Prognostic value of coronary computed tomographic angiography findings in asymptomatic individuals: a 6-year follow-up from the prospective multicentre international CONFIRM study.

Aim: The long-term prognostic benefit of coronary computed tomographic angiography (CCTA) findings of coronary artery disease (CAD) in asymptomatic populations is unknown. Methods and results: From the prospective multicentre international CONFIRM long-term study, we evaluated asymptomatic subjects without known CAD who underwent both coronary artery calcium scoring (CACS) and CCTA (n = 1226). Coronary computed tomographic angiography findings included the severity of coronary artery stenosis, plaque composition, and coronary segment location. Using the C-statistic and likelihood ratio tests, we evaluated the incremental prognostic utility of CCTA findings over a base model that included a panel of traditional risk factors (RFs) as well as CACS to predict long-term all-cause mortality. During a mean follow-up of 5.9 ± 1.2 years, 78 deaths occurred. Compared with the traditional RF alone (C-statistic 0.64), CCTA findings including coronary stenosis severity, plaque composition, and coronary segment location demonstrated improved incremental prognostic utility beyond traditional RF alone (C-statistics range 0.71-0.73, all P < 0.05; incremental χ2 range 20.7-25.5, all P < 0.001). However, no added prognostic benefit was offered by CCTA findings when added to a base model containing both traditional RF and CACS (C-statistics P > 0.05, for all). Conclusions: Coronary computed tomographic angiography improved prognostication of 6-year all-cause mortality beyond a set of conventional RF alone, although, no further incremental value was offered by CCTA when CCTA findings were added to a model incorporating RF and CACS.

Incremental role of resting myocardial computed tomography perfusion for predicting physiologically significant coronary artery disease: A machine learning approach.

BACKGROUND: Evaluation of resting myocardial computed tomography perfusion (CTP) by coronary CT angiography (CCTA) might serve as a useful addition for determining coronary artery disease. We aimed to evaluate the incremental benefit of resting CTP over coronary stenosis for predicting ischemia using a computational algorithm trained by machine learning methods. METHODS: 252 patients underwent CCTA and invasive fractional flow reserve (FFR). CT stenosis was classified as 0%, 1-30%, 31-49%, 50-70%, and >70% maximal stenosis. Significant ischemia was defined as invasive FFR < 0.80. Resting CTP analysis was performed using a gradient boosting classifier for supervised machine learning. RESULTS: On a per-patient basis, accuracy, sensitivity, specificity, positive predictive, and negative predictive values according to resting CTP when added to CT stenosis (>70%) for predicting ischemia were 68.3%, 52.7%, 84.6%, 78.2%, and 63.0%, respectively. Compared with CT stenosis [area under the receiver operating characteristic curve (AUC): 0.68, 95% confidence interval (CI) 0.62-0.74], the addition of resting CTP appeared to improve discrimination (AUC: 0.75, 95% CI 0.69-0.81, P value .001) and reclassification (net reclassification improvement: 0.52, P value < .001) of ischemia. CONCLUSIONS: The addition of resting CTP analysis acquired from machine learning techniques may improve the predictive utility of significant ischemia over coronary stenosis.

Prevalence and Distribution of Coronary Artery Calcification in Asymptomatic United States and Korean Adults　- Cross-Sectional Propensity-Matched Analysis.

BACKGROUND: The incidence of coronary artery disease (CAD) varies depending on ethnicity, but the precise differences remain to be firmly established. This study therefore evaluated the disparity in coronary artery calcification (CAC), as a marker of CAD, in asymptomatic US and Korean adults.Methods and Results:CAC score was compared between asymptomatic Korean (n=15,128) and US (n=7,533) adults. Propensity score matching was performed according to age, gender, hypertension, diabetes, dyslipidemia, and current smoking, which generated 2 cohorts of 5,427 matched pairs. Both cohorts were categorized according to age group: 45-54, 55-64, and 65-74 years. Overall, the prevalence of CAC score >0, >100, and >400 in Korean adults was lower than in US adults (P<0.001, all). According to increasing age groups, the likelihood of CAC was most often lower in Korean adults, especially in Korean women. The odds of having CAC >400 in Korean adults aged 65-74 years was 0.66 (95% CI: 0.48-0.91) overall, 0.78 (95% CI: 0.52-1.19) in men, and 0.50 (95% CI: 0.29-0.86) in women, compared with US counterparts. CONCLUSIONS: Korean adults have a lower prevalence and severity of atherosclerotic burden as assessed on CAC, compared with US adults, but the disparity in CAC according to ethnicity may decline with older age. (Circ J 2016; 80: 2349-2355).

Warranty Period of Zero Coronary Artery Calcium Score for Predicting All-Cause Mortality According to Cardiac Risk Burden in Asymptomatic Korean Adults.

BACKGROUND: The aim of this study was to examine whether zero coronary artery calcium (CAC) score is associated with favorable prognosis of all-cause mortality (ACM) according to a panel of conventional risk factors (RF) in asymptomatic Korean adults.Methods and Results:A total of 48,215 individuals were stratified according to presence/absence of CAC, and the following RF were examined: hypertension, diabetes, current smoking, high low-density lipoprotein cholesterol, and low high-density lipoprotein cholesterol. The RF were summed on composite score as 0, 1-2, or ≥3 RF present. The warranty period was defined as the time to cumulative mortality rate >1%. Across a median follow-up of 4.4 years (IQR, 2.7-6.6), 415 (0.9%) deaths occurred. Incidence per 1,000 person-years for ACM was consistently higher in subjects with any CAC, irrespective of number of RF. The warranty period was substantially longer (eg, 9 vs. 5 years) for CAC=0 compared with CAC >0. The latter observation did not change materially according to pre-specified RF, but difference in warranty period according to presence/absence of CAC reduced somewhat when RF burden increased. CONCLUSIONS: In asymptomatic Korean adults, the absence of CAC evoked a strong protective effect against ACM as reflected by longer warranty period, when no other RF were present. The usefulness of zero CAC score and its warranty period requires further validation in the presence of multiple RF. (Circ J 2016; 80: 2356-2361).

Incremental prognostic utility of coronary CT angiography for asymptomatic patients based upon extent and severity of coronary artery calcium: results from the COronary CT Angiography EvaluatioN For Clinical Outcomes InteRnational Multicenter (CONFIRM) study.

AIM: Prior evidence observed no predictive utility of coronary CT angiography (CCTA) over the coronary artery calcium score (CACS) and the Framingham risk score (FRS), among asymptomatic individuals. Whether the prognostic value of CCTA differs for asymptomatic patients, when stratified by CACS severity, remains unknown. METHODS AND RESULTS: From a 12-centre, 6-country observational registry, 3217 asymptomatic individuals without known coronary artery disease (CAD) underwent CACS and CCTA. Individuals were categorized by CACS as: 0-10, 11-100, 101-400, 401-1000, >1000. For CCTA analysis, the number of obstructive vessels-as defined by the per-patient presence of a ≥50% luminal stenosis-was used to grade the extent and severity of CAD. The incremental prognostic value of CCTA over and above FRS was measured by the likelihood ratio (LR) χ(2), C-statistic, and continuous net reclassification improvement (NRI) for prediction, discrimination, and reclassification of all-cause mortality and non-fatal myocardial infarction. During a median follow-up of 24 months (25th-75th percentile, 17-30 months), there were 58 composite end-points. The incremental value of CCTA over FRS was demonstrated in individuals with CACS >100 (LRχ(2), 25.34; increment in C-statistic, 0.24; NRI, 0.62, all P < 0.001), but not among those with CACS ≤100 (all P > 0.05). For subgroups with CACS >100, the utility of CCTA for predicting the study end-point was evident among individuals whose CACS ranged from 101 to 400; the observed predictive benefit attenuated with increasing CACS. CONCLUSION: Coronary CT angiography provides incremental prognostic utility for prediction of mortality and non-fatal myocardial infarction for asymptomatic individuals with moderately high CACS, but not for lower or higher CACS.

Incremental benefit of coronary artery calcium score above traditional risk factors for all-cause mortality in asymptomatic Korean adults.

BACKGROUND: Coronary artery calcium score (CACS) is a well-recognized marker for subclinical coronary atherosclerosis, particularly in asymptomatic populations. To date, however, the added prognostic benefit of CACS compared with traditional risk factors in an Asian population remains unknown. This study therefore investigated the benefit of CACS over traditional risk factors for all-cause mortality in a large multicenter registry of asymptomatic Korean adults. METHODS AND RESULTS: A total of 34,386 individuals were retrospectively enrolled to participate in a general health examination. The Framingham 10-year risk score (FRS) was calculated according to the traditional risk stratification algorithm and CACS was calculated in log(CACS+1) for continuous data and categorized as 0, 1-100, 101-400 and >400. During a median follow-up of 4.9 years (IQR, 3.0-7.1), there were 303 all-cause deaths (0.9%). Following adjustment, CACS was independently associated with all-cause death (hazard ratio, 1.10; 95% confidence interval (CI): 1.05-1.17; P<0.001). Notably, CACS added further prognostic value above and beyond FRS (likelihood ratio, χ(2)=75.42, P<0.001; continuous net reclassification improvement=0.40, 95% CI: 0.29-0.51, P≤0.001; improving C-statistic from 0.64, 95% CI: 0.61-0.67 to 0.68, 95% CI: 0.64-0.71; ∆C=0.04, 95% CI: 0.01-0.06, P=0.002). CONCLUSIONS: In an asymptomatic Korean population, CACS improved prediction of all-cause mortality over and above that of a conventional risk tool.

Physical activity and resting pulse rate in older adults: findings from a randomized controlled trial.

BACKGROUND: Elevated resting pulse rate (RPR) is a well-recognized risk factor for adverse outcomes. Epidemiological evidence supports the beneficial effects of regular exercise for lowering RPR, but studies are mainly confined to persons younger than 65 years. We set out to evaluate the utility of a physical activity (PA) intervention for slowing RPR among older adults. METHODS: A total of 424 seniors (ages 70-89 years) were randomized to a moderate intensity PA intervention or an education-based "successful aging" health program. Resting pulse rate was assessed at baseline, 6 months, and 12 months. Longitudinal differences in RPR were evaluated between treatment groups using generalized estimating equation models, reporting unstandardized ß coefficients with robust SEs. RESULTS: Increased frequency and duration of aerobic training were observed for the PA group at 6 and 12 months as compared with the successful aging group (P < .001). In both groups, RPR remained unchanged over the course of the 12-month study period (P = .67). No significant improvement was observed (ß [SE] = 0.58 [0.88]; P = .51) for RPR when treatment groups were compared using the generalized estimating equation method. Comparable results were found after omitting participants with a pacemaker, cardiac arrhythmia, or who were receiving ß-blockers. CONCLUSIONS: Twelve months of moderate intensity aerobic training did not improve RPR among older adults. Additional studies are needed to determine whether PA of longer duration and/or greater intensity can slow RPR in older persons.

Evidence of a synergistic association between heart rate, inflammation, and cardiovascular mortality in patients undergoing coronary angiography.

AIMS: Both elevated inflammatory activity and sustained tachycardia reflect unfavourable cardiovascular risk profiles, and there is evidence to suggest the deleterious effects of inflammation are amplified by increased heart rate. The purpose of this study was to assess the interaction between resting heart rate and inflammation in cardiovascular mortality. METHODS AND RESULTS: A total of 3267 patients (2283 men), aged 18-95 years, scheduled for coronary angiography, were followed prospectively. By principle component analysis, we developed an overall multi-marker index of inflammation weighting the respective coefficients of five inflammatory markers including: interleukin-6, C-reactive protein, serum amyloid A, neutrophils, and fibrinogen. Cox proportional hazard regression models were employed to evaluate the relationship between inflammation and heart rate with cardiovascular mortality. Across 29,940 person years of follow-up, there were 546 (17%) deaths due to cardiovascular disease (CVD). Significantly, we observed a strong synergistic effect of inflammatory activity and concurrent elevated heart rate. For CVD mortality, patients in the highest quartile of inflammation had an adjusted hazard ratio (95% confidence interval) of 1.84 (1.31-2.57), P < 0.0001 if their resting heart rate was <75 b.p.m. Substantially, patients had a greater adjusted HR of 7.50 (3.21-17.50), P < 0.0001 if their resting heart rate was ≥75 b.p.m. CONCLUSION: The present analyses underline elevated inflammation as a risk factor for cardiovascular mortality. The effects of inflammation appeared to be strongly amplified by a faster resting heart rate. If confirmed by additional studies, this association may prove a useful adjunct for therapeutic approaches to alleviate symptoms and prolong survival.

Association of 25-hydroxyvitamin D with type 2 diabetes among patients undergoing coronary angiography: cross-sectional findings from the LUdwigshafen Risk and Cardiovascular Health (LURIC) Study.

OBJECTIVE: Evidence suggests that vitamin D may protect against the onset of diabetes. However, the mechanisms underlying the role of vitamin D on glycaemic status are unclear and warrant further investigation. We sought to determine the relationship between serum 25-hydroxyvitamin D (25[OH]D) and glycaemic status among intermediate-to-high-risk patients scheduled for coronary angiography. METHODS: Participants were 3316 male and female patients (mean ± SD age, 62·7 ± 10·6 years). Four categories were formed according to serum 25[OH]D levels. The association between serum 25[OH]D and diabetes was assessed using multivariable logistic regression. RESULTS: Fasting and 2 h post-load glucose, HbA1c and the HOMA-IR indices diminished with increasing serum 25[OH]D levels (P < 0·001). However, no associations were observed between insulin, pro-insulin or C-peptide and serum 25[OH]D concentrations. The pro-inflammatory markers IL-6 and hs-CRP also decreased considerably with higher vitamin D levels (P < 0·001). After full adjustment, those with optimal serum 25[OH]D levels had a reduced odds for fasting diabetes (OR = 0·63; 95% CI, 0·46-0·86; Ptrend = 0·01), 2 h post-load diabetes (OR = 0·46; 95% CI, 0·29-0·74; Ptrend = 0·004), both fasting/2 h post-load diabetes (OR = 0·61; 95% CI, 0·42-0·87; Ptrend = 0·001) and all of the combined hyperglycaemic states (OR = 0·68; 95% CI, 0·52-0·80; Ptrend = 0·01). CONCLUSIONS: Higher serum 25[OH]D levels were associated with better glycaemic status and lower inflammation. Should these observations be confirmed in future studies, vitamin D supplementation may prove a useful adjunct in attenuating the onset of diabetes.

The role of vitamin D deficiency in cardiovascular disease: where do we stand in 2013?

The high worldwide prevalence of vitamin D deficiency is largely the result of low sunlight exposure with subsequently limited cutaneous vitamin D production. Classic manifestations of vitamin D deficiency are linked to disturbances in bone and mineral metabolism, but the identification of the vitamin D receptor in almost every human cell suggests a broader role of vitamin D for overall and cardiovascular health. The various cardiovascular protective actions of vitamin D such as anti-diabetic and anti-hypertensive effects including renin suppression as well as protection against atherosclerosis and heart diseases are well defined in previous experimental studies. In line with this, large epidemiological studies have highlighted vitamin D deficiency as a marker of cardiovascular risk. However, randomized controlled trials (RCTs) on vitamin D have largely failed to show its beneficial effects on cardiovascular diseases and its conventional risk factors. While most prior vitamin D RCTs were not designed to assess cardiovascular outcomes, some large RCTs have been initiated to evaluate the efficacy of vitamin D supplementation on cardiovascular events in the general population. When considering the history of previous disappointing vitamin RCTs in general populations, more emphasis should be placed on RCTs among severely vitamin D-deficient populations who would most likely benefit from vitamin D treatment. At present, vitamin D deficiency can only be considered a cardiovascular risk marker, as vitamin D supplementation with doses recommended for osteoporosis treatment is neither proven to be beneficial nor harmful in cardiovascular diseases.

Independent and combined associations of abdominal obesity and seated resting heart rate with type 2 diabetes among older Chinese: the Guangzhou Biobank Cohort Study.

BACKGROUND: Central obesity and poor physical fitness predict the development of type 2 diabetes and cardiovascular mortality among Caucasian populations. We studied the independent and combined effect of abdominal obesity and seated resting heart rate used as an indicator of physical fitness, on the presence of type 2 diabetes among 30 519 older residents of Guangzhou, Southern China. METHODS: Participants were stratified into four groups, based on the Asian criteria for abdominal obesity (≥90/≥ 80 cm in men/women) and the 75% cut-off point for seated resting heart rate (≥83 beats per min). The association with type 2 diabetes was assessed using multivariable logistic regression. RESULTS: A total of 3777 (12.7%) volunteers were diagnosed with type 2 diabetes, which was independently associated with seated resting heart rate and, in particular, increasing levels of abdominal obesity (p < 0.001). An odds ratio of 3.93 (95% confidence interval = 3.48-4.43) was identified for type 2 diabetes in participants who were obese with a seated resting heart rate ≥ 83 beats per min after adjusting for potential confounders. CONCLUSIONS: Higher seated resting heart rate, a marker of poor physical fitness, independently doubles the risk of type 2 diabetes. The strength of this association is further increased when abdominal obesity is considered.

Toll-like receptor expression on classic and pro-inflammatory blood monocytes after acute exercise in humans.

Monocytes are a heterogeneous group of cells, the relative distribution of which change in peripheral blood following a strenuous bout of aerobic exercise. Monocyte subtypes can be identified in blood based on the cell surface expression of CD14 and CD16: classic (CD14(++bright)/CD16(-negative)) and the CD16(+dim) (CD14(++bright)/CD16(+dim)) and CD16(++bright) (CD14(+dim)/CD16(++bright)) pro-inflammatory subtypes. Whole monocyte population changes in TLR2, TLR4 and HLA.DR expression have previously been documented after acute exercise without accounting for relative changes in monocyte subpopulations, therefore, this study examined their expression on classic and pro-inflammatory monocyte subsets following 45min of treadmill running at 75% VO(2max). Mononuclear cells isolated from the peripheral blood of moderately trained male subjects (n=15) before (PRE), immediately after (POST) and 1h after (1H) exercise were assessed for TLR2, TLR4 and HLA.DR expression on blood monocytes and their subpopulations using three-colour flow cytometry. Compared to PRE, the proportion of CD14+/CD16+ monocytes was 27% greater POST and 49% less at 1H and was associated with changes in the CD16(++bright) pro-inflammatory subtype (p<0.05). TLR2 expression was 12% lower on CD16(+dim) monocytes POST (p<0.05), whereas TLR4 and HLA.DR expression on total monocytes was 12% and 22% lower at 1H, respectively, and was attributed to changes in the classic (p<0.05) and not the pro-inflammatory subsets (p>0.05). We conclude that acute exercise causes localised changes in TLR2, TLR4 and HLA.DR expression within specific blood monocyte subpopulations, and could therefore be occurring at the cellular level. Such alterations might have significant implications for modulation of post-exercise immune surveillance.

Evaluating Cost-Effectiveness Models for Pharmacologic Interventions in Adults with Heart Failure: A Systematic Literature Review.

BACKGROUND: Heart failure (HF) is a well-recognized public health concern and imposes high economic and societal costs. Decision analytic models exist for evaluating the economic ramifications associated with HF. Despite this, studies that appraise these modelling approaches for augmenting best-practice decisions remain scarce. OBJECTIVE: Our objective was to conduct a systematic literature review (SLR) of published economic models for the management of HF and describe their general and methodological features. METHODS: This SLR employed a combination of relevant search terms associated with HF, which were used in a number of databases, including MEDLINE, Embase, the National Health Service Economic Evaluation Database, Cost-Effectiveness Analysis Registry, ScHARR Health Utilities Database and Cochrane Library Database. A number of model features (i.e. model structure, specification, outcomes assessed, scenario and sensitivity analysis, key model drivers) were extracted and subsequently summarized. RESULTS: Of 64 publications retained, a selection of modelling approaches were identified, including Markov (n = 28), trial-based analytic (n = 22), discrete-event simulation (n = 6), survival analytic (n = 7) and decision-tree modelling (n = 1) approaches. The bulk of publications employed either a cost-utility (n = 27) or cost-effectiveness (n = 36) analysis and evaluated more than one study outcome, which typically included overall costs (n = 59), incremental cost-effectiveness ratios (n = 55), life-years gained (n = 48) and willingness-to-pay thresholds (n = 37). Most publications focused on patients with chronic HF (n = 40) and used New York Heart Association (NYHA) disease classifications to categorize patients and determine disease severity. Few (n = 19) publications documented the use of hospitalization states for modelling patient outcomes and associated costs. A quality assessment of the included publications revealed most articles demonstrated reasonable methodological value. CONCLUSIONS: We identified numerous decision analytic modelling approaches for evaluating the cost effectiveness of pharmacologic treatments in HF. A Markov cohort model approach was most commonly used, and most models relied on NYHA classes as a proxy of HF severity, disease progression and prognosis.

A Comparison of the Updated Diamond-Forrester, CAD Consortium, and CONFIRM History-Based Risk Scores for Predicting Obstructive Coronary Artery Disease in Patients With Stable Chest Pain: The SCOT-HEART Coronary CTA Cohort.

OBJECTIVES: This study sought to compare the performance of history-based risk scores in predicting obstructive coronary artery disease (CAD) among patients with stable chest pain from the SCOT-HEART study. BACKGROUND: Risk scores for estimating pre-test probability of CAD are derived from referral-based populations with a high prevalence of disease. The generalizability of these scores to lower prevalence populations in the initial patient encounter for chest pain is uncertain. METHODS: We compared 3 scores among patients with suspected CAD in the coronary computed tomographic angiography (CTA) randomized arm of the SCOT-HEART study for the outcome of obstructive CAD by coronary CTA: the updated Diamond-Forrester score (UDF), CAD Consortium clinical score (CAD2), and CONFIRM risk score (CRS). We tested calibration with goodness-of-fit, discrimination with area under the receiver-operating curve (AUC), and reclassification with net reclassification improvement (NRI) to identify low-risk patients. RESULTS: In 1,738 patients (age 58 ± 10 years and 44.0% women), overall calibration was best for UDF, with underestimation by CRS and CAD2. Discrimination by AUC was highest for CAD2 at 0.79 (95% confidence interval [CI]: 0.77 to 0.81) than for UDF (0.77 [95% CI: 0.74 to 0.79]) or CRS (0.75 [95% CI: 0.73 to 0.77]) (p < 0.001 for both comparisons). Reclassification of low-risk patients at the 10% probability threshold was best for CAD2 (NRI 0.31, 95% CI: 0.27 to 0.35) followed by CRS (NRI 0.21, 95% CI: 0.17 to 0.25) compared with UDF (p < 0.001 for all comparisons), with a consistent trend at the 15% threshold. CONCLUSIONS: In this multicenter clinic-based cohort of patients with suspected CAD and uniform CAD evaluation by coronary CTA, CAD2 provided the best discrimination and classification, despite overestimation of obstructive CAD as evaluated by coronary CTA. CRS exhibited intermediate performance followed by UDF for discrimination and reclassification.

Achieving target SBP for lowering the risk of major adverse cardiovascular events in persons with diabetes mellitus.

AIM: To test the efficacy of achieving target SBP less than 120 mmHg, or less than 140 mmHg, for lowering the risk of major adverse cardiovascular events (MACE) in persons with diabetes mellitus. METHOD: The study comprised 4732 [mean ±â€ŠSD age: 63 ±â€Š7 years; 2258 (48%) women] persons with advanced diabetes mellitus. Participants randomly assigned to achieve intensive (<120 mmHg) or standard (<140 mmHg) SBP control were grouped according to whether or not they achieved their respective SBP goal. MACE consisted of nonfatal myocardial infarction, nonfatal stroke, and death from cardiovascular causes. RESULTS: During a median 5.0 (interquartile range: 4.2-5.7) years, 1939 (82%) and 2038 (86%) persons achieved SBP targets less than 120 and less than 140 mmHg in each treatment arm, respectively. Overall, 208 (9%) and 237 (10%) persons in the intensive and standard treatment arms experienced MACE. In the intensive treatment arm, multivariable Cox regression revealed no significant reduction in risk of MACE for those who achieved a target SBP less than 120 mmHg. In the standard treatment arm, those who achieved a target SBP less than 140 mmHg displayed a substantial reduction in risk of MACE (hazard ratio = 0.65, P = 0.005), all-cause death (hazard ratio = 0.64, P = 0.02), and nonfatal stroke (hazard ratio = 0.47, P = 0.02) as compared with those whose achieved SBP was 140 mmHg or higher. CONCLUSION: Achieving a standard SBP goal between 120 and 140 mmHg may prove useful for lowering cardiovascular risk in persons with diabetes mellitus. Achieving a target SBP less than 120 mmHg does not appear to mitigate risk. CLINICAL TRIAL REGISTRATION: ClinicalTrials.gov # NCT00000620 (https://clinicaltrials.gov/ct2/results?term=NCT00000620&Search=Search).

Comparative diagnostic accuracy of dual-energy CT myocardial perfusion imaging by monochromatic energy versus material decomposition methods.

PURPOSE: To compare the diagnostic value of monochromatic and material decomposition (MD) dual- energy computed tomography (DECT) imaging for the evaluation of ischemia. METHODS: Patients with suspected coronary artery disease underwent rest-stress DECT and SPECT perfusion imaging. DECT images were reconstructed between 40 and 140keV and through MD of iodine/muscle. RESULTS: MD and monochromatic imaging had a sensitivity, specificity, negative predictive, positive predictive value, and accuracy of 89%, 40%, 67%, 73% and 71%; and 91%, 67%, 67%, 91% and 86%, respectively (p=0.05). CONCLUSION: DECT using monochromatic energy displayed a non-significantly higher diagnostic accuracy for myocardial ischemia as compared with DECT MD.

Geometric predictors of left ventricular outflow tract obstruction in patients with hypertrophic cardiomyopathy: a 3D computed tomography analysis.

Aims: To establish geometric predictors of left ventricular outflow tract obstruction (LVOTO) in hypertrophic cardiomyopathy (HCM) patients by use of cardiac computed tomography (CT). Methods and results: A total of 141 consecutive patients with HCM who underwent cardiac CT comprised the analytic sample. The degree, pattern, and extent of left ventricular (LV) hypertrophy were evaluated using 3D CT. Abnormality of papillary muscle (PM), mitral valve, and aorto-mitral angle were evaluated quantitatively. Multivariable logistic regression analysis and sensitivity analysis were performed to reliably identify predictors of LVOTO. LVOTO was present among 40 (28.4%) patients. Those with LVOTO displayed a higher prevalence for having a spiral pattern of LV hypertrophy (e.g. 51 vs. 16%, P < 0.001), a longer anterior mitral leaflet (AML) length (e.g. 18.0 vs. 15.6 mm, P = 0.007), and a longer distance from lateral PM base to LV apex (e.g. 26.4 vs. 22.0 mm, P < 0.001), as compared with the non-LVOTO group. Multivariable logistic regression revealed all three variables [i.e. spiral pattern (95% confidence interval (CI), 3.75, 1.59-8.84); AML length (95% CI, 1.20, 1.03-1.40); the distance between lateral PM base and LV apex (95% CI, 1.09, 1.01-1.19)] retained significance after adjustment for numerous covariates. Conclusion: Spiral pattern of LV hypertrophy, the length of AML, and the distance between lateral PM base and LV apex were independent predictors of LVOTO in patients with HCM.

Development and Validation of a Simple-to-Use Nomogram for Predicting 5-, 10-, and 15-Year Survival in Asymptomatic Adults Undergoing Coronary Artery Calcium Scoring.

OBJECTIVES: The purpose of this study was to develop and validate a simple-to-use nomogram for prediction of 5-, 10-, and 15-year survival among asymptomatic adults. BACKGROUND: Simple-to-use prognostication tools that incorporate robust methods such as coronary artery calcium scoring (CACS) for predicting near-, intermediate- and long-term mortality are warranted. METHODS: In a consecutive series of 9,715 persons (mean age: 53.4 ± 10.5 years; 59.3% male) undergoing CACS, we developed a nomogram using Cox proportional hazards regression modeling that included: age, sex, smoking, hypertension, dyslipidemia, diabetes, family history of coronary artery disease, and CACS. We developed a prognostic index (PI) summing the number of risk points corresponding to weighted covariates, which was used to configure the nomogram. Validation of the nomogram was assessed by discrimination and calibration applied to a separate cohort of 7,824 adults who also underwent CACS. RESULTS: A total of 936 and 294 deaths occurred in the derivation and validation sets at a median follow-up of 14.6 years (interquartile range: 13.7 to 15.5 years) and 9.4 years (interquartile range: 6.8 to 11.5 years), respectively. The developed model effectively predicted 5-, 10-, and 15-year probability of survival. The PI displayed high discrimination in the derivation and validation sets (C-index 0.74 and 0.76, respectively), indicating suitable external performance of our nomogram model. The predicted and actual estimates of survival in each dataset according to PI quartiles were similar (though not identical), demonstrating improved model calibration. CONCLUSIONS: A simple-to-use nomogram effectively predicts 5-, 10- and 15-year survival for asymptomatic adults undergoing screening for cardiac risk factors. This nomogram may be considered for use in clinical care.

Diagnostic Performance of Hybrid Cardiac Imaging Methods for Assessment of Obstructive Coronary Artery Disease Compared With Stand-Alone Coronary Computed Tomography Angiography: A Meta-Analysis.

OBJECTIVES: The current meta-analysis aimed to evaluate the diagnostic performance of hybrid cardiac imaging techniques compared with stand-alone coronary computed tomography angiography (CTA) for assessment of obstructive coronary artery disease (CAD). BACKGROUND: The usefulness of coronary CTA for detecting obstructive CAD remains suboptimal at present. Myocardial perfusion imaging encompasses positron emission tomography, single-photon emission computed tomography, and cardiac magnetic resonance, which permit the identification of myocardial perfusion defects to detect significant CAD. A hybrid approach comprising myocardial perfusion imaging and coronary CTA may improve diagnostic performance for detecting obstructive CAD. METHODS: PubMed and Web of Knowledge were searched for relevant publications between January 1, 2000 and December 31, 2015. Studies using coronary CTA and hybrid imaging for diagnosis of obstructive CAD (a luminal diameter reduction of >50% or >70% by invasive coronary angiography) were included. In total, 12 articles comprising 951 patients and 1,973 vessels were identified, and a meta-analysis was performed to determine pooled sensitivity, specificity, and summary receiver-operating characteristic curves. RESULTS: On a per-patient basis, the pooled sensitivity of hybrid imaging was comparable to that of coronary CTA (91% vs. 90%; p = 0.28). However, specificity was higher for hybrid imaging versus coronary CTA (93% vs. 66%; p < 0.001). On a per-vessel basis, sensitivity for hybrid imaging against coronary CTA was comparable (84% vs. 89%; p = 0.29). Notably, hybrid imaging yielded a specificity of 95% versus 83% for coronary CTA (p < 0.001). Summary receiver-operating characteristic curves displayed improved discrimination for hybrid imaging beyond coronary CTA alone, on a per-vessel basis (area under the curve: 0.97 vs. 0.93; p = 0.047), although not on a per-patient level (area under the curve: 0.97 vs. 0.93; p = 0.132). CONCLUSIONS: Hybrid cardiac imaging demonstrated improved diagnostic specificity for detection of obstructive CAD compared with stand-alone coronary CTA, yet improvement in overall diagnostic performance was relatively limited.

Quantitative measurement of lipid rich plaque by coronary computed tomography angiography: A correlation of histology in sudden cardiac death.

BACKGROUND AND AIMS: Recent advancements in coronary computed tomography angiography (CCTA) have allowed for the quantitative measurement of high-risk lipid rich plaque. Determination of the optimal threshold for Hounsfield units (HU) by CCTA for identifying lipid rich plaque remains unknown. We aimed to validate reliable cut-points of HU for quantitative assessment of lipid rich plaque. METHODS: 8 post-mortem sudden coronary death hearts were evaluated with CCTA and histologic analysis. Quantitative plaque analysis was performed in histopathology images and lipid rich plaque area was defined as intra-plaque necrotic core area. CCTA images were analyzed for quantitative plaque measurement. Low attenuation plaque (LAP) was defined as any pixel < 30, 45, 60, 75, and 90 HU cut-offs within a coronary plaque. The area of LAP was calculated in each cross-section. RESULTS: Among 105 cross-sections, 37 (35.2%) cross-sectional histology images contained lipid rich plaque. Although the highest specificity for identifying lipid rich plaque was shown with <30 HU cut-off (88.2%), sensitivity (e.g. 55.6% for <75 HU, 16.2% for <30 HU) and negative predictive value (e.g. 75.9% for <75 HU, 65.9% for <30 HU) tended to increase with higher HU cut-offs. For quantitative measurement, <75 HU showed the highest correlation coefficient (0.292, p = 0.003) and no significant differences were observed between lipid rich plaque area and LAP area between histology and CT analysis (Histology: 0.34 ±â€¯0.73 mm2, QCT: 0.37 ±â€¯0.71 mm2, p = 0.701). CONCLUSIONS: LAP area by CCTA using a <75 HU cut-off value demonstrated high sensitivity and quantitative agreement with lipid rich plaque area by histology analysis.