Pacemaker implantation in familial amyloid polyneuropathy: when and for whom?

BACKGROUND: Despite the important role of cardiac pacing in preventing syncope and sudden cardiac death in familial amyloid polyneuropathy (FAP), we lack clear guidelines as to the ideal timing and indications for permanent pacemaker implantation.
PURPOSE: The purpose of this study was to evaluate the ideal timing for pacemaker implantation in FAP patients submitted to liver transplantation.
METHODS: Retrospective study of 258 FAP patients submitted to liver transplantation between 1992 and 2012. Comparison of three groups: (A) patients without pacemaker (N = 122); (B) patients submitted to pacemaker implantation after liver transplantation, with documented conduction disorders (N = 73); and (C) patients submitted to "prophylactic" pacemaker implantation before transplantation, (N = 73). Patients were followed up for 12.2 ± 6.7 years.
RESULTS: The majority of patients (57%) were referred for pacemaker implantation, which occurred before liver transplantation in 50% of cases. Patients who required pacemaker after transplantation presented significantly higher Machado-Joseph Score during pre-transplant evaluation than those who did not require pacemaker (24 ± 10 vs 20 ± 10, p = .025), and also exhibited higher levels of hepatic cytolysis enzymes and hyperbilirubinemia. The most common indication for permanent pacemaker was first degree atrioventricular block, with a mean time between transplantation and pacemaker implantation of 8.7 ± 4.2 years. During long-term follow-up, all-cause mortality was 27% and was lowest in the group submitted to pacemaker implantation only after liver transplantation (p = 0.002).
CONCLUSION: The majority of FAP patients submitted to liver transplantation will need a pacemaker at some time of follow-up. However, it seems that there is no benefit in "prophylactic" cardiac pacing before liver transplantation.