalization). Conclusion: The benefit achieved in exercise capacity, dyspnea, and reduced need for additional therapy or hospitalization demonstrated in the initial 16-week BREATHE-1 study appears to be sustained when patients are followed for 28 weeks.

Statins and percutaneous coronary intervention: A complementary synergy

The inclusion of statins and stents in coronary disease management during the 1980s has marked a dramatic change in the natural history of the disease. Separately, each of these therapies have progressed rapidly and have achieved a prime position in the current armamentarium. The simultaneous use of statins in patients undergoing percutaneous coronary revascularization procedures with stent implantation has shown a significant beneficial synergistic effect by reducing ischemia and necrosis, and improving coronary blood flow in patients with stable coronary disease, as well as in acute coronary syndromes. The use of high dose statins in conjunction with coronary angioplasty with stent implantation has shown great efficacy and safety in patients with severe coronary disease.

Reanimación cerebrocardiopulmonar prolongada exitosa: Reporte de un caso

Se presenta el caso de un paciente a quien se le realizo coronariografia diagnostica la cual reporto enfermedad coronaria de tres vasos. Inmediatamente despues de finalizar el procedimiento presento paro cardiorrespiratorio, y se iniciaron maniobras de reanimacion basicas y avanzadas por dos horas. Durante la reanimacion se practico angioplastia e implante de stent en la arteria circunfleja. El paciente recupero la circulacion espontanea y fue trasladado a la unidad de cuidado coronario; en el segundo dia se llevo a revascularizacion quirurgica miocardica exitosa y fue dado de alta luego de dieciseis dias del evento inicial sin deficit neurologico evidente.

Fístula de arteria coronaria derecha a arteria pulmonar. Reporte de un caso

Una fistula arteriovenosa coronaria se define como la comunicacion entre una de las arterias coronarias y una vena o una cavidad cardiaca. La fistula se localiza en la arteria coronaria derecha (55%) o en la arteria coronaria izquierda (35% de los casos). Parece que las conexiones entre el sistema coronario y una cavidad cardiaca se deben a la persistencia de los sinusoides y espacios intertrabeculares embrionarios. La mayoria de estas fistulas drenan al ventriculo derecho, la auricula derecha o el seno coronario. En la angiografia coronaria se detectan ocasionalmente fistulas entre arterias coronarias y pulmonares. PALABRAS CLAVE: fistula, arteria coronaria derecha, arteria pulmonar, dolor toracico. An arteriovenous fistula is defined as the communication between one coronary artery with a vein or to a cardiac cavity. The fistula is localized in the right coronary artery (55% of cases) or in the left coronary artery (35% of cases). It seems that the connections between the coronary system and a cardiac cavity are due to the persistence of embryonic sinusoids and intratrabecular spaces. Most of these fistulae drain into the right ventricle, the right atrium or to the coronary sinus. Occasionally, fistulae between the coronary and pulmonary arteries are found during a coronary angiography.

From Endothelial Dysfunction to Arterial Stiffness in Diabetes Mellitus

Prevalence of diabetes mellitus has increased drastically over time, especially in more populous countries such as the United States, India, and China. Patients with diabetes have an increased risk of major cardiovascular events such as acute myocardial infarction, cerebrovascular disease, and peripheral vascular disease. Arterial stiffness is a process related to aging and vascular, metabolic, cellular and physiological deterioration. In recent years it has been described as an independent predictor of cardiovascular mortality and coronary artery disease. Additionally, it plays an important role in the measurement of chronic disease progression. Recent studies have suggested a strong relationship between diabetes mellitus and arterial stiffness since they share a similar pathophysiology involving endothelial dysfunction. The literature has shown that microvascular and macrovascular complications in diabetic patients could be screened and measured with arterial stiffness. Additionally, new evidence proposes that there is a relationship between blood glucose levels, microalbuminuria, and arterial stiffness. Moreover, arterial stiffness predicts cardiovascular risk and is independently associated with mortality in diabetic patients. Abnormal arterial stiffness values in diabetic patients should alert the clinician to the presence of vascular disease, which merits early study and treatment. We await more studies to determine if arterial stiffness could be considered a routine useful non-invasive tool in the evaluation of diabetic patients. There is enough evidence to conclude that arterial stiffness is related to the progression of diabetes mellitus.

The doctor of the plague

Over the years, pollution has gained greater importance due to its environmental aspect in large cities, the impact on global warming, and its leading role in several of the main causes of mortality, such as cardiovascular disease and cancer. Throughout the history of medicine, researchers have noted a direct relationship between air quality and health. It all began with the miasma theory, which stated that diseases such as cholera, the black plague and malaria (from Italian words meaning ̈bad aïr), stemmed from contact with poisonous vapors known as ̈miasmä (from the Greek word for ̈contamination̈), a product of the putrefaction of matter. This led to the appearance of ‘‘il dottore della peste’’ in Venice in the 17th century: doctors garbed in a bird shaped mask with two lower holes full of spices, roses, herbs, and vinegar; a hat, and a robe, which helped them avoid these diseases that apparently were derived from contaminated air (fig. 1). Winter of 1952 in London was an unforgettable season due to the increased local atmospheric contamination, together with a thermal inversion, which created the famous ‘‘great smoke’’: a dense air mass which prevented transit in the streets, triggered chaos in the city, and called into ques-

Efecto del ejercicio aeróbico en la rigidez vascular en una población sana

Introduction A healthy lifestyle is key for cardiovascular health. There is controversy about beneficial vascular effects of physical exercise.