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Study Objective: We want to know whether a low B-type natriuretic peptide (BNP) level, obtained shortly after presentation and independent of information provided by other clinical findings and laboratory tests, would affect management decisions for emergency department (ED) patients with nondiagnostic troponin levels. Previous studies have generally been retrospective or inclusive of patients with heart failure., Methods: We prospectively studied patients evaluated for possible acute coronary syndromes who had nondiagnostic levels of serum troponin, nondiagnostic ECGs, and no clinical heart failure within 4 hours of presentation. BNP levels were obtained but results not provided to clinical staff. The primary outcome was the composite of acute myocardial infarction or death within 30 days. The secondary outcome was the composite of the primary outcome, percutaneous coronary intervention, or coronary artery bypass grafting., Results: Almost half of the patients screened for but excluded from the study had known heart failure or a history of heart failure. The resulting cohort was composed of 348 patients, with a median age of 64 years and 51% women. The primary outcome occurred in 16.1% of patients; the secondary outcome, in 27.6%. At a standard cutoff of BNP greater than or equal to 80 pg/mL, the negative predictive value for the primary outcome was 80% (95% confidence interval 73% to 86%). The negative predictive value for the secondary outcome was 69% (95% confidence interval 61% to 75%). Multivariable analyses supported these findings., Conclusion: A single, low BNP level obtained shortly after presentation to the ED could not identify patients at low risk for 30-day acute myocardial infarction or death., (Copyright © 2010 American College of Emergency Physicians. Published by Mosby, Inc. All rights reserved.)

Objective: Radial artery harvesting for coronary artery bypass may lead to digit ischemia if collateral hand circulation is inadequate. The modified Allen's test is the most common preoperative screening test used. Unfortunately, this test has high false-positive and false-negative rates. The purpose of this study was to compare the results of a modified Allen's test with digit pressure change during radial artery compression for assessing collateral circulation before radial artery harvest., Methods: One hundred twenty-nine consecutive patients were studied before coronary artery bypass operations. A modified Allen's test was performed with Doppler ultrasound to assess blood flow in the superficial palmar arch before and during radial artery compression. A decreased audible Doppler signal after radial artery compression was considered a positive modified Allen's test. First and second digit pressures were measured before and during radial artery compression. A decrease in digit pressure of 40 mm Hg or more (digit DeltaP) with radial artery compression was considered positive., Results: Seven of 14 dominant extremities (50%) and 8 of the 16 nondominant extremities (50%) with a positive modified Allen's test had a digit DeltaP of less than 40 mm Hg (false positive). Sixteen of 115 dominant extremities (14%) and 5 of 112 nondominant extremities (4%) with a negative Allen's test had a digit DeltaP of 40 mm Hg or more with radial artery compression (false negative)., Conclusion: Use of the modified Allen's test for screening before radial artery harvest may unnecessarily exclude some patients from use of this conduit and may also place a number of patients at risk for digit ischemia from such harvest. Direct digit pressure measurement is a simple, objective method that may more precisely select patients for radial artery harvest. Additional studies are needed to define objective digital pressure criteria that will accurately predict patients at risk for hand ischemia after radial harvest.