Survival of cardiorespiratory arrest after coronary artery bypass grafting or aortic valve surgery.

Background: Study objectives were to (1) report the clinical profile of and outcome for patients who experience a cardiorespiratory arrest after coronary artery bypass grafting or aortic valve replacement, and (2) identify factors associated with improved probability of survival.
Methods: We identified 108 consecutive patients who had cardiorespiratory arrest after coronary artery bypass grafting or aortic valve replacement between April 1999 and June 2008. We studied the characteristics of arrests and survivors, and performed a multivariate logistic analysis to determine features associated with survival to hospital discharge.
Results: Cardiac arrest (n = 86) was more common than respiratory arrest (n = 13; unknown cause, n = 9). Cardiorespiratory arrest occurred with decreasing frequency from the day of surgery. Ventricular fibrillation or tachycardia was the dominant mechanism of cardiac arrest (70% versus 17% for asystole versus 13% for pulseless electrical activity), and the principal causes were postoperative myocardial infarction (n = 46; 53%) and tamponade or bleeding (n = 21; 24%). Resternotomy was performed in 45 patients (52%), cardiopulmonary bypass reinstituted in 14 (16%), and additional grafts constructed in 5 (6%). The causes of respiratory arrest were mainly pulmonary (n = 8) and neurologic (n = 5). Survival to hospital discharge was better for respiratory arrest (69%) than for cardiac arrest (50%). Older age, ejection fraction less than 0.30, and postoperative myocardial infarction decreased the probability of survival.
Conclusions: Ventricular fibrillation or tachycardia was the most common mechanism, and myocardial infarction, the predominant precipitating cause of cardiac arrest after coronary artery bypass grafting or aortic valve replacement. Despite aggressive resuscitation, outcome is poor. Young patients with good left ventricular function had a better probability of survival if they did not suffer a postoperative myocardial infarction.