Sensitivity and Specificity of B-Type Natriuretic Peptide in Diagnosing Heart Failure in Pregnancy

Abstract

To evaluate the performance of B-type natriuretic peptide as a diagnostic tool for heart failure in pregnant or postpartum women with singleton gestations. We conducted a retrospective study of diagnostic accuracy. We identified pregnant and postpartum women with B-type natriuretic peptide and echocardiography performed at an obstetric teaching hospital from 2007 to 2018. Women with known cardiac disease or multiple gestation were excluded. A panel of two cardiovascular disease experts, blinded to B-type natriuretic peptide values, determined the diagnosis of heart failure by consensus. Their judgement was based on detailed clinical features and parameters at the time of presentation with suspected heart failure. Where consensus could not be reached, differences were adjudicated by a third expert. A receiver operating characteristic curve estimated the sensitivity, specificity, positive likelihood ratio, and negative likelihood ratio of B-type natriuretic peptide at various thresholds. In total, 22 pregnant and 38 postpartum women were included in the cohort. Average age was 32±6.8 years. The most common clinical features at the time of presentation with suspected heart failure included preeclampsia (33/60, 55%), dyspnea (50/60, 83%), chest discomfort (34/60, 58%), and bilateral lower extremity edema (32/60, 53%). In total, 39 (65%) women had heart failure. The median B-type natriuretic peptide level was 326 pg/mL (interquartile range 200.5-390.5) in women with heart failure, as compared with 75.5 pg/mL (interquartile range 19-245) in women without heart failure (P<.01). The estimated optimal B-type natriuretic peptide cutoff was 111 (95% CI 78-291) pg/mL. Using this threshold, 45 (75%) women had an elevated B-type natriuretic peptide, which yielded a 95% sensitivity (95% CI 83-99), 62% specificity (95% CI 38-82), a positive likelihood ratio of 2.5 (95% CI 1.4-4.3), and a negative likelihood ratio of 0.1 (95% CI 0.0-0.3) for heart failure. B-type natriuretic peptide is a useful clinical tool to evaluate pregnant and postpartum women with suspected heart failure.