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. Supplementary Information The online version contains supplementary material available at 10.1007/s00330-023-10439-z.


# Checklist item
Location where item is reported Synthesis methods 13a Describe the processes used to decide which studies were eligible for each synthesis (e.g.tabulating the study intervention characteristics and comparing against the planned groups for each synthesis (item #5)).

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13b Describe any methods required to prepare the data for presentation or synthesis, such as handling of missing summary statistics, or data conversions.190-204 13c Describe any methods used to tabulate or visually display results of individual studies and syntheses.190-204 13d Describe any methods used to synthesize results and provide a rationale for the choice(s).If meta-analysis was performed, describe the model(s), method(s) to identify the presence and extent of statistical heterogeneity, and software package(s) used.

190-204
13e Describe any methods used to explore possible causes of heterogeneity among study results (e.g.subgroup analysis, meta-regression).

203-204
13f Describe any sensitivity analyses conducted to assess robustness of the synthesized results.

203-204
Reporting bias assessment 14 Describe any methods used to assess risk of bias due to missing results in a synthesis (arising from reporting biases).

203-204
Certainty assessment 15 Describe any methods used to assess certainty (or confidence) in the body of evidence for an outcome.190-204

Study selection 16a
Describe the results of the search and selection process, from the number of records identified in the search to the number of studies included in the review, ideally using a flow diagram.
Figure 1 16b Cite studies that might appear to meet the inclusion criteria, but which were excluded, and explain why they were excluded.Figure 1 Study characteristics 17 Cite each included study and present its characteristics.

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Risk of bias in studies 18 Present assessments of risk of bias for each included study.Supplementary Table 3 Results of individual studies 19 For all outcomes, present, for each study: (a) summary statistics for each group (where appropriate) and (b) an effect estimate and its precision (e.g.confidence/credible interval), ideally using structured tables or plots.

Location
where item is reported confidence/credible interval) and measures of statistical heterogeneity.If comparing groups, describe the direction of the effect.

TABLE 1B :
(1) Research question stated (2) Study population defined (3) Participation rate > 50% (4) Subjects selected from the same or similar population with inclusion and exclusion criteria (5) Sample size justification or power description, or variance and effect estimates (6) Exposure(s) of interest measured before outcome measurement?(7)Sufficienttimeframe (8): Exposure measured as categories or continuously in relation to the outcome?(9)Independent variables clearly defined and measured in all participants (10) Exposure measured more than once (11) Outcome measures clearly defined (12) Outcome assessors blinded (13) Loss to follow up 20% or less (14) Adjusted statistics for confounding variables; Y, yes; N, no; ?, unclear; NA, not assessable

Table 4 . Titles, Authors and Years of Studies Included in the Systematic Review and Meta-Analysis
Computed Tomography on lung cancer screening is useful for adjuvant comorbidity diagnosis in developing countries Dirrichs et al.Extracoronary Thoracic and Coronary Artery Calcifications on Chest CT for Lung Cancer Screening Douthit et al.Clinical Impact of reporting Coronary Artery Calcium Scores of Non-Gated Computed Tomography on Statin Management Einstein et al.Agreement of Visual Estimation of Coronary Artery Calcium From Low-Dose CT Attenuation Correction Scans in Hybrid PET/CT and SPECT/CT With Standard Agatston Score Ezponda et al.Chest CT-assessed comorbidities and all-cause mortality risk in COPD patients in the BODE cohort Relationship of Coronary Calcium on Standard Chest CT Scans With Mortality Hutt et al.Coronary calcium screening with dual-source CT: reliability of ungated, high-pitch chest CT in comparison with dedicated calcium-scoring CT Itani et al.Coronary artery calcification detected by a mobile helical computed tomography unit and future cardiovascular death: 4-year follow-up of 6120 asymptomatic Japanese.Jacobs et al.Unrequested information from routine diagnostic chest CT predicts future cardiovascular events Johsnon et al.Coronary Artery Calcification Is Often Not Reported in Pulmonary CT Angiography in Patients With Suspected Pulmonary Embolism: An Opportunity to Improve Diagnosis of Acute Coronary Syndrome Khan et al.Visually estimated coronary artery calcium score improves SPECT-MPI risk stratification Uretsky et al.The Interplay of Physician Awareness and Reporting of Incidentally Found Coronary Artery Calcium on the Clinical Management of Patients Who Underwent Noncontrast Chest Computed Tomography Vakil et al.Predictive Value of Coronary Artery Calcium in Patients Receiving Computed Tomography Pulmonary Angiography for Suspected Pulmonary Embolism in the Emergency Department Van Assens et al.Automatic coronary calcium scoring in chest CT using a deep neural network in direct comparison with non contrast cardiac CT: A validation study Van der Bijl et al.Coronary or thoracic artery calcium score in provoked and unprovoked pulmonary embolism: a case-control stud Velangi et al.Impact of the 2016 SCCT/STR guidelines for coronary artery calcium scoring on noncardiac chest CT scans on lung cancer screening CT reporting Wang et al.Coronary Artery Calcifications and Cardiac Risk after Radiation Therapy for Stage III Lung Cancer Wang et al.Incremental Value of Noncontrast Chest Computed Tomography-derived Parameters in Predicting Subclinical Carotid Atherosclerosis Wenning et al.Coronary artery calcium burden, carotid atherosclerotic plaque burden, and myocardial blood flow in patients with endstage renal disease: A non-invasive imaging study combining PET/CT and 3D ultrasound West et al.Significance of Coronary Artery Calcium Found on Non−Electrocardiogram-Gated Computed Tomography During Preoperative Evaluation for Liver Transplant Williams et al.Coronary Artery Calcification on Thoracic Computed Tomography Is an Independent Predictor of Mortality in Patients Coronary artery calcification is increased in patients with COPD and associated with increased morbidity and mortality Wu et al.Coronary Arterial Calcification on Low-Dose Ungated MDCT for Lung Cancer Screening: Concordance Study with Dedicated Cardiac CT Xia et al.High-pitch dual-source CT for coronary artery calcium scoring: A head-to-head comparison of non-triggered chest versus triggered cardiac acquisition Yang et al.Nongated Computed Tomography Predicts Perioperative Cardiovascular Risk in Lung Cancer Surgery Yu et al.Incidentally identified coronary artery calcium on non-contrast CT scan of the chest predicts major adverse cardiac events among hospital inpatents Zimmerman et al.Coronary calcium scoring assessed on native screening chest CT imaging as predictor for outcome in COVID-19: An analysis of a hospitalized German cohort Zorzi et al.Coronary artery calcium on standard chest computed tomography predicts cardiovascular events after liver transplantation