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.

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.

Clinical Implications of Three-Dimensional Real-Time Color Doppler Transthoracic Echocardiography in Quantifying Mitral Regurgitation: A Comparison with Conventional Two-Dimensional Methods.

BACKGROUND: Automatic quantification of real-time three-dimensional (3D) full-volume color Doppler transthoracic echocardiography (FVCD) has been proposed as a feasible and accurate method for quantifying MR. We aimed to explore the clinical implications of real-time 3D-FVCD for mitral regurgitation (MR) with various clinical manifestations, in comparison with the conventional two-dimensional (2D) proximal isovelocity surface area (PISA) and volumetric method and cardiac magnetic resonance imaging (CMR) methods. METHODS: A total 186 patients with MR were enrolled prospectively. Based on exclusion criteria and image quality review, 152 patients were included in the final analysis for 3D-FVCD and 2D transthoracic echocardiography. Among them, 37 patients underwent subsequent CMR for the validation of 3D-FVCD. RESULTS: MR volume from 3D-FVCD demonstrated a better agreement (r = 0.94) with CMR than 2D-PISA or the 2D volumetric method (VM; r = 0.87 vs 0.56). Overall, 2D methods underestimated MR when compared with 3D-FVCD (35.4 ± 28.4 mL for 2D-VM vs 43.8 ± 24.6 mL for 2D-PISA vs 64.6 ± 35.1 mL for 3D-FVCD; P < .001). In subgroup analysis, multijet MR (odds ratio [OR], 6.30; 95% CI, 2.52-15.72) and dilated left ventricular end-systolic diameter ≥40 mm (OR, 2.90; 95% CI, 1.12-7.50) were predictors of significant difference in MR volume (>30 mL for primary MR and >15 mL for secondary MR) between 2D-PISA and 3D-FVCD. In identifying surgical candidates, patients with multijet MR (OR, 4.53, 95% CI, 1.99-10.35) demonstrated a higher risk of discrepancy between 2D-PISA and 3D-FVCD, which were consistent in both primary and secondary MR, respectively. CONCLUSIONS: MR quantification with 3D-FVCD showed better correlation and agreement than conventional 2D methods. MR was underestimated by 2D methods, especially in multijet and dilated left ventricle. Multijet MR demonstrated higher risk of discrepancy for the identification of surgical candidate, regardless of MR etiology.

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).

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).

Impact of D-Dimer for Prediction of Incident Occult Cancer in Patients with Unprovoked Venous Thromboembolism.

BACKGROUND: Unprovoked venous thromboembolism (VTE) is related to a higher incidence of occult cancer. D-dimer is clinically used for screening VTE, and has often been shown to be present in patients with malignancy. We explored the predictive value of D-dimer for detecting occult cancer in patients with unprovoked VTE. METHODS: We retrospectively examined data from 824 patients diagnosed with deep vein thrombosis or pulmonary thromboembolism. Of these, 169 (20.5%) patients diagnosed with unprovoked VTE were selected to participate in this study. D-dimer was categorized into three groups as: <2,000, 2,000-4,000, and >4,000 ng/ml. Cox regression analysis was employed to estimate the odds of occult cancer and metastatic state of cancer according to D-dimer categories. RESULTS: During a median 5.3 (interquartile range: 3.4-6.7) years of follow-up, 24 (14%) patients with unprovoked VTE were diagnosed with cancer. Of these patients, 16 (67%) were identified as having been diagnosed with metastatic cancer. Log transformed D-dimer levels were significantly higher in those with occult cancer as compared with patients without diagnosis of occult cancer (3.5±0.5 vs. 3.2±0.5, P-value = 0.009, respectively). D-dimer levels >4,000 ng/ml was independently associated with occult cancer (HR: 4.12, 95% CI: 1.54-11.04, P-value = 0.005) when compared with D-dimer levels <2,000 ng/ml, even after adjusting for age, gender, and type of VTE (e.g., deep vein thrombosis or pulmonary thromboembolism). D-dimer levels >4000 ng/ml were also associated with a higher likelihood of metastatic cancer (HR: 9.55, 95% CI: 2.46-37.17, P-value <0.001). CONCLUSION: Elevated D-dimer concentrations >4000 ng/ml are independently associated with the likelihood of occult cancer among patients with unprovoked VTE.

Long-Term Prognosis After Coronary Artery Calcium Scoring Among Low-Intermediate Risk Women and Men.

BACKGROUND: Cardiovascular screening of women using traditional risk factors has been challenging, with results often classifying a majority of women as lower risk than men. The aim of this report was to determine the long-term prognosis of asymptomatic women and men classified at low-intermediate risk undergoing screening with coronary artery calcium (CAC) scoring. METHODS AND RESULTS: A total of 2363 asymptomatic women and men with traditional risk factors aggregating into a low-intermediate Framingham risk score (6%-9.9%; 10-year predicted risk) underwent CAC scanning. Individuals were followed up for a median of 14.6 years. We estimated all-cause mortality using Cox proportional hazards models; hazard ratios with 95% confidence intervals were calculated. The area under the curve from a receiver operating characteristics curve analysis was calculated. There were 1072 women who were older (55.6 years) when compared with the 1291 men (46.7 years; P<0.0001), resulting in a greater prevalence and extent of CAC; 18.8% of women and 15.1% of men had a CAC score ≥100 (P=0.029). This older group of women had a 1.44-fold higher 15-year adjusted mortality hazard when compared with men (P=0.022). For women, the 15-year mortality ranged from 5.0% for those with a CAC score of 0 to 23.5% for those with a CAC score ≥400 (P<0.001). For men, the 15-year mortality ranged from 3.5% for those with a CAC score of 0 to 18.0% for those with a CAC score ≥400 (P<0.001). Women with CAC scores >10 had a higher mortality risk when compared with men. CONCLUSIONS: Our findings extend previous work that CAC effectively identifies high-risk women with a low-intermediate risk factor burden. These data require validation in external cohorts but lend credence to the use of CAC in women to improve risk detection algorithms that are currently based on traditional risk factors.

Dual-energy computed tomography for detection of coronary artery disease.

Recent technological advances in computed tomography (CT) technology have fulfilled the prerequisites for the cardiac application of dual-energy CT (DECT) imaging. By exploiting the unique characteristics of materials when exposed to two different x-ray energies, DECT holds great promise for the diagnosis and management of coronary artery disease. It allows for the assessment of myocardial perfusion to discern the hemodynamic significance of coronary disease and possesses high accuracy for the detection and characterization of coronary plaques, while facilitating reductions in radiation dose. As such, DECT enabled cardiac CT to advance beyond the mere detection of coronary stenosis expanding its role in the evaluation and management of coronary atherosclerosis.

Current trends in patients with chronic total occlusions undergoing coronary CT angiography.

OBJECTIVE: Data describing the prevalence, characteristics and management of coronary chronic total occlusions (CTOs) in patients undergoing coronary CT angiography (CCTA) have not been reported. The purpose of this study was to determine the prevalence, characteristics and treatment strategies of CTO identified by CCTA. METHODS: We identified 23 745 patients who underwent CCTA for suspected coronary artery disease (CAD) from the prospective international CCTA registry. Baseline clinical data were collected, and allocation to early coronary revascularisation performed within 90 days of CCTA was determined. Multivariable hierarchical mixed-effects logistic regression reporting OR with 95% CI was performed. RESULTS: The prevalence of CTO was 1.4% (342/23 745) in all patients and 6.2% in patients with obstructive CAD (≥50% stenosis). The presence of CTO was independently associated with male sex (OR 3.12, 95% CI 2.39 to 4.08, p<0.001), smoking (OR 2.02, 95% CI 1.55 to 2.64, p<0.001), diabetes (OR 1.60, 95% CI 1.22 to 2.11, p=0.001), typical angina (OR 1.51, 95% CI 1.12 to 2.06, p=0.008), hypertension (OR 1.47, 95% CI 1.14 to 1.88, p=0.003), family history of CAD (OR 1.30, 95% CI 1.01 to 1.67, p=0.04) and age (OR 1.06, 95% CI 1.05 to 1.07, p<0.001). Most patients with CTO (61%) were treated medically, while 39% underwent coronary revascularisation. In patients with severe CAD (≥70% stenosis), CTO independently predicted revascularisation by coronary artery bypass grafting (OR 3.41, 95% CI 2.06 to 5.66, p<0.001), but not by percutaneous coronary intervention (p=0.83). CONCLUSIONS: CTOs are not uncommon in a contemporary CCTA population, and are associated with age, gender, angina status and CAD risk factors. Most individuals with CTO undergoing CCTA are managed medically with higher rates of surgical revascularisation in patients with versus without CTO. TRIAL REGISTRATION NUMBER: ClinicalTrials.gov identifier NCT01443637.

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.