2D Echocardiographic Findings, NT-ProBNP Levels, and Outcomes in Dyspnoeic Patients: Results from the Pro-BNP Investigation of Dyspnoea in the Emergency Department- a Single Centre Experience

Background: Dyspnoeic in the emergency department with multiple co-morbidities is a diagnostic challenge. Approximately 15-20% of acute dyspneic in the Emergency Department due to ADHF (acute decompensated heart failure) are misdiagnosed. B-type peptide (BNP) and its amino-terminal fragment (NT-proBNP) accurately identify HF in dyspnoeic patients. In the general population with dyspnoea, plasma pro-BNP concentrations are increased in left ventricular dilatation, hypertrophy, systolic dysfunction, or diastolic dysfunction but are unaffected by pulmonary dysfunction.

Aims and Objectives: To study the relation between NT pro-BNP & echocardiographic findings in acute dyspnoeic patients, and the relation between NT pro-BNP and In-hospital Mortality.

Materials and Methods: Source of data- Patients admitted to the Emergency Room or cardiac intensive care unit with a history of acute dyspnea in a tertiary cardiac care center in south India, meeting inclusion & exclusion criteria, were studied.

Results: The study population is predominantly constituted of the elderly population. The most common co-morbid condition was hypertension. The present study uses an NT pro BNP level of 900pg/ml as the cut-off level. 78 patients were positive for the test. Echocardiography showed that 58% had LV systolic dysfunction, 60% had diastolic dysfunction. 42 patients had EF >55%, 10 patients between 55-45%, 33 patients between 44-30% and 15 patients had EF < 30%. Mortality rate was 6% in the whole study population. However, Mortality was seen in only NT pro-BNP positive group it was not statistically significant (p=0.46).

Conclusions: NT pro-BNP correlates well with the worsening of LV systolic function; as the EF decreases, NT pro-BNP increases. Increase in NT pro-BNP levels has to be interpreted in the clinical context, and it is not a substitute for echocardiography for assessing cardiac abnormalities and dysfunction.