Atrial fibrillation/flutter (AF) was prevalent in more than half of patients with transthyretin cardiac amyloidosis (ATTR-CA) and was associated with wild-type amyloid transthyretin (ATTRwt), higher Columbia score and increased left atrial volume index (LAVI), according to a study published Dec. 29 in JACC: Advances. Additionally, around half of the ATTR-CA patients without baseline AF developed it within two years, as predicted by the Columbia score, and both hereditary amyloid transthyretin (ATTRv) and tafamidis therapy were protective against this incident AF.

The retrospective cohort study by Nicholas Chan, MD, MS; Matthew S. Maurer, MD, FACC, et al., tracked 419 patients with ATTR-CA with AF (mean age 78 years; 12% women; 84% White, 3% Hispanic; 13% with ATTRv) or without AF (mean age 74 years; 15% women; 69% White, 8% Hispanic; 40% with ATTRv) from 2001 to 2021.

Results showed AF present in 58% (n=244) of the population at baseline, associated with both higher Columbia Score (odds ratio [OR], 1.48) and higher LAVI (OR, 1.05) and lower prevalence of ATTRv (OR, 0.19; all p<0.05).

At two years, an additional 71 patients (41%) developed AF. Notably, a higher Columbia score (hazard ratio, 1.18; p=0.035) was a predictor of new-onset AF while the CHARGE-AF score and LAVI were not. ATTRv and tafamidis therapy were associated with a 56% reduction (p=0.017) and 46% reduction (p=0.034) in incident AF, respectively.

"Prior imaging studies have demonstrated tafamidis delays structural and functional changes in the heart, as reflected by lesser deterioration of biventricular ejection fraction and global longitudinal strain, LA reservoir strain, left ventricular mass index, and extracellular volume," write the authors on the finding. "These effects may in part mediate the observation that tafamidis use is associated with lower incidence of atrial fibrillation."