Early bare-metal stent thrombosis presenting with cardiogenic shock: a case report

<p>Abstract</p> <p>Introduction</p> <p>Although stents have improved the safety and efficacy of percutaneous coronary interventions, coronary stent thrombosis remains a serious complication.</p> <p>Case presentation</p> <p>We present the case of a 64-year-old Caucasian man from Greece, with symptoms and electrocardiographic findings suggestive of acute inferior myocardial infarction, who complained of chest pain and rapidly developed cardiogenic shock 48 hours after primary percutaneous coronary intervention.</p> <p>Conclusion</p> <p>The most common cause of early bare-metal stent thrombosis is stent malapposition. Intravascular ultrasound is the preferred method to recognize predictors of coronary events that are not detected by angiography.</p

Intravascular ultrasound imaging of human coronary arteries in vivo. Analysis of tissue characterizations with comparison to in vitro histological specimens.

BackgroundIntravascular ultrasound imaging was performed in 27 patients after coronary balloon angioplasty to quantify the lumen and atheroma cross-sectional areas.Methods and resultsA 20-MHz ultrasound catheter was inserted through a 1.6-mm plastic introducer sheath across the dilated area to obtain real-time images at 30 times/sec. The ultrasound images distinguished the lumen from atheroma, calcification, and the muscular media. The presence of dissection between the media and the atheroma was well visualized. These observations of tissue characterization were compared with an in vitro study of 20 human atherosclerotic artery segments that correlated the ultrasound images to histological preparations. The results indicate that high-quality intravascular ultrasound images under controlled in vitro conditions can provide accurate microanatomic information about the histological characteristics of atherosclerotic plaques. Similar quality cross-sectional ultrasound images were also obtained in human coronary arteries in vivo. Quantitative analysis of the ultrasound images from the clinical studies revealed that the mean cross-sectional lumen area after balloon angioplasty was 5.0 +/- 2.0 mm2. The mean residual atheroma area at the level of the prior dilatation was 8.7 +/- 3.4 mm2, which corresponded to 63% of the available arterial cross-sectional area. At the segments of the coronary artery that appeared angiographically normal, the ultrasound images demonstrated the presence of atheroma involving 4.7 +/- 3.2 mm2, which was a mean of 35 +/- 23% of the available area bounded by the media.ConclusionsIntravascular ultrasound appears to be more sensitive than angiography for demonstrating the presence and extent of atherosclerosis and arterial calcification. Intracoronary imaging after balloon angioplasty reveals that a significant amount of atheroma is still present, which may partly explain why the incidence of restenosis is high after percutaneous transluminal coronary angioplasty

Measuring subluxation of the hemiplegic shoulder: Reliability of a method

Objective: Subluxation of the shoulder after stroke can be measured according to the method described by Van Langenberghe and Hogan. Methods: To evaluate the reliability of this method, the shoulder radiographs of 25 patients were available for this study. Two independent raters each assessed these radiographs twice. Results: The intrarater reliability was good: percentage of agreement was 88 and 84%, weighted κ, 0.69 [95% confidence interval (CI), 0.38-1 0] and 0.78 (95% CI, 0.60-0.95) for raters 1 and 2, respectively. The interrater reliability was poor: percentage of agree ment was 36 and 28%, κ, 0.11 (95% CI, 0.0-0.31) and 0.09 (95% CI, 0.0-0.23) in sessions 1 and 2, respectively. Subsequently the original method was adjusted by com bining two categories (no subluxation and beginning subluxation) into one (“no clin ically important subluxation”). Conclusions: After this adjustment of the categories, the interrater reliability improved [percentage of agreement, 72%, and κ, 0.49 (95% CI, 0.18-0.80)], but did not reach acceptable values

Thermally Responsive Amphiphilic Conetworks and Gels Based on Poly(N‑isopropylacrylamide) and Polyisobutylene

Novel amphiphilic conetworks (APCN) consisting of thermoresponsive poly(N-isoproplyacrylamide) (PNiPAAm) cross-linked by hydrophobic methacrylate-telechelic polyisobutylene (MA-PIB-MA) were successfully synthesized in a broad composition range. The resulting PNiPAAm-l-PIB conetworks (“l” stands for “linked by”) were obtained by radical copolymerization of NiPAAm with MA-PIB-MA in tetrahydrofuran, a cosolvent for all the components. Low amounts of extractables substantiated efficient network formation. The composition dependent two glass transition temperatures (Tg) by DSC analysis indicate microphase separation of the cross-linked components without mixed phases. It was found that the PNiPAAm-l-PIB conetworks are uniformly swellable in both water and n-hexane; i.e., these new materials behave either as hydrogels or as hydrophobic gels in aqueous or nonpolar media, respectively. The uniform swelling in both polar and nonpolar solutes indicates cocontinuous (bicontinuous) phase morphology. The equilibrium swelling degrees (R) depend on composition, that is, the higher the PIB content, the lower the R in water and the higher in n-hexane. The PNiPAAm phase keeps its thermoresponsive behavior in the conetworks as shown by significant decrease of the swelling degree in water between 20 and 35 °C. The lower critical solubility temperature (LCST) values determined by DSC are found to decrease from 34.1 °C (for the pure PNiPAAm homopolymer) to the range of 25–28 °C in the conetworks, and the extent of the LCST decrease is proportional with the PIB content. Deswelling-swelling, i.e., heating–cooling, cycle indicates insignificant hysteresis in these new thermoresponsive materials. This indicates that PNiPAAm-l-PIB conetworks with predetermined and thermoresponsive swelling behavior can be designed and utilized in several advanced applications on the basis of results obtained in the course of this study

Functional assessment of coronary artery flow using adenosine stress dual-energy CT: a preliminary study

We attempted to assess coronary artery flow using adenosine-stress and dual-energy mode with dual-source CT (DE-CT). Data of 18 patients with suspected coronary arteries disease who had undergone cardiac DE-CT were retrospectively analyzed. The patients were divided into two groups: 10 patients who performed adenosine stress CT, and 8 patients who performed rest CT as controls. We reconstructed an iodine map and composite images at 120 kV (120 kV images) using raw data with scan parameters of 100 and 140 kV. We measured mean attenuation in the coronary artery proximal to the distal portion on both the iodine map and 120 kV images. Coronary enhancement ratio (CER) was calculated by dividing mean attenuation in the coronary artery by attenuation in the aortic root, and was used as an estimate of coronary enhancement. Coronary stenosis was identified as a reduction in diameter of >50% on CT angiogram, and myocardial ischemia was diagnosed by adenosine-stress myocardial perfusion scintigraphy. The iodine map showed that CER was significantly lower for ischemic territories (0.76 ± 0.06) or stenosed coronary arteries (0.77 ± 0.06) than for non-ischemic territories (0.95 ± 0.21, P = 0.02) or non-stenosed coronary arteries (1.07 ± 0.33, P < 0.001). The 120 kV images showed no difference in CER between these two groups. Use of CER on the iodine map separated ischemic territories from non-ischemic territories with a sensitivity of 86% and a specificity of 75%. Our quantification is the first non-invasive analytical technique for assessment of coronary artery flow using cardiac CT. CER on the iodine map is a candidate method for demonstration of alteration in coronary artery flow under adenosine stress, which is related to the physiological significance of coronary artery disease