Multidetector Cardiac CT Research Articles

Prosthetic Aortic Valve Thrombosis.

Prosthetic valve thrombosis is the second leading cause of prosthetic valve deterioration and is being more readily diagnosed with the use of echocardiography and multidetector cardiac CT. Presentation of valve thrombosis can be acute or subacute and any change in clinical status of a patient with a prosthetic valve should raise a suspicion of prosthetic valve thrombosis. Diagnosis entails detailed clinical examination and comprehensive imaging. The choice of therapeutic options includes anticoagulation, fibrinolytic therapy, or valve replacement. Antiplatelet and anticoagulation therapy remain the mainstay of thrombosis prevention in patients with a prosthetic valve and a personalized approach is required to optimize prosthetic valve function and minimize the risk of bleeding.

Left ventricular outflow tract obstruction after transcatheter mitral valve replacement: the importance of preprocedural planning and prevention

Given the prevalence of mitral valve pathology in high-risk patients, transcatheter mitral valve replacement (TMVR) is becoming an attractive treatment modality. A known complication of TMVR is left ventricular outflow tract obstruction (LVOT) due to the prosthetic mitral valve and native anterior mitral valve leaflet encroaching into the LVOT. This is a serious complication which can lead to decreased cardiac output and death. Preprocedural planning with various imaging modalities (multi-detector cardiac CT and echocardiography) can predict those at high risk of LVOT obstruct. To increase awareness and to prevent this complication from occurring in the future, we present a case of LVOT obstruction after TMVR.

Application of trans-thoracic echocardiography and coronary CT angiography to diagnose mitral valve prolapse

ObjectiveAt present, multi-detector cardiac CT has been widely applied in the detection of heart valve morphology and function. This study aims to compare the coronary CT angiography and trans-thoracic echocardiography for patients with mitral valve prolapse.MethodsCT angiography and trans-thoracic echocardiography were adopted to detect the movement range and thickness of valvula bicuspidalis. The ultrasonic parameters of CT angiography were considered as standard reference value.ResultsReceiver operating characteristic (ROC) curve showed that the area of mitral valve motion amplitude under ROC curve was 95% detected by CT angiography with statistical significance (P < 0.001). Based on the intercept point on the ROC curve, the sensitivity and accuracy of mitral valve amplitude detected by CT angiography was 69.2 and 95.6%, the false positive and false negative rate was 5.2 and 32.4%, the predicted value of positive and negative was 92.9 and 76.9% and the consistency rate of motion range and leaf thickness detected by CT angiography was 83.3 and 47.5%. Trans-thoracic echocardiography showed that the thickness and motion range of mitral leaflet was (1.95 ± 0.22) mm and (1.5 ± 2.28) mm. The thickness and motion range of mitral leaflet that detected by CT was (2.00 ± 0.54) mm and (3.76 ± 2.1) mm.ConclusionThe accuracy and reliability of CT angiography for patients with mitral valve prolapse are higher than those of trans-thoracic echocardiography.

Aortic root, not valve, calcification correlates with coronary artery calcification in patients with severe aortic stenosis: A two-center study

BackgroundThe underlying pathology in aortic stenosis (AS) and coronary artery stenosis (CAS) is similar including atherosclerosis and calcification. We hypothesize that coronary artery calcification (CAC) is likely to correlate with aortic root calcification (ARC) rather than with aortic valve calcification (AVC), due to tissue similarity between the two types of vessel rather than with the valve leaflet tissue. Material and methodsWe studied 212 consecutive patients (age 72.5 ± 7.9 years, 91 females) with AS requiring aortic valve replacement (AVR) in two Heart Centers, who underwent multidetector cardiac CT preoperatively. CAC, AVC and ARC were quantified using Agatston scoring. Correlations were tested by Spearman's test and Mann–Whitney U-test was used for comparing different subgroups; bicuspid (BAV) vs tricuspid (TAV) aortic valve. ResultsCAC was present in 92%, AVC in 100% and ARC in 82% of patients. CAC correlated with ARC (rho = 0.51, p < 0.001) but not with AVC. The number of calcified coronary arteries correlated with ARC (rho = 0.45, p < 0.001) but not with AVC. 29/152 patients had echocardiographic evidence of BAV and 123 TAV, who were older (p < 0.001) but CAC was associated with TAV even after adjusting for age (p = 0.01). AVC score was associated with BAV after adjusting for age (p = 0.03) but ARC was not. Of the total cohort, 82 patients (39%) had significant coronary stenosis (>50%), but these were not different in the pattern of calcification from those without CAS. CAC was consistently higher in patients with risk factors for atherosclerosis compared to those without. ConclusionThe observed relationship between coronary and aortic root calcification suggests a diffuse arterial disease. The lack of relationship between coronary and aortic valve calcification suggests a different pathology.

Additive Prognostic Value of Coronary Artery Calcium Score Over Coronary Computed Tomographic Angiography Stenosis Assessment in Symptomatic Patients Without Known Coronary Artery Disease

The objective of this study was to examine the additive prognostic performance of coronary artery calcium score (CACS) over coronary computed tomography angiography (CCTA) stenosis assessment in symptomatic patients suspected for coronary artery disease (CAD) undergoing CCTA. A total of 805 symptomatic patients without known history of CAD who underwent coronary evaluation by multidetector cardiac CT were analyzed. Mean age of the cohort was 58 ± 13 years. A total of 44% (354 of 805) of the patients had a 0 CACS, 27% (215 of 805) had CACS 1 to 100, 14% (111 of 805) had CACS 101 to 400, and 15% (125 of 805) had CACS >400. CCTA showed normal coronary arteries in 43% (349 of 805) of patients, ≤50% stenosis in 42% (333 of 805), and >50% stenosis in 15% (123 of 805). Patients were followed for 2.3 ± 0.9 years. Major adverse cardiac event (MACE) was defined as cardiac death, nonfatal myocardial infarction, and late coronary revascularization. Overall incidence of MACE was 1.4% per year. Both CACS and CCTA stenosis were independently associated with increased MACE (p <0.05 for both). Addition of CACS into the model with clinical risk factors and CCTA stenosis significantly improved predictive performance for MACE from the model with clinical risk factors and CCTA stenosis only (global chi-square score 108 vs 70; p = 0.019). In conclusion; in symptomatic patients without known CAD, both CACS and CCTA stenosis were independently associated with increased cardiac events, and performing non-contrast-enhanced CACS evaluation in addition to contrast-enhanced CCTA improved predictive ability for future cardiac events compared to CCTA stenosis assessment alone.

Atherosclerosis Burden in Patients with Acute Chest Pain: Obesity Paradox

Obesity paradox has been described in various populations of coronary artery disease, mainly asymptomatic subjects. However, relationship between obesity and coronary artery calcification detected by cardiac CT in symptomatic patients has rarely been demonstrated. This study seeks to investigate whether the paradoxical relationship between obesity and coronary artery calcification exists in patients with acute chest pain. A final cohort of 1030 chest pain patients presenting at our emergency department who underwent coronary evaluation by multidetector cardiac CT were examined. With absent-to-mild coronary calcification (CAC score < 100) as a referent, multivariable analysis showed that presence of obesity (OR 0.564; 95% CI 0.395, 0.806; P 0.002), body mass index (OR 0.945; 95% CI 0.920, 0.971; P < 0.001), body weight (OR 0.987; 95% CI 0.979, 0.995; P 0.001), and body surface area (OR 0.582; 95% CI 0.369, 0.920; P 0.020) were inversely associated with moderate-to-severe coronary calcification (CAC score ≥ 100). This study extends the concept of obesity paradox to symptomatic patients undergoing coronary artery calcium score assessment. However, biological explanation(s) of this paradox remains unanswered.

Abstract 17265: The Relationship Between Subclinical Coronary Artery Atheroscelrosis and Brain Ischemic White Matter Disease in Healthy Individuals from High Risk Families

Background: Ischemic white matter disease (IWMD) is associated with incident stroke. Similarly subclinical coronary artery disease is associated with incident coronary artery disease (CAD) events. Although, atherogenesis in both vascular beds likely shares common mechanisms, the extent to which subclinical CAD is associated with preclinical IWMD in a young to middle-aged healthy asymptomatic high risk population with a family history of premature CAD remains unknown. Methods: We screened 405 apparently healthy participants in Genetic Study of Atherosclerotic Risk (GeneSTAR) (mean age 51.6 ± 10.6 years, 60% female, 36% African American) for CAD risk factors, and for the presence of calcified and noncalcified coronary plaque using dual-source 256 multi-detector cardiac CT angiography. The presence of IWMD was assessed by 3 Tesla brain MRI and the ischemic white-matter volume to brain volume (WVBV) ratio was calculated using direct measurements. A multivariate linear regression analysis predicting WVBV was performed for the presence of CAD, adjusting for age, sex, race, traditional CAD risk factors, and intrafamilial correlations using a generalized estimating equation (GEE). Results: Subclinical CAD was highly prevalent (43.0%). Individuals with coronary plaque had a higher ratio of WVBV (median 0.11, interquartile range [0.04 to 0.33]) as compared to those without coronary plaque (median 0.05 [0.01 to 0.14], p&lt;0.001). In the fully adjusted analysis, the presence of subclinical CAD was a significant predictor of WVBV (p=0.05), as was age (p&lt;0.001). Conclusion: This is the first study to show a strong association of subclinical CAD and occult ischemic white mater disease in healthy high-risk young to middle aged individuals, independent of traditional CAD risk factors, including age. The findings support the premise of shared causal pathways in the two vascular beds in families at increased risk for both CAD and stroke.

ACR Appropriateness Criteria® Chronic Chest Pain—High Probability of Coronary Artery Disease

Imaging is valuable in determining the presence, extent, and severity of myocardial ischemia and the severity of obstructive coronary lesions in patients with chronic chest pain in the setting of high probability of coronary artery disease. Imaging is critical for defining patients best suited for medical therapy or intervention, and findings can be used to predict long-term prognosis and the likely benefit from various therapeutic options. Chest radiography, radionuclide single photon-emission CT, radionuclide ventriculography, and conventional coronary angiography are the imaging modalities historically used in evaluating suspected chronic myocardial ischemia. Stress echocardiography, PET, cardiac MRI, and multidetector cardiac CT have all been more recently shown to be valuable in the evaluation of ischemic heart disease. Other imaging techniques may be helpful in those patients who do not present with signs classic for angina pectoris or in those patients who do not respond as expected to standard management. The ACR Appropriateness Criteria(®) are evidence-based guidelines for specific clinical conditions that are reviewed every 2 years by a multidisciplinary expert panel. The guideline development and review include an extensive analysis of current medical literature from peer-reviewed journals and the application of a well-established consensus methodology (modified Delphi) to rate the appropriateness of imaging and treatment procedures by the panel. In those instances in which evidence is lacking or not definitive, expert opinion may be used to recommend imaging or treatment.

Biphasic contrast medium injection in cardiac CT: moderate versus high concentration contrast material at identical iodine flux and iodine dose

ObjectiveTo prospectively investigate the influence of contrast material concentration on enhancement in cardiac CT by using a biphasic single-injection protocol.MethodsSixty-four-row multidetector cardiac CT angiography was performed in 159 patients randomised to a moderate or high contrast medium concentration. Contrast material injection included a first phase for enhancement of the coronary arteries and a second phase, at half the iodine flux, targeted at enhancement of the right ventricle. Contrast medium injection was followed by a saline flush. For both concentrations, injection duration (and thus total iodine dose) was adapted to the duration of the CT data acquisition and iodine flux was adjusted to patient weight. Attenuation was measured at various levels in the heart and vessels and the two concentrations compared, overall and per weight group.ResultsEnhancement of the aorta and left ventricle was significantly greater with the moderate than with the high concentration contrast medium. This remained true for the two higher weight groups. No difference was found in the lowest weight group or in the right ventricle and pulmonary outflow tract.ConclusionWith a biphasic injection protocol, enhancement of the aorta and left ventricle was weaker with the higher concentration of contrast material.

Pseudoaneurysm of the mitral-aortic intervalvular fibrosa following aortic valve replacement – diagnosis and dynamic evaluation with multidetector CT and transesophageal echocardiography

Sixteen-slice multidetector CT findings of a pulsatile pseudoaneurysm of the mitral-aortic intervalvular fibrosa, in a woman following aortic valve replacement, are presented. Multidetector CT depicted the pseudoaneurysm and enabled dynamic evaluation of its lumen through the cardiac cycle, documenting expansion during systole and almost complete collapse during diastole. This case illustrates the capabilities of multidetector cardiac CT in the evaluation of aortic valve pathology.

Multidetector CT of the coronary arteries and aortic root in a pediatric patient with homozygous familial hypercholesterolemia – correlation with invasive coronary angiography

Sixteen slice multidetector cardiac CT findings of a homozygous familial hypercholesterolemia pediatric patient are presented. Multidetector cardiac CT followed by invasive coronary angiography depicted a variety of diagnostic findings involving the aortic root and coronary arteries. This case illustrates the full capabilities of multidetector cardiac CT in monitoring aortic root and coronary artery disease in pediatric patients with homozygous familial hypercholesterolemia.