Comparison of Coronary Calcium in Firefighters With Abnormal Stress Test Findings and in Asymptomatic Nonfirefighters With Abnormal Stress Test Findings

Firefighters are known to have an elevated rate of sudden cardiac death compared to the general population. It is unclear whether this finding is related to underlying cardiovascular risk factors or whether firefighting inherently carries additional risk. Our objective was to determine whether Los Angeles county firefighters have higher coronary artery calcium (CAC) scores and increased atherosclerosis as determined using 64-slice cardiac, multidetector computed tomography. A total of 647 asymptomatic firefighters evaluated as a part of a wellness protocol were referred for cardiac multidetector computed tomography to evaluate abnormal exercise treadmill test findings. They were matched by age and cardiovascular risk factors, with 2,533 asymptomatic subjects undergoing cardiac computed tomography because of abnormal electrocardiographic or exercise treadmill test findings. CAC and the prevalence of obstructive coronary artery disease by vessel were derived. Finally, the predictors of CAC were analyzed using regression analysis. Of the firefighters, 49% had detectable CAC compared to 43% of controls (p = 0.015). Although the lesions were most prevalent in the left anterior descending artery in both groups, more firefighters had any left anterior descending artery stenosis compared to the controls (p <0.0001). The firefighters also had more left main coronary artery lesions than did the controls (p <0.0001). The firefighters had significantly greater CAC scores than did with the controls (p <0.001). Furthermore, the firefighters had significantly greater mean CAC scores (66 ± 8 in firefighters vs 33 ± 4 for controls, p <0.001). Firefighter status was independently associated with a 41-point increase in the CAC score (p <0.001). In conclusion, asymptomatic firefighters had more atherosclerosis and CAC than the matched controls.