Prophylactic pacemaker implantation in familial amyloid polyneuropathy

Area of Science:

• Cardiology
• Neurology
• Genetics

Background:

• Familial amyloid polyneuropathy (FAP) is an autosomal dominant disorder.
• FAP patients exhibit a high incidence of conduction disorders and sudden cardiac death risk.
• Prophylactic cardiac pacing in asymptomatic FAP patients is under investigation for its benefits.

Purpose of the Study:

• To assess conduction abnormalities in a large cohort of FAP patients.
• To determine the incidence of high-degree atrioventricular (AV) block in FAP patients receiving prophylactic pacemakers (PM).

Main Methods:

• Retrospective evaluation of 262 FAP patients from 1999 to 2010.
• Prophylactic PM implantation criteria included specific His-ventricular intervals and AV block presence.
• Spontaneous AV conduction was analyzed by temporarily inhibiting PM function.

Main Results:

• Follow-up in 95 patients after prophylactic PM showed high-degree AV block in 25% (24/95) over 45 months.
• Risk of AV block increased with first-degree AV block or Wenckebach point ≤ 100 bpm (HR 3.5).
• Microvoltage on ECG reduced AV block risk (HR 0.2).

Conclusions:

• Prophylactic PM implantation in FAP patients with conduction disorders prevented major cardiac events in 25% over a mean 45-month follow-up.
• Prophylactic PM implantation is suggested to prevent symptomatic bradycardia in these patients.