Prognostic Value of Coronary Computed Tomography Imaging in Patients at High Risk Without Symptoms of Coronary Artery Disease

Prognostic Value of Coronary Calcium Score in Asymptomatic Individuals: A Systematic Review

Despite updated guidelines and technological developments that allow for an accurate diagnosis, many asymptomatic individuals have a high risk of developing CAD or cardiac events. The CAC score can estimate a correct risk level for these subjects, which is clinically significant for adequate management of risk factors and obtaining personalized preventive therapy. This systematic review aims to assess the prognostic value of CAC score in asymptomatic individuals. According to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement, a systematic literature search was performed to identify original articles since 2010 that evaluated the prognostic value of CAC score in asymptomatic individuals. The quality of the included studies was assessed by the QUIPS tool. A total of 45 articles were selected. Many of these (25 studies) evaluated the prognostic value of CAC score in asymptomatic subjects. In comparison, others (20 studies) evaluated the association of CAC score with other clinical parameters and imaging modalities or the comparison with computed tomography coronary angiography (CTCA). Our findings showed that the CAC score provides valuable prognostic information for predicting CAD risk in asymptomatic individuals.

Validation of Coronary Artery Disease Reporting and Data System (CAD-RADS) and Application of Coronary Artery Calcium Data and Reporting System (CAC-DRS) as New Standardized Tools in the Management of Coronary Artery Disease Patients

Background and Objectives

The coronary artery disease reporting and data system (CAD-RADS) is intended to standardize the reporting of CCTA and the subsequent management guidelines of CAD. The present study was conducted to investigate the validation of CAD-RADS and the application of coronary calcium grading in CAD management.

Patients and Methods

The current study is a single-center prospective study that involved 177 participants with chest pain who were submitted to coronary CT angiography (CCTA). Two reviewers independently assessed CCTA results and gave each patient a CAD-RADS category. The reference standard for determining the clinical utility of CAD-RADS was invasive coronary angiography (ICA). The inter-reviewer agreement (IRA) was tested using the intra-class correlation (ICC).

Results

The study enrolled 111 cases with non-significant CAD and 66 cases with significant CAD based on ICA findings. According to the reviewer, the CAD-RADS had a sensitivity, specificity, and accuracy of 90.9 to 100%, 89.2 to 94.6%, and 93.16 to 93.2%, respectively, for predicting severe CAD. The IRA for CAD-RADS categories was excellent (ICC = 0.960). The best cut-off value for predicting severe CAD was CAD-RADS > 3. Significant relation between Ca and severe CAD (p<0.001) was detected.

Conclusion

The current study provides a good understanding of CAD-RADS as a standard tool with high diagnostic accuracy.

Use of Coronary Computed Tomography Angiography to Screen Hospital Employees with Cardiovascular Risk Factors

The objective of this study was to determine how coronary computed tomography angiography (CCTA) can be employed to detect coronary artery disease in hospital employees, enabling early treatment and minimizing damage. All employees of our hospital were assessed using the Framingham Risk Score. Those with a 10-year risk of myocardial infarction or death of >10% were offered CCTA; the Coronary Artery Disease Reporting and Data System (CAD-RADS) score was the outcome. A total of 3923 hospital employees were included, and the number who had received CCTA was 309. Among these 309, 31 (10.0%) had a CAD-RADS score of 3-5, with 10 of the 31 (32.3%) requiring further cardiac catheterization; 161 (52.1%) had a score of 1-2; and 117 (37.9%) had a score of 0. In the multivariate logistic regression, only age of ≥ 55 years (p < 0.05), hypertension (p < 0.05), and hyperlipidemia (p < 0.05) were discovered to be significant risk factors for a CAD-RADS score of 3-5. Thus, regular and adequate control of chronic diseases is critical for patients, and more studies are required to be confirmed if there are more significant risk factors.

ACR Appropriateness Criteria® Asymptomatic Patient at Risk for Coronary Artery Disease: 2021 Update

Coronary atherosclerotic disease is a leading cause of mortality and morbidity due to major cardiovascular events in the United States and abroad. Risk stratification and early preventive measures can reduce major cardiovascular events given the long latent asymptomatic period. Imaging tests can detect subclinical coronary atherosclerosis and aid initiation of targeted preventative efforts based on patient risk. A summary of available imaging tests for low-, intermediate-, and high-risk asymptomatic patients is outlined in this document. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.

Added value of cardiovascular calcifications for prediction of recurrent cardiovascular events and cardiovascular interventions in patients with established cardiovascular disease

The purpose is to investigate the added prognostic value of coronary artery calcium (CAC), thoracic aortic calcium (TAC), and heart valve calcium scores for prediction of a combined endpoint of recurrent major cardiovascular events and cardiovascular interventions (MACE +) in patients with established cardiovascular disease (CVD). In total, 567 patients with established CVD enrolled in a substudy of the UCC-SMART cohort, entailing cardiovascular CT imaging and calcium scoring, were studied. Five Cox proportional hazards models for prediction of 4-year risk of MACE + were developed; traditional CVD risk predictors only (model I), with addition of CAC (model II), TAC (model III), heart valve calcium (model IV), and all calcium scores (model V). Bootstrapping was performed to account for optimism. During a median follow-up of 3.43 years (IQR 2.28–4.74) 77 events occurred (MACE+). Calibration of predicted versus observed 4-year risk for model I without calcium scores was good, and the c-statistic was 0.65 (95%CI 0.59–0.72). Calibration for models II–V was similar to model I, and c-statistics were 0.67, 0.65, 0.65, and 0.68 for model II, III, IV, and V, respectively. NRIs showed improvement in risk classification by model II (NRI 15.24% (95%CI 0.59–29.39)) and model V (NRI 20.00% (95%CI 5.59–34.92)), but no improvement for models III and IV. In patients with established CVD, addition of the CAC score improved performance of a risk prediction model with classical risk factors for the prediction of the combined endpoint MACE+ . Addition of the TAC or heart valve score did not improve risk predictions.

Potential Application of Cardiac Computed Tomography for Early Detection of Coronary Atherosclerosis: From Calcium Score to Advanced Atherosclerosis Analysis

In the present article, an overview of advanced analysis of coronary atherosclerosis by coronary computed tomography angiography (CCTA) is provided, focusing on the potential application of this technique in a primary prevention setting. Coronary artery calcium score (CACS) has a well-demonstrated prognostic value even in a primary prevention setting; however, fibro-fatty, high-risk coronary plaque may be missed by this tool. On the contrary, even if not recommended for primary prevention in the general population, CCTA may enable early high-risk atherosclerosis detection, and specific subgroups of patients may benefit from its application. However, further studies are needed to determine the possible use of CCTA in a primary prevention setting.

Coronary Artery Disease Screening Using CT Coronary Angiography

BACKGROUND: The increased utility of CT coronary angiography (CTCA) in cardiovascular screenings of aircrew has led to the increased detection of asymptomatic coronary artery disease (CAD). A systematic review of studies relevant to the interpretation of CTCA for the occupational fitness assessment of high-risk vocations was performed, with findings used to describe the development of a pathway for the aeromedical disposition of military aviators with asymptomatic CAD.METHODS: Medline was searched using the terms CT coronary angiogram and screening and prognosis. The inclusion criteria were restricted to study populations ages > 18 yr, were asymptomatic, were not known to have CAD, had undergone CTCA, and with their associations with major adverse cardiovascular events (MACE) and other relevant cardiac outcomes reported.RESULTS: Included in this systematic review were 10 studies. When compared to subjects with no or nonobstructive CAD, those with obstructive CAD on CTCA had hazard ratios (HR) for cardiac events ranging from 1.42 to 105.48. Comparing subjects with nonobstructive CAD and those without CAD on CTCA, a lower HR of 1.19 for cardiac events was found. The annual event rates of subjects with no CAD on CTCA were extremely low, ranging from 0 to 0.5%.CONCLUSIONS: Based on the findings, we suggest that CTCA should only be performed in aircrew with higher cardiac risk profiles. Those found to have no CAD or minimal CAD (i.e., 25% stenosis) in a non-left main coronary artery on CTCA can be returned to flying duties. All other results should be further evaluated with an invasive angiogram.Cheong RWL, See B, Tan BBC, Koh CH. Coronary artery disease screening using CT coronary angiography. Aerosp Med Hum Perform. 2020; 91(10):812817.

Long-Term Prognostic Value of Coronary Computed Tomography Angiography in an Asymptomatic Elderly Population

Background

The prognostic value of coronary computed tomographic angiography (CCTA) for evaluating coronary artery disease in asymptomatic older adults is controversial. We investigated the prognostic value of CCTA in community‐dwelling elderly Koreans.

Methods and Results

Participants (n=470; mean age: 75.1±7.3 years) who underwent CCTA were enrolled from KLoSHA (Korean Longitudinal Study on Health and Aging), a community‐based prospective cohort. Using CCTA, coronary artery disease was classified as normal, nonobstructive, or obstructive according to the presence of 0%, <50%, or ≥50% stenosis, respectively. Coronary artery calcium scores were investigated together with Framingham risk score, atherosclerotic cardiovascular disease score, and individual risk factors. Major adverse cardiac events (MACE) were defined as a composite of cardiac event–related death or nonfatal myocardial infarction. During a median follow‐up of 8.2 years (interquartile range: 7.7–10.1 years), MACE occurred in 24 participants (5.1%). Compared with the normal group, participants in the obstructive group showed higher incidence of MACE (hazard ratio: 5.65; 95% CI, 1.22–26.16; P=0.027), whereas there were no significant differences in MACE between the normal and nonobstructive groups. The 8‐year event‐free survival rates were 98.1±1.1%, 94.9±1.6%, and 81.7±4.8% in the normal, nonobstructive, and obstructive groups, respectively. Compared with the Framingham risk score and coronary artery calcium score model, CCTA improved risk prediction by C‐index (from 0.698 to 0.749) and category‐free net reclassification index (0.478; P=0.022).

Conclusions

CCTA showed better long‐term prognostic value for MACE than coronary artery calcium score in this asymptomatic older population.

Incremental prognostic value of coronary computed tomography angiography over coronary calcium scoring for major adverse cardiac events in elderly asymptomatic individuals

Aims

Coronary computed tomography angiography (CCTA) and coronary artery calcium score (CACS) have prognostic value for coronary artery disease (CAD) events beyond traditional risk assessment. Age is a risk factor with very high weight and little is known regarding the incremental value of CCTA over CAC for predicting cardiac events in older adults.

Methods and results

Of 27 125 individuals undergoing CCTA, a total of 3145 asymptomatic adults were identified. This study sample was categorized according to tertiles of age (cut-off points: 52 and 62 years). CAD severity was classified as 0, 1–49, and ≥50% maximal stenosis in CCTA, and further categorized according to number of vessels ≥50% stenosis. The Framingham 10-year risk score (FRS) and CACS were employed as major covariates. Major adverse cardiovascular events (MACE) were defined as a composite of all-cause death or non-fatal MI. During a median follow-up of 26 months (interquartile range: 18–41 months), 59 (1.9%) MACE occurred. For patients in the top age tertile, CCTA improved discrimination beyond a model included FRS and CACS (C-statistic: 0.75 vs. 0.70, P-value = 0.015). Likewise, the addition of CCTA improved category-free net reclassification (cNRI) of MACE in patients within the highest age tertile (e.g. cNRI = 0.75; proportion of events/non-events reclassified were 50 and 25%, respectively; P-value <0.05, all). CCTA displayed no incremental benefit beyond FRS and CACS for prediction of MACE in the lower age tertiles.

Conclusion

CCTA provides added prognostic value beyond cardiac risk factors and CACS for the prediction of MACE in asymptomatic older adults.

Predictive value of coronary computed tomography angiography in asymptomatic individuals with diabetes mellitus: Systematic review and meta-analysis

BACKGROUND

Coronary CT angiography (CTA) is generally not established as a screening tool for asymptomatic individuals. However, it is controversial whether this test may have a role for screening asymptomatic individuals with diabetes mellitus (DM) due to the high prevalence of asymptomatic coronary artery disease (CAD) in this subgroup.

METHODS

We searched PubMed and EMBASE through May 2017 for studies that reported on the association between findings at coronary CTA and future cardiac events in asymptomatic individuals with DM. Summary hazard ratios for the presence of obstructive CAD (≥50% stenosis), presence of non-obstructive plaque (<50% stenosis), segment involvement score, and segment stenosis score were derived using a random effects regression model. I² was calculated to quantify between-study heterogeneity and causing factors were identified using meta-regression.

RESULTS

A total of 10 studies reporting on 5012 individuals with DM (median age: 62.3 years, median proportion of women: 40.5%) were included in the analysis. The presence of obstructive CAD on coronary CTA (vs. non-obstructive or no CAD) was associated with a significantly elevated risk for adverse events (summary HR: 4.07, 95% CI: 2.30 to 7.21). The estimated summary HR for non-obstructive plaque (vs. no CAD) was 2.17 (95% CI: 1.11 to 4.25). The pooled HRs per unit for segment stenosis score and segment involvement score were 1.44 (95% CI: 0.98 to 2.12), and 1.73 (95% CI: 1.07 to 2.80) respectively. On meta-regression analysis, we observed a trend towards a higher risk estimate in studies with a higher proportion of females (p = 0.1063).

CONCLUSION

The presence and extent of CAD on coronary CTA are strong, independent predictors of cardiovascular events in asymptomatic individuals with DM despite heterogeneity between studies in endpoints, study population and length of follow-up.

The proper use of coronary calcium score and coronary computed tomography angiography for screening asymptomatic patients with cardiovascular risk factors

Early detection and treatment of coronary artery disease (CAD) can reduce incidences of acute myocardial infarction. In this study, we determined the proper use of contributing risk factors and coronary artery calcium score (CACS) when screening asymptomatic patients with coronary arterial stenoses using coronary computed tomography angiography (CCTA). We reviewed 934 consecutive patients who received CACS and CCTA between December 2013 and November 2016. At least one cardiovascular disease risk factor was present in each of the 509 asymptomatic participants. Patients were grouped based on CACS into “zero,” “minimal” (0 < CACS ≤ 10), “mild” (10 < CACS ≤ 100), “moderate” (100 < CACS ≤ 400), and “excessive” (CACS > 400). Males over 45 years old with diabetes mellitus and hypertension had a higher risk of significant coronary stenosis. In multivariate analysis, age, sex, hypertension, and diabetes mellitus remained significant predictors of stenosis. A CACS of zero occurred in 227 patients (44.6%). There were no significant differences between the “zero” and “minimal” groups (p = 0.421), but the “mild,” “moderate,” and “excessive” groups showed correlations with significant coronary stenosis. Age, sex, diabetes mellitus, and hypertension were associated with higher risk of significant coronary stenosis. Asymptomatic patients with CACSs of zero do not require CCTA, and thereby avoid unnecessary radiation exposure.

Coronary atherosclerosis burden by coronary computed tomography in type II diabetes with preclinical non-obstructive carotid atherosclerosis and without inducible myocardial ischemia

AIMS

To quantify cardiovascular risk in persons with type-2 diabetes (DM) and established carotid atherosclerosis, without inducible myocardial ischemia by stress imaging.

METHODS

We selected clinically healthy DM and subjects without DM (nonDM, controls) with non-obstructive carotid atherosclerosis and without significant coronary artery disease (CAD) by stress echocardiography. Coronary flow velocity reserve (CFR) was assessed during stress echocardiography. In those with negative stress imaging, coronary artery calcium (CAC) assessment by computed tomography (CT) was proposed. Outcome at 180-day follow-up was performed by visits or telephone interview.

RESULTS

Total CAC was greater in DM (n=19) than in nonDM (n=19, CAC: 225±158 vs 78±65Agatston units, 156±161 vs 53±51 in the left anterior descendent artery, both p<0.05). Coronary stenosis burden was greater in DM than in nonDM, albeit <75% in all cases; CFR was lower in DM than nonDM (p<0.05). Mean age was slightly higher (69±6 vs 64±12, p>0.2), and male gender tended to be less frequent (63 vs 79%) with DM than with nonDM; all subjects showed dyslipidemia, and almost all had arterial hypertension. Based on CAC, a 10-year cardiovascular risk was 10-20% in 78% of the DM and in 28% of the non-DM, and was >20% in 11% of the DM but in none of the nonDM. A single non-fatal myocardial infarction was recorded within 180days from test, among DM.

CONCLUSIONS

Based on CAC, in the presence of non-obstructive carotid atherosclerosis, asymptomatic DM may show significantly higher CAD burden than nonDM even in the absence of inducible myocardial ischemia.