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• Coronary pressure gradually decreased across the length of the left anterior descending artery (LAD) but not the right coronary artery (RCA). • The backward-traveling suction wave decreased through the length of the LAD. • The change in the backward suction wave correlated with myocardial territory size. • All wave intensity parameters were constant throughout the length of the RCA. This study evaluated the mechanism of decline in coronary pressure from the proximal to the distal part of the coronary arteries in the left anterior descending (LAD) versus the right coronary artery (RCA) from the insight of coronary hemodynamics using wave intensity analysis (WIA). Twelve patients with angiographically normal LAD and RCA were prospectively enrolled. Distal coronary pressure, mean aortic pressure, and average peak velocity were measured at 4 different positions: 9, 6, 3, and 0 cm distal from each coronary ostium. The distal-to-proximal coronary pressure ratio during maximum hyperemia gradually decreased in proportion to the distance from the ostium (0.92±0.03 and 0.98±0.03 at 9 cm distal to the LAD and RCA ostium). WIA showed the dominant forward-traveling compression wave gradually decreased and the backward-traveling suction wave gradually decreased in proportion to the decrease in coronary pressure through the length of the non-diseased LAD but not the RCA. The pushing wave and suction wave intensities on WIA were diminished in proportion to the distance from the ostium of the LAD despite the wave intensity not changing across the length of the RCA, which may lead to gradual intracoronary pressure drop in the angiographically normal LAD. [ABSTRACT FROM AUTHOR]

This study assessed the efficacy of the tip detection method during intravascular ultrasound (IVUS)–based 3-dimensional (3D) wiring with a new chronic total occlusion (CTO)–specific IVUS system (AnteOwl IVUS [AO-IVUS]) for CTO percutaneous coronary intervention (PCI). The study developed angiography-based 3D wiring for CTO-PCI. Previously, the authors produced a short-tip CTO-specific IVUS system (Navifocus WR IVUS [Navi-IVUS]), which has been upgraded into the AO-IVUS system by adding a pullback transducer system for IVUS-based 3D wiring. A CTO lesion 20 mm in length composed of 2.5% agar was experimentally inserted into the coronary artery of a beating heart model. The target (a microcatheter with a 0.6-mm lumen) was placed in the distal part of the CTO lesion. IVUS-guided wiring was performed to insert the guidewire into the target using the Navi-IVUS and then using the AO-IVUS 8 times each. In wiring with AO-IVUS, the IVUS-based 3D wiring using the tip detection method was performed. The crossing time and the number of punctures to the target were calculated. The crossing time was significantly shortened and the number of punctures was significantly reduced in AO-IVUS–based wiring compared with Navi-IVUS–based wiring (median crossing time 80.5 s [interquartile range: 44.0 to 112.3 s] vs. 333.0 s [interquartile range: 88.8 to 790.0 s]; p = 0.036; median 1.0 puncture [interquartile range: 1.0 to 2.0 punctures] vs. 24.0 punctures [interquartile range: 5.8 to 52.5 punctures]; p = 0.001). The tip detection method enables the authors to easily perform the IVUS-based 3D wiring, and the new CTO IVUS system will facilitate this method in clinical practice. [ABSTRACT FROM AUTHOR]

Background The optimal sizing of self-expanding paclitaxel-eluting stents (PES) in the treatment for superficial femoral artery (SFA) lesions is unclear. This study sought to investigate the influence of PES diameter on stent patency in SFA lesions using optical frequency domain imaging (OFDI). Methods A total of 20 de novo SFA lesions were randomized 1:1 to receive either self-expanding PES with a nominal diameter of 6 mm or 8 mm. Follow-up angiography and OFDI was scheduled six months after stent implantation, and volumetric OFDI analysis was performed to evaluate vascular response to the stents. Volume index (VI) was defined as the volume divided by the stent length. The primary end point was lumen VI at the 6-month follow-up. Secondary end point was minimum lumen diameter (MLD) by quantitative vascular angiography (QVA) at the follow-up. Results Stent length was 78.0 ± 23.9 mm in the 6-mm group and 70.0 ± 23.6 mm in the 8-mm group ( p = 0.46). Baseline QVA data were also similar between the two groups. MLD immediately after stent implantation was similar between the two groups (4.2 ± 0.5 mm in the 6-mm group and 3.9 ± 0.5 mm in the 8-mm group, p = NS). At the 6-month follow-up, MLD was greater in the 8-mm group compared to the 6-mm group (4.0 ± 1.0 mm vs. 3.2 ± 0.4 mm, p < 0.05). Stent VI was larger in the 8-mm group (28.4 ± 6.7 mm 3 /mm vs. 22.2 ± 1.2 mm 3 /mm, p = 0.01). Neointimal VI was similar between the two groups (5.8 ± 2.9 mm 3 /mm vs. 5.2 ± 2.6 mm 3 /mm, p = 0.68). Lumen VI was greater in the 8-mm group (23.2 ± 7.6 mm 3 /mm vs. 17.3 ± 2.6 mm 3 /mm, p = 0.04). Conclusions Chronic stent enlargement resulted in greater lumen area after implantation of self-expanding PES with a large diameter at the mid-term follow-up. Stent diameter might be important for stent patency in procedure with PES for SFA lesions. [ABSTRACT FROM AUTHOR]

Although spontaneous coronary artery dissection (SCAD) is usually diagnosed by coronary angiography, diagnosis may be missed because of various presentations and imperfections of coronary angiography. We report a case of a 41-year-old female with pregnancy-related SCAD who presented with cardiac arrest. Initial coronary angiography was normal without intimal flap. Unexpectedly, 4 days after admission, SCAD in left main trunk was revealed with recurrent myocardial infarction. Intimal flap was sealed at the time of first angiography and this is an interesting point that made us report this case. SCAD is a rare but not negligible cause of not only acute myocardial infarction but also sudden cardiac arrest even if first coronary angiography is normal. < Learning objective: In a case of a young post-partum woman with resuscitated sudden cardiac arrest who has normal coronary artery, intensive observation is needed. We should be aware that spontaneous coronary artery dissection is a rare but not negligible cause even if initial coronary angiography is normal.> [ABSTRACT FROM AUTHOR]

Postcatheterization pseudoaneurysm is one of the most common vascular complications of peripheral angiographic procedures. An 83-year-old male received endovascular treatment (EVT) for a total occlusion lesion of left superficial femoral artery (SFA) due to intermittent claudication. After the subintimal angioplasty procedure with implantation of three self-expandable nitinol stents, angiography revealed contrast staining outside the stent margins. Duplex ultrasonography immediately after the procedure confirmed a pseudoaneurysm of 12 mm in diameter. There was no change in the size of pseudoaneurysm during the follow-up period. Four years after the initial procedure, he was admitted to our hospital because of swelling and pain in his left thigh. The angiography showed stent fracture at the proximal shaft of the stent. Furthermore, a fractured fragment of the stent was lying within the ruptured pseudoaneurysm, and active extravasation of contrast medium was identified. Surgical repair of the pseudoaneurysm was performed. We report a case of spontaneous pseudoaneurysm rupture of the SFA that had developed because of subintimal stent placement 4 years previously. If pseudoaneurysm is confirmed after EVT with subintimal stent placement, it should be treated by surgical or percutaneous methods, regardless of its size. < Learning objective: In general, conservative observation is thought to be reasonable when the size of pseudoaneurysm is small (<20 mm) in the absence of severe pain. However, repair of pseudoaneurysm should be considered, when the pseudoaneurysm was caused by arterial wall rupture after subintimal stent placement for a totally occluded lesion of the superficial femoral artery. It has a higher risk of spontaneous rupture during the long-term period.> [ABSTRACT FROM AUTHOR]

Background Optical coherence tomography (OCT) is one of the tools trying to distinguish neoatherosclerosis from other neointimal tissue but its role has to be still validated. This study evaluated the diagnostic accuracy of OCT for characterization of lipid-atherosclerotic neointima following drug-eluting stent (DES) implantation. Methods Twelve stented coronary arteries from the 7 autopsy hearts were imaged by OCT. These OCT images were compared with histology. By OCT, the morphological appearances of neointima were classified into three patterns: homogeneous pattern, heterogeneous pattern with visible strut, or heterogeneous pattern with invisible strut. Results Of 21 histological cross-sections, 6 were categorized as homogeneous patterns (29%), 11 as heterogeneous patterns with visible stent strut (52%), and 4 as heterogeneous patterns with invisible stent strut (19%). All homogeneous patterns were composed of smooth muscle cells with collagen fibers. The heterogeneous patterns with visible stent strut included proteoglycan-rich myxomatous matrix and calcium deposition. On the other hand, the heterogeneous patterns with invisible stent strut comprised atheromatous tissue, including a large amount of foam cell accumulation (25%) or large fibroatheroma/necrotic core (75%) inside the stent struts within neointima. The optical attenuation coefficient was highest in the heterogeneous pattern with invisible stent strut due to scattering of light by atheromatous tissue. Conclusion The heterogeneous patterns with invisible stent strut on OCT imaging identify the presence of lipid-atherosclerotic tissue within neointima after DES. This may suggest the potential capability of OCT based on visualization of stent struts for discriminating atheromatous formation within neointima from other neointimal tissue. [ABSTRACT FROM AUTHOR]