Atrial Fibrillation in the Elderly: The Role of Sub-Clinical Isolated Cardiac Amyloidosis

Darshan Krishnappa,Ilknur Can,Richard Dykoski,Mackenzie Mbai,Jian-Ming Li,Inder S. Anand,Venkatakrishna N. Tholakanahalli,Viorel Florea,Y. S. Chandrashekar

doi:10.1038/s41598-019-53119-z

Abstract

Amyloid infiltration of the atrium is described in patients with valvular heart disease and is associated with an increased risk for atrial fibrillation(AF) while amyloid deposits in the ventricles is increasingly being diagnosed in patients with HFpEF. The role of amyloid deposits in patients with AF without valvular heart disease, which represents the most common form of AF globally, is undefined. In this study, we sought to assess the prevalence of sub-clinical isolated cardiac amyloidosis (ICA) at autopsy and the odds of AF in these patients. A total of 1083 patients were included in the study and 3.1% of patients were found to have asymptomatic ICA. Patients with ICA were older and had a higher odds of AF independent of age and CHA2DS2VASc score. Amongst patients with AF, those with ICA were more likely to have persistent forms of AF and had a lower sinus rhythm P-wave amplitude. Further studies are required to further define this entity, identify imaging modalities to aid in antemortem diagnosis of ICA and to establish the optimal management strategies in these patients.

Highlights

Atrial fibrillation (AF) is the most common cardiac arrhythmia, and is associated with considerable morbidity and mortality[1]
Seven patients had a clinical diagnosis of plasma cell dyscrasias or systemic amyloidosis, while 2 patients had evidence of multiorgan amyloid infiltration at autopsy and were excluded
Autopsy consisted of examination of a single organ in 180 patients who were excluded from the study

Summary

Introduction

Atrial fibrillation (AF) is the most common cardiac arrhythmia, and is associated with considerable morbidity and mortality[1]. A considerable proportion of elderly patients with heart failure with preserved ejection fraction (HFpEF) have been found to have isolated amyloid deposits in the heart[8,9]. A proportion of patients with valvular heart disease have been found to have clinically undetected amyloid deposits on atrial biopsies obtained during cardiac surgery and such deposits have been shown to be associated with an increased risk of AF10,11. The role of such clinically undetected atrial amyloid deposits in the aetiopathogenesis of AF occurring in the absence of valvular heart disease has not been previously evaluated. We sought to assess the prevalence of AF in patients with clinically undetected isolated cardiac amyloidosis (ICA) detected at autopsy and identify electrocardiographic (EKG) markers of such amyloid deposits

Methods

Results

Discussion

Conclusion