Estrategia simple o compleja para lesiones de bifurcaciones coronarias: evaluación inmediata de la aposición de los struts del stent mediante tomografía de coherencia óptica / Simple versus complex approaches to treating coronary bifurcation lesions: direct assessment of stent strut apposition by optical coherence tomography

Introducción y objetivos. La implantación de stents en lesiones de bifurcaciones coronarias comporta un riesgo elevado de deformación y mala aposición del stent. Las observaciones anatomopatológicas han atribuido a la mala aposición de los struts un papel causal en la elevada tasa de trombosis de los stents que se observa en las bifurcaciones. Métodos. Se evaluó la aposición de los struts en las lesiones de bifurcaciones tratadas con una técnica simple de implantación de stent solo en el vaso principal o con una técnica compleja (de culotte) mediante el empleo de tomografía de coherencia óptica (OCT). La mala aposición de un strut se definió por el hecho de que la distancia entre su superficie intraluminal y la pared vascular fuera superior a su grosor más un margen de error de resolución de la OCT de 15 μm. Resultados. En 17 pacientes se utilizó la estrategia simple y en 14, la técnica compleja (de culotte). Los struts con mala aposición fueron significativamente más frecuentes y la distancia entre el strut y la pared vascular en los casos de mala aposición fue mayor en la mitad de la bifurcación situada hacia la rama lateral (RL) (46,1% [35,3-62,5]) en comparación con la mitad del lado opuesto (9,1% [2,2-21,6]), el segmento distal (7,5% [2,3-20,2]) y el segmento proximal (12,6% [7,8-23,1]; p < 0,0001) (distancias, 98 μm [37-297] frente a 31 μm [13-74], 49 μm [20-100] y 38 μm [17-90], respectivamente; p < 0,0001). El empleo de la técnica compleja no afectó a la prevalencia de struts con mala aposición en los 4 segmentos en comparación con la estrategia simple (p = 0,31) y se asoció a una menor distancia strut-pared en el segmento proximal (47 frente a 60 mm; p = 0,0008). Conclusiones. En las lesiones de bifurcaciones coronarias, la mala aposición de los struts se produce con mayor frecuencia y es más importante en la zona de origen de la RL. El empleo de la técnica de culotte no aumenta de manera significativa la prevalencia de la mala aposición de los struts en comparación con una estrategia simple (AU)

Introduction and objectives. Stenting of coronary bifurcation lesions carries an increased risk of stent deformation and malapposition. Anatomical and pathological observations indicate that the high stent thrombosis rate in bifurcations is due to malapposition of stent struts. Methods. Strut apposition was assessed with optical coherence tomography (OCT) in bifurcation lesions treated either using the simple technique of stent implantation in the main vessel only or a complex technique (i.e. Culotte’s). A strut was regarded as malapposed if the gap between its endoluminal surface and the vessel wall was greater than its thickness plus an OCT resolution error margin of 15 µm. Results. Simple and complex (i.e. Culotte’s) approaches were used in 17 and 14 patients, respectively. Strut malapposition was significantly more frequent for the half of the bifurcation on same side as the vessel side branch (median, 46.1%; interquartile range [IQR], 35.3–62.5%) than for the half opposite the side branch (9.1%; IQR, 2.2–21.6%), the distal segment (7.5%; IQR, 2.3–20.2%) or the proximal segment (12.6%; IQR, 7.8–23.1%; P<.0001); the gap between strut and vessel wall in malapposed struts was significantly greater in the first segment than the others: 98 µm (IQR, 37–297 µm) vs. 31 µm (IQR, 13–74 µm), 49 µm (IQR, 20–100 µm) and 38 µm (IQR, 17–90 µm), respectively (P<.0001). Using the complex technique had no effect on the prevalence of strut malapposition in the four segments relative to the simple technique (P=.31) but was associated with a smaller gap in the proximal segment (47 µm vs. 60 µm; P=.0008). Conclusions. In coronary bifurcation lesions, strut malapposition occurred most frequently and was most significant close to the side branch ostium. The use of Culotte’s technique did not significantly increase the prevalence of strut malapposition compared with a simple technique (AU)

4-Guanidino-n-butyl syringate (Leonurine, SCM 198) protects H9c2 rat ventricular cells from hypoxia-induced apoptosis.

In the present study, we examined the ability of a chemically synthesized compound based on the structure of leonurine, a phytochemical component of Herba leonuri, to protect H9c2 rat ventricular cells from apoptosis induced by hypoxia and serum deprivation, as a model of ischemia. The results revealed a concentration-dependent increase in cell viability associated with leonurine treatment, accompanied by a consistent decline in lactate dehydrogenase leakage into the culture medium. The fraction of annexin V-fluorescein isothiocyanate-positive cells was increased by hypoxia but reduced by leonurine. These changes were associated with increased expression of the antiapoptotic gene, Bcl-2, and reduced expression of the proapoptotic gene, Bax. Leonurine also reduced the cytosolic Ca overload induced by hypoxia. These results suggest that leonurine elicits potent cardioprotective effects in H9c2 cells, and these effects may be mediated by inhibition of intracellular Ca overload and apoptosis during hypoxia.

Technology preview: X-ray fused with magnetic resonance during invasive cardiovascular procedures.

BACKGROUND: We have developed and validated a system for real-time X-ray fused with magnetic resonance imaging, MRI (XFM), to guide catheter procedures with high spatial precision. Our implementation overlays roadmaps-MRI-derived soft-tissue features of interest-onto conventional X-ray fluoroscopy. We report our initial clinical experience applying XFM, using external fiducial markers, electrocardiogram (ECG)- gating, and automated real-time correction for gantry and table movement. METHODS: This prospective case series for technical development was approved by the NHLBI Institutional Review Board and included 19 subjects. Multimodality external fiducial markers were affixed to patients' skin before MRI, which included contrast-enhanced, 3D T1-weighted, or breath-held and ECG-gated 2D steady state free precession imaging at 1.5T. MRI-derived roadmaps were manually segmented while patients were transferred to a calibrated X-ray fluoroscopy system. Image spaces were registered using the fiducial markers and thereafter permitted unrestricted gantry rotation, table panning, and magnification changes. Static and ECG-gated MRI data were transformed from 3D to 2D to correspond with gantry and table position and combined with live X-ray images. RESULTS: Clinical procedures included graft coronary arteriography, right ventricular free-wall biopsy, and iliac and femoral artery recanalization and stenting. MRI roadmaps improved operator confidence, and in the biopsy cases, outperformed the best available alternative imaging modality. Registration errors were increased when external fiducial markers were affixed to more mobile skin positions, such as over the abdomen. CONCLUSION: XFM using external fiducial markers is feasible during X-ray guided catheter treatments. Multimodality image fusion may prove a useful adjunct to invasive cardiovascular procedures.