[신간의 별자리x] 우리/미술, 그리고 ‘슬픔의 박물관’

Summary Background Since December, 2019, Wuhan, China, has experienced an outbreak of coronavirus disease 2019 (COVID-19), caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Epidemiological and clinical characteristics of patients with COVID-19 have been reported but risk factors for mortality and a detailed clinical course of illness, including viral shedding, have not been well described. Methods In this retrospective, multicentre cohort study, we included all adult inpatients (≥18 years old) with laboratory-confirmed COVID-19 from Jinyintan Hospital and Wuhan Pulmonary Hospital (Wuhan, China) who had been discharged or had died by Jan 31, 2020. Demographic, clinical, treatment, and laboratory data, including serial samples for viral RNA detection, were extracted from electronic medical records and compared between survivors and non-survivors. We used univariable and multivariable logistic regression methods to explore the risk factors associated with in-hospital death. Findings 191 patients (135 from Jinyintan Hospital and 56 from Wuhan Pulmonary Hospital) were included in this study, of whom 137 were discharged and 54 died in hospital. 91 (48%) patients had a comorbidity, with hypertension being the most common (58 [30%] patients), followed by diabetes (36 [19%] patients) and coronary heart disease (15 [8%] patients). Multivariable regression showed increasing odds of in-hospital death associated with older age (odds ratio 1·10, 95% CI 1·03–1·17, per year increase; p=0·0043), higher Sequential Organ Failure Assessment (SOFA) score (5·65, 2·61–12·23; p Interpretation The potential risk factors of older age, high SOFA score, and d-dimer greater than 1 μg/mL could help clinicians to identify patients with poor prognosis at an early stage. Prolonged viral shedding provides the rationale for a strategy of isolation of infected patients and optimal antiviral interventions in the future. Funding Chinese Academy of Medical Sciences Innovation Fund for Medical Sciences; National Science Grant for Distinguished Young Scholars; National Key Research and Development Program of China; The Beijing Science and Technology Project; and Major Projects of National Science and Technology on New Drug Creation and Development.

Clinical course and risk factors for mortality of adult inpatients with COVID-19 in Wuhan, China: a retrospective cohort study

BACKGROUND: The need for repeated treatment of restenosis of a treated vessel remains the main limitation of percutaneous coronary revascularization. Because sirolimus (rapamycin) inhibits the proliferation of lymphocytes and smooth-muscle cells, we compared a sirolimus-eluting stent with a standard uncoated stent in patients with angina pectoris. METHODS: We performed a randomized, double-blind trial to compare the two types of stents for revascularization of single, primary lesions in native coronary arteries. The trial included 238 patients at 19 medical centers. The primary end point was in-stent late luminal loss (the difference between the minimal luminal diameter immediately after the procedure and the diameter at six months). Secondary end points included the percentage of in-stent stenosis of the luminal diameter and the rate of restenosis (luminal narrowing of 50 percent or more). We also analyzed a composite clinical end point consisting of death, myocardial infarction, and percutaneous or surgical revascularization at 1, 6, and 12 months. RESULTS: At six months, the degree of neointimal proliferation, manifested as the mean (+/-SD) late luminal loss, was significantly lower in the sirolimus-stent group (-0.01+/-0.33 mm) than in the standard-stent group (0.80+/-0.53 mm, P<0.001). None of the patients in the sirolimus-stent group, as compared with 26.6 percent of those in the standard-stent group, had restenosis of 50 percent or more of the luminal diameter (P<0.001). There were no episodes of stent thrombosis. During a follow-up period of up to one year, the overall rate of major cardiac events was 5.8 percent in the sirolimus-stent group and 28.8 percent in the standard-stent group (P<0.001). The difference was due entirely to a higher rate of revascularization of the target vessel in the standard-stent group. CONCLUSIONS: As compared with a standard coronary stent, a sirolimus-eluting stent shows considerable promise for the prevention of neointimal proliferation, restenosis, and associated clinical events.

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A Randomized Comparison of a Sirolimus-Eluting Stent with a Standard Stent for Coronary Revascularization

Alice K. Jacobs, MD, FACC, FAHA, Chair 

Jeffrey L. Anderson, MD, FACC, FAHA, Chair-Elect 

Nancy Albert, PhD, CCNS, CCRN, FAHA

Mark A. Creager, MD, FACC, FAHA

Steven M. Ettinger, MD, FACC

Robert A. Guyton, MD, FACC

Jonathan L. Halperin, MD, FACC, FAHA

Judith S. Hochman, MD, FACC, FAHA

2011 ACCF/AHA/SCAI Guideline for Percutaneous Coronary Intervention: A Report of the American College of Cardiology Foundation/American Heart Association Task Force on Practice Guidelines and the Society for Cardiovascular Angiography and Interventions

http://www.columbiamedicine.org/education/r/Cardiology/ACS/Plavix/PCI-CURE.pdf

Effects of pretreatment with clopidogrel and aspirin followed by long-term therapy in patients undergoing percutaneous coronary intervention: the PCI-CURE study.

This paper presents a novel method for measuring local blood velocity and quantifying volume flow directly from cross-sectional intravascular ultrasound (IVUS) using a conventional IVUS catheter. This method is based on multiple decorrelation analysis of radio frequency echo signals. The velocity measurement is obtained by comparing the measured decorrelation value with a priori knowledge of the beam characteristics of the ultrasound transducer used. Volume flow is derived by integrating the velocity vector with its corresponding area element over the vessel cross-section. The proposed method was validated in vivo in pig experiments by comparing IVUS-flow data to the reference flow obtained with an electromagnetic (EM) flowmeter. An excellent correlation was observed between IVUS- and EM-flow data. No significant differences in the mean volume flow were found between the two methods. Results of this study demonstrate the potential of assessing vessel geometry simultaneously with functional parameters using the decorrelation analysis method.

Quantification of blood volume flow by decorrelation analysis of radio-frequency intravascular echo signals

Cardiovascular disease has long been the leading cause of death in developed countries and it is rapidly gaining similar status in developing countries. Sudden heart attacks remain the primary cause of death in the United States. In the year 2004 it is estimated that more than 1.4 million Americans, and more than 19 million others worldwide, experienced a life-threatening heart attack; these unpredicted attacks account for the majority of the $280 billion burden of cardiovascular diseases. Coronary artery disease (CAD) currently claims over 12.9 million American patients. In addition, CAD is the leading cause of premature, permanent disability in the U.S. labor force and accounts for about 1/5 of all disability allowances by the Social Security Administration. 1 Dept. of Computer Science, University of Houston, TX 2 Dept. of Cardiology, University of Athens, Greece 3 Cardiovascular Research Foundation, New York, NY 4 Dept. of Mechanical Engineering, University of Houston, TX 5 Baylor College of Medicine, Houston, TX 6 Dept. of Cardiology, University of Aarhus, Denmark 7 Association for Eradication of Heart Attack, Houston, TX Signal-Processing Approaches to Risk Assessment in Coronary Artery Disease Ioannis A. Kakadiaris, Sean M. O’Malley, Manolis Vavuranakis, Stéphane Carlier, Ralph Metcalfe, Craig J. Hartley, Erling Falk, and Morteza Naghavi Cardiovascular disease has long been the leading cause of death in developed countries and it is rapidly gaining similar status in developing countries. Sudden heart attacks remain the primary cause of death in the United States. In the year 2004 it is estimated that more than 1.4 million Americans, and more than 19 million others worldwide, experienced a life-threatening heart attack; these unpredicted attacks account for the majority of the $280 billion burden of cardiovascular diseases. Coronary artery disease (CAD) currently claims over 12.9 million American patients. In addition, CAD is the leading cause of premature, permanent disability in the U.S. labor force and accounts for about 1/5 of all disability allowances by the Social Security Administration. CARDIOLOGY’S RECENT PARADIGM SHIFT Coronary artery disease occurs as a result of atherosclerosis, a condition in which fatty plaques build up on the walls of the coronary arteries. If these plaques rupture, thrombosis may occur and obstruct the flow of blood to the heart, thus causing a potentially fatal heart attack. Some plaques present a particularly high risk of rupture; these are defined as vulnerable plaques. In the past decade, the field of cardiology has witnessed a major paradigm shift. Previously, gradually-accumulating fatty deposits and the consequent narrowing of the coronary arteries were thought to be the culprits in acute cardiac events. Today, cardiovascular specialists know that heart attacks are caused by inflammation of the coronary arteries and thrombosis-related complications of vulnerable plaques. As a result, the discovery of vulnerable plaque has the definition of a vulnerable patient, i.e., an individual with a high likelihood of experiencing a heart attack in the near future [1]. CARDIOVASCULAR RISK SCREENING Atherogenesis, or the formation of plaque, starts at a very early age and takes place over many years. The classification of plaque formation is based on a timeline from the initial inflammation to the lipid-rich plaque that leads to myocardial infarction. There are 140 million Americans over the age of 35 who are at risk of a heart attack; among this population, those in the range of 45-75 years are at highest risk for loss of productive life years. About 50-60 million people in this category may not exhibit clinical evidence of the disease, and may or may not have risk factors (race, sex, family history, hyperlipidemia, hypertension, diabetes, etc.), but they are still at risk of a heart attack. Since approximately 50% of deaths relating to acute cardiac events occur in such individuals with no prior symptoms, there is an urgent need for a wide-area screening program. Toward this end, the Association for Eradication of Heart Attack (a non-profit organization based in Houston, Texas) has developed the Screening for Heart Attack Prevention and Education (SHAPE) program, which promotes screening based on a battery of increasingly invasive tests. Emerging diagnostic tests—unavailable even a few years ago—to assess patient vulnerability factors include novel genetic and serum biomarkers such as the inflammatory marker C-reactive protein (CRP); noninvasive imaging tests such as computed tomography (CT), ultrasonography (for which relevant risk-scoring methods have been developed), and magnetic resonance (MR) imaging; and interventional catheter-based tools that allow precise, localized assessment. All of these provide unprecedented opportunities for early detection and risk stratification for potentially vulnerable patients. But what effect in our picture of vulnerable population would broad application of these tools have? It is estimated that screening with these techniques would identify 2-3 million additional individuals with lesions in their coronary arteries that are significant enough to require intervention. However, such a screening program would generate a huge influx of raw imaging data. For a single patient, a number of multidimensional imaging datasets are collected during the screening process, with increasing levels of storage and analysis complexity (2-D, 3-D, 2-D+time, 3-D+time, etc.). Applying these techniques to all those requiring diagnostic imaging, it is apparent that the amount of data that will be produced is overwhelming. Consequently, computational tools to assist in analyses of the pathological conditions that underlie sudden cardiac events are in high demand. INTRAVASCULAR ULTRASOUND-BASED IDENTIFICATION OF VULNERABLE PLAQUE Detection of the vulnerable plaques, particularly the rupture-prone vulnerable plaques (which are the culprit of many heart attacks and strokes) is one of the most active areas of research in both the cardiology and biomedical imaging communities. While there exist some non-invasive technologies (mentioned earlier) that can assess plaques morphologically, to the best of our knowledge no technology currently exists to reliably characterize plaques as vulnerable or non-vulnerable in a living human. To assist with this task, invasive technologies that are currently available, or under development, include visible-light angioscopy, near-infrared optical coherence tomography, thermography, spectroscopy, and intravascular ultrasound (IVUS). Among these technologies, IVUS is a particularly attractive option as it is wellknown, widely-available, has a long history of use, and is clinically-approved. Since the mid-1990’s, interest in IVUS signal processing has increased dramatically due to the emergence of frequency-domain techniques, which have enabled in vivo characterization of vessel and plaque tissue properties [2]. Yet in spite of its power, the major drawback of IVUS has been its inability to provide information about plaque vulnerability, i.e., an assessment of whether a plaque is stable and requires little or no treatment, or vulnerable and requires more aggressive intervention. To address this limitation, the presence of vasa vasorum (VV) microvessels (shown in Fig. 1a) could be exploited. While normally these vessels simply feed larger vessels, recent evidence suggests that VV proliferation is a strong marker of plaque inflammation, and a preceding or concomitant factor associated with plaque rupture and instability [3, 4]. As such, a technology capable of imaging VV in vivo would provide the clinician with a powerful indicator of plaque vulnerability. However, so far the VV could not be imaged in vivo; even utilizing a high-resolution intravascular technology such as IVUS, the small scale and echo-transparency of the VV typically renders them invisible. In what follows, we introduce a novel method that enables (for the first time) IVUS detection of atherosclerotic plaque inflammation based on quantification of VV density and perfusion. This method consists of a contrast-enhanced IVUS acquisition protocol and a series of signal/image-processing techniques to detect VV in the resulting contrast-enhanced sequences. DATA ACQUISITION To acquire the IVUS data, we have used both a rotating single-crystal 40 MHz scanner (Boston Scientific, Inc.; GalaxyTM) and a solid-state phased-array 20 MHz scanner (Volcano Therapeutics, Inc.; InvisionTM). For contrast we utilize OptisonTM: an ultrasound contrast agent composed of albumin microspheres filled with octafluoropropane gas. The IVUS catheter is advanced percutaneously, transluminally into the patient; and imaging is typically performed near a suspect region of the arterial wall. First, a baseline IVUS signal is recorded for 1-2 min (“pre-injection” period). Next, the contrast agent is injected, temporarily washing out the IVUS signal due to the echo-opacity of the lumen (“during-injection” period). Finally, IVUS signals are collected for 1-2 min (“post-injection” period), followed by the injection of normal saline to flush residual microbubbles. During these periods the IVUS catheter is not moved. SIGNAL PROCESSING Following acquisition, our VV detection and imaging method consists of three steps. First, the IVUS sequence is gated to eliminate gross motion artifacts. Next, the region-of-interest of the vessel is tracked with a hybrid rigid/elastic registration technique such that relative catheter/vessel motions can be eliminated and elastic wall deformations compensated for. Finally, enhancement detection is performed using difference-imaging and statistical techniques. The resulting enhancement is visualized and quantified. Step 1: Frame Gating – In stationary-catheter IVUS studies, maintaining a fixed catheter position with regard to an anatomic point of reference is impossible in practice due

Signal-Processing Approaches to Risk Assessment in Coronary Artery Disease

Ventricular hydraulic power is defined as the instantaneous product of flow and pressure at the aortic root. This paper describes a system for non-invasive determination of LV power output based on simultaneous acquisition of applanation tonometry for aortic blood pressure (BP) evaluation and echo-Doppler signals for flow measurement. Acquisition is performed with a dedicated A/D system allowing on-line visualisation of Doppler power spectra and calibrated tonometric signals (using mean and diastolic cuff BP at the brachial level). Aortic BP is estimated either using an aorto-radial transfer function, either untransformed carotid BP. This method has been investigated in 10 normal volunteers. Visualisation of calibrated data during acquisition allowed recordings with a low variability (mean standard deviation of reconstructed systolic BP<5 mmHg). The expected increase in systolic BP was observed from carotid to radial sites. The mean peak power was 6/spl plusmn/2 W.

Non-invasive evaluation of left ventricular power output by simultaneous recordings of applanation tonometry and echocardiographic Doppler signals

IVUS based dosimetry and treatment planning.

BACKGROUND The intravascular ultrasound (IVUS) findings during repeat intervention for drug-eluting stent (DES) restenosis have not been well described. METHODS We identified 62 consecutive DES restenosis lesions (45 sirolimus-eluting stents and 17 paclitaxel-eluting stents) undergoing repeat intervention with pre and postintervention IVUS. Lumen, stent and intimal hyperplasia (stent minus lumen) areas were measured at the minimal lumen area (MLA) site and minimal stent area (MSA) site. RESULTS Repeat stent implantation was performed in 55 lesions (88.7%). Overall, MLA increased from 2.3 +/- 0.7 mm(2) preintervention to 4.6 +/- 1.6 mm(2) postintervention. Preintervention MLA was seen at exactly the preintervention MSA site in 42%, while 73% of postintervention MLAs were located at the preintervention MSA site. There was a strong correlation between the preintervention MSA and the postintervention MLA (r = 0.79; p < 0.001). Preintervention MSA was the strongest independent predictor of a larger postintervention MLA (coefficient 0.72; p < 0.001). CONCLUSIONS The preintervention MSA was a major predictor of larger lumen area after repeat intervention for DES restenosis. Several IVUS studies have shown that stent dimensions do not change over time. Therefore, the MSA of the original stent implantation procedure still has the greatest impact on subsequent interventions to treat DES restenosis.

Stephane Carlier

Papers

Quantification of blood volume flow by decorrelation analysis of radio-frequency intravascular echo signals

Signal-Processing Approaches to Risk Assessment in Coronary Artery Disease

Non-invasive evaluation of left ventricular power output by simultaneous recordings of applanation tonometry and echocardiographic Doppler signals

IVUS based dosimetry and treatment planning.

Treatment of restenotic drug-eluting stents: an intravascular ultrasound analysis.