Diagnostic cut-off levels of plasma brain natriuretic peptide to distinguish left ventricular failure in emergency setting.

Abstract

To determine the diagnostic cut-off values of brain natriuretic (BNP) peptide to establish left ventricular failure in patients presenting with dyspnoea in emergency department. Descriptive study. Ziauddin University Hospital, Karachi, from July to December 2011. BNP estimation was done on Axysm analyzer with kit provided by Abbott diagnostics, while the Doppler echocardiography was done on Toshiba istyle (UICW-660A) using 2.5 MHz and 5.0 MHz probes. Log transformation was done to normalize the original BNP values. A receiver operating curve was plotted to determine the diagnostic cut-off value of BNP which can be used to distinguish CHF from other causes of dyspnoea. Statistical analysis was performed by SPSS version 17. A total of 92 patients presenting with dyspnoea in the emergency department were studied. There were 38/92 (41.3%) males and 54/92 (58.7%) females, and the average age of the study population was 64 ± 14.1 years. These patients had BNP levels and Doppler echocardiography done. The average BNP was found to be 1117.78 ± 1445.74 pg/ml. In log transformation, the average was found to be 2.72 ± 0.58. BNP value of 531 pg/ml was found to be the cut off to distinguish between cardiogenic and non-cardiogenic causes of dyspnoea. BNP value of 531 pg/ml can distinguish CHF from other conditions as a cause of dyspnoea in emergency.