Josepa Mauri

Drug-Eluting Stent Thrombosis Results From the Multicenter Spanish Registry ESTROFA (Estudio ESpañol sobre TROmbosis de stents FArmacoactivos)

OBJECTIVES This study sought to assess the incidence, predictors, and outcome of drug-eluting stent(DES) thrombosis in real-world clinical practice. BACKGROUND The DES thromboses in randomized trials could not be comparable to those observed in clinical practice, frequently including off-label indications. METHODS We designed a large-scale, nonindustry-linked multicentered registry, with 20 centers in Spain. The participant centers provided follow-up data for their patients treated with DES, reporting a detailed standardized form in the event of any angiography-documented DES-associated thrombosis occurring. RESULTS Of 23,500 patients treated with DES, definite stent thrombosis(ST) developed in 301: 24 acute, 125 subacute, and 152 late. Of the late, 62 occurred >1 year(very late ST). The cumulative incidence was 2% at 3 years. Antiplatelet treatment had been discontinued in 95 cases(31.6%). No differences in incidences were found among stent types. Independent predictors for subacute ST analyzed in a subgroup of 14,120 cases were diabetes, renal failure, acute coronary syndrome, ST-segment elevation myocardial infarction, stent length, and left anterior descending artery stenting, and for late ST were ST-segment elevation myocardial infarction, stenting in left anterior descending artery, and stent length. Mortality at 1-year follow-up was 16% and ST recurrence 4.6%. Older age, left ventricular ejection fraction <45%, nonrestoration of Thrombolysis In Myocardial Infarction flow grade 3, and additional stenting were independent predictors for mortality. CONCLUSIONS The cumulative incidence of ST after DES implantation was 2% at 3 years. No differences were found among stent types. Patient profiles differed between early and late ST. Short-term prognosis is poor, especially when restoration of normal flow fails.

Thrombosis of Second-Generation Drug-Eluting Stents in Real Practice: Results From the Multicenter Spanish Registry ESTROFA-2 (Estudio Español Sobre Trombosis de Stents Farmacoactivos de Segunda Generacion-2)

OBJECTIVES This study sought to evaluate second-generation drug-eluting stent (DES) thrombosis in clinical practice. BACKGROUND First-generation DES are associated with a significant incidence of late thrombosis. There is paucity of data regarding real practice late thrombosis incidence and predictors with second-generation DES, zotarolimus-eluting stent (ZES), and everolimus-eluting stents (EES). METHODS A prospective, large-scale, non-industry-linked multicenter registry was designed. Complete clinical-procedural data and systematic follow-up of all patients treated with these stents was reported in a dedicated registry supported by the Spanish Working Group on Interventional Cardiology. RESULTS From 2005 to 2008, 4,768 patients were included in 34 centers: 2,549 treated with ZES, and 2,219 with EES. The cumulative incidence of definite/probable thrombosis for ZES was 1.3% at 1 year and 1.7% at 2 years and for EES 1.4% at 1 year and 1.7% at 2 years (p = 0.8). The increment of definite thrombosis between the first and second year was 0.2% and 0.25%, respectively. In a propensity score analysis, the incidence remained very similar. Ejection fraction (adjusted hazard ratio [HR]: 0.97; 95% confidence interval [CI]: 0.95 to -0.99; p = 0.008), stent diameter (adjusted HR: 0.37; 95% CI: 0.17to 0.81; p = 0.01) and bifurcations (adjusted HR: 2.1; 95% CI: 1.14 to 3.7; p = 0.02) emerged as independent predictors of thrombosis. In the subgroup of patients with bifurcations, the use of ZES was independently associated with a higher thrombosis rate (adjusted HR: 4; 95% CI: 1.1 to 13; p = 0.03). CONCLUSIONS In a real practice setting, the incidence of thrombosis at 2 years with ZES and EES was low and quite similar. The incidence of very late thrombosis resulted lower than was reported in registries of first-generation DES. In the subset of bifurcations, the use of ZES significantly increased the risk of thrombosis.

Predictive (un)distortion model and 3-D reconstruction by biplane snakes

This paper is concerned with the three-dimensional (3-D) reconstruction of coronary vessel centerlines and with how distortion of X-ray angiographic images affects it. Angiographies suffer from pincushion and other geometrical distortions, caused by the peripheral concavity of the image intensifier (II) and the nonlinearity of electronic acquisition devices. In routine clinical practice, where a field-of-view (FOV) of 17-23 cm is commonly used for the acquisition of coronary vessels, this distortion introduces a positional error of up to 7 pixels for an image matrix size of 512/spl times/512 and an FOV of 17 cm. This error increases with the size of the FOV. Geometrical distortions have a significant effect on the validity of the 3-D reconstruction of vessels from these images. We show how this effect can be reduced by integrating a predictive model of (un)distortion into the biplane snakes formulation for 3-D reconstruction. First, we prove that the distortion can be accurately modeled using a polynomial for each view. Also, we show that the estimated polynomial is independent of focal length, but not of changes in anatomical angles, as the II is influenced by the Earths magnetic field. Thus, we decompose the polynomial into two components: the steady and the orientation-dependent component. We determine the optimal polynomial degree for each component, which is empirically determined to be five for the steady component and three for the orientation-dependent component. This fact simplifies the prediction of the orientation-dependent polynomial, since the number of polynomial coefficients to be predicted is lower. The integration of this model into the biplane snakes formulation enables us to avoid image unwarping, which deteriorates image quality and therefore complicates vessel centerline feature extraction. Moreover, we improve the biplane snake behavior when dealing with wavy vessels, by means of using generalized gradient vector flow. Our experiments show that the proposed methods in this paper decrease up to 88% the reconstruction error obtained when geometrical distortion effects are ignored. Tests on imaged phantoms and real cardiac images are presented as well.

Rayleigh Mixture Model for Plaque Characterization in Intravascular Ultrasound

Vulnerable plaques are the major cause of carotid and coronary vascular problems, such as heart attack or stroke. A correct modeling of plaque echomorphology and composition can help the identification of such lesions. The Rayleigh distribution is widely used to describe (nearly) homogeneous areas in ultrasound images. Since plaques may contain tissues with heterogeneous regions, more complex distributions depending on multiple parameters are usually needed, such as Rice, K or Nakagami distributions. In such cases, the problem formulation becomes more complex, and the optimization procedure to estimate the plaque echomorphology is more difficult. Here, we propose to model the tissue echomorphology by means of a mixture of Rayleigh distributions, known as the Rayleigh mixture model (RMM). The problem formulation is still simple, but its ability to describe complex textural patterns is very powerful. In this paper, we present a method for the automatic estimation of the RMM mixture parameters by means of the expectation maximization algorithm, which aims at characterizing tissue echomorphology in ultrasound (US). The performance of the proposed model is evaluated with a database of in vitro intravascular US cases. We show that the mixture coefficients and Rayleigh parameters explicitly derived from the mixture model are able to accurately describe different plaque types and to significantly improve the characterization performance of an already existing methodology.

Double Antiplatelet Therapy After Drug-Eluting Stent Implantation Risk Associated With Discontinuation Within the First Year

OBJECTIVES The goal of this study was to assess the risk associated with double antiplatelet therapy (DAT) discontinuation, and specifically, temporary discontinuation, during the first year after drug-eluting stent (DES) implantation. BACKGROUND Doubts remain about the risk of temporary DAT discontinuation within 1 year after DES implantation. METHODS A total of 1,622 consecutive patients undergoing DES implantation at 29 hospitals were followed up at 3, 6, 9, and 12 months to record the 1-year antiplatelet therapy discontinuation (ATD) rate, the number of days without DAT, and the rate of 1-year major cardiac events. Cox regression was used to analyze the association between ATD considered as a time-dependent covariate and 1-year cardiac events. RESULTS One hundred seventy-two (10.6%) patients interrupted at least 1 antiplatelet drug during the first year after DES implantation, although only 1 during the first month. Most (n=111, 64.5%) interrupted DAT temporarily (median: 7 days; range: 5 to 8.5): 79 clopidogrel (31 temporarily), 38 aspirin (27 temporarily), and 55 both drugs (53 temporarily). Discontinuation was followed by acute coronary syndrome in 7 (4.1%; 95% confidence interval [CI]: 1.7 to 8.2), a similar rate of major cardiac events to that in patients without ATD (n=80; 5.5%; 95% CI: 4.4 to 6.8; p=0.23). ATD was not independently associated with 1-year major cardiac events (hazard ratio: 1.32 [95% CI: 0.56 to 3.12]). CONCLUSIONS ATD within the first year and beyond the first month after DES is not exceptional, is usually temporary, and does not appear to have a large impact on risk.

Statistical strategy for anisotropic adventitia modelling in IVUS

Vessel plaque assessment by analysis of intravascular ultrasound sequences is a useful tool for cardiac disease diagnosis and intervention. Manual detection of luminal (inner) and media-adventitia (external) vessel borders is the main activity of physicians in the process of lumen narrowing (plaque) quantification. Difficult definition of vessel border descriptors, as well as, shades, artifacts, and blurred signal response due to ultrasound physical properties trouble automated adventitia segmentation. In order to efficiently approach such a complex problem, we propose blending advanced anisotropic filtering operators and statistical classification techniques into a vessel border modelling strategy. Our systematic statistical analysis shows that the reported adventitia detection achieves an accuracy in the range of interobserver variability regardless of plaque nature, vessel geometry, and incomplete vessel borders

Registro Español de Hemodinámica y Cardiología Intervencionista. XVI Informe Oficial de la Sección de Hemodinámica y Cardiología Intervencionista de la Sociedad Española de Cardiología (1990-2006)

Se presentan los resultados del Registro de Actividad de la Seccion de Hemodinamica y Cardiologia Intervencionista de la Sociedad Espanola de Cardiologia del ano 2006. Se recogen los datos de 135 hospitales, de los cuales 125 realizan su actividad predominante en adultos y 10 atienden exclusivamente a pacientes pediatricos. Se realizaron 126.196 estudios diagnosticos, con 113.228 coronariografias, lo que representa un aumento del 7,6% respecto al ano 2005 y una tasa de 2.560 coronariografias/millon de habitantes. Se realizaron 57.041 procedimientos intervencionistas coronarios, con un incremento del 7,8% respecto al 2005 y una tasa de 1.293 intervenciones/millon de habitantes. Se implantaron 90.006 stents, de los cuales el 59,3% fueron farmacoactivos. Se llevaron a cabo 10.067 procedimientos de intervencionismo en el infarto agudo de miocardio, lo que supone un incremento del 20,6% respecto al ano anterior y representa el 17,6% del total de las intervenciones coronaries percutaneas. El intervencionismo no coronario mas frecuente se realiza en las cardiopatias congenitas del adulto, como el cierre de la comunicacion interauricular, que es el de mayor numero, 334 procedimientos. La valvuloplastia mitral, con 431 casos tratados, apenas presenta cambios respecto al anterior Registro, y su exito esta en el 93,6%. La via de acceso radial se usa cada vez mas y mantiene el aumento de anos anteriores. Es de destacar el alto grado de participacion de los diferentes centros en el actual Registro, que hace que sea un referente internacional de la actividad hemodinamica en nuestro pais.

Registro Español de Hemodinámica y Cardiología Intervencionista. XVII Informe Oficial de la Sección de Hemodinámica y Cardiología Intervencionista de la Sociedad Española de Cardiología (1990-2007)

Se presentan los resultados del Registro de Actividad de la Seccion de Hemodinamica y Cardiologia Intervencionista de la Sociedad Espanola de Cardiologia del ano 2007. Se recogen los datos de 129 hospitales que realizan su actividad predominante en adultos; de esos centros, 74 realizan actividad publica y 55, privada. Se realizaron 136.231 estudios diagnosticos, con 122.260 coronariografias, lo que representa un aumento del 7,9% respecto al ano 2006 y una tasa de 2.725 coronariografias/ millon de habitantes. Los procedimientos intervencionistas coronarios practicados fueron 60.457, con un incremento del 6% respecto al 2006 y una tasa de 1.347 intervenciones/millon de habitantes. Se implantaron 94.966 stents, de los que el 57,7% fueron farmacoactivos. Se llevaron a cabo 11.322 procedimientos de intervencionismo en el infarto agudo de miocardio, lo que supone un incremento del 12,5% respecto al ano anterior y el 18,7% del total de intervenciones coronarias percutaneas. El intervencionismo no coronario mas frecuente se realiza en las cardiopatias congenitas del adulto; el cierre de la comunicacion interauricular es el de mayor numero, con 334 procedimientos. La valvuloplastia mitral, con 367 casos tratados y una tasa de exito del 90,7%, es el procedimiento percutaneo valvular mas realizado. Este ano han avanzado los procedimientos de implante de valvulas percutaneas, pues se ha implantado 18 valvulas entre pulmonares y aorticas. La via de acceso radial alcanza el 40% tanto en el diagnostico como en el intervencionismo. Es de destacar el alto grado de participacion de los diferentes centros en el actual Registro, que hace que sea un referente internacional de la actividad hemodinamica en nuestro pais.

3D curve reconstruction by biplane snakes

Stent implantation for coronary disease treatment is a highly important minimally invasive technique that avoids surgery interventions. In order to assure the success of such an intervention, it is very important to determine the real length of the lesion as exactly as possible. Currently, lesion measures are performed directly from the angiography without considering the system projective parameters or, alternatively, from the 3D reconstruction obtained from a correspondence of points defined by the physicians. In this paper, we present a method for 3D vessel reconstruction from biplane images by means of deformable models. In particular, we study the known shortcoming of point-based 3D vessel reconstruction (no intersection of projective beams) and illustrate that by using snakes the reconstruction error is minimal. We validate out method by a computer-generated phantom, a real phantom and coronary vessels.

SRBF: SPECKLE REDUCING BILATERAL FILTERING

Speckle noise negatively affects medical ultrasound image shape interpretation and boundary detection. Speckle removal filters are widely used to selectively remove speckle noise without destroying important image features to enhance object boundaries. In this article, a fully automatic bilateral filter tailored to ultrasound images is proposed. The edge preservation property is obtained by embedding noise statistics in the filter framework. Consequently, the filter is able to tackle the multiplicative behavior modulating the smoothing strength with respect to local statistics. The in silico experiments clearly showed that the speckle reducing bilateral filter (SRBF) has superior performances to most of the state of the art filtering methods. The filter is tested on 50 in vivo US images and its influence on a segmentation task is quantified. The results using SRBF filtered data sets show a superior performance to using oriented anisotropic diffusion filtered images. This improvement is due to the adaptive support of SRBF and the embedded noise statistics, yielding a more homogeneous smoothing. SRBF results in a fully automatic, fast and flexible algorithm potentially suitable in wide ranges of speckle noise sizes, for different medical applications (IVUS, B-mode, 3-D matrix array US).