Objective: To determine the performance of a new NT-proBNP assay in co mpariso n with brain natriuretic peptide (BNP)-in identifying left ventricular systolic dysfunction (LVSD) in randomly selected community populati...Objective: To determine the performance of a new NT-proBNP assay in co mpariso n with brain natriuretic peptide (BNP)-in identifying left ventricular systolic dysfunction (LVSD) in randomly selected community populations. Methods: Blood s amples were taken prospectively in the community from 591 randomly sampled indiv iduals over the age of 45 years, stratified for age and socioeconomic status and divided into four cohorts (general population; clinically diagnosed heart failu re; patients on diuretics; and patients deemed at high risk of heart failure). D efinite heart failure (left ventricular ejection fraction (LVEF)< 40%) was iden tified in 33 people. Samples were handled as though in routine clinical practice . The laboratories undertaking the assays were blinded. Results: Using NT-proBN P to diagnose LVEF< 40%in the general population, a level of >40 pmol/l had 80 %sensitivity, 73%specificity, 5%positive predictive value (PPV), 100%negativ e predictive value (NPV), and an area under the receiver-operator characteristi c curve (AUC) of 76%(95%confidence interval (CI) 46%to 100%). For BNP to dia gnose LVSD, a cut off level of >33 pmol/l had 80%sensitivity, 88%specificity, 10%PPV, 100%NPV, and AUC of 88%(95%CI 75%to 100%). Similar NPVs were found for patients randomly screened from the three other populations. Conclusions: B oth NT-proBNP and BNP have value in diagnosing LVSD in a community setting, wit h similar sensitivities and specificities. Using a high cut off for positivity w ill confirm the diagnosis of LVSD but will miss cases. At lower cut off values, positive results will require cardiac imaging to confirm LVSD.展开更多
文摘Objective: To determine the performance of a new NT-proBNP assay in co mpariso n with brain natriuretic peptide (BNP)-in identifying left ventricular systolic dysfunction (LVSD) in randomly selected community populations. Methods: Blood s amples were taken prospectively in the community from 591 randomly sampled indiv iduals over the age of 45 years, stratified for age and socioeconomic status and divided into four cohorts (general population; clinically diagnosed heart failu re; patients on diuretics; and patients deemed at high risk of heart failure). D efinite heart failure (left ventricular ejection fraction (LVEF)< 40%) was iden tified in 33 people. Samples were handled as though in routine clinical practice . The laboratories undertaking the assays were blinded. Results: Using NT-proBN P to diagnose LVEF< 40%in the general population, a level of >40 pmol/l had 80 %sensitivity, 73%specificity, 5%positive predictive value (PPV), 100%negativ e predictive value (NPV), and an area under the receiver-operator characteristi c curve (AUC) of 76%(95%confidence interval (CI) 46%to 100%). For BNP to dia gnose LVSD, a cut off level of >33 pmol/l had 80%sensitivity, 88%specificity, 10%PPV, 100%NPV, and AUC of 88%(95%CI 75%to 100%). Similar NPVs were found for patients randomly screened from the three other populations. Conclusions: B oth NT-proBNP and BNP have value in diagnosing LVSD in a community setting, wit h similar sensitivities and specificities. Using a high cut off for positivity w ill confirm the diagnosis of LVSD but will miss cases. At lower cut off values, positive results will require cardiac imaging to confirm LVSD.
