Cardiac Complications in Pregnancy: A Systematic Review and Meta-Analysis of Diagnostic Accuracy of BNP and N-Terminal Pro-BNP

Introduction: Serum brain-type natriuretic peptide (BNP) levels may be involved in detecting the breakdown of defense mechanisms in pregnant women. BNP and N-terminal pro-BNP (NT-proBNP) levels can be used in emergency settings as a biomarker to rule out or confirm cardiac complications. The present study was conducted as an attempt to evaluate the performance of BNP and NT-proBNP as diagnostic tools for cardiac complications, including heart failure and pre-eclampsia, in pregnant and recently-delivered women.

Methods: This meta-analysis was performed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. To extract the data, articles meeting the inclusion criteria were directly reviewed by two of the authors. Disputes were resolved through discussion with all authors before data mining. In cases of unresolved disagreement, a third reviewer was consulted to achieve consensus. A quantitative analysis of the total bias of publications was performed using Stata software version 14.0, using funnel plots and Deek's test.

Results: Overall, 13 unique studies were included in this review. The pooled sensitivity, specificity and positive and negative predictive values for diagnosing cardiac complications in pregnant women when BNP level was ≤ 100 ng/L, were determined to be 95, 62, 71 and 91%, respectively. The corresponding measures when the BNP levels were 100-500 ng/L were calculated to be 98, 92, 97 and 92%, respectively. The pooled sensitivity, specificity and positive and negative predictive values for diagnosing cardiac complications in pregnant women using NT-proBNP were 78, 74, 20.5 and 97%, respectively.

Conclusion: Our results suggest that both BNP and NT-proBNP levels can be used as diagnostic tools among pregnant and newly-delivered women to diagnose cardiac complications, including heart failure and pre-eclampsia. While BNP showed a relatively better diagnostic accuracy compared to NT-proBNP, it must be noted that the number of studies evaluating NT-proBNP included in this meta-analysis was low and the studies were inconsistent in terms of cutoff value. Further studies are required to confirm the prospective use of BNP and NT-pro BNP in assessing common symptoms that indicate cardiac complications during labor. Moreover, the clinical use of the NT-proBNP test in this field requires further study.