Rubén Leta

Idiopathic dilated cardiomyopathy exhibits defective vascularization and vessel formation

Ultrastructural findings of idiopathic dilated cardiomyopathy (IDCM) include myocyte atrophy and myofilament loss, yet little is known about the vascular abnormalities present in IDCM.

Ruling Out Coronary Artery Disease with Noninvasive Coronary Multidetector CT Angiography before Noncoronary Cardiovascular Surgery

PURPOSE To assess the usefulness of preoperative coronary computed tomographic (CT) angiography in the detection of coronary artery disease (CAD) in nonselected patients scheduled to undergo noncoronary cardiovascular surgery to avoid unnecessary invasive coronary angiography (ICA). MATERIALS AND METHODS The institutional review board approved the study protocol; informed consent was given. This prospective study involved 161 consecutive patients who underwent coronary calcium scoring and coronary CT angiography before undergoing noncoronary cardiovascular surgery. Seven patients were excluded because of contraindications to CT angiography. The major indication of noncoronary cardiovascular surgery was valvular heart disease (121 patients). Follow-up was performed at a median of 20 months to define ischemic events described as acute coronary syndrome or death secondary to acute coronary syndrome, arrhythmias, or cardiac failure. Multivariate analysis was performed to determine predictors of nondiagnostic coronary CT angiography. Kaplan-Meier analysis was performed to evaluate outcome at follow-up. RESULTS Twenty-one patients did not undergo surgery, which left 133 patients as the study group. Atrial fibrillation was present in 45 of 133 patients. The interquartile range of the Agatston coronary calcium score was 0-471. Coronary CT angiography was diagnostic in 108 of 133 patients. Of these, 93 of 108 had no significant CAD (≤ 50% stenosis), and noncoronary cardiovascular surgery was performed in them without preoperative ICA. No patients in this group had postoperative ischemic events at follow-up. Coronary CT angiography was nondiagnostic in 25 of 133 patients who were referred for preoperative ICA. Multivariate analysis showed Agatston score to be the only independent predictor of nondiagnostic coronary CT angiography (odds ratio = 1.002; 95% confidence interval: 1.001, 1.003; P = .001). The best Agatston score cutoff for diagnostic coronary CT angiography was 579. CONCLUSION In nonselected patients scheduled to undergo noncoronary cardiovascular surgery, preoperative coronary CT angiography was diagnostic in 81% of cases. Preoperative ICA could be safely avoided in patients without significant CAD by using coronary CT angiography. The Agatston score, but not the presence of atrial fibrillation, was an independent predictor of nondiagnostic coronary CT angiography. SUPPLEMENTAL MATERIAL http://radiology.rsna.org/lookup/suppl/doi:10.1148/radiol.10100384/-/DC1.

A statistical shape model of the heart and its application to model-based segmentation

In the present paper we describe the automatic construction of a statistical shape model of the whole heart built from a training set of 100 Multi-Slice Computed Tomography (MSCT) studies of pathologic and asymptomatic patients, including 15 (temporal) cardiac phases each. With these data sets we were able to build a compact and representative shape model of both inter-subject and temporal variability. A practical limitation in building statistical shape models, and in particular point distribution models (PDM), is the manual delineation of the training set. A key advantage of the proposed method is to overcome this limitation by not requiring them. Another one is the use of MSCT images, which thanks to their excellent anatomical depiction, have allowed for a realistic heart representation, including the four chambers and connected vasculature. The generalization ability of the shape model permits its deformation to unseen anatomies with an acceptable accuracy. Moreover, its compactness allows for having a reduced set of parameters to describe the modeled population. By varying these parameters, the statistical model can generate a set of valid examples. This is especially useful for the generation of synthetic populations of cardiac shapes, that may correspond e.g. to healthy or diseased cases. Finally, an illustrative example of the use of the constructed shape model for cardiac segmentation is provided.

Non-Invasive Coronary Angiography With 16 Multidetector-Row Spiral Computed Tomography: a Comparative Study With Invasive Coronary Angiography

INTRODUCTION AND OBJECTIVES Non-invasive coronary artery angiography by 16 multidetector-row spiral computed tomography is a novel diagnostic tool whose reliability is still unclear. The aim of our study was to compare this technique with invasive coronary angiography. PATIENTS AND METHOD A total of 31 selected patients were examined with both angiographic methods. Non-invasive studies were performed with a helical computer tomography system (Toshiba Aquilion 16-slices). A contrast agent was injected into a peripheral vein, and cross-sectional images were reconstructed with a slice thickness of 0.5 mm or 1.0 mm. Findings from both techniques were analyzed according to a predetermined segmented anatomical model of the coronary artery. The detection and relevance of coronary artery lesions were evaluated, and lesions with a reduction in diameter of more than 50% were considered significant. RESULTS Non-invasive coronary angiography yielded an appropriate assessment in 88.4% of the coronary artery segments. The reasons that prevented correct segment evaluation were extensive coronary calcifications, inappropriate breath-hold, motion artefacts and small vessel size. Sensitivity and specificity for the detection of significant coronary lesions with the non-invasive method were 75% and 91%, respectively. Sensitivity and specificity for individual coronary artery segments were as follows: proximal, 89% and 93%; medial, 87% and 90%; distal, 50% and 90%; and secondary branches, 62% and 92%. CONCLUSIONS Non-invasive coronary artery angiography with 16 multidetector-row computed tomography is a powerful diagnostic tool, especially for the evaluation of the proximal and medial segments of the major coronary arteries.

Improvement of myocardial function and perfusion after successful percutaneous revascularization in patients with chronic total coronary occlusion

BACKGROUND Percutaneous coronary intervention (PCI) for chronic total occlusion (CTO) of a coronary artery can provide benefits in terms of myocardial function and survival but the procedure is complex and the success rate is relatively low. To assess these benefits, myocardial function, ischemia and viability should be clearly determined by means of a reliable diagnostic test. This study aimed to assess ventricular function and myocardial ischemia before and after PCI for CTO using cardiac magnetic resonance (CMR). NYHA functional class was also assessed before and after PCI. METHODS AND RESULTS CMR studies were performed in 43 consecutive patients (7 females; aged 64 ± 9.6 y.o.) with CTO scheduled for PCI and repeated 6 months post-PCI. PCI was successful in 33 (77%) of them. In this group CMR had shown inducible perfusion defects in 26 (79%) before PCI, while they were observed in 10 (30%) post-PCI CMR study (p < 0.001). The number of segments showing inducible perfusion defect (3.4 ± 2 prevs. 2.9 ± 4.5 post-PCI, p = 0.002) was significantly reduced in this group. Regional contractile function of segments showing viability also improved significantly in the group with successful CTO PCI compared to the group with an unsuccessful procedure. NYHA functional class for angina also improved in patients with successful revascularization while it remained unchanged in the group with unsuccessful procedures. CONCLUSIONS A successful CTO PCI leads to a reduction in inducible myocardial ischemia and to an improvement in regional wall motion, which results in clinical improvement.

Determinantes del éxito de la revascularización de las oclusiones coronarias crónicas: estudio mediante tomografía computarizada con multidetectores

INTRODUCTION AND OBJECTIVES Percutaneous revascularization of chronic total coronary artery occlusion is a technical challenge and has a lower success rate than other angioplasty procedures. Identification of predictors of failure could lead to better selection of patients with the greatest possibility of success. In this study, we investigate the multidetector computed tomography features associated with failure of percutaneous treatment for chronic total coronary occlusion. METHODS This is a prospective, single-center study of 69 consecutive patients with chronic total occlusion in whom multidetector computed tomography study was performed before percutaneous coronary revascularization. RESULTS Seventy-seven lesions were analyzed. The mean length of the occlusion was 19.9 (14.3) mm and the estimated duration of occlusion was 47 (62) months. The only angiographic factor independently predictive of failure was a severe curve between the plaque and the proximal patent vessel (odds ratio 3.8, 95% confidence interval, 1.2-12; P=.02). On multidetector computed tomography, the only factor predictive of failure was an arc of calcium affecting more than 50% of the vessel circumference in the proximal (P=.04) and middle (P=.03) third of the occlusion. CONCLUSIONS Multidetector computed tomography identified a variable that cannot be measured by angiography that can predict failure in percutaneous revascularization of chronic total coronary occlusions. In selected cases, this parameter could be useful for preprocedure screening.

Delayed-contrast enhancement cardioresonance in transient left ventricular apical ballooning

Transient left ventricular apical ballooning (TAB) is a condition that mimics acute coronary syndrome typically without coronary angiographic stenosis. Patients present with typical chest pain, ECG changes suggesting ischemia, and a slight elevation of myocardial injury markers such as Creatine kinase and Troponines. Ballooning during ventricular systole of the cardiac apex is a characteristic feature of this entity. It is transient and it usually resolves after a few days together with normalization of ECG changes. Initially, apical dyskinesis can be diagnosed by any cardiac imaging technique that allows myocardial wall motion assessment. Recent advances in cardiovascular magnetic resonance imaging (CMR) have made this technique to become the gold-standard method to assess myocardial infarction. CMR provides an excellent and reproducible assessment of segmental wall motion abnormalities and, more importantly, it allows an accurate depiction of myocardial necrotic area by means of delayed contrast-enhancement method. Therefore, it may be particularly useful in the assessment of TAB by demonstrating segmental dysfunction in the absence of myocardial irreversible damage. We report three cases of TAB in which contrast- enhanced CMR emerged as an excellent diagnostic tool.

Translating the microRNA signature of microvesicles derived from human coronary artery smooth muscle cells in patients with familial hypercholesterolemia and coronary artery disease

AIMS To analyze the impact of atherogenic lipoproteins on the miRNA signature of microvesicles derived from human coronary artery smooth muscle cells (CASMC) and to translate these results to familial hypercholesterolemia (FH) and coronary artery disease (CAD) patients. METHODS Conditioned media was collected after exposure of CASMC to atherogenic lipoproteins. Plasma samples were collected from two independent populations of diagnosed FH patients and matched normocholesterolemic controls (Study population 1, N=50; Study population 2, N=24) and a population of patients with suspected CAD (Study population 3, N=50). Extracellular vesicles were isolated and characterized using standard techniques. A panel of 30 miRNAs related to vascular smooth muscle cell (VSMC) (patho-)physiology was analyzed using RT-qPCR. RESULTS Atherogenic lipoproteins significantly reduced levels of miR-15b-5p, -24-3p, -29b-3p, -130a-3p, -143-3p, -146a-3p, -222-3p, -663a levels (P<0.050) in microvesicles (0.1μm-1μm in diameter) released by CASMC. Two of these miRNAs, miR-24-3p and miR-130a-3p, were reduced in circulating microvesicles from FH patients compared with normocholesterolemic controls in a pilot study (Study population 1) and in different validation studies (Study populations 1 and 2) (P<0.050). Supporting these results, plasma levels of miR-24-3p and miR-130a-3p were also downregulated in FH patients compared to controls (P<0.050). In addition, plasma levels of miR-130a-3p were inversely associated with coronary atherosclerosis in a cohort of suspected CAD patients (Study population 3) (P<0.050). CONCLUSIONS Exposure to atherogenic lipoproteins modifies the miRNA profile of CASMC-derived microvesicles and these alterations are reflected in patients with FH. Circulating miR-130a-3p emerges as a potential biomarker for coronary atherosclerosis.

Impact of Multidetector Computed Tomography Noninvasive Coronary Angiography on Epidemiology: Toward Direct Evidence of Cardiovascular Risk

La cardiopatia isquemica es una de las enfermedades mas prevalentes en el mundo desarrollado, con elevada morbimortalidad que comporta la utilizacion de cuantiosos recursos economicos para combatirla. Se estima que una tercera parte de los infartos agudos de miocardio se presentan, sin antecedentes clinicos previos, en forma de muerte subita, y son muy pocos los casos que logran recibir asistencia medica para sobrevivir a tan grave circunstancia. Por otra parte, los pacientes que ingresan en el hospital por un sindrome coronario agudo requieren atencion medica superespecializada, y tampoco estan exentos de complicaciones graves a corto o medio plazo, hecho que se traduce en un elevado importe de la factura sanitaria. Ante tan dramatica situacion, es comprensible que haya una gran sensibilidad social y politica que justifique el gran numero de recursos destinados al tratamiento de la cardiopatia isquemica, pero como el gasto sanitario no puede ser ilimitado, se impone potenciar la investigacion para encontrar nuevos y mas refinados metodos de prevencion primaria de esta enfermedad, y que sobretodo sean efectivos en cada individuo. A mediados del siglo pasado se describio la relacion epidemiologica entre los actualmente bien reconocidos factores de riesgo cardiovascular (CV) y la ateromatosis coronaria, con el estudio de Framingham como referente internacional. La trascendencia sanitaria y economica que este hecho podia tener en el desarrollo de la cardiopatia isquemica acentuo el interes por las politicas de prevencion primaria. La Sociedad Europea de Cardiologia fue la impulsora de los estudios que permitieron conocer la prevalencia de la enfermedad CV en nuestro continente a escala regional e identificar la existencia de un gradiente noreste-suroeste de incidencia de enfermedad CV, mucho menor en los paises mediterraneos que en el norte de Europa. Paralelamente, en nuestro pais surgieron estudios epidemiologicos a escala local, como el RICORNA en Navarra, el MONICA-Catalunya o el registro REGICOR, que recientemente ha cumplido 35 anos de historia. A partir de los resultados obtenidos en

Coronariografía no invasiva mediante tomografía computarizada con multidetectores en pacientes con sospecha de enfermedad coronaria y ergometría no diagnóstica

BACKGROUND AND OBJECTIVE We aimed to establish the diagnostic and prognostic usefulness of noninvasive coronary angiography using multidetector computer tomography (MDCT) in patients with clinical suspicion of coronary artery disease (CAD) and a non-diagnostic exercise treadmill test result. PATIENTS AND METHOD Retrospective analysis in 33 patients evaluating the incidence of revascularization and hospitalization due to myocardial infarction or angina, and death. RESULTS There were obstructive lesions in 7 (21%), non-obstructive lesions in 18 (55%), absence of lesions in 6 (18%), and, finally, 2 patients (6%) had an MDCT deemed as non-evaluable. The follow-up was extended up to 21 (10) months. Events appeared in 5 (15%) patients: 4 myocardial revascularizations in the group with obstructive coronary stenosis, and 1 cardiovascular death in the group with non-obstructive coronary lesions. No events were recorded among those 6 patients without coronary lesions nor in those 2 with non-evaluable MDCT studies. CONCLUSIONS Patients with suspected CAD and a non-diagnostic exercise test present with a high prevalence of CAD when studied by MDCT and have a high incidence of cardiovascular events. The severity of stenosis as assessed by MDCT relates to cardiovascular events during the follow-up.