Atrial electrofunctional predictors of incident atrial fibrillation in cardiac amyloidosis.

Atrial fibrillation (AF) is common in patients with cardiac amyloidosis (CA) and is a significant risk factor for heart failure hospitalization and thromboembolic events. This study was designed to investigate the atrial electrofunctional predictors of incident AF in CA. A multicenter, observational study was conducted in 4 CA referral centers including sinus rhythm patients with light-chain (AL) and transthyretin (ATTR) CA undergoing electrocardiography and cardiac magnetic resonance imaging. The primary end point was new-onset AF occurrence. Overall, 96 patients (AL-CA, n = 40; ATTR-CA, n = 56) were enrolled. During an 18-month median follow-up (Q1–Q3, 7–29 months), 30 patients (29%) had incident AF. Compared with those without AF, patients with AF were older (79 vs 73 years; P =.001). They more frequently had ATTR (87% vs 45%; P <.001); electrocardiographic interatrial block (IAB), either partial (47% vs 21%; P =.011) or advanced (17% vs 3%; P =.017); and lower left atrial ejection fraction (LAEF; 29% vs 41%; P =.004). Age (hazard ratio [HR], 1.059; 95% CI, 1.002–1.118; P =.042), any type of IAB (HR, 2.211; 95% CI, 1.03–4.75; P =.041), and LAEF (HR, 0.967; 95% CI, 0.936–0.998; P =.044) emerged as independent predictors of incident AF. Patients exhibiting any type of IAB, LAEF <40%, and age >78 years showed a cumulative incidence for AF of 40% at 12 months. This risk was significantly higher than that carried by 1 (8.5%) or none (7.6%) of these 3 risk factors. In patients with CA, older age, IAB on 12-lead electrocardiography, and reduced LAEF on cardiac magnetic resonance imaging are significant and independent predictors of incident AF. A closer screening for AF is advisable in CA patients carrying these features. [Display omitted] [ABSTRACT FROM AUTHOR]