Takuji Katayama

Diagnostic accuracy of supine and prone thallium-201 stress myocardial perfusion single-photon emission computed tomography to detect coronary artery disease in inferior wall of left ventricle

ObjectiveProne thallium-201 (201Tl) myocardial perfusion single-photon emission computed tomography (SPECT) reduces false-positive rates when evaluating inferior wall abnormalities by minimizing diaphragmatic attenuation. The present study investigates the diagnostic validity of prone 201Tl stress myocardial perfusion SPECT for detecting coronary artery disease in the inferior wall of the left ventricle in Japanese patients.MethodsOf the 104 consecutive patients who underwent 201Tl stress myocardial perfusion SPECT to diagnose coronary artery disease, we evaluated 46 who underwent image acquisition in both the supine and prone positions, and coronary angiography within 3 months thereafter. Images were acquired in the routine supine position immediately following 201Tl (111 MBq) injection and 4 h following early acquisition. Images were acquired in the prone position only during the early phase following supine acquisition. We evaluated the SPECT images of the inferior half segments of the left ventricle using a five-point defect scoring system. According to the coronary angiographic findings, we investigated the diagnostic accuracy of stress-rest supine, stress supine, stress prone, and combined supine-prone images. Reduced uptake in the stress supine image of the combined images was considered as attenuation when uptake was normal in the prone image.ResultsThe sensitivity of the stress-rest supine, stress supine, stress prone, and stress-combined supine-prone images was 77%, 86%, 55%, and 55%, and the specificity was 71%, 54%, 79%, and 83%, respectively. Diagnostic accuracy was the highest in stress-rest supine images.ConclusionsProne images tended to improve the specificity of detecting coronary artery disease in the inferior wall, but not diagnostic accuracy compared with stress-rest supine images because of decreased sensitivity.

Cardiovascular and bleeding risk of non-cardiac surgery in patients on antiplatelet therapy.

BACKGROUND The perioperative risk of non-cardiac surgery (NCS) in the patients on antiplatelet therapy after percutaneous coronary intervention (PCI) remains unclear. METHODS This study was a retrospective and single center study. Between January 2008 and December 2011, 198 patients who had already received PCI underwent NCS in our hospital. Among them, 63 patients underwent surgery on dual antiplatelet therapy (DAPT group) and 88 patients on single antiplatelet therapy (SAPT group). We compared bleeding events and cardiovascular events during perioperative period between the two groups. RESULTS There was no stent thrombosis in either group. The bleeding events in the DAPT group were significantly higher than that in the SAPT group (9.5% vs 2.3%, p=0.049). There was no difference in events between with or without heparin-bridge in the SAPT group. CONCLUSIONS The frequency of bleeding events was higher in the DAPT group. Both bleeding and cardiovascular events with aspirin alone were low in our study. It may be safe to undergo NCS with SAPT after PCI.

Noninvasive tissue characterization of coronary arterial plaque by 16-slice computed tomography in acute coronary syndrome

Noninvasive characterization of coronary plaques is challenging for cardiologists. The authors’ goal was to explore the clinical feasibility of newly developed 16-slice computed tomography (CT) in tissue characterization of coronary arterial plaques in patients with acute coronary syndrome. Sixteen patients with acute coronary syndrome underwent 16-slice CT (Aquillion, Toshiba) and coronary arteriography with intravascular ultrasound (IVUS) within 7 days. Twenty-three plaques were classified by IVUS according to plaque echogenicity: 6 soft plaques, 11 intermediate plaques, and 6 calcified plaques. Mean (±SD) CT numbers (Hounsfield units [HU]) of these 3 types of plaques were 50.6 ±14.8 HU, 131 ±21.0 HU, and 721 ±231 HU, respectively. Sixteen-slice CT facilitates noninvasive tissue characterization of coronary arterial plaques.

A new form of retinopathy associated with myocardial infarction treated with percutaneous coronary intervention

Aim: To report a new form of retinopathy that was observed in patients who had undergone percutaneous coronary intervention (PCI) following acute myocardial infarction (AMI). Methods: Serial ophthalmological examinations were conducted in 40 patients who underwent PCI. Thirty patients were diagnosed with AMI, and another 10 had stable angina pectoris. Results: Cotton wool spots developed in 17 (57%) patients from the group with AMI undergoing PCI (n = 30) within 2 months. Of these, 41% (seven patients) also developed superficial haemorrhages. Retinopathy was most prominent 1–2 months after AMI and then tended to become quiescent afterwards, without treatment. Conclusion: We have identified a new form of retinopathy in patients with AMI that spontaneously subsides without treatment.

Coronary thrombus aspiration revealed tumorous embolism of myxofibrosarcoma from the left atrium

Thrombus aspiration is currently the standard strategy for primary PCI. Thrombus can be aspirated via aspiration catheters, restoring coronary blood flow. However, there are a limited number of reports regarding thrombus aspiration toward tumor embolized occlusion. We present a case of 90-year-old male with AMI caused by the metastatic tumor embolism. Emergent coronary angiography revealed total occlusion in three epicardial vessels. Histopathological examination of the aspirated specimen revealed the mixture of thrombus and metastatic tumor cells. Thrombus aspiration was partially effective for restoring coronary blood flow; however, it was very helpful for the final diagnosis of tumor embolism.

Ruptured saphenous vein graft pseudoaneurysm successfully treated with covered stents

Saphenous vein graft (SVG) pseudoaneurysms are rare complications following coronary bypass graft surgery. A 46-year-old man presented with streptococcal infectious endocarditis and needed sequential operations for aortic root reconstruction. Shortly after the surgeries, a composite SVG on the right coronary artery developed a ruptured pseudoaneurysm, which was successfully treated using covered stents.