Epidemiology, mechanisms, and risks - American College of Chest Physicians guidelines for the prevention and management of postoperative atrial fibrillation after cardiac surgery
ABSTRACT Atrial fibrillation (AF) is one of the most frequent complications of cardiac surgery, affecting more than one third of patients. The mechanism of this arrhythmia is believed to be reentry. The electrophysiologic substrate may be preexisting or may develop due to heterogeneity of refractoriness after surgery. Multiple perioperative factors have been proposed to contribute to the latter, including operative trauma, inflammation, elevations in atrial pressure (including that due to left ventricular diastolic dysfunction), autonomic nervous system imbalance, metabolic and electrolyte imbalances, or myocardial ischemic damage incurred during the operation. Whether ectopic beats originating in the pulmonary veins explain at least some episodes of postoperative AF, as has been shown for nonsurgical patients with the arrhythmia, is of current interest as such sites could easily be isolated at the time of surgery. The development of postoperative AF is associated with a higher risk of operative morbidity, prolonged hospitalization, and increased hospital cost compared with that in patients remaining in sinus rhythm. Many factors have been identified as being associated with postoperative AF, but the most consistent variable across studies is increasing patient age. It is speculated that age-related pathologic changes in the atrium contribute to arrhythmia susceptibility. An important modifiable risk factor for postoperative AF is the failure to resume therapy with beta-adrenergic receptor blockers after surgery. The stratification of patients who are at higher risk for AF would focus preventative strategies on patients who are most likely to benefit from such therapy. Nonetheless, since postoperative AF often develops in patients with comorbidities who are predisposed to other complications and prolonged hospitalization, it is presently unclear whether the prevention of postoperative AF will result in improved patient outcomes, particularly shorter hospitalizations.
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ABSTRACT: Introduction. The onset of atrial fibrillation (AF) after open-heart surgical interventions is related to systemic and local inflammatory process. This is associated with the increases in the levels of inflammatory markers. Due to the anti-inflammatory properties of statins, statin therapy seems to be effective in the prevention of AF after coronary artery bypass grafting (CABG). However, other studies failed to demonstrate any antiarrhythmic effect of statins. Objective. To assess the role of statin therapy in the primary and secondary prevention of AF after GABG. Material and methods. A retrospective analysis of 225 medical records from the register of GABG interventions in 2013 was performed. The cases selected were divided in two groups. The first group included those patients who received no statin therapy and the second group included those patients who did receive statin therapy for at least three days prior to the operation and for all days postoperatively. A postoperative AF event was defined as an AF episode occurring in the first 6 days after surgery and lasting for more than 5 minutes. Results. The first group included 93 (41%) patients and the second group 132 (59%) patients. The rate of AF was 29% in Group 1 and 9% in Group 2 (p=0.0001). On Day 4 after surgery, leucocytes count was 10.9 (9; 13) in the first group and 9.1 (7,6; 10) in the second group (р=0.000002). On Day 1, leucocytes count was also lower in the second group but the difference was insignificant [9.5 (7.4; 12) vs 10.4 (7.5; 12.3), р=0.39]. AF paroxysms occurred earlier in the first group than in the second group [Day 2 (2; 3) vs Day 3 (3; 4.5), р=0.039]. An analysis of leucocytes count day-to-day changes was performed in a subgroup of patients who developed AF postoperatively. The analysis showed that peak leucocytes concentrations occurred on the day of onset of arrhythmia. In this subgroup, leucocytes count increased from 10.4 (7.5; 12.3) on Day 1 after surgery to 10.9 (9; 13) on Day 4 after surgery and to 12.3 (10; 14) on the day of onset of AF (р=0.0083; p<0.016 after application of the Bonferroni correction). The risk of occurrence of postoperative AF was eval- uated using the Cox model of regression. «Prior AF» and «Statin use» were found to be statistically meaningful (р=0.002 and р=0.001, respectively; χ2=38.42, p<0.001). In accordance with the Cox model of regression, the risk of AF was 3.68 for «Prior AF» and 0.31 for «Statin use». Conclusion. In this study, statin therapy prior to and after GABG was found to be an effective method of prevention of AF in the early postoperative period. An anti-inflammatory property demonstrated by statins is one of the factors which may explain their antiarrhythmic effect.
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ABSTRACT: Previous meta-analyses suggest that pre-procedural use of statin therapy may reduce atrial fibrillation (AF) following invasive cardiac interventions (coronary artery by-pass grafting and percutaneous coronary intervention). However, the current evidence on the benefit of statins unrelated to invasive cardiac interventions has not been clarified systematically.International Journal of Cardiology 08/2013; 167(3):624-630. DOI:10.1016/j.ijcard.2012.08.056 · 6.18 Impact Factor
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ABSTRACT: Statin pretreatment in patients undergoing cardiac surgery is understood to prevent postoperative atrial fibrillation (AF). However, this is based on observational and limited randomized trial evidence, resulting in uncertainty about any genuine anti-arrhythmic benefits of these agents in this setting. We therefore aimed to quantify precisely the association between statin pretreatment and postoperative AF among patients undergoing cardiac surgery. A detailed search of MEDLINE and PubMed databases (1st January 1996 to 31st July 2012) was conducted, followed by a review of the reference lists of published studies and correspondence with trial investigators to obtain individual-participant data for meta-analysis. Evidence was combined across prospective, randomized clinical trials that compared the risk of postoperative AF among individuals randomized to statin pretreatment or placebo/control medication before elective cardiac surgery. Postoperative AF was defined as episodes of AF lasting ≥5 min. Overall, 1105 participants from 11 trials were included; of them, 552 received statin therapy preoperatively. Postoperative AF occurred in 19% of these participants when compared with 36% of those not treated with statins (odds ratio 0.41, 95% confidence interval 0.31-0.54, P < 0.00001, using a random-effects model). Atrial fibrillation prevention by statin pretreatment was consistent across different subgroups. Short-term statin pretreatment may reduce the risk of postoperative AF among patients undergoing cardiac surgery. Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2015. For permissions please email: email@example.com.