Coronary artery calcification on non-gated CT thorax tied to risk of cardiovascular disease, death: Study

The study found that patients aged 40-70 years without known cardiovascular disease but with CAC on NC-NECG-CTT were at higher risk of cardiovascular disease events than those without CAC. CAC (Agatston) score above 100 in these patients confers a 5.7-fold increase in short-term CVD events risk.

Coronary artery calcification is a marker of coronary atherosclerosis, strongly linked with major CVD events in asymptomatic people. CACS (CAC scoring) is the best-established imaging test for CVD risk stratification. Non-gated CT scans allow for either quantitative or semiquantitative CACS, with a high correlation to gated CT studies. Still, there have been concerns regarding the cost-effectiveness and availability of systematic screening with ECG-gated CAC scanning.

Against the above background, Maria T. A. Wetscherek, from Cambridge University Hospitals NHS Foundation Trust in Cambridge, UK, and colleagues aimed to assess CAC on non-contrast non-ECG-gated CT thorax. Also, they evaluated its correlation with short-term risk of cardiovascular disease events and death.

For this purpose, the researchers conducted a single-institution retrospective study that included participants who underwent NC-NECG-CTT over six months. Those with known CVD were excluded. CAC presence was quantified and assessed by CACS (Agatston score). CAA severity was defined as severe (> 400), moderate (100–400), or mild (< 100).

CVD events, including myocardial infarction, CVD death, ischemic stroke, acute peripheral atherosclerotic ischaemia, revascularisation procedures, and all-cause mortality, were recorded over a median of 3.5 years. The team performed Cox proportional-hazards regression modelling, including age, gender, CACS, and CVD risk factors (diabetes mellitus, hypertension, smoking, family history of CVD, dyslipidemia).

The researchers reported the following findings:

• Of the total 717 eligible cases, 45% had CAC.
• There was only one CVD event in patients without CAC, compared to 26 CVD events, including five deaths in CAC patients.
• The severity and presence of CAC correlated with CVD events.
• A CACS > 100 was significantly associated with CVD events, a hazard ratio (HR) of 5.74, and all-cause mortality, HR 1.7.
• Ever-smokers with CAC had a remarkably higher risk for all-cause mortality than never-smokers. Still, smoking status was not an independent predictor for CVD events in any subgroup category of CAC severity.

"Our findings confirmed that CAC on routine clinically-indicated CT thorax can be used for the identification of those at greater risk of future CVD events," the researchers wrote.

"Our study, which is the first to investigate the prognostic value of CACS cut-off 100 for CV events and death, supports the current guidelines recommending reporting of CAC on all thoracic CTs to ease adequate risk modification and preventive treatment," they conclude.

Reference:

Wetscherek, M.T.A., McNaughton, E., Majcher, V. et al. Incidental coronary artery calcification on non-gated CT thorax correlates with risk of cardiovascular events and death. Eur Radiol (2023). https://doi.org/10.1007/s00330-023-09428-z