Postoperative atrial fibrillation (POAF) is the most common complication after coronary artery bypass grafting (CABG). The preventive effect of magnesium on POAF is not well known. This meta-analysis was undertaken to assess the efficacy of intravenous magnesium on the prevention of POAF after CABG.
Eligible studies were identified from electronic databases (Medline, Embase, and the Cochrane Library). The primary outcome measure was the incidence of POAF. The meta-analysis was performed with the fixed-effect model or random-effect model according to heterogeneity.
Seven double-blind, placebo-controlled, randomized clinical trials met the inclusion criteria including 1,028 participants. The pooled results showed that intravenous magnesium reduced the incidence of POAF by 36% (RR 0.64; 95% confidence interval (CI) 0.50-0.83; P = 0.001; with no heterogeneity between trials (heterogeneity P = 0.8, I2 = 0%)).
This meta-analysis indicates that intravenous magnesium significantly reduces the incidence of POAF after CABG. This finding encourages the use of intravenous magnesium as an alternative to prevent POAF after CABG. But more high quality randomized clinical trials are still need to confirm the safety.
Postoperative atrial fibrillation (POAF) is one of the most common complications after cardiac surgery. Patients who develop POAF have a prolonged stay in the intensive care unit and hospital and an increased risk of postoperative stroke. Many guidelines for the management of cardiac surgery patients, therefore, recommend perioperative administration of beta-blockers to prevent and treat POAF. Landiolol is an ultra-short acting beta-blocker, and some randomized controlled trials of landiolol administration for the prevention of POAF have been conducted in Japan. This meta-analysis evaluated the effectiveness of landiolol administration for the prevention of POAF after cardiac surgery.
The Medline/PubMed and BioMed Central databases were searched for randomized controlled trials comparing cardiac surgery patients who received perioperative landiolol with a control group (saline administration, no drug administration, or other treatment). Two independent reviewers selected the studies for inclusion. Data regarding POAF and safety outcomes were extracted. Odds ratios (ORs) with 95% confidence intervals (CIs) were calculated using the Mantel–Haenszel method (fixed effects model).
Six trials with a total of 560 patients were included in the meta-analysis. Landiolol administration significantly reduced the incidence of POAF after cardiac surgery (OR 0.26, 95% CI 0.17–0.40). The effectiveness of landiolol administration was similar in three groups: all patients who underwent coronary artery bypass grafting (CABG) (OR 0.27, 95% CI 0.17–0.43), patients who underwent CABG compared with a control group who received saline or nothing (OR 0.28, 95% CI 0.17–0.45), and all patients who underwent cardiac surgery compared with a control group who received saline or nothing (OR 0.27, 95% CI 0.17–0.42). Only two adverse events associated with landiolol administration were observed (2/302, 0.7%): hypotension in one patient and asthma in one patient.
Landiolol administration reduces the incidence of POAF after cardiac surgery and is well tolerated.
Electronic supplementary material
The online version of this article (doi:10.1007/s12325-014-0116-x) contains supplementary material, which is available to authorized users.
Atrial fibrillation; Beta-blocker; Cardiac surgery; Cardiology; Landiolol; Meta-analysis; Perioperative
Postoperative atrial fibrillation (POAF) has been reported to be associated with reduced long-term survival after isolated coronary artery bypass grafting surgery. The objective of this study was to determine the impact of POAF on long-term survival after valvular surgery.
The authors retrospectively analysed the preoperative and operative data of 2986 consecutive patients with no preoperative history of atrial fibrillation undergoing first valvular surgery (aortic-valve replacement (AVR), mitral valve replacement or mitral valve repair (MVR/MVRp) with or without coronary artery bypass grafting surgery) in their institution between 1995 and 2008 (median follow-up 5.31 years, range 0.1–15.0). The authors investigated the impact of POAF on survival using multivariable Cox regression.
Patients with POAF were older, and were more likely to have hypertension or renal failure when compared with patients without POAF. The 12-year survival in patients with POAF was 45.7±2.8% versus 61.4±2.1% in patients without POAF (p<0.001). On a multivariable analysis, when adjusting for age and other potential confounding factors, POAF tended to be associated with lower long-term survival (HR for all-cause death (HR)=1.17, 95% CI 1.00 to 1.38, p=0.051). The authors also analysed this association separately in patients with AVR and those with MVR/MVRp. In the multivariable analysis, POAF was a significant predictor of higher long-term mortality in patients with AVR (HR=1.22, CI 1.02 to 1.45, p=0.03) but not in patients with MVR/MVRp (HR=0.87, CI 0.58 to 1.29, p=0.48).
POAF is significantly associated with long-term mortality following AVR but not after MVR/MVRp. The underlying factors involved in the pathogenesis of POAF after MVR/MVRp may partially account for the lack of association between POAF and survival in these patients.
To investigate if postoperative atrial fibrillation (POAF) may affect long-term survival following heart-valve surgery.
POAF is significantly associated with long-term mortality following aortic-valve replacement (AVR).
POAF is not associated with long-term mortality following mitral valve replacement/repair.
Strengths and limitations of this study
This study indicates that POAF is a significant predictor of long-term survival after AVR.
Hence, additional specific intervention, possibly a closer follow-up, should be considered in these patients.
This is an observational study, hence causality between POAF and long-term survival following AVR cannot be ascertained.
Postoperative atrial fibrillation (POAF) is the most common complication following cardiac surgery. A variety of POAF risk factors has been reported, but study results have been inconsistent or contradictory, particularly in patients with preexisting atrial fibrillation. The incidence of POAF was evaluated in a group of 10,390 cardiac surgery patients among a comprehensive range of risk factors to identify reliable predictors of POAF.
This 20-year retrospective study examined the relationship between POAF and demographic factors, preoperative health conditions and medications, operative procedures, and postoperative complications. Multivariate logistic regression models were used to evaluate potential predictors of POAF.
Increasing age, mitral valve surgery (OR=1.91), left ventricular aneurysm repair (OR=1.57), aortic valve surgery (OR=1.52), race (Caucasian) (OR=1.51), use of cardioplegia (OR=1.36), use of an intra-aortic balloon pump (OR=1.28), previous congestive heart failure (OR=1.28), and hypertension (OR=1.15) were significantly associated with POAF. The nonlinear relationship between age and POAF revealed the acceleration of POAF risk in patients 55 or older. In patients undergoing coronary artery bypass grafting, increasing age and previous congestive heart failure were the only factors associated with a higher risk of POAF. There was no trend in incidence of POAF over time. No protective factors against POAF were detected, including commonly prescribed categories of medications.
The persistence of the problem of POAF, and the modest predictability using common risk factors, suggest that limited progress has been made in understanding its etiology and treatment.
The objective of this study was to identify and evaluate predictors of postoperative atrial fibrillation (POAF) in a large coronary artery bypass grafting (CABG) cohort. This was a single centre study of 7115 consecutive patients with preoperative sinus rhythm who underwent isolated CABG between January 1996 and December 2009. Independent risk factors for POAF were identified with multiple logistic regression. The predictive quality of the final model was evaluated by comparing predicted and observed events of POAF, in an effort to find patients at high risk of developing POAF. After CABG, 2270 patients (32%) developed POAF during hospital stay. Independent risk factors of POAF included advancing age (odds ratio, OR 2.0–7.3), preoperative S-creatinine ≥150 µmol/l (OR 1.6), male gender (OR 1.2), New York Heart Association class III/IV (OR, 1.2), smoking (OR 1.1), prior myocardial infarction (OR 1.1) and absence of hyperlipidemia (OR 0.9). The final prediction model was moderate (area under curve, 0.62; 95% confidence interval, 0.61–0.64). Patients with POAF had more postoperative complications, including a higher incidence of stroke and increased length of hospital stay. In conclusion, several risk factors for POAF were identified, but the moderate value of the prediction model confirms the difficulty of identifying patients at high risk of developing POAF after CABG.
Postoperative atrial fibrillation; Coronary artery bypass grafting; Ageing
Atrial fibrillation is the most common type of arrhythmia after cardiac surgery. An increasing body of evidence demonstrates that oxidative stress plays a pivotal role in the pathophysiology of atrial fibrillation. N-acetylcysteine (NAC) is a free radical scavenger, and may attenuate this pathophysiologic response and reduce the incidence of postoperative AF (POAF). However, it is unclear whether NAC could effectively prevent POAF. Therefore, this meta-analysis aims to assess the efficacy of NAC supplementation on the prevention of POAF.
Medline and Embase were systematically reviewed for studies published up to November 2011, in which NAC was compared with controls for adult patients undergoing cardiac surgery. Outcome measures comprised the incidence of POAF and hospital length of stay (LOS). The meta-analysis was performed with the fixed-effect model or random-effect model according to the heterogeneity.
Eight randomized trials incorporating 578 patients provided the best evidence and were included in this meta-analysis. NAC supplementation significantly reduced the incidence of POAF (OR 0.62, 95% CI 0.41 to 0.93; P = 0.021) compared with controls, but had no effect on LOS (WMD -0.07, 95% CI -0.42 to 0.28; P = 0.703).
The prophylactic NAC supplementation may effectively reduce the incidence of POAF. However, the overall quality of current studies is poor and further research should focus on adequately powered randomized controlled trials with POAF incidence as a primary outcome measure.
Postoperative atrial fibrillation (POAF) remains the most common complication after cardiac surgery. Current guidelines recommend β-blockers to prevent POAF. Carvedilol is a non-selective β-adrenergic blocker with anti-inflammatory, antioxidant, and multiple cationic channel blocking properties. These unique properties of carvedilol have generated interest in its use as a prophylaxis for POAF.
To investigate the efficacy of carvedilol in preventing POAF.
PubMed from the inception to September 2013 was searched for studies assessing the effect of carvedilol on POAF occurrence. Pooled relative risk (RR) with 95% confidence interval (CI) was calculated using random- or fixed-effect models when appropriate. Six comparative trials (three randomized controlled trials and three nonrandomized controlled trials) including 765 participants met the inclusion criteria.
Carvedilol was associated with a significant reduction in POAF (relative risk [RR] 0.49, 95% confidence interval [CI] 0.37 to 0.64, p<0.001). Subgroup analyses yielded similar results. In a subgroup analysis, carvedilol appeared to be superior to metoprolol for the prevention of POAF (RR 0.51, 95% CI 0.37 to 0.70, p<0.001). No evidence of heterogeneity was observed.
In conclusion, carvedilol may effectively reduce the incidence of POAF in patients undergoing cardiac surgery. It appeared to be superior to metoprolol. A large-scale, well-designed randomized controlled trial is needed to conclusively answer the question regarding the utility of carvedilol in the prevention of POAF.
Atrial fibrillation (AF) is the most common complication of coronary artery bypass graft surgery (CABG). The reported incidence of AF after CABG varies from 20% to 40%. Postoperative AF (POAF) is associated with increased incidence of hemodynamic instability, thromboembolic events, longer hospital stays, and increased health care costs. A variety of pharmacological and nonpharmacological strategies have been employed to prevent AF after CABG. Preoperative and postoperative beta blockers are recommended in all cardiac surgery patients as the first-line medication to prevent POAF. Sotalol and amiodarone are also effective and can be regarded as appropriate alternatives in high-risk patients. Corticosteroids and biatrial pacing may be considered in selected CABG patients but are associated with risk. Magnesium supplementation should be considered in patients with hypomagnesemia. There are no definitive data to support the treatment with nonsteroidal anti-inflammatory drugs, angiotensin-converting enzyme inhibitors, angiotensin receptor blockers, procainamide, and propafenone, or anterior fat pad preservation to reduce POAF.
Atrial fibrillation; Coronary artery bypass; Drug therapy; Cardiac pacing, artificial
Postoperative atrial fibrillation (POAF) is common and associated with poor outcomes. Perioperative ischemia can alter arrhythmic substrate.
To demonstrate an association between perioperative measurement of heart-type fatty acid binding protein (HT-FABP), a sensitive marker of ischemic myocardial injury.
Blood samples from 63 inpatients undergoing coronary artery bypass surgery (CABG), valve surgery or both were obtained before and up to four days after surgery. Continuous telemetry monitoring was used to detect POAF. 59 patients had at least 3 HT-FABP measurements. The relation of ELISA-measured HT-FABP to POAF was assessed using joint logistic regression adjusted for age and surgery type.
Thirty five patients (55%) developed POAF; these were on average older (69.3 ± 10 vs. 60 ± 11 years, p=0.0019), with a higher prevalence of heart failure (43% vs. 17%, p=0.034), chronic obstructive lung disease (26% vs. 4%, p=0.017), preoperative calcium channel blocker use (29% vs. 7%, p=0.031) and more likely to undergo combined surgery (21% vs. 11%, p=0.049). The joint age- and CABG-adjusted model revealed that postoperative but not preoperative HT-FABP levels predicted POAF (coefficient 1.9 ± 0.87, p=0.03). Longer bypass time, prior infarction and worse renal function were all associated with higher postoperative HT-FABP.
A greater rise of HT-FABP is associated with atrial fibrillation after cardiac surgery, suggesting that ischemic myocardial damage is a contributing underlying mechanism. Interventions that decrease perioperative ischemic injury may also decrease the occurrence of POAF.
Atrial Fibrillation; Postoperative; Biomarker; Ischemia; CABG; Valve Surgery
New-onset atrial fibrillation is the most common form of rhythm disturbance following coronary artery bypass grafting surgery (CABG). It is still unclear which factors have a significant impact on its occurrence after this procedure. The aim of this study was to evaluate clinical predictors of postoperative atrial fibrillation (POAF) after myocardial revascularization.
We performed a retrospective analysis of 322 patients who underwent the first CABG operation without baseline atrial fibrillation. All subjects underwent laboratory blood tests, echocardiography and selective coronarography with ventriculography. Patients were continuously electrocardiographically monitored during the first 48–72h after the operation for the occurrence of POAF.
POAF was diagnosed in 72 (22.4%) of the patients. Multivariate logistic regression analysis was used to identify the following independent clinical predictors of POAF: age ≥65 years (OR 1.78; 95%CI: 1.06–2.76; p=0.043), hypertension (OR 1.97; 95%CI: 1.15–3.21; p=0.018), diabetes mellitus (OR 2.09; 95% CI: 1.31–5.33; p=0.010), obesity (OR 1.51; 95%CI: 1.03–3.87; p=0.031), hypercholesterolemia (OR 2.17, 95%CI: 1.05–4.25; p=0.027), leukocytosis (OR 2.32, 95%CI: 1.45–5.24; p=0.037), and left ventricular segmental kinetic disturbances (OR 3.01; 95%CI: 1.65–4.61, p<0.001).
This study demonstrates that advanced age, hypertension, diabetes, obesity, hypercholesterolemia, leukocytosis, and segmental kinetic disturbances of the left ventricle are powerful risk factors for the occurrence of POAF.
atrial fibrillation; cardiac surgery; risk factors
Atrial fibrillation is a common complication after cardiac surgery. The aim of this study is to evaluate whether N-acetylcysteine (NAC) could prevent postoperative atrial fibrillation (POAF).
PubMed, Embase and Cochrane Center Register of Controlled Trials were searched from the date of their inception to 1 July 2013 for relevant randomized controlled trials (RCTs), in which NAC was compared with controls for adult patients undergoing cardiac surgery. Outcome measures comprised the incidence of POAF, all-cause mortality, length of intensive care unit (ICU) stay, hospital length of stay, and the incidence of cerebrovascular events. The meta-analysis was performed with the fixed-effect model or random-effect model according to the heterogeneity.
We retrieved ten studies enrolling a total of 1026 patients. Prophylactic NAC reduced the incidence of POAF (OR 0.56; 95% CI 0.40 to 0.77; P < 0.001) and all-cause mortality (OR 0.40; 95% CI 0.17 to 0.93; P = 0.03) compared with controls, but failed to reduce the stay in ICU and overall stay in hospital. No difference in the incidence of cerebrovascular events was observed.
Prophylactic use of NAC could reduce the incidence of POAF and all-cause mortality in adult patients undergoing cardiac surgery. However, larger RCTs evaluating these and other postoperative complication endpoints are needed.
N-acetylcysteine; Postoperative atrial fibrillation; Cardiac surgery; Meta-analysis
Atrial fibrillation (AF) occurs in 30% patients on the second or third day post operation; therefore, it is the most prevalent and complicated arrhythmia after open heart surgery. White blood cell (WBC) count seems to be most significantly associated with cardiovascular disorders. This study was designed to evaluate the exact relationship between preoperative WBC count and post-Coronary artery bypass graft (CABG) AF in patients with severe left ventricle (LV) dysfunction who underwent elective off-pump coronary artery bypass.
This study was conducted on 104 patients from among 400 patients with severe LV dysfunction undergoing elective off-pump CABG surgery from February 2011 to February 2012, in Afshar Cardiovascular Center, Yazd, Iran. Patients with emergency surgery, unstable angina creatinine higher than 2.0 mg/dL, malignancy, or immunosuppressive disease were excluded. Preoperative serological tests of the participants, such as WBC counts, were saved in their medical dossiers. Of the 400 patients undergoing CABG, AF was found in 54 cases; these 54 male patients formed the experimental group and 60 other patients in the intensive care unit (ICU) and hospital stay without postoperative AF were part of the control group.
The average age of the patients was 68.5±12.8 years. WBC counts in patients with and without AF three days before surgery were 12,340±155 and 8,950±170, respectively. On surgical day, WBC counts in the patients with and without AF were 13,188±140 and 9,145±255, respectively (P value three days before surgery: 0.04; P value on surgical day: 0.01). Of the 54 male patients with postoperative AF (POAF), duration of AF was more in cases with elevated WBC count (12,000-14,000) than in those with lower elevated WBC count (10,000-12,000) (]P=0.025), but there was no relationship between frequency of recurrence of AF and grading of elevation of WBC count (]P=0.81).
These findings show that three days before surgery and on surgery day, there was a difference in WBC count between both groups. So, preoperative WBC count may predict the incidence and duration of AF; however, it cannot be a predictor of the frequency of recurrence of AF. Finally, WBC count is an independent marker for POAF and duration of AF.
Atrial fibrillation; elective off-pump coronary artery bypass graft; white blood cell count
Purpose: Atrial fibrillation (AF) is the most frequent arrhythmia that follows coronary artery bypass graft (CABG). Patients developing postoperative AF (POAF) have significantly higher mortality rates. The consistent prophylactic effectiveness of statins and vitamin C are well-accepted; however, no evaluation on combined therapy has been performed. We aimed at assessing the efficacy of combination therapy with statin and vitamin C in comparison with statin alone in the prevention of post CABG-AF.
Methods: In a randomized double blind clinical trial, 120 candidates of CABG were recruited in Tabriz Madani Educational Center in a 15-month period of time. Patients were randomized into two groups of 60 receiving oral atorvastatin (40mg) plus oral vitamin C (2g/d operation day and 1g/d for five consequent days) for intervention group and oral atorvastatin (40mg) for control group. Occurrence of post CABG AF was compared between the two groups.
Results: There were 60 patients, 43 males and 17 females with a mean age of 61.0±11.5 (29-78) years, in the intervention group and sixty patients, 39 males and 21 females with a mean age of 60.5±11.3 (39-81) years, in the control group. The post CABG AF occurred in 6 cases (10%) in the interventional group and 15 patients (25%) in the controls (P=0.03, odds ratio=0.33, 95% confidence interval 0.12-0.93).
Conclusion: Based on our findings, combination prophylaxis against post CABG AF with oral atorvastatin plus vitamin C is significantly more effective than single oral atorvastatin.
Atrial Fibrillation; Atorvastatin; Vitamin C; Coronary Artery Bypass Grafting
Influence of fish oil supplementation on postoperative atrial fibrillation (POAF) was inconsistent according to published clinical trials. The aim of the meta-analysis was to evaluate the effects of perioperative fish oil supplementation on the incidence of POAF after cardiac surgery.
Pubmed, Embase and the Cochrane Library databases were searched. Randomized controlled trials (RCTs) assessing perioperative fish oil supplementation for patients undergoing cardiac surgery were identified. Data concerning study design, patient characteristics, and outcomes were extracted. Risk ratio (RR) and weighted mean differences (WMD) were calculated using fixed or random effects models.
Eight RCTs involving 2687 patients were included. Perioperative supplementation of fish oil did not significantly reduce the incidence of POAF (RR = 0.86, 95%CI 0.71 to 1.03, p = 0.11) or length of hospitalization after surgery (WMD = 0.10 days, 95% CI: 0.48 to 0.67 days, p = 0.75). Fish oil supplementation also did not affect the perioperative mortality, incidence of major bleeding or the length of stay in the intensive care unit. Meta-regression and subgroup analyses indicated mean DHA dose in the supplements may be a potential modifier for the effects of fish oil for POAF. For supplements with DHA >1 g/d, fish oil significantly reduced the incidence of POAF; while it did not for the supplements with a lower dose of DHA.
Current evidence did not support a preventative role of fish oil for POAF. However, relative amounts of DHA and EPA in fish oil may be important for the prevention of POAF.
Thoracic epidural anesthesia (TEA) improves analgesia and outcomes after a cardiac surgery. As aging is a risk factor for postoperative pulmonary complications, TEA is of particular importance in elderly patients undergoing coronary artery bypass graft (CABG).
Fifty patients aged 65–75 years; ASA II and III scheduled for elective CABG were included in the study. Patients were randomized to receive either general anesthesia (GA) group alone or GA combined with TEA group. Heart rate (HR), mean arterial pressure (MAP), and central venous pressure were recorded. Total dose of fentanyl μg/kg, aortic cross clamping, cardiopulmonary bypass (CPB) time, time to first awaking and extubation, arterial blood gases, visual analog scale (VAS) score in intensive care unit were reported. Postoperative pulmonary function tests were done.
TEA showed a significant HR and lower MAP compared with the GA group. The total dose of intraoperative fentanyl and nitroglycerine were significantly lower in the TEA. Patients in TEA group have statistically significantly higher PaO2, lower PaCO2, increase in Forced Vital Capacity (FVC) and Forced Expiratory Volume in one second (FEV1)
TEA reduced severity of postoperative pulmonary function and restoration was faster in TEA group in elderly patients undergoing CABG. Also, it resulted in earlier extubation and awakening, better analgesia, lower VAS.
Coronary artery bypass graft; elderly; thoracic epidural anesthesia
Preoperative use of angiotensin blocking drug therapy (ABDT) with ACE-inhibitors or Angiotensin II receptor blockers (ARBs) and its link to occurrence of postoperative atrial fibrillation (POAF), a common marker of poor outcomes after cardiac surgery, remains controversial.
From 1997-2003 10,552 patients underwent coronary artery bypass grafting (CABG) with or without valve surgery. To adjust for differences of clinical characteristics between patients receiving ABDT within 24 hours prior to surgery compared to those who did not, propensity score analyses were conducted.
ABDT was prescribed in 4,795 (45%) prior to surgery of which 1,725 (36%) developed POAF prior to discharge vs. 1908 (33%) of 5,757 patients who have not received ABDT (unadjusted odds ratio [OR] of 1.13 (95% Confidence Interval [CI] 1.05-1.25, p<0.01). In 6744 propensity score matched patients with well balanced co-morbidity profiles, ABDT was not associated with POAF (OR 1.05, CI 0.95-1.16, p=0.38). Stratified analysis within quintiles of propensity score and propensity-adjusted logistic multivariable regression confirmed these findings.
In this large observational study we found no evidence of an association between preoperative angiotensin blockade and the occurrence of postoperative atrial fibrillation. Adequately powered randomized studies are needed to clarify the best strategy of perioperative angiotensin blocking drug therapy in patients with and without guideline-based indications.
It is suggested that the internal thoracic artery (ITA) harvesting technique influences the incidence of sternal wound infection (SWI) after coronary artery bypass graft (CABG). To determine if there is any real difference between skeletonized vs pedicled ITA, we performed a meta-analysis to determine if there is any real difference between these two established techniques in terms of SWI. We performed a systematic review using MEDLINE, EMBASE, CENTRAL/CCTR, SciELO, LILACS, Google Scholar and reference lists of relevant articles to search for studies that compared the incidence of SWI after CABG between skeletonized vs pedicled ITA until June 2012. The principal summary measures were odds ratio (OR) with 95% confidence interval (CI) and P values (statistically significant when <0.05). The ORs were combined across studies using the weighted DerSimonian–Laird random effects model and weighted Mantel–Haenszel fixed effects. Meta-analysis, sensitivity analysis and meta-regression were completed using the software Comprehensive Meta-Analysis version 2 (Biostat, Inc., Englewood, NJ, USA). Twenty-two studies involving 4817 patients (2424 skeletonized; 2393 pedicled) met the eligibility criteria. There was no evidence for important heterogeneity of effects among the studies. The overall OR (95% CI) of SWI showed a statistically significant difference in favour of skeletonized ITA (fixed effect model: OR 0.443, 95% CI 0.323–0.608, P < 0.001; random effect model: OR 0.443, 95% CI 0.323–0.608, P < 0.001). In the sensitivity analysis, the difference in favour of skeletonized ITA was also observed in subgroups such as diabetic, bilateral ITA and diabetic with bilateral ITA; we also observed that there was a difference in the type of study, since non-randomized studies together demonstrated the benefit of skeletonized ITA in comparison with pedicled ITA, but the randomized studies together did not show this difference (although close to statistical significance and with the tendency to favour the skeletonized group). In meta-regression, we observed a statistically significant coefficient for SWI and proportion of diabetic patients (coefficient −0.02, 95% CI −0.03 to −0.01, P = 0.016). In conclusion, skeletonized ITA appears to reduce the incidence of postoperative SWI in comparison with pedicled ITA after CABG, with this effect being modulated by the presence of diabetes.
Meta-analysis; Coronary artery bypass; Mammary arteries; Surgical wound infection
Long‐chain polyunsaturated omega‐3 fatty acids (n‐3 PUFA) demonstrated antiarrhythmic potential in experimental studies. In a large multinational randomized trial (OPERA), perioperative fish oil supplementation did not reduce the risk of postoperative atrial fibrillation (PoAF) in cardiac surgery patients. However, whether presupplementation habitual plasma phospholipid n‐3 PUFA, or achieved or change in n‐3 PUFA level postsupplementation are associated with lower risk of PoAF is unknown.
Methods and Results
In 564 subjects undergoing cardiac surgery between August 2010 and June 2012 in 28 centers across 3 countries, plasma phospholipid levels of eicosapentaenoic acid (EPA), docosapentaenoic acid (DPA), and docosahexaenoic acid (DHA) were measured at enrollment and again on the morning of cardiac surgery following fish oil or placebo supplementation (10 g over 3 to 5 days, or 8 g over 2 days). The primary endpoint was incident PoAF lasting ≥30 seconds, centrally adjudicated, and confirmed by rhythm strip or ECG. Secondary endpoints included sustained (≥1 hour), symptomatic, or treated PoAF; the time to first PoAF; and the number of PoAF episodes per patient. PoAF outcomes were assessed until hospital discharge or postoperative day 10, whichever occurred first. Relative to the baseline, fish oil supplementation increased phospholipid concentrations of EPA (+142%), DPA (+13%), and DHA (+22%) (P<0.001 each). Substantial interindividual variability was observed for change in total n‐3 PUFA (range=−0.7% to 7.5% after 5 days of supplementation). Neither individual nor total circulating n‐3 PUFA levels at enrollment, morning of surgery, or change between these time points were associated with risk of PoAF. The multivariable‐adjusted OR (95% CI) across increasing quartiles of total n‐3 PUFA at enrollment were 1.0, 1.06 (0.60 to 1.90), 1.35 (0.76 to 2.38), and 1.19 (0.64 to 2.20); and for changes in n‐3 PUFA between enrollment and the morning of surgery were 1.0, 0.78 (0.44 to 1.39), 0.89 (0.51 to 1.55), and 1.01 (0.58 to 1.75). In stratified analysis, demographic, medication, and cardiac parameters did not significantly modify these associations. Findings were similar for secondary PoAF endpoints.
Among patients undergoing cardiac surgery, neither higher habitual circulating n‐3 PUFA levels, nor achieved levels or changes following short‐term fish oil supplementation are associated with risk of PoAF.
Clinical Trial Registration
URL: Clinicaltrials.gov Unique identifier: NCT00970489
biomarker; cardiac surgery; omega‐3 fatty acids; postoperative atrial fibrillation; randomized controlled trial
To review: 1) Pathophysiology of postoperative atrial fibrillation (POAF); 2) Risk factors for POAF; 3) Prophylaxis of POAF; 4) Treatment of POAF; and 5) Future directions.
We searched the Medline database for articles published between January, 1966 to September, 2008. We used the following keywords: Atrial fibrillation, Postoperative atrial fibrillation, Coronary Artery Bypass, and antiarrhythmic agents. Additionally, we searched references from all relevant articles.
POAF occurs in 25-60% of patients depending on the type of cardiac surgery performed. POAF generally occurs on postoperative day 2 or 3. POAF is associated with an increased risk of morbidity and mortality, and longer hospital stay. Prophylactic treatments reduce the likelihood of POAF. In patients who experience POAF, rhythm strategies should be used in those who are symptomatic and hemodynamically unstable. All other patients should be managed with rate strategies.
Atrial fibrillation; postoperative atrial fibrillation; coronary artery bypass; antiarrhythmic agents
To examine whether or not off-pump CABG (Coronary Artery Bypass Reduce) reduces the incidence of AF after cardiac surgery.
The study was carried out in 939 consecutive coronary artery disease patients with sinus rhythm from which 383 patients underwent off-pump CABG, and 556 patients were operated through on-pump CABG. All patients were monitored postoperatively during intensive care unit (ICU) stay. Then, the incidence and predictive risk factors of post operative AF (POAF) in two groups were determined and compared with each other.
Overall, the mean age of the patients was 56.0±12.8 years with 234 patients (24.9%) being older than 65 years. POAF developed in 38 patients (9.9%) of the off-pump and in 93 patients (16.7%) of the on-pump CABG. There was significant difference between two groups when considering the incidence of POAF (P=0.002). Among preoperative risk factors, age>65 years had a significant association with the incidence of AF in both groups. This study also showed that most of the POAF cases converted to sinus rhythm after treatment. Moreover, these finding demonstrated that conversion to sinus rhythm is significantly more probable in off-pump group (P=0.006).
A reduced prevalence of POAF could be observed in patients with off-pump as compared with on-pump techniques. Furthermore, conversion to sinus rhythm in off-pump group was significantly more probable than on-pump group.
Off-pump CABG; On-pump CABG; Postoperative Atrial Fibrillation; Risk Factor
We studied potential risk factors for postoperative atrial fibrillation (POAF) in a large cohort of patients who underwent open-heart surgery, evaluating short- and long-term outcome, and we developed a risk-assessment model of POAF.
A retrospective study of 744 patients without prior history of AF who underwent CABG (n = 513), OPCAB (n = 207), and/or AVR (n = 156) at Landspitali Hospital in 2002–2006. Logistic regression analysis was used to study risk factors for POAF, comparing patients with and without POAF.
The rate of POAF was 44%, and was higher following AVR (74%) than after CABG (44%) or OPCAB (35%). In general, patients with POAF were significantly older, were more often female, were less likely to be smokers, had a lower EF, and had a higher EuroSCORE. The use of antiarrythmics was similar in the groups but patients who experienced POAF were less likely to be taking statins. POAF patients also had longer hospital stay, higher rates of complications, and operative mortality (5% vs. 0.7%). In multivariate analysis, AVR (OR 4.4), a preoperative history of cardiac failure (OR 1.8), higher EuroSCORE (OR 1.1), and advanced age (OR 1.1) were independent prognostic factors for POAF. Overall five-year survival was 83% and 93% for patients with and without POAF (p <0.001).
POAF was detected in 44% of patients, which is high compared to other studies. In the future, our assessment score will hopefully be of use in identifying patients at high risk of POAF and lower complications related to POAF.
Postoperative atrial fibrillation; Coronary artery bypass surgery; Atrial valve replacement; Risk factors; Risk assessment; Prophylaxis; Survival
Post-operative atrial fibrillation/flutter (PoAF) commonly complicates cardiac surgery, occurring in 25–60% of patients. PoAF is associated with significant morbidity, higher long-term mortality, and increased healthcare costs. Novel preventive therapies are clearly needed. In experiments and short-term trials, seafood-derived long-chain omega-3 polyunsaturated fatty acids (PUFA) influence several risk factors that might reduce risk of PoAF. A few small and generally underpowered trials have evaluated effects of omega-3-PUFA supplementation on PoAF, with mixed results. The Omega-3 Fatty Acids for Prevention of Post-operative Atrial Fibrillation (OPERA) trial is an appropriately powered, investigator-initiated, randomized, double-blind, placebo-controlled, multinational trial to determine whether peri-operative oral omega-3-PUFA reduces occurrence of PoAF in 1,516 patients undergoing cardiac surgery. Additional aims include evaluation of resource utilization, biologic pathways and mechanisms, postoperative cognitive decline, and safety. Broad inclusion criteria encompass a real-world population of outpatients and inpatients scheduled for cardiac surgery. Treatment comprises a total pre-operative loading dose of 8–10 g of omega-3-PUFA or placebo divided over 2–5 days, followed by 2 g/d until hospital discharge or post-operative day 10, whichever first. Based on anticipated 30% event rate in controls, total enrollment of 1,516 patients (758 per treatment arm) will provide 90% power to detect 25% reduction in PoAF. OPERA will provide invaluable evidence to inform biologic pathways, proof-of-concept that omega-3-PUFA influence cardiac arrhythmias, and potential regulatory standards and clinical use of this simple, inexpensive, and low-risk intervention to prevent PoAF.
Postoperative atrial fibrillation (POAF) is common among surgical patients and associated with a worse outcome. Pathophysiology of POAF is not fully disclosed, and several perioperative factors could be involved. Direct cardiac stimulation from perioperative use of catecholamines or increased sympathetic outflow from volume loss/anaemia/pain may play a role. Metabolic alterations, such as hypo-/hyperglycaemia and electrolyte disturbances, may also contribute to POAF. Moreover, inflammation, both systemic and local, may play a role in its pathogenesis. Strategies to prevent POAF aim at reducing its incidence and ameliorate global outcome of surgical patients. Nonpharmacological prophylaxis includes an adequate control of postoperative pain, the use of thoracic epidural analgesia, optimization of perioperative oxygen delivery, and, possibly, modulation of surgery-associated inflammatory response with immunonutrition and antioxidants. Perioperative potassium and magnesium depletion should be corrected. The impact of those interventions on patients outcome needs to be further investigated.
Glucose-insulin infusions (with potassium [GIK] or without [GI]) have been advocated in the setting of coronary artery bypass graft (CABG) surgery to optimize myocardial glucose use and to minimize ischemic injury.
To conduct a meta-analysis assessing whether the use of GIK/GI infusions perioperatively reduce in-hospital mortality or atrial fibrillation (AF) after CABG surgery.
Electronic databases (Medline, EMBASE and Cochrane Central Register of Controlled Trials [CENTRAL]) and references of retrieved articles were searched for randomized controlled trials that evaluated the effects of GIK or GI infusions, before or during CABG surgery, on in-hospital mortality and/or postoperative AF. Pooled ORs and 95% CIs were calculated for each outcome.
Twenty trials were identified and eligible for review. The summary OR for in-hospital mortality was 0.88 (95% CI 0.56 to 1.40), based on 44 deaths among 2326 patients. While postoperative AF was a more frequent outcome (occurring in 519 of 1540 patients in the 10 trials reporting this outcome), the overall pooled estimate of effect was nonsignificant (OR 0.79, 95% CI 0.54 to 1.15). This latter finding needs to be interpreted cautiously because it is accompanied by significant heterogeneity across trials.
Perioperative use of GIK/GI does not significantly reduce mortality or atrial fibrillation in patients undergoing CABG surgery. Unless future trial data in support of GIK/GI infusions become available, the routine use of these treatments in patients undergoing CABG surgery should be discouraged because the safety of these infusions has not been systematically examined.
Coronary artery bypass graft surgery; GIK; Insulin; Meta-analysis
Atrial fibrillation (AF) is the most common complication of cardiac surgery. Although it is managed easily, it can cause critical hemodynamic instabilities for intensive care patients. This observational study investigated the predictive power of P-wave dispersion (PWD) for the incidence of post cardiac surgery AF.
Among patients undergoing isolated coronary artery bypass grafting surgery (CABG), 52 patients were selected randomly. Before the operation, ejection fraction, regional wall motion abnormality, and mitral regurgitation were determined by echocardiography. Angiographic data provided information about stenosed vessels. PWD was measured before and after CABG. The incidence of post-CABG AF was determined by rhythm monitoring.
There were no significant differences in age, sex, stenosed vessels, maximum P-wave duration, the prevalence of hypertension, smoking, mitral regurgitation, and regional wall motion abnormality between post-CABG AF and non-AF groups (P > 0.05). The mean prevalence of diabetes mellitus in post-CABG AF group was more than non-AF group (P = 0.036). The mean ejection fraction in post-CABG AF group was lower than non-AF group (P < 0.005). The mean PWD in AF group vs. non-AF group before CABG was 47.5 vs. 23.7 ms. The mean values of post-surgical PWD in AF and non-AF groups were 48.10 and 24.4 ms, respectively. Before CABG, the mean ejection fraction value and minimum P-wave duration in AF group were lower than non-AF group (P < 0.005). A reverse relation was present between minimum P wave duration and PWD (P < 0.001). There was a negative association between high ejection fraction values and decreased PWD (P = 0.002).
Our data suggested minimum P wave duration, PWD, and low ejection fraction are as good predictors of AF in patients undergoing isolated CABG. The absence of differences in age, sex, smoking, hypertension, mitral regurgitation, and regional wall motion abnormality in our study was in contrast with other reports. On the other hand, increased rate of post-CABG AF in our diabetic patients with lower ejection fraction supports other studies. Overall, minimum P wave duration, PWD, and low ejection fraction can be used for patient risk stratification of AF after CABG.
Atrial Fibrillation; Coronary Artery Bypass Grafting; P-Wave Dispersion; Predictor