Search PubMed⌕ Search

Biomedical subjects

V Fuster

Publications and source records attributed to V Fuster.

At least 19 recordsLinked to original sources
PubMed2001

The human high-risk plaque and its detection by magnetic resonance imaging.

The study of atherosclerotic disease during its natural history and after therapeutic intervention will enhance our understanding of the progression and regression of this disease and will aid in selecting the appropriate treatments. Several invasive and noninvasive imaging techniques are available to assess vessels in atherosclerotic disease. Most of the standard techniques, however, identify luminal diameter or stenosis, wall thickness, or plaque volume. None of the standard techniques can characterize the composition of an atherosclerotic plaque and therefore are incapable of identifying the high-risk plaques. High-resolution, multicontrast, magnetic resonance imaging (MRI) can noninvasively image vulnerable plaques and characterize plaques in terms of their different components (ie, lipid, fibrous, calcium, or thrombus). Application of MRI opens up whole new areas for diagnosis, prevention, and treatment of atherosclerosis.

Aged↗
PubMed2001

Effects of lipid-lowering by simvastatin on human atherosclerotic lesions: a longitudinal study by high-resolution, noninvasive magnetic resonance imaging.

BACKGROUND: This study was designed to investigate the effects of lipid-lowering by simvastatin on human atherosclerotic lesions. METHODS AND RESULTS: Eighteen asymptomatic hypercholesterolemic patients with documented aortic and/or carotid atherosclerotic plaques were selected for the study. A total of 35 aortic and 25 carotid artery plaques were detected. Serial black-blood MRI of the aorta and carotid artery of the patients was performed at baseline and 6 and 12 months after lipid-lowering therapy with simvastatin. The effects of the treatment on atherosclerotic lesions were measured as changes in lumen area, vessel wall thickness, and vessel wall area, a surrogate of atherosclerotic burden. Simvastatin induced a significant (P<0.01) reduction in total and LDL cholesterol levels at 6 weeks that was maintained thereafter. At 6 months, no changes in lumen area, vessel wall thickness, or vessel wall area were observed. However, at 12 months, significant reductions in vessel wall thickness and vessel wall area, without changes in lumen area, were observed in both aortic and carotid arteries (P<0.001). CONCLUSIONS: This in vivo human study demonstrates that effective and maintained lipid-lowering therapy by simvastatin is associated with a significant regression of atherosclerotic lesions. Our observation suggests that statins induce vascular remodeling, as manifested by reduced atherosclerotic burden without changes in the lumen.

Aorta↗
PubMed2001

Testing platelet activation with a shear-dependent platelet function test versus aggregation-based tests: relevance for monitoring long-term glycoprotein IIb/IIIa inhibition.

BACKGROUND: Tests developed to monitor glycoprotein (GP) IIb/IIIa blockade do not properly reflect platelet function in vivo and need a baseline (pretreatment) value. Because GP IIb/IIIa is essential in platelet aggregation and thrombosis under shear conditions, a flow-dependent approach to monitor its inhibition can be used. METHODS AND RESULTS: We compared a test based on flow-dependent platelet deposition, the Cone and Platelet Analyzer (CPA), with in vitro platelet aggregometry and the Rapid Platelet Function Assay (RPFA) on platelet function after GP IIb/IIIa inhibition. In vitro, increasing concentrations of abciximab (0% to 100% receptor occupancy) were tested. Ex vivo, platelet function was monitored with the CPA and with aggregometry for up to 1 week after abciximab administration. The CPA was better correlated with the percentage of free GP IIb/IIIa receptors than was aggregometry or the RPFA. Only the RPFA, when expressed as a ratio over baseline (pretreatment), was comparable to the CPA. Ex vivo, the CPA, but not aggregometry, showed prolonged platelet inhibition with gradual recovery from GP IIb/IIIa receptor blockade in the first week after abciximab administration. CONCLUSIONS: Platelet function assessment by shear-induced deposition is a reliable test to monitor a wide range of GP IIb/IIIa inhibition. Its accuracy does not require a baseline reference. The effects of GP IIb/IIIa blockade on platelet function should be examined under high shear conditions.

Abciximab↗
PubMed2001

Atherosclerotic aortic component quantification by noninvasive magnetic resonance imaging: an in vivo study in rabbits.

OBJECTIVES: We sought to demonstrate the ability that noninvasive in vivo magnetic resonance imaging (MRI) has to quantify the different components within atherosclerotic plaque. BACKGROUND: Atherosclerotic plaque composition plays a critical role in both lesion stability and subsequent thrombogenicity. Noninvasive MRI is a promising tool for the characterization of plaque composition. METHOD: Thoracic and abdominal aortic atherosclerotic lesions were induced in rabbits (n = 5). Nine months later, MRI was performed in a 1.5T system. Fast spin-echo sequences (proton density-weighted and T2-weighted [T2W] images) were obtained (in-plane resolution: 350 x 350 microns, slice thickness: 3 mm). Magnetic resonance images were correlated with matched histopathological sections (n = 108). RESULTS: A significant correlation (p < 0.001) was observed for mean wall thickness and vessel wall area between MRI and histopathology (r = 0.87 and r = 0.85, respectively). The correlation was also present on subanalysis of the thoracic and upper part of the abdominal aorta, susceptible to respiratory motion artifacts. There was a significant correlation for plaque composition (p < 0.05) between MRI and histopathology for the analysis of lipidic (low signal on T2W, r = 0.81) and fibrous (high signal on T2W, r = 0.86) areas with Oil Red O staining. T2-weighted images showed greater contrast than proton density-weighted between these different components of the plaques as assessed by signal intensity ratio analysis with the mean difference in signal ratios of 0.47 (S.E. 0.012, adjusted for clustering of observations within lesions) being significantly different from 0 (t1 = 39.1, p = 0.016). CONCLUSIONS: In vivo noninvasive high resolution MRI accurately quantifies fibrotic and lipidic components of atherosclerosis in this model. This may permit the serial analysis of therapeutic strategies on atherosclerotic plaque stabilization.

Animals↗
PubMed2001

Treatment of congestive heart failure: guidelines for the primary care physician and the heart failure specialist.

During the past 10 years, the philosophy of heart failure treatment has evolved from symptom control to a combined prevention and symptom-management strategy. Recent clinical trials have proved that early detection can delay progression. Treatment of asymptomatic left ventricular dysfunction is as important as treatment of symptomatic disease. The purpose of this review is to simplify recent guidelines for pharmacological management of chronic systolic heart failure for the primary care physician and the heart failure specialist. Early recognition and prevention therapies, combined with lifestyle modification, are essential in the treatment of heart failure. Therapy with angiotensin-converting enzyme inhibitors, beta-blockers, and diuretics is now standard. Digoxin is added to improve clinical symptoms, especially in patients with atrial fibrillation. Aldosterone antagonists may be recommended in select patients with stable New York Heart Association class III or IV heart failure. If angiotensin-converting enzyme inhibitors are not tolerated, angiotensin receptor blockers, hydralazine hydrochloride, and isosorbide dinitrate are recommended. The data on antiarrhythmic and anticoagulation therapies are inconclusive.

Adrenergic beta-Antagonists↗
PubMed2001

Thrombus formation on atherosclerotic plaques: pathogenesis and clinical consequences.

PURPOSE: To describe the characteristics of thrombus formation on atherosclerotic plaques, the clinical expression of atherothrombosis in vascular disease, and some of the most recent therapeutic approaches in cardiovascular disease. DATA SOURCES: MEDLINE search for English-language articles on thrombosis and atherosclerosis published up to January 2000. Abstracts of recent international meetings on new aspects of thrombus formation and new therapeutic options were reviewed, and references from identified articles were selected and reviewed. STUDY SELECTION: Experimental, basic, clinical, and epidemiologic studies related to the pathophysiology of thrombosis on atherosclerotic lesions. Therapeutic approaches were obtained from experimental studies and large clinical investigations. DATA EXTRACTION: Arterial vessel wall substrate, rheologic conditions, and blood thrombogenicity influence the process of thrombus formation in arteries. Thrombus formation on disrupted atherosclerotic plaques or arterial erosions frequently causes acute coronary syndromes. Severe atherosclerosis of the aorta has been identified as an important morphologic indicator of an increased risk for thromboembolism. Current antithrombotic therapies available as long-term treatment for patients with cardiovascular disease are often not effective enough to prevent acute thrombotic events and deterioration of atherosclerosis. DATA SYNTHESIS: Improved understanding of the pathophysiology of thrombus formation on atherosclerotic plaques has led to the development of new therapeutic approaches. Glycoprotein IIb/IIIa, tissue factor, factor Xa, and thrombin inhibitors as well as combined antithrombotic therapy, such as aspirin plus a thienopyridine plus warfarin, are being evaluated as new possible options for the treatment of arterial thrombosis. CONCLUSIONS: Long-term treatment with potent antithrombotic drugs, such as tissue factor or factor Xa inhibitors, that effectively block thrombosis without causing bleeding complications could help reduce death from cardiovascular disease.

Arteriosclerosis↗
PubMed2001

Chronic endothelial dysfunction after oversized coronary balloon angioplasty in pigs: a 12-week follow-up of coronary vasoreactivity in vivo and in vitro.

Previous studies have reported the development of vasoconstriction immediately after invasive coronary interventions. Other studies in animals have demonstrated that using oversized balloon angioplasty, vasospasm can be suppressed, even in the presence of endothelial denudation due to important structural alteration in vascular smooth muscle. The regenerated endothelium also appears to be impaired chronically by selective attenuation of in vitro endothelial dependent relaxation related to pertussis toxin-sensitive G proteins. The purpose of this investigation was to verify in vivo and in vitro vasoreactivity to bradykinin (BK) and serotonin (5-hydroxytryptamine; 5-HT) (endothelial dependent agonists) as well as to nitroglycerin (NTG) (exogenous nitric oxide donor) at different times after oversized balloon angioplasty intervention ranging from 1 h to 12 weeks, in normal porcine coronary arteries. BK-induced vasodilatation in vivo was impaired acutely, but it was restored after 4 weeks. Serotonin caused vasoconstriction in vivo that was significantly augmented after 12 weeks. Conversely, endothelium-dependent vasodilatation in vitro to BK and 5-HT remained attenuated during the whole period of follow-up. Finally, relaxation elicited by NTG was reduced in the in vivo experiment until the first week after the procedure. Histological analysis showed severe arterial injury, and complete recovery of endothelial coverage after 4 weeks. In conclusion, this experiment supports evidence for the occurrence of the acute attenuation of vasoresponsiveness and chronic endothelial dysfunction following overstretching coronary balloon angioplasty. Abnormal remodeling associated with the severity of injury may contribute to chronic endothelial dysfunction. Differences found between in vivo and in vitro studies also suggest that multiple endogenous influences present in the former can attenuate the greater endothelial dysfunction demonstrated by endothelial assessment in vitro.

Angioplasty, Balloon↗
PubMed2001

Initiation of hormone replacement therapy after acute myocardial infarction is associated with more cardiac events during follow-up.

OBJECTIVES: This study explored the association between the initiation of hormone replacement therapy (HRT) and early cardiac events (<1 year) in women with a recent myocardial infarction (MI). BACKGROUND: Observational studies have linked postmenopausal hormone use with a reduced risk of death from heart disease. However, a recent randomized trial of HRT found no long-term benefit, primarily due to an increase in cardiac events in the first year. METHODS: The Coumadin Aspirin Reinfarction Study (CARS) database contains information on HRT use and menopausal status for women with a recent MI. We classified the 1,857 postmenopausal women in CARS as prior/current HRT users if they took HRT before enrollment, new users if they began HRT during the study period or never users. We assessed the incidence of cardiac events (death, MI, unstable angina [UA]) during follow-up. RESULTS: In our cohort, 28% (n = 524) used HRT at some point. Of these, 21% (n = 111) began HRT after their MI. New users had a higher incidence of death/MI/UA (41% vs. 28%, p = 0.001) during follow-up than never users, largely due to a higher incidence of UA (39% vs. 20%, p = 0.001). After adjustment, new users still had a significantly higher risk of death/MI/UA than never users during follow-up (relative risk [RR] = 1.44 [1.05-1.99]). Prior/current users had no excess risk of the composite end point after adjustment. Users of estrogen/progestin had a lower incidence of death/MI/UA during follow-up than users of estrogen only (RR = 0.56 [0.37-0.85]). CONCLUSIONS: Postmenopausal women who initiated HRT after a recent MI had an increased risk of cardiac events largely due to excess UA during follow-up.

Aged↗
PubMed2001

Effect of p27 deficiency and rapamycin on intimal hyperplasia: in vivo and in vitro studies using a p27 knockout mouse model.

SUMMARY: Rapamycin, an immunosuppressant and antiproliferative agent, reduces intimal hyperplasia after arterial injury in animal models and in a preliminary study in humans. Rapamycin treatment reportedly increases expression of p27, a cyclin-dependent kinase inhibitor. This mechanism was tested using a p27-deficient (p27 -/-) murine model. Aortic smooth muscle cells from wild-type (WT) and p27 -/- mice were isolated and cultured. Cell proliferation, assessed by cell count and (3)H-thymidine incorporation, was inhibited significantly by rapamycin in WT and p27 -/- cells at concentrations of 1 ng/ml, 10 ng/ml, and 100 ng/ml (p < 0.05, versus control). The in vivo effect on intimal hyperplasia was studied in p27 -/- and WT mice after femoral artery transluminal injury. Rapamycin treatment was started 2 days before injury and maintained for 2 weeks (1 mg/kg per 48 hours, ip). No significant differences in intima-to-media ratio were found between WT (1.1 +/- 0.1) and p27 -/- mice (1.0 +/- 0.1) 4 weeks after injury. Rapamycin significantly (p < 0.05) reduced intima-to-media ratios in both WT (0.7 +/- 0.1) and p27 -/- mice (0.5 +/- 0.1), compared with untreated mice. p27 deficiency did not alter the arterial wall proliferative response to injury. The inhibitory effect of rapamycin on intimal hyperplasia occurred via a p27-independent mechanism. The in vitro data showed that this effect was mediated through decreased proliferation and enhanced apoptosis.

Animals↗
PubMed2001

Inbreeding in Gredos mountain range (Spain): contribution of multiple consanguinity and intervalley variation.

The present paper examines consanguineous marriages occurring between 1874 and 1975 in three valleys (Tormes, Alberche, and Tiétar) in the Sierra de Gredos mountain range, Avila province, Spain. Information was obtained from parish registers of 42 localities, corresponding to a total of 41,696 weddings. Consanguineous marriages were defined as those up to the third degree of consanguinity (second cousins). From 1874 to 1975 the percentage of related mates was 4.45% and the inbreeding coefficient was 0.0011868 (for 1874 to 1917 corresponding figures up to the fourth degree were 16.44% and 0.00 19085, respectively). In order to ascertain the characteristics and evolution of mating patterns in Gredos, the contribution of each degree of kinship was analyzed as a whole and then for each valley separately. Regarding total consanguineous marriages in Gredos, there is a low frequency of uncle-niece matings (0.21%) and a first-second cousin mating ratio (C22/C33) of 0.23 (up to the third degree of consanguinity). Before 1918 multiple matings (i.e., those involving more than a single relationship) accounted for 19.16% of consanguineous marriages (up to the fourth degree). The observed frequencies of multiple consanguineous marriages was, on average, about twice that expected at random, and the proportion of such marriages to total inbreeding was 34.65%. The temporal change of the Gredos inbreeding pattern was characterized by a recent decrease; the highest inbreeding levels correspond to the period from 1915 to 1944. Finally, intervalley differences (maximum inbreeding coefficient in the Tormes, minimum in the Tiétar) are interpreted considering the geography, population size, and population mobility for each valley

Consanguinity↗
PubMed2001

Coronary artery disease: pathogenesis and acute coronary syndromes.

Atherosclerotic diseases and their thrombotic complications remain the leading causes of mortality and morbidity in Western society. In the United States, cardiovascular disease is responsible for one in every 2.4 (41.4%) deaths and is the leading single cause of mortality. Furthermore, the presence of atherosclerotic disease (defined as thickening of the arterial wall through the accumulation of lipids, macrophages, T-lymphocytes, smooth muscle cells, extracellular matrix, calcium and necrotic debris) is more prevalent, but by itself rarely fatal. The crucial, final common process for the conversion of a nonocclusive, often clinically silent atherosclerotic lesion to a potentially fatal condition is often plaque disruption. The mortality associated with atherosclerotic disease relates to the acute coronary syndromes, including acute myocardial infarction, unstable angina pectoris and sudden cardiac death. Substantial clinical, experimental and postmortem evidence demonstrates the central role that a superimposed acute thrombosis on a disrupted atherosclerotic plaque plays in the onset of acute coronary syndromes. Therefore, therapeutic approaches to date have focused on reducing such thrombotic complications of atherosclerotic plaques (i.e., antiplatelet, anticoagulant and thrombolytic therapies) to reduce the resulting morbidity and mortality. In this review, we will focus on the current theories of atherogenesis and how they impact on our understanding of acute coronary syndromes.

Chemokines↗