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A Thesis submitted to The University of Arizona College of Medicine - Phoenix in partial fulfillment of the requirements for the Degree of Doctor of Medicine. / To analyze the roles of CCTA, MPI, and CC to formulate a sequential clinical algorithm to use in patients with chest pain, risk factors for CAD, and an abnormal EKG. The goals of the study are to streamline and refine workup, to decrease radiation exposure to patients, and to contain costs. 39 patients underwent CCTA, MPI, and CC within 30 months of each other. CCTA was used to categorize mild, moderate, or severe CAD. MPI used SSS, SDS, TID, and formal reading to define mild, moderate, or severe physiologic ischemia. CC and coronary intervention cine films were analyzed to define and treat anatomical CAD medically or by intervention. Results: There was strong correlation between CCTA, CC, and treatment type (p<0.0001). CCTA was able to stratify all patients with mild or severe ischemia to appropriate treatment groups, and to reduce the need for MPI. With moderate ischemia from CCTA, the additional use of MPI could have reduced the need for 16/18 (89%) patients who underwent CC to undergo further testing. No patients with mild or moderate CAD by CCTA, followed by mild to moderate physiologic ischemia by MPI, needed CC or intervention. 37/39 patients (95%) could have avoided one or more tests using our algorithm. CCTA followed by MPI may be used in symptomatic patients with risk factors for CAD and an abnormal EKG to stratify mild and moderate CAD, and to thereby avoid cardiac catheterization. Our algorithm could lead to savings in healthcare expenditures, save patients from unnecessary invasive procedures, decrease radiation exposure, and total cost.

Un C-arm est un appareil d’imagerie médicale par rayons X utilisé en radiologie interventionnelle. La plupart des C-arms modernes sont capables de tourner autour du patient tout en acquérant des images radiographiques, à partir desquelles une reconstruction 3D peut être effectuée. Cette technique est appelée angiographie rotationnelle et est déjà utilisée dans certains centres hospitaliers pour l’imagerie des organes statiques. Cependant son extension à l’imagerie du cœur ou du thorax en respiration libre demeure un défi pour la recherche. Cette thèse a pour objet l’angiographie rotationnelle pour l’analyse du myocarde chez l’homme. Plusieurs méthodes nouvelles y sont proposées et comparées à l’état de l’art, sur des données synthétiques et des données réelles. La première de ces méthodes, la déconvolution par FDK itérative synchronisée à l’ECG, consiste à effacer les artéfacts de stries dans une reconstruction FDK synchronisée à l’ECG par déconvolution. Elle permet d’obtenir de meilleurs résultats que les méthodes existantes basées sur la déconvolution, mais reste insuffisante pour l’angiographie rotationnelle cardiaque chez l’homme. Deux méthodes de reconstruction 3D basées sur l’échantillonnage compressé sont proposées : la reconstruction 3D régularisée par variation totale, et la reconstruction 3D régularisée par ondelettes. Elles sont comparées à la méthode qui constitue l’état de l’art actuel, appelé « Prior Image Constrained Compressed Sensing » (PICCS). Elles permettent d’obtenir des résultats similaires à ceux de PICCS. Enfin, deux méthodes de reconstruction 3D+temps sont présentées. Leurs formulations mathématiques sont légèrement différentes l’une de l’autre, mais elles s’appuient sur les mêmes principes : utiliser un masque pour restreindre le mouvement à la région contenant le cœur et l’aorte, et imposer une solution régulière dans l’espace et dans le temps. L’une de ces méthodes génère des résultats meilleurs, c’est-à-dire à la fois plus nets et plus cohérents dans le temps, que ceux de PICCS / A C-arm is an X-ray imaging device used for minimally invasive interventional radiology procedures. Most modern C-arm systems are capable of rotating around the patient while acquiring radiographic images, from which a 3D reconstruction can be performed. This technique is called C-arm computed tomography (C-arm CT) and is used in clinical routine to image static organs. However, its extension to imaging of the beating heart or the free-breathing thorax is still a challenging research problem. This thesis is focused on human cardiac C-arm CT. It proposes several new reconstruction methods and compares them to the current state or the art, both on a digital phantom and on real data acquired on several patients. The first method, ECG-gated Iterative FDK deconvolution, consists in filtering out the streak artifacts from an ECG-gated FDK reconstruction in an iterative deconvolution scheme. It performs better than existing deconvolution-based methods, but it is still insufficient for human cardiac C-arm CT. Two 3D reconstruction methods based on compressed sensing are proposed: total variation-regularized 3D reconstruction and wavelets-regularized 3D reconstruction. They are compared to the current state-of-the-art method, called prior image constrained compressed sensing (PICCS). They exhibit results that are similar to those of PICCS. Finally, two 3D+time reconstruction methods are presented. They have slightly different mathematical formulations but are based on the same principles: using a motion mask to restrict the movement to the area containing the heart and the aorta, and enforcing smoothness of the solution in both space and time. One of these methods outperforms PICCS by producing results that are sharper and more consistent throughout the cardiac cycle

La pratique clinique a été profondément transformée par l'explosion technologique, ces dernières décades, des techniques d'imagerie médicale. L'expansion de la radiologie interventionnelle a ainsi rendu possible des procédures dites « minimalement invasives » au cours desquelles la thérapie est délivrée directement au niveau de la région pathologique via des micro-outils guidés par imagerie à travers le système vasculaire. Des systèmes dits « C-arm », générant une imagerie rayons X planaire temps-réelle en faible dose, sont utilisés pour le guidage. Ils ont offert plus récemment la possibilité d'une visualisation tridimensionnelle par le biais d'acquisitions tomographiques. C'est dans ce contexte de reconstruction tomographique que s'inscrivent ces travaux de thèse. Ils s'attèlent en particulier à corriger les artefacts de mouvement dus aux variations temporelles des vaisseaux injectés et se concentrent sur un aspect central de la tomographie, à savoir l'échantillonnage angulaire. La théorie du compressed sensing identifie les conditions sous lesquelles des données sous-échantillonnées peuvent être reconstruites en minimisant une fonctionnelle qui combine un terme de fidélité quadratique et une contrainte parcimonieuse. S'appuyant sur cette théorie, un formalisme original de reconstruction est proposé : il repose sur la rétroprojection filtrée itérative, les algorithmes proximaux, la minimisation de normes L1 et l'homotopie. Ce formalisme est ensuite dérivé pour intégrer différentes contraintes spatiales et temporelles. Une telle stratégie s'avère plus performante que la rétroprojection filtrée analytique utilisée dans la pratique clinique, permettant la réduction d'artefacts de mouvement et d'échantillonnage dans des cas cliniques bien identifiés de l'imagerie cérébrale et abdominale. Les résultats obtenus soulignent l'une des principales contributions de ce travail, à savoir : l'importance de l'homotopie, en supplément de la régularisation, pour améliorer la qualité image, un gain indispensable dans le domaine d'applicabilité / Medical imaging has known great advances over the past decades to become a powerful tool for the clinical practice. It has led to the tremendous growth of interventional radiology, in which medical devices are inserted and manipulated under image guidance through the vascular system to the pathology location and then used to deliver the therapy. In these minimally-invasive procedures, X-ray guidance is carried out with C-arm systems through two-dimensional real-time projective low-dose images. More recently, three-dimensional visualization via tomographic acquisition has also become available. This work tackles tomographic reconstruction in the aforementioned context. More specifically, it deals with the correction of motion artifacts that originate from the temporal variations of the contrast-enhanced vessels and thus tackles a central aspect of tomography: data (angular) sampling. The compressed sensing theory identifies conditions under which subsampled data can be recovered through the minimization of a least-square data fidelity term combined with sparse constraints. Relying on this theory, an original reconstruction framework is proposed based on iterative filtered backprojection, proximal splitting, `1-minimization and homotopy. This framework is derived for integrating several spatial and temporal penalties. Such a strategy is shown to outperform the analytical filtered backprojection algorithm that is used in the current clinical practice by reducing motion and sampling artifacts in well-identified clinical cases, with focus on cerebral and abdominal imaging. The obtained results emphasize one of the key contributions of this work that is the importance of homotopy in addition to regularization, to provide much needed image quality improvement in the suggested domain of applicability.

Objetivo: Determinar a sensibilidade e a especificidade da pesquisa do nistagmo de privação vertebrobasilar (PNPVB), Angiorressonância magnética (AngioRM), investigação ultrassonográfica cervical e Doppler transcraniano (DTC) em pacientes com diagnóstico clínico de insuficiência vertebrobasilar (IVB). Método: o estudo foi aprovado pela comissão de ética local. Os participantes deram consentimento formal. Foi formado grupo de estudo (GE) e grupo controle (GC) com 12 sujeitos em cada, pareados por sexo e idade, sendo 4 masculinos e 8 femininos, com média de idade de 72,66 (±8.35 anos). Os doentes foram selecionados do Ambulatório de Otoneurologia do HC-FMUSP com idade acima de 55 anos, sem outra provável causa de tonturas. Voluntários assintomáticos do Grupo de Apoio Multidisciplinar ao Idoso Ambulatorial (GAMIA) formaram o GC. Todos os participantes realizaram avaliação cardiogeriátrica para excluir qualquer doença de base que pudesse ser a causa da tontura, que não a IVB. Assim, os dois grupos realizaram a PNPVB, a AngioRM, a avaliação ultrassonográfica cervical e DTC. Resultados: PNPVB, AngioRM e avaliação ultrassonográfica cervical não mostraram diferenças entre os grupos. No DTC, foram detectadas diferenças significantes em cinco variáveis: velocidade do pico sistólico da artéria cerebral média direita (ponto de corte em 76,00; sensibilidade de 0,83; especificidade de 0,75; p=0,012), velocidade diastólica final da artéria basilar (ponto de corte em 24,00; sensibilidade de 0,66; especificidade de 0,66; p=0,028), índice de pulsatilidade (IP) da artéria cerebral média esquerda (ponto de corte em 0,85; sensibilidade de 0,83; especificidade de 0,75; p=0,005), IP da artéria cerebral média direita (ponto de corte em 0,88; sensibilidade de 0,75; especificidade de 0,75; p=0,010), IP da artéria basilar (ponto de corte em 1,01; sensibilidade de 0,91; especificidade de 0,91; p < 0,001). Considerando-se o IP da artéria basilar, calculou-se o poder estatístico para uma amostra com 12 sujeitos em cada grupo, sendo > 95%. Conclusão: a PNPVB e a AngioRM não mostraram diferenças entre os grupos. O DTC mostrou sensibilidade de 91% e especificidade de 91% para o diagnóstico da IVB relacionada à tontura, quando o IP da artéria basilar for maior que 1,01 / Objective: To determine the sensitivity and specificity of the vertebro-basilar deprivation nystagmus (VBDN), magnetic resonance angiography (MRA), cervical ultrasonographic investigation and Transcranial Doppler Ultrasound (TDU) in patients with clinical diagnosis of vertebro-basilar insufficiency (VBI). Methods: The study was approved by the Ethics in Research Committee. The patients gave formal consent for participating in this study. We composed 2 groups: a study group (SG) and a control group (CG), comprised of 12 patients each, with sex- and age-matched patients (4 men and 8 women). Their mean age was 72.66 (±8.35) years. The study group included patients from the neurotology outpatient clinic of the HC-FMUSP who were over 55 years old, without any other possible cause for dizziness than VBI. Asymptomatic volunteers from the geriatrics outpatient clinic were included in the CG. All participants were subjected to evaluation of a cardio-geriatric professional, to exclude any subjacent disease that could cause dizziness other than VBI. Then, both groups were subjected to VBDN, MRA, cervical ultrasonographic investigation and TDU. Results: The VBDN, MRA and cervical ultrasonographic investigation did not demonstrate differences between the groups. The TDU demonstrated that the systolic pulse velocity of the right middle cerebral artery (sensitivity=0.83, specificity=0.75; p=0.028), final diastolic velocity of the basilar artery (sensitivity=0.66; specificity=0.66; p=0.028), pulsatility index (PI) of the left middle cerebral artery (sensitivity=0.83; specificity=0.75; p=0,005), PI of the right middle cerebral artery (sensitivity=0.75; specificity=0.75; p=0.010), and the PI of the basilar artery (sensitivity=0.91; specificity=0.91; p < 0.001) were significantly higher in the diseased group compared to controls. Considering the PI of the basilar artery, we observed that the statistic power of the test was higher than 95%. Conclusion: The VBDN, MRA and cervical ultrasonographic investigation did not demonstrate significant changes in patients with VBI compared to controls. The PI of the basilar artery, measured using the TDU, demonstrated high sensitivity (91%) and specificity (91%) levels in the diagnosis of VBI when the PI was higher than 1.01

Os vasos de fino calibre apresentam maior risco para reestenose e revascularização da lesão alvo. Limitações relacionadas com a navegabilidade dos sistemas de dilatação por balão e menor capacidade de acomodação da neoíntima podem contribuir para isto. O stent autoexpansível de nitinol Sparrow® dedicado a vaso de calibre < 2,75 mm, resultou num conjunto com perfil de um fio-guia 0,014\". Testado na forma de stent de metal puro no estudo CARE I, revelou-se seguro e eficaz em vasos de fino calibre. Este estudo avaliou, de forma pioneira, o despenho de um stent autoexpansível farmacológico neste cenário. O objetivo primário foi comparar a perda luminal tardia no vaso-alvo pela angiografia coronária quantitativa ao final de oito meses, entre os stents Sparrow® farmacológico e não farmacológico, em coronárias com diâmetro de referência < 2,75 mm. Casuística e métodos: Os pacientes foram randomizados de forma prospectiva em dois grupos para procedimento de angioplastia: um grupo com o emprego o stent Sparrow® farmacológico (sirolimus), e ou outro grupo com o stent Sparrow® na versão não farmacológica. Análise pela angiografia coronária quantitativa foi realizada imediatamente antes e após o procedimento e aos oito meses, com seguimento clínico de 24 meses. Foi utilizado o programa IBM SPSS Statistics® para análise estatística e foi considerado nível de significância de 5% e poder de 80% para o cálculo do tamanho da amostra. Resultados: 24 pacientes foram randomizados, 12 no grupo com stent farmacológico Sparrow® e 12 no grupo com a versão não farmacológica. Na avaliação angiográfica aos oito meses verificou-se significativa redução de perda luminal tardia no grupo com o stent farmacológico Sparrow® em comparação com grupo com a versão não farmacológica (0,25 + 0,16 mm versus 0,97 + 0,76 mm, p = 0,008, IC 95% de -1,19 ; -0,22). No seguimento clínico de 12 meses, não foram observados eventos cardíacos adversos maiores (morte, infarto ou necessidade de revascularização do vaso alvo) no grupo com stent farmacológico. Não ocorreu trombose intrastent. Conclusão: Em pacientes submetidos à angioplastia transluminal percutânea em artérias coronárias com diâmetro de referência < 2,75 mm, o emprego do stent farmacológico autoexpansível Sparrow®, em comparação com a versão não farmacológica do mesmo stent, resultou em significativa redução de perda luminal tardia, sem ocorrência de eventos clínicos que deponham contra a segurança do dispositivo pesquisado. / Small vessels represent a group with high risk for restenosis and target lesion revascularization. Limitations associated with navigability of balloon dilation systems and less accommodating of the neointima may contribute to this. The self-expanding Sparrow® stent system dedicated to the vessel size <2.75 mm resulted in a profile similar to a 0.014\" guide wire angioplasty. Tested as bare metal stent in the CARE trial I, the Sparrow® stent system has proved to be safe and effective in small vessels. This study evaluated, for the first time, the performance of a self-expanding drug eluting stent in this scenario. The primary objective was to compare the in-stent late lumen loss by quantitative coronary angiography at the end of eight months between the Sparrow® drug-elutig stent and Sparrow® bare metal stent in coronary arteries with reference diameter <=2.75 mm. Materials and methods: Patients were prospectively randomized (1:1) Analysis by quantitative coronary angiography was performed immediately before and after the procedure and at eight months with clinical follow-up to 12 months. We used the IBM® SPSS for statistical analysis and was considered a significance level of 5% and 80% power for the calculation of sample size. Results: 24 patients were randomized, 12 in each group. At Eight months follow-up there was significant reduction in late lumen loss in the Sparrow® drug-eluting stent group compared to the Sparrow® bare metal stent group (0.25 ± 0.16 mm vs. 0.97 + 0.76 mm, p = 0.008, 95% CI -1.19 to -0.22). Up to 12 months of clinical follow-up there no cases of death, myocardial infarction and target vessel revascularization Of note, there was no stent thrombosis. Conclusion: In patients undergoing percutaneous transluminal angioplasty in coronary arteries with reference diameter <= 2.75 mm, the use of Sparrow® drug-eluting stent, compared to the Sparrow® bare metal stent, resulted in significant less late loss without occurrence of clinical events that weigh against the security of device.

A Artéria de Adamkiewicz é a maior artéria radiculomedular anterior que alcança a artéria espinal anterior, sendo responsável pelo suprimento sanguíneo de até dois terços distais da medula espinal. Uma lesão desta artéria durante um procedimento cirúrgico implica em graves complicações como paresia de membros inferiores e também paraplegia, muitas vezes de caráter definitivo, podendo acontecer durante a realização do tratamento cirúrgico de aneurismas toracoabdominais e patologias da coluna vertebral. Geralmente a artéria de Adamkiewicz está localizada entre a oitava vértebra torácica e a primeira lombar. Os exames de angiotomografia computadorizada da medula espinal e angioressonância magnética são métodos seguros, não invasivos e amplamente utilizados para identificá-la. Esta investigação teve como objetivo avaliar a Artéria de Adamkiewicz através da Angiotomografia Computadorizada Coronariana de Múltiplos Detectores acoplado ao Eletrocardiograma. Por meio de estudo prospectivo, foram analisados 86 exames de angiotomografia coronariana. Os exames foram analisados por dois investigadores independentes e a confiabilidade inter e intraobservador das variáveis nível de origem e lado de entrada foi avaliada. Os resultados evidenciaram uma taxa de identificação da artéria de Adamkiewicz em 71 (82,5%) exames. O nível de origem foi identificado entre T9 e T11 em 56 (79,2%) exames. Em relação ao lado, em 65 (91,5%) pacientes o lado de entrada foi o lado esquerdo. O exame de angiotomografia computadorizada coronariana de Múltiplos Detectores acoplado ao Eletrocardiograma mostrou taxas de identificação da artéria de Adamkiewicz semelhantes aos encontrados nos exames de angiografia, angiotomografia computadorizada e angioressonância da medula espinal / The Adamkiewicz artery is the most important radiculomedular artery that reaches the anterior spinal artery and is responsible for blood supply to distal two thirds of the spinal cord. An injury to this artery during a surgical procedure involves serious complications such as paresis of lower limbs and also paraplegia, often permanently, which may happen during the surgical treatment of thoracoabdominal aneurysms and pathologies of the spine. Usually the Adamkiewicz artery is located between the eighth thoracic vertebra and the first lumbar. Computed tomography angiography scans and spinal magnetic resonance angiography are safe methods, non-invasive and widely used to identify it. This research aimed to evaluate the artery of Adamkiewicz by Computed Coronary Tomography Angiography with multiple detectors coupled to Electrocardiogram. In a prospective study, we analyzed 86 exams of Computed Coronary Tomography Angiography. The exams were analyzed by two independent researchers and the inter and intraobserver reliability of the variables source level and entrance side was evaluated. The results showed an identification rate of Adamkiewicz artery in 71 (82.5%) examinations. The level of origin was identified between T9 and T11 in 56 (79.2%) examinations. In relation to the side, in 65 (91.5%) patients had the entrance side on the left side. Adamkiewicz artery evaluation by Angiotomography Coronary Computed with Multiple detectors coupled to Electrocardiogram showed Adamkiewicz artery identification rates similar to those found in angiography examinations, computadorized tomography angiography and magnetic resonance angiography of the spinal cord

Purpose: To evaluate the diagnostic performance of Coronary Computed Tomography Angiography (CCTA) in predicting Myocardial Perfusion Scintigraphy (MPS) perfusion defects in low likelihood patients with End Stage Renal Disease (ESRD) awaiting transplant. Materials and Methods: In total, 131 consecutive patients with ESRD awaiting transplant were prospectively enrolled in this study (86 men; 54±9years). All patients underwent MPS as per standard of care and in addition non-enhanced CT for calcium scoring (CAC score) and Coronary Computed Tomography Angiography (CCTA). Results: The sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of CAC score in predicting MPS perfusion defects were 88%, 35%, 28% and 92%, respectively. The sensitivity, specificity, PPV and NPV of CCTA in predicting MPS perfusion defects at the patient level were 55%, 87%, 57% and 87%, respectively, and 48%, 92%, 41% and 94% at the vessel level. The diagnostic performance of CCTA in predicting MPS perfusion defects improved when patients with CAC score higher than 1000 (15/70, 21%) were excluded from the analysis. In patients with positive CAC score up to 1000 sensitivity, specificity, PPV and NPV at the patient level were 60%, 93%, 75% and 86% respectively. These were 53%, 91%, 36% and 95%, respectively, at the vessel level. Conclusion: Non-enhanced CT for CAC score and CCTA can be considered useful diagnostic tools in the ESRD population, particularly in identifying patients without coronary artery disease. This approach however had limitations in the presence of high CAC score.

INTRODUÇÃO: A cineangiocoronariografia é um procedimento médico invasivo que envolve sentimentos de medo e ansiedade. Estudos internacionais têm avaliado o efeito da música como técnica de intervenção para redução da ansiedade utilizando-a antes, durante e depois da cineangiocoronariografia. Contudo, os resultados de sua aplicação durante o procedimento não são consensuais. OBJETIVO: A proposta do presente estudo foi avaliar o efeito da música, aplicada durante a realização do procedimento, na ansiedade de pacientes submetidos à cineangiocoronariografia pela primeira vez. MÉTODOS: Os desfechos estudados foram o nível de ansiedade medido pelo Inventário de Ansiedade Beck, a frequência cardíaca e pressão arterial, ambas medidas pelo método intra-arterial. Participaram do estudo 300 pacientes randomizados entre o grupo controle (procedimento padrão) ou grupo música (cineangiocoronariografia realizada com a intervenção musical). Foi realizado o cegamento da pesquisadora durante toda a coleta e análise estatística dos dados. RESULTADOS: Os grupos eram semelhantes em relação às características de base, bem como dados sobre os hábitos musicais dos pacientes e dados da cineangiocoronariografia. Não foram observadas diferenças entre os grupos controle e música para todos os desfechos estudados: nível de ansiedade (p=0,072), pressão arterial sistólica (p=0,379), pressão arterial diastólica (p=0,152) e frequência cardíaca (p=0,853). Notou-se também que, mesmo antes da realização do procedimento, 80,9% do grupo controle e 76,9% do grupo música já apresentavam o menor nível de ansiedade (mínima). As mulheres mostraram-se mais ansiosas do que os homens (p=0,000 pré-exame e p=0,022 pós-exame). Não houve relação na comparação entre ansiedade e diferentes faixas etárias (p=0,352 pré-exame, p=0,198 pós-exame). CONCLUSÃO: A música aplicada no presente estudo durante a cineangiocoronariografia não se mostrou efetiva na redução dos níveis de ansiedade, pressão arterial e frequência cardíaca dos pacientes submetidos ao procedimento pela primeira vez. Constatou-se também que as mulheres são mais ansiosas do que os homens e que não houve relação entre o nível de ansiedade e faixas etárias / BACKGROUND: Coronary angiography is an invasive medical procedure that involves feelings of fear and anxiety. International studies have evaluated the effects of music intervention to reduce anxiety by using it before, during and after coronary angiography. However, the results of this strategy are not clear. OBJECTIVE: The aim of this study was to evaluate the effect of music, employed during the procedure, on anxiety of patients undergoing coronary angiography for the first time. METHODS: Outcomes were anxiety level measured by the Beck Anxiety Inventory, heart rate and blood pressure, both measured by intra-arterial method. The study included 300 patients randomized between the control group (standard procedure) or music group (standard procedure with a music intervention). The researcher was blinded throughout the data collection and statistical analysis. RESULTS: Baseline variables were adequatly balanced between both groups, as well as data on musical habits and coronary angiography. No differences were observed between the control group and music group in any of the outcomes: level of anxiety (p = 0.072), systolic blood pressure (p = 0.379), diastolic blood pressure (p = 0.152) and heart rate (p = 0.853). It was also noted that even before the procedure, 80.9% of the control group and 76.9% of the music group had low level of anxiety. Women were more anxious than men (p = 0.000 pre-test and p = 0.022 post-test). No relationship was found between anxiety and age (p = 0.352 pre-test, p = 0.198 post-test). CONCLUSION: The music used in this study during coronary angiography was not effective in reducing anxiety levels, blood pressure or heart rate in patients undergoing the procedure for the first time. It was also found that women are more anxious than men and that there was no relationship between anxiety levels and age

Cardiovascular disease remains a leading a cause of mortality and morbidity. Primary prevention is known to reduce the incidence of cardiovascular disease. The use of medication is currently targeted at those at increased predicted risk of cardiovascular disease using risk prediction tools developed from large epidemiological studies. However these have poor external validity particularly for those at low or intermediate risk: a significant number of cardiovascular events still occurs in these groups. We hypothesised that screening for asymptomatic pre-clinical cardiovascular disease using B-type natriuretic peptide (BNP) and whole body contrast enhanced magnetic resonance imaging (MRI) could identify those at low/intermediate risk or disease whowill develop clinical disease and thus facilitate improved targeting of primary prevention at those most likely to benefit. The Tayside Screening for Cardiac Events (TASCFORCE) study is a prospective normal volunteer cohort study. Men and women aged 40 years or older free from cardiovascular disease and with a predicted 10-year coronary heart disease risk less than 20% were recruited. All had comprehensive baseline cardiovascular risk information and a BNP level measured. If the BNP level was greater than the median for their gender participants were invited to attend for a whole body contrast enhancedMRI scan comprising cardiac imaging and whole body angiography. The images were analysed to measure left ventricular mass (LVM), left ventricular volumes and left ventricular function. These were indexed for body size using height, height1.7, height2.7 and body surface area. Angiogram images were analysed for the presence and degree of intraluminal stenosis. All participants are being followed up using anonymised electronic data linkage for incident cardiovascular disease and death. 4423 participants (39.3% male) were recruited between November 2007 and February 2013. Median age was 51.2 years. The median 10-year coronary heart disease (CHD) 23 risk was 2% and 13.6% had a CHD risk of 10-19.9% (intermediate risk). The medianBNP results for men and women were 7.5 and 15.3 pg/ml respectively. Age, female sex and high density lipoprotein were independently associated with BNP level. Heart rate, total cholesterol and ex-smoking status were independently inversely associated with BNP level. 1528 (74.8% of those invited) underwent an MRI scan. Mean left ventricular mass was 129.2g and 87.0g for men and women respectively. LVM and left ventricular mass index (LVMI) were significantly higher in men than women. The vast majority (94.6%) of arterial segments analysed were normal and 50.6% of individuals had no evidence of luminal stenosis. From follow up data obtained 2 years after the end of recruitment 18,364 person years at risk were analysed. 17 cardiovascularevents and no deaths occurred in those not invited for an MRI scan based on their BNP result and 16 events and 1 death occurred in those invited for an MRI scan. There was no significant difference in event rates between those with above and below median BNP levels, between those with higher or lower LVM or LVMI or between those with and without the presence of stenosis on angiography. As expected we have not demonstrated the ability of LVM, LVMI or stenosis burden determined using magnetic resonance imaging to predict cardiovascular disease in a population at low or intermediate risk of CHD. We have also not demonstrated the ability of BNP to identify those at low orintermediate risk of CHD who will develop clinical CV disease. However it is the pre-planned longer-term follow up where difference might be expected. The low number of events at this early stage in follow up mean that it is difficult to draw firm conclusions. As follow up continues and further events accumulate we hope to determine if these measures will be shown to predict cardiovascular events in future analyses. We have characterised the normal values and distribution of a range of left ventricular structural and functional parameters derived using a steady state free precision sequence MRI in a population at low or intermediate risk of CHD which will provide a useful reference for normal values that are different to other imaging modalities including chocardiography and other protocols of MRI scanning.