Introduction: In the heart failure population, overweight individuals are associated with lower mortality, termed the obesity survival paradox. The influence of body mass index (BMI) on outcomes in cardiac amyloidosis has not been characterized. We sought to determine the association between BMI and mortality, and hematologic and cardiac response in patients with light chain (AL) amyloidosis.

Methods: We conducted a retrospective study of patients with cardiac AL amyloidosis referred between 1/1/2009 and 09/30/2018. We collected baseline demographics including BMI and recorded mortality and hematologic and cardiac response. Cox proportional hazards model and logistic regression models were constructed to examine the association between BMI and outcomes.

Results: Of the 78 patients, 17 patients had a BMI of 17-22.5, 19 a BMI of 22.6-25, 23 a BMI of 25.1-29.9, and 19 a BMI of ≥ 30 kg/ m2. The median follow-up was 51 months. There was no relationship between BMI as a continuous variable and mortality (adjusted HR 0.98, 95% CI 0.91-1.05, p=0.54). While there was no relationship between high BMI (≥ 25 kg/m2) and hematologic response (adjusted OR 0.97, 0.34-2.76, p=0.96), there was a relationship between high BMI and a lower likelihood of achieving cardiac response (adjusted OR 0.23, 0.07-0.71, p=0.011).

Conclusions: In this cohort of patients with AL cardiac amyloidosis, there was no significant relationship between BMI and mortality. Patients with a higher BMI were significantly less likely to achieve a cardiac response. These findings highlight the importance of a multidisciplinary approach involving oncologists, cardiologists, and nutritionists in the treatment of this very complex multi-organ disease.

AL amyloidosis, BMI, Mortality, Hematologic response, Cardiac response