Caglayan Demirel

Dr. Caglayan Demirel

orcid

Research Focus & Metrics

Academic Career Length

4Years (2023-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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1 December 2023 in Radiology
Verified
Journal Article
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BBBenedikt Bernhard
Benedikt Bernhard
ZLZoe Leib
Zoe Leib
SDStephan Dobner
Stephan Dobner
CDCaglayan Demirel
Caglayan Demirel
Federico CaobelliFederico Caobelli
Federico Caobelli
CGChristoph Gräni
Christoph Gräni
Background Transthyretin amyloid cardiomyopathy (ATTR-CM) often coexists with severe aortic stenosis (AS). Although strain analysis from cardiac MRI and echocardiography was demonstrated to predict coexisting ATTR-CM, comparable data from four-dimensional (4D) cardiac CT are lacking despite wide availability. Purpose To evaluate the diagnostic performance of 4D cardiac CT-derived parameters in identifying ATTR-CM in older adults considered for transcatheter aortic valve implantation (TAVI). Materials and Methods This prospective single-center screening study for ATTR-CM included consecutive patients with severe AS considered for TAVI who underwent 4D cardiac CT between August 2019 and August 2021 approximately 1 day before technetium 99m (99mTc) 3,3-diphosphono-1,2-propanodicarboxylic-acid (DPD) scintigraphy. The diagnostic performance of CT-based left ventricular (LV), right ventricular, and left atrial dimensions, ejection fraction (EF), and myocardial strain were evaluated against 99mTc-DPD scintigraphy as the reference standard to identify ATTR-CM. Predictors and an unweighted cardiac CT score were validated with internal bootstrapping. The assignment of variables to the score was based on cutoff values achieving the highest Youden index J. Results Among 263 participants (mean age, 83 years ± 4.6 [SD]; 149 male and 114 female participants), 99mTc-DPD scintigraphy (Perugini grade 2 or 3) confirmed coexisting ATTR-CM in 27 (10.3%). CT-derived LV mass index, LV and LA global longitudinal strain (GLS), and relative apical longitudinal strain each predicted the presence of ATTR-CM with an area under the curve (AUC) of at least 0.70. Implementing these parameters with cutoff values of 81 g/m2 or higher, -14.9% or higher, less than 11.5%, and 1.7 or higher in the CT score, respectively, yielded high diagnostic performance (AUC = 0.89; 95% CI: 0.81, 0.94; P < .001) robust to internal bootstrapping validation (AUC = 0.88; 95% CI: 0.82, 0.94). If two criteria were fulfilled, the sensitivity and specificity in the detection of ATTR-CM were 96.3% (95% CI: 81.0, 99.9) and 58.9% (95% CI: 52.3, 65.2), respectively. Conclusion When compared against 99mTc-DPD scintigraphy as the reference standard, routine 4D cardiac CT in older adults considered for TAVI provided high diagnostic performance in the detection of concomitant ATTR-CM by assessing LV and left atrial GLS, relative apical longitudinal strain, and LV mass index. ClinicalTrials.gov registration no.: NCT04061213 © RSNA, 2023 Supplemental material is available for this article. See also the editorial by Tavakoli and Onder in this issue.

1 July 2025 in Circulation: Cardiovascular Imaging
Verified
Journal Article
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SKSophia Koschatko
Sophia Koschatko
GHGregor Heitzinger
Gregor Heitzinger
NPNoemi Pavo
Noemi Pavo
GSGeorg Spinka
Georg Spinka
PBPhilipp E. Bartko
Philipp E. Bartko
PBPhilipp E. Bartko
Philipp E. Bartko
BACKGROUND: Severe functional mitral regurgitation (fMR) is a heterogenous disease that exhibits different underlying pathophysiological mechanisms and represents independent entities. The aim of this study was to characterize remodeling patterns defined by the left atrial (LA) to left ventricular (LV) volume ratio in patients with severe fMR and heart failure, and to examine its prognostic implications. METHODS: A total of 13 052 patients with fMR were included. Based on the LA/LV volume ratio, patients with severe fMR were divided into 2 distinct groups: predominant LV remodeling (PLVR [ratio ≤0.56, n=581]) and predominant LA remodeling (PLAR [ratio >0.56, n=582]). RESULTS: Patients with PLAR were more often female, with the peak age a decade later. PLAR was associated with lower leaflet tethering indices, as indicated by the leaflet tenting area (PLVR versus PLAR: 227 mm 2 versus 181 mm 2 , P <0.001) and angles (PLVR versus PLAR: posterior leaflet: 42° versus 36°, P <0.001; anterior leaflet: 28° versus 23°, P <0.001). PLAR was the predominant subtype in heart failure with preserved (76%) and heart failure with mildly reduced ejection fraction (61%), but a significant proportion could be observed in heart failure with reduced ejection fraction (32%). The median follow-up time for severe fMR was 66 months (interquartile range, 60–85). After 4 years, 42.1% with PLAR and 34.1% with PLVR had died. At 8 years, 57.3% of patients with PLAR, and 49.6% of patients with PLVR had died. Compared with PLVR, PLAR showed excess mortality, with a hazard ratio of 1.37 ([95% CI, 1.13–1.65]; P =0.001) in the univariate analysis. This effect remained after multivariable adjustment. CONCLUSIONS: The LA/LV volume ratio indicates the prevailing remodeling pattern in severe fMR. It is associated with morphological features of valve apparatus distortion resulting from differential remodeling. A strong correlation is observed between the LA/LV volume ratio and mortality.

26 February 2024 in Journal of Clinical Medicine
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Journal Article
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CDCaglayan Demirel
Caglayan Demirel
CRChristoph Fritz Rothenbühler
Christoph Fritz Rothenbühler
MHMarkus Huber
Markus Huber
MSMichelle Schweizer
Michelle Schweizer
ITInga Todorski
Inga Todorski
GEGabor Erdoes
Gabor Erdoes
Background: Transcatheter aortic valve replacement (TAVR) is a treatment option for severe aortic valve stenosis. Pre-TAVR assessments, extending beyond anatomy, include evaluating frailty. Potential frailty parameters in pre-TAVR computed tomography (CT) scans are not fully explored but could contribute to a comprehensive frailty assessment. The primary objective was to investigate the impact of total muscle area (TMA) and visceral adipose tissue (VAT) as frailty parameters on 5-year all-cause mortality in patients undergoing TAVR. Methods: Between 01/2017 and 12/2018, consecutive TAVR patients undergoing CT scans enabling TMA and VAT measurements were included. Results: A total of 500 patients qualified for combined TMA and VAT analysis. Age was not associated with a higher risk of 5-year mortality (HR 1.02, 95% CI: 0.998–1.049; p = 0.069). Body surface area normalized TMA (nTMA) was significantly associated with 5-year, all-cause mortality (HR 0.927, 95% CI: 0.927–0.997; p = 0.033), while VAT had no effect (HR 1.002, 95% CI: 0.99–1.015; p = 0.7). The effect of nTMA on 5-year, all-cause mortality was gender dependent: the protective effect of higher nTMA was found in male patients (pinteraction: sex × nTMA = 0.007). Conclusions: Normalized total muscle area derived from a routine CT scan before transcatheter aortic valve replacement complements frailty assessment in patients undergoing TAVR.

1 December 2023 in APL Bioengineering
Verified
Journal Article
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Silje Ekroll JahrenSilje Ekroll Jahren
Silje Ekroll Jahren
CDCaglayan Demirel
Caglayan Demirel
KBKaroline-Marie Bornemann
Karoline-Marie Bornemann
Pascal CorsoPascal Corso
Pascal Corso
SSStefan Stortecky
Stefan Stortecky
Dominik ObristDominik Obrist
Dominik Obrist
The etiology of transcatheter heart valve thrombosis (THVT) and the relevance of the aortic root geometry on the occurrence of THVT are largely unknown. The first aim of this pilot study is to identify differences in aortic root geometry between THVT patients and patients without THVT after transcatheter aortic valve implantation (TAVI). Second, we aim to investigate how the observed difference in aortic diameters affects the aortic flow using idealized computational geometric models. Aortic dimension was assessed using pre-TAVI multi-detector computed tomography scans of eight patients with clinical apparent THVT and 16 unaffected patients (two for each THVT patient with same valve type and size) from the Bern-TAVI registry. Among patients with THVT the right coronary artery height was lower (−40%), and sinotubular junction (STJ) and ascending aorta (AAo) diameters tended to be larger (9% and 14%, respectively) compared to the unaffected patients. Fluid–structure interaction (FSI) in two idealized aortic models with the observed differences in STJ and AAo diameter showed higher backflow rate at the STJ (+16%), lower velocity magnitudes in the sinus (−5%), and higher systolic turbulent dissipation rate in the AAo (+8%) in the model with larger STJ and AAo diameters. This pilot study suggests a direct effect of the aortic dimensions on clinically apparent THVT. The FSI study indicates that larger STJ and AAo diameters potentially favor thrombus formation by increased backflow rate and reduced wash-out efficiency of the sinus. The reported observations require clinical validation but could potentially help identifying patients at risk for THVT.

17 January 2024 in European Heart Journal - Cardiovascular Imaging
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Journal Article
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CDCaglayan Demirel
Caglayan Demirel
MWMax Paul Winter
Max Paul Winter
CNChristian Nitsche
Christian Nitsche
SKSophia Koschatko
Sophia Koschatko
CJCharlotte Jantsch
Charlotte Jantsch
PBPhilipp E. Bartko
Philipp E. Bartko
Transcatheter aortic valve replacement (TAVR) revolutionized the therapy of severe aortic stenosis (AS) with rising numbers. Mixed aortic valve disease (MAVD) treated by TAVR is gaining more interest, as those patients represent a more complex cohort as compared with isolated AS. However, concerning long-term outcome for this cohort only, limited data are available. The aim of the study is to assess the prevalence of MAVD in TAVR patients, investigate its association with paravalvular regurgitation (PVR), and analyse its impact on long-term mortality after TAVR We conducted a registry-based cohort study using the Vienna TAVR registry, enrolling patients who underwent TAVR at Medical University of Vienna between January 2007 and May 2020 with available transthoracic echocardiography before and after TAVR (n = 880). Data analysis included PVR incidence and long-term survival outcomes. A total of 647 (73.52%) out of 880 patients had ≥ mild aortic regurgitation next to severe AS. MAVD was associated with PVR compared with isolated AS with an odds ratio of 2.06, 95% confidence interval (CI): 1.51–2.81 (P = <0.001). More than mild PVR after TAVR (n = 168 out of 880: 19.09%) was related to higher mortality compared with the absence of PVR with a hazard ratio (HR) of 1.33, 95% CI: 1.05– 1.67 (P = 0.016). MAVD patients developing ≥ mild PVR after TAVR were also associated with higher mortality compared with the absence of PVR with an HR of 1.30 and 95% CI: 1.04–1.62 (P = 0.022). MAVD is prevalent among TAVR patients and presents unique challenges, with increased PVR risk and worse outcomes compared with isolated AS. Long-term survival for MAVD patients, not limited to those developing PVR post-TAVR, is compromised. Earlier intervention before the occurrence of structural myocardial damage or surgical valve replacement might be a potential workaround to improve outcomes. (A) Flowchart, (B) Kaplan–Meier estimates of survival comparing MAVD patients with the presence or absence of PVR after TAVR; (C) Kaplan–Meier estimates of survival comparing MAVD with isolated AS, and (D) Kaplan–Meier estimates of survival according to the presence or absence of ≥ mild PVR after TAVR.

Verified
Journal Article
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Matthias KoschutnikMatthias Koschutnik
Matthias Koschutnik
CBChristina Brunner
Christina Brunner
CNChristian Nitsche
Christian Nitsche
CDCarolina Donà
Carolina Donà
VDVarius Dannenberg
Varius Dannenberg
PBPhilipp E. Bartko
Philipp E. Bartko
Background: Inflammatory indices have been proposed as simple and routinely obtainable markers of systemic inflammation in cardiac disease. This study investigated whether the neutrophil-to-lymphocyte ratio (NLR), the monocyte-to-lymphocyte ratio (MLR), and the pan-immune inflammation value (PIV) serve as biomarkers for risk stratification and outcomes measures in patients with severe aortic stenosis (AS) following valve replacement (AVR). Methods: In this retrospective analysis (January 2017–June 2022), patients with AS underwent pre-procedural cardiovascular magnetic resonance (CMR) imaging and were assigned a treatment strategy by a multidisciplinary Heart Team: (1) transcatheter AVR, (2) surgical AVR, or (3) no valvular intervention. Kaplan–Meier estimates and regression analyses were used to demonstrate associations between the NLR, MLR, and PIV with myocardial fibrosis—assessed by late gadolinium enhancement (LGE) and extracellular volume (ECV) on CMR—and a combined endpoint of heart failure hospitalizations and all-cause mortality. Results: A total of 356 patients (median age: 80 years, 50% male) were followed for a median of 40 months, during which 162 (46%) reached the combined endpoint. Linear regression identified C-reactive protein, but not the presence of LGE or elevated ECV, as the only independent predictor of all three inflammatory indices (p for all <0.001). After multivariable adjustment for clinical (EuroSCORE II), laboratory (baseline N-terminal prohormone of brain natriuretic peptide [NT-proBNP] and C-reactive protein), and imaging parameters (AV mean pressure gradient, right ventricular ejection fraction, and ECV), the above-the-upper-quartile NLR (adjusted hazard ratio [aHR]: 1.45, 95%-confidence interval [CI]: 1.01–1.92, p = 0.042), MLR (aHR: 1.48, 95%-CI: 1.05–2.09, p = 0.025), and PIV (aHR: 1.56, 95%-CI: 1.11–2.21, p = 0.011) remained significantly associated with adverse outcomes. Following AVR, the median NLR (3.5 to 3.4) and PIV (460 to 376) showed a significant post-procedural decline compared to baseline (p ≤ 0.019 for both). Conclusions: Inflammatory indices are readily available biomarkers independently associated with adverse outcomes in severe AS following AVR. However, no significant relationship was observed between the NLR, MLR, PIV, and myocardial fibrosis on CMR.