Complete heart block and subsequent sudden cardiac death following transcatheter tricuspid valve replacement in a heart transplant patient: a case report.

Background: Tricuspid regurgitation (TR) is a common valvular complication following heart transplantation. Transcatheter tricuspid valve replacement exists as a novel treatment option. However, as with any procedure, important complications can occur and warrant discussion. Case summary: A 46-year-old woman, status post-orthotopic heart transplant (HT), developed symptomatic severe TR. She underwent transcatheter tricuspid valve replacement (TTVR; EVOQUE system, Edwards Lifesciences) and was subsequently presented to the hospital following a syncopal event. She was found to be in cardiogenic shock with complete heart block on an electrocardiogram that degenerated into sudden cardiac death. Although the valve was well-seated, autopsy revealed areas of focal necrosis where the bioprosthetic valve was seated in the region of the atrioventricular node and His bundle. Discussion: This is the first case report of a complication of transcatheter tricuspid valve replacement in a heart transplant patient resulting in complete heart block and sudden cardiac death. While TTVR may be a good treatment option for select patients in this high-risk group, conduction system damage is a potential complication given the anatomy of the region and requires very close monitoring. This case further highlights the unique physiology of HT patients and illustrates the fact that bradyarrhythmias are often poorly tolerated and potentially lethal.