Investigations

B-natriuetic peptide ^{a b}

Why?

B-natriuretic peptide can help diagnose and exclude heart failure

Patient	Target Disorder and Reference Standard	Diagnostic Test	LR+ (95% CI)	Post-test Probability
suspected heart failure a   (pre-test probability: 63%)	LV ejection fraction < 50% (echocardiography)	B-natriuetic peptide: 75 pg/ml or higher	32 (12 to 83)	98%
		49-74 pg/ml	0.43 (0.29 to 0.65)	43%
		< 49 pg/ml	0.029 (0.012 to 0.070)	5%