Prevalence of transthyretin cardiac amyloidosis in patients with aortic stenosis

Background: Transthyretin cardiac amyloidosis (ATTRCA) is a prevalent disease, and it can be associated with heart failure (HF), left ventricle hypertrophy (LVH), atrial fibrillation (AF), and aortic stenosis (AS).

Aim: The study aims to detect the prevalence of ATTRCA in the symptomatic AS population.

Method: A single-center prospective study screening for ATTRCA in patients diagnosed with symptomatic severe AS undergoing aortic valve (AV) intervention.

Results: A total of 27 patients were enrolled, of which 15 (56%) were men. The mean age was 72.8 ± 10.5 years. HF symptoms were present in 11 (40.7%) patients at New York Heart Association (NYHA) class II, while 15 (55.6%) patients had NYHA class III symptoms. AF was present in 6 (22.2%) patients. The mean left ventricle ejection fraction (LVEF) was 49.4 ± 9.75%, and the mean stroke volume (SV) was 37.4 ± 8.7 ml/m². The interventricular septal thickness (IVS) was 1.2 ± 0.18 cm. The AS mean gradient was 46 ± 12 mmHg, and the aortic valve area (AVA) was 0.69 ± 0.16 cm². The ATTRCA was diagnosed by bone scintigraphy in 5 (18.5%) AS patients. Perugini scores of 2 and 3 were considered positive for ATTRCA with the heart/contralateral lung (H/CL) ratio of 1.48 ± 0.35. There was no difference in LVEF between patients with ATTRCA and those without ATTRCA 50 ± 9.8% vs 47 ± 9.3%; p-value 0.55. The ATTRCA had a lower SV of 33.9 ± 6.9 ml/m² compared to patients without ATTRCA 37.5 ± 8.8 ml/m²; p-value of 0.34. There was no significant difference in LVH or IVS thickness between the patients with ATTRCA and those without ATTRCA. The left ventricle (LV) mass index in ATTRCA was 87 ± 21 g/m² compared to patients without ATTRCA 98.7 ± 26 g/m², with a p-value 0.38, and the IVS thickness was 1.1 ± 0.22 cm compared to patients without ATTRCA 1.2 ± 0.18 cm; p-value 0.17. The left atrial (LA) volumes were significantly higher in the ATTRCA group 55.5 ± 25.6 ml/m² compared to patients without ATTRCA 37.5 ± 10.9 ml/m² with a significant p-value 0.028. The mean AV gradient was lower in ATTRCA patients at 40.8 ± 8.4 mmHg, compared to patients without ATTRCA at 46.1 ± 12.1 mmHg; it did not reach a statistical significance p-value 0.3. There was a significant difference in LV relative longitudinal strain (LS) between patients with ATTRCA 11.8 ± 3.2 and those without ATTRCA 63.3 ± 22.6 with a significant p-value 0.001.

Conclusion: ATTRCA is prevalent in AS patients; bone scintigraphy is recommended for screening AS patients for ATTRCA.