[Precision medicine enhances personalized medicine in cardiology]

Personalized medicine and precision medicine, frequently used synonymously, shall be clearly differentiated. Accordingly, personalization in cardiac medicine is based on the clinical presentation of a patient, as well as his/her cardiovascular risk factors and comorbidities, electrocardiography, imaging, and biomarkers for myocardial load and ischemia. Personalization is based on large clinical trials with detailed subgroup analyses and is practiced on the basis of guidelines. Further in depth personalization is achieved by precision medicine, which is based on innovative imaging for myocardial structure, coronary morphology, and electrophysiology. From the clinical perspective, genome analyses are relevant for comparatively rare monogenetic cardiovascular diseases. While these as well as transcriptome and metabolome analyses play a significant role in cardiovascular research with great translation potential, they have not yet been broadly introduced in the diagnosis, prevention, and treatment of complex cardiovascular diseases. Furthermore, digital technologies have considerable potential in cardiovascular precision medicine. On the one hand, this is based on the frequency of the diseases with the availability of Big Data and, on the other hand, on the availability of bio-signals and sensors of those signals in cardiovascular diseases.

Effects of empagliflozin on progression of chronic kidney disease: a prespecified secondary analysis from the empa-kidney trial

BACKGROUND

Sodium-glucose co-transporter-2 (SGLT2) inhibitors reduce progression of chronic kidney disease and the risk of cardiovascular morbidity and mortality in a wide range of patients. However, their effects on kidney disease progression in some patients with chronic kidney disease are unclear because few clinical kidney outcomes occurred among such patients in the completed trials. In particular, some guidelines stratify their level of recommendation about who should be treated with SGLT2 inhibitors based on diabetes status and albuminuria. We aimed to assess the effects of empagliflozin on progression of chronic kidney disease both overall and among specific types of participants in the EMPA-KIDNEY trial.

METHODS

EMPA-KIDNEY, a randomised, controlled, phase 3 trial, was conducted at 241 centres in eight countries (Canada, China, Germany, Italy, Japan, Malaysia, the UK, and the USA), and included individuals aged 18 years or older with an estimated glomerular filtration rate (eGFR) of 20 to less than 45 mL/min per 1·73 m2, or with an eGFR of 45 to less than 90 mL/min per 1·73 m2 with a urinary albumin-to-creatinine ratio (uACR) of 200 mg/g or higher. We explored the effects of 10 mg oral empagliflozin once daily versus placebo on the annualised rate of change in estimated glomerular filtration rate (eGFR slope), a tertiary outcome. We studied the acute slope (from randomisation to 2 months) and chronic slope (from 2 months onwards) separately, using shared parameter models to estimate the latter. Analyses were done in all randomly assigned participants by intention to treat. EMPA-KIDNEY is registered at ClinicalTrials.gov, NCT03594110.

FINDINGS

Between May 15, 2019, and April 16, 2021, 6609 participants were randomly assigned and then followed up for a median of 2·0 years (IQR 1·5-2·4). Prespecified subgroups of eGFR included 2282 (34·5%) participants with an eGFR of less than 30 mL/min per 1·73 m2, 2928 (44·3%) with an eGFR of 30 to less than 45 mL/min per 1·73 m2, and 1399 (21·2%) with an eGFR 45 mL/min per 1·73 m2 or higher. Prespecified subgroups of uACR included 1328 (20·1%) with a uACR of less than 30 mg/g, 1864 (28·2%) with a uACR of 30 to 300 mg/g, and 3417 (51·7%) with a uACR of more than 300 mg/g. Overall, allocation to empagliflozin caused an acute 2·12 mL/min per 1·73 m2 (95% CI 1·83-2·41) reduction in eGFR, equivalent to a 6% (5-6) dip in the first 2 months. After this, it halved the chronic slope from -2·75 to -1·37 mL/min per 1·73 m2 per year (relative difference 50%, 95% CI 42-58). The absolute and relative benefits of empagliflozin on the magnitude of the chronic slope varied significantly depending on diabetes status and baseline levels of eGFR and uACR. In particular, the absolute difference in chronic slopes was lower in patients with lower baseline uACR, but because this group progressed more slowly than those with higher uACR, this translated to a larger relative difference in chronic slopes in this group (86% [36-136] reduction in the chronic slope among those with baseline uACR <30 mg/g compared with a 29% [19-38] reduction for those with baseline uACR ≥2000 mg/g; ptrend<0·0001).

INTERPRETATION

Empagliflozin slowed the rate of progression of chronic kidney disease among all types of participant in the EMPA-KIDNEY trial, including those with little albuminuria. Albuminuria alone should not be used to determine whether to treat with an SGLT2 inhibitor.

FUNDING

Boehringer Ingelheim and Eli Lilly.

Impact of primary kidney disease on the effects of empagliflozin in patients with chronic kidney disease: secondary analyses of the EMPA-KIDNEY trial

BACKGROUND

The EMPA-KIDNEY trial showed that empagliflozin reduced the risk of the primary composite outcome of kidney disease progression or cardiovascular death in patients with chronic kidney disease mainly through slowing progression. We aimed to assess how effects of empagliflozin might differ by primary kidney disease across its broad population.

METHODS

EMPA-KIDNEY, a randomised, controlled, phase 3 trial, was conducted at 241 centres in eight countries (Canada, China, Germany, Italy, Japan, Malaysia, the UK, and the USA). Patients were eligible if their estimated glomerular filtration rate (eGFR) was 20 to less than 45 mL/min per 1·73 m2, or 45 to less than 90 mL/min per 1·73 m2 with a urinary albumin-to-creatinine ratio (uACR) of 200 mg/g or higher at screening. They were randomly assigned (1:1) to 10 mg oral empagliflozin once daily or matching placebo. Effects on kidney disease progression (defined as a sustained ≥40% eGFR decline from randomisation, end-stage kidney disease, a sustained eGFR below 10 mL/min per 1·73 m2, or death from kidney failure) were assessed using prespecified Cox models, and eGFR slope analyses used shared parameter models. Subgroup comparisons were performed by including relevant interaction terms in models. EMPA-KIDNEY is registered with ClinicalTrials.gov, NCT03594110.

FINDINGS

Between May 15, 2019, and April 16, 2021, 6609 participants were randomly assigned and followed up for a median of 2·0 years (IQR 1·5-2·4). Prespecified subgroupings by primary kidney disease included 2057 (31·1%) participants with diabetic kidney disease, 1669 (25·3%) with glomerular disease, 1445 (21·9%) with hypertensive or renovascular disease, and 1438 (21·8%) with other or unknown causes. Kidney disease progression occurred in 384 (11·6%) of 3304 patients in the empagliflozin group and 504 (15·2%) of 3305 patients in the placebo group (hazard ratio 0·71 [95% CI 0·62-0·81]), with no evidence that the relative effect size varied significantly by primary kidney disease (pheterogeneity=0·62). The between-group difference in chronic eGFR slopes (ie, from 2 months to final follow-up) was 1·37 mL/min per 1·73 m2 per year (95% CI 1·16-1·59), representing a 50% (42-58) reduction in the rate of chronic eGFR decline. This relative effect of empagliflozin on chronic eGFR slope was similar in analyses by different primary kidney diseases, including in explorations by type of glomerular disease and diabetes (p values for heterogeneity all >0·1).

INTERPRETATION

In a broad range of patients with chronic kidney disease at risk of progression, including a wide range of non-diabetic causes of chronic kidney disease, empagliflozin reduced risk of kidney disease progression. Relative effect sizes were broadly similar irrespective of the cause of primary kidney disease, suggesting that SGLT2 inhibitors should be part of a standard of care to minimise risk of kidney failure in chronic kidney disease.

FUNDING

Boehringer Ingelheim, Eli Lilly, and UK Medical Research Council.

Unmasking systolic impairment in HFpEF by cardiovascular magnetic resonance derived hemodynamic force assessment: insights from the HFpEF stress trial

Background

The diagnosis of heart failure with preserved ejection fraction (HFpEF) remains challenging. Exercise-stress testing is recommended in case of uncertainty; however, this approach is time-consuming and costly. Since preserved EF does not represent normal systolic function, we evaluated cardiovascular magnetic resonance (CMR) comprehensive cardiac hemodynamic forces (HDF) analyses for an in-depth characterisation of cardiac function at rest.

Methods

The HFpEF Stress Trial (DZHK-17) prospectively recruited 75 patients with exertional dyspnea, preserved EF (≥50%) and signs of diastolic dysfunction (E/e' ≥8) on echocardiography. Patients underwent right heart catheterisation, echocardiography and CMR. 68 patients entered the final study cohort (HFpEF n=34 and non-cardiac dyspnea n=34 according to pulmonary capillary wedge pressure (PCWP)). HDF assessment included left ventricular (LV) longitudinal, systolic peak and impulse, systolic/diastolic transition, E-wave deceleration as well as A-wave acceleration forces. Two patients were lost to 24 months follow-up evaluating cardiovascular mortality and hospitalisation (CVH).

Results

HDF assessment revealed impairment of LV longitudinal force in HFpEF (15.8 vs. 18.3, p=0.035) attributable to impairment of systolic peak (38.6 vs 51.6, p=0.003) and impulse (20.8 vs. 24.5, p=0.009) forces as well as late diastolic filling (−3.8 vs −5.4, p=0.029). Impairment of early diastolic filling could be observed in HFpEF patients identified at rest only but not stress (7.7 vs. 9.9, p=0.004). Impaired systolic peak was associated to CVH (HR 0.95, p=0.016) and superior for CVH prediction compared to LV global longitudinal strain (AUC 0.76 vs. 0.61, p=0.048).

Conclusions

Assessment of HDF reveals impairment of LV systolic and diastolic function in HFpEF. The value of systolic HDF assessment exceeded that of conventional deformation imaging for CVH prediction.

Funding Acknowledgement

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): German Centre for Cardiovascular Research

Comparison of different sowtware solutions for AVC quantification using contrast enhanced MDCT

Funding Acknowledgements

Type of funding sources: None.

Aims

Estimating aortic valve calcification (AVC) derived from multi detector computed tomography (MDCT) scans in aortic stenosis (AS) patients has gained increasing interest for diagnostic and prognostic reasons. Little is known about the interchangeability of AVC obtained from different software solutions which, was systematically determined in consecutive patients undergoing contrast enhanced MDCT before TAVR.

Methods and results

50 randomly selected patients who underwent contrast enhanced MDCT for TAVR planning were included in the analysis. All MDCT data sets were analysed using three different software vendors (3 Mensio, CVI 42, Snygo.Via). AVC score was expressed as mm³. For analysing intra- and inter-observer variability a subset of 10 patients were analysed twice with at least 2 weeks in between the measurements. Intra- and inter-observer variability was quantified using the ICC reliability method, Bland-Altman analysis and coefficients of variation.

AVC scores were successfully obtained using all software solutions (3 Mensio 941 ± 623, CVI42 941 ± 637, Syngo.Via 948 mm³ ± 655) without significant differences (p = 0.455). There was excellent intra- (3 Mensio: ICC 0.999 [0.995 – 1.000], COV 3.86 %, mean difference -19.28 [± 45.07]; CVI 42: ICC 1.000 [0.999 – 1.000], COV 1.6 %, mean difference -10.28 [± 18.6]; Syngo.Via: ICC 0.998 [0.993 – 1.000], COV 4.13 %, mean difference -24.81 [± 48.52]) and inter-observer variability (3 Mensio: ICC 1.000 [0.999 – 1.000], COV 1.38 %, mean difference -7.14 [± 16.20]; CVI 42: ICC 1.000 [1.000 – 1.000], COV 1.01 %, mean difference -1.74 [± 11.83]; Syngo.Via: ICC 0.996 [0.985 – 0.999], COV 6.68 %, mean difference -0.65 [± 79.43]) for all software types. Best inter-vendor agreement was found between CVI 42 and Syngo.Via (ICC 0.997 [CI 0.995-0.998], COV 7.26 %, mean difference -7 [± 68.60]) followed by 3 Mensio / CVI 42 (ICC 0,996 [CI 0,922-0,998], COV 8.95 %, mean difference -0.06 [± 84.16]) and 3 Mensio / Syngo.Via (ICC 0,992 [CI 0,986-0,995], COV 12.19%, mean difference -7.06 [± 115.07]).

Conclusion

Contrast enhanced MDCT derived AVC scores are interchangeable between and reproducible within different commercially available software solutions. This is important since sufficient reproducibility, inter-changeability and valid results represent prerequisites for accurate TAVR planning and wide spread clinical use.

Aortic valve calcification and endomyocardial fibrosis determine adverse outcomes following transcatheter aortic valve replacement

Funding Acknowledgements

Type of funding sources: None.

Aims

There is evidence to suggest that subtype of aortic stenosis (AS), degree of myocardial fibrosis (MF) and level of aortic valve calcification (AVC) are associated with adverse cardiac outcome in AS. Since little is known about their respective contribution, we sought to investigate their relative importance and interplay as well as association with adverse cardiac events.

Methods

100 consecutive patients with severe AS and indication for transfemoral transcatheter aortic valve replacement (TAVR) were prospectively enrolled between January 2017 and October 2018. Patients underwent transthoracic echocardiography, multi detector computed tomography (MDCT) and left ventricular endomyocardial biopsy at the time of TAVR.

Results

The final study cohort consisted of 92 patients with completed study protocol comprising of 39 (42.4 %) normal ejection fraction high gradient (NEFHG), 13 (14.1 %) low EF high gradient (LEFHG), 25 (27.2 %) low EF (flow) low gradient (LEFLG) and 15 (16.3 %) paradoxical low flow low gradient (PLFLG) AS. The high gradient phenotypes (NEFHG and LEFHG) showed the largest amount of AVC (807 ± 421; 813 ± 281 mm³ respectively) as compared to the low gradient phenotypes (LEFLG and PLFLG; 503 ± 326; 555 ± 594 mm³ respectively, p &lt; 0.05). Conversely, MF was most prevalent in low output phenotypes (LEFLG &gt; LEFHG &gt; PLFLG &gt; HEFHG, p &lt; 0.05). This was paralleled by larger cardiovascular mortality within 600 days post TAVR (LEFLG n = 7 &gt; PLFLG n = 4 &gt; LEFHG n = 2 &gt; NEFHG n = 1). In Patients with high MF burden a higher AVC was associated with a lower mortality (p = 0.045, HR = 0.261, 95%CI 0.07-0.97). Within LEFLG AS, patients with larger AVC (&gt;476.8 mm³) had larger MF (40.2%) and higher cardiovascular mortality (n = 5) as compared to patients with lower AVC (£476.8 mm³, 17.1% MF, p = 0.027, cardiovascular mortality n = 2).

Conclusion

MF is associated with adverse cardiovascular outcome following TAVR which is most prevalent in low ejection fraction situations. In the presence of large MF burden patients with large AVC have better outcome following TAVR. Conversely worse outcome in large MF and relatively little AVC may be explained by a relative prominence of an underlying cardiomyopathy while better survival rates in large AVC patients may indicate severe AS associated pressure overload relief and subsequently improved survival following TAVR.

[Guideline for the Diagnosis and Treatment of Asthma - Addendum 2020 - Guideline of the German Respiratory Society and the German Atemwegsliga in Cooperation with the Paediatric Respiratory Society and the Austrian Society of Pneumology]

The present addendum of the guideline for the diagnosis and treatment of asthma (2017) complements new insights into the diagnosis and management of asthma as well as for the newly approved drugs for the treatment of asthma. Current, evidence-based recommendations on diagnostic and therapeutic approaches are presented for children and adolescents as well as for adults with asthma.

Cardiovascular magnetic resonance deformation imaging: method comparison and considerations regarding reproducibility

Funding Acknowledgements

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): German Centre for Cardiovascular Research

Purpose

Myocardial Feature-Tracking (FT) deformation imaging is superior for risk-stratification compared to volumetric approaches. Since there is no clear recommendation regarding FT post-processing, we compared different FT-strain analyses with reference standard techniques, including tagging and strain encoded (SENC) magnetic resonance imaging.

Methods

FT software from 4 different vendors (TomTec/Medis/Circle(CVI)/Neosoft), tagging (Segment), and fastSENC (MyoStrain) were used to determine left ventricular global circumferential and longitudinal strains (GCS/GLS) in 12 healthy volunteers and 12 heart failure patients. Variability and agreements were assessed using intraclass correlation coefficients for absolute agreement (ICCa) and consistency (ICCc) as well as pearson correlation coefficients.

Results

For FT-GCS, consistency was excellent comparing different FT-vendors (ICCc = 0.84-0.97, r = 0.86-0.95) and compared to fSENC (ICCc = 0.78-0.89, r = 0.73-0.81). FT-GCS consistency was excellent compared to tagging (ICCc = 0.79-0.85, r = 0.74-0.77) except for TomTec (ICCc = 0.68, r = 0.72). Absolute FT-GCS agreements between FT-vendors were highest for CVI and Medis (ICCa = 0.96) and lowest for TomTec and Neosoft (ICCa = 0.32). Similarly, absolute FT-GCS agreements were excellent for CVI and Medis compared to both tagging and fSENC (ICCa = 0.84-0.88), good to excellent for Neosoft (ICCa = 0.77 and 0.64) and lowest for TomTec (ICCa = 0.41 and 0.47).

For FT-GLS, consistency was excellent (ICCc≥0.86, r≥0.76). Absolute agreements between FT-vendors were excellent (ICCa = 0.91-0.93) or good to excellent for TomTec (ICCa = 0.69-0.85). Absolute agreements (ICCa) were good (CVI 0.70, Medis 0.60) and fair (TomTec 0.41, Neosoft 0.59) compared to tagging but excellent compared to fSENC (ICCa = 0.77-0.90).

Conclusion

Although absolute agreements differ depending on deformation assessment approaches, consistency and correlation are consistently high irrespective of the method chosen, thus indicating reliable strain assessment. Further standardisation and introduction of uniform references is warranted for routine clinical implementation.

Fully automated artificial intelligence-based myocardial scar quantification for diagnostic and prognostic stratification in patients following acute myocardial infarction

Funding Acknowledgements

Type of funding sources: None.

Background Myocardial infarct size (IS) remains one of the strongest predictors of adverse cardiac events following acute myocardial infarction (AMI). Late gadolinium enhancement (LGE) cardiac magnetic resonance (CMR) can precisely quantify the extent of injury but requires manual post-processing. Whether novel user-independent artificial intelligence (AI) based fully-automated analyses may facilitate clinical workflow and deliver similar information for risk stratification is unknown.

Methods 913 AMI patients from two multi-center trials (AIDA-STEMI n = 704 with ST-elevation myocardial infarction [STEMI] and TATORT-NSTEMI n = 245 with non-ST-elevation-infarction [NSTEMI]) were included in this sub-study. IS was quantified manually using conventional software (Medis, Leiden Netherlands) and fully automated AI-based software (NeoSoft). All automatically detected IS were evaluated visually and corrected if necessary. Analyzed data were tested for agreement and prediction of major adverse clinical events (MACE) within one year after AMI.

Results Automated and manual IS were similarly associated with outcome in cox regression analyses (HR 1.05 [95% CI 1-02-1.07] p &lt; 0.001 for automated IS and HR 1.04 [95% CI 1.02-1.06]; p &lt; 0.001 for manual IS). Comparison of C-statistics derived area under the curve (AUC) resulted in equivalent MACE prediction (AUC 0.65 for automated vs. AUC 0.66 for manual, p = 0.53). Manual correction of the automated scar detection did not lead to an improved risk prediction of MACE (AUC 0.65 to 0.66, p = 0.43). There was good agreement of automated and manually derived IS (intraclass correlation coefficient [ICC] 0.75 [0.07-0.89]) which was further improved after manual correction of the underlying contours (ICC 0.98 [0.97-0.98]).

Conclusion AI-based software enables automated scar quantification with similar prognostic value compared to conventional methods in patients following AMI.

Fully automated cardiac assessment for diagnostic and prognostic stratification following myocardial infarction

Funding Acknowledgements

Type of funding sources: None.

Background

Cardiovascular magnetic resonance (CMR) imaging is considered the reference methodology for cardiac morphology and function but requires manual post-processing. Whether novel artificial intelligence (AI) -based automated analyses deliver similar information for risk stratification is unknown. Therefore, this study aimed to investigate feasibility and prognostic implications of AI-based analyses.

Methods

CMR data (n = 1017 patients) from two myocardial infarction multi-center trials were included. Analyses of biventricular parameters including ejection fraction (EF) were manually and automatically assessed using conventional and AI-based software. Obtained parameters entered regression analyses for prediction of major adverse clinical events (MACE) defined as death, reinfarction or congestive heart failure within one-year after the acute event.

Results

Both manual and uncorrected automated volumetric assessments showed similar impact on outcome on univariate (LVEF HR 0.93, [95% CI 0.91-0.95]; p &lt; 0.001 for manual and HR 0.94 [0.92-0.96]; p &lt; 0.001 for automated) and multivariable analyses (LVEF HR 0.95, [0.92-0.98]; p = 0.001 for manual and HR 0.95 [CI 0.92-0.98]; p = 0.001 for automated). Manual correction of the automated contours did not lead to improved risk prediction (LVEF AUC 0.67 automated vs. 0.68 automated corrected, p = 0.49). There was acceptable agreement (bias: 2.6%, 95% limits of agreement [LOA] -9.1-14.2%, intraclass correlation coefficient [ICC] 0.88 [0.77-0.93] for LVEF) of manual and automated volumetric assessments.

Conclusions

User independent volumetric analyses performed by fully automated software are feasible and results are equally predictive of MACE compared with conventional analyses in patients following myocardial infarction.

CMR feature tracking remote myocardial strain analyses for optimized risk prediction following acute myocardial infarction

Funding Acknowledgements

Type of funding sources: None.

Background

Cardiac magnetic resonance myocardial feature tracking (CMR-FT) derived global strain assessments provide incremental prognostic information in patients following acute myocardial infarction (AMI). Functional analyses of the remote myocardium (RM) are scarce and whether they provide an additional prognostic value in these patients is unknown.

Methods

1052 patients following acute myocardial infarction were included. CMR imaging and strain analyses as well as scar size quantification were performed after reperfusion by primary percutaneous coronary intervention. The occurrence of major adverse cardiac events (MACE) within 12 months after the index event was defined as primary clinical endpoint.

Results

Patients with MACE had significantly lower RM circumferential strain (CS) compared to those without MACE. A cut-off value for RM CS of -25.8% best identified high-risk patients (p &lt; 0.001 on log-rank testing) and impaired RM CS was a strong predictor of MACE (HR 1.05, 95% CI 1.07-1.14, p = 0.003). RM CS provided further risk stratification amongst patients considered at risk according to established CMR parameters for 1.) patients with reduced left ventricular ejection fraction (LVEF) ≤ 35 % (p = 0.002 on log-rank testing), 2.) patients with reduced global circumferential strain (GCS) &gt; -18,3 % (p = 0.015 on log-rank testing), and 3.) patients with large microvascular obstruction ≥ 1.46 % (p = 0.038 on log-rank testing).

Conclusion

CMR-FT derived RM CS is a useful parameter to characterize the response of RM and allows improved stratification following AMI beyond commonly used parameters, especially of high-risk patients.

Twelfth European Students’ Conference

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Fourteenth European Students Conference

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Real-time cardiac magnetic resonance tissue characterisation for fibrosis assessment in aortic stenosis

Background

Myocardial fibrosis is a major determinant of outcome in aortic stenosis (AS). Novel fast real-time (RT) cardiac magnetic resonance (CMR) mapping techniques allow comprehensive quantification of fibrosis but have not yet been adequately validated against standard techniques and histology.

Methods

Patients with severe AS underwent CMR before (n=110) and left ventricular (LV) endomyocardial biopsy (n=46) at transcatheter aortic valve replacement (TAVR). Midventricular short axis native, post-contrast T1 and extracellular volume fraction (ECV) maps were generated using commercially available 5(3)3 MOLLI and RT single-shot inversion recovery fast low-angle shot (FLASH) with radial undersampling. ECV and LV mass were used to calculate LV matrix volumes. Variability and agreements were assessed between RT, MOLLI and histology using intraclass correlation coefficients, coefficients of variation and Bland Altman analyses.

Results

RT and MOLLI derived ECV were similar for myocardium (26.2 vs. 26.5, p=0.073) and inter-ventricular septum (26.2 vs. 26.5, p=0.216). MOLLI native T1 time was in median 20 ms longer compared to RT (p&lt;0.001). Agreement between RT and MOLLI was best for ECV (ICC &gt;0.91), excellent for post-contrast T1 times (ICC &gt;0.81) and good for native T1 times (ICC &gt;0.62). Diffuse collagen volume fraction by biopsies was in median 7.8%. ECV (RT r=0.345, p=0.039; MOLLI r=0.40, p=0.010) and LV matrix volumes (RT r=0.45, p=0.005; MOLLI r=0.43, p=0.007) were the only parameters associated with histology.

Conclusions

RT mapping offers precise T1 and ECV assessments with similar agreement with histology as compared to conventional MOLLI techniques. Single-shot real time techniques may be advantageous in sicker patients prone to dyspnoea or arrhythmia.

Funding Acknowledgement

Type of funding source: Foundation. Main funding source(s): German Research Foundation

Structural and functional reverse myocardial remodeling following transcatheter aortic valve replacement

Background

Myocardial reverse remodeling determines outcome in patients with severe aortic stenosis (AS) following transcatheter aortic valve replacement (TAVR). However, little is known about the interplay of myocardial function and structure after TAVR. Since cardiac magnetic resonance (CMR) imaging allows comprehensive quantification of both structure and function we aimed to assess changes in myocardial tissue composition and deformation before and following TAVR.

Methods

CMR imaging was performed in 40 prospectively enrolled patients with severe AS before and one year after TAVR. Myocardial function was characterized using volumetry and CMR-feature-tracking (FT) deformation imaging of left ventricular (LV) global longitudinal strain (GLS) and atrial function (atrial reservoir ES, conduit Ee and booster pump strain EA). Myocardial structure was assessed using T1 mapping and late gadolinium enhancement (LGE) analysis. LV cellular and matrix volumes were calculated based on extra cellular volume fraction (ECV) and LV mass. CMR-FT results were compared to a control group of twenty patients with normal biventricular function. Moreover, biomarkers (NT-proBNP), functional (six-minute-walking-test) and clinical status (NYHA, Minnesota LIVING WITH HEART FAILURE score) were determined at baseline and one-year follow-up.

Results

Regression of both cellular (−20.6%, p&lt;0.001) and matrix volumes (−12.3%, p=0.003) and subsequently increased ECV (+9.0%, p=0.001) were documented one year after TAVR. Ventricular and atrial strains were impaired at baseline (GLS p=0.004, Es p&lt;0.001, Ee p&lt;0.001) and recovered during follow-up (GLS p&lt;0.001, Es p=0.005, Ee p=0.001). These changes were paralleled by improvements in NYHA (p&lt;0.001) and Minnesota (p&lt;0.001) scores as well as decline in NT-proBNP levels (p=0.001). There was a significant association of LV fibrosis as defined by matrix volume and extent of LGE and ventricular and atrial functional impairment (correlation of matrix volume and: GLS r=0.57, p&lt;0.001, Es r=−0.44, p=0.009; correlation of LGE%LV and: GLS r=0.41, p=0.015, Es: r=−0.4, p=0.02, and Ea: r=−0.41, p=0.02).

Conclusion

Regression of fibrosis and cellular hypertrophy determine improved myocardial function and recovery from heart failure following TAVR. Prognostic implications of the observed changes will need to be explored next to identify makers and therapeutic targets for optimized management of these patients.

Funding Acknowledgement

Type of funding source: Foundation. Main funding source(s): German Research Foundation (DFG, CRC 1002, D1)

Performance of different myocardial tissue tracking algorithms and acquisition-based strain imaging to characterise myocardial pathology

Background

Myocardial deformation imaging is superior in risk-stratification compared to volumetric approaches. Myocardial Feature-Tracking (FT) allows easy post-processing of routinely acquired cine images. Since there is no clear recommendation regarding FT post-processing we sought to compare different FT-strains with reference standard techniques including tagging and strain encoded (SENC) magnetic resonance imaging.

Methods

CMR-FT software from 4 different vendors (TomTec, Medis, Circle, Neosoft), CMR tagging (Segment) and fastSENC (MyoStrain) were used to determine left ventricular (LV) global longitudinal and circumferential strains (GLS and GCS) in 12 healthy volunteers and 12 heart failure patients. Variability and agreements were assessed using intraclass correlation coefficients, coefficients of variation and Bland Altman plots.

Results

Compared to tagging, FT-based strain was software independently significantly higher except for GCS using Medis (p=0.178). Compared to fSENC, mean-differences of GLS were smaller within a range of ±1.5%. For GCS this only applied to CVI and Medis (&lt;1.5%) but not TomTec (&gt;7%) or Neosoft (&gt;4%). Absolute agreements comparing FT to tagging were best for CVI (GLS ICC0.70) and Medis (GCS ICC0.85). Compared to fSENC agreement of GLS was generally excellent (ICC&gt;0.77), but only CVI and Medis revealed excellent agreement for GCS (ICC0.88 and 0.85). Consistency and correlation of GLS were software independently high compared with tagging and fSENC (ICC&gt;0.86, r&gt;0.76) while being lower for GCS (ICC&gt;0.68, r&gt;0.72).

Conclusion

Although agreement differs between deformation assessment approaches, consistency and correlation are high irrespective of the method chosen, thus indicating reliable strain assessment. Further standardisation and introduction of uniform references is warranted for clinical routine implementation.

Funding Acknowledgement

Type of funding source: Public grant(s) – National budget only. Main funding source(s): DZHK - German Centre for Cardiovascular Research

Frequency and prognostic impact of right ventricular involvement in acute myocardial infarction

Background

Right ventricular (RV) involvement complicating myocardial infarction (MI) is thought to impact prognosis, but potent RV markers for risk stratification are lacking.

Purpose

To assess the frequency and prognostic implications of concomitant structural and functional RV injury in MI.

Methods

Cardiac magnetic resonance (CMR) was performed in 1235 patients with MI (STEMI: n=795; NSTEMI: n=440) 3 days after reperfusion by primary percutaneous coronary intervention. Central core laboratory-masked analyses included structural (edema representing reversible ischemia, irreversible infarction, microvascular obstruction [MVO]) and functional (ejection fraction, global longitudinal strain [GLS]) RV alterations. The clinical endpoint was the 12-month rate of major adverse cardiac events (MACE).

Results

RV ischemia and infarction were observed in 19.6% and 12.1% of patients, respectively, suggesting complete myocardial salvage in one-third of patients. RV ischemia was associated with a significantly increased risk of MACE (10.1% versus 6.2%; p=0.035), while patients with RV infarction showed only numerically increased event rates (p=0.075). RV MVO was observed in 2.4% and not linked to outcome (p=0.894). Stratification according to median RV GLS (10.2% versus 3.8%; p&lt;0.001) but not RV ejection fraction (p=0.175) resulted in elevated MACE rates. Multivariable analysis including clinical and left ventricular MI characteristics identified RV GLS as an independent predictor of outcome (hazard ratio 1.05, 95% confidence interval 1.00–1.09; p=0.034) in addition to age (p=0.001), Killip class (p=0.020), and left ventricular GLS (p=0.001), while RV ischemia was not independently associated with outcome.

Conclusions

RV GLS is a predictor of post-infarction adverse events over and above established risk factors, while structural RV involvement was not independently associated with outcome.

Funding Acknowledgement

Type of funding source: None

Differences in right ventricular-pulmonary vascular coupling and clinical indices between repaired standard tetralogy of Fallot and repaired tetralogy of Fallot with pulmonary atresia

PURPOSE

The purpose of this study was to compare ventricular vascular coupling ratio (VVCR) between patients with repaired standard tetralogy of Fallot (TOF) and those with repaired TOF-pulmonary atresia (TOF-PA) using cardiovascular magnetic resonance (CMR).

MATERIALS AND METHODS

Patients with repaired TOF aged>6 years were prospectively enrolled for same day CMR, echocardiography, and exercise stress test following a standardized protocol. Sanz's method was used to calculate VVCR as right ventricle (RV) end-systolic volume/pulmonary artery stroke volume. Regression analysis was used to examine associations with exercise test parameters, New York Heart Association (NYHA) class, RV size and biventricular systolic function.

RESULTS

A total of 248 subjects were included; of these 222 had repaired TOF (group I, 129 males; mean age, 15.9±4.7 [SD] years [range: 8-29 years]) and 26 had repaired TOF-PA (group II, 14 males; mean age, 17.0±6.3 [SD] years [range: 8-29 years]). Mean VVCR for all subjects was 1.54±0.64 [SD] (range: 0.43-3.80). Mean VVCR was significantly greater in the TOF-PA group (1.81±0.75 [SD]; range: 0.78-3.20) than in the standard TOF group (1.51±0.72 [SD]; range: 0.43-3.80) (P=0.03). VVCR was greater in the 68 NYHA class II subjects (1.79±0.66 [SD]; range: 0.75-3.26) compared to the 179 NYHA class I subjects (1.46±0.61 [SD]; range: 0.43-3.80) (P<0.001).

CONCLUSION

Non-invasive determination of VVCR using CMR is feasible in children and adolescents. VVCR showed association with NYHA class, and was worse in subjects with repaired TOF-PA compared to those with repaired standard TOF. VVCR shows promise as an indicator of pulmonary artery compliance and cardiovascular performance in this cohort.

564 Cardiac magnetic resonance myocardial feature tracking for optimized risk assessment after acute myocardial infarction in patients with type 2 diabetes

Objective

Type 2 diabetes mellitus (T2DM) associates with worse cardiovascular outcome following acute myocardial infarction (AMI) as compared to non-diabetic patients. Since the mechanisms behind these observations are not fully understood we aimed to quantify the underlying pathophysiology on ventricular and atrial levels and study their prognostic implications using cardiovascular magnetic resonance (CMR) quantitative feature-tracking (FT) and tissue characterization.

Research Design and Methods:

A total of 1147 consecutive patients with AMI (n = 265 with diabetes; n = 882 without diabetes) undergoing cardiac magnetic resonance (CMR) imaging in median 3 days after AMI were included in this multicenter study. Left ventricular (LV) function and volumetry included LV ejection fraction (LV-EF), global longitudinal (GLS), radial (GRS) and circumferential strain (GCS) as well as left atrial (LA) strain and strain rate parameters of LA reservoir, conduit and booster pump function. LV damage assessment included infarct size (IS), edema and microvascular obstruction (MO). The clinical study endpoint was the rate of major adverse cardiovascular events (MACE) at 12 months.

Results

T2DM patients had impaired LA reservoir (19.8 vs. 21.2%, p &lt; 0.01) and conduit strains 7.6 vs. 9.0%, p &lt; 0.01) but no differences in ventricular function or myocardial damage. They were at higher risk of MACE than non-diabetic patients (10.2% vs. 5.8%, p &lt; 0.01) with the majority of MACE occurring in patients with LVEF ≥ 35%. Whilst LVEF was an independent predictor of adverse events in non-diabetic patients (p = 0.04 on multivariable analysis), LV GLS as well as LA strain emerged as independent predictors of poor prognosis in patients with diabetes (p &lt; 0.02 on multivariable analysis). Considering patients with diabetes and LVEF ≥35% (n = 237), GLS and LA reservoir strain below median were significantly associated with higher 12-month event rates.

Conclusions

In patients with diabetes, LA and LV longitudinal strain permit optimized risk assessment early after reperfused AMI with incremental prognostic value over and above LVEF.

565 Impact of right atrial physiology on heart failure and adverse events after myocardial infarction

Background

Right ventricular (RV) function is a known predictor of adverse events in heart failure and following acute myocardial infarction (AMI). While right atrial (RA) involvement is well characterized in pulmonary arterial hypertension, its relative contributions to adverse events following AMI especially in patients with heart failure and congestion needs further evaluation.

Methods

1235 MI patients underwent CMR after primary percutaneous coronary intervention (PCI) in 15 centers across Germany (n = 795 with ST-elevation MI and 440 with non ST-elevation MI). Right atrial (RA) performance was evaluated using cardiac magnetic resonance myocardial feature tracking (CMR-FT) for the assessment of RA reservoir (total strain εs), conduit (passive strain εe), booster pump function (active strain εa) and associated strain rates (SR) in a blinded core-laboratory. The primary clinical endpoint was the occurrence of major adverse cardiac events (MACE) 12 months post MI.

Results

RA reservoir (εs p = 0.061, SRs p = 0.049) and conduit functions (εe p = 0.006, SRe p = 0.030) were impaired in patients with MACE as opposed to RA booster pump (εa p = 0.579, SRa p = 0.118) and RA volume index (p = 0.866). RA conduit function was associated with clinical onset of heart failure and MACE independently of RV systolic function (multi-variable analysis HR 0.95, 95% CI 0.91-0.99, p = 0.006) while RV systolic function was no independent prognosticator (HR 0.98, 95% CI 0.96-1.00, p = 0.055). Furthermore, RA conduit strain identified low- and high-risk groups within patients with relatively preserved and reduced RV and LV systolic functions (p &lt; 0.019 on log rank testing).

Conclusions

Right atrial impairment is a distinct feature and independent risk factor in patients following AMI and can be easily assessed using CMR-FT derived quantification of RA strain.

P1838 Defining the Optimal Temporal and Spatial Resolution for Cardiovascular Magnetic Resonance Imaging Feature Tracking

Background

Myocardial deformation analyses using cardiovascular magnetic resonance feature tracking (CMR-FT) have incremental value in the assessment of cardiac function beyond volumetric analyses. Since guidelines do not recommend specific imaging parameters, we aimed to define optimal spatial and temporal resolutions for CMR cine images to enable reliable post-processing.

Methods

Intra- and inter-observer reproducibility was assessed in 12 healthy volunteers. Cine images were acquired with differing temporal (20, 30, 40 and 50 frames/cardiac cycle) and spatial resolutions (high in-plane 1.5x1.5mm through-plane 5mm, standard 1.8x1.8x8mm and low 3.0x3.0x10mm). CMR-FT analyses comprised left ventricular (LV) global longitudinal strain (GLS) and systolic strain rate (SRs) as well as LV circumferential and radial strains (GCS and GRS) and right ventricular (RV) GLS. Intra- and inter-observer reproducibility was assessed in all subjects.

Results

Temporal but not spatial resolution did impact absolute strain and SR. Maximum absolute changes between lowest and highest temporal resolution were as follows: 2.3% LV GLS, 2.2%

GCS, 7.2% GRS, 1.7% RV GLS and 0.32s-1 SRs. Changes of time-integrated (strain) values occurred predominantly comparing 20 and 30 frames/cardiac cycle including LV GLS, GCS and GRS (p = 0.034, p = 0.008 and p = 0.034) in highest spatial resolution settings. In contrast, time-derivatives values (SRs) changed significantly from lower temporal resolutions to 40 frames/cardiac cycle and beyond (20 to 30 p = 0.002; 30 to 40 p = 0.018; 40 to 50 frames/cardiac cycle p = 0.075) in highest spatial resolution settings. Strain reproducibility was not affected by either temporal or spatial resolution. SRs variability as assessed by coefficient of variation decreased with higher temporal resolutions.

Conclusion

Temporal but not spatial resolutions significantly affect strain and SR in CMR-FT deformation analyses. Clinical CMR-FT strain and SR analyses require minimum temporal resolutions of 30 and 40frames/cardiac cycle, respectively to ensure precise quantification of myocardial function.

Inflammatory response to magnesium-based biodegradable implant materials

Biodegradability and mechanical properties of magnesium alloys are attractive for orthopaedic and cardiovascular applications. In order to study their cytotoxicity usually bone cells are used. However, after implantation, diverse and versatile cells are recruited and interact. Among the first ones coming into play are cells of the immune system, which are responsible for the inflammatory reaction. Macrophages play a central role in the inflammatory process due to the production of cytokines involved in the tissue healing but also in the possible failure of the implants. In order to evaluate the in vitro influence of the degradation products of magnesium-based alloys on cytokine release, the extracts of pure magnesium and two magnesium alloys (with gadolinium and silver as alloying elements) were examined in an inflammatory in vitro model. Human promonocytic cells (U937 cells) were differentiated into macrophages and further cultured with magnesium-based extracts for 1 and 3 days (simulating early and late inflammatory reaction phases), either at 37 °C or at 39 °C (mimicking normal and inflammatory conditions, respectively). All extracts exhibit very good cytocompatibility on differentiated macrophages. Results suggest that M1 and even more M2 profiles of macrophage were stimulated by the extracts of Mg. Furthermore, Mg-10Gd and Mg-2Ag extracts introduced a nuancing effect by rather inhibiting macrophage M1 profile. Magnesium-based biomaterials could thus induce a faster inflammation resolution while improving tissue repair. STATEMENT OF SIGNIFICANCE: Macrophage are the key-cells during inflammation and can influence the fate of tissue healing and implant performance. Magnesium-based implants are biodegradable and bioactive. Here we selected an in vitro system to model early and late inflammation and effect of pyrexia (37 °C versus 39 °C). We showed the beneficial and nuancing effects of magnesium (Mg) and the selected alloying elements (silver (Ag) and gadolinium (Gd)) on the macrophage polarisation. Mg extracts exacerbated simultaneously the macrophage M1 and M2 profiles while Mg-2Ag and Mg-10Gd rather inhibited the M1 differentiation. Furthermore, 39 °C exhibited protective effect by either decreasing cytokine production or promoting anti-inflammatory ones, with or without extracts. Mg-based biomaterials could thus induce a faster inflammation resolution while improving tissue repair.

567 Interplay of infarct territory related myocardial mechanics and prognostic implications following acute myocardial infarction

Background

Prognosis in acute myocardial infarction (AMI) depends on the amount of infarct related artery (IRA) subtended myocardium and associated damage but has not been described in great detail. Consequently, we sought to describe IRA associated pathophysiological consequences using cardiac magnetic resonance (CMR).

Methods

1235 AMI patients (n = 795 ST-elevation (STEMI) and 440 non-STEMI) underwent CMR following percutaneous coronary intervention. Blinded core-laboratory data were compared according to left anterior descending (LAD), left circumflex (LCx) and right coronary artery (RCA) regarding major adverse clinical events (MACE) within 12 months. Left ventricular (LV) global longitudinal/circumferential/radial (GLS/GCS/GRS) as well as left atrial (LA) total (εs), passive (εe) and active (εa) strains were determined using CMR-feature tracking. Tissue characterisation included infarct size (IS) and microvascular obstruction.

Results

LAD and LCx were associated with higher mortality compared to RCA lesions (4.6% and 4.4% vs 1.6%). LAD lesions showed largest IS (16.8%), largest ventricular (LV ejection fraction (EF) 47.4%, GLS -13.2%, GCS -20.8%) and atrial (εs 20.2%) impairment. There was less impairment in LCx (IS 11.8%, LVEF 50.8%, GLS -17.4%, GCS -25.0%, εs 20.7%) followed by RCA lesions (IS 11.3%, LVEF 50.8%, GLS -19.1%, GCS -26.6%, εs 21.7%). In AUC analyses εs (LAD, RCA) and GLS (LCx) best predicted MACE (AUC &gt; 0.69). Multivariate analyses identified εs (p = 0.017) in LAD and GLS (p = 0.034) in LCx infarcts as independent predictors of MACE.

Conclusions

CMR allows IRA specific phenotyping and characterisation of morphologic and functional changes. These alterations carry infarct specific prognostic implications and may represent novel diagnostic and therapeutic targets following AMI.

566 Myocardial left ventricular mechanical uniformity and adverse cardiac events following myocardial infarction

Background

Despite limitations as a standalone parameter, left ventricular ejection fraction (LVEF) is the preferred measure of myocardial function and marker for post-infarction risk stratification. LV myocardial uniformity may provide superior prognostic information after acute myocardial infarction (AMI), which was subject of this study.

Methods and Results:

Consecutive patients with AMI (n = 1082; median age 63 years; 75% male) undergoing cardiac magnetic resonance (CMR) in median 3 days after infarction were included in this multicenter, observational study. Circumferential and radial uniformity ratio estimates (CURE and RURE) were derived from CMR feature-tracking as markers of mechanical uniformity (values between 0 and 1 with 1 reflecting perfect uniformity). The clinical endpoint was the 12-month rate of major adverse cardiac events (MACE), consisting of all-cause death, re-infarction, and new congestive heart failure.

Patients with MACE (n = 73) had significantly impaired CURE [0.76 (IQR 0.67-0.86) versus 0.84 (IQR 0.76-0.89); p &lt; 0.001] and RURE [0.69 (IQR 0.60-0.79) versus 0.76 (IQR 0.67-0.83); p &lt; 0.001] compared to patients without events. While uniformity estimates did not provide independent prognostic information in the overall cohort, CURE below the median of 0.84 emerged as an independent predictor of outcome in post-infarction patients with LVEF &gt;35% (n = 959) even after adjustment for established prognostic markers (hazard ratio 1.99; 95% confidence interval 1.06-3.74; p = 0.033 in stepwise multivariable Cox regression analysis). In contrast, LVEF was not associated with adverse events in this subgroup of AMI patients.

Conclusions

CMR-derived estimates of mechanical uniformity are novel markers for risk assessment after AMI and CURE provides independent prognostic information in patients with preserved or only moderately reduced LVEF.

P5249Comprehensive invasive and non-invasive assessment of coronary artery lesions with and without hemodynamic significance

Background

There is limited knowledge about specific morphological parameters beyond the degree of stenosis to further characterize hemodynamically relevant coronary lesions.

Objective

The goal of this study was to identify certain morphological or molecular characteristics that distinguish hemodynamically significant from non-significant coronary lesions using various invasive and non-invasive measures.

Methods

This clinical study included patients with symptoms suggestive of CAD who underwent native T1-weighted CMR and gadofosveset-enhanced CMR as well as invasive coronary angiography between 2015 and 2016. OCT of the culprit vessel to determine the plaque type was performed in a subset of patients. Functional relevance of all lesions was examined using quantitative flow reserve (QFR-Angio). Hemodynamically significant lesions were defined as lesions with a QFR <0.8. Signal intensity (contrast-to-noise ratios; CNRs) on native T1-weighted CMR and gadofosveset-enhanced CMR was defined as a measure for intraplaque hemorrhage and endothelial permeability respectively.

Results

Overall 13 patients (n=28 coronary segments) were included, whose invasive coronary angiograms projections were eligible for QFR analysis. Segments containing lesions with a QFR <0.8 (n=9) were associated with significantly higher signal enhancement on Gadofosveset-enhanced CMR as compared to segments containing a hemodynamically non-relevant lesions (lesion-QFR>0.8; n=19) (7.0±4.9 vs. 3.0±2.6; p=0.02). No differences in signal enhancement were seen on native T1-weighted CMR (2.1±4.3 vs. 3.3±4.1; p=0.24). 66,7% (4 out of 6) of all vulnerable plaque and 33.3% (2 out of 6) of all non-vulnerable plaque (fibroatheroma) as assessed by OCT were hemodynamically significant lesions.

Conclusion

The findings of this small feasibility study suggest that hemodynamically significant lesions are more advanced and associated with a higher grade of endothelial permeability while the presence of intraplaque hemorrhage may not be associated with hemodynamically relevant coronary lesions.

P5284Fully automated quantification of biventricular volumes and function in cardiovascular magnetic resonance: applicability to clinical routine settings

Background

Cardiovascular magnetic resonance (CMR) represents the clinical gold standard for the assessment of biventricular morphology and function. Since manual post-processing is time-consuming and prone to observer variability, efforts have been directed towards automated volumetric quantification. In this study, we sought to validate the accuracy of a novel approach providing fully automated quantification of biventricular volumes and function in a “real-world” clinical setting.

Methods

Three-hundred CMR examinations were randomly selected from the local data base. Fully automatic quantification of left ventricular (LV) mass, LV and right ventricular (RV) end-diastolic and systolic volumes (EDV/ESV), stroke volume (SV) and ejection fraction (EF) were performed overnight using commercially available software. Parameters were compared to manual assessments. Sub-group analyses were further performed according to image quality, scanner field strength, the presence of implanted aortic valves and repaired Tetralogy of Fallot (ToF).

Results

Biventricular automatic segmentation was feasible in all 300 cases. Overall agreement between fully automated and manually derived LV parameters was good (LV-EF: intra-class correlation coefficient [ICC] 0.95; bias −2.5% [SD 5.9%]), whilst RV agreement was lower (RV-EF: ICC 0.72; bias 5.8% [SD 9.6%]). Lowest agreement was observed in case of severely altered anatomy, e.g. marked RV dilation but normal LV dimensions in repaired ToF (LV parameters ICC 0.73–0.91; RV parameters ICC 0.41–0.94) and/or reduced image quality (LV parameters ICC 0.86–0.95; RV parameters ICC 0.56–0.91), which was more common on 3.0T than on 1.5T.

Conclusions

Fully automated assessment of biventricular morphology and function is robust and accurate in a clinical routine setting with good image quality and can be performed without any user interaction. However, in case of demanding anatomy (e.g. repaired ToF, severe LV hypertrophy) or reduced image quality, quality check and manual re-contouring is still required.

Acknowledgement/Funding

DZHK - German Centre for Cardiovascular Research

P5255Culprit vessel related myocardial mechanics and prognostic implications following acute myocardial infarction

Background

Prognosis in acute myocardial infarction (AMI) depends on the amount of infarct related artery (IRA) subtended myocardium and associated damage but has not been described in great detail. Consequently, we sought to describe IRA associated pathophysiological consequences using cardiac magnetic resonance (CMR).

Methods

1235 AMI patients (n=795 ST-elevation (STEMI) and 440 non-STEMI) underwent CMR following percutaneous coronary intervention. Blinded core-laboratory data were compared according to left anterior descending (LAD), left circumflex (LCx) and right coronary artery (RCA) regarding major adverse clinical events (MACE) within 12 months. Left ventricular (LV) global longitudinal/circumferential/radial (GLS/GCS/GRS) as well as left atrial (LA) total (εs), passive (εe) and active (εa) strains were determined using CMR-feature tracking. Tissue characterisation included infarct size (IS) and microvascular obstruction.

Results

LAD and LCx were associated with higher mortality compared to RCA lesions (4.6% and 4.4% vs 1.6%). LAD lesions showed largest IS (16.8%), largest ventricular (LV ejection fraction (EF) 47.4%, GLS −13.2%, GCS −20.8%) and atrial (εs 20.2%) impairment. There was less impairment in LCx (IS 11.8%, LVEF 50.8%, GLS −17.4%, GCS −25.0%, εs 20.7%) followed by RCA lesions (IS 11.3%, LVEF 50.8%, GLS −19.1%, GCS −26.6%, εs 21.7%). In AUC analyses εs (LAD, RCA) and GLS (LCx) best predicted MACE (AUC>0.69). Multivariate analyses identified εs (p=0.017) in LAD and GLS (p=0.034) in LCx infarcts as independent predictors of MACE.

Conclusions

CMR allows IRA specific phenotyping and characterisation of morphologic and functional changes. These alterations carry infarct specific prognostic implications and may represent novel diagnostic and therapeutic targets following AMI.

Acknowledgement/Funding

DZHK - German Centre for Cardiovascular Research

P3097Atrioventricular mechanical coupling and major adverse cardiac events in female patients following acute ST elevation myocardial infarction

Background

Data on sex-specific outcomes following myocardial infarction (MI) are inconclusive with some evidence suggesting association of female sex and increased major adverse clinical events (MACE). Since underlying mechanisms remain elusive, we aimed to quantify the underlying phenotype using cardiovascular magnetic resonance (CMR) quantitative deformation imaging and tissue characterisation.

Methods

Amongst 8 centres across Germany, 795 ST-elevation MI (STEMI) patients underwent post-interventional CMR imaging. CMR feature-tracking (FT) was performed in a blinded core-laboratory. Left ventricular function was quantified using ejection fraction (LVEF) and global longitudinal/circumferential/radial strains (GLS/GCS/GRS). Left atrial function was assessed by reservoir (εs), conduit (εe) and booster pump function (εa). Tissue characterisation included infarct size (IS), microvascular obstruction (MO), area at risk and myocardial salvage index (MSI). Primary endpoint was the occurrence of major adverse clinical events (MACE) within 1 year.

Results

Female sex was associated with increased MACE (HR 1.96, 95% CI 1.13–3.42, p=0.017) but not independently of baseline confounders (p=0.526) with women being older, more often diabetic and hypertensive (p<0.001) and of higher Killip-class (p=0.010). Tissue characterisation was similar between sexes. Women showed impaired atrial (εs p=0.011, εe p<0.001) but increased systolic ventricular mechanics (GLS p=0.001, LVEF p=0.048). Ventricular strain was associated with MACE irrespective of all univariate significant baseline characteristics (GLS HR 1.08, 95% CI 1.01–1.16, p=0.036 and GCS HR 1.07, 95% CI 1.00–1.14, p=0.040).

Conclusion

Atrial function is reduced in women following STEMI, while ventricular systolic function is increased. This may reflect ventricular diastolic failure with systolic compensation, which is independently associated with MACE and may add to sex-specific prognosis evaluation.

Acknowledgement/Funding

DZHK - German Centre for Cardiovascular Research

P11.26 Genome-wide shRNA screen identifies candidate genes driving glioblastoma invasion

BACKGROUND

A major hallmark of glioblastoma (GBM) is its highly invasive capacity, contributing to its aggressive behaviour. Since invasive cells cannot be easily removed by surgery or irradiation, they are left behind and eventually result in lethal recurrence. Therefore, a better understanding of the invasion process and of the key molecular players underlying the invasive capacities of GBM may lead to the identification of new therapeutic targets for GBM patients.

MATERIAL AND METHODS

To identify candidate genes responsible for invasion, a genome-wide shRNA screen was performed in patient-derived GBM sphere cultures. The phenotype of the most promising candidate was validated in in vitro invasion assays, ex vivo brain slice cultures and in vivo orthotopic xenografts in mice. Gene knockdown in invasive GBM cell lines was compared with overexpression in non-invasive cells. RNA sequencing of knockdown cells, along with the generation of deletion constructs were applied to uncover the mechanisms regulating invasion.

RESULTS

Through a whole genome shRNA screen, a zinc-finger containing protein was identified as an invasion essential candidate gene. Knockdown of this gene confirmed a strong decrease in invasion capacity in two highly invasive GBM cell lines. In contrast, gene overexpression switched non-invasive GBM cells to an invasive phenotype. Deletion of either one or both zinc-finger motifs led to decreased invasion indicating that the two zinc-finger motifs are essential for regulating invasion. Mutation of the nuclear localisation signal resulted in retention of the protein in the cytoplasm and loss of the invasion phenotype demonstrating that the protein activity is required in the nucleus. Gene expression analyses revealed that invasion-related genes are significantly regulated by the candidate gene once it is localized in the nucleus.

CONCLUSION

We identified a zinc-finger containing protein as a novel driver of GBM invasion, presumably through a transcription factor activity resulting in the induction of an invasive transcriptional program. This protein and its downstream pathway may represent a novel promising target to overcome invasive capacities in GBM.

P11.09 Pan-RTK inhibition of sLRIG1 mediates AXL downregulation in Glioblastoma

INTRODUCTION

Aberrant regulation of receptor tyrosine kinase (RTK) activity is characteristic of Glioblastoma (GBM). However, RTK-based targeted therapies have been largely unsuccessful in GBM patients, partially due to the complexity and redundance of RTK signaling. LRIG1 (Leucine-rich Repeats and ImmunoGlobulindomains protein 1) is known as an endogenous inhibitor of epidermal growth factor receptor (EGFR) during health and disease, however its mechanism of action is poorly understood. We previously showed that the soluble form of LRIG1 potently inhibits of GBM growth in vivo, irrespective of EGFR expression level and status, suggesting the involvement of other RTKs. Here, we aimed to shed light on the molecular mechanisms underlying its anti-cancer activity.

MATERIAL AND METHODS

We generated a recombinant human soluble LRIG1 protein by expressing LRIG1 ectodomain in insect cells via baculovirus infection and subsequent His-tag purification. rh-sLRIG1 was applied in the medium of classical GBM cell lines, patient-derived GBM stem-like cells and patient-derived 3D tumor organoids. Using different cell-based assays, cell proliferation, invasion, cell morphology, as well as protein expression and protein-protein interactions were investigated.

RESULTS

We find that recombinant sLRIG1 efficiently reduces proliferation, invasion and viability of GBM cells and patient-derived organoids, and modulates cytoskeleton proteins and cell shape. In line with previous data, the effect of recombinant sLRIG1 is independent of EGFR expression. Interestingly sLRIG1 regulates several RTKs by direct protein downregulation, including AXL, while EGFR expression is not affected. At the molecular level, we find that sLRIG1 interferes with AXL dimerization, while no protein interaction with EGFR is detected.

CONCLUSION

We identify AXL as a novel LRIG1 target and provide evidence that sLRIG1-mediated RTK downregulation requires direct protein-protein interaction. These data pave the way for a potential therapeutic application of recombinant sLRIG1 in the inhibition of growth factor signaling in GBM.

Priorities for future research into asthma diagnostic tools: A PAN-EU consensus exercise from the European asthma research innovation partnership (EARIP)

The diagnosis of asthma is currently based on clinical history, physical examination and lung function, and to date, there are no accurate objective tests either to confirm the diagnosis or to discriminate between different types of asthma. This consensus exercise reviews the state of the art in asthma diagnosis to identify opportunities for future investment based on the likelihood of their successful development, potential for widespread adoption and their perceived impact on asthma patients. Using a two-stage e-Delphi process and a summarizing workshop, a group of European asthma experts including health professionals, researchers, people with asthma and industry representatives ranked the potential impact of research investment in each technique or tool for asthma diagnosis and monitoring. After a systematic review of the literature, 21 statements were extracted and were subject of the two-stage Delphi process. Eleven statements were scored 3 or more and were further discussed and ranked in a face-to-face workshop. The three most important diagnostic/predictive tools ranked were as follows: "New biological markers of asthma (eg genomics, proteomics and metabolomics) as a tool for diagnosis and/or monitoring," "Prediction of future asthma in preschool children with reasonable accuracy" and "Tools to measure volatile organic compounds (VOCs) in exhaled breath."

[The use of sunglasses during leisure time and work : Lack of prevention of sun-induced eye damage]

OBJECTIVE

This study aimed at collecting representative national data on the use of sunglasses on sunny summer days during leisure time or work as well as identifying population and professional groups with a pronounced lack of preventive measures to avoid sun-induced eye damage.

MATERIAL AND METHODS

Within the representative National Cancer Aid Monitoring, data on the use of sunglasses during leisure time was assessed among 3000 individuals aged 14-45 years in 2015, as well as on the use during outdoor work among 485 workers aged 14-45 years in 2016. Associations between the use of sunglasses and sociodemographic characteristics were assessed with the χ²-test. Additionally, descriptive and bivariate methods were used to assess connections between the use of sunglasses at work and each professional group.

RESULTS

While more than half of the general population normally or often wear sunglasses on a sunny summer day, only one third of outdoor workers do so. While approximately every seventh individual surveyed never wears sunglasses during leisure time, among outdoor workers it is one out of three. The use during leisure time increases with age.

DISCUSSION

Use of sunglasses during work could be supported by targeted information on UV-induced eye damage by ophthalmologists and company physicians with additional support from accident insurances and employers. Concerning preventive measures occupational groups such as landscapers, farmers and bricklayers who are strongly exposed to sunlight but rarely wear sunglasses are important groups.

Legislation of direct-to-consumer genetic testing in Europe: a fragmented regulatory landscape

Despite the increasing availability of direct-to-consumer (DTC) genetic testing, it is currently unclear how such services are regulated in Europe, due to the lack of EU or national legislation specifically addressing this issue. In this article, we provide an overview of laws that could potentially impact the regulation of DTC genetic testing in 26 European countries, namely Austria, Belgium, Cyprus, the Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Ireland, Italy, Latvia, Lithuania, Luxembourg, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, the Netherlands and the United Kingdom. Emphasis is placed on provisions relating to medical supervision, genetic counselling and informed consent. Our results indicate that currently there is a wide spectrum of laws regarding genetic testing in Europe. There are countries (e.g. France and Germany) which essentially ban DTC genetic testing, while in others (e.g. Luxembourg and Poland) DTC genetic testing may only be restricted by general laws, usually regarding health care services and patients' rights.

Occupational exposure to ultrafine particles in police officers: no evidence for adverse respiratory effects

Background

Inhalation exposure to fine and ultrafine particles (UFPs) has been associated with respiratory diseases. However, little is known on the quality, threshold levels and concentration of these particles causing adverse health effects.

Methods

The impact of occupational exposure to submicrometer and UFPs was assessed in 30 healthy police shooting instructors by clinical investigation, self-assessment questionnaire, sputum and spirometry and compared to a control group. General laboratory chemistry parameters, circulating cytokines (interleukin [IL]-2, IL-4, IL-5, IL-6, IL-8, interferon-gamma [IFN-γ]), and granulocyte macrophage colony-stimulating factor (GM-CSF) in serum were measured. UFP exposure was recorded by Scanning Mobility Particle Sizer.

Results

Concentrations of submicrometer sized airborne particles (< 700 nm) measured between 3.34 × 10⁵/cm³ and 7.58 × 10⁵/cm³ at shooting sites, with highest concentrations found in the UFP range (< 100 nm). The size of the monodispersed particles ranged from 54.74 ± 16.25 nm to 98.19 ± 22.83 nm. Short term exposure (4 h) to high levels of UFPs caused an increase of IFN-γ in exposed subjects (p = 0.022). 24 h after exposure a significant decrease of IgG, albumin fibrinogen and factor VII was found. Neither directly after 4 h of high levels UFPs exposure nor 24 h after exposure subjective complaints or objective measurements indicating adverse respiratory effects in exposed subjects were found.

Conclusions

No consistent indications for adverse respiratory or inflammatory effects directly following exposure and 24 h after exposure to high levels of UFPs in our study group were detected. However we showed the assessment of short-term exposure effects at a genuine occupational setting, which might is relevant when a risk assessment of high level occupational exposures to UFPs is considered.

Evolution of the IgE and IgG repertoire to a comprehensive array of allergen molecules in the first decade of life

BACKGROUND

In early childhood, the allergen-specific IgG repertoire is mainly directed to animal and vegetable food molecules and infrequently to airborne molecules. It is unknown whether this early pattern is maintained throughout childhood.

OBJECTIVE

To investigate the evolution of IgG and IgE responses to a broad panel of allergenic molecules from birth to age 10 years.

METHODS

We examined the sera collected between birth and age 10 years from participants in the German Multicentre Allergy Study, a birth cohort born in 1990. The IgE (cutoff ≥0.30 ISU) and IgG (cutoff ≥0.10 ISU) responses to 35 genuine allergenic molecules were measured with a multiplex microarray approach (ImmunoCAP ISAC™).

RESULTS

IgE responses were mostly directed against a restricted group of airborne molecules, with a sequence and prevalence hierarchy (Phl p 1> Bet v 1> Fel d 1> Phl p 5> Der p 2> Der p 1) largely maintained over time. Conversely, the IgG repertoire was much broader, starting with animal foodborne, then spreading to vegetable foodborne and finally to airborne molecules. A strong and persistent IgG response to a given airborne molecule almost invariably preceded or accompanied an IgE response to that molecule.

CONCLUSIONS

The evolution of IgG and IgE responses throughout childhood differs widely at population level. IgG responses are mostly directed to animal food allergens, while IgE responses are dominated by airborne allergens. However, a strong IgG response almost invariably precedes or accompanies the appearance of IgE to the same molecule in specifically sensitized subjects.

[Guideline for the Diagnosis and Treatment of Asthma - Guideline of the German Respiratory Society and the German Atemwegsliga in Cooperation with the Paediatric Respiratory Society and the Austrian Society of Pneumology]

The present guideline is a new version and an update of the guideline for the diagnosis and treatment of asthma, which replaces the previous version for german speaking countries from the year 2006. The wealth of new data on the pathophysiology and the phenotypes of asthma, and the expanded spectrum of diagnostic and therapeutic options necessitated a new version and an update. This guideline presents the current, evidence-based recommendations for the diagnosis and treatment of asthma, for children and adolescents as well as for adults with asthma.

B-cell activating factor BAFF reflects patients' immunological risk profile after kidney transplantation

The B-cell activating factor BAFF plays an important role in the development and maturation of B-lymphocytes, which can contribute to the generation of donor-specific antibodies and thus may influence graft function and graft survival. Inconsistent data on the role of BAFF levels after renal transplantation for the formation of donor-specific antibodies and the contribution for allograft rejection exist. The aim of the current study was to determine to what extent the degree of pre-immunization is reflected by each patient's BAFF levels before transplantation and in the follow-up. Furthermore, the impact of BAFF on allograft rejection frequency as well as severity and resulting allograft function over time was analyzed. Additionally, the impact of viral infections on BAFF levels after transplantation - as a potential confounder - was examined. For this purpose, a group of pre-sensitized patients (PRA>0%, (52±24% on average), n=40) was compared with non-sensitized patients (PRA=0%, n=62) and in a subsequent analysis stratification in accordance to the detected BAFF level was performed. Pre-sensitized patients had significantly higher BAFF levels before transplantation and suffered significantly more often from early steroid-resistant, mainly antibody-mediated rejections. A result which was confirmed also in highly sensitized patients with PRA levels >50%. Additionally, in the follow-up patients with either rising BAFF levels over time or BAFF levels above the median also had significantly more often antibody mediated rejections. Additionally, patients with BAFF levels above detected median even displayed impaired creatinine values as well as an induced eGFR slope up to month 48 after transplantation. The occurrence of viral infections (CMV, BKV) was only an additional influencing factor in the absence of concomitant allograft rejections. Therefore, the B-cell proliferation factor BAFF appears not only to reflect the immunological risk profile of patients in the context of kidney transplantation, it may possibly be further developed as a predictor of patients with an increased risk profile for subsequent allograft rejection and impaired allograft function.