Abstract 20997: In Postoperative Conotruncal Anomalies Patients Differential Branch Pulmonary Artery Regurgitant Fraction is a Function of Differential Pulmonary Vascular Resistance and Pulmonary Arterial Properties
Introduction: Repaired conotruncal anomaly patients frequently have residual branch pulmonary artery (BPA) stenosis or size differences associated with differential BPA regurgitation.
Hypothesis: In patients with residual BPA stenosis and size discrepancy, differential BPA regurgitation correlates with differential pulmonary vascular resistance (PVR).
Methods: We retrospectively reviewed 76 consecutive cardiac magnetic resonance (CMR) studies for BPA size and Phase-Contrast Magnetic Resonance data, including thirteen consecutive patients who underwent both CMR and catheterization within 1 year of each other without an intervention in the interim.
Results: Thirty of the 76 pts had either BPA stenosis or significant size discrepancy. Whereas previous studies have shown an increased regurgitant fraction (RF) in the left pulmonary artery, patients with BPA stenosis or size discrepancy showed no significant difference between right and left BPA RF (30% vs 30%, p=0.985). However, there was a significantly increased RF of the larger vs smaller BPA (39% vs 21%, p<0.001) resulting in fairly balanced net flows (63% vs 37%, p<0.001). Retrospective review of patients who underwent both CMR and catheterization provides support for the above findings and validates differential BPA RF as strongly correlating with differential PVR (r= 0.8364, p<0.001). Three of the catheterization patients had more regurgitation and elevated unilateral PVR (8.1 - 11.0 Wu) in the larger BPA in combination with at least one-third of the net pulmonary blood flow directed toward the smaller stenotic BPA. All three patients underwent stent implantation in the smaller BPA.
Conclusion: Differential BPA RF is a function of BPA anatomy and PVR. In the setting of BPA stenosis or size discrepancy, net flows will not identify unilateral increases in PVR which affects the indication and timing for repair of BPA stenosis.
- © 2010 by American Heart Association, Inc.