Background

Amyloidosis is a multi-systemic disease resulting from deposition of misfolded proteins as insoluble fibrils in the interstitium of affected organs including the heart, subsequently leading to organ failure. Cardiac involvement is predominantly observed in light chain (AL) amyloidosis and wild-type transthyretin (ATTRwt) amyloidosis. With the present analysis we sought to investigate the impact of co-incident amyloidosis on the outcome of patients hospitalized due to heart failure (HF) irrespective of the underlying HF-etiology.

Methods

We analyzed data of patients hospitalized due to HF, or myocarditis with HF as well as patients undergoing heart transplantation in co-prevalence with HF of the German nationwide inpatient sample (2005-2018). HF patients were stratified for presence of amyloidosis. HF patients with and without amyloidosis were compared and impact of amyloidosis on outcomes was computed (source: RDC of the Federal Statistical Office and the Statistical Offices of the federal states, DRG Statistics 2005-2018, and own calculations).

Results

The present analysis comprises 5,478,835 patients hospitalized due to HF in Germany between 2005 and 2018. Amyloidosis was prevalent in 5,407 patients (0.1%). Patients with amyloidosis were younger at the time of hospitalization compared with patients without amyloidosis (75.0 (67.0/80.0) vs. 79.0 (72.0-85.0); p<0.001), had a higher prevalence of cancer (14.8% vs. 3.6%; p<0.001) and were predominantly male (68.9%). Although patients without amyloidosis had a pronounced cardiovascular risk profile with higher prevalence of arterial hypertension (45.4% vs. 35.6%; p<0.001), diabetes mellitus (38.9% vs. 18.5%; p<0.001) and obesity (11% vs. 3.8%; p<0.001) and concomitant coronary artery disease (40.5% vs. 34.5%; p<0.001), adverse events during hospitalization were more often documented in HF patients with amyloidosis. HF patients with amyloidosis were more often diagnosed with acute renal failure (12.8% vs. 6.3%; p<0.001), shock (3.3% vs. 1.3%; p<0.001) and bleeding complications requiring transfusion of blood constituents (7.1% vs. 5.4%; p<0.001) and necessitated more often cardio-pulmonary resuscitation (2.7% vs. 1.4%; p<0.001). Additionally, we observed a trend towards a higher in-hospital mortality in patients with amyloidosis (10.1% vs. 9.3%; p=0.053). With respect to treatments, patients with amyloidosis required more often pacemaker implantations (0.9% vs. 0.6%; p=0.032), cardiac resynchronization therapy (0.3% vs. 0.1%; p<0.001) and heart transplantation (1.2% vs. 0.1%; p<0.001). In multivariate logistic regression analysis (adjusting for age, sex, cancer, coronary artery disease, chronic obstructive pulmonary disease, hypertension, kidney disease, diabetes mellitus, atrial fibrillation, hyperlipidaemia), amyloidosis was independently associated with acute renal failure (OR 1.40 [95%CI 1.28-1.52], p<0.001), shock (OR 1.65 [95%CI 1.42-1.92], p<0.001), cardio-pulmonary resuscitation (OR 1.58 [95%CI 1.34-1.86], p<0.001) and intracerebral bleeding (OR 3.13 [95%CI 1.68-5.83], p<0.001) during hospitalization.

Conclusions

Amyloidosis impresses as an independent risk factor for severe complications during hospitalization in patients with HF. Health care providers should be aware of this issue especially with respect to the requirements of treatment options and monitoring of these HF patients.