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Aims: The left coronary anomalous origin from the opposite sinus (L- ACAOS) constitutes the most clinically relevant arterial abnormality among the wide spectrum of coronary artery anomalies. We investigated the physiology of L-ACAOS with and without intramural course (IM) in athletes, using the computational fluid dynamic (CFD) analysis.Methods and Results: The coronary artery circulation with L-ACAOS with and without IM has been segmented and then reconstructed, after reviewing both the angiographic and computed tomography findings of 13 consecutive athletes (10 males, mean age 45.1 ± 8.2 years) with L-ACAOS collected in our institution between 1st January 2003 and 1st January 2018. Vorticity magnitude, static pressure and wall shear stress (WSS) have been analysed in a model of L-ACAOS with no IM course and in L-ACAOS-IM at rest and during exercise. The mean vorticity magnitude and WSS significantly increased from rest to exercise in both models, in right coronary artery, left anterior descending and left circumflex coronary arteries. The mean static pressure significantly increased with exercise in IM (1.118e + 004 vs 1.164e + 004 Pa, p < 0.001) as well as the mean vorticity magnitude and the mean WSS (7012.78 1/s vs 9019.56 1/s, p < 0.001, Δ = 2006.78 1/s and 3.02 Pa vs 2.11 Pa, p < 0.001, Δ = 0.91 Pa). This net increment was transmitted to the entire left coronary system in L-ACAOS-IM but not in L-ACAOS with no IM.Conclusions: In L-ACAOS, different hemodynamic parameters observed in the intramural segment seem to confirm that IM is compressed during exercise. These rheological properties might propagated along the left coronary system, potentially predisposing, if confirmed in vivo, distal coronary segments to a higher risk of spasm and thrombosis in athletes. [ABSTRACT FROM AUTHOR]

Background/purpose: Multiple BRSs and specifically the Absorb scaffold (BVS) (Abbott Vascular, Santa Clara, CA USA) have been often used to treat long diffuse coronary artery lesions. We evaluate by a computational fluid dynamic(CFD) study the impact on the intravascular fluid rheology on multiple bioabsorbable scaffolds (BRS) by standard overlapping versus edge-to-edge technique.Methods/materials: We simulated the treatment of a real long significant coronary lesion (>70% luminal narrowing) involving the left anterior descending artery (LAD) treated with a standard or edge-to-edge technique, respectively. Simulations were performed after BVS implantations in two different conditions: 1) Edge-to-edge technique, where the scaffolds are kissed but not overlapped resulting in a luminal encroachment of 0.015cm (150μm); 2) Standard overlapping, where the scaffolds are overlapped resulting in a luminal encroachment of 0.030cm (300μm). After positioning the BVS across the long lesion, the implantation procedure was performed in-silico following all the usual procedural steps.Results: Analysis of the wall shear stress (WSS) suggested that at the vessel wall level the WSS were lower in the overlapping zones overlapping compared to the edge-to-edge zone (∆=0.061Pa, p=0.01). At the struts level the difference between the two WSS was more striking (∆=1.065e-004 p=0.01) favouring the edge-to-edge zone.Conclusions: Our study suggested that at both vessel wall and scaffold struts levels, there was lowering WSS when multiple BVS were implanted with the standard overlapping technique compared to the "edge-to-edge" technique. This lower WSS might represent a substrate for restenosis, early and late BVS thrombosis, potentially explaining at least in part the recent evidences of devices poor performance. [ABSTRACT FROM AUTHOR]

Background: FFR is useful in defining the physiological significance of intermediate coronary stenosis and requires induction of maximal hyperemia and measurement of pressure proximal and distal to the stenosis. Hyperemia normally is induced by either IV or IC adenosine, a medication associated with short-term side effects. IV regadenoson and IC nitroprusside have been suggested as viable alternatives. This meta-analysis aims to identify all studies comparing use of intravenous (IV) regadenoson or intracoronary (IC) nitroprusside with IV adenosine to determine differences related to the agent utilized for assessment of fractional flow reserve (FFR).Methods: We searched PubMed, EMBASE, Web of Science, SCOPUS, ClinicalTrials.gov and the Cochrane Library databases for studies comparing IV regadenoson or IC nitroprusside to IV adenosine for FFR assessment. The main outcome was difference in mean FFR measurement. The main secondary outcomes were composite side-effect profile and reclassification of lesions.Results: Seven studies were included in the analysis, with a total of 375 patients. Compared to IV adenosine, there was no difference in the mean FFR derived from IV regadenoson (p=1.0) or IC nitroprusside (p=0.48). IV regadenoson was associated with 53% lower risk of pooled side effects compared to IV adenosine (p=0.05). IC nitroprusside was associated with 97% lower risk of pooled side effects compared to IV adenosine (p<0.001).Conclusions: IV regadenoson and IC nitroprusside produce similar pressure-derived FFR measurements compared to IV adenosine and have a favorable side effect profile. Both can be considered as alternative agents to IV adenosine for FFR measurement. Further clinical validation is warranted. [ABSTRACT FROM AUTHOR]

Background/purpose: Computational fluid dynamics (CFD) have been recently adopted in many fields of cardiovascular medicine and in interventional cardiology. Using CFD analysis we compared the use of different PCI procedures, with and without the utilization of a proximal optimization technique (POT), on a complex coronary artery bifurcation.Methods/materials: For the analysis, we considered a hypothetic model of a left anterior descending artery-diagonal Medina 1,1,1 bifurcation type with a diameter of the proximal main branch (MB) and the side branch (SB) set at 3.5mm and 2.5mm, respectively. The bifurcation angle has been set to 50°. For the stent simulation, we reconstructed a third-generation, ultra-thin strut everolimus-eluting stent (ORSIRO stent, Biotronik IC, Bulack, Switzerland).Results: The Nano-crush and the modified T techniques seem able to restore the most physiologic fluid dynamic profile. Conversely, the DK-crush and the culotte demonstrated an intermediate and worst effect, respectively. The addition of a final POT resulted favorably for both Nano-crush and reverse modified T techniques, whereas a neutral and lack of significant effects have been observed for the DK-crush and culotte technique, respectively.Conclusion: Different double-stenting techniques (DST) have a different impact on coronary flow physiology. Both Nano-crush and modified T techniques achieved the most physiologic profile. The addition of a final POT appears to be a favourable step for both Nano-crush and modified T. [ABSTRACT FROM AUTHOR]