Hemolysis After Transcatheter Pulmonary Valve Implantation Associated With Residual Shunt Flow.

BACKGROUND

Transcatheter pulmonary valve implantation (TPVI) is an established treatment for severe pulmonary regurgitation after repaired tetralogy of Fallot, whereas clinically significant hemolysis is rare.

CASE SUMMARY: A 39-year-old man with repaired tetralogy of Fallot developed severe pulmonary regurgitation with progressive right ventricular enlargement. TPVI using a self-expandable Harmony valve was successfully performed. Postprocedural dark-red urine and laboratory findings confirmed hemolysis. Multimodality imaging revealed a coronary artery-right ventricular fistula and residual ventricular septal defect adjacent to the valve. High-velocity shunt flow impinging on the prosthesis was considered the mechanism. Hemolysis resolved with blood pressure control alone.

DISCUSSION: Residual shunt lesions adjacent to the right ventricular outflow tract may cause mechanical hemolysis after TPVI by generating localized high-shear stress. This case highlights the importance of comprehensive multimodality imaging before TPVI.

TAKE-HOME MESSAGE: Residual shunt flow adjacent to the right ventricular outflow tract may cause mechanical hemolysis after TPVI.