Should coronary artery calcification assessment with low-dose thoracic computed tomography be extended to non-smoking liver transplant recipients?

We read with great interest the article by Caballeros Lam et al. The authors show that low-dose thoracic computed tomography (CT) enables the detection of severe coronary artery calcifications in liver transplant recipients. As expected, severe coronary artery calcifications were associated with adverse cardiovascular events. The authors conclude that low-dose CT should be performed for lung cancer screening and for cardiovascular risk stratification in liver transplant recipients who smoke. Their findings are similar to the recently published from the Danish Comorbidity in Liver Transplant Recipients (DACOLT) study, although DACOLT used coronary CT angiography and these examinations are not interchangeable. DACOLT data show that living with a transplanted liver is associated with higher odds of any coronary atherosclerosis (odds ratio [OR]: 2.2), obstructive coronary atherosclerosis (OR: 2.7), and obstructive-extensive coronary atherosclerosis (OR: 3.9). Moreover, among individuals with any coronary atherosclerosis, liver transplant recipients had higher odds of having high-risk plaque than population control subjects (OR: 2.1). DACOLT investigators were unable to find an association of tobacco with coronary atherosclerosis, although this was probably related to limited power and confounding factors. Koshy et al. were also unable to find a significant association between tobacco consumption and progression of coronary atherosclerosis, although this could be expected due to the low number of liver transplant recipients they studied (n=30).