Yasuhiro Nagayoshi

Contrast Injection Protocols for Coronary Computed Tomography Angiography Using a 64-Detector Scanner : Comparison Between Patient Weight-Adjusted-and Fixed Iodine-Dose Protocols

Objective:To compare patient-weight-adjusted and fixed iodine-dose protocols at coronary computed tomography angiography (CTA) using a 64-detector scanner and computer-assisted bolus tracking. Materials and Methods:Approval from our institutional review board and patient prior informed consent were obtained before entering 60 patients with suspected coronary disease in this study. The patients were randomly assigned to one of 2 protocols. In the fixed iodine-dose protocol, they received a fixed dose of 80 mL Iopamidol-370; the injection duration was 20 seconds. In the weight-adjusted iodine-dose protocol, the dose was tailored to the patient body weight; this group received 1.0 mL/kg and the injection duration was shorter, ie, 15 seconds. Imaging was on a 64-detector CT scanner using a computer-assisted bolus tracking technique. A radiologist blinded to the protocol used measured the Hounsfield density number of the large vessels and coronary arteries. CT attenuation in the aortic root was compared in patients whose weight was less than 58 kg (group 1) or 58 kg or more (group 2). The standard deviation (SD) of CT attenuation in the aortic root and the myocardium was compared with evaluate image noise. Using a 3-point scale, 2 radiologists independently evaluated beam-hardening artifacts and coronary enhancement. Statistical analysis was with the two-tailed Student t test and the Mann-Whitney U test. Results:There was no significant difference between the protocols with respect to CT attenuation of the ascending aorta and coronary arteries. Under the fixed-iodine-dose protocol, mean CT attenuation in the aortic root was 421.3 ± 51.5 Hounsfield unit (HU) in the lighter-, and 397.2 ± 42.3 HU in the heavier weight group, respectively; the difference was statistically significant (P = 0.03). Under the weight-adjusted iodine-dose protocol, these values were 407.6 ± 85.1 and 409.2 ± 47.9 HU, respectively and the difference was not statistically significant (P = 0.17). The SD of the ascending aorta and myocardium was significantly higher for the fixed- than the weight-adjusted iodine-dose protocol. The mean visual score for beam-hardening artifacts was significantly lower in the weight-adjusted- than the fixed-iodine-dose protocol (P < 0.01), however, there was no significant difference in the enhancement of the coronary arteries (P = 0.82). Conclusion:At 64-detector CTA of the heart, the patient weight-tailored dose protocol with the 15-second injection duration yielded significantly better image quality than the fixed-dose, 20-second injection duration protocol.

Coronary artery bypass grafting in octogenarians

Preoperative profiles, postoperative complications, and the early and late results in 32 patients 80 yrs. of age and older (elderly group) who underwent coronary artery bypass grafting were compared with those in patients under 80 yrs. of age (control group). In the elderly group, the prevalence of patients with preoperative creatinine clearance (Ccr.) <50 l/day (34.4%), unstable angina pectoris (78.1%) and left main trunk disease (40.1%) was significantly higher than those in the control group. The incidences of arrhythmia and intensive care unit(ICU) syndrome were also significantly higher in the elderly group than in the control group, however, there was no death due to these complications. In the elderly group, one patient (3.1%) died in the hospital due to low cardiac output syndrome (LOS), while three patients (2.4%) of the control group died in the hospital. As for the long-term results, the 5-yr. survival rates for the elderly group and the control group were 82.6% and 85.2%, respectively, and the effectiveness of surgery was remarkable, with improved postoperative activity in 96.9% of the elderly group. These findings indicate that although the elderly patients have higher risks by undergoing surgery and have a disadvantage in the rate of postoperative complications, the postoperative improvement in activity and survival rate can be similar to those in the younger patients.

Successful surgical treatment of an infrarenal abdominal pseudoaneurysm caused by tuberculosis: Report of a case

A 76-year-old man was admitted to our hospital for investigation of an apparent abdominal aortic aneurysm detected during treatment for epididymitis. A chest X-ray showed miliary shadows in the bilateral lung fields strongly suggestive of tuberculosis. The diameter of the aneurysm increased, and examinations showed impending rupture of a pseudoaneurysm. However, a definitive disease pathogenesis was not obtained before surgery. We performed a subemergency operation, which revealed an infrarenal abdominal pseudoaneurysm caused by tuberculosis. The pseudoaneurysm appeared to have resulted from direct extension of tuberculous lymphadenitis to the aortic wall, which ruptured. We review 24 other cases of tuberculous aortic aneurysms surgically treated in Japan before 2004.

Dose-dependent INhibitory effect of rosuVastatin In Japanese patienTs with Acute myocardial infarcTION on serum concentration of matrix metalloproteinases – INVITATION trial

BACKGROUND Acute myocardial infarction (AMI) is mainly characterized by the rupture of lipid-rich vulnerable atherosclerotic plaque. The matrix metalloproteinases (MMPs) have been shown to play a critical role in inflammatory processes underlying plaque rupture. Some reports suggested statins inhibit the increased MMP levels after AMI. However, there are a few comparison studies between the different dosages of the same statin and circulating levels of MMPs. PURPOSE This study will preliminarily investigate the potential effects of appropriate or low dose of rosuvastatin on circulating MMPs levels in AMI patients. Moreover, we will also obtain plasma from patients while undergoing diagnostic angiography to determine differences in various cardiac sites and peripheral vessels. METHODS This study is a multicenter, open-label, randomized, parallel-group study to be conducted to compare the appropriate or low dose of rosuvastatin in the effect on serum levels of inflammatory markers in AMI patients. The eligible patients undergoing percutaneous coronary intervention (PCI) will be randomly assigned to receive either appropriate or low-dose rosuvastatin daily using a web-based randomization software within 24h after PCI. The low-dose group will be treated with rosuvastatin 2.5mg once daily with a follow-up. The appropriate-dose group will begin treatment with rosuvastatin 5mg once daily, and the dose of rosuvastatin will be titrated to 10mg within 4 weeks. During administration of the study treatment, subjects will undergo laboratory testing including MMPs and be monitored for the occurrence of adverse events up to 24 weeks. The primary endpoint will be the change rate of MMPs at 24 weeks after administration. CONCLUSIONS INVITATION will compare the appropriate or low dose of rosuvastatin in the effects on serum levels of inflammatory markers including MMPs in AMI patients. This study will provide significant information on rosuvastatin as an anti-inflammatory agent for AMI.

Response to Pollari et al. re: “Clinical Impact of Telemedicine Network System at Rural Hospitals Without On-Site Cardiac Surgery Backup”

W e thank Pollari et al. for their comments on our recent article. We also greatly appreciate their attempt to conduct a pioneering experiment in cross-border telemedicine between major cities. Telecardiology has developed in various fields, including tele-echocardiography, tele-electrocardiography, and telemonitoring of vital information in patients with acute coronary syndrome and heart failure. Emergent consultation using teleangiography is one of the features of the Kumamoto telemedicine network. At any time, physicians can consult experts in high-volume centers about emergent cases such as left main coronary artery disease associated with acute coronary syndrome. In contrast, our network has not yet been fully utilized for elective surgery. There are several factors that may be involved here. First, cardiologists play a leading role in our network utilization. In Japan, percutaneous catheter intervention can be performed in each medical service area. Teleconsultation is usually performed when the treatment capacity available in a facility is exceeded. This is one of the reasons why the system utilization is different among facilities. Second, the Ministry of Health, Labor and Welfare requires that treatment be given face-to-face in Japan. Telemedicine is limited to patients with chronic disease who live in remote areas. In our network, doctors receive no fee under the public health insurance system. Policy promotion is necessary for the expansion of telemedicine in Japan. Finally, the difficulty of risk stratification of elderly people is an important problem. In recent years, an increasing number of elderly individuals are undergoing cardiac surgery. Although EuroSCORE is a proven predictor of operative mortality, both physical frailties and cognitive impairments of patients are not fully reflected in this score. Pollari et al. use videoconferencing for evaluation of the general status of patients. Videoconferencing is expected to be used as a substitute for a face-to-face meeting. Unfortunately, the use of videoconferencing is limited in Japan for the reasons already listed. Telemedicine for surgical cardiology is a developing area. There is not sufficient evidence to disseminate the system widely. We are hopeful that Pollari et al. will achieve success in this area.

HEART ATTACKS TRIGGERED BY HUGE MUD SLIDES IN MOUNTAIN REGIONS AND SEVERE FLOODING IN INHABITED AREAS

On July 12, 2012, heavy rains struck southwest Japan, particularly in Mount Aso area, where approximately 30,000 people inhabited. Huge mud slides in the mountains destroyed houses. Clinical impact of heavy rain and flooding on the occurrence of cardiovascular events remains unknown. We investigated

Reactivity of the Internal Thoracic Artery Graft to Drugs in Coronary Artery Bypass Grafting.

冠動脈バイパス術(CABG)において,われわれは左内胸動脈(LITA)採取時にphosphodiesterase III (PDE III)阻害剤をLITAへ直接注入し拡張させ,攣縮を予防することで血流量を増加させるよう,工夫している.今回,PDE III阻害剤とともに,塩酸パパベリン,硝酸イソソルビド(ISDN)を用い,LITAの薬剤反応性について比較検討した.CABG 42例を対象とし,各薬剤14例において薬剤投与前後のgraft free flow (GFF)と体血圧を計測し,血管抵抗(R)値を算出した.各薬剤でGFFIは有意に増加し,R値,体血圧は有意に低下した.いっぽう,各薬剤間の体血圧変化率に有意差はなく,PDE III阻害剤はほかの薬剤よりGFF変化率が有意に増加し,R値変化率が有意に低下した.この結果より,動脈グラフトの血流量増加にPDE III阻害剤はより有用であることが示唆された.