Incidence and Predictors of New-Onset Silent Atrial Fibrillation after Coronary Artery Bypass Graft Surgery.

AIMS: We investigated the incidence, risk factors, and prognostic impact of silent atrial fibrillation (AF) after coronary artery bypass graft (CABG) surgery. METHODS: This observational study prospectively included 100 patients referred for CABG surgery. Holter ECG monitoring was used to record every arrhythmic event for 7 days. AF was defined as at least one episode >30 s. Episodes recorded on Holter ECG monitoring but not clinically identified were classified as silent AF. RESULTS: Among 34 patients who developed new-onset AF, 13 had silent AF. Compared with patients with maintained sinus rhythm (SR), silent AF patients had a significantly higher logistic EuroSCORE (2.9 (1.5-5.2) versus 2.3 (1.4-3.7), p = 0.017) and were more likely to have previous sleep apnea (31% versus 8%, p = 0.016) and left atrial diameter >45 mm (36% versus 5%, p = 0.002). At one-year follow-up, 30% of silent AF patients had developed symptomatic AF versus 7% in the SR group (p = 0.03) and 11% in the clinical AF group (p = 0.21). CONCLUSION: After CABG surgery, silent AF is common and may be associated with a higher incidence of recurrences at one-year follow-up than clinical AF. Improved screening for silent AF may help to reduce thromboembolic events in this high-risk population.

Low preoperative cholesterol level is a risk factor of sepsis and poor clinical outcome in patients undergoing cardiac surgery with cardiopulmonary bypass.

OBJECTIVES: Systemic inflammatory response syndrome and sepsis frequently occur after cardiac surgery with cardiopulmonary bypass. The aim of the present study was to investigate whether preoperative cholesterol levels can predict sepsis onset and postoperative complications in patients undergoing cardiac surgery with cardiopulmonary bypass. DESIGN: Prospective observational study. SETTING: Surgical ICU of a French university hospital. PATIENTS: Two hundred and seventeen consecutive patients older than 18 years admitted for planned cardiac surgery with cardiopulmonary bypass. INTERVENTIONS: Measurements of plasma blood lipids and inflammation markers before anesthesia induction (baseline), at cardiopulmonary bypass start, at cardiopulmonary bypass end, and 3 and 24 hours after cardiac surgery. Outcomes were compared in systemic inflammatory response syndrome patients with sepsis (n = 15), systemic inflammatory response syndrome patients without sepsis (n = 95), and non-systemic inflammatory response syndrome patients (n = 107). MEASUREMENTS AND MAIN RESULTS: A gradual decrease in plasma cholesterol concentration occurred during surgery with cardiopulmonary bypass but was no longer present after correction for hemodilution. Corrected cholesterol levels were significantly lower at baseline in sepsis patients than in other subgroups, and it remained lower in the sepsis group during and after cardiopulmonary bypass. With regard to sepsis, the discriminatory power of baseline cholesterol was fairly good as indicated by receiver operating characteristic curve analysis (area under the curve, 0.78; 95% CI, 0.72-0.84). The frequency of sepsis progressively decreased with increasing baseline cholesterol level quintiles (18.6% and 0% in the bottom and top quintiles, respectively, p = 0.005). In multivariate analysis, baseline cholesterol levels and cardiopulmonary bypass duration were significant and independent determinants of the 3-hour postcardiopulmonary bypass increase in concentrations of procalcitonin and interleukin-8, but not of interleukin-6. CONCLUSIONS: Low cholesterol levels before elective cardiac surgery with cardiopulmonary bypass may be a simple biomarker for the early identification of patients with a high risk of sepsis.