Predictors of treatment response and survival outcomes in patients with advanced cardiac AL amyloidosis

Abstract

Patients with advanced cardiac immunoglobulin light chain (AL) amyloidosis have a poor prognosis. Early hematologic and cardiac responses can prolong survival, but predictors of these outcomes have yet to be clarified. We report on 142 patients with newly diagnosed stage IIIb AL amyloidosis. After a median follow-up of 60 months, the median overall survival (OS) was 9 months. Independent baseline factors associated with shorter OS were symptom onset to diagnosis >6 months (hazard ratio [HR], 1.94; P = .003); bone marrow plasmacytosis ≥ 10% (HR, 1.98; P = .01); troponin I > 0.635 ng/mL (HR, 1.62; P = .04); New York Heart Association class III or IV (HR, 1.67; P = .04); and 6-minute walk test distance < 200 m (HR, 1.85; P = .01). Early hematologic (within 1 month) and cardiac (within 3 months) responses were significantly associated with longer survival. In a 1-month landmark analysis, patients with a hematologic very good partial response, partial response, and no response had a median OS of 47, 25, and 5 months, respectively (P < .0001). Patients with cardiac response at 3 months had significantly longer OS (47 vs 11 months; P < .0001). On multivariable modeling, bortezomib use was associated with early hematologic and cardiac responses and longer OS. Symptom onset to diagnosis duration of >6 months and difference between the involved and uninvolved free light chain > 350 mg/L were independently associated with lower odds of an early cardiac response. This study identified factors predictive of treatment outcomes and survival in advanced cardiac AL amyloidosis.