RESUMO
Major cardiovascular events (MACEs) are a cause of major mortality worldwide. The narrowing and blockage of coronary arteries with atherosclerotic plaques are diagnosed and treated with percutaneous coronary intervention (PCI). During this procedure, coronary angiography (CAG) remains the most widely used guidance modality for the evaluation of the affected blood vessel. The measurement of the blood vessel diameter is an important factor to consider in order to decide if stent colocation is suitable for the intervention. In this regard, a small blood vessel (<2.75 mm) is majorly left without stent colocation; however, small vessel coronary artery disease (SvCAD) is a significant risk factor for the recurrence of MACEs, maybe due to the lack of a standardized treatment related to the diameter of the affected blood vessel; therefore, a more precise measurement is needed. The use of CAG for the measurement of the blood vessel diameter has some important limitations that can be improved with the use of newer techniques such as intravascular ultrasound (IVUS), although at higher costs, which might explain its underuse. To address differences in blood vessel diameter measurements and identify specific cases where IVUS might be of additional benefit for the patient, we conducted a retrospective study in patients who underwent PCI for MACEs with affection for at least one small blood vessel. We compared the measurements of the affected small blood vessels' diameter obtained by CAG and IVUS to identify cases of reclassification of the affected blood vessel; additionally, we underwent a multivariate analysis to identify risk factors associated with blood vessel reclassification. We included information from 48 patients with a mean ± SD age of 69.1 ± 11.9 years; 70.8% were men and 29.2% were women. The mean diameter with CAG and IVUS was 2.1 mm (95% CI 1.9-2.2), and 2.8 (2.8-3.0), respectively. The estimated difference was of 0.8 mm (95% CI 0.7-0.9). We found a significant positive low correlation in diameter measurements of small blood vessels obtained with CAG and IVUS (r = 0.1242 p = 0.014). In total, 37 (77%) patients had a reclassification of the affected blood vessel with IVUS. In 21 cases, the affected blood vessel changed from a small to a medium size (2.75-3.00 mm), and in 15 cases, the affected vessel changed from a small to a large size (<3.00 mm). The Bland-Altman plot was used to evaluate agreement in measurements with CAG and IVUS. The change in blood vessel classification with IVUs was important for the decision of intervention and stent collocation. The only variable associated with reclassification of blood vessels after adjustment in a multivariate analysis was T2D (type 2 diabetes) (p = 0 0.035). Our findings corroborate that blood vessels might appear smaller with CAG, especially in patients with T2D; therefore, at least in these cases, the use of IVUS is recommended over CAG.
RESUMO
Introducción: la experiencia clínica ha demostrado que el anillo de soporte de la bioprótesis valvular cardíaca (ASBVC) ejerce un importante papel en la operatividad del implante. Los resultados tras la utilización de múltiples modelos, han ampliado el estado del arte en el diseño y desarrollo de dichos anillos; aún así, no se logra un anillo que opere como el soporte natural. Dada la importancia del ASBVC, la fabricación en el ámbito nacional de bioprótesis valvular cardíaca (BVC) se ve limitada porque los fabricantes multinacionales sólo ponen a disposición el conjunto valvular bioprotésico, por lo que no se cuenta con el ASBVC aislado; además, pesa sobre éstos una patente que impide su réplica y prohibe su producción industrial. Objetivos: desarrollar un nuevo modelo de ASBVC, con mejores prestaciones, considerando los aspectos funcionales más relevantes para un soporte de alto comportamiento. Evaluar los diseños mediante técnicas computadorizadas y máquinas de pruebas especialmente construidas. Materiales y métodos: mediante técnicas de estática y dinámica, considerando variables de flexibilidad, distribución de cargas y tensión, y condiciones de operación, se hace un diseño conceptual de ASBVC. Luego se realiza un diseño geométrico dimensional teniendo en cuenta los aspectos anatómicos y el montaje del tejido biológico. Se selecciona un material que cumpla con los requerimientos de compatibilidad biológica, resistencia química y esfuerzos mecánicos a los que estará sometido el soporte de la BVC. Se evalúa la procesabilidad del material con tecnologías de fabricación rápida de prototipos, así como mediante técnicas de extrusión, maquinado o inyección de termoplásticos...