The Risk Factors And Survival Analysis Of Cardiac Light Chain Amyloidosis

Objective To identify independent risk factors and predictors of survival in patients with cardiac light chain amyloidosis.Methods This study included 26 patients with cardiac AL amyloidosis who werediagnosed by biopsy and Serum,urine immunoglobulin electrophoresis and Cardiac magnetic resonance imaging(CMRI)in Jiangsu Province People’s Hospital between October 2009 and January 2016.Clinical manifestations included an assessment of HF severity based on the New York Heart Association(NYHA)functional classification,heart rate and blood pressure;N-terminal pro b-type natriuretic peptide(NT-proBNP)and D-dimer;and Glomerular Filtration Rate(eGFR)estimated using the CKD-EPI(Chronic Kidney Disease Epidemiology Collaboration)equation.Laboratory data included quantitative estimations of muscle hemoglobin and cardiac troponin T(cTnT).All the patients were followedup until August 26,2016.Baseline clinical data including clinical symptoms,laboratory data,and echocardiographic findings were recorded.Statistical analyses were performed using STATA 12.0.Survival time was calculated from the point of diagnosis until death or the last follow-up.Univariate and multivariate Cox proportional hazard regression analyses were performed to estimate hazard ratios(HRs).The Kaplan-Meier method and log-rank test were used to compare survival times.All tests were two-sided.Statistical significance was considered when P<0.05.Results In univariate analyses,NT-proBNP(P=0.022)and D-dimer(P=0.002)were independent risk factors for cardiac AL amyloidosis.In multivariable analysis,NT-proBNP and D-dimer were also independent risk factors for cardiac AL amyloidosis(both p=0.002).The cut-off value of NT-proBNP for 6-month all-cause-mortalitywas 4509.5 ng/L(sensitivity 73.3%,specificity 77.8%,area under curve(AUC)67%,95%confidence interval(CI)0.442-0.899).The cut-off value of D-dimer for 6-month all-cause-mortality was 1.22 mg/L(sensitivity 60%,specificity 90%,AUC 70%,95%CI 0.489-0.911).All patients were stratified according to NT-proBNP or D-dimer level:Group 1:patients with NT-proBNP≤4509.5ng/L and D-dimer ≤1.22 mg/L;Group 2:patients with NT-proBNP ≤4509.5ng/L and D-dimer>1.22 mg/L;Group 3:patients with NT-proBNP>4509.5ng/L and D-dimer≤1.22 mg/L;Group 4:patients with NT-proBNP>4509.5ng/L and D-dimer>1.22 mg/L.Patients with NT-proBNP or D-dimer levels above the cut-off value had a higher all-cause-mortality rate compared,to patients below the cut-off value.Conclusion D-dimer and NT-proBNP were independent risk factors for cardiac AL amyloidosis,D-dimer may be an important biomarker of prognosis in cardiac AL amyloidosis patients.