Functional correlates of N-terminal natriuretic peptide type B (NT-proBNP) response to therapy in cardiac light chain (AL) amyloidosis

In cardiac (light chain) AL amyloidosis, a decrease in circulating free light chains (FLCs) higher than 50% is associated with reduced N-terminal natriuretic peptide type B (NT-proBNP) serum concentration, improvement of heart failure symptoms, and prolonged survival. To assess the functional correlates of these changes, echocardiographic indices of systolic and diastolic regional function were compared at diagnosis and after response achievement in 32 patients. FLCs and NT-proBNP were concomitantly measured. No significant change in left ventricular wall thicknesses, chamber dimensions, indices of diastolic dysfunction or ejection fraction was observed after chemotherapy. In contrast, systolic longitudinal excursion of both the interventricular septum and the lateral wall was increased (from 5.2 +1.4 to 6.8 +1.5 and from 6.2 +1.3 to 7.7 +1.4 mm, respectively; p50.05 for both). These changes were significantly correlated with the extent of FLCs (p=0.05) and NT-proBNP (p=0.05) reduction. In cardiac AL amyloidosis, hematological response to chemotherapy and reduction of cardiac biomarkers are associated with improved indices of regional systolic function.