Romain Didier

Romain Didier


Research Focus & Metrics

Academic Career Length

7Years (2020-Present)

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

Representative Publications

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Verified
Journal Article
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RDRomain Didier
Romain Didier
CBClément Benic
Clément Benic
BNBahaa Nasr
Bahaa Nasr
FVFlorent Le Ven
Florent Le Ven
SHSinda Hannachi
Sinda Hannachi
MGMartine Gilard
Martine Gilard
Mean Gradient (MG) elevation can be detected immediately after transcatheter aortic valve implantation (TAVI) or secondarily during follow-up. Comparisons and interactions between these two parameters and their impact on outcomes have not previously been investigated. This study aimed to identify incidence, influence on prognosis, and parameters associated with immediate high post-procedural mean transvalvular gradient (PPMG) and delayed mean gradient increase (6 to 12 months after TAVI, DMGI) in the FRANCE 2 (French Aortic National CoreValve and Edwards 2) registry. The registry includes all consecutive symptomatic patients with severe aortic stenosis who have undergone TAVI. Three groups were analyzed: (1) PPMG < 20 mmHg without DMGI > 10 mmHg (control); (2) PPMG < 20 mmHg with DMGI > 10 mmHg (Group 1); and (3) PPMG ≥ 20 mmHg (Group 2). From January 2010 to January 2012, 4201 consecutive patients were prospectively enrolled in the registry. Controls comprised 2078 patients. In Group 1(n = 131 patients), DMGI exceeded 10 mmHg in 5.6%, and was not associated with greater 4-years mortality than in controls (32.6% vs. 40.1%, p = 0.27). In Group 2 (n = 144 patients), PPMG was at least 20 mmHg in 6.1% and was associated with higher 4-year mortality (48.7% versus 40.1%, p = 0.005). A total of two-thirds of the patients with PPMG ≥ 20 mmHg had MG < 20 mmHg at 1 year, with mortality similar to the controls (39.2% vs. 40.1%, p = 0.73). Patients with PPMG > 20 mmHg 1 year post-TAVI had higher 4-years mortality than the general population of the registry, unlike patients with MG normalization.

23 October 2023 in Journal of Clinical Medicine
Verified
Journal Article
Open access
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CBClément Benic
Clément Benic
PNPierre Philippe Nicol
Pierre Philippe Nicol
SHSinda Hannachi
Sinda Hannachi
MGMartine Gilard
Martine Gilard
RDRomain Didier
Romain Didier
BNBahaa Nasr
Bahaa Nasr
TAVI requires a large-bore arteriotomy. Closure is usually performed by the suture system. Some studies report a vascular complication rate of up to 21%. MANTA is a recently developed percutaneous closure system dedicated to large caliber vessels based on an anchoring system. Early studies report a lower rate of vascular complications with MANTA devices. This single-center retrospective study included all patients who underwent femoral TAVI at the Brest University Hospital from 20 November 2019 to 31 March 2021. The primary endpoint is the rate of vascular complications (major and minor) pre and post-TAVI procedure. In total, 264 patients were included. There were no significant differences in vascular complications (major and minor) between the two groups (13.6% in the MANTA group versus 21.2% in the PROSTAR group; p = 0.105), although there was a tendency to have fewer minor vascular complications in the Manta group (12.1% versus 20.5%; p = 0.067). Manta was associated with a lower rate of bleeding complications (3.8% versus 15.2%; p = 0.002), predominantly minor complications with fewer closure failures (4.5% versus 13.6%; p = 0.01), less use of covered stents (4.5% versus 12.9%; p = 0.016), and with no difference in the need for vascular surgery compared to the Prostar group (1.5% versus 2.3%; p = 0.652). On the other hand, Manta was associated with a higher rate of femoral stenosis (4.5% versus 0%; p = 0.013) without clinical significance (1.5% versus 0%; p = 0.156). The Manta and Prostar devices are equivalent in terms of vascular complications. The Manta, compared to the Prostar, is associated with fewer bleeding complications.

26 March 2025 in Bioengineering
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Journal Article
Open access
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YBYahia BELLOUCHE
Yahia BELLOUCHE
SASirine Abdelli
Sirine Abdelli
SHSinda Hannachi
Sinda Hannachi
CBClément Benic
Clément Benic
FVFlorent Le Ven
Florent Le Ven
RDRomain Didier
Romain Didier
Aortic stenosis (AS) frequently coexists with coronary artery disease (CAD), complicating revascularization decisions. The use of coronary physiology indices, such as the fractional flow reserve (FFR), instantaneous wave-free ratio (iFR), and coronary flow reserve (CFR), in AS patients remains debated, particularly after transcatheter aortic valve implantation (TAVI). In this study, we employ computational fluid dynamics (CFD) to evaluate coronary hemodynamics and assess changes in the wall shear stress (WSS) before and after TAVI. Our analysis demonstrates strong agreement between CFD-derived and invasive FFR measurements, confirming CFD’s reliability as a non-invasive tool for coronary physiology assessment. Furthermore, our results show no significant changes in FFR (p=0.92), iFR (p=0.67), or CFR (p=0.34) post-TAVI, suggesting that these indices remain stable following aortic valve intervention. However, a significant reduction in high WSS exposure (59% to 40.8%, p<0.001) and the oscillatory shear index (OSI: 0.32 to 0.21, p<0.001) was observed, indicating improved hemodynamic stability. These findings suggest that coronary physiology indices remain reliable for revascularization guidance post-TAVI and highlight a potential beneficial effect of aortic stenosis treatment on plaque shear stress dynamics. Our study underscores the clinical utility of CFD modeling in CAD management, paving the way for further research into its prognostic implications.

9 May 2020 in The International Journal of Cardiovascular Imaging
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Journal Article
Closed access
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MMMohamad Mansour
Mohamad Mansour
JMJacques Mansourati
Jacques Mansourati
FVFlorent Le Ven
Florent Le Ven
RDRomain Didier
Romain Didier
MGMartine Gilard
Martine Gilard
YJYannick Jobic
Yannick Jobic

15 October 2025 in Journal of Clinical Medicine
Verified
Journal Article
Open access
PDF file
YBYahia BELLOUCHE
Yahia BELLOUCHE
CBClément Benic
Clément Benic
SHSinda Hannachi
Sinda Hannachi
PNPierre Phillipe Nicol
Pierre Phillipe Nicol
CJChristopher Jousse
Christopher Jousse
RDRomain Didier
Romain Didier
Background/Objectives: Coronary artery disease (CAD) remains the leading global cause of mortality, underscoring the need for functional assessments that extend beyond anatomical evaluation. The Hyperemic Stenosis Resistance (HSR) index combines invasive pressure and flow parameters to assess stenosis severity but faces limitations due to methodological and standardization challenges. This study aimed to introduce and validate a novel non-invasive computational equivalent of HSR (cHSR), derived from coronary computed tomography angiography (CCTA), and to compare its diagnostic performance with fractional flow reserve derived from computational fluid dynamics (FFRCFD) and quantitative flow ratio (QFR). Methods: A retrospective analysis was conducted on 64 patients (106 coronary lesions) with suspected chronic coronary syndrome (CCS) who underwent both CCTA and invasive coronary angiography (ICA). Computational simulations incorporated patient-specific boundary conditions based on CCTA-derived left ventricular and aortic flow data. Diagnostic accuracy for predicting revascularization was compared among cHSR, FFRCFD, and QFR. Results: FFRCFD showed a strong correlation with invasive FFR (r = 0.87, p < 0.0001). The cHSR index achieved the highest diagnostic accuracy (96.2%) at an optimal cut-off of 0.75 mmHg/cm·s−1, outperforming both FFRCFD and QFR. No significant correlation was found between cHSR and shear stress parameters, including the Oscillatory Shear Index (OSI) and Time-Averaged Wall Shear Stress (TAWSS), indicating complex hemodynamic interactions beyond simple flow–pressure relationships. Conclusions: The computational hyperemic stenosis resistance (cHSR) index represents a promising non-invasive tool for the functional assessment of CAD, demonstrating superior diagnostic performance compared with existing imaging-based indices. Prospective multicenter studies with larger populations are warranted to confirm its clinical applicability and prognostic value in chronic coronary syndrome management.