Introduction: Coronary shear stress (CSS) is a well-es-tablished local mechanical factor in atherogenesis, pro-gression and destabilization of atherosclerotic plaques. Analysis of CSS after coronary stent placement is still lacking of large clinical studies.
Objective: T he aim of this study was to: (1) test the feasibility of Coronary Computed Tomography Angi-ography (CCTA) for assessment of local hemodynamic and luminal changes after implantation of bioresorba-ble vascular scaffolds (BVS), and (2) to investigate CSS modifications after BVS implantation.
Methods: We conducted a single center, prospective pilot study on 73 patients with coronary artery disease who underwent elective percutaneous coronary inter-vention (PCI); group 1 (n=30) – patients with BVS and group 2 (n=43) – patients with bare metal stent (BMS) implanted. CCTA scanning was performed in all pati-ents prior PCI and at 12 months after PCI. The mean CSS at proximal and at distal part of the stented seg-ment and at the level of the minimal lumen area (MLA) was calculated at baseline and at 12 months after BVS placement.
Results: CCTA revealed a higher incidence of seve-re coronary stenosis in group 1 (73%) than in group 2 (30%) (p<0.0001). Sensibility of visual evaluation for identification of in-stent restenosis on CCTA was increased in BVS group (94%) than in BMS group (76.19%) (p=0.0006), hence the group 1 had lower in-cidence of non-diagnostic evaluations. Mean CSS at the stented site was significantly lower at 12 months (1.9 +/- 0.68 Pa) that average CSS at baseline (2.87 +/-3.08 PA) (p=0.0001). CSS analysis showed also a sig-nificantly decreased values at proximal level from 3.39 +/- 1.93 Pa at baseline to 1.91 +/- 0.68 Pa at follow up (p<0.0001), but not a significant decrease at distal part– 1.3 +/- 0.72 Pa at baseline and 1.59 +/- 0.65 Pa at 12 months follow up (p=0.9).
Conclusions: CCTA is a feasible technique for assess-ment of luminal changes following BVS implantation. BVS implantation contribute to the improvement of local hemodynamics by restoring physiological pattern of coronary flow, as demonstrated by the computatio-nal fluid hemodynamics assessment of coronary circu-lation.