IOANNIS NTALAS

Dr. IOANNIS NTALAS

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Research Focus & Metrics

Academic Career Length

14Years (2013-Present)

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

Representative Publications

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1 February 2018 in Journal of Cardiovascular Magnetic Resonance
Verified
Journal Article
Open access
PDF file
AVAdriana D. M. Villa
Adriana D. M. Villa
LCLaura Corsinovi
Laura Corsinovi
INIOANNIS NTALAS
IOANNIS NTALAS
XMXenios Milidonis
Xenios Milidonis
CSCian M. Scannell
Cian M. Scannell
ACAmedeo Chiribiri
Amedeo Chiribiri
Clinical evaluation of stress perfusion cardiovascular magnetic resonance (CMR) is currently based on visual assessment and has shown high diagnostic accuracy in previous clinical trials, when performed by expert readers or core laboratories. However, these results may not be generalizable to clinical practice, particularly when less experienced readers are concerned. Other factors, such as the level of training, the extent of ischemia, and image quality could affect the diagnostic accuracy. Moreover, the role of rest images has not been clarified. The aim of this study was to assess the diagnostic accuracy of visual assessment for operators with different levels of training and the additional value of rest perfusion imaging, and to compare visual assessment and automated quantitative analysis in the assessment of coronary artery disease (CAD). We evaluated 53 patients with known or suspected CAD referred for stress-perfusion CMR. Nine operators (equally divided in 3 levels of competency) blindly reviewed each case twice with a 2-week interval, in a randomised order, with and without rest images. Semi-automated Fermi deconvolution was used for quantitative analysis and estimation of myocardial perfusion reserve as the ratio of stress to rest perfusion estimates. Level-3 operators correctly identified significant CAD in 83.6% of the cases. This percentage dropped to 65.7% for Level-2 operators and to 55.7% for Level-1 operators (p < 0.001). Quantitative analysis correctly identified CAD in 86.3% of the cases and was non-inferior to expert readers (p = 0.56). When rest images were available, a significantly higher level of confidence was reported (p = 0.022), but no significant differences in diagnostic accuracy were measured (p = 0.34). Our study demonstrates that the level of training is the main determinant of the diagnostic accuracy in the identification of CAD. Level-3 operators performed at levels comparable with the results from clinical trials. Rest images did not significantly improve diagnostic accuracy, but contributed to higher confidence in the results. Automated quantitative analysis performed similarly to level-3 operators. This is of increasing relevance as recent technical advances in image reconstruction and analysis techniques are likely to permit the clinical translation of robust and fully automated quantitative analysis into routine clinical practice.

1 January 2019 in Journal of Cardiovascular Magnetic Resonance
Verified
Journal Article
Open access
PDF file
RHRobert J. Holtackers
Robert J. Holtackers
CHCaroline Van De Heyning
Caroline Van De Heyning
MNMuhummad Sohaib Nazir
Muhummad Sohaib Nazir
IRImran Rashid
Imran Rashid
INIOANNIS NTALAS
IOANNIS NTALAS
ACAmedeo Chiribiri
Amedeo Chiribiri
For two decades, bright-blood late gadolinium enhancement (LGE) cardiovascular magnetic resonance (CMR) has been considered the reference standard for the non-invasive assessment of myocardial viability. While bright-blood LGE can clearly distinguish areas of myocardial infarction from viable myocardium, it often suffers from poor scar-to-blood contrast, making subendocardial scar difficult to detect. Recently, we proposed a novel dark-blood LGE approach that increases scar-to-blood contrast and thereby improves subendocardial scar conspicuity. In the present study we sought to assess the clinical value of this novel approach in a large patient cohort with various non-congenital ischemic and non-ischemic cardiomyopathies on both 1.5 T and 3 T CMR scanners of different vendors. Three hundred consecutive patients referred for clinical CMR were randomly assigned to a 1.5 T or 3 T scanner. An entire short-axis stack and multiple long-axis views were acquired using conventional phase sensitive inversion recovery (PSIR) LGE with TI set to null myocardium (bright-blood) and proposed PSIR LGE with TI set to null blood (dark-blood), in a randomized order. The bright-blood LGE and dark-blood LGE images were separated, anonymized, and interpreted in a random order at different time points by one of five independent observers. Each case was analyzed for the type of scar, per-segment transmurality, papillary muscle enhancement, overall image quality, observer confidence, and presence of right ventricular scar and intraventricular thrombus. Dark-blood LGE detected significantly more cases with ischemic scar compared to conventional bright-blood LGE (97 vs 89, p = 0.008), on both 1.5 T and 3 T, and led to a significantly increased total scar burden (3.3 ± 2.4 vs 3.0 ± 2.3 standard AHA segments, p = 0.015). Overall image quality significantly improved using dark-blood LGE compared to bright-blood LGE (81.3% vs 74.0% of all segments were of highest diagnostic quality, p = 0.006). Furthermore, dark-blood LGE led to significantly higher observer confidence (confident in 84.2% vs 78.4%, p = 0.033). The improved detection of ischemic scar makes the proposed dark-blood LGE method a valuable diagnostic tool in the non-invasive assessment of myocardial scar. The applicability in routine clinical practice is further strengthened, as the present approach, in contrast to other recently proposed dark- and black-blood LGE techniques, is readily available without the need for scanner adjustments, extensive optimizations, or additional training.

1 March 2018 in Journal of Cardiovascular Computed Tomography
Verified
Journal Article
Open access
JKJúlia Karády
Júlia Karády
INIOANNIS NTALAS
IOANNIS NTALAS
BPBernard Prendergast
Bernard Prendergast
CBChristopher Blauth
Christopher Blauth
SNSteven Niederer
Steven Niederer
RRRonak Rajani
Ronak Rajani
There is considerable interest in transcatheter prosthetic valve treatment for mitral valve disease in high-risk individuals. Although the presence of mitral annular calcium (MAC) may provide an anchoring zone for such devices, results to date have been modest with reported technical failure rates approaching 30% in specialist centers. This in part relates to the risk of left ventricular outflow tract obstruction and device dislodgment but also to the lack of specific imaging guidelines to plan for such procedures. We present the use of finite element analysis and computer simulation based on cardiac CT in three patients with severe MAC in whom transcatheter devices were considered. In the first two cases, the computer simulations were performed after the clinical procedure and were concordant with the clinical outcome. For the third case, computer simulation was performed prior to the clinical procedure. This indicated unsuitability for transcatheter device deployment and a subsequent medical management was adopted. Overall, our initial results suggest that computer simulation may have the potential to improve patient selection for transcatheter mitral valve replacement in the presence of significant MAC.

1 March 2022 in Hellenic Journal of Cardiology
Verified
Journal Article
Open access
Nikolaos KadoglouNikolaos Kadoglou
Nikolaos Kadoglou
CPConstantinos Hristou Papadopoulos
Constantinos Hristou Papadopoulos
KPKonstantinos G. Papadopoulos
Konstantinos G. Papadopoulos
SKStefanos Karagiannis
Stefanos Karagiannis
IKIlias Karabinos
Ilias Karabinos
PNPetros Nihoyannopoulos
Petros Nihoyannopoulos
Stress echocardiography (SE) is a well-established and valid technique, widely-used for the diagnostic evaluation of patients with ischemic and non-ischemic cardiac diseases. This statement of the Echocardiography Working Group of the Hellenic Society of Cardiology summarizes the consensus of the writing group regarding the applications of SE, based on the expertise of their members and on a critical review of current medical literature. The main objectives of the consensus document include a comprehensive review of SE methodology and training, focusing on the preparation, the protocols used and the analysis of the SE images and an updated, evidence-based knowledge about SE applications on ischemic and non-ischemic heart diseases, such as in cardiomyopathies, heart failure and valvular heart disease.

1 October 2013 in International Journal of Cardiology
Verified
Journal Article
Closed access
DADimitrios Alexopoulos
Dimitrios Alexopoulos
JGJohn A. Goudevenos
John A. Goudevenos
IXIoanna Xanthopoulou
Ioanna Xanthopoulou
Spyridon G. DeftereosSpyridon G. Deftereos
Spyridon G. Deftereos
GSGeorge Sitafidis
George Sitafidis
CSChristodoulos Stefanadis
Christodoulos Stefanadis

21 August 2013 in Angiology
Verified
Journal Article
Closed access
INIOANNIS NTALAS
IOANNIS NTALAS
HMHaralampos J. Milionis
Haralampos J. Milionis
AKAnastazia A. Kei
Anastazia A. Kei
KKKallirroi I. Kalantzi
Kallirroi I. Kalantzi
JGJohn A. Goudevenos
John A. Goudevenos
Ischemic heart disease and cerebrovascular disease remain major health problems with associated mortality and quality-of-life consequences. Antiplatelet agents, including thienopyridines and the new P2Y12 inhibitors, have been shown to improve survival in the secondary prevention setting. We review the available evidence on the effectiveness and safety of previous established as well as novel antithrombotic agents in the secondary prevention of cardiovascular disease with a special focus on cerebrovascular disease.