ABSTRACT
OBJECTIVES: The objective of this study was to describe the intraplaque variability of coronary atherosclerosis in humans. BACKGROUND: Atherosclerosis is a heterogeneous process. The degree and patterns of intraplaque heterogeneity are not well described. This study uses 3D intravascular ultrasound (IVUS) to examine variability in individual atherosclerotic plaques in human coronary arteries. METHODS: IVUS images of 170 coronary plaques in 98 patients were evaluated. Each plaque was divided into proximal, middle, and distal sections. Quantitative and qualitative analyses were performed for each section using a dedicated 3D IVUS protocol. Intralesion heterogeneity was assessed between sections. RESULTS: Heterogeneity in composition was observed in most plaques (89%). The pattern of remodeling was heterogeneous in 23% of lesions. External elastic membrane (EEM) areas demonstrated an average percent deviation of 28.9% +/- 15.5%. Positive remodeling was associated with longer lesions (>> median length of 12.7 mm) (P = 0.031). Soft and calcific sections had a smaller mean EEM area (P = 0.034). Calcific lesions had a smaller mean lumen area (P = 0.027) and a greater percent plaque burden (PPB) (P = 0.001). Neither the location within the vessel or within the plaque was associated with plaque morphology. Greater qualitative heterogeneity was found in patients presenting with acute coronary syndrome (P < 0.001). CONCLUSIONS: Our results demonstrate a high degree of heterogeneity in composition and morphological features within individual atherosclerotic plaques in human coronary arteries. Intraplaque heterogeneity represents a challenge for imaging protocols correlating plaque features with cardiovascular events and for the development of future therapeutic options.
Subject(s)
Coronary Artery Disease/diagnostic imaging , Coronary Vessels/diagnostic imaging , Imaging, Three-Dimensional/methods , Ultrasonography, Interventional/methods , Female , Follow-Up Studies , Humans , Male , Middle Aged , Reproducibility of Results , Retrospective Studies , Severity of Illness IndexABSTRACT
Most hypertensive patients require more than one medication to effectively control elevated blood pressure (BP) values. This multicenter, randomized, double-blind study was aimed at testing the efficacy and safety of the combination of low-dose nifedipine GITS 20 mg/ losartan 50 mg compared with either monotherapy in patients with grade 1 to 3 hypertension over an eight-week period. Of 352 patients enrolled in the study, 300 were randomized. All the three treatments lowered elevated BP without clinically relevant changes in heart rate. All the three treatments lowered mean 24-hour diastolic BP: nifedipine GITS/losartan -10.6 mm Hg, losartan -5.4 mm Hg, nifedipine GITS 20 mg -8.0 mm Hg. There was a statistically significant difference of diastolic BP change between patients receiving losartan compared with those receiving combination treatment (P < 0.05). Diastolic BP trough-to-peak ratio and smoothness index were highest in the patient group receiving combination therapy (70%). Nifedipine GITS monotherapy had the highest systolic BP trough-to-peak ratio of all treatment arms (78%) and higher diastolic BP trough-to-peak ratio and smoothness index than losartan monotherapy. All treatments were safe. These data provide evidence that in hypertensive patients combination of nifedipine GITS 20 mg and losartan 50 mg improves control of systolic and diastolic BP compared with either monotherapy.
Subject(s)
Antihypertensive Agents/therapeutic use , Hypertension/drug therapy , Losartan/therapeutic use , Nifedipine/therapeutic use , Adult , Aged , Blood Pressure/drug effects , Double-Blind Method , Drug Therapy, Combination , Female , Heart Rate/drug effects , Humans , Male , Middle AgedABSTRACT
A VENG é uma técnica que tem sido empregada rotineiramente em nossos pacientes, nos últimos 15 anos. As duas principais contribuiçöes da VENG para o estudo da funçäo vestibular periférica säo: a apreciaçäo da compensaçäo labiríntica e a possibilidade de avaliaçäo clínica do nervo vestibular inferior. O estudo da compensaçäo vestibular mostrou que muito freqüentemente esse fenômeno näo ocorre para os canais verticais mesmo em casos com perfeita compensaçäo para os canais laterais. É óbvio que a VENG aumenta a sensibilidade dos testes vestibulares nesses casos, tornando fácil entender porque pacientes com resultados normais nos testes labirínticos usuais (limitados aos canais laterais) apresentam sintomas vestibulares. Uma vez que a prova rotatória pendular decrescente permite a estimulaçäo de cada canal semicircular posterior separadamente, o nistagmo oblíquo resultante dessa estimulaçäo constitui-se que no primeiro registro clínico da funçäo do nervo vestibular inferior e de suas vias no Sistema Nervoso Central. Nossa crescente experiência com este método, particularmente para a exploraçäo específica dos canais semicirculares posterior e superior de cada lado, sugere que possa constituir um importante teste vestibular na rotina clínica, em futuro próximo
Subject(s)
Humans , Nystagmus, Pathologic , Vertigo/etiologyABSTRACT
Os autores apresentam uma modificaçäo do método original da vecto-electronistagmografia com o objetivo de simplificar o cálculo da medida da velocidade angular da componente lenta do nistagmo à vestibulometria
