Quantitative and Qualitative Coronary Plaque Assessment Using Computed Tomography Coronary Angiography: A Comparison With Intravascular Ultrasound.

BACKGROUND: To compare computed tomography coronary angiography (CTCA) with intravascular ultrasound (IVUS) in quantitative and qualitative plaque assessment. METHODS: Patients who underwent IVUS and CTCA within 3 months for suspected coronary artery disease were retrospectively studied. Plaque volumes on CTCA were quantified manually and with automated-software and were compared to IVUS. High-risk plaque features were compared between CTCA and IVUS. RESULTS: There were 769 slices in 32 vessels (27 patients). Manual plaque quantification on CTCA was comparable to IVUS per slice (mean difference of 0.06±0.07, p=0.44; Bland-Altman 95% limits of agreement -2.19-2.08 mm3, bias of -0.06mm3) and per vessel (3.1mm3 ± -2.85mm3, p=0.92). In contrast, there was significant difference between automated-software and IVUS per slice (2.3±0.09mm3, p<0.001; 95% LoA -6.78 to 2.25mm3, bias of -2.2mm3) and per vessel (33.04±10.3 mm3, p<0.01). The sensitivity, specificity, positive and negative predictive value of CTCA to detect plaques that had features of echo-attenuation on IVUS was 93.3%, 99.6%, 93.3% and 99.6% respectively. The association of ≥2 high-risk plaque features on CTCA with echo attenuation (EA) plaque features on IVUS was excellent (86.7%, 99.6%, 92.9% and 99.2%). In comparison, the association of high-risk plaque features on CTCA and plaques with echo-lucency on IVUS was only modest. CONCLUSION: Plaque volume quantification by manual CTCA method is accurate when compared to IVUS. The presence of at least two high-risk plaque features on CTCA is associated with plaque features of echo attenuation on IVUS.

Application of the DILEMMA score to improve lesion selection for invasive physiological assessment.

OBJECTIVES: We sought to assess the validity of the DILEMMA score against instantaneous wave-free ratio (iFR) and evaluate its utility in rationalizing the number of patients referred for invasive physiological assessment. BACKGROUND: The DILEMMA score is a validated angiographic scoring tool incorporating minimal lumen diameter, lesion length and subtended myocardial area that has been shown to predict the functional significance of lesions as assessed by fractional flow reserve (FFR). METHODS: Patients in the DEFINE-FLAIR study who had coronary stenosis of intermediate severity were randomized to either FFR or iFR. DILEMMA score was calculated retrospectively on a subset of this cohort by operators blinded to FFR or iFR values. RESULTS: Three hundred and forty-six lesions (181 assessed by FFR; 165 by iFR) from 259 patients (mean age 66.0 years, 79% male) were included. A DILEMMA score ≤ 2 had a negative predictive value of 96.3% and 95.7% for identifying lesions with FFR >0.80 and iFR >0.89, respectively. A DILEMMA score ≥ 9 had a positive predictive value of 88.9% and 100% for identifying lesions with FFR ≤0.80 and iFR ≤0.89, respectively. The receiver operating characteristic area under the curve values for DILEMMA score to predict FFR ≤0.80 and iFR ≤0.89 were 0.83 (95% CI 0.77-0.90) and 0.82 (0.75-0.89) respectively. A DILEMMA score ≤ 2 or ≥9 occurred in 172 of the 346 lesions (49.7%). CONCLUSIONS: Using DILEMMA score in patients with coronary stenosis of intermediate severity may reduce the need for pressure wire use, offering potential cost-savings and minimizing the risks associated with invasive physiological lesion assessment.

Diagnostic accuracy of ASLA score (a novel CT angiographic index) and aggregate plaque volume in the assessment of functional significance of coronary stenosis.

BACKGROUND: Visual assessment of diameter-stenosis on Computed Tomography Coronary Angiography (CTCA) lacks specificity to determine functional significance of coronary artery stenosis. Percent-aggregate plaque volume (%APV) and ASLA score, which incorporates Area of Stenosis, Lesion length, and area of myocardium subtended estimated by APPROACH score (Alberta Provincial Project for Outcome Assessment in Coronary Heart Disease) have been described to predict lesion specific ischaemia in focal lesions with intermediate stenosis. METHODS AND RESULTS: Included were 81 patients (mean age 64.7 ±â€¯9 years, 62% male; 94 vessels) who underwent 320- detector-row CTCA, invasive coronary angiography and fractional-flow-reserve (FFR). We examined vessels with wide range of diameter stenosis (mid to severe) and with multiple lesions. Invasive FFR of ≤0.8 was considered functionally significant. The first 54 patients (62 vessels) formed the derivation cohort. ASLA score was the best predictor of FFR ≤ 0.8 (AUC 0.83, p < 0.001) compared to %APV (0.72), CT >50% (0.76), APPROACH score (0.79), area-stenosis (0.73), diameter-stenosis (0.74), minimum-luminal-diameter (0.74), minimal-luminal-area (0.72), and lesion-length (0.67). ASLA score and not %APV, provided incremental predictive value when added to CT > 50 [(NRI 0.71, p = 0.005) vs. (NRI 0.01, p = 0.96)]. In the validation cohort of 27 patients (32 vessels), the ASLA score (AUC 0.85) was again a better predictor of FFR ≤ 0.8 compared to %APV (0.71), CT > 50% (0.66) and other CT indices. The AUC of ASLA score was superior to CTCA>50% (p = 0.001). CONCLUSION: ASLA score is a novel predictor of functional significance of coronary stenosis and adds incremental predictive value to CT > 50 but %APV did not.

Coronary computed tomography angiography for the assessment of chest pain: current status and future directions.

Chest pain is one of the most common presenting symptoms leading to presentation to medical clinics and Emergency Departments worldwide. Defining the nature and etiology of chest pain can pose a diagnostic dilemma for clinicians, despite the availability of several diagnostic algorithms and guidelines to assist them in evaluating these patients. Most investigations in patients with acute chest pain are initially performed to either exclude or diagnose and manage potentially life-threatening conditions such as acute coronary syndrome, pulmonary embolism and aortic dissection. In cases of stable chest pain syndromes, the focus shifts to determining the presence, extent and severity of coronary artery disease. In recent years, coronary computed tomography angiography (CCTA) is being increasingly used worldwide in the assessment of both stable and acute chest pain syndromes. This review evaluates the current evidence regarding the clinical utility of CCTA in the stable and acute chest pain settings and outlines the latest advances in CCTA techniques, including functional assessment of coronary stenoses, and their potential clinical application to improve patient care in a cost-effective manner.

Assessment of the geometric interaction between the Lotus transcatheter aortic valve prosthesis and the native ventricular aortic interface by 320-multidetector computed tomography.

OBJECTIVES: This study sought to assess the geometric interaction between the Lotus Valve System transcatheter aortic prosthesis (Boston Scientific, Natick, Massachusetts) and the native aortoventricular interface using multidetector computed tomography (MDCT). BACKGROUND: The interaction between transcatheter aortic valve prostheses and native anatomy is variable, although potentially predictable. The Lotus transcatheter device uses a novel mechanical means of expansion, the effect of which on native anatomic geometry has not previously been described. METHODS: Forty patients treated with the Lotus prosthesis were enrolled. The patients underwent 320-MDCT imaging before and after implantation. Prosthesis dimensions and relevant interaction parameters, including circularity and expansion, were assessed. The degree of paraprosthetic regurgitation (PAR) and prosthesis gradient were measured by transthoracic echocardiography at the same time points. RESULTS: The mean baseline annular eccentricity index (EI) was 0.21 ± 0.06 and left ventricular outflow tract EI was 0.31 ± 0.09. The deployed prostheses had high rates of circularity with a mean EI across all device segments of 0.06 ± 0.04. In noncircular device deployment, an EI >0.1 was identified in 25% of prostheses and was associated with greater native annular eccentricity at baseline compared with circular devices (0.24 ± 0.04 vs. 0.19 ± 0.06; p = 0.01). The median percent of expansion was 97.5 ± 3.8% in the inflow portion of the prosthesis. Twenty-five percent of prostheses were <90% expanded in at least 1 segment with a numerical, but not statistically significant, association between oversizing and underexpansion. No correlation was found between device underexpansion and the mean transprosthesis gradient or between noncircularity and PAR. CONCLUSIONS: The Lotus prosthesis results in nearly full device expansion and circularization of the native basal plane. Awareness of the anatomic interaction between this unique device and the native architecture may help in the formulation of appropriate device-specific sizing algorithms.

Comparison of diagnostic accuracy of combined assessment using adenosine stress computed tomography perfusion + computed tomography angiography with transluminal attenuation gradient + computed tomography angiography against invasive fractional flow reserve.

OBJECTIVES: The goal of this study was to compare the diagnostic accuracy of combined computed tomography perfusion (CTP) + computed tomography angiography (CTA), transluminal attenuation gradient by 320-detector row computed tomography (TAG320) + CTA, and CTP + TAG320 + CTA (multidetector computed tomography-integrated protocol [MDCT-IP]) assessment in predicting significant fractional flow reserve (FFR). BACKGROUND: CTA has limited specificity for predicting functionally significant stenoses. Novel CT techniques, including adenosine stress CTP and TAG320, may improve the diagnostic accuracy of CTA. METHODS: CTA, CTP, and TAG320 were assessed using 320-detector row MDCT. Patients who underwent CTA, CTP, and FFR assessment on invasive coronary angiography were included. CTP was assessed using the visual perfusion assessment. TAG320 was defined as the linear regression coefficient between luminal attenuation and axial distance. A TAG320 cutoff value of -15.1 HU/10 mm as previously described was defined as significant. Functionally significant coronary stenosis was defined as FFR ≤0.8. RESULTS: The cohort included 75 patients (age 64.1 ± 10.8 years, 52 men) and 44 (35%) FFR-significant vessels. In 127 vessels, CTA predicted FFR-significant stenosis with 89% sensitivity and 65% specificity compared with MDCT-IP, which showed 88% sensitivity and 83% specificity. In 97 vessels in which the results of all techniques were available, TAG320 + CTA (area under the curve [AUC] = 0.844) and CTP + CTA (AUC = 0.845) had comparable per-vessel diagnostic accuracy (p = 0.98). The diagnostic accuracy of MDCT-IP (AUC = 0.91) was superior to TAG320 + CTA or CTP + CTA (p = 0.01). CONCLUSIONS: In vessels without significant calcification or artefact, TAG320 + CTA and CTP + CTA provide comparable diagnostic accuracy for functional assessment of coronary artery stenosis. MDCT-IP may provide the best diagnostic accuracy for functional assessment of coronary artery stenosis.

Current and evolving clinical applications of multidetector cardiac CT in assessment of structural heart disease.

Multidetector computed tomography (CT) has an established role in the evaluation of selected patients suspected of having coronary disease; however, in addition to coronary assessment, multidetector CT can be used to evaluate numerous noncoronary structures in the same examination. In particular, the use of multidetector CT to provide pulmonary and cardiac venous anatomic information prior to electrophysiology procedures is well established, and its important role in the periprocedural evaluation of patients undergoing percutaneous procedures, such as transcatheter aortic valve replacement and left atrial appendage device occlusion, is being increasingly recognized. Such advances have resulted in multidetector CT being increasingly used as a complementary imaging technique to echocardiography and magnetic resonance imaging for the comprehensive evaluation of cardiac structure and function in particular clinical situations. This review provides an overview of the noncoronary cardiac structures that can be evaluated with multidetector CT, and outlines the established appropriate clinical uses of multidetector CT in the assessment of structural heart disease, as well as evolving periprocedural clinical applications.

Assessment of left ventricular volumes, ejection fraction and regional wall motion with retrospective electrocardiogram triggered 320-detector computed tomography: a comparison with 2D-echocardiography.

Left ventricular (LV) volumes, ejection fraction (LVEF) and regional wall motion (LVRWM) have important treatment and prognostic implications in patients with coronary artery disease. We sought to determine the accuracy of 320-row multidetector computed tomography (MDCT) for the assessment of LV volumes, LVEF and LVRWM, using 2D-echocardiography as the reference standard. We evaluated 50 consecutive patients (mean age 60 ± 14 years, 66% male) who underwent 320-detector MDCT (dose-modulated retrospective electrocardiogram-triggering) and 2D-echocardiography within 14 days for investigation of known or suspected coronary artery disease. Two blinded readers measured LV volumes on MDCT and visually assessed LVRWM with a 3-point scale using a 17-segment model. A separate experienced echocardiologist, blinded to MDCT findings, assessed LVRWM on 2D-echocardiograms and determined LV volumes and LVEF using Simpson's biplane method. 2D-echocardiography served as the reference standard. Mean LVEF was 59 ± 9% (range 26-75%) on 2D-echocardiography and 60 ± 9% (range 27-76%) on MDCT. Using linear regression analysis, MDCT agreed very well with 2D-echocardiography for assessment of LVEDV (r(2) = 0.88; P < 0.001), LVESV (r(2) = 0.95; P < 0.001) and LVEF (r(2) = 0.90; P < 0.001). Mean differences (±standard deviation) of 14 ± 13 ml, 5 ± 7 ml and 1 ± 3% were observed between MDCT and 2D-echocardiography for LVEDV, LVESV and LVEF, respectively. On 2D-echocardiography, 81/850 (9.5%) segments had abnormal LVRWM. Agreement for assessment of LVRWM between 2D-echocardiography and MDCT was excellent (96%, k = 0.76). Accurate assessment of LV volumes, LVEF and LVRWM is feasible with 320-detector MDCT, with MDCT demonstrating slightly larger LV volumes than 2D-echocardiography.

Prehospital 12-lead ECG to triage ST-elevation myocardial infarction and emergency department activation of the infarct team significantly improves door-to-balloon times: ambulance Victoria and MonashHEART Acute Myocardial Infarction (MonAMI) 12-lead ECG project.

BACKGROUND: American College of Cardiology/American Heart Association guidelines recommend >75% of patients with an ST-elevation myocardial infarction receive primary percutaneous coronary interventions (PPCI) within 90 minutes. Despite these recommendations, this goal has been difficult to achieve. METHODS AND RESULTS: We conducted a prospective interventional study involving 349 patients undergoing PPCI at a single tertiary referral institution to determine the impact of prehospital 12-lead ECG triage and emergency department activation of the infarct team on door-to-balloon time (D2BT). The median D2BT of all patients (n=107) who underwent PPCI after field ECG and emergency department activation of the infarct team (MonashHEART Acute Myocardial Infarction [MonAMI] group) was 56 minutes (interquartile range, 36.5 to 70) compared with the median time of a contemporary group (n=122) undergoing PPCI during the same period but not receiving field triage (non-MonAMI group) of 98 minutes (73 to 126.45). The median D2BT time of 120 consecutive patients who underwent PPCI before initiation of the project (pre-MonAMI group) was 101.5 minutes (72.5 to 134; P<0.001). The proportion of patients who achieved a D2BT of < or = 90 minutes increased from 39% in the pre-MonAMI group and 45% in the non-MonAMI group to 93% in the MonAMI group (P<0.001). CONCLUSIONS: The performance of prehospital 12-lead ECG triage and emergency department activation of the infarct team significantly improves D2BT and results in a greater proportion of patients achieving guideline recommendations.

In vivo and in vitro assessment of human saphenous vein wall changes.

PURPOSE: To investigate if noradrenaline (NA) and 5-hydroxyptamine (5-HT) drugs induce responses of isolated control and varicose veins are altered by removal of the endothelium. SUBJECTS #ENTITYSTARTX00026; METHODS: Specimens of the great saphenous vein (GSV) were obtained from 12 subjects with primary varicose veins and 12 subjects from donor vessels at cardiac surgery. A total of 10 normal healthy volunteers were selected for comparison. The diameter changes of GSV during the resting phase, at the end of 5 minutes occlusion, and then every 30 seconds post deflation for five minutes were measured using B-mode ultrasound. Post-surgery the vein sample was collected in a tube of Krebs-Henseleit solution. RESULTS: The repeated measure ANOVA test for the diameter, percent, and difference changes of GSV diameter from maximum diameter at different time intervals showed significance difference within and between all groups. NA and 5-HT produced concentration-dependent contractions of control and varicose saphenous vein segments. There was no significant difference in the potency of NA and for 5-HT, but the maximum response, normalized for tissue weight, was less in varicose vein segments. Removal of the endothelium had no effect on the potency of NA or 5-HT but significantly (p<0.05) reduced the maximum response to NA and 5-HT in varicose vein segments but not to 5-HT in control veins. CONCLUSION: The venous endothelial damage may cause vascular smooth muscle contractions dysfunction that favours dilatation and secondary valvular insufficiency.