奥村 雅徳

Background: The incidence, risk factors, and outcome of contrast-induced acute kidney injury (CI-AKI) in 730 patients with acute coronary syndrome (ACS) undergoing emergency percutaneous coronary intervention (PCI), whose contrast volume was below maximum allowable contrast dose (MACD) was prospectively investigated. Methods and Results: MACD was defined as (5 mlxbody weight [kW/baseline creatinine [mg/dl]). CI-AKI was defined as a greater than 25% increase in creatinine from the baseline or an absolute increase of >= 0.5 mg/dl within 48 h after the procedure. CI-AKI occurred in 212 (29%) patients. Patients with CI-AKI had a higher risk for in-hospital mortality (9.4% vs. 1.5%, P<0.001) and a longer stay in the coronary care unit (median, 4.0 vs. 3.0 days, P<0.001) compared with those without CI-AKI. In a multivariate logistic analysis including 20 clinical variables, elevated glucose levels as variables categorized into quartiles were independently (P<0.001) associated with the development of CI-AKI. In addition, this relationship was seen in both the subgroup of patients with known diabetes and that of those without known diabetes. Conclusions: CI-AKI might occur commonly and could be be associated with a more complicated clinical course in ACS patients undergoing emergency PCI whose contrast volume does not exceed MACD. Elevated pre-procedural glucose might be a powerful and independent risk factor for the development of CI-AKI in this population. (Circ J 2012; 76: 1848-1855)

Objective: High-mobility group box 1 (HMGB1) is a damage-associated molecular pattern molecule, which suggests a potential role of this protein in the pathophysiology of acute coronary syndrome (ACS). Circulating HMGB1 has been shown to be independently associated with cardiac mortality in ST-segment elevation myocardial infarction. However, its prognostic value remains unclear in unstable angina and non-ST-segment elevation myocardial infarction (UA/NSTEMI). Methods: HMGB1, high-sensitivity C-reactive protein (hsCRP), cardiac troponin I and B-type natriuretic peptide concentrations were measured on admission in 258 consecutive patients (mean age of 67 years) hospitalized for UA/NSTEMI within 24 h (mean, 7.4 h) of the onset of chest symptoms. Results: A total of 38 (14.7%) cardiovascular deaths, including 10 in-hospital deaths, occurred during a median follow-up period of 49 months after admission. In a stepwise Cox regression analysis including 19 well-known clinical predictors of ACS, HMGB1 [relative risk (RR) 3.24 per 10-fold increment; P = 0.0003], cardiac troponin I (RR 1.83 per 10-fold increment, P = 0.0007), Killip class > 1 (RR 4.67, P = 0.0001) and age (RR 1.05 per 1-year increment, P = 0.03), but not hsCRP, were independently associated with cardiovascular mortality. In-hospital and cardiovascular mortality rates were higher in patients with increased HMGB1 (>= 2.4 ng/mL of median value) than those without increased HMGB1 (6.3% vs. 1.5%, P = 0.04; and 23% vs. 6.9%, P = 0.0003). Conclusion: Circulating concentration of HMGB1 on admission may be a potential and independent predictor of cardiovascular mortality in patients hospitalized for UA/NSTEMI within 24 h of onset. (C) 2012 Elsevier Ireland Ltd. All rights reserved.

OBJECTIVES The purpose of this study was to evaluate the effect of statin treatment on coronary plaque composition and morphology by optical coherence tomography (OCT), grayscale and integrated backscatter (IB) intravascular ultrasound (IVUS) imaging. BACKGROUND Although previous studies have demonstrated that statins substantially improve cardiac mortality, their precise effect on the lipid content and fibrous cap thickness of atherosclerotic coronary lesions is less clear. While IVUS lacks the spatial resolution to accurately assess fibrous cap thickness, OCT lacks the penetration of IVUS. We used a combination of OCT, grayscale and IB-IVUS to comprehensively assess the impact of pitavastatin on plaque characteristics. METHODS Prospective serial OCT, grayscale and IB-IVUS of nontarget lesions was performed in 42 stable angina patients undergoing elective coronary intervention. Of these, 26 received 4 mg pitavastatin after the baseline study; 16 subjects who refused statin treatment were followed with dietary modification alone. Follow-up imaging was performed after a median interval of 9 months. RESULTS Grayscale IVUS revealed that in the statin-treated patients, percent plaque volume index was significantly reduced over time (48.5 +/- 10.4%, 42.0 +/- 11.1%; p = 0.033), whereas no change was observed in the diet-only patients (48.7 +/- 10.4%, 50.4 +/- 11.8%; p = NS). IB-IVUS identified significant reductions in the percentage lipid volume index over time (34.9 +/- 12.2%, 28.2 +/- 7.5%; p = 0.020); no change was observed in the diet-treated group (31.0 +/- 10.7%, 33.8 +/- 12.4%; p = NS). While OCT demonstrated a significant increase in fibrous cap thickness (140 +/- 42 mu m, 189 +/- 46 mu m; p = 0.001), such changes were not observed in the diet-only group (140 +/- 35 mu m, 142 +/- 36 mu m; p = NS). Differences in the changes in the percentage lipid volume index (-6.8 +/- 8.0% vs. 2.8 +/- 9.9%, p = 0.031) and fibrous cap thickness (52 +/- 32 mu m vs. 2 +/- 22 mu m, p < 0.001) over time between the pitavastatin and diet groups were highly significant. CONCLUSIONS Statin treatment induces favorable plaque morphologic changes with an increase in fibrous cap thickness, and decreases in both percentage plaque and lipid volume indexes. (J Am Coll Cardiol Img 2012;5:169-77) (C) 2012 by the American College of Cardiology Foundation

Aims Pathological and clinical optical coherence tomography (OCT) studies have indicated that acute coronary syndrome (ACS) lesions have either ruptured fibrous caps (RFC-ACS) or intact fibrous caps (IFC-ACS). Although computed tomographic (CT) angiographic characteristics of RFC-ACS include low-attenuation plaques and positive plaque remodelling, features associated with IFC-ACS have not been previously described. The aim of this study was to assess the CT characteristics of IFC-ACS lesions. Methods and results Seventy-four patients with ACS/stable angina consented to multimodality imaging, of which 66 underwent CT angiography. Of these, 57 culprit lesions in 57 patients were evaluated with sufficient image quality from all four of OCT, angioscopy, intravascular ultrasound, and CT angiography. Intraluminal thrombus was assessed by OCT/angioscopy, and culprit lesions further classified by OCT-based demonstration of fibrous cap integrity. Of 35 culprit lesions with ACS, OCT revealed IFC with thrombus in 10 (29%) and RFC in the remaining 25 (71%); all 22 lesions with stable angina had intact fibrous caps. Fibrous caps were significantly thinner in RFC-ACS than IFC-ACS and stable angina (45 +/- 12, 131 +/- 57, and 321 +/- 146 mu m, respectively; P = 0.001). CT angiography revealed that low-attenuation plaques were more frequently observed in RFC-ACS than IFC-ACS and stable angina (88, 40, and 18%; P = 0.001) lesions. Similarly, positive remodelling was more predominantly seen in RFC-ACS than IFC-ACS and stable angina (96, 20, and 14%; P = 0.001). However, none of the specific CT angiography features clearly distinguished IFC-ACS from stable lesions. Conclusion In contrast to the situation with RFC-ACS, distinct culprit lesion characteristics associated with non-rupture-related mechanisms are not identified by CT angiography. It will therefore not be possible to differentiate plaques likely to develop IFC-ACS from stable plaques.

Coronary computed tomography angiography (CTA) can assess plaque characteristics and plaque size noninvasively. The purpose of this study was to investigate whether coronary CTA before percutaneous coronary intervention (PCI) can predict the no-reflow phenomenon during PCI. Seventy-eight patients [acute coronary syndrome (ACS) = 43, stable angina pectoris (SAP) = 35, male/female = 72/6, age: 65 +/- A 10 years] who underwent 16- or 64-slice CTA in the 4 weeks before PCI were enrolled. The low attenuation plaque size on CTA was compared between patients with (NR+) and without the no-reflow phenomenon (NR-). No-reflow phenomenon was observed in 11 patients, including 10 patients with ACS and 1 patient with SAP. Low attenuation plaque was detected in 9 (82%) NR(+) lesions and 35 (52%) NR(-) lesions. The length of low attenuation plaque was significantly longer in NR(+) than in NR(-) patients (9.0 +/- A 6.5 vs. 1.6 +/- A 2.7 mm, p < 0.0001). On step-wise regression analysis, ACS (p = 0.036, 95% CI = 0.009-0.258) and the presence of low attenuation plaque with a length > 4.7 mm (p < 0.001, 95% CI = 0.447-0.778) were significant independent predictors of NR(-) no-reflow phenomenon. Low attenuation plaque with lesion length of > 4.7 mm on coronary CTA and ACS were the significant predictors for the no-reflow phenomenon during PCI. Coronary CTA assessment before PCI would be useful to predict coronary events during PCI in advance.