Stent diferido versus inmediato en pacientes con infarto de miocardio ST elevado y alta carga de trombo residual reclasificado en la lesión culpable

Resumen: Introducción: Un trombo intracorononario largo reclasificado es un predictor independiente de resultados adversos y no reflujo en el infarto agudo de miocardio con elevación del ST. Pacientes con mayor carga de trombo residual tienen peor disfunción microvascular y mayor daño miocárdico. Métodos: Evaluamos retrospectivamente a 833 pacientes que fueron a angioplastia primaria entre enero del 2011 y junio del 2016. La carga de trombo residual final fue reclasificada tras realizar el cruce de la guía, predilatación con balón o tromboaspiración, para restaurar y estabilizar un flujo TIMI 2-3. Las estrategias de stent diferido vs. stent inmediato fueron comparadas, siendo el objetivo primario la incidencia de no reflujo (TIMI ≤ 2, o TIMI 3 con TMP < 2). Resultados: Cuarenta y siete pacientes (6.8%) presentaron una alta carga trombo residual reclasificado. La coronaria derecha fue la arteria culpable en 34 casos. Hubo mayor frecuencia de ectasia coronaria en el grupo de stent diferido (p = 0.005). Se encontraron menores tasas de no reflujo en el stent diferido (36% vs. 58%), con una mayor frecuencia de un TMP 3 (p = 0.005). Tras la nueva cateterización un 56% quedó libre de stent en el grupo diferido y la anticoagulación oral les fue más frecuentemente indicada (p = 0.031). La tasa de eventos cardiacos adversos mayores fue similar entre los grupos. Hubo una tendencia a una mejor función ventricular izquierda en el grupo diferido (p = 0.056). Conclusiones: El stent diferido puede ser una alternativa eficiente en pacientes con IAM CEST y alta carga de trombo residual reclasificado, después de conseguir un flujo TIMI 2-3 estable. Abstract: Background: Reclassification of a large thrombus burden is an independent predictor of major adverse cardiac events and no-reflow in patients with ST- segment elevation myocardial infarction (STEMI). Patients with a greater residual thrombus burden have worse microvascular dysfunction and greater myocardial damage. Methods: A retrospective analysis was performed on 833 STEMI patients who underwent primary percutaneous coronary intervention. The final residual thrombus burden was reclassified after the lesion was wired, and a thrombus aspiration or balloon dilatation was performed to restore and stabilise a thrombolysis in myocardial infarction (TIMI) 2-3 flow. Deferred stenting (DEI) was compared with immediate stenting (ISI) group, and the primary outcome was the incidence of no-/slow-reflow (TIMI ≤ 2, or TIMI 3 with myocardial blush grade < 2). Results: Overall, 47 patients (6.8%) had a residual large thrombus burden reclassified. The right coronary artery was the culprit vessel in 34 cases. More patients had coronary ectasia in the DSI group (P=.005). Fewer patients in the DSI had no-/slow-reflow (36% vs. 58%), and the myocardial blush grade 3 was more frequent in the DSI group (P=.005). After repeat coronary angiography in the DSI group, stenting was not performed in 56%, and oral anticoagulation was more frequent in the follow-up (P=.031). Major cardiac adverse events were similar between groups. There was a tendency to better left ventricular function in the DSI group (P=.056). Conclusions: Deferred stenting may be an efficient option in STEMI patients with a residual large thrombus burden reclassified after achieving a stable TIMI 2-3 flow. Palabras clave: Infarto de miocardio ST elevado, Intervención coronaria percutánea primaria, Alta carga de trombo residual reclasificado, Stent diferido, México, Keywords: ST-segment elevation myocardial infarction, Primary percutaneous coronary intervention, Residual large thrombus burden reclassified, Deferred stent, Mexic

High sensitivity flat SiO2 fibres for medical dosimetry

We describe investigation of a novel undoped flat fibre fabricated for medical radiation dosimetry. Using high energy X-ray beams generated at a potential of 6 MV, comparison has been made of the TL yield of silica flat fibres, TLD-100 chips and Ge-doped silica fibres. The flat fibres provide competitive TL yield to that of TLD-100 chips, being some 100 times that of the Ge-doped fibres. Pt-coated flat fibres have then been used to increase photoelectron production and hence local dose deposition, obtaining significant increase in dose sensitivity over that of undoped flat fibres. Using 250 kVp X-ray beams, the TL yield reveals a progressive linear increase in dose for Pt thicknesses from 20 nm up to 80 nm. The dose enhancement factor (DEF) of (0.0150±0.0003) nm-1 Pt is comparable to that obtained using gold, agreeing at the 1% level with the value expected on the basis of photoelectron generation. Finally, X-ray photoelectron spectroscopy (XPS) has been employed to characterize the surface oxidation state of the fibre medium. The charge state of Si2p was found to lie on 103.86 eV of binding energy and the atomic percentage obtained from the XPS analysis is 22.41%