Eiji Taguchi

Impact of shear stress and atherosclerosis on entrance-tear formation in patients with acute aortic syndromes

Weak aortic media layers can lead to intimal tear (IT) in patients with overt aortic dissection (AD), and aortic plaque rupture is thought to progress to penetrating atherosclerotic ulcer (PAU) with intramural hematoma (IMH). However, the influences of shear stress and atherosclerosis on IT and PAU have not been fully examined. Ninety-eight patients with overt AD and 30 patients with IMH and PAU admitted to our hospital from 2002 to 2007 were enrolled. The greater curvatures of the aorta, including the anterior and right portions of the ascending aorta and anterior portion of the aortic arch, were defined as sites of high shear stress. The other portions of the aorta were defined as sites of low shear stress based on anatomic and hydrodynamic theories. Aortic calcified points (ACPs) were manually counted on computed tomography slices of the whole aorta every 10 mm from the top of the arch to the abdominal bifurcation point. IT was more often observed at sites of high shear stress in overt AD than in PAU (73.5 vs 20.0 %, P < 0.0001). Significantly more ACPs were present in PAU than in overt AD (18.6 ± 8 vs 13.3 ± 10, P = 0.007). The present study suggests that high shear stress and less severe atherosclerosis could induce the occurrence of an IT, thereafter progressing to overt AD, and that low shear stress and more severe atherosclerosis could proceed to PAU with IMH. These findings may help to identify the entrance-tear site.

A lotus root-like appearance in both the left anterior descending and right coronary arteries

A 60-year-old man was referred to our hospital because of dyspnea on exertion. He was diagnosed with heart failure due to an old myocardial infarction. Myocardial stress perfusion scintigraphy revealed inducible myocardial ischemia. Coronary angiography revealed hazy slit lesions in both the left anterior descending (LAD) and right coronary arteries (RCA). We first performed percutaneous coronary intervention (PCI) on the LAD lesion. Subsequently, we performed PCI for the RCA lesion using multiple imaging modalities. We observed a lotus root-like appearance in both the LAD and RCA, and PCI was successful for both vessels. We describe this rare case in detail.

Resting angina due to papillary fibroelastoma of the right coronary cusp

A 63-year-old man with chest pain at rest was referred to our hospital. Transthoracic echocardiography showed a mobile ball-like mass at the top of the right coronary cusp. Subsequently, transesophageal echocardiography also showed a mobile mass at the right coronary cusp. Aortic valve replacement with a mechanical valve was performed under general anesthesia. We diagnosed this condition as papillary fibroelastoma based upon the pathological findings with hematoxylin and eosin staining, and Elastica van Gieson staining. Coronary angiography revealed no organic lesions. The operation was successful, and the patient remains asymptomatic. We speculate that the resting chest pain was induced by transient occlusion of the right coronary orifice by the tumor. We describe this rare case in detail including a review of the literature.

Inadvertent coronary endarterectomy during aspiration thrombectomy with a Thrombuster III GR catheter in a patient with acute coronary syndrome

We describe a 41-year-old woman who presented with acute ST-segment elevation myocardial infarction. Emergent percutaneous intervention was performed with aspiration thrombectomy followed by coronary artery stenting. White material was extracted from the aspiration catheter. Reperfusion therapy after stenting was successful. After undergoing a cardiac rehabilitation program, she was discharged from hospital on day 10. Pathological examination revealed that the aspirated material consisted of normal vascular components including endothelial and smooth muscle cells. Aspiration thrombectomy is a commonly used procedure with a low complication rate. This case presents the previously unreported complication of coronary artery injury.

Inferior Vena Cava Thrombi Caused by Enlarged, Solitary Hepatic Cyst

emia (2.5 g/dL; normal, >4.1 g/dL), mildly elevated creatinine (0.95 mg/dL; normal, <0.8 mg/dL), markedly elevated D-dimer (6.3 μg/mL; normal, <1.0 μg/mL), elevated fibrinogen, and fibrin degradation products (FDP; 17.1 μg/mL; normal, <5 μg/mL). Enhanced computed tomography (CT) showed a large hepatic cyst causing compression of the A n 80-year-old woman was referred to hospital due to worsening bilateral pedal edema and mild exertional dyspnea. Physical examination indicated pallor, bilateral pedal edema and a distended abdomen. A non-tender, firm, immobile mass was palpable in the right hypochondrium. Laboratory data indicated hypoalbumin-

Accuracy and usefulness of noninvasive fractional flow reserve from computed tomographic coronary angiography: comparison with myocardial perfusion imaging, echocardiographic coronary flow reserve, and invasive fractional flow reserve.

We present a case of coronary artery disease with intermediate stenosis in the proximal left anterior descending artery, which was evaluated using multiple functional modalities. FFRCT demonstrated a significant perfusion abnormality in the LAD, and the value of FFRCT (0.68) was similar to the value measured by invasive FFR (0.67). However, the other modalities gave discrepant results. In particular, perfusion scintigraphy with thallium showed no evidence of an inducible perfusion abnormality in the LAD territory. The patient was treated by PCI for two tandem lesions in the LAD. FFRCT may have potential as a default noninvasive method for assessment of coronary anatomy and physiology.

Two-step approach to avoid obstruction of the coronary ostium during transcatheter aortic valve implantation with the SAPIEN 3

Coronary obstruction during transcatheter aortic valve implantation (TAVI) is a rare complication, but it can be serious and is associated with a high mortality rate. This adverse event can be related to procedural factors or anatomic features [1]. Most commonly, the left main coronary artery is involved; however, obstruction of the ostium of the right coronary artery (RCA) might occur if a calcified leaflet is displaced over the ostium [2, 3]. In this case report, we describe a patient who had RCA obstruction during TAVI. The case was a 90-year-old female with symptomatic critical aortic stenosis (peak velocity of 5.9 m/s, aortic valve area of 0.35 cm2 and a mean gradient of 88 mmHg), a reduced left ventricular ejection fraction (42%), no significant coronary artery disease and a Society of Thoracic Surgeons score of 7.3%. The following measurements were obtained from preoperative computed tomography (CT): aortic valve annulus diameters of 26 mm (major) and 20 mm (minor); leaflet lengths of 11.2 mm (right), 11.2 mm (noncoronary) and 13.7 mm (left); very small sinus of valsalva (SOV) diameter (23 mm) (Fig. 1b) for the RCA and 27.4 mm for the left coronary; and severe bulky calcification (Fig. 1a, c, d) at the edge of the right coronary cusp. The ratio of leaflet length/coronary height at the right coronary cusp was 0.99. We used a 2-step approach to protect the RCA, because of the bulky calcified leaflet at the right coronary cusp and the small SOV. As the first step, we inserted a wire and balloon to the mid-portion of the RCA (Fig. 1e) before balloon aortic valvuloplasty (BAV) with a 20-mm balloon. After that, we performed balloon dilatation at the ostium of the RCA. Fortunately, cusp blockage was not observed immediately after balloon deflation. The first step may not necessarily be needed in all cases. However, we are concerned about cusp blockage after valvuloplasty. Only wire and/or balloon protection might be needed and not balloon dilatation. As the second step, we performed stent-set up (Fig. 1f) before TAVI with a 23-mm SAPIEN 3 (Edwards Lifesciences, Irvine, CA, USA). Immediately after valve deployment, there were no ST-segment changes; however, she had ventricular fibrillation that required two defibrillation shocks. A repeat aortogram showed no flow in the RCA secondary to ostial occlusion (Fig. 1g). Percutaneous coronary intervention (PCI) was performed immediately at the ostium of the RCA using the set-up stent with high radial force (BMX-J 3.5 × 18 mm, Terumo, Tokyo, Japan) (Fig. 1h), and the obstruction was eliminated. We performed CT on postoperative day 9, and it showed that the bulky calcification (dotted red circle) between the coronary stent and THV (blue asterisks) was sealed (Fig. 1i). Blue arrow indicates the site of coronary ostium. She was discharged 14 days after the procedure. At 1 year of follow-up, the patient had no symptoms of ischemia, and her functional status and cardiac performance had improved significantly. In conclusion, in this case at very high risk of coronary obstruction, coronary protection using a 2-step approach was helpful and effective to avoid a catastrophic complication.

Inadvertent consequences of percutaneous coronary intervention to treat unstable spontaneous coronary artery dissection

We present two cases of spontaneous coronary artery dissection (SCAD), which were diagnosed and treated with emergent percutaneous coronary intervention (PCI). Patients with ongoing ischemia due to SCAD need emergent coronary revascularization with PCI or coronary artery bypass grafting. We discuss the difficulties of PCI to bail out unstable SCAD regardless of the modern techniques and modalities. Brief reviews of the literature with relevance are included. <Learning objective: We should probably pay more careful attention to perform PCI for unstable SCAD because of the fragileness of the dissected vessels.>.