Image-Derived Modeling to Assess Coronary Proximity in Patients Undergoing Transcatheter Pulmonary Valve Replacement With Self-Expanding Valves.

Abstract

Background: The potential for coronary artery compression (CC) during transcatheter pulmonary valve replacement (TPVR) using self-expanding valves (SEV) is not fully understood, yet anecdotal reports suggest that this risk exists.

Aims and methods: We performed a retrospective cohort study of patients evaluated for SEV-TPVR to evaluate the relationship between the right ventricular outflow tract (RVOT) and coronary arteries (CA). CT-derived segmentations of the RVOT and CA were created using machine learning. A 2D map of the distance between the RVOT surface and CA, in systole and diastole, was created. In the subset of patients with post-procedural CTA, the distance before and after TPVR was measured.

Results: Forty-two individuals underwent screening for SEV-TPVR, of which 83% (n = 35) had SEV implanted (Harmony = 24; Alterra = 11). Median age was 22.9 years (range 12-60) and 76% had tetralogy of Fallot (TOF). There was no significant change in the distance between the RVOT and LCA between diastole and systole (p = 0.31), yet the RVOT area nearest to the LCA displaced proximally by 11 mm (IQR: 5.6-19.9) in systole. In 8 patients with pre- and post-TPVR CTA, no statistically significant differences were observed in the RVOT-to-LCA relation after intervention. The distance to the LCA was smaller in pulmonary stenosis/atresia patients than those with TOF (median distance 1.2 and 2.1 mm, respectively; p = 0.185).

Conclusion: The RVOT area in closest proximity to LCA is dynamic and should be considered when planning TPVR. Special attention should be given to patients with a diagnosis of pulmonary stenosis/atresia.