Calcium Scores in the Risk Assessment of an Asymptomatic Population, Implications for Airline Pilots

Background: This study evaluated whether coronary artery calcium score (CACS) improved cardiovascular disease risk prediction when compared to the New Zealand Cardiovascular Risk Charts (NZ-CRC), and describes the potential utilization of CACS in cardiovascular disease (CVD) risk assessment of pilots. Methods: A cross-sectional study was performed among asymptomatic patients who underwent coronary computed tomography angiography at Pacifi c Radiology Wellington, New Zealand, between August 2007 and July 2012 and had their CACS and CVD risk score calculated. Receiver-operating characteristics (ROC) analyses were used to measure the accuracy of the NZ-CRC and CACS. Reclassifi cation analyses were performed to examine the net reclassification improvement (NRI) of CACS when compared to NZ-CRC. Results: Over a 5-yr study period, 237 male asymptomatic patients with ages ranging from 30 to 69 yr with a mean (SD) of 53.24 (8.18) yr, were included. The area under the ROC curves (AUC) (95% CI) for CACS and NZ-CRC were 0.88 (0.83-0.93) and 0.66 (0.59-0.73), respectively. The NRI (95% CI) of the calcium scores was 0.39 (0.17-0.62). CACS should be assessed in pilots with 5-yr CVD risk scores of 5 – 10% and 10 – 15%. Conclusion: CACS has a better accuracy than the NZ-CRC and reclassified a considerable proportion of asymptomatic patients into correct cardiovascular risk categories. An approach on how the CACS should be employed in the cardiovascular risk assessment of airline pilots is noted in this paper.