P3381Quantification of hypo-attenuated leaflet thickening after transcatheter aortic valve implantation - clinical relevance of HALT volume

Background

Hypo-attenuated leaflet thickening (HALT) is a recently recognized phenomenon following transcatheter aortic valve implantation (TAVI) and there is no consensus over the standardized assessment of HALT and its clinical relevance is poorly understood. We sought to determine the predictors and clinical significance of HALT volume.

Methods

Patients, who previously underwent TAVI between 2011 and 2016 were prospectively enrolled in the RETORIC (Rule out Transcatheter Aortic Valve Thrombosis with Post Implantation Computed Tomography) study, a single-center observational study. At inclusion cardiac computed tomography angiography (CTA), transthoracic echocardiography (TTE) and brain magnetic resonance imaging (MRI) was performed. HALT was volumetrically quantified on cardiac CTA images by segmenting the inner volume of the TAVI frame at the level of the leaflets and applying a threshold of −200 to 200 Hounsfield units. We evaluated the clinical predictors of HALT volume, and its association with ischemic brain MRI lesions (recent and chronic large vessel ischemic focuses, microbleed/microembolization, white matter or small vessel disease) and all-cause mortality.

Results

In total, we analyzed 111 patients with CoreValve bioprosthesis (56.7% female, mean age 80.3±7.4 years). A median of 19 [IQR: 11–29] months passed between TAVI procedure and enrollment. The mean HALT volume was 111.0±163.4 mm3. Current malignant disease, prosthesis implantation depth measured on CTA images acquired at inclusion, and aortic mean gradient and aortic valve area evaluated on TTE images at inclusion predicted HALT volume by univariate analysis (all p<0.05). After multivariate adjustment, aortic mean gradient remained a significant predictor of HALT volume (beta-coefficient: 11.5, 95% CI: 5.0–18.0; p<0.001). HALT volume was not associated with ischemic brain MRI lesions (all p>0.05) and did not predict all-cause mortality (median follow-up: 20 months [IQR: 18–23]; HR: 1.0; 95% CI: 1.0–1.0; p=0.15).

Volumetric quantification of HALT.

Conclusion

Aortic mean gradient was the only predictor independently associated with HALT volume. Our results suggest that TAVI valve function is negatively affected by HALT volume, however, we found no association of HALT volume with cerebrovascular ischemic lesions or increased risk for all-cause mortality.

P6183Diagnostic performance of coronary computed tomography angiography-derived fractional flow reserve in patients with acute myocardial infarction and moderate non-culprit coronary stenosis

Background

Revascularisation of significant non-culprit coronary lesions (NCL) may improve clinical outcome in patients with myocardial infarction and multi vessel disease, however management of moderate NCLs is still controversial. Dobutamine stress echocardiography (DSE) and invasive fractional flow reserve (FFR) are accepted methods to detect myocardial ischemia, nevertheless coronary CT angiography-derived fractional flow reserve (CT-FFR) is a new modality, which has not been widely investigated to date in patients with NCLs.

Purpose

Our aim was to determine the diagnostic performance of CT-FFR compared to DSE and invasive FFR.

Methods

In this prospective trial, DSE, FFR and CT-FFR were performed in every patient with MI and at least one moderate NCL (30–70% diameter stenosis by visual assessment). New or worsening wall motion abnormality in at least two contiguous myocardial segments on DSE, and FFR value<0.8 in invasive FFR and CT-FFR as well were determined as abnormal. In comparison, DSE and FFR were regarded as reference standard methods.

Results

Between March of 2017 and December of 2018, 51 patients (58.2±10.4 years, 74.5% male) were enrolled and 71 NCLs (40 LAD, 13 LCx, 18 RCA) were investigated. Dobutamine stress echocardiography, FFR and CT-FFR were positive in 30.9%, 32.3% and 22.5% of all lesions, respectively. FFR values were higher with CT-FFR compared to invasive FFR (0.85±0.11 vs. 0.83±0.08, p<0.05). Compared to DSE, sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV) and diagnostic accuracy of CT-FFR were 40.9%, 85.7%, 56.2%, 76.3% and 71.8%, respectively. The same values were 39.1%, 85.4%, 56.2%, 74.5% and 70.4% compared to invasive FFR, respectively. Correspondence of CT-FFR with DSE (k=0.29) and with FFR (k=0.27) was weak.

Conclusion

This is the first study that compares the three modalities in the evaluation of moderate NCLs. Our results demonstrated moderate diagnostic accuracy, excellent specificity, poor sensitivity and PPV and acceptable NPV of CT-FFR compared to DSE and FFR. At this stage, CT-FFR is probably not accurate enough to determine revascularisation strategy of moderate NCLs as a single non-invasive method.

Nutrition care quality indicators in hospitals and nursing homes: A systematic literature review and critical appraisal of current evidence

OBJECTIVE

Quality indicators (QIs) can be used to assess and improve the quality of care in health care institutions. Although QIs about nutrition care in hospitals and nursing homes have been used in studies, no systematic catalogue exists to date. This systematic literature review identifies nutrition care QIs in hospitals and nursing homes and maps them according to QI type, stakeholder level and nutrition care theme. We also assess the level of consensus between studies and critically appraise the QIs presented therein based on two conceptual frameworks.

METHODS

Ovid, Scopus and grey literature were searched from 1995 to 2016 including studies in English and German. Papers were considered if they presented, developed, assessed, rated or applied nutrition care QIs in hospitals or nursing homes. We used Donabedian's framework to define structure, process and outcome indicators, the WHO (World Health Organization) definition to describe stakeholder levels, and a structured table to map indicators within themes. Further, we used the Institute of Medicine (IOM) and the Organisation for Economic Cooperation and Development (OECD) frameworks' key dimensions to measure the conceptual quality of the QIs. Results are summarised and presented tabulated and narratively.

RESULTS

From 536 identified studies, 46 were included. Eight hundred and twenty-two QIs were extracted and mapped into 19 themes and 151 sub-themes. Half were process indicators (49%) and about a quarter were outcome (28%) and structure (23%) indicators, respectively. The vast majority (71%) targeted micro level, while 28% meso level and only 1% macro level information. The nutrition themes meals/mealtimes (12%), treatment (adherence) (12%), nutrition screening (7%), assessment (7%) and monitoring (7%) were most frequently covered. 69% of indicators were cited by more than one study. Most frequent framework dimensions were patient-centeredness (33%), timeliness (30%), validity (30%) and actionability/feasibility (30%).

CONCLUSION

The large number of nutrition care QIs in hospitals and nursing homes indicates the high interest in and importance of better nutrition care provision in institutions. However, the great variability indicates little consensus of the nutrition community on how to best assess and measure the quality of nutrition care. The limited methodological and conceptual validity of presented QIs and the low representation of QIs at macro and meso levels make international consensus finding complicated. Increased efforts including all stakeholder levels and using conceptual frameworks to define a limited number of key QIs with high methodological validity, actionability and stakeholder relevance are needed. Registration in clinicaltrials.gov: Identifier: NCT02820246.

Preservation of the soft protein corona in distinct flow allows identification of weakly bound proteins

Nanocarriers that are used for targeted drug delivery come in contact with biological liquids and subsequently proteins will adsorb to the nanocarriers' surface to form the so called 'protein corona'. The protein corona defines the biological identity and determines the biological response towards the nanocarriers in the body. To make nanomedicine safe and reliable it is required to get a better insight into this protein corona and, therefore, the adsorbed proteins have to be characterized. Currently, centrifugation is the common method to isolate the protein corona for further investigations. However, with this method it is only possible to investigate the strongly bound proteins, also referred to as 'hard protein corona'. Therefore, we want to introduce a new separation technique to separate nanoparticles including the soft protein corona containing also loosely bound proteins for further characterization. The used separation technique is the asymmetric flow field-flow fractionation (AF4). We were able to separate the nanoparticles with proteins forming the soft protein corona and were able to show that in our system only the hard protein corona directly influenced the cell uptake behavior.

STATEMENT OF SIGNIFICANCE

Currently, there is an ongoing debate whether only strongly bound proteins (hard corona) or also loosely bound proteins (soft corona) contribute to the biological identity of nanocarriers, because up to now isolation of the soft corona was not possible. Here, asymmetric flow field-flow fractionation was used to isolate nanoparticles with a preserved soft corona from the biological medium. This enabled the characterization of the soft corona composition and to evaluate its influence on cellular uptake. For our system we found that only the strongly bound proteins (hard corona) determined cell internalization. This method can now be used to evaluate the impact of the soft corona further and to characterize nanomaterials that cannot be separated from blood plasma by other means.