Experience With Long-term Inotrope Therapy In Advanced Cardiac Amyloidosis Management

Background

Patients with symptomatic cardiac amyloidosis (CA) have limited therapeutic options with many being ineligible for left ventricular assist devices or heart transplants. Tafamidis has limited efficacy in reversing advanced refractory CA. While long term continuous intravenous inotrope infusion therapy (LTInoT) might improve quality of life in individuals with advanced heart failure, its utility in symptomatic, refractory heart failure due to cardiac amyloidosis remains unknown. We describe our experience with LTInoT in patients with cardiac amyloidosis and refractory heart failure.

Methods

We conducted a retrospective review of consecutively enrolled patients with cardiac amyloidosis on LTInoT from 2019-2023, cumulatively for 9031 person-days of follow-up (∼301 person-months).

Results

17 patients (12 male) were included. Participants were predominantly White (n=11) with a mean age of 79±8 years. 10 participants had HFrEF and 13 had ATTR. Chronic kidney disease, hyperlipidemia, and atrial fibrillation were comorbid in 13(76%), 12(71%), and 12(71%) patients, respectively. The mean left ventricular EF was 32±14%. LTInoT comprised milrinone (n=10) and dobutamine (n=7). Concurrent medications included a mineralocorticoid receptor antagonist (n=11, 65%), Tafamidis (n=9, 53%), and sodium-glucose co-transporter inhibitor (n=7, 41%). Cardiovascular hospitalizations (Median [quartile 1-3]) decreased while receiving LTInoT relative to a year prior (2[1-3] vs 3[2-4], p=0.03). All-cause hospitalizations were similar (3[2-4]). 6 (35%) patients died within a year of LInoT (Table). The median duration after which mortality occurred was 6 months (Q1-Q3: 3-16 months).

Conclusion

LTInoT has potential to reduce cardiovascular hospitalizations in advanced heart failure due to cardiac amyloidosis. Further investigation is needed to identify suitable candidates for LInoT.