Clinical manifestations and cardiac abnormalities in systemic Amyloid A Amyloidosis

Cardiac involvement in systemic amyloid A (AA) amyloidosis is traditionally considered rare. Respectively, contemporary data describing cardiac characteristics of patients with systemic AA amyloidosis are scarce.

All patients with a diagnosis of systemic amyloidosis were identified from electronic medical records of a tertiary medical center. Patients with non-AA amyloidosis, concomitant multiple myeloma, lack of histological confirmation, or absence of cardiac evaluation were excluded. Probable cardiac involvement was diagnosed based on predefined criteria.

The final cohort included 43 patients with AA amyloidosis, diagnosed either by immunohistochemistry (n = 32,74%) or clinically (positive Congo Red staining + systemic inflammatory disease). The mean age was 56 ± 11 years, and 23 (54%) were women. Probable cardiac involvement was identified in14 (33%) patients. Patients with probable cardiac involvement had wider QRS duration (101 milliseconds, IQR (83,114) vs 86 milliseconds, IQR (76,98), p-value = 0.019), right ventricular hypertrophy (29% vs 0, p-value = 0.008) and dysfunction (21% vs 0, p-value = 0.029), larger left atrial diameter (41.6 ± 5.7 mm vs 38 ± 4.6, p-value = 0.04), and more frequent pericardial effusion (43% vs 14%, p-value = 0.009) compared with those without probable cardiac disease. Patients with probable cardiac involvement had higher median serum Amyloid A levels (24 mg/L IQR (15,56) vs 13 mg/L (6.6,36), p-value = 0.047) and more frequently had evidence of gastrointestinal manifestations (64% vs 28%, p-value = 0.021), then those without cardiac involvement.

Pathological cardiac findings are not uncommon in patients with AA amyloidosis warranting a routine cardiac evaluation and longitudinal follow up.