Prevalence of cardiac amyloidosis among elderly patients with recent-onset atrial fibrillation. The PREVAL-ATTR study.

Background: Transthyretin cardiac amyloidosis (ATTR-CA) is increasingly recognized as a treatable form of heart failure. Atrial fibrillation (AF) is common in patients with ATTR-CA. Whether recent-onset AF can be used as an early marker to identify patients with ATTR-CA has not been elucidated.

Methods: This was a prospective study conducted at 3 Spanish centers. ATTR-CA noninvasive screening was offered to patients ≥65 years old recently diagnosed (<1 year) with non-valvular AF and who had ≥1 echocardiographic, electrocardiographic or clinical sign suggestive of ATTR-CA.

Results: A total of 121 patients were included (75% male, mean age 77±7 years). Ten patients (8.3%, 95%CI:4-14.7%), were diagnosed with cardiac amyloidosis (CA): 5 with definite wild-type ATTR-CA (ATTRwt), 4 with likely ATTRwt and one with undetermined CA. Compared to patients without CA, patients with CA were older (84±4 vs. 76±7 years;p<0.001), more frequently men (90% vs. 59%; p=0.047), presented higher median NTproBNP (3800 pg/L, IQR:1682-6101 vs. 1048 pg/mL, IQR:427-3154;p=0.017) and higher left ventricular hypertrophy (LVH) (14 mm, IQR:13-17 vs. 12 mm, IQR:12-13;p=0.003). Patients with CA also showed higher rate of permanent AF (90% vs. 49.5%;p=0.018) and a greater need for pacemaker implantation during follow-up (30% vs. 7.3%;p=0.049). No differences in mortality were observed between patients with and without CA after a median follow-up of 13 months (IQR:11-16 months).

Conclusions: Routine DPD scanning in elderly patients with recent-onset AF, LVH and an additional red flag may help to identify patients with ATTR-CA. However, larger studies evaluating this strategy in more diverse clinical settings would be required.