Atrial fibrillation in transthyretin amyloidotic cardiomyopathy: prevalence and echocardiographic predictors.

Background: Conduction disorders and arrhythmias frequently accompany cardiac amyloidosis (CA), with atrial fibrillation (AF) being the most prevalent manifestation. The prevalence of AF varies across different types of CA, with transthyretin (TTR) type showing the highest prevalence upon diagnosis.

Methods: A retrospective, observational analysis was conducted to evaluate the prevalence of AF and to identify echocardiographic predictors related to the development of AF in our population of patients with transthyretin cardiac amyloidosis (TTR-CA).

Results: A total of 99 patients with TTR-CA were identified, with a median age of 82 (75-85) years, a median ejection fraction of 50% (43-60) and 97 of them wild type. At the time of cardiomyopathy diagnosis, 55% had AF, and during follow-up, 43% developed new AF. Among the latter group, there was a non-significant tendency to have a smaller diastolic diameter, lower left ventricular ejection fraction, increased septal thickness, higher pulmonary pressure, and lower tissue velocities, with statistical significance only found in the right ventricular S wave velocity: 8.5 cm/s (7.7-9) vs. 9.7 cm/s (8.4-10) (P=0.046).

Conclusions: The high prevalence and incidence of AF in TTR-CA is demonstrated in our series. Doppler echocardiography might help to identify patients with signs of more advanced cardiomyopathy, such as lower right ventricle tissue velocity, who might be at higher risk of developing AF and gain the benefit of prompt diagnosis and treatment.