Patterns and implications of B-type natriuretic peptide measurement in patients with non-ST-segment elevation acute coronary syndromes.

Elevated B-type natriuretic peptide (BNP) levels are associated with increased risk for mortality in patients with non-ST-segment-elevation (NSTE) acute coronary syndromes (ACS). However, the optimal use of BNP measurement for the risk stratification of these patients remains unclear. This study was conducted to analyze patterns of, and factors associated with, BNP measurement in patients with NSTE ACS from the Can Rapid Risk Stratification of Unstable Angina Patients Suppress Adverse Outcomes With Early Implementation of the American College of Cardiology/American Heart Association Guidelines? (CRUSADE) quality improvement initiative from 2003 through 2006. The association of degree of BNP elevation with in-hospital mortality in patients with measured BNP levels across risk categories was also analyzed. A total of 16,323 of 77,071 patients (21.2%) from 486 hospitals had BNP levels measured; the rate of BNP measurement by quarter increased from 5.1% to 27.7% during this analysis. Factors most strongly associated with BNP measurement included signs of heart failure on presentation, older age, previous heart failure, faster presenting heart rate, and higher body mass index. The adjusted risk for mortality was higher in patients who had BNP levels measured than in those who did not (adjusted odds ratio 1.14, 95% confidence interval 1.03 to 1.25). In patients with BNP levels measured, a higher degree of BNP elevation was associated with incrementally higher in-hospital mortality rates across risk categories. BNP levels were measured in approximately 1/5 of patients with NSTE ACS in contemporary practice. BNP was most frequently measured in patients presenting with high-risk characteristics, but the association of incremental increases in BNP levels with higher mortality rates was similar across risk categories. In conclusion, more widespread measurement of BNP levels for risk stratification of patients with NSTE ACS may be warranted.