Despite the development of innovative therapies, patients with immunoglobulin light chain (AL) amyloidosis and stage IIIb cardiac involvement have a poor prognosis. However, higher survival results from a quick hematologic reaction.
In 249 patients with newly discovered stage IIIb cardiac AL amyloidosis, researchers assessed the effect of the depth and timing of the early cardiac response on the prognosis. Intent to treat evaluations of hematologic and cardiac responses were performed. 219 individuals (84%) died after a median follow-up of 52 months, and the median survival time was 4.2 months.
The rates of hematologic response at 30 and 90 days were 22% (at least very good partial response [VGPR] in 9%) and 24% (at least VGPR in 15%), respectively. A quicker hematologic response improved survival. At 90 days, 21 (8%) patients achieved a cardiac response (cardiac very good partial response [cardiac VGPR] in 12 cases and cardiac partial response [cardiac PR] in 9). Longer survival (median, 54 months) was seen at the 90-day landmark analysis for patients who had demonstrated cardiac response (median, 62 vs. 26 months, P =.011). Patients who had cardiac VGPR had a higher median survival than those who had cardiac PR (92 vs. 24 months; P =.027), but patients who had no cardiac response had a poorer median survival (median, 6 months). Negative predictors of the 90-day cardiac response included a baseline difference of involved/uninvolved free light chains > 50 mg/L (odds ratio [OR], 0.21, P=.024) and a bone marrow plasma cell infiltration > 10% (OR, 0.23, P=.040). In stage IIIb AL amyloidosis, early cardiac responses were uncommon but feasible and associated with prolonged longevity.