Coronary artery calcification is common on nongated chest computed tomography imaging

Reporting of coronary artery calcification on chest CT studies in patients with interstitial lung disease

AIM

To evaluate the prevalence of coronary artery calcification (CAC) on non-contrast computed tomography (CT) of the thorax in patients with interstitial lung disease (ILD), assess consistency of CAC reporting and assess incidence of subsequent cardiac events.

MATERIALS AND METHODS

Patients with known interstitial lung disease who underwent a CT thorax over a 2-year period were retrospectively reviewed. Presence of CAC was assessed using a visual scale for CAC reporting and graded as mild, moderate, or severe by two cardiothoracic radiologists. CT reports were reviewed to determine if presence of CAC had been described. Electronic medical records were reviewed for any subsequent cardiothoracic events from the date of the CT thorax to present.

RESULTS

254 patients were included in the analysis (54.7% men; mean age 59.9 yo). 43.7% had CAC on their CT thorax; however, in 87.3% of those, reports did not comment on its presence. 8 patients had cardiac events; 7 of them had CAC on CT although only in 1 case this was reported. Global CAC and LAD CAC Patients with cardiac events had a significantly higher global CAC (p=0.016) and LAD CAC (p=0.048) when compared to patients without.

CONCLUSION

We demonstrated a high prevalence of CAC in ILD patients and its significant association with adverse cardiac events. Unfortunately, CAC on CT thorax is still largely unreported. As per recent BSCI/BSCCT and BSTI guidelines, reporting of CAC should become part of routine practice, as may prompt prevention and impact on patients outcome.

Prevalence and clinical implications of coronary artery calcium scoring on non-gated thoracic computed tomography: a systematic review and meta-analysis

OBJECTIVES

Coronary artery calcifications (CACs) indicate the presence of coronary artery disease. CAC can be found on thoracic computed tomography (CT) conducted for non-cardiac reasons. This systematic review and meta-analysis of non-gated thoracic CT aims to assess the clinical impact and prevalence of CAC.

METHODS

Online databases were searched for articles assessing prevalence, demographic characteristics, accuracy and prognosis of incidental CAC on non-gated thoracic CT. Meta-analysis was performed using a random effects model.

RESULTS

A total of 108 studies (113,406 patients) were included (38% female). Prevalence of CAC ranged from 2.7 to 100% (pooled prevalence 52%, 95% confidence interval [CI] 46-58%). Patients with CAC were older (pooled standardised mean difference 0.88, 95% CI 0.65-1.11, p < 0.001), and more likely to be male (pooled odds ratio [OR] 1.95, 95% CI 1.55-2.45, p < 0.001), with diabetes (pooled OR 2.63, 95% CI 1.95-3.54, p < 0.001), hypercholesterolaemia (pooled OR 2.28, 95% CI 1.33-3.93, p < 0.01) and hypertension (pooled OR 3.89, 95% CI 2.26-6.70, p < 0.001), but not higher body mass index or smoking. Non-gated CT assessment of CAC had excellent agreement with electrocardiogram-gated CT (pooled correlation coefficient 0.96, 95% CI 0.92-0.98, p < 0.001). In 51,582 patients, followed-up for 51.6 ± 27.4 months, patients with CAC had increased all cause mortality (pooled relative risk [RR] 2.13, 95% CI 1.57-2.90, p = 0.004) and major adverse cardiovascular events (pooled RR 2.91, 95% CI 2.26-3.93, p < 0.001). When CAC was present on CT, it was reported in between 18.6% and 93% of reports.

CONCLUSION

CAC is a common, but underreported, finding on non-gated CT with important prognostic implications.

CLINICAL RELEVANCE STATEMENT

Coronary artery calcium is an important prognostic indicator of cardiovascular disease. It can be assessed on non-gated thoracic CT and is a commonly underreported finding. This represents a significant population where there is a potential missed opportunity for lifestyle modification recommendations and preventative therapies. This study aims to highlight the importance of reporting incidental coronary artery calcium on non-gated thoracic CT.

KEY POINTS

• Coronary artery calcification is a common finding on non-gated thoracic CT and can be reliably identified compared to gated-CT. • Coronary artery calcification on thoracic CT is associated with an increased risk of all cause mortality and major adverse cardiovascsular events. • Coronary artery calcification is frequently not reported on non-gated thoracic CT.

Coronary Artery Calcium Identified on Non-Gated Chest CT Scans: A Wasted Opportunity for Preventive Cardiological Care

BACKGROUND

Coronary artery calcium (CAC) evaluated on dedicated cardiac computed tomography (CT) is an independent predictor of cardiovascular events. This study aimed to evaluate the correlation between CAC detected on non-gated standard chest CT and coronary lesions on coronary angiography (CAG) and determine its impact on prognosis.

METHODS

Consecutive patients who underwent CAG due to acute coronary syndrome and had prior non-contrasted non-gated chest CT were included and retrospectively evaluated. Coronary artery calcium was evaluated by quantitative (Agatston score) and qualitative (visual assessment) assessment.

RESULTS

A total of 114 patients were included in this study. The mean time difference between chest CT and CAG was 23 months. Coronary artery calcium was visually classified as mild, moderate, and severe in 31%, 33%, and 16% of patients, respectively. Moderate or severe CAC was an independent predictor of significant lesions on CAG (OR 22; 95% CI 8-61; p<0.001) and all-cause mortality (OR 4; 95% CI 2-9; p=0.001). Quantitative CAC evaluation accurately predicted significant lesions on CAG (AUC 0.81; p<0.001). While significant CAC was identified in 80% of chest CTs, formal reporting was 25%.

CONCLUSION

Coronary artery calcium evaluation with chest CT was feasible and strongly associated with severity of coronary disease on CAG and mortality. Although the identification of CAC on chest CT represents a unique opportunity for cardiovascular risk stratification for preventive care, CAC underreporting is frequent.

Assessing cardiovascular risk with mammography and non-contrast chest CT: A review of the literature and clinical implications

Coronary artery disease (CAD) is the leading cause of mortality and disability globally. In the United States, about 7.2% of adults aged 20 and older are affected by CAD. However, due to its progression over decades, CAD is often undetected and unnoticed until plaque ruptures. This leads to partial or complete artery blockage, resulting in myocardial infarction. Thus, new screening methods for early detection of CAD are needed to prevent and minimize the morbidity and mortality from CAD. Vascular calcifications seen on mammography and non-contrast chest CT (NCCT) can be used for the early detection of CAD and are an accurate predictor of cardiovascular risk. This paper aims to review the basic epidemiology, pathophysiology, imaging findings, and correlation of long-term cardiovascular outcomes with vascular calcifications on mammography and NCCT.

Existing Nongated CT Coronary Calcium Predicts Operative Risk in Patients Undergoing Noncardiac Surgeries (ENCORES)

BACKGROUND

Preoperative cardiovascular risk stratification before noncardiac surgery is a common clinical challenge. Coronary artery calcium scores from ECG-gated chest computed tomography (CT) imaging are associated with perioperative events. At the time of preoperative evaluation, many patients will not have had ECG-gated CT imaging, but will have had nongated chest CT studies performed for a variety of noncardiac indications. We evaluated relationships between coronary calcium severity estimated from previous nongated chest CT imaging and perioperative major clinical events (MCE) after noncardiac surgery.

METHODS

We retrospectively identified consecutive adults age ≥45 years who underwent in-hospital, major noncardiac surgery from 2016 to 2020 at a large academic health system composed of 4 acute care centers. All patients had nongated (contrast or noncontrast) chest CT imaging performed within 1 year before surgery. Coronary calcium in each vessel was retrospectively graded from absent to severe using a 0 to 3 scale (absent, mild, moderate, severe) by physicians blinded to clinical data. The estimated coronary calcium burden (ECCB) was computed as the sum of scores for each coronary artery (0 to 9 scale). A Revised Cardiac Risk Index was calculated for each patient. Perioperative MCE was defined as all-cause death or myocardial infarction within 30 days of surgery.

RESULTS

A total of 2554 patients (median age, 68 years; 49.7% women; median Revised Cardiac Risk Index, 1) were included. The median time interval from nongated chest CT imaging to noncardiac surgery was 15 days (interquartile range, 3-106 days). The median ECCB was 1 (interquartile range, 0-3). Perioperative MCE occurred in 136 (5.2%) patients. Higher ECCB values were associated with stepwise increases in perioperative MCE (0: 2.9%, 1-2: 3.7%, 3-5: 8.0%; 6-9: 12.6%, P<0.001). Addition of ECCB to a model with the Revised Cardiac Risk Index improved the C-statistic for MCE (from 0.675 to 0.712, P=0.018), with a net reclassification improvement of 0.428 (95% CI, 0.254-0.601, P<0.0001). An ECCB ≥3 was associated with 2-fold higher adjusted odds of MCE versus an ECCB <3 (adjusted odds ratio, 2.11 [95% CI, 1.42-3.12]).

CONCLUSIONS

Prevalence and severity of coronary calcium obtained from existing nongated chest CT imaging improve preoperative clinical risk stratification before noncardiac surgery.

An Opportunity to Seize From Low Hanging Fruits: Capitalising on Incidentally Reported Coronary Artery Calcification

AIM

We investigated the prevalence of incidental coronary artery calcifications (CAC) from non-electrocardiogram (ECG)-gated computed tomography (CT) chest (both contrast and non-contrast) for inpatients. We also assessed for downstream investigation and statin prescription from the inpatient teams. Incidental CAC are frequent findings on non-ECG-gated CT chest. It is associated with adverse prognosis in multiple patient cohorts.

METHOD

All non-ECG-gated CT chest done as inpatients from a single centre referred from 1 January 2022 to 31 December 2022 with reported incidental CAC were reviewed for inclusion. Patients who had a history of known coronary artery disease, history of coronary stent or bypass, and presence of cardiac devices were excluded.

RESULTS

Total of 123 patients were included, making the prevalence 6.2% (123/1,980). The median age is 76 years (interquartile range 69-85) and predominantly male at 54.5%. The majority of CT chest done were contrasted scans (91.1%). Only 26.8% of CAC were reported on severity with visual quantification, with 7.3% each reported for both moderate and severe CAC. Only 2.4% of CAC were reported in the conclusion of the CT report. Most of these patients were asymptomatic (34.1%). A total of 20.3% of patients had further tests done. Inpatient hospital mortality was 8.1%. About 23.6% and 34.1% of patients were on aspirin and statin therapy respectively at baseline. There was only 1 patient (1.2%) who was prescribed with new statin therapy on discharge.

CONCLUSION

Incidental CAC is prevalent in inpatient settings and remains under-recognised by ordering clinicians, with low prescription rate of statin therapy. Practice-changing measures to standardise reporting of incidental CAC is needed to identify patients with subclinical coronary disease and initiate preventive interventions.

Association of Coronary Artery Calcium Detected by Routine Ungated CT Imaging With Cardiovascular Outcomes

BACKGROUND

Coronary artery calcium (CAC) is a strong predictor of cardiovascular events across all racial and ethnic groups. CAC can be quantified on nonelectrocardiography (ECG)-gated computed tomography (CT) performed for other reasons, allowing for opportunistic screening for subclinical atherosclerosis.

OBJECTIVES

The authors investigated whether incidental CAC quantified on routine non-ECG-gated CTs using a deep-learning (DL) algorithm provided cardiovascular risk stratification beyond traditional risk prediction methods.

METHODS

Incidental CAC was quantified using a DL algorithm (DL-CAC) on non-ECG-gated chest CTs performed for routine care in all settings at a large academic medical center from 2014 to 2019. We measured the association between DL-CAC (0, 1-99, or ≥100) with all-cause death (primary outcome), and the secondary composite outcomes of death/myocardial infarction (MI)/stroke and death/MI/stroke/revascularization using Cox regression. We adjusted for age, sex, race, ethnicity, comorbidities, systolic blood pressure, lipid levels, smoking status, and antihypertensive use. Ten-year atherosclerotic cardiovascular disease risk was calculated using the pooled cohort equations.

RESULTS

Of 5,678 adults without ASCVD (51% women, 18% Asian, 13% Hispanic/Latinx), 52% had DL-CAC >0. Those with DL-CAC ≥100 had an average 10-year ASCVD risk of 24%; yet, only 26% were on statins. After adjustment, patients with DL-CAC ≥100 had increased risk of death (HR: 1.51; 95% CI: 1.28-1.79), death/MI/stroke (HR: 1.57; 95% CI: 1.33-1.84), and death/MI/stroke/revascularization (HR: 1.69; 95% CI: 1.45-1.98) compared with DL-CAC = 0.

CONCLUSIONS

Incidental CAC ≥100 was associated with an increased risk of all-cause death and adverse cardiovascular outcomes, beyond traditional risk factors. DL-CAC from routine non-ECG-gated CTs identifies patients at increased cardiovascular risk and holds promise as a tool for opportunistic screening to facilitate earlier intervention.

Incidental Coronary Artery Calcium: Opportunistic Screening of Previous Nongated Chest Computed Tomography Scans to Improve Statin Rates (NOTIFY-1 Project)

BACKGROUND

Coronary artery calcium (CAC) can be identified on nongated chest computed tomography (CT) scans, but this finding is not consistently incorporated into care. A deep learning algorithm enables opportunistic CAC screening of nongated chest CT scans. Our objective was to evaluate the effect of notifying clinicians and patients of incidental CAC on statin initiation.

METHODS

NOTIFY-1 (Incidental Coronary Calcification Quality Improvement Project) was a randomized quality improvement project in the Stanford Health Care System. Patients without known atherosclerotic cardiovascular disease or a previous statin prescription were screened for CAC on a previous nongated chest CT scan from 2014 to 2019 using a validated deep learning algorithm with radiologist confirmation. Patients with incidental CAC were randomly assigned to notification of the primary care clinician and patient versus usual care. Notification included a patient-specific image of CAC and guideline recommendations regarding statin use. The primary outcome was statin prescription within 6 months.

RESULTS

Among 2113 patients who met initial clinical inclusion criteria, CAC was identified by the algorithm in 424 patients. After chart review and additional exclusions were made, a radiologist confirmed CAC among 173 of 194 patients (89.2%) who were randomly assigned to notification or usual care. At 6 months, the statin prescription rate was 51.2% (44/86) in the notification arm versus 6.9% (6/87) with usual care (P<0.001). There was also more coronary artery disease testing in the notification arm (15.1% [13/86] versus 2.3% [2/87]; P=0.008).

CONCLUSIONS

Opportunistic CAC screening of previous nongated chest CT scans followed by clinician and patient notification led to a significant increase in statin prescriptions. Further research is needed to determine whether this approach can reduce atherosclerotic cardiovascular disease events.

REGISTRATION

URL: https://www.

CLINICALTRIALS

gov; Unique identifier: NCT04789278.

What should we do about Coronary Calcification on Thoracic CT?

PURPOSE

Coronary artery calcification is a frequent incidental finding on thoracic computed tomography (CT) performed for non-cardiac indications. On electrocardiogram-gated cardiac CT, it is an established marker of coronary artery disease and is associated with increased risk of subsequent cardiac events.

MATERIALS AND METHODS

This review discusses the current evidence and guidelines regarding the reporting of coronary artery calcification on non-electrocardiogram-gated thoracic CT performed for non-cardiac indications.

RESULTS

For patients undergoing routine thoracic CT, coronary artery calcification is associated with an increased risk of myocardial infarction and mortality. Coronary artery calcification can be accurately assessed on non-gated thoracic CT compared to gated CT. Guidelines support the reporting of coronary artery calcification on thoracic CT. However, radiologist opinions vary. The identification of coronary artery calcification on thoracic CT may identify patients with previously unknown coronary artery disease. For asymptomatic patients this may trigger an assessment of modifiable cardiovascular risk factors and guide the appropriate use of preventative medications.

CONCLUSION

Future research will address whether changing management based on calcification on thoracic CT will improve outcomes and automated assessment of calcification using machine learning techniques.

KEY POINTS

· Coronary artery calcification is a frequent incidental finding on thoracic CT.. · The presence and severity of coronary artery calcification is associated with cardiac outcomes and mortality.. · Reporting coronary artery calcification on thoracic CT is supported by national and international guidelines..

CITATION FORMAT

· Williams MC, Llewellyn O, . What Should We Do About Coronary Calcification on Thoracic CT?. Fortschr Röntgenstr 2022; 194: 833 - 840.

Radiologist opinions regarding reporting incidental coronary and cardiac calcification on thoracic CT

Objectives

Coronary and cardiac calcification are frequent incidental findings on non-gated thoracic computed tomography (CT). However, radiologist opinions and practices regarding the reporting of incidental calcification are poorly understood.

Methods

UK radiologists were invited to complete this online survey, organised by the British Society of Cardiovascular Imaging (BSCI). Questions included anonymous information on subspecialty, level of training and reporting practices for incidental coronary artery, aortic valve, mitral and thoracic aorta calcification.

Results

The survey was completed by 200 respondents: 10% trainees and 90% consultants. Calcification was not reported by 11% for the coronary arteries, 22% for the aortic valve, 35% for the mitral valve and 37% for the thoracic aorta. Those who did not subspecialise in cardiac imaging were less likely to report coronary artery calcification (p = 0.005), aortic valve calcification (p = 0.001) or mitral valve calcification (p = 0.008), but there was no difference in the reporting of thoracic aorta calcification. Those who did not subspecialise in cardiac imaging were also less likely to provide management recommendations for coronary artery calcification (p < 0.001) or recommend echocardiography for aortic valve calcification (p < 0.001), but there was no difference for mitral valve or thoracic aorta recommendations.

Conclusion

Incidental coronary artery, valvular and aorta calcification are frequently not reported on thoracic CT and there are differences in reporting practices based on subspeciality.

Advances in knowledge

On routine thoracic CT, 11% of radiologists do not report coronary artery calcification. Radiologist reporting practices vary depending on subspeciality but not level of training.

Automated coronary calcium scoring using deep learning with multicenter external validation

Coronary artery disease (CAD), the most common manifestation of cardiovascular disease, remains the most common cause of mortality in the United States. Risk assessment is key for primary prevention of coronary events and coronary artery calcium (CAC) scoring using computed tomography (CT) is one such non-invasive tool. Despite the proven clinical value of CAC, the current clinical practice implementation for CAC has limitations such as the lack of insurance coverage for the test, need for capital-intensive CT machines, specialized imaging protocols, and accredited 3D imaging labs for analysis (including personnel and software). Perhaps the greatest gap is the millions of patients who undergo routine chest CT exams and demonstrate coronary artery calcification, but their presence is not often reported or quantitation is not feasible. We present two deep learning models that automate CAC scoring demonstrating advantages in automated scoring for both dedicated gated coronary CT exams and routine non-gated chest CTs performed for other reasons to allow opportunistic screening. First, we trained a gated coronary CT model for CAC scoring that showed near perfect agreement (mean difference in scores = -2.86; Cohen's Kappa = 0.89, P < 0.0001) with current conventional manual scoring on a retrospective dataset of 79 patients and was found to perform the task faster (average time for automated CAC scoring using a graphics processing unit (GPU) was 3.5 ± 2.1 s vs. 261 s for manual scoring) in a prospective trial of 55 patients with little difference in scores compared to three technologists (mean difference in scores = 3.24, 5.12, and 5.48, respectively). Then using CAC scores from paired gated coronary CT as a reference standard, we trained a deep learning model on our internal data and a cohort from the Multi-Ethnic Study of Atherosclerosis (MESA) study (total training n = 341, Stanford test n = 42, MESA test n = 46) to perform CAC scoring on routine non-gated chest CT exams with validation on external datasets (total n = 303) obtained from four geographically disparate health systems. On identifying patients with any CAC (i.e., CAC ≥ 1), sensitivity and PPV was high across all datasets (ranges: 80-100% and 87-100%, respectively). For CAC ≥ 100 on routine non-gated chest CTs, which is the latest recommended threshold to initiate statin therapy, our model showed sensitivities of 71-94% and positive predictive values in the range of 88-100% across all the sites. Adoption of this model could allow more patients to be screened with CAC scoring, potentially allowing opportunistic early preventive interventions.

Correlation of atherosclerosis and osteoarthritis in ancient Egypt: A standardized evaluation of 45 whole-body CT examinations

OBJECTIVE

To correlate atherosclerosis (Ath) and osteoarthritis (OA) in mummies from ancient Egypt.

MATERIALS

Whole-body CT examinations of 23 mummies from the Ägyptisches Museum und Papyrussammlung, Berlin, Germany, and 22 mummies from the Museo Egizio, Turin, Italy.

METHODS

Ath was assessed in five anatomical regions by means of preserved arterial calcifications. OA was assessed using the Kellgren and Lawrence (1957) classification.

RESULTS

Statistical analysis revealed no correlation between Ath and total OA. A significant association was found for Ath and the upper limb group for OA grade >1 and for Ath and the lower limb group, consisting mainly of the hip and knee, for OA grade >2 OA.

CONCLUSIONS

The association of Ath and advanced OA of the hip and knee is comparable in prevalence to those reported in recent clinical studies, despite the low life expectancy and the different environment and lifestyle of the ancient Egyptians.

SIGNIFICANCE

This is the first study to correlate findings of Ath and OA in ancient Egypt statistically. The diseases of Ath and OA are common ailments with enormous and increasing impacts on public health.

LIMITATIONS

The large number of cardiovascular diseases was indicated only by arterial calcifications that resisted the post-mortem changes of the mummification process. Also, the assessed OA was on radiological OA.

SUGGESTIONS FOR FURTHER RESEARCH

Genomic studies of ancient Egyptian mummies may reveal genetic risk factors for Ath and OA that could be shared in ancient and modern populations.

Reporting incidental coronary, aortic valve and cardiac calcification on non-gated thoracic computed tomography, a consensus statement from the BSCI/BSCCT and BSTI

Incidental coronary and cardiac calcification are frequent findings on non-gated thoracic CT. We recommend that the heart is reviewed on all CT scans where it is visualised. Coronary artery calcification is a marker of coronary artery disease and it is associated with an adverse prognosis on dedicated cardiac imaging and on non-gated thoracic CT performed for non-cardiac indications, both with and without contrast. We recommend that coronary artery calcification is reported on all non-gated thoracic CT using a simple patient-based score (none, mild, moderate, severe). Furthermore, we recommend that reports include recommendations for subsequent management, namely the assessment of modifiable cardiovascular risk factors and, if the patient has chest pain, assessment as per standard guidelines. In most cases, this will not necessitate additional investigations. Incidental aortic valve calcification may also be identified on non-gated thoracic CT and should be reported, along with ancillary findings such as aortic root dilation. Calcification may occur in other parts of the heart including mitral valve/annulus, pericardium and myocardium, but in many cases these are an incidental finding without clinical significance.

Coronary artery calcification is common on nongated chest computed tomography imaging

BACKGROUND

Coronary artery calcification as assessed by computed tomography (CT) is a validated predictor of cardiovascular risk, whether identified on a dedicated cardiac study or on a routine non-gated chest CT. The prevalence of incidentally detected coronary artery calcification on non-gated chest CT imaging and consistency of reporting have not been well characterized.

HYPOTHESIS

Coronary calcification is present on chest CT in some patients not taking statin therapy and may be under-reported.

METHODS

Non-gated chest CT images dated 1/1/2012 to 1/1/2013 were retrospectively reviewed. Demographics and medical history were obtained from charts. Patients with known history of coronary revascularization and/or pacemaker/defibrillator were excluded. Two independent readers with cardiac CT expertise evaluated images for the presence and anatomical distribution of any coronary calcification, blinded to all clinical information including CT reports. Original clinical CT reports were subsequently reviewed.

RESULTS

Coronary calcification was identified in 204/304 (68%) chest CTs. Patients with calcification were older and had more hyperlipidemia, smoking history, and known coronary artery disease. Of patients with calcification, 43% were on aspirin and 62% were on statin medication at the time of CT. Coronary calcification was identified in 69% of reports when present.

CONCLUSIONS

A high prevalence of coronary calcification was found in non-gated chest CT scans performed for non-cardiac indications. In one-third, coronary calcification was not mentioned in the clinical report when actually present. In this population of patients with cardiac risk factors, standard reporting of the presence of coronary calcification may provide an opportunity for risk factor modification.