Resuscitative Value of B-Type Natriuretic Peptide in Comatose Survivors Treated With Hypothermia After Out-of-Hospital Cardiac Arrest due to Cardiac Causes

Abstract

Background Two randomized studies have shown a neurological benefit of therapeutic hypothermia in comatose survivors after out-of-hospital cardiac arrest, but there are no studies of the cardiac neurohormone of B-type natriuretic peptide (BNP) in patients treated with hypothermia. Methods and Results A prospective study was conducted of 109 comatose patients who were treated with mild hypothermia after out-of-hospital sudden cardiac arrest due to cardiac causes and whose BNP level was measured on arrival at the emergency room. The primary endpoint was a favorable neurological outcome at the time of hospital discharge. A total of 45 of the 109 patients had a favorable neurological outcome. The unadjusted rate of a favorable neurological outcome decreased in a stepwise fashion among patients in increasing quartiles of BNP level (p<0.001) and this association remained significant in subgroups of patients. The BNP cutoff value of 80 pg/ml for a favorable neurological outcome had an accuracy of 87.2%. In the multiple logistic-regression analysis, a BNP level of 80 pg/ml or less was an independent predictor of favorable neurological outcome. Conclusions The measurement of BNP was found to provide valuable information regarding the neurological outcome of comatose survivors treated with mild hypothermia after out-of-hospital cardiac arrest due to cardiac causes. (Circ J 2007; 71: 370 - 376)