Does sodium nitroprusside decrease the incidence of atrial fibrillation after myocardial revascularization?: a pilot study.

BACKGROUND: Atrial fibrillation (AF) often occurs after coronary artery bypass grafting and can result in increased morbidity and mortality. In the present pilot study, our aim was to investigate whether sodium nitroprusside (SNP), as a nitric oxide donor, can reduce the frequency of post-coronary artery bypass grafting AF. METHODS AND RESULTS: To investigate the effectiveness of SNP in the prophylaxis of AF, we conducted a prospective, randomized, placebo-controlled clinical study on 100 consecutive patients in whom we performed elective and initial CABG operations. A control group of 50 patients were treated with placebo (dextrose 5% in water), whereas the SNP group (n=50 patients) was treated with SNP (0.5 microg x kg(-1) x min(-1)) during the rewarming period. High-sensitivity C-reactive protein levels were measured before surgery and 5 days postoperatively. All patients were monitored postoperatively with telemetry. Baseline characteristics were similar in both treatment groups. AF occurred in 12% of the SNP group and 27% of the control group. The occurrence of AF was significantly lower in the SNP group (P=0.005). The duration of AF in the SNP group was significantly shorter than that in the control group (5.33+/-1.86 and 7.55+/-1.94 hours, respectively; P=0.023). C-reactive protein levels were higher postoperatively in the control group than in the SNP group (P<0.05). Postoperative AF significantly prolonged postoperative hospital stay (P<0.05). CONCLUSIONS: The incidence of postoperative AF in the SNP group was reduced significantly. Further studies are needed to better delineate the anti-AF profile of SNP.

The effect of sodium nitroprusside infusion on renal function during reperfusion period in patients undergoing coronary artery bypass grafting: a prospective randomized clinical trial.

OBJECTIVE: Acute renal failure remains a common and serious complication of cardiac surgery. In this randomized trial, we aimed to assess whether sodium nitroprusside (SNP) infusion during cardiopulmonary bypass (CPB) could prevent renal dysfunction after coronary artery bypass grafting (CABG) surgery. METHODS: Between October 2004 and May 2006, 240 consecutive patients with stable angina undergoing elective CABG for multi-vessel coronary artery disease were prospectively randomized into control (n=116, 72 men, mean age 61.3+/-9.7 years) or SNP groups (n=124, 81 men, 60.8+/-10.8 years). SNP group received SNP after initiation of rewarming period during CPB at a dose of 0.1mg/kg/h and the infusion was concluded by weaning from CPB. The anesthetic and CPB regimes were standardized. Blood urea nitrogen (BUN), serum creatinine (SCr), estimated glomerular filtration rate (eGFR), creatinine clearance (C(Cr)), urine output, serum cardiac specific troponin I (cTnI), creatine kinase cardiac isoenzyme (CKMB), and CPK were measured preoperatively and daily until day 5 after surgery. RESULTS: There were no differences in baseline levels of BUN, SCr, eGFR, C(Cr), cTnI, CKMB, CPK levels and EuroSCORES between the groups. Although the durations of cross clamp, CPB times, and postoperative cardiac enzymes were similar in both groups; in the control group, there was a significantly lower urine excretion during CPB (p=0.002) and the operation (p=0.041). Peak postoperative SCr levels were significantly (p=0.001) lower in the SNP group than in the control group (1.29+/-0.28 vs 1.42+/-0.34mg/dl). The incidence of >or=50%DeltaSCr was significantly higher in the control group when compared with the SNP group (35.3 vs 13.7%, p<0.001). Development of new C(Cr) less than 50ml/min postoperatively was significantly higher in the control group compared with the SNP group (14 vs 38%, p<0.001). CONCLUSION: SNP administration during rewarming period of non-pulsatile CPB in patients undergoing CABG surgery is associated with improved renal function compared with conventional medical treatment providing adequate preload and mean arterial pressures.