Effect of sodium nitroprusside on the occurrence of atrial fibrillation after cardiothoracic surgery.

BACKGROUND

Postoperative atrial fibrillation (POAF) is a frequent complication following cardiothoracic surgery and is associated with an increase in morbidity, mortality, and cost. One small prospective study of patients undergoing isolated coronary artery bypass graft surgery has demonstrated a decrease in the risk of POAF with the use of sodium nitroprusside.

OBJECTIVE

To determine whether there is an association between intraoperative sodium nitroprusside use and the incidence of POAF.

METHODS

A retrospective cohort of 1025 patients aged 18 years and older who underwent any cardiac surgery between April 2007 and July 2010 was evaluated at Regional Hospital of Scranton. Patients with a history of atrial fibrillation, those who had undergone cardiothoracic surgery, or those undergoing surgical treatment for atrial fibrillation were excluded. The primary outcome was the odds of developing POAF given the utilization of sodium nitroprusside during cardiothoracic surgery. POAF was defined according to the Society of Thoracic Surgeons Adult Cardiac Surgery Database version 2.61 as a new onset of atrial fibrillation/flutter requiring treatment that was not present preoperatively. Data on use of intraoperative sodium nitroprusside were obtained from the pharmacy department's billing database.

RESULTS

The final analysis included 699 patients; 473 received sodium nitroprusside. The incidence of POAF was 25.4% in the sodium nitroprusside group and 27.9% in the control group. Univariate analysis demonstrated no association of sodium nitroprusside with POAF (OR 0.880; 95% CI 0.615 to 1.257). Multivariate analysis also showed no significant difference in the odds of POAF with sodium nitroprusside (OR 0.827; 95% CI 0.565 to 1.210). Repeating the analysis in 276 propensity score-matched patients also failed to demonstrate any association (OR 0.774; 95% CI 0.454 to 1.319).

CONCLUSIONS

There was no significant association between the use of sodium nitroprusside during cardiothoracic surgery and POAF.