UCLA

Guidelines to evaluate patients for underlying coronary artery disease (CAD) during pre-operative evaluation for orthotopic liver transplantation (OLT) are conflicting. Cardiac catheterization is not without risk in end-stage liver disease patients. No study to date has looked at the utility of non-ECG-gated chest CT scans in the pre-liver transplant population. Our hypothesis was that by calculating coronary artery calcium scores (CACS) from chest CT scans ordered during the liver transplant workup, it may be possible to more accurately identify patients who would benefit from invasive angiography. 953 patients who underwent coronary angiography as part of their OLT workup from 2006 to 2015 at a single academic medical center were considered. Charts were randomly selected and reviewed for the presence of a chest CT performed prior to coronary angiography during the OLT workup. Agatston and Weston scores were calculated for each vessel and summed for each patient. CACS results were compared to coronary angiography findings. 9 out of 54 patients were found to have obstructive coronary artery disease by angiography. ROC analysis demonstrated that an Agatston score of 251 and a Weston score of 6 maximized sensitivity and specificity for detection of obstructive coronary disease. An Agatston score < 4 or Weston score < 2 excluded the presence of obstructive CAD; using these thresholds, 13 patients (24%) or 15 patients (28%), respectively, could have avoided catheterization without missing significant CAD. Our data identify the strength of calcium scoring in ruling out coronary disease in patients being evaluated for OLT. Calcium scoring from non-ECG gated CT studies may be integrated into preoperative algorithms to rule out obstructive CAD and help avoid invasive angiography in high risk patients.