Outflow tract geometries are associated with adverse outcome indicators in repaired tetralogy of Fallot

Wan-Chen Shen; Chun-An Chen; Chung-I Chang; Yih-Sharng Chen; Shu-Chien Huang; Mei-Hwan Wu; Jou-Kou Wang

doi:10.1016/j.jtcvs.2020.09.072

Outflow tract geometries are associated with adverse outcome indicators in repaired tetralogy of Fallot

J Thorac Cardiovasc Surg. 2021 Jul;162(1):196-205. doi: 10.1016/j.jtcvs.2020.09.072. Epub 2020 Sep 22.

Authors

Wan-Chen Shen¹, Chun-An Chen², Chung-I Chang³, Yih-Sharng Chen⁴, Shu-Chien Huang⁴, Mei-Hwan Wu⁵, Jou-Kou Wang⁵

Affiliations

¹ Department of Pediatrics, Fu Jen Catholic University Hospital, Fu Jen Catholic University, New Taipei, Taiwan; Department of Cardiology, National Taiwan University Children's Hospital, Taipei, Taiwan.
² Department of Cardiology, National Taiwan University Children's Hospital, Taipei, Taiwan. Electronic address: chenca@ntu.edu.tw.
³ Department of Surgery, National Taiwan University Hospital, Taipei, Taiwan; Department of Surgery, Mackay Memorial Hospital, Taipei, Taiwan.
⁴ Department of Surgery, National Taiwan University Hospital, Taipei, Taiwan.
⁵ Department of Cardiology, National Taiwan University Children's Hospital, Taipei, Taiwan.

PMID: 33097218
DOI: 10.1016/j.jtcvs.2020.09.072

Abstract

Objectives: A wide variety of right ventricular outflow tract (RVOT) and pulmonary artery (PA) geometries has been reported in patients with repaired tetralogy of Fallot (rTOF). We aimed to investigate the associations between RVOT/PA geometries and outcome indicators in a large rTOF cohort receiving non-conduit repair.

Methods: Three-dimensional magnetic resonance angiographic images of 206 patients with rTOF who had a pulmonary regurgitation (PR) fraction ≥20% were reviewed. Patients' RVOT geometry was quantitatively classified into 4 distinct shapes (tubular, hourglass, pyramid, and inverted trapezoid). Bilateral PA size discrepancy was defined as the diameter of the smaller side being less than 70% of that of the bigger side.

Results: Based on lateral projection of the 3-dimensional images, patients with an inverted trapezoid-shaped RVOT had the smallest RV end-diastolic volume index (EDVi) (108.7 ± 24.3 mL/m²) and pulmonary valve annulus diameter, and shortest QRS duration, whereas those with a pyramid-shaped RVOT had the largest RV EDVi (161.0 ± 44.6 mL/m²) and pulmonary valve annulus diameter. Similar trends of differences were also observed if such classifications were based on the frontal projections. Multivariable analysis revealed that RVOT shapes, subvalvular diameter, PR fraction, QRS duration, and the presence of bilateral PA size discrepancy were independent determinants of RV EDVi. Furthermore, having bilateral PA size discrepancy (25.2%) was independently associated with lower peak oxygen consumption (P = .041).

Conclusions: Distinct RVOT morphologies and branch PA size discrepancy are associated with variations in RV remodeling and exercise capacity in patients with rTOF. These findings may aid decision-making regarding reintervention for PR and branch PA size discrepancy.

Keywords: branch pulmonary artery size discrepancy; cardiovascular magnetic resonance; exercise capacity; right ventricular outflow tract morphology; tetralogy of Fallot.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Adolescent
Adult
Exercise Tolerance / physiology
Female
Heart Ventricles* / diagnostic imaging
Heart Ventricles* / pathology
Humans
Magnetic Resonance Imaging
Male
Pulmonary Artery* / diagnostic imaging
Pulmonary Artery* / pathology
Pulmonary Valve Insufficiency / etiology
Pulmonary Valve Insufficiency / physiopathology
Pulmonary Valve Insufficiency / surgery
Tetralogy of Fallot / complications
Tetralogy of Fallot / physiopathology
Tetralogy of Fallot / surgery*
Young Adult