Table 4.

Predictive values of optimal threshold concentrations^* of brain natriuretic peptide and N-terminal atrial natriuretic peptide for identifying left ventricular systolic dysfunction

Patient group	Brain natriuretic peptide				N-terminal atrial natriuretic peptide
	Optimal threshold (pg/ml}	Positive predictive value (95% CI)	Negative predictive value (95% CI)		Optimal threshold (ng/ml)	Positive predictive value (95% CI)	Negative predictive value (95% CI)
Moderate or severe left ventricular dysfunction	46	0.69 (0.44 to 0.94)	0.55 (0.42 to 0.68)		4.4	0.52 (0.32 to 0.72)	0.51 (0.36 to 0.66)
Severe left ventricular dysfunction	32	0.35 (0.12 to 0.58)	0.92 (0.81 to 1.03)		1.4	0.22 (0.8 to 0.36)	1.00
Fractional shortening <25%	46	0.56 (0.24 to 0.88)	0.86 (0.74 to 0.98)		5.4	0.31 (0.08 to 0.54)	0.82 (0.68 to 0.96)

^*Optimal indicates the peptide concentration giving the best combination of sensitivity and specificity.