Role of brain natriuretic peptide (BNP) in risk stratification of adult syncope

Abstract

Aims: To assess the value of a near-patient brain natriuretic peptide (BNP) test to predict medium term (3 month) serious outcome for adult syncope patients presenting to a UK emergency department (ED). Methods: This was a prospective cohort pilot study. Consecutive patients aged >16 years presenting with syncope over a 3 month period were eligible for prospective enrolment. All patients who were medium or high risk according to our ED's existing syncope guidelines underwent near-patient BNP testing using the Triage point of care machine. Results: 99 patients were recruited. 72 of 82 high and medium risk patients underwent BNP measurement. 11 patients had a serious outcome, 9 of whom had BNP measured. In 25 (35%) patients, BNP was >100 pg/ml, and in 3 of these it was .1000 pg/ml. 6 of the 25 patients (24%) with a BNP .100 pg/ml, and all 3 patients with a BNP .1000 pg/ml, were in the serious outcome group. BNP was raised over 100 pg/ml in 6 of the 9 serious outcome patients having a BNP measured (66%), and over 1000 pg/ml in 3 (33%). Conclusions: This early work suggests that BNP may have a role in the risk assessment of syncope patients in the ED. Further work is required to see how BNP interacts with other clinical variables. Near-patient BNP testing may be shown to be an independent predictor of adverse outcome either alone or incorporated into existing syncope clinical decision rules and scores in order to improve their sensitivity and specificity. Further studies are required to evaluate this.

Clinical predictors of cardiac syncope at initial evaluation in patients referred urgently to a general hospital: the EGSYS score

“…In a recent study, assessment of NT-pro-BNP was helpful in differentiating cardiac from non-cardiac syncope 24. In another study, BNP testing showed it to be an independent predictor of adverse outcome in patients with syncope presenting to an ED 25. Further studies are required to define the role of biomarkers in the diagnostic algorithm of syncope in order to improve their sensitivity and specificity.…”

Diagnostic and prognostic utility of troponin estimation in patients presenting with syncope: a prospective cohort study

“…Based on an earlier pilot study of 100 patients,16 17 we assumed that the study population would have a raised troponin I rate of 10% and that serious outcome or all-cause death would occur in 50% of troponin I-positive patients and 15% of troponin I-negative patients. We calculated that, to detect a difference in outcome with troponin I measurement, we would need 185 patients with 17 serious outcomes or all-cause deaths to have 80% power at p<0.05.…”

Changes to the cardiac biomarkers of non-elite athletes completing the 2009 London Marathon

“…Although BNP was originally used to determine severity and prognosis in heart failure, the development of rapid and inexpensive assays has allowed its role to evolve and expand. It is increasingly being used in the acute setting to differentiate between cardiac and non-cardiac causes of dyspnoea20 and it has been suggested to also play a role in identifying cardiac causes of syncope 21. Studies investigating BNP in the context of endurance events are fewer but do suggest a rise after prolonged exercise 6 8–11 13…”