Atrial dimension reference values in healthy participants using the biplane/monoplane method for clinical and research use

AIM

To provide reference values of the dimensions of the left and right atrium (RA) obtained using the biplane and monoplane methods, respectively, on two- and four-chamber views, which represent the standard projections acquired in clinical practice, and correlation with body surface area (BSA), age, and gender.

MATERIALS AND METHODS

Healthy volunteers, M:F = 1:1, including five participants per gender and age decile from 20 to 70 years, who underwent cardiovascular magnetic resonance imaging (CMR) were enrolled prospectively. Normal atrial reference values were calculated for male and female subpopulations and stratified by age. Atrial areas and volumes were assessed both as absolute values and indexed to BSA. Differences among genders and correlation with age were assessed. Intra- and interobserver reproducibility were assessed in a subpopulation.

RESULTS

Fifty participants (mean age 43.3 ± 14 years, 25 men) were evaluated. Image analysis took <1 minute for each subject (mean time 30 ± 5 seconds). Intra- and interobserver reproducibility were excellent (ICC >0.85 for all datasets). RA areas were significantly higher in males (p=0.0001). The left atrial (LA) surface did not show significant differences among genders. Atrial areas normalised to BSA did not show significant gender differences. Both right and left absolute atrial volumes turned out to be significantly higher in males (p=0.0001 and p=0.0047, respectively), and normalised to BSA remained significantly different only for the RA (p=0.0006). Neither atrial volume nor areas showed significant correlation with age.

CONCLUSIONS

The monoplane method is a fast and reproducible technique to assess atrial dimensions. Absolute atrial dimensions show significant variations among genders. Gender-specific reference ranges for atrial dimensions are recommended.

Systematic review of early warning signs of relapse and behavioural antecedents of symptom worsening in people living with schizophrenia spectrum disorders

BACKGROUND

Identification of the early warning signs (EWS) of relapse is key to relapse prevention in schizophrenia spectrum disorders, however, limitations to their precision have been reported. Substantial methodological innovations have recently been applied to the prediction of psychotic relapse and to individual psychotic symptoms. However, there has been no systematic review that has integrated findings across these two related outcomes and no systematic review of EWS of relapse for a decade.

METHOD

We conducted a systematic review of EWS of psychotic relapse and the behavioural antecedents of worsening psychotic symptoms. Traditional EWS and ecological momentary assessment/intervention studies were included. We completed meta-analyses of the pooled sensitivity and specificity of EWS in predicting relapse, and for the prediction of relapse from individual symptoms.

RESULTS

Seventy two studies were identified including 6903 participants. Sleep, mood, and suspiciousness, emerged as predictors of worsening symptoms. Pooled sensitivity and specificity of EWS in predicting psychotic relapse was 71% and 64% (AUC value = 0.72). There was a large pooled-effect size for the model predicting relapse from individual symptom which did not reach statistical significance (d = 0.81, 95%CIs = -0.01, 1.63).

CONCLUSIONS

Important methodological advancements in the prediction of psychotic relapse in schizophrenia spectrum disorders are evident with improvements in the precision of prediction. Further efforts are required to translate these advances into effective clinical innovations.

Bioconjugation of COL1 protein on liquid-like solid surfaces to study tumor invasion dynamics

Tumor invasion is likely driven by the product of intrinsic and extrinsic stresses, reduced intercellular adhesion, and reciprocal interactions between the cancer cells and the extracellular matrix (ECM). The ECM is a dynamic material system that is continuously evolving with the tumor microenvironment. Although it is widely reported that cancer cells degrade the ECM to create paths for migration using membrane-bound and soluble enzymes, other nonenzymatic mechanisms of invasion are less studied and not clearly understood. To explore tumor invasion that is independent of enzymatic degradation, we have created an open three-dimensional (3D) microchannel network using a novel bioconjugated liquid-like solid (LLS) medium to mimic both the tortuosity and the permeability of a loose capillary-like network. The LLS is made from an ensemble of soft granular microgels, which provides an accessible platform to investigate the 3D invasion of glioblastoma (GBM) tumor spheroids using in situ scanning confocal microscopy. The surface conjugation of the LLS microgels with type 1 collagen (COL1-LLS) enables cell adhesion and migration. In this model, invasive fronts of the GBM microtumor protruded into the proximal interstitial space and may have locally reorganized the surrounding COL1-LLS. Characterization of the invasive paths revealed a super-diffusive behavior of these fronts. Numerical simulations suggest that the interstitial space guided tumor invasion by restricting available paths, and this physical restriction is responsible for the super-diffusive behavior. This study also presents evidence that cancer cells utilize anchorage-dependent migration to explore their surroundings, and geometrical cues guide 3D tumor invasion along the accessible paths independent of proteolytic ability.

Implementation of a collaborative online international learning program in nursing education: protocol for a mixed methods study

BACKGROUND

An essential component of becoming a professional nurse is a perspective of global health issues and an awareness of diverse populations. Collaborative online international learning (COIL) using digital technologies, offers meaningful and rewarding opportunities to develop international partnerships between nurses from other countries, without economic, organisational or geographical barriers. Despite reported advantages of using COIL, few COIL interventions have been identified in the nursing literature. The aims of this study are to develop, implement and evaluate a COIL program between Australian and Canadian pre-registration nursing students.

METHODS

The study will utilize a mixed methods approach incorporating pre and post-test surveys, focus groups, and semi-structured interviews of key stakeholders. The design will adhere to The State University of New York (SUNY) COIL's criteria for intercultural/international learning opportunities. Participants will be recruited from nursing programs at an Australian Training and Further Education Institute and a Canadian college. Bennett's stages of intercultural competence will provide the theoretical framework for the research. Four specific research interventions will be developed for this project. For students, there will be an online virtual community to allow students and teachers to communicate, socially connect and share resources with each other. Virtual reality simulations will be employed within a virtual global classroom to promote collaborative, intercultural learning. For faculty, a virtual community of practice will provide a platform for faculty to share education and research ideas and participate in collaborate research opportunities.

DISCUSSION

This study will evaluate the outcomes of a nursing COIL program. It will measure participants' views on COIL, its contribution to student learning, changes in cultural awareness, organisational impact and research productivity. It will provide nursing students with the opportunity to become global leaders in nursing care and for faculty to develop international research skills and outputs. The findings from the study will allow further refinement of future nursing COIL programs.

Cardiovascular magnetic resonance in autoimmune rheumatic diseases: a clinical consensus document by the European Association of Cardiovascular Imaging

Autoimmune rheumatic diseases (ARDs) involve multiple organs including the heart and vasculature. Despite novel treatments, patients with ARDs still experience a reduced life expectancy, partly caused by the higher prevalence of cardiovascular disease (CVD). This includes CV inflammation, rhythm disturbances, perfusion abnormalities (ischaemia/infarction), dysregulation of vasoreactivity, myocardial fibrosis, coagulation abnormalities, pulmonary hypertension, valvular disease, and side-effects of immunomodulatory therapy. Currently, the evaluation of CV involvement in patients with ARDs is based on the assessment of cardiac symptoms, coupled with electrocardiography, blood testing, and echocardiography. However, CVD may not become overt until late in the course of the disease, thus potentially limiting the therapeutic window for intervention. More recently, cardiovascular magnetic resonance (CMR) has allowed for the early identification of pathophysiologic structural/functional alterations that take place before the onset of clinically overt CVD. CMR allows for detailed evaluation of biventricular function together with tissue characterization of vessels/myocardium in the same examination, yielding a reliable assessment of disease activity that might not be mirrored by blood biomarkers and other imaging modalities. Therefore, CMR provides diagnostic information that enables timely clinical decision-making and facilitates the tailoring of treatment to individual patients. Here we review the role of CMR in the early and accurate diagnosis of CVD in patients with ARDs compared with other non-invasive imaging modalities. Furthermore, we present a consensus-based decision algorithm for when a CMR study could be considered in patients with ARDs, together with a standardized study protocol. Lastly, we discuss the clinical implications of findings from a CMR examination.

The evaluation of tactile dysfunction in the hand in type 1 diabetes: a novel method based on haptics

AIMS

We present an innovative method based on haptics for the evaluation of the sense of touch in the hand, in people affected by type 1 diabetes.

METHODS

Forty individuals affected by diabetes and 20 healthy controls took part in the study; the diabetes group was further divided into two subgroups based on vibration sensitivity in the lower limb. By means of a novel haptic device, tactile sensitivity in the fingertip was measured as the ability of the participants to discriminate slip motion speed.

RESULTS

Tactile sensitivity was significantly lower in individuals affected by diabetes as compared to controls. Depending on the subgroup, the difference from the controls was equal to 0.11 (95% CI from 0.029 to 0.186) and to 0.267 (95% CI from 0.198 to 0.336). Within the diabetes group, tactile sensitivity correlated with vibration sensitivity in the upper (p = 0.001) and lower limb (p = 0.003). A significant relationship between nerve conduction parameters and tactile sensitivity was found (p = 0.03). Finally, we combined the different predictors (clinical, vibratory and electroneurography data) by using cluster analysis; tactile sensitivity was found to be significantly different between different clusters (p = 0.004).

CONCLUSIONS

Early signs of tactile dysfunction in the hand were found in individuals affected by diabetes, even in absence of diabetic neuropathy. The protocol presented in this study is a promising tool for the assessment of tactile dysfunction in the hand in people affected by type 1 diabetes.

Myocardial T2 values by a segmental approach with healthy ageing and gender

Funding Acknowledgements

Type of funding sources: None.

Introduction. No data are available in literature about normal ranges for T2 in human myocardium using GE scanners.

Aims. Our aims were to obtain myocardial regional and global T2 values as a reference for normality for the first time using a GE scanner and to assess their association with physiological variables.

Methods. A stratified approach was adopted for healthy volunteers recruitment, ensuring the presence of 10 participants for both genders in each age decile:  20–30, 30–40, 40-50, 50-60, 60-70 years. Basal, medium, and apical short-axis slices of the left ventricle were acquired by a multi-echo fast-spin-echo (MEFSE) sequence. Image analysis was performed with a commercially available software package. T2 value was assessed in all 16 myocardial segments and global value was the mean.

Results. The global T2 value averaged across all subjects was 52.2 ± 2.5 ms (range: 47.0-59.9 ms).

Inter-study, intra-observer, and inter-observer reproducibility was good (coefficient of variation &lt; 5%).

The 3.6% of segments was excluded because of artifacts and/or partial-volume effects. Segmental T2 values differed significantly (P &lt; 0.0001), with the lowest value in the basal anterolateral segment (50.0 ± 3.5 ms) and the highest in the apical lateral segment (54.9 ± 5.1 ms). Mean T2 was significantly lower in the basal slice compared to both medium (51.0 ± 2.4  vs 51.8 ± 2.6 ms; P &lt; 0.0001) and apical slices (51.0 ± 2.4  vs 54.2 ± 3.7 ms; P &lt; 0.0001), and in the medium slice than in the apical slice (51.8 ± 2.6  vs 54.2 ± 3.7 ms; P &lt; 0.0001).

Aging was associated with increased segmental and global T2 values. Females showed higher T2 values than males. T2 values were not correlated to heart rate.

Mean T2 values, standard deviation, and lower and upper limits of normal for all 16 myocardial segments are shown in Figure 1 for males and in Figure 2 for females, considering separately each age group.

Conclusion. The optimized MEFSE sequence allows for robust, reliable, and reproducible quantification of segmental T2 values. T2 values differ among myocardial slices and are influenced by age and gender, making mandatory to define gender- and age-specific segmental reference values for distinguishing between healthy and diseased myocardium. The normal ranges defined in this study on a large cohort of healthy subjects could be used as reference by other sites using the same sequence, allowing them to recruit a smaller population and accelerating the spread of myocardial T2 mapping in the clinical arena.

Changes in CMR parameters and prediction of cardiac complications in thalassemia major: fibrosis tells us more than iron

Funding Acknowledgements

Type of funding sources: Private company. Main funding source(s): The MIOT project received “no-profit support” from industrial sponsorships (Chiesi Farmaceutici S.p.A. and ApoPharma Inc.).

Background

Cardiovascular magnetic Resonance (CMR) has dramatically changed the clinical practice and improved the prognosis in thalassemia major (TM).

Aim

This is the first study evaluating the predictive value of changes in CMR parameters (myocardial iron, function, and fibrosis) for cardiac complications in TM.

Methods

We followed prospectively 709 TM patients (374 females; 29.77 ± 8.53 years) consecutively enrolled in the Myocardial Iron Overload in Thalassemia (MIOT) Network who performed a baseline and a 1st follow up CMR scan after 18 months.  Myocardial iron overload (MIO) was measured by multislice multiecho T2* technique and atrial dimensions and biventricular function by cine images. Macroscopic myocardial fibrosis was detected by late gadolinium enhancement technique.

Risk classes were defined based on  the 4 patterns of MIO from worst to normal. For patients with baseline MIO (at least one segmental T2*&lt;20 ms), improvement was defined as a transition to a better risk class, stabilization as no change in risk class, and worsening as a transition to a worse risk class. For patients without baseline MIO, the worsening was the transition to a worse risk class.

The percentage change was used for continuous variables. For biventricular ejection fractions, improvement was a %change &gt; 10%, stabilization a %change between -10% and 10%, and worsening a %change&lt;-10%. For biventricular volumes, LV mass index, and atrial areas, improvement was a % change&lt;-10%, stabilization a % change between -10% and 10%, and worsening a % change &gt; 10%.

Myocardial fibrosis was considered absent if not detected in any of the two CMRs and present if detected in at least one examination.

Results

During a mean follow-up of 89.4 ± 33.3 months, cardiac events were recorded in 50 (7.1%) patients: 24 (48%) episodes of heart failure, 24 (48%) arrhythmias (23 supraventricular and 1 hypokinetic), and 2 (4.0%) pulmonary hypertension.  Mean time from the 1st follow up CMR to the development of a cardiac complication was 75.31 ± 35.35 months.

In the univariate Cox regression analysis, cardiac iron cleareance and myocardial fibrosis were identified as univariate prognosticators (Table 1). In the multivariate analysis only myocardial fibrosis remained an independent predictor factor.

Conclusion

The presence of myocardial fibrosis at the baseline CMR or developed within 18 months emerges as the strongest long-term predictor for cardiac complications in TM. Our data demonstrate the importance in using the contrast medium for CMR scans in thalassemia patients.

Impact of the COVID-19 pandemic in the MR availability for iron overloaded patients

Funding Acknowledgements

Type of funding sources: Private company. Main funding source(s): The E-MIOT project receives “no-profit support” from industrial sponsorships (Chiesi Farmaceutici S.p.A. and Bayer).

Background

The T2* magnetic resonance imaging (MRI) technique for the noninvasive quantification of iron overload has significantly improved the survival of patients with hemoglobinopathies by tailoring the chelation therapy. In Italy, the E-MIOT (Extension-Myocardial Iron Overload in Thalassemia) Network, a collaborative project among MRI and hematological centers, has assured high-quality quantification of iron in vital organs such as heart, liver, and pancreas. The COVID-19 pandemic has disrupted healthcare services around the world, also leading to postpone  or delete deferable diagnostic evaluations.

Aim

  We evaluated the impact of the COVID-19 pandemic on MRI services for iron overload quantification in Italy.

Methods

The activity of the MRI centers of the E-MIOT Network in the year 2020 was compared to the activity in the same months of 2019. A specific survey was filled out by the MRI operators to evaluate if the availability of MRI slots for patients with hemoglobinothies was reduced and the reasons.

Results

In comparison with the year 2019, in 2020 there was a significant reduction in the number of T2* MRIs performed (350 vs 656; P < 0.0001). The comparison month by month between the two years highlighted a marked decline (86.9%) in the four-month period March-June 2020, a reduction in the gap between the two years in the three-month period July-September, and a new decline (41.4%) in the three-month period October-December (Figure 1). No patient with hemoglobinopathy could undergo an MRI scan during the Italian lockdown (9 March-10 May 2020).

Figure 2 shows the percentage of  decline (year 2020 vs 2019) in the number of T2*MRI scans for each MRI center. If no decline or an increase were present, the vertical axis was set at 0. All centers experienced a significant drop in the number of the T2* MRIs in the four-month period March-June (from 75 to 100%). In the three-month period July-September only the centers of Pisa and Taranto dropped the number of T2* MRIs due to the rescheduling of the other MRI appointments deleted during the lockdown. In the three-month period October-December a reduction of the T2* MRI scans was experienced by all centers, except for Campobasso. In the centers of Ferrara and Lamezia Terme the reduction was the consequence of the general reduction in the number of the total MRIs scheduled per day for the  sanitation procedures. In the other centers, the availability for T2* MRI scans was unchanged in comparison to 2019, but the patients refused the MRI follow up for fear of getting sick of COVID.

Conclusion

The COVID-19 pandemic is having a strong negative impact on the quantification of iron overload by MRI, which may seriously worsen the prognosis of patients with hemoglobinopathies. Strategies to ensure proved lifesaving MRI exam and to reassure patients about the health safety of the hospitals are recommended.

Influence of cardiac phase on myocardial native T1 values by a segmental approach

Funding Acknowledgements

Type of funding sources: None.

Background. Native T1 values are usually assessed in the end-diastole to minimize motion artifacts while the systolic data acquisition offers the advantage of a thicker myocardium, with reduced partial-volume effects. Higher myocardial T1 values have been detected in diastole at both 1.5T and 3T but the dependence of this difference on myocardial segments or gender has not been fully explored.

Aim. We provided a systematic comparison of myocardial native T1 values in diastole and systole, by considering separately myocardial segments and dividing males and females.

Methods. Sixty-one healthy subjects (46.0 ± 14.1 years, 32 males) underwent CMR at 1.5T (Signa Artist; GE Healthcare). Three short-axis slices of the left ventricle acquired in diastole and systole using a Modified Look–Locker Inversion Recovery sequence. Image analysis was performed with a commercially available software package. T1 value was assessed in all 16 myocardial segments and global value was the mean.

Results. Table 1 shows the comparison between T1 values calculated from maps obtained in diastole and systole. Systolic T1 values were significantly lower in the basal anterolateral segment, in all medium segments except for the medium inferior segment, and in all apical segments. The percentage difference between diastolic and systolic T1 values was considered to compensate for the higher T1 values in females, and a significantly higher value was detected in females for the majority of medium segments, for all apical segments, and for the global value.

Conclusion. The diastolic-systolic discrepancy was more pronounced for the females and at the apical level, supporting the hypothesis that, besides the physiologic variations in myocardial blood volume during the cardiac cycle, the partial volume-effect may be a strong additional contributing factor. Native T1 values should be obtained always in the same cardiac phase to avoid a potential bias in the discrimination between healthy and pathologically affected myocardium.

Normal CMR bi-atrial and biventricular reference values in sickle cell disease patients without heart damage

Funding Acknowledgements

Type of funding sources: Private company. Main funding source(s): The MIOT project receives “no-profit support” from industrial sponsorships (Chiesi Farmaceutici S.p.A., ApoPharma Inc.).

Background. Cardiac function indices in patients with hemoglobinopathies are different from those in healthy population, mainly due to chronic anemia. Normal reference values specific for SCD patients are not available by CMR.

Aim. We aimed to define the normal cut-off value in SCD patients for bi-atrial and biventricular cardiac magnetic resonance (CMR) parameters.

Methods. We considered forty-eight adult SCD patients with no known risk factors or cardiac disease, normal electrocardiogram, no macroscopic myocardial fibrosis, and all cardiac segments with T2*≥20 ms, consecutively enrolled in the MIOT network (Myocardial iron overload in thalassemia). SCD patients were compared with ninety-six healthy controls and 96 thalassemia major (TM) patients without cardiac damage, both matched for age and gender. Nine pediatric SCD patients were also analysed in comparison with 9 TM patients and 9 healthy subjects matched for age and gender. Cine images were acquired to quantify biventricular function parameters: LV and RV end-diastolic volume (EDV), end-systolic volume (ESV) and stroke volume (SV) were normalized for body surface area (EDVI, ESVI, SVI), as well as biventricular mass and atrial areas. Myocardial iron overload was assessed by segmental T2* technique. Late gadolinium enhancement (LGE) images were acquired for evaluation of macroscopic myocardial fibrosis.

Results. In all three groups males showed higher biventricular volumes and mass indexes than females. SCD male patients had significantly higher LVEDVI (p &lt; 0.0001), LVESVI (p = 0.010), LVSVI (p = 0.003), cardiac index (p = 0.002), LV and RV mass index  (p = 0.008 and p = 0.001, respectively) and left and right atrial areas (p &lt; 0.001 and p = 0.011) than healthy subjects. No significant differences were found in RVEDVI, EVESVI and biventricular EF. Compared to healthy volunteers, females with SCD showed a larger LVEDVI (p = 0.020), LVSVI (p = 0.039), RV mass index (p = 0.002) and left atrial area (p = 0.008).

SCD and TM patients showed comparable values of bi-atrial and biventricular volumes and function. When compared to TM, SCD patients showed a larger LV (p &lt; 0.001) and RV mass index (p = 0.001) in male group and a larger RV mass index (p = 0.001) in female group. Table 1 shows the cut-offs for bi-atrial and biventricular MR parameters for adult SCD patients by gender.

No significant differences in MR parameters were found among the pediatric groups.

Conclusions. Normal reference ranges of bi-atrial and biventricular MR parameters for adult males and females SCD patients were established. The use of these reference values will prevent possible misdiagnosis of cardiomyopathy in patients with SCD.

Parental subjective wellbeing during the COVID-19 lockdown: Evidence from the epicenter of a pandemic crisis

Introduction

The Coronavirus disease (COVID-19) health emergency has led national states to adopt severe actions forcing many people to cope with new and unexpected challenges. Those constraints risked to jeopardized the mental health and subjective wellbeing (SWB) of individuals.

Objectives

The present cross-sectional quantitative study explored whether and to what extent psychological and social aspects were determinants of parental SWB as outcome variable during the COVID-19 lockdown.

Methods

The sample was composed of 304 Italian parents (93% female, mean age 41.5, 91% from Lombardy). Data were gathered through Computer Assisted Web Interview (CAWI) four weeks after the beginning of the national lockdown. World Health Organization (WHO) wellbeing scale along with other self-reported measures of social support, feelings of abandonment, feeling of being equipped and adequacy of living spaces were administered. Data were analyzed by hierarchical regression models (Ethics Committee of Milano-Bicocca University approval N.0034537/20)

Results

According to the WHO cutoff score, 37.7% of parents reported low well-being levels. The regression model (F=11.2, p<.001) suggested that the feeling of abandonment and the feeling of being equipped were the most important contributors to SWB. Other statistically significant (but with lower effect sizes) variables were the support received by the partner and the adequacy of living spaces.

Conclusions

The findings bear out the pivotal importance of subjective states (such as feelings of abandonment or perceptions of being poorly equipped) in relation to the levels of parental SWB during the COVID-19 lockdown. Implications for planning psychological interventions aimed at strengthening personal resources to face the emergency are discussed.

Disclosure

No significant relationships.

Myocardial native T1 mapping and correlations with clinical and CMR parameters in patients with systemic sclerosis

Funding Acknowledgements

Type of funding sources: None.

Background

Systemic sclerosis (SSc) is a connective tissue disease characterized by diffuse vascular lesions and fibrosis, also affecting the heart. Cardiovascular magnetic resonance (CMR) can detect replacement myocardial fibrosis by late gadolinium enhancement (LGE) and interstitial myocardial fibrosis/edema by T1 mapping techniques.

Purpose

To evaluate the prevalence of cardiac involvement by native T1 mapping and its correlation with clinical and CMR parameters in SSc patients.

Methods

Fifty-one consecutive SSc patients (mean age 51.8 ± 13.7 years, 42 females) and 51 healthy subjects matched for age and sex underwent clinical, bio-humoral assessment, and CMR at 1.5T (Signa Artist, GE Healthcare ). The imaging protocol included: cine, T1 mapping by MOLLI, T2 mapping by multi-echo fast-spin-echo sequence, LGE, and STIR T2-weighted sequences. Native T1 and T2 values were assessed in all 16 myocardial segments and the global value was the mean.

Results. Global native T1 values were significantly higher in SSc patients than in healthy subjects (1076.4 ± 50.7 vs 1033.3 ± 31.9 ms; P &lt; 0.0001).

As in healthy subjects, in patients native T1 values were significantly lower in males than in females (1033.4 ± 38.3 vs 1085.6 ± 48.6 ms; P = 0.004) and inversely correlated with age (R=-0415; P = 0.002).

Twenty-three (45.1%) patients had an increased global heart T1 value (&gt;1060 ms in males and &gt;1085 ms in females). Of them, 14 patients (60.9 %) showed positive LGE. Frequency of cardiovascular risk factors, indices of disease activity and chronicity, biochemical parameters, and cardio-active therapy were comparable between patients with normal and elevated T1. Compared to patients with normal T1 value, patients with elevated T1 had significantly higher left ventricular (LV) end-diastolic volume index (76.8 ± 13.3 vs 69.2 ± 11.8, P = 0.050), LV stroke volume index (49.7 ± 6.4 vs 44.4 ± 6.9 ml/m2; P = 0.010), LV cardiac output (3.6 ± 0.5  vs 3.0 ± 0.6 l/min /m2; P &lt; 0.0001), and global heart T2 values (60.1 ± 3.6 vs 55.7 ± 3.1 ms; P &lt; 0.0001).

Replacement myocardial fibrosis was detected in 24 (47.1%) patients and they showed significantly higher global heart native T1 values (Figure 1A).

Positive T2-weighted images for myocardial oedema were found in 5 (9.8%) patients, all with increased global heart native T1 value. Patients with oedema had significantly higher native global heart T1 values (Figure 1B).

Conclusion

Elevated native T1 values measured by CMR are frequent in SSc patients and they are associated with inflammation, replacement fibrosis, and increased LV dimension. CMR T1 mapping seems to be a sensitive parameter to include in the routine clinical assessment of SSc patients for detecting earlier pejorative cardiac involvement, although prospective data are recommended.

Abstract Figure.

Late Gadolinium Enhancement at cardiac magnetic resonance predicts malignant ventricular arrhythmias in systemic sclerosis

Background

Malignant arrhythmias due to cardiac involvement are a frequent cause of death in systemic sclerosis (SSc). Cardiac involvement, which is linked to both ischaemic and non-ischaemic fibrotic deposition, is often subclinical. Cardiovascular magnetic resonance (CMR) is the non-invasive gold standard for myocardial tissue characterization and can detect macroscopic myocardial fibrosis through late Gadolinium enhancement (LGE).

Aim

To evaluate the role of LGE to predict malignant arrhythmias requiring implantable cardioverter defibrillator (ICD) in SSc.

Methods

289 SSc patients underwent a thorough clinical evaluation and CMR exam using a 1.5 T scanner. Biventricular function parameter by SSFP cine images, oedema by STIR T2 images, and macroscopic fibrosis by LGE were assessed. Patients were followed-up and malignant ventricular arrhythmias requiring ICD implantation was considered as event.

Results

Out of 289 patients, 111 (38.4%) showed LGE and 83/111 (28.7% of the total population) showed a non-junctional distribution. During the follow-up (45±27 months), 10 patients needed ICD after malignant ventricular arrhythmias (7 patients with LGE, 3 patients without LGE). CMR predictors of cardiac events by univariate analysis were left and right ventricular ejection fractions, indexed right atrial area and non-junctional LGE. At multivariate analysis, macroscopic myocardial fibrosis detected by LGE was an independent predictor (hazard ratio 5.4; 95% C.I. 1.1–28.8, p&lt;0.05; see figure for Kaplan-Meier curves).

Conclusions

Presence of ventricular LGE at CMR may represent an independent predictor for further malignant ventricular arrhythmias requiring ICD implantation in SSc patients.

Kaplan-Meier curves

Funding Acknowledgement

Type of funding source: None

THU0355 PARAMETRIC CARDIAC MAGNETIC RESONANCE IMAGING IDENTIFIES ARRHYTHMOGENIC SUBSTRATES IN SYSTEMIC SCLEROSIS PATIENTS

Background:

Cardiac involvement in systemic sclerosis (SSc) accounts for 26-36% of deaths. This most frequently manifests as ventricular rhythm disturbances (VRDs), eventually culminating in sudden cardiac death. However, no specific guidelines exist for implantation of cardioverter defibrillators (ICD) in SSc patients. Parametric cardiovascular magnetic resonance (CMR) indices of myocardial oedema and fibrosis like native T1/T2 mapping have been shown to be associated with prognosis in SSc patients with acute cardiac events and normal echocardiograms. However, their relationship with arrhythmogenicity per se has not been previously investigated in SSc.

Objectives:

To investigate the relationship between parametric CMR indices and arrhythmogenicity in SSc patients.

Methods:

84 consecutive SSc patients (80% diffuse-cutaneous SSc) from eight European centers presenting with cardiac symptoms were examined using a 1.5 T CMR system. 24h Holter recordings were obtained within a month of the CMR scan. The presence of VRDs was defined as any type of premature ventricular contraction (PVC) in couples, triplets, bigeminism, trigeminism, quadrigeminism and non-sustained ventricular tachycardia, as well as having >30 PVCs per hour. Logistic regression analysis was used to evaluate the relationship between VRD occurrence and native T1/T2 mapping as well as myocardial extracellular volume fraction (ECV).

Results:

Mean age in the cohort was 55 (13) years and 78 (93%) patients were female. Of these, 67 (80%) experienced at least one type of VRDs. Each 10 ms increase of native T1-mapping was associated with a higher occurrence of VRDs [odds ratio (95% confidence interval): 1.21 (1.08-1.36), p=0.001]. Similarly, a 1% increase in ECV conferred an increased probability of experiencing VRDs [1.25 (1.01-1.53), p=0.037]. Lastly, a 1ms unit increase in T2-mapping also led to increased probability of having experienced VRDs [1.09 (1.01-1.19), p=0.035].

Conclusion:

Parametric CMR indices are associated with arrhythmogenicity in SSc patients with cardiac symptoms and should be investigated further in larger studies for their clinical utility in selecting high-risk SSc patients for ICD implantation.

Disclosure of Interests:

Sophie I. Mavrogeni: None declared, Luna Gargani: None declared, Alessia Pepe: None declared, Lorenzo Monti: None declared, George Markousis-Mavrogenis: None declared, Maria De Santis: None declared, Antonella Meloni: None declared, Loukia Koutsogeorgopoulou: None declared, Georgia Karabela: None declared, Efthymios Stavropoulos: None declared, Gkikas Katsifis Grant/research support from: UCB Pharma, Janssen, Abbvie, Novartis, MSD, Aenorasis, Genesis Pharma, Pfizer, Roche, Consultant of: UCB Pharma, Janssen, Abbvie, Novartis, MSD, Aenorasis, Genesis Pharma, Pfizer, Roche, Speakers bureau: UCB Pharma, Janssen, Abbvie, Novartis, MSD, Aenorasis, Genesis Pharma, Pfizer, Roche, Konstantinos Bratis: None declared, Silvia Bellando Randone: None declared, Serena Guiducci: None declared, Cosimo Bruni: None declared, Alberto Moggi-Pignone: None declared, Theodoros Dimitroulas: None declared, Paraskevi Voulgari: None declared, Genovefa Kolovou: None declared, Vasiliki-Kalliopi Bournia Grant/research support from: Travel Grant from Boehringer Ingelheim, Monica Mukherjee: None declared, Joao Lima: None declared, George D. Kitas: None declared, Petros Sfikakis Grant/research support from: Grant/research support from Abvie, Novartis, MSD, Actelion, Amgen, Pfizer, Janssen Pharmaceutical, UCB, Marco Matucci-Cerinic Grant/research support from: Actelion, MSD, Bristol-Myers Squibb, Speakers bureau: Acetelion, Lilly, Boehringer Ingelheim

109 Anderson Fabry disease in CMR: twins by traditional tissue characterization, different by parametric mapping

Conclusion

The case of this family show how quantitative parametric mapping could be a unique tool for the clinicians to adjust the therapy and plan the follow up of patients affected by AFD with cardiac involvement.

Abstract 109 Figure.

415 Comparison between two methods for assessing ventricular-arterial coupling: the Chen single-beat method and carotid artery wave intensity

Background

Ventricular arterial coupling (VAC) can be defined as the ratio of the arterial elastance (Ea) to the ventricular elastance (Ees). . The Ea/Ees ratio has been consistently demonstrated to be a reliable and effective measure of cardiovascular performance. The Chen single-beat method is the most used non-invasive method for this measurement. Carotid artery wave intensity (WI) is also considered a index of VAC, as the first peak (W1) represents the forward compression wave, reflecting left ventricle (LV) contractile function. However, data about the relationship between the two methods are nowadays scarce.

Purpose

Aim of the study was to compare carotid WI and Ventricular-Arterial Coupling (VAC) in a population of patient with heart failure.

Methods

We examined 50 consecutive patients with heart failure (9 females, 41 males, mean age 67 + 12 years, range 29-97 years, 34 ischemic, 16 not ischemic). Carotid artery wave intensity was achieved merging the echo-tracking of the vessel with its doppler signal. Simultaneous not-invasive oscillometric blood pressure was obtained. The VAC was assessed by the ratio between the arterial elastance (Ea) and the end-systolic ventricular elastance (Ees). Ea was calculated from stroke volume (SV) and end-systolic pressure (Ea=(Systolic BP x 0.9)/SV) and Ees was calculated by the modified single-beat Chen method, using an estimated normalized ventricular elastance at arterial end-diastole (ENd) Ees = [Diastolic BP-(ENd(est) x Systolic BP x 0.9)]/(ENd(est) x SV). Three subgroups were created according to the left ventricle ejection fraction values (LVEF ≤ 35%, LVEF &gt;35% &lt;50%, LVEF ≥ 50%, with 26, 14, 10 patients respectively).

Results

The correlation between Ea/Ees and W1 was significant (Pearson’s correlation r= -0.35, p 0.01). The W1 and VAC values of the three LVEF-sorted subgroups were processed with ANOVA test (p 0.054 and p 0.0002 respectively). W1 values resulted to be, as expected, reduced especially in the group of severe ventricular dysfunction (mean 4,97+- 3,29), as well as the ventricular-arterial coupling was increased (mean 2.04 +- 1.04). Interestingly W1 shows to be correlated with the Left atrial volume index (Pearson’s correlation r= -0,30 p = 0,037).

Conclusions

Carotid WI technique seems to be a reliable method to estimate the ventricular-arterial interplay. Larger studies are needed to evaluate the respective role of W1 and Ea/Ees in the prognostic evaluation.

Results EF ≤ 35 (n = 10) 35 &lt; EF &lt; 50 (n = 14) EF≥ 50 (n = 26) p value W1 4.97 ± 3.29 8.05 ± 3.79 7.85 ± 3.12 0.054 Ea/Ees 2.04 ± 1.04 1.39 ± 0.31 1.16 ± 0.3 0.0002

Abstract 415 Figure.

1177 The additive prognostic value of end-systolic pressure-volume relation by CMR in patients with with known or suspected coronary artery disease

Background

The variation between rest and peak stress end-systolic pressure-volume relation is an afterload-independent index of left ventricular contractility. This index is easily obtained during routine stress echocardiography but can be derived also during a stress cardiovascular magnetic resonance (CMR) exam, that is the gold standard for the quantification of biventricular volumes.

Purpose

The aim of this study was to assess for the first time the prognostic value ofdelta rest-stress ESPVR (DESPVR) by dipyridamole stress-CMR in patients with known or suspected coronary artery disease (CAD).

Methods

One hundred and sixty-six consecutive patients (37 females, main age 61.96 ± 10.05 years) who underwent dipyridamole stress-CMR in a high volume CMR Laboratory were considered. Abnormal wall motion and perfusion at rest and after dipyridamole were analysed. Macroscopic myocardial fibrosis was detected by the late gadolinium enhancement (LGE) technique. The ESPVR was evaluated at rest and peak stress from raw measurement of systolic arterial pressure by cuff sphygmomanometer and end-systolic volume by biplane Simpson method.

Results

An abnormal stress CMR was found in 39 (23.5%) patients; 24 patients had a reversible stress perfusion defect in at least one myocardial segment and 15 a reversible stress perfusion defect plus worsening of stress wall motion in comparison with rest. Myocardial fibrosis was detected in 69 patients (41.6%). A DESPVR &lt; 0.009 was detected in 74 patients (44.6%).

During a median follow up of 55.51 months (IQ range 33.20 months), 54 patients (32.5%) experienced major cardiac events: 5 deaths, 2 ventricular arrhythmias, 18 coronary syndromes, and 29 heart failure hospitalization.Reversible perfusion deficit, DESPVR &lt; 0.009, diabetes and family history were significant univariate prognosticators. In the multivariate analysisthe independent predictive factors were reversible perfusion deficit (hazard ratio-HR = 2.17, P = 0.010), DESPVR &lt; 0.009 (HR = 1.92, P = 0.028) and diabetes (HR = 2.42, P = 0.004). The Kaplan–Meier curve for DESPVR is shown in Figure 1. The log-rank test revealed a significant difference (P = 0.003).

Conclusions

DESPRV assessed by CMR provides a prognostic stratification in patients with known or suspected coronary artery disease, in addition to that supplied by reversible perfusion deficit and diabetes.

Abstract 1177 Figure 1

P1806 Relation between carotid artery wave intensity compression wave and left ventricular dp/dt

Background

Invasive catheter-based studies demonstrated a correlation between left ventricular (LV) dP/dt, a well known index of contractility, and carotid artery wave intensity compression wave.

It is possible to estimate LV dP/dt with ultrasound, evaluating the slope of continuous Doppler wave of mitral regurgitation in early systole. Wave intensity (WI) is achieved merging the echo-tracking of the common carotid artery with the simultaneous pulsed Doppler signal inside the vessel. The first peak (W1) represents the forward compression wave, reflecting theoretically LV contractile function. Nowadays data about the relationship between the two dP/dt methods are scarce.

Purpose

The aim of the study is to compare carotid artery WI and mitral regurgitation wave-derived LV dP/dt in a population of patients with ischemic and not ischemic heart failure.

Methods

We examined 31 consecutive patients with heart failure (7 females, 24 males, mean age 66.7 + 13.9 years, range 29-97 years, 21 ischemic, 10 not ischemic). All patients had at least a mild mitral regurgitation. Two subgroups were created according to the left ventricle ejection fraction values (LVEF ≤ 45% and LVEF &gt; 45%, with 15 and 16 patients respectively). A simultaneous not-invasive brachial blood pressure was obtained.

Results

The W1 was significantly linearly correlated with the echocardiographic LV dP/dt value (r = 0.41, p 0.02). Both W1 and LV dP/dt correlated significantly with LV ejection fraction.

Conclusions

Carotid WI evaluation, and specifically its first peak W1, could be reinterpreted as an alternative method to estimate not invasively LV contractility performance. Larger studies are needed to evaluate the relative prognostic role of carotid artery W1 and LV dP/dt in clinical practice.

Results LVEF ≤ 45 % (n = 15) LVEF &gt; 45 % (n = 16) p value W1 6.19 +- 3.77 9.3 +- 3.43 0.02 dP/dT 789 +- 329 1244 +- 337 0.0007

Abstract P1806 Figure. Common Carotid Artery eTracking

P1830 Single-beat aortic arch pulse wave velocity by dual-gate simultaneous Doppler technique: a novel method for arterial stiffness evaluation

Background

Guidelines recommend increased aortic stiffness as a negative prognostic factor to be considered in primary and secondary prevention. Pulse wave velocity (PWV) is a frequently employed surrogate marker of aortic stiffness. Carotid-femoral PWV is the most common index in research and clinical practice, but recently several velocity-encoded magnetic resonance imaging (MRI) techniques have been used for the evaluation of regional aortic arch PWV, where the stiffness seems to be particularly relevant from a prognostic point of view.

Purposes. We developed a new ultrasound method for the assessment of aortic arch PWV, using a single-beat dual-gate simultaneous pulsed wave Doppler tracing. The aim of the study is to evaluate the feasibility of this new technique in a group of healthy volunteers.

Methods

We examined 126 healthy volunteers (81 females, 45 males, mean age 42 + 15 years, range 13-83 years) using a commercially available machine equipped with simultaneous dual-gate pulsed Doppler. Using the suprasternal approach, the first sample volume was placed in ascending aorta and the second one in descending aorta. The distance between the two sites was directly measured with a curvilinear tracing in the middle of the vessel, following the shape of the aortic arch. PWV was calculated as the ratio of distance (in millimiters) and the transit time (in milliseconds) measured using the "foot-to-foot" method. The results are then easily transformed, simplifying in the commonly unit of meters/second.

Results

Feasibility was 99%; in one case it was not possible to measure accurately the aortic arch PWV due to unfavorable suprasternal acustic window. The procedure time was very fast, requiring 2 + 1 minutes. Intraobserver and interobserver variability were 7% and 9% respectively. Aortic arch PWV, as expected, showed a strong correlation with age in males as well as in females (r= 0.71 and r = 0.60 respectively, p &lt; 0.001 for both); there was also a significant correlation with body mass index (r = 0.31; p &lt; 0.001). Aortic arch PWV values ranged from 3.1 to 8.5 m/s, showing a substantial overlap with normal values reported in MRI studies.

Conclusions

The direct measurement of aortic arch PWV is feasible and reproducible with ultrasound, using the novel single-beat dual-gate simultaneous pulsed wave Doppler tracing. This technique could be implemented in a standard echo examination, that is much more available than MRI studies. Further studies are needed to evaluate if Doppler-derived aortic arch PWV could provide additional prognostic information.

Abstract P1830 Figure. Aortic Arch PWV

P5263Genotype and cardiac findings in non transfusion dependent thalassemia patients

Background

In non transfusion dependent thalassemia (NTDT) the lack of a clear genotype-phenotype relationship complicates the already complex and extensive scenario in clinical practice.

Purpose

Our aim was to detect if the presence of a β°/β° homozygous genotype was associated to different rate of cardiac findings by Cardiovascular Magnetic Resonance (CMR) and cardiac complications.

Methods

We considered 81 patients with thalassemia intermedia never transfused o who received occasional transfusions (37.7±11.4 years, 39 females) consecutively enrolled in the Myocardial Iron Overload in Thalassemia project. CMR was used to quantify iron overload (T2* technique), biventricular morphological and functional parameters (cine sequences), and the presence of myocardial fibrosis (late gadolinium enhancement-LGE technique). All cardiac complications were classified according to international guidelines.

Results

Two groups of patients were identified: non homozygous β°/β° genotype (N=61) and homozygous β°/β° genotype (N=20.) No significant differences for sex and age were found between the groups.

Patients with homozygous β°/β° genotype had lower mean haemoglobin levels (8.6±1.1g/dl vs 9.2±1.2 g/dl) but the difference did not reach the statistical significance (P=0.060).

No patient showed cardiac iron and global heart T2* values were comparable between the two groups. Left atrial area index, left ventricular (LV) end-diastolic, end-systolic and stroke volume indexes, LV mass index, right ventricular end-diastolic and end-systolic volume indexes were significantly higher in the homozygous β°/β° group (see Table).

Frequencies of heart failure and arrhythmias were comparable between the groups.

Non-β0/β0 homozygous genotype β0/β0 homozygous genotype P Left Atrial Area (cm2/m2) 13.87±2.59 16.63±2.59 0.001 LV EDVI (ml/m2) 94.88±15.59 112.94±21.52 0.003 LV ESVI (ml/m2) 35.22±9.55 41.88±9.70 0.018 LV SVI (ml/m2) 61.98±12.57 69.81±11.20 0.029 LV mass index (g/m2) 61.26±10.15 68.63±15.89 0.030 RV EDVI (ml/m2) 91.27±23.50 107.53±23.87 0.019 RV ESVI (ml/m2) 33.93±17.55 40.81±15.20 0.043

Conclusions

Heart remodelling related to a high cardiac output state cardiomyopathy was more pronounced in patients with homozygous β°/β° genotype. These data can support the knowledge of different phenotypic groups in the management of NTDT patients.

P5285Pressure-volume relationship by cardiovascular magnetic resonance: feasibility and clinical implications

Background

The variation between rest and peak stress end-systolic pressure-volume relation (ESPVR; the Suga index) is easily obtained during routine stress echocardiography and has been established as a reasonably load-independent index of myocardial contractile performance that provides prognostic information above and beyond regional wall motion.

Purpose

This is the first study assessing the delta rest-stress ESPVR (DESPVR) by stress Cardiovascular Magnetic Resonance (CMR).

Methods

Eighty-five consecutive patients (19 females, main age 62.99±9.26 years) who underwent dipyridamole stress-CMR in a high volume CMR Laboratory were considered. The ESPVR was evaluated at rest and peak stress from raw measurement of systolic arterial pressure by cuff sphygmomanometer and end-systolic volume by biplane Simpson method.

Results

Mean ESPVR index at rest and peak stress was, respectively, 4.52±2.26 mmHg/mL/m2 and 4.62±2.32 mmHg/mL/m2 and mean DESPVR was 0.11±1.19 mmHg/mL/m2.

DESPVR was not associated to age or sex.

An inverse relationship between rest left ventricular end-diastolic volume index (LVEDVI) and both rest and peak ESPVR was present (R=-0.805 P<0.0001 and R=-0.795 P<0.0001, respectively), but it was absent when the DESPVR was considered (R=0.170 P=0.121).

An abnormal stress CMR was found in 22 patients and the DESPVR was comparable between patients with normal and abnormal stress exam.

During a median follow-up of 60.62 months (IQ range 36.78 months), 27 cardiovascular events occurred: 3 deaths, 1 ventricular arrhythmias, 9 coronary syndromes, 14 heart failure hospitalization. At receiver-operating characteristic (ROC) curve analysis, a DESPVR<0.009 predicted the presence of future cardiac events with a sensitivity of 0.70 and a specificity of 0.64 (P=0.049).

Conclusions

We showed for the first time that dipyridamole stress CMR can be used for the assessment of DESPVR. DESPVR was shown to be independent from chamber size and, as a consequence, can be used for a comparative assessment of patients with different diseases. DESPVR by CMR can provide a prognostic stratification and the optimal cutoff for relevant events was 0.009.

P601Heart disease and pancreatic iron in thalassemia major

Background

Some preliminary data have postulated a correlation between pancreatic iron overload and heart iron and function in thalassemia major (TM) patients.

Purpose

In the present multicenter study we explored systematically the link between pancreatic iron and heart disease in a large cohort of TM patients.

Methods

We considered 880 TM patients (467 M, mean age 37.83±10.05 years) enrolled in the E-MIOT (Extension-Myocardial Iron Overload in Thalassemia) project. T2* measurements were performed over pancreatic head, body and tail and global value was the mean. Myocardial iron overload (MIO) was quantified using a T2* segmental approach. Biventricular function parameters were assessed by cine images. Late gadolinium enhancement (LGE) images were acquired to detect myocardial fibrosis.

Results

A significant correlation between pancreatic and cardiac iron was reconfirmed in this more numerous population and a normal pancreas T2* showed negative predictive value of 100% for cardiac iron.

LGE sequences were acquired in 273 TM patients and 84 (30.77%) of them showed macroscopic myocardial fibrosis. Global pancreas T2* values were significantly lower in patients with fibrosis (7.38±6.19 ms vs 11.91±9.79 ms; P<0.0001).

Sixty-four patients had at least one cardiac complication (arrhythmias, heart failure, pulmonary hyperthension, vascular disease). Patients with cardiac complications showed a significant lower global pancreas T2* (7.83±5.61 ms vs 12.76±10.34 ms; P=0.024). Specifically, global pancreas T2* values were significantly lower in patients with heart failure as well as in patients with arrhythmias and all patients with one of these two diseases had a pathologic global pancreas T2* value (see Figure).

Conclusion

Pancreatic iron is a strong predictor not only for cardiac iron, but also for cardiac complications supporting a more profound link between pancreatic iron and heart disease in TM.

Intracortical Myelination of Heschl's Gyrus and the Planum Temporale Varies With Heschl's Duplication Pattern and Rhyming Performance: An Investigation of 440 Healthy Volunteers

We investigated, in 445 healthy adults whose Heschl's gyrus (HG) gyrification patterns had been previously identified, how an in vivo MRI marker of intracortical myelination of HG and the planum temporale (PT) varied as a function of HG gyrification pattern and, in cases of duplication, of anatomical characteristics of the second HG (H2). By measuring the MRI T1/T2 ratio in regions of interest covering the first HG (H1), H2 in cases of common stem (H2CSD), or complete posterior duplication (H2CPD) and the PT, we showed that H1 had the highest T1/T2 values, while the PT had the lowest. The major impact of duplication was a decrease in both H1 and PT T1/T2 values in cases of left CPD. Concerning H2, the right and left T1/T2 values of right H2CSD were closer to those of H1, and those of left H2CPD were closer to those of PT. After adjusting for verbal skills, rhyming performance was not associated with T1/T2 values in left regions, but it decreased with increasing right PT T1/T2 values. These results reveal the existence of hemispheric differences in H2 myelination and underline the importance of neuroimaging markers of intracortical myelination for investigating brain structure-function relationships.

Controlled and tuneable drug release from electrospun fibers and a non-invasive approach for cytotoxicity testing

Electrospinning is an attractive method to generate drug releasing systems. In this work, we encapsulated the cell death-inducing drug Diclofenac (DCF) in an electrospun poly-L-lactide (PLA) scaffold. The scaffold offers a system for a sustained and controlled delivery of the cytotoxic DCF over time making it clinically favourable by achieving a prolonged therapeutic effect. We exposed human dermal fibroblasts (HDFs) to the drug-eluting scaffold and employed multiphoton microscopy and fluorescence lifetime imaging microscopy. These methods were suitable for non-invasive and marker-independent assessment of the cytotoxic effects. Released DCF induced changes in cell morphology and glycolytic activity. Furthermore, we showed that drug release can be influenced by adding dimethyl sulfoxide as a co-solvent for electrospinning. Interestingly, without affecting the drug diffusion mechanism, the resulting PLA scaffolds showed altered fibre morphology and enhanced initial DCF burst release. The here described model could represent an interesting way to control the diffusion of encapsulated bio-active molecules and test them using a marker-independent, non-invasive approach.

Tunable uptake/release mechanism of protein microgel particles in biomimicking environment

Microgels are intra-molecular crosslinked macromolecules that can be used as vehicles to deliver and release drugs at the point-of-need in the patient’s body. Here, gelatin microgels were formed from microfluidics droplets, stabilised by aldehydes and frozen into a spheroidal shape. Microgel morphology and response to external stimuli were characterised. It was found that the behaviour of the spheroidal microgels was sensitive to both pH and ionic strength and that the distribution of charges into the microgels affected the behaviour of swelling and uptake. The uptake of molecules such as Rhodamine B and Methylene Blue were investigated as a model for drug uptake/release mechanisms. Under physiological conditions, the uptake of Rhodamine was rapid and a uniform distribution of the fluorescent molecules was recorded inside the microgels. However, the mechanism of release became slower at lower pH, which mimics the stomach environment. Under physiological conditions, Methylene Blue release occurred faster than for Rhodamine. Anionic and neutral molecules were also tested. In conclusion, the dependence of uptake and release of model drugs on basic/acid conditions shows that microgels could be used for targeted drug delivery. Different shaped microgels, such as spheres, spheroids, and rods, could be useful in tissue engineering or during vascularisation.