Use of mechanical valve prostheses in adults with tetralogy of Fallot

There are limited data about the outcomes mechanical prostheses in adults with tetralogy of Fallot (TOF). The purpose of the study was to describe the incidence of mechanical valve related adverse events (MVRAE), reoperation and all-cause mortality in TOF patients with mechanical valve prostheses.

We reviewed the MACHD (Mayo Adult Congenital Heart Disease) database and identified all adult TOF patients with mechanical valve prostheses, 1990-2017. MVRAE was defined as valve thrombosis, endocarditis, embolic stroke or major bleeding complications.

A total of 44 prostheses were implanted in 29 patients (age 44 ± 13 years; men 18 [62%]), and 10 (36%) patients received multiple mechanical prostheses. The median number of prior sternotomies was 3 (range 2-7). Target intentional normalized ratio (INR) was 2.0-3.0 for patients with isolated mechanical aortic prostheses (n = 12, 41%), 2.5-4.0 for mechanical prostheses in non-aortic positions. There were no surgical deaths, and 10 MVRAE (endocarditis [n = 4], major bleeding complications [n = 5] and valve thrombosis [n = 1]) occurred in 7 (24%) patients during a median follow-up of 11 (5 18) years. The 10-year survival and freedom from reoperation were 87% and 95% respectively.

Surgical mortality and valve thrombosis for mechanical valve prostheses are low presumably due to appropriate patient selection and meticulous anticoagulation. Endocarditis and bleeding complications are major concerns. Further studies are required to determine the appropriate target INR that provides the optimal balance between preventing valve thrombosis and avoiding major bleeding complications mechanical valve prostheses in different positions.