Diagnosing Heart Disease with Cardiac Computed Tomography (original) (raw)
International Journal of Cardiovascular Imaging
The correlation between formal coronary artery calcium scoring (CACS) determined by multi-detector CT (MDCT) and the presence of coronary calcium on standard non-gated CT chest examinations was evaluated. In 163 consecutive healthy participants, we performed screening same-day standard non-gated, non-enhanced CT chest exams followed by high-resolution, ECG-synchronized MDCT exams for CACS. For the standard CT examinations, a scoring system (Weston score, range 0–12) was developed assigning a score (0–3) for each coronary vessel including the left main trunk. Overall, 30% and 39% of patients had CAC on standard CT and MDCT exams, respectively (P = 0.13). CAC on standard CT was highly correlated to the Agatston CACS on the MDCT (Spearman correlation coefficient 0.83, P < 0.001). Absence of calcium on the standard CT exam was associated with a very low CACS (mean Agatston 0.5, range 0–19). A Weston score >2 identified a CACS > 100 with an area under the curve of 0.976, sensitivity of 100%, and specificity of 85%. A Weston score >7 identified a CACS > 400 with an area under the curve of 0.991, sensitivity of 100%, specificity of 98%. The intra-observer variability was low as was the inter-observer variability between a cardiac specialized radiologist and a non-specialized reader. A visual coronary artery scoring system on standard, non-gated CT correlates well with traditional methods for CACS. Further, a non-expert cardiac radiologist performed equally well to a cardiac expert. This information suggests that a visual scoring system, at least in a descriptive manner can be utilized for a general statement about coronary artery calcification seen on standard CT imaging to guide clinicians in risk stratification.
Journal of Cardiovascular and Thoracic Research
Introduction Cardiovascular diseases, including coronary artery disease (CAD), are among the most common causes of death in the elderly population. According to the World Health Organization (WHO), cardiovascular diseases take nearly 18 million lives annually. 1 The lifetime risk of developing CAD is estimated to be 49 percent in men and 32 percent in women. 2 Therefore, identifying people at risk and early diagnosis is important. Older age, male gender, hypertension, diabetes, dyslipidemia, obesity, smoking, and low physical activity are among the most established risk factors for cardiovascular diseases. 3,4 Recent studies have found that coronary artery calcium (CAC) is a strong independent predictor of CAD. 5-8 Calcification of the coronary arteries has an important role in the pathophysiology of atherosclerosis. CAC can be easily measured by noninvasive imaging methods, including electron-beam tomography (EBT) or multidetector computed tomography (CT). 9 CAC score (CACS) measured by noncontrast cardiac CT scan is a low-radiation and relatively cheap test that provide a quantitative assessment of the overall coronary atherosclerotic burden. 10 Growing evidence suggests that CACS is a useful test for risk stratification of both symptomatic and asymptomatic individuals. 11-13 Higher CACSs has been shown to be associated with a higher risk of major cardiovascular events and all-cause mortality. 5,14,15 Several studies have claimed that there are some associations between CACS and cardiac risk factors. 16-18 However, there were great inconsistencies between the reported results. Here we aimed to investigate the association between CACS and demographic, clinical, laboratory, and CT angiographic findings in patients with suspected CAD. We also evaluated the predictive value of
International Journal of Cardiovascular Imaging, 2009
Present guidelines discourage the use of CT coronary angiography (CTCA) in symptomatic angina patients. We examined the relation between coronary calcium score (CS) and the performance of CTCA in patients with stable and unstable angina in order to understand under which conditions CTCA might be a gate-keeper to conventional coronary angiography (CCA) in such patients. We included 360 patients between 50 and 70 years old with stable and unstable angina who were clinically referred for CCA irrespective of CS. Patients received CS and CCTA on 64-slice scanners in a multicenter cross-sectional trial. The institutional review board approved the study. Diagnostic performance of CTCA to detect or rule out significant coronary artery disease was calculated on a per patient level in pre-defined CS categories. The prevalence of significant coronary artery disease strongly increased with CS. Negative CTCA were associated with a negative likelihood ratio of <0.1 independent of CS. Positive CTCA was associated with a high positive likelihood ratio of 9.4 if CS was <10. However, for higher CS the positive likelihood ratio never exceeded 3.0 and for CS >400 it decreased to 1.3. In the 62 (17%) patients with CS <10, CTCA reliably identified the 42 (68%) of these patients without significant CAD, at no false negative CTCA scans. In symptomatic angina patients, a negative CTCA reliably excludes significant CAD but the additional value of CTCA decreases sharply with CS >10 and especially with CS >400. In patients with CS <10, CTCA provides excellent diagnostic performance.
Plos One, 2014
Aims: To investigate the value of coronary calcium scoring (CCS) as a filter scan prior to coronary computed tomography angiography (CCTA). Methods and Results: Between February 2008 and April 2011, 732 consecutive patients underwent clinically indicated CCTA. During this 'control phase', CCS was performed in all patients. In patients with CCS$800, CCTA was not performed. During a subsequent 'CCTA phase' (May 2011-May 2012) another 200 consecutive patients underwent CCTA, and CCS was performed only in patients with increased probability for severe calcification according to age, gender and atherogenic risk factors. In patients where CCS was not performed, calcium scoring was performed in contrast-enhanced CCTA images. Significant associations were noted between CCS and age (r = 0.30, p,0.001) and coronary risk factors (x 2 = 37.9; HR = 2.2; 95%CI = 1.7-2.9, p,0.001). Based on these associations, a #3% pre-test probability for CCS$800 was observed for males ,61 yrs. and females ,79 yrs. According to these criteria, CCS was not performed in 106 of 200 (53%) patients during the 'CCTA phase', including 47 (42%) males and 59 (67%) females. This resulted in absolute radiation saving of ,1 mSv in 75% of patients younger than 60 yrs. Of 106 patients where CCS was not performed, estimated calcium scoring was indeed ,800 in 101 (95%) cases. Non-diagnostic image quality due to calcification was similar between the 'control phase' and the 'CCTA' group (0.25% versus 0.40%, p = NS). Conclusion: The value of CCS as a filter for identification of a high calcium score is limited in younger patients with intermediate risk profile. Omitting CCS in such patients can contribute to further dose reduction with cardiac CT studies.
European Heart Journal, 2016
To compare the effectiveness and safety of a cardiac computed tomography (CT) algorithm with functional testing in patients with symptoms suggestive of coronary artery disease (CAD). Methods and results Between April 2011 and July 2013, 350 patients with stable angina, referred to the outpatient clinic of four Dutch hospitals, were prospectively randomized between cardiac CT and functional testing (2 : 1 ratio). The tiered cardiac CT protocol included a calcium scan followed by CT angiography if the Agatston calcium score was between 1 and 400. Patients with test-specific contraindications were not excluded from study participation. By 1 year, fewer patients randomized to cardiac CT reported anginal complaints (P ¼ 0.012). The cumulative radiation dose was slightly higher in the CT group (6.6 + 8.7 vs. 6.1 + 9.3 mSv; P , 0.0001). After 1.2 years, event-free survival was 96.7% for patients randomized to CT and 89.8% for patients randomized to functional testing (P ¼ 0.011). After CT, the final diagnosis was established sooner (P , 0.0001), and additional downstream testing was required less frequently (25 vs. 53%, P , 0.0001), resulting in lower cumulative diagnostic costs (E369 vs. E440; P , 0.0001). Conclusion For patients with suspected stable CAD, a tiered cardiac CT protocol offers an effective and safe alternative to functional testing. Incorporating the calcium scan into the diagnostic workup was safe and lowered diagnostic expenses and radiation exposure.
Proceedings of Singapore Healthcare, 2011
Screening for coronary artery disease (CAD), using CT coronary angiography, coronary artery calcium scoring and myocardial perfusion imaging, seems an attractive idea. However, there is considerable uncertainty whether the overall potential benefits outweigh the risks. In a situation where the prevalence of disease is very low, the positive predictive value of any test will tend to be low, and false positive results frequent, requiring a large number of individuals to undergo further testing to confirm disease in a small number of patients. Even when disease is detected, the benefits of revascularisation are uncertain in asymptomatic populations. There is considerable uncertainty about the risks from radiation as a result of imaging tests such as CT scans. Based on available data, the actual risks of malignancy for most individuals appear to be small and of limited concern in a symptomatic patient with a moderate likelihood of disease. However, in a low risk population as in the con...
2006
Background/Objective: The most important lesions in coronary artery disease (CAD) are coronary artery plaques, many of which are calcified. Multi-slice spiral CT (MSCT) scanners can concurrently perform coronary calcium scoring (Ca-Score) as a predictor of CAD and coronary CT-angiography (CCTA) as the determining factor in therapeutic decision-making. We aimed to determine the agreement of a Ca-Score more than 100 (based on Agatston technique) with coronary artery stenosis significance on CCTA. Patients and Methods: Using ECG-gated MSCT, 65 patients who were referred for CCTA were assessed both for their Ca-Score and a significant (≥50% diameter reduction) coronary stenosis, simultaneously. Their total Ca-Score were classified in three groups (a-0, bless than 100, and c-≥ 100). The severity of coronary stenosis was categorized to further three groups (1lack of stenotic lesion, 2-presence of non-significant stenosis, and 3-presence of significant stenosis). Results: Of 65 patients referred for CCTA, 42 (64.61%) had no CAD, 8 (12.3%) had nonsignificant lesions, and 15 (23.09%) had significant stenoses. Forty-three (66.2%) out of 65 subjects had a zero, 14 (21.5%) had scores <100, and 8 (12.3%) had ≥ 100 Ca-Score. In the first group (Ca-score = 0), only one had significant stenosis; while 50% of the patients in the second group (Ca-score < 100) and 87.5% from the third group (Ca-score of ≥ 100) had significant stenosis. Significant coronary stenosis has a moderate-to-good agreement with a Ca-Score of 100 or higher, compared to those with a Ca-Score of less than 100, and this was statistically significant (P < 0.0001). Conclusion: In patients with a calcium score of 100 or more, performing CCTA may be advisable to assess the likelihood of significant CAD.
Can Non-calcified Coronary Artery Plaques Be Detected on Non-contrast CT Calcium Scoring Studies?
Academic Radiology, 2011
Rationale and Objectives: Coronary computed tomographic (CT) angiography has been shown to detect noncalcified coronary artery plaque. Depending on tissue composition, noncalcified plaque differs in CT attenuation from blood and epicardial fat. The aim of this study was to determine whether noncalcified plaque can be visually detected on non-contrast-enhanced CT calcium scoring studies.
2017
BACKGROUND-Coronary artery disease is a major cause of morbidity and mortality. CT Coronary angiography is a useful tool in evaluation of patients with suspected coronary artery disease with excellent temporal as well as spatial resolution. AIMS & OBJECTIVES-1. Quantification of coronary calcium by MDCT and it's implication for determining risk of cardiovascular events. 2. Detection of significant coronary stenosis (>50percent narrowing of it's lumen). MATERIAL AND METHODS-is study was hospital based prospective study and was performed on 30 patients with clinical features suggestive of coronary artery disease. CT Coronary angiography was performed on 64-MDCT scanner Ingenuity (Philips Medical Systems). 80 ml of non ionic contrast iohexol with concentration of 300 mg iodine/ml was given followed by 50 ml saline flush at injection rate of 5.5ml/sec into antecubital vein. RESULTS-Out of 30 patients, 21were males and 9 were females. Sixteen patients had calcium score of 0, eight patients had a calcium score 11-100, five patients had calcium score 101-400 and one patient had calcium score of 400-800. irty patients had 48 lesions, RCA had 4 obstructive and 5 non-obstructive lesions, LAD had 14 obstructive and 13 non-obstructive lesions and LCx had 6 obstructive and 4 non-obstructive lesions. e CTCA had diagnostic sensitivity of 100%, positive predictive value 80% and negative predictive value was 100%. Out of 48 plaques 10 were calcified plaques, 22 non calcified plaques and 16 mixed plaques. CONCLUSION-Contrast-enhanced 64-slice CT is a clinically robust modality that allows non-invasive visualization of coronary arteries and identification of coronary lesions with excellent accuracy. Its high diagnostic accuracy made it an excellent non-invasive diagnostic tool in work up of patients with suspected CAD.
The American Journal of Cardiology, 2010
The purpose of the present study was to assess the impact of clinical presentation and pretest likelihood on the relation between coronary calcium score (CCS) and computed tomographic coronary angiography (CTA) to determine the role of CCS as a gatekeeper to CTA in patients presenting with chest pain. In 576 patients with suspected coronary artery disease (CAD), CCS and CTA were performed. CCS was categorized as 0, 1 to 400, and >400. On CT angiogram the presence of significant CAD (>50% luminal narrowing) was determined. Significant CAD was observed in 14 of 242 patients (5.8%) with CCS 0, in 94 of 260 patients (36.2%) with CCS 1 to 400, and in 60 of 74 patients (81.1%) with CCS >400. In patients with CCS 0, prevalence of significant CAD increased from 3.9% to 4.1% and 14.3% in nonanginal, atypical, and typical chest pain, respectively, and from 3.4% to 3.9% and 27.3% with a low, intermediate, and high pretest likelihood, respectively. In patients with CCS 1 to 400, prevalence of significant CAD increased from 27.4% to 34.7% and 51.7% in nonanginal, atypical, and typical chest pain, respectively, and from 15.4% to 35.6% and 50% in low, intermediate, and high pretest likelihood, respectively. In patients with CCS >400, prevalence of significant CAD on CT angiogram remained high (>72%) regardless of clinical presentation and pretest likelihood. In conclusion, the relation between CCS and CTA is influenced by clinical presentation and pretest likelihood. These factors should be taken into account when using CCS as a gatekeeper for CTA.
European Radiology, 2009
To evaluate the diagnostic accuracy of 64-slice CT coronary angiography (CT-CA) for the detection of significant coronary artery stenosis in patients with zero on the Agatston Calcium Score (CACS). We enrolled 279 consecutive patients (96 male, mean age 48±12 years) with suspected coronary artery disease. Patients were symptomatic (n=208) or asymptomatic (n=71), and underwent conventional coronary angiography (CAG). For CT-CA we administered an IV bolus of 100 ml of iodinated contrast material. CT-CA was compared to CAG using a threshold for significant stenosis of ≥50%. The prevalence of disease demonstrated at CAG was 15% (1.4% in asymptomatic). The population at CAG showed no or non-significant disease in 85% (238/279), single vessel disease in 9% (25/279), and multi-vessel disease in 6% (16/279). Sensitivity, specificity, and positive and negative predictive values of CT-CA vs. CAG on the patient level were 100%, 95%, 76%, and 100% in the overall population and 100%, 100%, 100%, and 100% in asymptomatic patients, respectively. CT-CA proves high diagnostic performance in patients with or without symptoms and with zero CACS. The prevalence of significant disease detected by CT-CA was not negligible in asymptomatic patients. The role of CT-CA in asymptomatic patients remains uncertain.
Iranian Red Crescent Medical Journal, 2014
Background: Coronary artery calcification which is determined quantitatively by coronary calcium scoring has been known as a sign of coronary stenosis and thus future cardiac events; hence it has been noticed on spotlight of researchers in recent years. Developing different method for early and optimal detection of coronary artery disease (CAD) is really essential as CAD are the first cause of death in population. Objectives: To evaluate predictive value of vessel specific coronary artery calcium (CAC) score in predicting obstructive coronary artery disease.
Can nontriggered thoracic CT be used for coronary artery calcium scoring? A phantom study
Medical Physics, 2013
Purpose: Coronary artery calcium score, traditionally based on electrocardiography (ECG)-triggered computed tomography (CT), predicts cardiovascular risk. However, nontriggered CT is extensively utilized. The study-purpose is to evaluate the in vitro agreement in coronary calcium score between nontriggered thoracic CT and ECG-triggered cardiac CT. Methods: Three artificial coronary arteries containing calcifications of different densities (high, medium, and low), and sizes (large, medium, and small), were studied in a moving cardiac phantom. Two 64-detector CT systems were used. The phantom moved at 0-90 mm/s in nontriggered low-dose CT as index test, and at 0-30 mm/s in ECG-triggered CT as reference. Differences in calcium scores between nontriggered and ECG-triggered CT were analyzed by t-test and 95% confidence interval. The sensitivity to detect calcification was calculated as the percentage of positive calcium scores. Results: Overall, calcium scores in nontriggered CT were not significantly different to those in ECGtriggered CT (p > 0.05). Calcium scores in nontriggered CT were within the 95% confidence interval of calcium scores in ECG-triggered CT, except predominantly at higher velocities (≥50 mm/s) for the high-density and large-size calcifications. The sensitivity for a nonzero calcium score was 100% for large calcifications, but 46% ± 11% for small calcifications in nontriggered CT. Conclusions: When performing multiple measurements, good agreement in positive calcium scores is found between nontriggered thoracic and ECG-triggered cardiac CT. Agreement decreases with increasing coronary velocity. From this phantom study, it can be concluded that a high calcium score can be detected by nontriggered CT, and thus, that nontriggered CT likely can identify individuals at high risk of cardiovascular disease. On the other hand, a zero calcium score in nontriggered CT does not reliably exclude coronary calcification.
Clinical Evaluation and Calcium Score as Methods for Selecting Patients Eligible for CT Angiogram
2014
PURPOSE:Our aim was to compare the prognostic performance of computed tomography coronary angiography (CTA) and exercise electrocardiography (ex-ECG) in patients with suspected coronary artery disease (CAD). METHODS: We enrolled 60 patients (age 61.3 ± 10.4 years, 40 men) with angina and no history of CAD. All underwent ex-ECG and CTA and were followed for 12 months. The endpoints were cardiac events - nonfatal myocardial infarction, cardiac death, and revascularization. RESULTS: ex-ECG and CTA were positive in 36 (60%) and 24 (40%) of 60 patients, respectively. Both ex-ECG and CTA were predictors of cardiac events (hazard ratio [HR]: 2, p < 0.0001 and HR: 20, 95% p < 0.0001, respectively) and hard cardiac events (HR: 1.9, 95% ,p = 0.02 and HR: 6.8; p < 0.0001, respectively), in a multivariate analysis, CAD with ≥50% stenoses detected by CTA was the only independent predictor of hard cardiac events. Ex-ECG provides a further risk stratification in the subset of patients wit...