Thura T. Abd

Incidence and clinical characteristics of takotsubo cardiomyopathy post-aneurysmal subarachnoid hemorrhage

a Division of Cardiology, Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, MD, United States b Division of Cardiology, Department of Medicine, Emory University School of Medicine, Atlanta, GA, United States c Division of Internal Medicine, Department of Medicine, Emory University School of Medicine, Atlanta, GA, United States d Department of Neurosurgery, Emory University School of Medicine, Atlanta, GA, United States e Department Neurology, Emory University School of Medicine, Atlanta, GA, United States

Genetics and Personalized Medicine—a Role in Statin Therapy?

Pharmacogenetics uses the genetic variation in metabolic pathways to identify groups of patients who may respond differently in terms of therapeutic and adverse effects. Much clinical interest lies in drug metabolism and the opportunity to improve prescribing efficacy and safety. Owing to widespread use and increasing concern regarding side effects, statins are of significant interest in this area. Among other benefits, statins have been shown to improve lipid profiles and reduce coronary heart disease event rates in many populations. However, variability in drug response exists, and genetic variability may be a contributing factor. Our primary goal is to feature the most important genes involved in lipid metabolism, clinical outcomes, and statin-induced side effects, highlighting genome-wide association studies and the candidate gene approach.

A coupled chemo-fluidic computational model for thrombogenesis in infarcted left ventricles

A coupled chemo-fluidic computational model for investigating flow-mediated thrombogenesis in infarcted left ventricles (LVs) is proposed. LV thrombus (LVT) formation after the acute myocardial infarction (AMI) may lead to thromboembolic events that are associated with high mortality and morbidity, and reliable stratification of LVT risk is the key to managing the treatment of AMI patients. There have been several studies emphasizing the importance of LV blood flow patterns on thrombus formation; however, given the complex interplay between ventricular flow dynamics and biochemistry of thrombogenesis, current understanding is mostly empirical. In the present model, blood flow in the LV is obtained by solving the incompressible Navier-Stokes equations, and this is coupled to the biochemical modeling of the coagulation cascade, platelet activation, and fibrinogen polymerization. The coupled model is used to examine the effect of ventricular flow patterns on thrombogenesis in modeled ventricles. It is expected that the method developed here will enable in-depth studies of thrombogenesis in patient-derived infarcted LV models.

Estimating coronary blood flow using CT transluminal attenuation flow encoding: Formulation, preclinical validation, and clinical feasibility

BACKGROUND We present the formulation and testing of a new CT angiography (CTA)-based method for noninvasive measurement of absolute coronary blood flow (CBF) termed transluminal attenuation flow encoding (TAFE). CTA provides assessment of coronary plaque but does not allow for detection of vessel specific ischemia. A simple and direct method to calculate absolute CBF from a standard CTA could isolate the functional consequence of disease and aid therapy decisions. METHODS We present the theoretical framework and initial testing of TAFE. Nine canine models of ischemic heart disease were prepared and underwent CT imaging and microsphere measurements of myocardial blood flow. Additionally, 39 acute chest pain patients with normal coronary arteries underwent coronary CTA. We applied TAFE to calculate absolute CBF in the coronary arteries using 4 vessel input parameters including transluminal attenuation gradient, cross-sectional area, length, and the contrast bolus duration derived from the arterial input function. RESULTS In animal studies, TAFE-derived CBF in the left anterior descending, left circumflex, and right coronary artery was 20.8 ± 10.4 mL/min, 27.0 ± 13.4 mL/min, and 6.0 ± 3.7 mL/min, respectively. TAFE-derived CBF divided by myocardial mass strongly correlated with microsphere myocardial blood flow (R(2) = 0.90, P < .001). In human studies, TAFE-derived CBF in the left anterior descending, left circumflex, and right coronary artery was 26.4 ± 10.7 mL/min, 20.1 ± 13.0 mL/min, and 43.2 ± 40.9 mL/min, respectively. CBF per unit mass was 0.93 ± 0.48 mL/g/min in patients. Interobserver variability was minimal with excellent correlation (R = 0.96, P < .0001) and agreement (mean difference, 4.2 mL/min). CONCLUSION TAFE allows for quantification of absolute CBF from a standard CTA acquisition and may provide functional significance of coronary disease without complex computational methods.

Rare Elizabethkingia meningosepticum meningitis case in an immunocompetent adult

Though Elizabethkingia meningosepticum typically causes meningitis in neonates, its occurrence in adult is rare, with sixteen cases described worldwide. We report a case of E. meningosepticum meningitis in an immunocompetent adult. Bacterial identification was made a day earlier than conventional method by using matrix assisted laser desorption ionization time-of-flight (MALDI-TOF) Vitek mass spectrometry RUO (VMS), which resulted in successful treatment with rifampin, trimethoprim-sulfamethoxazole, levofloxacin and minocycline.

Cardiovascular Disease Risk Prediction - Integration into Clinical Practice

Keywords Riskprediction .Atherosclerosis .CoronaryarterydiseaseIntroductionAnestimated83.6millionAmericanadultshaveatherosclerot-ic cardiovascular vascular disease (CVD) and one in everythreedeathsintheUnitesStatesisattributedtoCVD.Coronaryheartdisease(CHD)alonecausedaboutoneofeverysixdeathsin the US in 2008. More than half of patients who present assudden cardiac death have no antecedent symptoms [1].Risk assessment and stratification of asymptomatic adultsare essential parts of CVD preventive strategies [2]. Interven-tions usually have the same relative-risk reduction acrossdifferent risk strata. The highest absolute-risk reduction willoccur for individuals with the highest pre-treatment risk. Ac-cordingly, determination of absolute risk is crucial to ade-quately assess the risk-benefit ratio.The absolute risk of a cardiovascular event can be estimat-ed from the presence or absence of certain risk factors (RFs).Those RFs usually coexist and interact with each other. Mildelevation in multiple RFs has much more effect on absoluteriskthanasubstantialelevationofasingleRF.Inotherwords,an integrated risk calculation is a much better predictor offuture vascular events than any single RF [3–5]. Without aformal way to assess CVD risk, both patients and physicianstend to overestimate or underestimate the actual risk [6–8].These facts highlight the importance of having formalmethods for CVD risk prediction usually using some kind ofrisk assessment score or calculator. Every major guideline forthe prevention of CVD stresses risk assessment as the initialapproach in evaluating a patient [9–12].In this article, we briefly summarize the most commonlyused CVD risk assessment methods. We highlight eachmethod’s strengths and weaknesses and provide an updatedreview on the current role of lifetime risk calculations. Be-causeofincreasingliteratureofcoronaryarterycalcium(CAC) as a measure of atherosclerosis, we review recentstudies of its role in risk evaluation. Finally, we evaluate thebest ways to incorporate current risk assessment scores intoclinical practice.Current CVD Risk ScoresThere are many CVD risk prediction models available toclinicians. Table 1 summarizes key features of the most com-monly used CVD risk scores. The Framingham Risk Score(FRS) is a landmark achievement [13]. The version used in2001 Adult Treatment Panel III (ATP III) estimates 10-yearrisk of development of “hard” CHD. In 2008, the FRS forglobal CVD was developed to predict all major CVD out-comes (Table 1)[14]. Thirty-years [15] and lifetime [16]riskmodels have also been developed from the Framingham co-hort.Reynoldsriskscoreuseshigh-sensitivityC-reactivepro-tein (hs-CRP) and parental history of myocardial infarctionprior to age 60 years with the traditional Framingham RFs.Similarly, multiple risk scores have been derived from Euro-peancohortsincludingtheASSIGN[17],SCORE[5],QRISK[18] and PROCAM [19] scores (Table 1).Limitations of Currently Available Risk ScoresRiskscoreshaveseveralwellacknowledgedlimitations.First,becausemostsubjectswithhighriskburden(≥1RFs)willnotdevelop CVD over the following 10-year period, risk scores

Effect of intravenous infusion of iodinated contrast media on the coronary blood flow in dogs

Background Coronary computed tomography angiography (CCTA) is obtained using peripheral intravenous iodinated contrast agents (ICA) injection. There is continuing attempts to derive coronary physiological information like coronary blood flow (CBF) and/or fractional flow reserve from CCTA images. However, no data is available regarding the effect of peripheral intravenous injection of ICA on CBF. Methods A series of 4 experiments was performed using healthy mongrel dogs. All dogs underwent anesthesia and open thoracotomy with placement of ultrasound flowmeter to one of the coronary artery to provide real time absolute CBF measurements. Different infusion protocols of Isovue-370 and Visipaque-320 were injected into a peripheral vein. Similar doses of normal saline injection were performed to be used as controls. The effect of iodinated contrast media injection on absolute coronary blood flow was monitored and recorded. Results Injection of normal saline in the peripheral vein did not produce any significant increase in CBF. Peripheral intravenous injection of ICA resulted in a consistent increase of 40–73% in absolute CBF as recorded 5 minutes post-contrast administration. The contrast effect starts about 30 seconds and peaks at about 2 minutepost-contrast injection then slowly fades away in the following 10–15 min. The increase in the CBF was dose related. There was greater increase in the CBF to 50 ml infusion compared to 25 ml infusion of both Visipaque and Isovue. Conclusions Peripheral venous administration of iodinated contrast-media in dogs results in a dose related, significant and prolonged increase in CBF.