Evaluation of a mandatory phishing training program for high-risk employees at a US healthcare system.

OBJECTIVE: The study sought to understand the impact of a phishing training program on phishing click rates for employees at a single, anonymous US healthcare institution. MATERIALS AND METHODS: We stratified our population into 2 groups: offenders and nonoffenders. Offenders were defined as those that had clicked on at least 5 simulated phishing emails and nonoffenders were those that had not. We calculated click rates for offenders and nonoffenders, before and after a mandatory training program for offenders was implemented. RESULTS: A total of 5416 unique employees received all 20 campaigns during the intervention period; 772 clicked on at least 5 emails and were labeled offenders. Only 975 (17.9%) of our set clicked on 0 phishing emails over the course of the 20 campaigns; 3565 (65.3%) clicked on at least 2 emails. There was a decrease in click rates for each group over the 20 campaigns. The mandatory training program, initiated after campaign 15, did not have a substantial impact on click rates, and the offenders remained more likely to click on a phishing simulation. DISCUSSION: Phishing is a common threat vector against hospital employees and an important cybersecurity risk to healthcare systems. Our work suggests that, under simulation, employee click rates decrease with repeated simulation, but a mandatory training program targeted at high-risk employees did not meaningfully decrease the click rates of this population. CONCLUSIONS: Employee phishing click rates decrease over time, but a mandatory training program for the highest-risk employees did not decrease click rates when compared with lower-risk employees.

Assessment of Employee Susceptibility to Phishing Attacks at US Health Care Institutions.

Importance: Cybersecurity is an increasingly important threat to health care delivery, and email phishing is a major attack vector against hospital employees. Objective: To describe the practice of phishing simulation and the extent to which health care employees are vulnerable to phishing simulations. Design, Setting, and Participants: Retrospective, multicenter quality improvement study of a convenience sample of 6 geographically dispersed US health care institutions that ran phishing simulations from August 1, 2011, through April 10, 2018. The specific institutions are anonymized herein for security and privacy concerns. Exposures: Simulated phishing emails received by employees at US health care institutions. Main Outcomes and Measures: Date of phishing campaign, campaign number, number of emails sent, number of emails clicked, and email content. Emails were classified into 3 categories (office related, personal, or information technology related). Results: The final study sample included 6 anonymized US health care institutions, 95 simulated phishing campaigns, and 2 971 945 emails, 422 062 of which were clicked (14.2%). The median institutional click rates for campaigns ranged from 7.4% (interquartile range [IQR], 5.8%-9.6%) to 30.7% (IQR, 25.2%-34.4%), with an overall median click rate of 16.7% (IQR, 8.3%-24.2%) across all campaigns and institutions. In the regression model, repeated phishing campaigns were associated with decreased odds of clicking on a subsequent phishing email (adjusted OR, 0.511; 95% CI, 0.382-0.685 for 6-10 campaigns; adjusted OR, 0.335; 95% CI, 0.282-0.398 for >10 campaigns). Conclusions and Relevance: Among a sample of US health care institutions that sent phishing simulations, almost 1 in 7 simulated emails sent were clicked on by employees. Increasing campaigns were associated with decreased odds of clicking on a phishing email, suggesting a potential benefit of phishing simulation and awareness. With cyberattacks increasing against US health care systems, these click rates represent a major cybersecurity risk for hospitals.

Coronary artery diameter related to calcium scores and coronary risk factors as measured with multidetector computed tomography: a substudy of the ACCURACY trial.

Arterial remodeling, an early change of atherosclerosis, can cause dilated arterial diameter. We measured coronary artery diameter with use of noncontrast 64-slice multidetector computed tomography (MDCT), and studied its association with coronary artery calcium levels and traditional coronary risk factors. We included 140 patients from the ACCURACY trial whose noncontrast MDCT images showed measurable coronary arteries. Using 3 measurements of left main coronary artery (LMCA) and right coronary artery (RCA) diameters within 3 mm of the ostium, we associated the results with traditional coronary risk factors and calcium scores. The prevalence of LMCA and RCA calcium was 22% and 51%, respectively. Mean arterial diameters were 5.67±1.18 mm (LMCA) and 4.66±1.08 mm (RCA). Correlations for LMCA and RCA diameters in 50 randomly chosen patients were 0.91 and 0.93 (interobserver) and 0.98 and 0.93 (intraobserver). Adjusted odds ratios for the relationship of LMCA and RCA diameters to calcium in male versus female patients were 5.65 (95% confidence interval [CI], 2.78-11.5) and 4.35 (95% CI, 2.24-8.47), respectively. Adjusted ratios and 95% CIs for the association of larger RCA diameter with age, hypertension, and body mass index were 1.36 (1.00-1.86), 3.13 (1.26-7.78), and 1.60 (1.16-2.22), respectively. Arterial diameters were larger in women and patients with higher calcium levels, and body mass index and hypertension were predictors of larger RCA diameters. These findings suggest a link between arterial remodeling and the severity of atherosclerosis.

Coronary calcifications and plaque characteristics in patients with end-stage renal disease: a computed tomographic study.

BACKGROUND: We examined the association between coronary artery calcifications, atherosclerotic burden, and plaque morphology in end-stage renal disease (ESRD) and non-ESRD patients undergoing 64-slice multidetector coronary computed tomographic angiography. METHODS: The prevalence, extent, and severity of coronary atherosclerosis, calcium burden, and plaque morphology were determined in ESRD patients (n=48), and calcium score-matched (n=39) and unmatched non-ESRD controls (n=29) undergoing computed tomographic angiography using dedicated plaque imaging software. RESULTS: ESRD was associated with a higher prevalence of calcified plaques (55.9% vs. 38.3 and 26.9% in the non-ESRD groups, P=0.005) and higher plaque calcium content (43.7 vs. 34.5% and 33.9%; P=0.003). Nonetheless, the calcium score correlated well with plaque burden (r=0.403 in ESRD vs. r=0.433 in non-ESRD, P<0.001 for both), and the diagnostic association between the calcium score and atherosclerotic lesions was good irrespective of ESRD (area under the curve 0.771 vs. 0.804; P=0.574). CONCLUSION: ESRD is associated with diffuse atherosclerosis and calcific plaque morphology. Nonetheless, the association between the calcium score and atherosclerotic burden is not affected by the presence of ESRD.

Detection and quantification of myocardial perfusion defects by resting single-phase 64-slice cardiac computed tomography angiography compared with SPECT myocardial perfusion imaging.

OBJECTIVE: Hypoenhanced regions on cardiac computed tomography angiography (CCTA) correlate with myocardial hypoperfusion. We evaluated the ability of resting single-phase 64-slice CCTA to detect the presence of myocardial infarction (MI) compared with nuclear myocardial perfusion imaging (MPI). METHODS: One hundred and forty symptomatic patients (age 66±12 years, 64% men) with an irreversible perfusion defect (n=69) or a normal/reversible perfusion defect (n=71) on MPI were subjected to CCTA for further evaluation. MI on CCTA was detected visually on the basis of areas of hypoattenuation (dark) in the myocardium and the corresponding Hounsfield Units (HU) were measured. RESULTS: CCTA accurately detected MI in 62 patients with an irreversible perfusion defect on MPI, yielding a sensitivity of 90%, a specificity of 94%, a negative predictive value of 91%, and a positive predictive value of 94%. The mean HU of normal and infarcted left ventricular myocardium was 107±23 and 16±40, respectively (P<0.001). An HU cut-off of 28 detected the presence of myocardial scar with 86% sensitivity and 59% specificity. The infarct volume measured by CCTA correlated well with the summed rest score (r=0.567; P<0.001) and the summed stress score (r=0.489; P<0.001) on MPI. In a substudy of 50 patients, the GE perfusion tool yielded a sensitivity of 92%, a specificity of 73%, an negative predictive value of 91%, and a positive predictive value of 76% in detecting MI. CONCLUSION: Resting single-phase CCTA is highly accurate in detecting and quantifying MI. This study highlights a novel clinical utility of CCTA in addition to assessment of plaque burden and stenosis with no risk of additional radiation or contrast exposure to the patient.

Computerized left ventricular regional ejection fraction analysis for detection of ischemic coronary artery disease with multidetector CT angiography.

Regional ejection fraction (REF) provides important functional information of the left ventricular regional myocardium. We aimed to test the diagnostic accuracy of computerized REF analysis for detecting the ischemia and significant stenosis with multidetector CT angiography (MDCT). This is a retrospective study including 155 patients who underwent MDCT scans for evaluation of coronary artery disease. Among them, 83 patients also underwent SPECT imaging and invasive coronary angiography (ICA). Two groups of patients were defined: Control group with 0 coronary artery calcium and normal global and regional ventricular function, and comparison group. REF measurement was performed on all patients using computerized software. Control group REF measurements will be used as reference standard (mean-2SD REF/mean global ejection fraction) to define abnormal REF. The sensitivity, specificity, positive and negative predictive value of REF in detecting perfusion defects (fixed and reversible) was 73, 80, 75 and 79 % respectively, in a patient based analysis of comparison group. The diagnostic accuracy of REF in predicting significant stenosis (>50 %) on ICA compared with SPECT was 72 versus 61 % and 85 versus 79 % in patient and vessel based analysis of comparison group, respectively. ROC curve analysis showed REF to be a better predictor of perfusion defects on SPECT compared with significant stenosis (>50 %) alone or stenosis combined with REF (P < 0.05). The computerized assessment of REF analysis is comparable to SPECT in predicting ischemia and a better predictor of significant stenosis than SPECT. This study also provides reference standard to define abnormal values.

Anomalous "High Take-Off" of the right coronary artery evaluated by coronary CT angiography.

Congenital coronary anomalies are uncommon but can cause sudden cardiac death or myocardial ischemia. Conventional coronary angiography is an invasive and expensive modality, sometimes unable to delineate the exact origin and course of an anomalous artery. In this case report, we describe an "extremely rare" anomaly of the right coronary artery where a 64-slice multidetector computed tomography provided valuable information regarding its exact site of the aortocoronary take-off and its spatial relationship with the great vessels. Knowledge of CT appearances and an understanding of the clinical significance of these anomalies are essential for making the correct diagnosis and planning patient treatment.

Aged garlic extract and coenzyme Q10 have favorable effect on inflammatory markers and coronary atherosclerosis progression: A randomized clinical trial.

BACKGROUND: Aged garlic extract (AGE) and coenzyme Q10 (CoQ10) have been shown to affect multiple cardiovascular risk factors. The current study evaluates the effect of AGE combined with CoQ10 on inflammatory markers and progression of coronary atherosclerosis compared with placebo. METHODS AND RESULTS: In this placebo-controlled, double-blind, randomized trial, 65 intermediate risk firefighters (age 55 ± 6 years) were treated with a placebo capsule or a capsule containing AGE and CoQ10 (AGE+CoQ10, 1200 and 120 mg, respectively) daily for 1 year. All participants underwent coronary artery calcium (CAC) scanning and C-reactive protein (CRP) at baseline and at 12 months. At 1 year, mean CAC progression was significantly lower in AGE+CoQ10 (32 ± 6 vs. 58 ± 8, P = 0.01) than placebo. Similarly, CRP were significantly decreased in AGE+CoQ10 compared with placebo (-0.12 ± 0.24 vs. 0.91 ± 0.56 mg/L, P < 0.05). After adjustment for age, gender, conventional cardiac risk factors, and statin therapy, AGE+CoQ10 was associated with 3.99 fold (95% 1.3-12.2, P = 0.01) lack of CAC progression compared with the placebo. CONCLUSION: AGE+CoQ10 are associated with beneficial effects on inflammatory markers and reduced progression of coronary atherosclerosis.

Body surface area is a predictor of coronary artery calcium, whereas body mass index is not.

INTRODUCTION: We sought to establish whether elevated BMI and body surface area (BSA), two measures of obesity, are predictors of coronary artery calcium (CAC). METHODS: We retrospectively analyzed 3172 consecutive patients who underwent calcium scoring at our center. We applied a multiple logistic regression model to estimate the independent association between BMI of at least 25 kg/m(2) and incidence of CAC with adjustment for covariates. We carried out the same analysis to find out if there is an independent association between BSA of at least 1.71 m(2) (commonly used definition for abnormally elevated BSA) and incidence of CAC. We also performed a sex subanalysis based on BMI and BSA. RESULTS: There were 2105 patients in the cohort with BMI of at least 25 kg/m(2) compared with 1067 patients with BMI of less than 25 kg/m(2). After adjustment for covariates, a significant association was not found between increased BMI and incidence of CAC. In addition, no significant findings were found in the sex subanalysis. A total of 2760 patients had a BSA of at least 1.71 m(2) compared with 412 patients with BSA of less than 1.71 m(2). After adjustment for covariates, a significant association (odds ratio 2.08, 95% confidence interval 1.16-3.73, P=0.014) was found between elevated BSA and CAC incidence. There were 89 men with BSA of at least 1.9 m(2) and 2248 with BSA of at least 1.9 m(2). After adjustment for covariates, the logistic regression model showed a significant association (odds ratio 2.24, 95% confidence interval 1.19-4.21, P=0.012) between BSA of at least 1.9 m(2) and incidence of CAC. CONCLUSION: Elevated BSA is a predictor of CAC incidence, whereas elevated BMI is not. Moreover, elevated BSA is a predictor of CAC incidence particularly in men.

Myocardial hypo-enhancement on resting computed tomography angiography images accurately identifies myocardial hypoperfusion.

OBJECTIVE: The objective of this study was to test the diagnostic accuracy of myocardial CT perfusion (CTP) imaging using color and gray-scale image analysis. BACKGROUND: Current myocardial CTP techniques have varying diagnostic accuracy and are prone to artifacts that impair detection. This study evaluated the diagnostic accuracy of color and/or gray-scale CTP and the application of artifact criteria to detect hypoperfusion. METHODS: Fifty-nine prospectively enrolled patients with abnormal single-photon emission computed tomography (SPECT) studies were analyzed. True hypoperfusion was defined if SPECT hypoperfusion corresponded to obstructive coronary stenoses on CT angiography (CTA). CTP applied color and gray-scale myocardial perfusion maps to resting CTA images. Criteria for identifying artifacts were also applied during interpretation. RESULTS: Using combined SPECT plus CTA as the diagnostic standard, abnormal myocardial CTP was present in 33 (56%) patients, 19 suggesting infarction and 14 suggesting ischemia. Patient-level color and gray-scale myocardial CTP sensitivity to detect infarction was 90%, with specificity 80%, and negative and positive predictive value of 94% and 68%. To detect ischemia or infarction, CTP specificity and positive predictive value were 92% whereas sensitivity was 70%. Gray-scale myocardial CTP had slightly lower specificity but similar sensitivity. Myocardial CTP artifacts were present in 88% of studies and were identified using our criteria. CONCLUSIONS: Color and gray-scale myocardial CTP using resting CTA images identified myocardial infarction with high sensitivity as well as infarction or ischemia with high specificity and positive predictive value without additional testing or radiation. Color and gray-scale CTP had slightly better specificity than gray-scale alone.

Coronary artery aneurysms as seen on multidetector computed tomography angiography.

Coronary artery aneurysms (CAA) are present in 1.4-5.3% of the population (Nichols, Lagana, Parwani. Arch Pathol Lab Med 2008; 132:823-828). While angiography remains the gold standard for evaluating CAAs, multidetector computed tomography angiography (MDCTA) is an emerging way of assessing CAAs (Pahlavan and Niroomand. Clin Cardiol 2006;29:439-443). With the increasing clinical utilization of MDCTA, CAAs are often initially diagnosed using this method. Since MDCTA is used largely in lower risk and asymptomatic patients, understanding the etiology and treatment is paramount for clinicians reading these studies.

Single coronary artery syndrome: cardiac computed tomography angiography as a leading imaging modality.

Single coronary artery syndrome is usually an asymptomatic condition in most patients; thus most patients are diagnosed when noninvasive imaging (cardiac computed tomography angiography, cardiac magnetic resonance) or invasive coronary angiography is done for evaluation for other cardiac conditions. With advances using cardiovascular imaging in the evaluation and management of single coronary artery syndrome; Cardiac Computed Tomography Angiography (CCTA) has emerged as a very essential and leading imaging modality. CCTA has the best resolution (spatial and temporal) among the imaging modalities available for analyzing the cardiovascular system for the diagnosis and management of single coronary artery syndrome. We are presenting cases of patients with single coronary artery syndrome with 3 different courses (anterior, septal, inter-arterial), illustrating how CCTA gives a detailed anatomic/structural evaluation of the origin and course of the coronary arteries, and other cardiac structures. Thus in patients diagnosed with single coronary artery syndrome, CCTA can provide vital information on the not only the course, but the associated narrowing of coronary vessels.

Left ventricular volume: an optimal parameter to detect systolic dysfunction on prospectively triggered 64-multidetector row computed tomography: another step towards reducing radiation exposure.

In this study, we define the correlation between LV volumes (both LV end-diastolic volume [LVEDV] and LV end-systolic volume [LVESV]) and ejection fraction (EF) on 64 slice multi-detector computed tomography (MDCT). We also determine the accuracy of all the LV volume (LVV) parameters to detect LV systolic dysfunction (LVSD) and investigate the feasibility of using LVV as a surrogate of LVSD on prospectively gated imaging to prevent the radiation exposure of retrospective imaging. 568 patients undergoing 64-detector MDCT were divided into 2 groups: Group 1-subjects without any heart disease and LVEF ≥ 50%; and Group 2-patients with coronary artery disease and LVEF < 50% (defined as LVSD). The LVV (LV cavity only) and Total LV volume (cavity + LV mass) at end-systole and end-diastole (LVESV, Total LVESV, LVEDV and Total LVEDV) were measured. The upper limit values (mean + 2 SD) of all LVV parameters in Group 1 were used as the reference criterion to diagnose LVSD in Group 2. An exponential correlation was found between LVEF and all the LVV parameters. The specificity to detect LVSD in Group 2 was >90% and the sensitivity was 88.9, 83.3, 61.3 and 74.9% by using LVESV, Total LVESV, LVEDV and Total LVEDV, respectively. Systolic and diastolic LV volumes had a high correlation with LVEF and a high accuracy to detect LVSD. Thus, on prospectively triggered imaging, ventricular volumes can predict patients with reduced LVEF, and appropriate referrals can be made.

Non-contrast cardiac computed tomography can accurately detect chronic myocardial infarction: Validation study.

BACKGROUND: This study evaluates whether non-contrast cardiac computed tomography (CCT) can detect chronic myocardial infarction (MI) in patients with irreversible perfusion defects on nuclear myocardial perfusion imaging (MPI). METHODS: One hundred twenty-two symptomatic patients with irreversible perfusion defect (N = 62) or normal MPI (N = 60) underwent coronary artery calcium (CAC) scanning. MI on these non-contrast CCTs was visually detected based on the hypo-attenuation areas (dark) in the myocardium and corresponding Hounsfield units (HU) were measured. RESULTS: Non-contrast CCT accurately detected MI in 57 patients with irreversible perfusion defect on MPI, yielding a sensitivity of 92%, specificity of 72%, negative predictive value (NPV) of 90%, and a positive predictive value (PPV) of 77%. On a per myocardial region analysis, non-contrast CT showed a sensitivity of 70%, specificity of 85%, NPV of 91%, and a PPV of 57%. The ROC curve showed that the optimal cutoff value of LV myocardium HU to predict MI on non-contrast CCT was 21.7 with a sensitivity of 97.4% and specificity of 99.7%. CONCLUSION: Non-contrast CCT has an excellent agreement with MPI in detecting chronic MI. This study highlights a novel clinical utility of non-contrast CCT in addition to assessment of overall burden of atherosclerosis measured by CAC.

Central aortic valve coaptation area during diastole as seen by 64-multidetector computed tomography (MDCT).

As multiple new procedures now require better visualization of the aortic valve, we sought to better define the central aortic valve coaptation area seen during diastole on multi-detector row cardiac computed tomography (MDCT). 64-MDCT images of 384 symptomatic consecutive patients referred for coronary artery disease evaluation were included in the study. Planimetric measurements of this area were performed on cross-sectional views of the aortic valve at 75% phase of the cardiac cycle. Planimetric measurement of central regurgitation orifice area (ROA) seen in patients with aortic regurgitation and Hounsfield units of the central aortic valve coaptation area were performed. Mean area of the central aortic valve coaptation area was 5.34 ± 5.19 mm(2) and Hounsfield units in this area were 123.69 ± 31.31 HU. The aortic valve coaptation area (mm(2)) measurement in patients without AR was: 4.90 ± 0.17 and in patients with AR: 10.53 ± 0.26 (P ≤ 0.05). On Bland-Altman analysis a very good correlation between central aortic valve coaptation area and central ROA was found (r = 0.80, P ≤ 0.001). Central aortic valve coaptation area is a central area present at the coaptation of nodules of arantius of aortic cusps during diastole; it is incompetent and increased in size in patients with aortic regurgitation.

A meandering mesenteric artery.

An 83-year-old woman with a history of peripheral vascular disease presented for evaluation of lower left extremity discomfort. A peripheral multidetector CT angiography showed a dilated inferior mesenteric artery acting as an important source of retrograde collateral perfusion secondary to a celiac axis stenosis.

Relation of oxidative biomarkers, vascular dysfunction, and progression of coronary artery calcium.

The relation between oxidative stress and coronary artery calcium (CAC) progression is currently not well described. The present study evaluated the relation among the biomarkers of oxidative stress, vascular dysfunction, and CAC. Sixty asymptomatic subjects participated in a randomized trial evaluating the effect of aged garlic extract plus supplement versus placebo and underwent measurement of CAC. The postcuff deflation temperature-rebound index of vascular function was assessed using a reactive hyperemia procedure. The content of oxidized phospholipids (OxPL) on apolipoprotein B-100 (apoB) particles detected by antibody E06 (OxPL/apoB), lipoprotein(a), IgG and IgM autoantibodies to malondialdehyde-low-density lipoprotein and apoB-immune complexes were measured at baseline and after 12 months of treatment. CAC progression was defined as an annual increase in CAC >15%. Vascular dysfunction was defined according to the tertiles of temperature-rebound at 1 year of follow-up. From baseline to 12 months, a strong inverse correlation was noted between an increase in CAC scores and increases in temperature-rebound (r(2) = -0.90), OxPL/apoB (r(2) = -0.85), and lipoprotein(a) (r(2) = -0.81) levels (p <0.0001 for all). The improvement in temperature-rebound correlated positively with the increases in OxPL/apoB (r(2) = 0.81, p = 0.0008) and lipoprotein(a) (r(2) = 0.79, p = 0.0001) but inversely with autoantibodies to malondialdehyde-low-density lipoprotein and apoB-immune complexes. The greatest CAC progression was noted with the lowest tertiles of increases in temperature-rebound, OxPL/apoB and lipoprotein(a) and the highest tertiles of increases in IgG and IgM malondialdehyde-low-density lipoprotein. In conclusion, the present results have documented a strong relation among markers of oxidative stress, vascular dysfunction, and progression of coronary atherosclerosis. Increases in OxPL/apoB and lipoprotein(a) correlated strongly with increases in vascular function and predicted a lack of progression of CAC.