Coronary Computed Tomography Angiography Demonstrates a High Burden of Coronary Artery Disease Despite Low‐Risk Nuclear Studies in Pre–Liver Transplant Evaluation

Abstract

We investigated the presence and severity of coronary artery disease (CAD) in orthotopic liver transplantation (OLT) candidates using coronary artery calcium score (CACS) and coronary computed tomography angiography (CCTA) as compared with the prevalence of normal and abnormal single-photon emission computed tomography (SPECT) myocardial perfusion imaging (MPI). A total of 140 prospective OLT candidates without known CAD underwent coronary artery calcium (CAC) scans with (n = 77) or without CCTA and coronary computed tomography angiography-derived fractional flow reserve (FFR CT ; n = 57) using a dual-source computed tomography (CT) and were followed for 2.6 ± 1.4 years. Coronary plaque was quantified using the segment-involvement score (SIS) and segment stenosis score (SSS). The mean age was 59 ± 6 years, and 65.0% of patients were male. Mean Agatston CACS was 367 ± 653, and 15.0% of patients had CACSs of 0; 83.6% received a SPECT MPI, of which 95.7% were interpreted as normal/probably normal. By CCTA, 9.1% had obstructive CAD (≥70% stenosis), 67.5% had nonobstructive CAD, and 23.4% had no CAD. Nonobstructive CAD was diffuse with mean SIS 3.0 ± 2.9 and SSS 4.5 ± 5.4. Only 14 patients had high risk-findings (severe 3v CAD, n = 4, CACS >1000 n = 10) that prompted X-ray angiography in 3 patients who had undergone CCTA, resulting in revascularization of a high-risk obstruction in 1 patient who had a normal SPECT study. Patients with end-stage liver disease have a high prevalence of nonobstructive CAD by CCTA, which is undiagnosed by SPECT MPI, potentially underestimating cardiovascular risk. Deferring X-ray angiography unless high-risk CCTA findings are present is a potential strategy for avoiding unnecessary X-ray angiography.

Coronary artery calcium on standard chest computed tomography predicts cardiovascular events after liver transplantation

“…Several studies have suggested the potential role of coronary artery calcium (CAC) to estimate the cardiovascular risk of patients undergoing LT [4][5][6][7]. Other investigations have compared CAC evaluation to non-invasive stress tests (such as exercise testing or nuclear studies) demonstrating its higher correlation with the burden of coronary artery disease [8,9]. Quantification of CAC usually requires dedicated chest computed tomography (CT) scans that are thin-layer (usually slices of 3 mm) and electrocardiography (ECG) gated, in order to minimize motion artifacts from beating heart and to provide better quality images.…”

Preoperative Evaluation of Coronary Artery Disease in Liver Transplant Candidates: Many Unanswered Questions in Clinical Practice

“…Additionally, in a recent study, when CCTA findings were correlated with SPECT MPI, nearly all ESLD patients were found having a normal SPECT MPI result. This finding indicates that CCTA may serve as a more effective gatekeeper to improve efficiency of referral to CA [57]. The authors also reported high eligibility for FFR-CT analysis due to acceptable CT image quality in these patients with impaired hemodynamic profiles, while this issue is also being addressed by the ongoing CRASCH-Liver trial (www.clinicaltrials.gov Identifier: NCT04089969).…”

Liver transplantation for non-alcoholic fatty liver disease: indications and post-transplant management

“…Invasive coronary angiography is the gold-standard test to identify significant CHD in the general population, but currently, in LT candidates, studies are inconclusive and not able to predict the impact of asymptomatic pre-LT CV abnormalities on long-term outcomes [ 39 , 40 ]. Coronary computed tomography angiography (CCTA) is a non-invasive test valid for assessing the risk of CHD in LT candidates, although no studies are comparing it with invasive coronary angiography (ICA) in this population [ 41 ]. CCTA alone does not provide a functional assessment of coronary stenosis, which can be obtained by integrating this examination with fractional flow reserve obtained from computed tomography in this population [ 42 ].…”