Malnutrition at Diagnosis Predicts Mortality in Patients With Systemic Immunoglobulin Light‐Chain Amyloidosis Independently of Cardiac Stage and Response to Treatment

Background: Nutrition status was shown to be a prognostic factor in patients with immunoglobulin light‐chain amyloidosis (AL). However, malnutrition was associated with cardiac involvement, thus suggesting potential interactions. This study aim was to clarify the association among nutrition status, cardiac stage, and mortality in AL. Methods: One hundred twenty‐eight consecutive newly diagnosed, treatment‐naïve patients with histologically confirmed AL were enrolled. Anthropometric, biochemical, and clinical variables were assessed. Results: At multivariable Cox proportional hazard analysis, body mass index (BMI) < 22 kg/m² (HR = 1.98, 95% CI = 1.09–3.56) and unintentional 6‐month weight loss (WL) ≥ 10% (HR = 1.94, 95% CI = 1.00–3.74) resulted in independent predictors of survival after controlling for hematologic response to treatment (HR = 0.27, 95% CI = 0.14–0.53) and cardiac stage (Mayo Clinic stage III, HR = 4.42, 95% CI = 2.61–7.51). There was no effect modification of malnutrition on mortality by cardiac stage (P for interaction = .27). Moderate and severe malnutrition (prevalence: 21.9% and 7.8%, respectively) similarly increased the risk of death (HR = 3.09, 95% CI = 1.75–5.46; 2.88, 95% CI = 1.23–6.72, respectively). Conclusions: In AL, malnutrition at diagnosis is a frequent comorbidity that affects the prognosis independently of hematologic response to treatment and cardiac stage. Nutrition status should be systematically considered in future intervention trials in AL. Nutrition support trials are warranted.