Detection of Discrete Anatomical Features by CT Angiography as Predictors of Coronary Compression in Transcatheter Pulmonary Valve Replacement Patients

Background
Transcatheter pulmonary valve replacement (TCPVR) is used to rehabilitate the right ventricular outflow tract in patients with congenital heart disease. A potential complication of TCPVR is compression of the coronary arteries, which can cause ischemia and infarction. Analysis of patient CT angiography (CTA) prior to TCPVR may help identify those at risk.

Methods
Of the 327 patients who underwent coronary artery balloon compression testing as part of invasive evaluation prior to TCPVR at UCLA between 2010 and 2018, 49 underwent pre-procedural chest CTA and were included in this analysis. Several measurements were taken using the scans, including coronary artery proximity to the TCPVR landing zone and landing zone proximity to the sternum.

Results
37 of the 49 patients (76%) had a distance >3 mm between the intended TCPVR landing zone and the nearest coronary artery. This group had no evidence of coronary compression with balloon testing and had a 100% TCPVR success rate. The 12 patients (24%) with a coronary to landing zone distance ≤3 mm were further stratified according to two additional anatomical risk factors that were individually found to significantly predict the outcome by logistic regression: the distance between the intended landing zone and the sternum (p<0.05), and the presence of anomalous coronary artery origin or course (p<0.05). The results of this analysis are presented in Figure 1.

Conclusions
Coronary compression risk increases in a graded fashion depending on the number of anatomical risk factors present in the patient. Analysis of coronary artery location and course on CTA prior to TCPVR can be of value in determining compression risk.