Parameter estimation of a meal glucose-insulin model for TIDM patients from therapy historical data.

The effect of meal on blood glucose concentration is a key issue in diabetes mellitus because its estimation could be very useful in therapy decisions. In the case of type 1 diabetes mellitus (T1DM), the therapy based on automatic insulin delivery requires a closed-loop control system to maintain euglycaemia even in the postprandial state. Thus, the mathematical modelling of glucose metabolism is relevant to predict the metabolic state of a patient. Moreover, the eating habits are characteristic of each person, so it is of interest that the mathematical models of meal intake allow to personalise the glycaemic state of the patient using therapy historical data, that is, daily measurements of glucose and records of carbohydrate intake and insulin supply. Thus, here, a model of glucose metabolism that includes the effects of meal is analysed in order to establish criteria for data-based personalisation. The analysis includes the sensitivity and identifiability of the parameters, and the parameter estimation problem was resolved via two algorithms: particle swarm optimisation and evonorm. The results show that the mathematical model can be a useful tool to estimate the glycaemic status of a patient and personalise it according to her/his historical data.

Cerebral Protection During MitraClip Implantation: Initial Experience at 2 Centers.

OBJECTIVES: This study sought to assess the feasibility and safety of using a filter-based cerebral protection system (CPS) during MitraClip implantation and to report on the histopathologic analysis of the captured debris. BACKGROUND: Stroke is one of the serious adverse events associated with MitraClip therapy. METHODS: Between July 2014 and March 2015, 14 surgical high-risk patients (age 75 ± 7 years; 7 men; median logistic EuroSCORE 21%) underwent MitraClip implantation employing cerebral protection with a dual embolic filter system. All patients had severe mitral regurgitation of predominantly functional origin. RESULTS: All procedures were successfully completed for both CPS deployment/retrieval and MitraClip implantation. A total of 28 filters (2 from each patient) were analyzed. Microscopically, debris was identified in all 14 patients. The most common tissue types were acute thrombus and small fragments of foreign material, which were found in 12 patients (85.7%) each. Organizing thrombus was present in 4 patients (28.6%), valve tissue and/or superficial atrial wall tissue in 9 patients (64.3%), and fragments of myocardium in 2 patients (14.3%). No transient ischemic attacks, strokes, or deaths occurred peri-procedurally or during a median follow-up interval of 8.4 months. CONCLUSIONS: In this small study of patients undergoing MitraClip treatment with cerebral protection, embolic debris potentially conducive to cerebrovascular events was found in all patients. Debris was composed most often of acute thrombus, foreign material likely originating from the hydrophilic device coating, and valve/atrial wall tissue. Further studies are warranted to assess the impact of cerebral protection on the incidence of cerebrovascular events after MitraClip therapy.

Pathological aspects of bioresorbable stent implantation.

The treatment of obstructive coronary artery disease has been revolutionised by the advent of drug-eluting stent therapy. However, concerns remain about complications late after stent implantation including late stent thrombosis, hypersensitivity reactions and neoatherosclerosis. In this respect, the introduction of fully bioresorbable stents (BRS)--which resorb over time and leave the arterial wall free of any metal constraints--represents a potentially important disruptive technology. However, although the concept is intuitively attractive, a thorough understanding of the histopathological changes seen after BRS implantation and an appreciation of comparative changes versus existing metal stent technologies are vital to guide BRS clinical usage. In this respect, translational investigation of polymer chemistry, biomedical engineering, as well as in vitro and in vivo testing in animal models is an important undertaking. This article will review the pathological aspects of BRS implantation with a focus on acute and chronic vascular reactions derived from preclinical animal studies, including insights from in vivo imaging. Finally, potential future directions of this novel therapeutic approach will be discussed.

The everolimus-eluting Xience stent in small vessel disease: bench, clinical, and pathology view.

Coronary artery disease (CAD) is the leading cause of morbidity and mortality worldwide. The pathogenesis of CAD relates to the presence of atherosclerotic plaques in the coronary arteries, which are most frequently treated today by percutaneous coronary intervention. Small vessel disease treatment represents one-third of all percutaneous coronary interventions with higher rates of restenosis and major adverse cardiac events. Initially, drug-eluting stents (DES) were developed to reduce in-stent restenosis, improving clinical outcomes and reducing the need for target vessel revascularization. However, late and very late stent thrombosis emerged as a new problem compromising DES's long-term results. The cobalt-chromium everolimus-eluting stent (CoCr-EES) represents the results of an evolutionary process in DES technology aimed at improving the shortcomings of first-generation DES. Small vessel CAD has historically been an obstacle to long-term patency following implantation of DES. Antirestenotic efficacy has been shown to be of high relevance in small vessels. Therefore, stent selection may play an important role in determining outcomes in this subgroup of patients. This article will review the performance of CoCr-EES in the treatment of small vessel CAD from preclinical, clinical, and pathology perspectives, and it will highlight the most important findings in this regard.

Expectations and limitations of contemporary intravascular imaging: lessons learned from pathology.

Acute coronary syndrome is the leading cause of death worldwide and plaque rupture is the most common underlying mechanism of coronary thrombosis. During the last 2 decades the understanding of atherosclerotic plaque progression advanced dramatically and pathology studies provided fundamental insights of underlying plaque morphology, which paved the way for invasive imaging modalities, which bring a new area of atherosclerotic plaque characterization in vivo. The development of intravascular ultrasound (IVUS) allowed the field to evaluate the principles of vascular anatomy, which is often underestimated by coronary angiography. Furthermore, IVUS image technologies were developed to obtain improved characterization of plaque composition. However, since spatial resolution of IVUS is insufficient to distinguish details of plaque morphology, a broad adoption of this technology in clinical practice was missing. Optical coherence tomography is a light-based imaging modality with higher spatial resolution compared to IVUS, which enables the assessment of vascular anatomy with great detail.