Alexandru STAN

Alexandru STAN


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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11 September 2023 in Diagnostics
Verified
Journal Article
Open access
PDF file
ASAlexandru STAN
Alexandru STAN
PCPaul Calburean
Paul Calburean
DRDrincal Katalin Reka
Drincal Katalin Reka
MHMarius Harpa
Marius Harpa
AEAyman Elkahlout
Ayman Elkahlout
MMMarius Mărușteri
Marius Mărușteri
(1) Background: Although transcatheter aortic valve replacement (TAVR) significantly improves long-term outcomes of symptomatic severe aortic stenosis (AS) patients, long-term mortality rates are still high. The aim of our study was to identify potential inflammatory biomarkers with predictive capacity for post-TAVR adverse events from a wide panel of routine biomarkers by employing ML techniques. (2) Methods: All patients diagnosed with symptomatic severe AS and treated by TAVR since January 2016 in a tertiary center were included in the present study. Three separate analyses were performed: (a) using only inflammatory biomarkers, (b) using inflammatory biomarkers, age, creatinine, and left ventricular ejection fraction (LVEF), and (c) using all collected parameters. (3) Results: A total of 338 patients were included in the study, of which 56 (16.5%) patients died during follow-up. Inflammatory biomarkers assessed using ML techniques have predictive value for adverse events post-TAVR with an AUC-ROC of 0.743 and an AUC-PR of 0.329; most important variables were CRP, WBC count and Neu/Lym ratio. When adding age, creatinine and LVEF to inflammatory panel, the ML performance increased to an AUC-ROC of 0.860 and an AUC-PR of 0.574; even though LVEF was the most important predictor, inflammatory parameters retained their value. When using the entire dataset (inflammatory parameters and complete patient characteristics), the ML performance was the highest with an AUC-ROC of 0.916 and an AUC-PR of 0.676; in this setting, the CRP and Neu/Lym ratio were also among the most important predictors of events. (4) Conclusions: ML models identified the CRP, Neu/Lym ratio, WBC count and fibrinogen as important variables for adverse events post-TAVR.

HSHoratiu Suciu
Horatiu Suciu
AEAyman Elkahlout
Ayman Elkahlout
VNViorel Nicolae
Viorel Nicolae
FTFlavius Tomșa
Flavius Tomșa
ASAlexandru STAN
Alexandru STAN
MHMarius Harpa
Marius Harpa
Background: The aim of this study was to compare costs and clinical outcomes associated with transcatheter aortic valve implantation (TAVI) versus surgical aortic valve replacement (SAVR). A secondary analysis was performed in patients with coronary artery disease, and patients with TAVI and percutaneous coronary intervention (PCI) were compared with SAVR and coronary artery bypass grafting (CABG). Methods: All patients who underwent the TAVI or SAVR procedure for severe degenerative aortic stenosis between August 2013 and February 2025 at a tertiary cardiovascular center were selected for inclusion in the present study. Patients were excluded if there was no available follow-up or if there was a crossover between treatments (especially CABG undergoing TAVI or SAVR undergoing PCI within a 6-month timeframe). Results: A total of 2452 patients (1925 undergoing SAVR and 527 undergoing TAVI) were included. Of those, 400 underwent SAVR + CABG and 75 underwent TAVI + PCI. During a median follow-up of 2.88 (1.12–6.43) years, a total of 404 all-cause events occurred, corresponding to 4.18 deaths per 100 patient-years. TAVI was associated with higher hospitalization costs and fewer in-hospital deaths than SAVR. However, long-term survival was similar between TAVI and SAVR and between TAVI + PCI and SAVR + CABG. Interventional treatment was more cost-effective in patients with EuroSCORE > 10%, while surgical treatment was more cost-effective in patients with EuroSCORE < 10%. Conclusions: In patients who are at high surgical risk, TAVI is more cost-effective than SAVR, and TAVI + PCI is more cost-effective than SAVR + CABG. In patients who are not at high surgical risk, SAVR is more cost-effective than TAVI, and SAVR + CABG is more cost-effective than TAVI + PCI.

Verified
Journal Article
Open access
PDF file
ASAlexandru STAN
Alexandru STAN
AEAyman Elkahlout
Ayman Elkahlout
MHMarius Harpa
Marius Harpa
MPMarian Pop
Marian Pop
MVMihaly Veres
Mihaly Veres
HSHoratiu Suciu
Horatiu Suciu
The main objective of this study was to compare the long-term outcomes of transcatheter aortic valve implantation (TAVI) in patients with severe aortic stenosis, focusing on differences between self-expanding valve (SEV) versus balloon-expandable valve (BEV) prostheses and the influence of balloon pre- and post-dilatation on clinical results. The secondary objective was to report the long-term outcomes after TAVI in Romania. All patients who underwent a TAVI procedure for severe AS between November 2016 and May 2025 at a tertiary center in Romania were included in the present study. A total of 702 patients were included, of which 455 (64.8%) and 247 (35.1%) patients received a BEV (Sapien3 platform) and a SEV (Accurate, Boston, Portico, Evolut, or Navitor platforms), respectively. Pre-dilatation was performed in 514 (73.2%) cases, and post-dilatation was performed in 189 (26.9%) cases. There were 10.5 and 7.8 all-cause and cardiovascular-cause mortality event rates per 100 patient years, respectively. In regard to the univariable Cox regression, a BEV has significantly lower mortality than an SEV (HR = 0.67[0.46–0.96], p = 0.03), pre-dilatation did not influence mortality (HR = 0.71[0.48–1.04], p = 0.08), and post-dilatation significantly increased mortality (HR = 1.51[1.05–2.19], p = 0.03). In regard to the multivariable Cox regression, survival was not influenced by pre-dilatation or the valve platform, while post-dilatation had a trend towards higher mortality (p = 0.06). The BEV and SEV have similar survival rates, with no heterogeneity among a large number of TAVI platforms. While pre-dilatation had no impact on mortality, post-dilatation was associated with a trend towards increased mortality (p = 0.06), which was independent of the transprosthetic gradient. Survival after TAVI in Romania is comparable to that reported in Western registries.