Nesiritide and clinically relevant outcomes in cardiac surgery: a meta-analysis of randomized studies

B-type natriuretic peptide is a cardiac hormone that relaxes vascular smooth muscle and causes arterial dilatation. Nesiritide has been associated with increased urine output; reduced diuretic requirements; and suppression of aldosterone, endot-helin, and norepinephrine. We have independently conducted the first systematic review and meta-analysis of randomized trials to determine the impact of nesiritide on renal replacement therapy and death in patients undergoing cardiac surgery. We performed a meta-analysis of 6 randomized controlled studies including 560 patients (280 receiving nesiritide and 280 assigned to the control group). Two unblinded reviewers selected randomized trials studying nesiritide in patients undergoing cardiac surgery. Nesiritide doses ranged from 0.005 mcg/kg/min to 0.01 mcg/kg/min. Nesiritide did not reduce postoperative creatinine peak values: -0.16 [-0.42, 0.10], p for effect=0.23, p for heterogeneity<0.01, I2=90.5%) or the need for renal replacement therapy (1/177 in the nesiritide group vs 4/176 in the control group OR 0.39 [0.07, 2.06], p for effect=0.27, p for heterogeneity=0.70, I2=0%). We observed an interesting trend toward a reduction in mortality in the nesiritide group:13/280 (4.6%) vs 22/280 (7.8%) OR 0.57 [0.28, 1.15], p for effect=0.12, p for heterogeneity=0.43, I2=0%. Nesiritide did not reduce time of mechanical ventilation -8.77 hours [-21.42, 3.88], p=0.17, length of hospital stay -2.67 days [-6.50, 1.16], p=0.17 or intensive care unit (ICU) stay -0.94 days [-2.83, 0.95], p=0.33. In conclusion, further randomized controlled trials are needed to support the hypothesis that nesiritide improves clinically relevant outcomes in cardiac surgery.