Diagnostic and Prognostic Utility of Cardiovascular Magnetic Resonance Imaging in Light-Chain Cardiac Amyloidosis

Abstract

Although the presence of abnormal late gadolinium enhancement (LGE) in cardiac amyloidosis has been well established, its prognostic implication and utility to identify cardiac involvement in patients with systemic amyloidosis is unknown. The aim of this study was to assess the diagnostic and prognostic significance of cardiovascular magnetic resonance imaging in patients with amyloid light-chain amyloidosis but unknown cardiac involvement. Cardiovascular magnetic resonance imaging with LGE was performed in 28 patients with systemic amyloidosis. The presence of cardiac amyloidosis was determined by separate clinical evaluation. The performance of LGE for the prediction of cardiac amyloidosis and prognostic implications of LGE were determined. LGE was observed in 19 patients (68%). The sensitivity, specificity, positive predictive value, and negative predictive value of LGE for the identification of clinical cardiac involvement were 86%, 86%, 95%, and 67%, respectively. During a median follow-up period of 29 months, there were 5 deaths (82% survival). LGE itself did not predict survival (p = 0.62). LGE volume was positively correlated with serum level of B-type natriuretic peptide (BNP; R = 0.64, p < or =0.001), and in multivariate analysis, LGE volume proved the strongest independent predictor of BNP. BNP was correlated with New York Heart Association class (p = 0.03). Reduced right ventricular end-diastolic volume (p <0.01) and stroke volume (p = 0.02) were associated with mortality. In conclusion, in patients with systemic amyloidosis, LGE is highly sensitive and specific for the identification of cardiac involvement but does not predict survival. LGE is strongly correlated with heart failure severity as assessed by BNP.