Prevalence of wild type ATTR assessed as myocardial uptake in bone scan in the elderly population

Myocardial uptake of bone tracers has emerged as useful tool for the early detection of transthyretin amyloidosis (ATTR). The prevalence of wild-type ATTR (ATTRwt) in individuals remains to be established.

All whole body bone scans performed in individuals ≥ 75 years with no previous clinical suspicion of ATTR were revised in a population-based university hospital over a 7-year period (1509 studies corresponding to 1114 patients; 80.5 ± 4.1 years, 65% males). Positive cardiac uptake was defined according to Perugini score as grade 2 or 3. Heart failure (HF) hospitalizations during the follow-up were obtained from regional administrative databases.

Thirty-one patients ≥ 75 years (2.78%) showed cardiac uptake; compared with those without uptake, these patients were older (85 ± 5 vs. 80 ± 4, p < 0.001) and predominantly males (90% vs. 64%, p = 0.005). The prevalence of cardiac uptake was 3.88% in males and 0.77% in females, and increased with age, reaching 13.9% in males≥85 years (2.7% among females). The estimated prevalence for the European standard population ≥ 75 years was 4.15% in males, 1.03% in females and 2.59% in the general population. HF hospitalizations rates were 14% in patients without uptake and 29% in those with cardiac uptake (p = 0.034). After adjusting for age and gender, cardiac uptake was associated with a higher risk of HF hospitalization (OR 2.60, 95%CI 1.09-5.74, p = 0.022).

Myocardial uptake in bone scan is very prevalent with ageing, mainly affects males and is associated with an increased risk of HF hospitalization. These findings reinforce ATTRwt as a relevant cause of HF in the elderly.