An audit on coronary artery calcium scoring in the mercy university hospital, co. cork, ireland
Authors: Lakhwani B , Kerins D , Pollock A , Khashab A , Chin B 
Published: February 2022

Abstract

Funding Acknowledgements
Type of funding sources: None.

Background
Coronary artery calcium (CAC) testing is an imaging technique used to non-invasively assess calcification within the coronary arteries. It has emerged as a reliable surrogate measure of coronary artery disease where higher risk individuals are more likely to benefit from medications such as aspirin and statins. A high calcium score should prompt further diagnostic tests for coronary artery disease. This was a single centre audit designed to assess the current role and the clinical implications of CAC testing in our university hospital, Ireland.

Methods
This was a retrospective chart review of all patients who underwent CAC testing in MUH from 1st January 2019 to 31st December 2020. Patients were recruited from the CAC database within the hospital radiology department. Demographic data, indication for CAC testing, medication records and results of invasive coronary angiography were obtained from the medical records. Assessment of CAC scores and percentiles from all patients were recorded from the radiology results system.

Results
Of the 218 participants, 48.6% were male and the mean age was 53.7 (± 9.7) years. The most common risk factors were hypercholesterolaemia (65.1%), family history of premature coronary artery disease (48.6%) and hypertension (31.2%). CAC results were as follows: 50.5% had a score of 0, 25.2% had a score of 1-99, 12.4% had a score of 100-399, 6.4% had a score of 400-999, and 5.5% had a score of ≥1000. The most common indications for CAC testing were risk factors (45.5%) and symptoms (38.0%). CAC testing indications were unretrievable on the database for 31 patients (14.2%). CT coronary angiography was performed in 57 patients (26.1%), while 30 patients (13.8%) had invasive coronary angiography. On invasive coronary angiography, 8 patients (3.7%) were reported to have obstructive disease and 25 patients (11.5%) had non-obstructive disease. Following CAC testing, antiplatelet therapy was started in 15 patients (6.9%). Statin therapy was started in 28 patients (12.4%). The maintenance and modification of previous statin therapy was noted in 67 patients (30.3%).

Conclusion
CAC testing is a useful non-invasive diagnostic test which can be used to identify individuals at risk of obstructive coronary artery disease and guide initiation of risk modifying therapy. The cohort of patients currently undergoing CAC testing in our hospital are largely asymptomatic patients with cardiovascular risk factors. The results of these tests led to commencement of risk modifying treatment in less than 20% of patients and only a small proportion of patients required follow-on invasive coronary angiography for further investigation of their coronary artery anatomy. These results show that CAC testing use in our hospital is in line with international guidelines and suggest that the use of CAC testing decreases the requirement for invasive coronary angiography in low-risk, asymptomatic patients.