Background: Cardiac amyloidosis (CA) is a progressive infiltrative cardiomyopathy that leads to severe heart failure and, once clinically relevant, poses a high mortality risk. There are two leading pathogenetic causes of CA; light chains (due to hematological diseases) or transthyretin (ATTR) associated. Epidemiological data for CA are still sparse and heterogeneous, but urgently needed since novel therapies against ATTR-CA are now available, and diagnostic and therapeutic pathways have to be refined.

Aim: We aimed to assess prevalence rates of cardiac amyloidosis among cardiac and non-cardiac patients undergoing routine echocardiography in an echo lab of a large university clinic serving all medical specialities in central Germany.

Methods: We established a retro- and prospective database based on suspicious findings in echocardiography for all echocardiographic exams over an 8.5 year period (03/2013 and 09/2021). During this time, 41,375 patients underwent at least one echo exam at our echo lab of a maximum care university hospital. Indication for echo examinations were mixed, and consisted of non-cardiac and cardiac patients with acute and chronic illnesses as well as screening exams (e.g. before major surgery or chemotherapy), also in healthy persons (e.g. diagnostic for syncope). Patients with suspicious echocardiography were retrospectively analysed whether they underwent further diagnostic or if it remained an unproven suspicion (Figure 1). All echos of suspicious cases were comprehensively re-analysed regarding novel surrogate parameters and indices for CA.  Various clinical and laboratory parameters were collected.

Results: The mean age of the cohort of 41,375 patients was 65.1±15.8 years for the first or only echo examination with a slightly unbalanced gender distribution (45% female). The age distribution is shown in the table.  While 128 patients were suspected, in 16 the diagnosis was falsified and in 47 the diagnosis was proven (light chain n=16, ATTR n= 31; Figure). A substantial proportion of patients with suspicious echo received no further diagnostic work-up (N = 65). Over the given time frame of 101 months, the prevalence of suspicious echocardiograms was 1 per 323 patients (or 31 per 10,000).  The proven cases had a prevalence of 1 per 880 patients (or 11.3 per 10,000). Since ATTR-CA is a disease of the elderly, we saw a vanishingly small number of cases in persons younger than 70 years (Table), whereas 90% of all CA-patients were older than 70 years when the first suspicion for CA was voiced. At timing of diagnosis, AL-CA patients were almost 10 years younger compared to diagnosis of ATTR-CA (69.1±8.4 years vs. 77.4±8.5 years). In patients older than 80 years, the prevalence rate of ATTR-CA peaked with 22.6 cases per 10.000 patients (0.23 %). Also, the prevalence rate of ATTR-CA is roughly twice as high compared to AL-CA.

Conclusion: Here, we provide for the first time an estimation of prevalence rates for CA for a defined volume of echocardiograms in an all-comers population. Our data show, that in a mixed population of a hospital of maximum care prevalence rate of CA is much higher than expected. Echo labs need to build an awareness for this “rare” disease since it can prompt suspicion for CA, also in clinically silent or so far unrecognized CA cases.