New Onset Postoperative Atrial Fibrillation is Associated with a Long-Term Risk for Stroke and Death Following Cardiac Surgery

Atrial fibrillation in patients undergoing coronary artery surgery is associated with adverse outcome

BACKGROUND

The aim was to determine the association between atrial fibrillation (AF) and outcome in patients undergoing coronary artery bypass grafting (CABG).

METHODS

All patients undergoing CABG between January 2010 and June 2013 were identified in the Swedish Heart Surgery Registry. Outcomes studied were all-cause mortality, cardiovascular mortality, myocardial infarction, congestive heart failure, ischemic stroke, and recurrent AF. Patients with history of AF prior to surgery (preoperative AF) and patients without history of AF but with AF episodes post-surgery (postoperative AF) were compared to patients with no AF using adjusted Cox regression models.

RESULTS

Among 9,107 identified patients, 8.1% (n = 737) had preoperative AF, and 25.1% (n = 2,290) had postoperative AF. Median follow-up was 2.2 years. Compared to no AF, preoperative AF was associated with higher risk of all-cause mortality, adjusted hazard ratio with 95% confidence interval (HR) 1.76 (1.33-2.33); cardiovascular mortality, HR 2.43 (1.68-3.50); and congestive heart failure, HR 2.21 (1.72-2.84). Postoperative AF was associated with risk of all-cause mortality, HR 1.27 (1.01-1.60); cardiovascular mortality, HR 1.52 (1.10-2.11); congestive heart failure, HR 1.47 (1.18-1.83); and recurrent AF, HR 4.38 (2.46-7.78). No significant association was observed between pre- or postoperative AF and risk for myocardial infarction and ischemic stroke.

CONCLUSIONS

Approximately 1 in 3 patients undergoing CABG had pre- or postoperative AF. Patients with pre- or postoperative AF were at higher risk of all-cause mortality, cardiovascular mortality, and congestive heart failure, but not of myocardial infarction or ischemic stroke. Postoperative AF was associated with higher risk of recurrent AF.

Long-term suppression of atrial fibrillation by botulinum toxin injection into epicardial fat pads in patients undergoing cardiac surgery: Three-year follow-up of a randomized study

BACKGROUND

Botulinum toxin (BTX) injections into epicardial fat pads in patients undergoing coronary artery bypass grafting (CABG) has resulted in suppression of atrial fibrillation (AF) during the early postoperative period through 1-year of follow-up in a pilot program.

OBJECTIVE

The purpose of this study was to report 3-year AF patterns by the use of implantable cardiac monitors (ICMs).

METHODS

Sixty patients with a history of paroxysmal AF and indications for CABG were randomized 1:1 to either BTX or placebo injections into 4 posterior epicardial fat pads. All patients received an ICM with regular follow-up for 3 years after surgery. The primary end point of the extended follow-up period was incidence of any atrial tachyarrhythmia after 30 days of procedure until 36 months on no antiarrhythmic drugs. The secondary end points included clinical events and AF burden.

RESULTS

At the end of 36 months, the incidence of any atrial tachyarrhythmia was 23.3% in the BTX group vs 50% in the placebo group (hazard ratio 0.36; 95% confidence interval 0.14-0.88; P = .02). AF burden at 12, 24, and 36 months was significantly lower in the BTX group than in the placebo group: 0.22% vs 1.88% (P = .003), 1.6% vs 9.5% (P < .001), and 1.3% vs 6.9% (P = .007), respectively. In the BTX group, 2 patients (7%) were hospitalized during follow-up compared with 10 (33%) in the placebo group (P = .02).

CONCLUSION

Injection of BTX into epicardial fat pads in patients undergoing CABG resulted in a sustained and substantial reduction in atrial tachyarrhythmia incidence and burden during 3-year follow-up, accompanied by reduction in hospitalizations.

Atrial fibrillation in patients undergoing transcatheter aortic valve implantation: epidemiology, timing, predictors, and outcome

Atrial fibrillation (AF) is a common arrhythmia in patients with aortic stenosis. When these patients are treated medically or by surgical aortic valve replacement, AF is associated with increased risk of adverse events including death. Growing evidence suggests a significant impact of AF on outcomes also in patients with aortic valve stenosis undergoing transcatheter aortic valve implantation (TAVI). Conversely, limited evidence is available regarding the optimal management of this condition. This review aims to summarize prevalence, pathophysiology, prognosis, and treatment of AF in patients undergoing TAVI.

New-Onset Atrial Fibrillation After Coronary Artery Bypass Graft and Long-Term Risk of Stroke: A Meta-Analysis

BACKGROUND

New-onset atrial fibrillation (NOAF) after coronary artery bypass graft is related to an increased short-term risk of stroke and mortality. We investigated whether the long-term risk of stroke is increased.

METHODS AND RESULTS

We performed a systematic review and meta-analysis of studies that included patients who had coronary artery bypass graft and who afterwards developed NOAF during their index admission; these patients did not have previous atrial fibrillation. The primary outcome was risk of stroke at 6 months or more in patients who developed NOAF compared with those who did not. Odds ratios, relative risk, and hazard ratios were considered equivalent; outcomes were pooled on the log-ratio scale using a random-effects model and reported as exponentiated effect-sizes. We included 16 studies, comprising 108 711 participants with a median follow-up period of 2.05 years. Average participant age was 66.8 years, with studies including an average of 74.8% males. There was an increased long-term risk of stroke in the presence of NOAF (unadjusted studies effect-sizes=1.36, 95% confidence interval, 1.12-1.65, P=0.001, adjusted studies effect-sizes=1.25, 95% confidence interval, 1.09-1.42, P=0.001). There was evidence of moderate effect variation because of heterogeneity in studies reporting unadjusted (P=0.021, I2=49.8%) and adjusted data (P=0.081, I2=49.1%), and publication bias in the latter group (Egger's test, P=0.031). Sensitivity analysis on unadjusted data by study quality, design, and surgery did not alter the effect direction.

CONCLUSIONS

Presence of NOAF in patients post-coronary artery bypass graft is associated with increased long-term risk of stroke compared with patients without NOAF. Further studies may show whether the increased risk is mediated by atrial fibrillation and whether anticoagulation reduces risk.

Preclinical efficacy and safety of KCNH2-G628S gene therapy for postoperative atrial fibrillation

BACKGROUND

Postoperative atrial fibrillation (POAF) is the most common complication occurring after cardiac surgery. Multiple studies have shown significantly increased risks of stroke, myocardial infarction, and death associated with POAF. Current prophylaxis strategies are inadequate to eliminate this problem. We examined the preclinical efficacy and safety of KCNH2-G628S gene transfer to prevent POAF.

METHODS

Domestic pigs received AdKCNH2-G628S by epicardial atrial gene painting and atrial pacemaker implantation for continuous-burst pacing to induce atrial fibrillation. In an initial dose-ranging evaluation, 3 pigs received 5 × 1010 to 5 × 1011 virus particles. In the formal study, 16 pigs were randomized to 3 groups: 5 × 1011 virus particles of AdKCNH2-G628S with 20% Pluronic P407 in saline, 20% Pluronic P407 in saline with no virus, and saline alone. Animals were followed with daily efficacy and safety evaluations through the period of peak adenovirus-mediated transgene expression. After 14 days, pacing was discontinued, and the animals were followed in sinus rhythm for an additional 14 days to assess any longer-term toxicity.

RESULTS

In the primary efficacy analysis, the G628S animals exhibited a significant increase in the average time in sinus rhythm compared with the Pluronic control group (59 ± 7% vs 14 ± 6%; P = .009). There was no significant difference between the Pluronic and saline controls (14 ± 6% vs 32 ± 12%; P = .16). Safety assessment showed improved left ventricular function in the G628S animals; otherwise there were no significant differences among the groups in any safety measure.

CONCLUSIONS

These data indicate that KCNH2-G628S gene therapy can successfully and safely reduce the risk of AF.

Postoperative atrial fibrillation: Target for stroke prevention?

Purpose

A substantial number of patients without a history of atrial fibrillation who undergo surgery develop one or more episodes of atrial fibrillation in the first few days after the operation. We studied whether postoperative transient atrial fibrillation is a risk factor for future atrial fibrillation, stroke and death.

Method

We performed a narrative review of the literature on epidemiology, mechanisms, risk of atrial fibrillation, stroke and death after postoperative atrial fibrillation. We reviewed antithrombotic guidelines on this topic and identified gaps in current management.

Findings

Patients with postoperative atrial fibrillation are at high risk of developing atrial fibrillation in the long term. Mortality is also increased. Most, but not all observational studies report a higher risk of stroke. The optimal antithrombotic regimen for patients with postoperative atrial fibrillation has not been defined. The role of lifestyle changes and of surgical occlusion of the left atrial appendage in preventing adverse outcomes after postoperative atrial fibrillation is not established.

Conclusion

Further studies are warranted to establish the optimal strategy to prevent adverse long-term outcomes after transient, postoperative atrial fibrillation.

Storage time of intraoperative transfused allogeneic red blood cells is not associated with new-onset postoperative atrial fibrillation in cardiac surgery

BACKGROUND

Allogeneic red blood cell (RBC) transfusion has been associated with new-onset postoperative atrial fibrillation (POAF) following cardiac surgery. Prolonged storage time of RBC may increase the risk. The primary aim of the study was to evaluate whether the storage time of RBC is associated with development of POAF.

MATERIALS AND METHODS

Pre-, per- and postoperative data were retrieved from the Western Denmark Heart Registry and local blood banks regarding patients who underwent coronary artery bypass surgery, valve surgery or combined procedures in Aalborg or Aarhus University Hospital during 2010-2014. Multiple logistic regression was used to determine the risk of POAF according to transfusion of RBC on the day of surgery. Furthermore, we determined trend in storage time of RBC according to risk of POAF using restricted cubic splines. Patients with a history of preoperative atrial fibrillation, patients who received transfusions preoperative and patients who died at the day of surgery were among excluded patients.

RESULTS

A total of 2,978 patients with a mean age of 66.4 years were included and 609 patients (21%) received RBC transfusion on the day of surgery. POAF developed in 752 patients (25%) and transfused patients were at an increased risk compared with non-transfused patients (adjusted Odds Ratios for patients receiving RBC: 1.37; 95% CI: 1.11-1.69, P-value = 0.004). However, RBC transfusion was not necessarily the cause of POAF and may only be a marker for development of POAF. There was no significant association between storage time of RBC and POAF.

CONCLUSIONS

In contrast to intraoperative allogeneic RBC transfusion in general, increased storage time of RBC is not associated with development of POAF in cardiac surgery.

Efficacy and safety of vitamin C for atrial fibrillation after cardiac surgery: A meta-analysis with trial sequential analysis of randomized controlled trials

OBJECTIVES

Antioxidant supplement is an option in preventing postoperative atrial fibrillation (AF) after cardiac surgery. However, the benefits and adverse effects of vitamin C have not been well assessed. We aimed to systematically evaluate the efficacy and safety of vitamin C in preventing postoperative AF in adult patients after cardiac surgery.

METHODS

PubMed, EMBASE, and the Cochrane library databases from inception to September 2016 were searched. Randomized controlled trials (RCTs) that evaluated the efficacy and safety of vitamin C in preventing postoperative AF in adult patients after cardiac surgery were identified. The primary outcome was the incidence of postoperative AF. Secondary outcomes included the length of intensive care unit (ICU) stay, length of hospital stay, and stroke events.

RESULTS

Eight RCTs incorporating 1060 patients were included. Compared with placebo group, vitamin C treatment was associated with a substantial reduction in postoperative AF (OR, 0.47; 95% CI, 0.36-0.62; evidence rank: moderate), with no significant heterogeneity (I² 44%; P = 0.09). Trial sequential analysis showed that the cumulative Z-curve crossed the trial sequential monitoring boundary for benefit, establishing sufficient and conclusive evidence. In addition, vitamin C administration was not associated with any length of stay, including in the ICU (evidence rank: low) and hospital (evidence rank: low), respectively.

CONCLUSIONS

Short-term treatment with vitamin C is safe, and may reduce the incidence of postoperative AF after cardiac surgery. Future studies as well as more high quality RCTs are still warranted to confirm the effects of different durations of vitamin C on cardiac surgery.

Atrial Fibrillation Is Associated With Increased Mortality in Patients Undergoing Transcatheter Aortic Valve Replacement: Insights From the Placement of Aortic Transcatheter Valve (PARTNER) Trial

BACKGROUND

This study sought to evaluate the impact of atrial fibrillation (AF) on clinical outcomes in patients undergoing transcatheter aortic valve replacement.

METHODS AND RESULTS

Data were evaluated in 1879 patients with baseline and discharge ECGs who underwent transcatheter aortic valve replacement in the Placement of AoRTic TraNscathetER Valve (PARTNER) trial. A total of 1262 patients manifested sinus rhythm (SR) at baseline/SR at discharge, 113 SR baseline/AF discharge, and 470 AF baseline/AF discharge. Patients who converted from SR to AF by discharge had the highest rates of all-cause mortality at 30 days (P<0.0001 across all groups; 14.2% SR/AF versus 2.6% SR/SR; adjusted hazard ratio [HR]=3.41; P=0.0002) and over 2-fold difference at 1 year (P<0.0001 across all groups; 35.7% SR/AF versus 15.8% SR/SR; adjusted HR=2.14; P<0.0001). The presence of AF on baseline or discharge ECG was a predictor of 1-year mortality (adjusted HR=2.14 for SR/AF group and HR=1.88 for AF/AF groups; P<0.0001 for both groups versus SR/SR). For patients discharged in AF, those with lower ventricular response (ie, <90 bpm) experienced less 1-year all-cause mortality (HR=0.74; P=0.04).

CONCLUSIONS

After transcatheter aortic valve replacement, the presence of AF at discharge, and particularly, the conversion to AF by discharge and higher ventricular response are associated with increased mortality. These data underscore the deleterious impact of AF, as well as the need for targeted interventions to improve clinical outcomes, in patients undergoing transcatheter aortic valve replacement.

CLINICAL TRIAL REGISTRATION

URL: http://www.clinicaltrials.gov. Unique identifier: NCT00530894.

Effect of ColchiciNe on the InciDence of Atrial Fibrillation in Open Heart Surgery Patients: END-AF Trial

BACKGROUND

Atrial fibrillation (AF) is a common arrhythmia in patients undergoing cardiac surgery and may result in significant morbidity and increased hospital stay. This study was conducted to determine if colchicine administered preoperatively to patients undergoing cardiac surgery and continued during hospitalization is effective in reducing the incidence of postoperative AF.

METHODS

In this multicenter prospective randomized open-label study, consecutive patients with no history of AF and scheduled to undergo elective cardiac surgery (n = 360) were randomized to colchicine (n = 179) or no-colchicine (n = 181). Main exclusion criteria were history of AF or supraventricular arrhythmias or absence of sinus rhythm at enrolment, and contraindications to colchicine. Colchicine was orally administered 12 to 24 hours preoperatively and continued until hospital discharge. The primary efficacy end point was documented AF lasting more than 5 minutes. Safety end point was colchicine adverse effects.

RESULTS

In-hospital mortality was 3.3%. The primary end point of AF occurred in 63 patients (17.5%): 26 (14.5%) in the colchicine group and 37 (20.5%) in the no-colchicine group (relative risk reduction 29.3% [P = .14]). Diarrhea occurred in 54 patients, 44 (24.6%) on colchicine and 10 (5.5%) on no-colchicine (P < .001). Diarrhea led to discontinuation of colchicine in 23 (52%) of the 44 patients.

CONCLUSION

Colchicine administered preoperatively to patients undergoing cardiac surgery and continued until hospital discharge failed to significantly reduce the incidence of early postoperative AF. Diarrhea was the most common adverse effect of colchicine leading to its discontinuation in more than half of the patients with this adverse effect.

Duration of Postoperative Atrial Fibrillation After Cardiac Surgery Is Associated With Worsened Long-Term Survival

BACKGROUND

Studies of the effects of postoperative atrial fibrillation (poAF) on long-term survival are conflicting, likely because of comorbidities that occur with poAF and the patient populations studied. Furthermore, the effects of poAF duration on long-term survival are poorly understood.

METHODS

We utilized a prospectively collected database on outcomes of cardiac surgery at a large tertiary care institution between August 2001 and December 2010 with survival follow-up through June 2015 to analyze long-term survival of patients with poAF. In addition, we identified patient- and procedure-related variables associated with poAF, and estimated overall comorbidity burden using the Elixhauser comorbidity index. Survival was compared between patients with poAF (n = 513) and a propensity score matched control cohort, both for all patients and separately for subgroups of patients with poAF lasting less than 2 days (n = 218) and patients with prolonged poAF (n = 265).

RESULTS

Patients with poAF were older and had a higher burden of comorbidities. Survival was significantly worse for patients with poAF than for the matched control group (hazard ratio 1.43, 95% confidence interval: 1.11 to 1.86). That was driven by decreased survival among patients with prolonged poAF (hazard ratio 1.97, 95% confidence interval: 1.37 to 2.80), whereas survival of patients with poAF for less than 2 days was not significantly different from that of matched controls (hazard ratio 0.91, 95% confidence interval: 0.60 to 1.39).

CONCLUSIONS

After close matching based on comorbidity burden, prolonged poAF is still associated with decreased survival. Therefore, vigilance is warranted in monitoring and treating patients with prolonged poAF after cardiac surgery.

Very Long-term Outcomes and Predictors of Percutaneous Coronary Intervention with Drug-eluting Stents Versus Coronary Artery Bypass Grafting for Patients with Unprotected Left Main Coronary Artery Disease

BACKGROUND

There are limited data on longer-term outcomes (>5 years) for patients with unprotected left main coronary artery (ULMCA) disease who underwent percutaneous coronary intervention (PCI) in the drug-eluting stents (DES) era. This study aimed at comparing the long-term (>5 years) outcomes of patients with ULMCA disease underwent PCI with DES and coronary artery bypass grafting (CABG) and the predictors of adverse events.

METHODS

All consecutive patients with ULMCA disease treated with DES implantation versus CABG in our center, between January 2003 and July 2009, were screened for analyzing. A propensity score analysis was carried out to adjust for potential confounding between the two groups.

RESULTS

Nine hundred and twenty-two patients with ULMCA disease were enrolled for the analyses (DES = 465 vs. CABG = 457). During the median follow-up of 7.1 years (interquartile range 5.3-8.2 years), no difference was found between PCI and CABG in the occurrence of death (P = 0.282) and the composite endpoint of cardiac death, myocardial infarction (MI) and stroke (P = 0.294). Rates of major adverse cardiac and cerebrovascular events were significantly higher in the PCI group (P = 0.014) in large part because of the significantly higher rate of repeat revascularization (P < 0.001). PCI was correlated with the lower occurrence of stroke (P = 0.004). Multivariate analysis showed ejection fraction (EF) (P = 0.012), creatinine (P = 0.016), and prior stroke (P = 0.031) were independent predictors of the composite endpoint of cardiac death, MI, and stroke in the DES group, while age (P = 0.026) and EF (P = 0.002) were independent predictors in the CABG group.

CONCLUSIONS

During a median follow-up of 7.1 years, there was no difference in the rate of death between PCI with DES implantation and CABG in ULMCA lesions in the patient cohort. CABG group was observed to have significantly lower rates of repeat revascularization but higher stroke rates compared with PCI. EF, creatinine, and prior stroke were independent predictors of the composite endpoint of cardiac death, MI, and stroke in the DES group, while age and EF were independent predictors in the CABG group.

Cognitive Dysfunction, Delirium, and Stroke in Cardiac Surgery Patients

Neurologic injury in the form of cognitive decline, delirium, and stroke are common phenomena in patients undergoing cardiac surgery and continues to be one of the most common complication after cardiac surgery, in spite of improvements in mortality and and improved surgical and anesthetic techniques. These complications lead to a significant increase in length of stay in the intensive care unit, increased length of hospital admission, and functional impairment, resulting in not only profound negative effects on patients who experience these complications, but also to increased costs of medical care and delivery. We discuss each of these complications in regard to their risks factors, incidence, potential therapeutic modalities, and relevant intraoperative and postoperative considerations.

Identifying postoperative atrial fibrillation in cardiac surgical patients posthospital discharge, using iPhone ECG: a study protocol

INTRODUCTION

Postoperative atrial fibrillation (AF) occurs in 30-40% of patients after cardiac surgery. Identification of recurrent postoperative AF is required to initiate evidence-based management to reduce the risk of subsequent stroke. However, as AF is often asymptomatic, recurrences may not be detected after discharge. This study determines feasibility and impact of a self-surveillance programme to identify recurrence of postoperative AF in the month of posthospital discharge.

METHODS AND ANALYSIS

This is a feasibility study, using a cross-sectional study design, of self-screening for AF using a hand-held single-lead iPhone electrocardiograph device (iECG). Participants will be recruited from the cardiothoracic surgery wards of the Royal North Shore Hospital and North Shore Private Hospital, Sydney, Australia. Cardiac surgery patients admitted in sinus rhythm and experiencing a transient episode of postoperative AF will be eligible for recruitment. Participants will be taught to take daily ECG recordings for 1 month posthospital discharge using the iECG and will be provided education regarding AF, including symptoms and health risks. The primary outcome is the feasibility of patient self-monitoring for AF recurrence using an iECG. Secondary outcomes include proportion of patients identified with recurrent AF; estimation of stroke risk and patient knowledge. Process outcomes and qualitative data related to acceptability of patient's use of the iECG and sustainability of the screening programme beyond the trial setting will also be collected.

ETHICS AND DISSEMINATION

Primary ethics approval was received on 25 February 2014 from Northern Sydney Local Health District Human Resource Ethics Committee, and on 17 July 2014 from North Shore Private Hospital Ethics Committee. Results will be disseminated via forums including, but not limited to, peer-reviewed publications and presentation at national and international conferences.

TRIAL REGISTRATION NUMBER

ACTRN12614000383662.

Predicting New-Onset Postoperative Atrial Fibrillation in Cardiac Surgery Patients

OBJECTIVE

To derive a simple clinical prediction rule identifying patients at high risk of developing new-onset postoperative atrial fibrillation (POAF) after cardiac surgery.

DESIGN

Retrospective analysis on prospectively collected observational data.

SETTING

A university-affiliated cardiac hospital.

PARTICIPANTS

Adult patients undergoing coronary artery bypass grafting and/or valve surgery.

INTERVENTIONS

Observation for the occurrence of new-onset postoperative atrial fibrillation.

MEASUREMENTS AND MAIN RESULTS

Details on 28 preoperative variables from 999 patients were collected and significant predictors (p<0.2) were inserted into multivariable logistic regression and reconfirmed with recursive partitioning. A total of 305 (30.5%) patients developed new-onset POAF. Eleven variables were associated significantly with atrial fibrillation. A multivariable logistic regression model included left atrial dilatation, mitral valve disease, and age. Coefficients from the model were converted into a simple 7-point predictive score. The risk of POAF per score is: 15.0%, if 0; 20%, if 1; 27%, if 2; 35%, if 3; 44%, if 4; 53%, if 5; 62%, if 6; and 70%, if 7. A score of 4 has a sensitivity of 44% and a specificity of 82% for POAF. A score of 6 has a sensitivity of 11% and a specificity of 97%. Bootstrapping with 5,000 samples confirmed the final model provided consistent predictions.

CONCLUSIONS

This study proposed a simple predictive score incorporating three risk variables to identify cardiac surgical patients at high risk of developing new-onset POAF. Preventive treatment should target patients ≥ 65 years with left atrial dilatation and mitral valve disease.

Postoperative atrial fibrillation impacts on costs and one-year clinical outcomes: the Veterans Affairs Randomized On/Off Bypass Trial

BACKGROUND

New-onset postoperative atrial fibrillation (POAF) after coronary artery bypass graft surgery (CABG) is associated with worse in-hospital morbidity and mortality, extended hospital stays, and higher costs. Beyond the initial hospital discharge, the cost and outcomes of POAF have not been well studied.

METHODS

For CABG patients with and without new-onset POAF, a retrospective propensity-matched, multivariable regression analysis was performed to compare 1-year outcomes (including health-related quality of life [HRQoL] scores and mortality rates) and costs (standardized to 2010 dollars). Regression models controlled for site and patient factors, with propensity matching used to adjust for differences in POAF versus no-POAF patients' risk profiles.

RESULTS

Using the existing CABG trial database, 2,096 patient records were analyzed, including POAF patients (n = 549) versus no-POAF patients (n = 1,547). For the index CABG hospitalization, POAF patients had longer postoperative length of stay (+3.9 days) and higher discharge costs (+$13,993) than no-POAF patients. At 1 year, POAF patients had more than twice the adjusted odds of dying (p < 0.01), with higher 1-year total cumulative costs. This 1-year cost difference (+$15,593) was largely attributable to hospital-based costs during the index surgery hospitalization. There was no difference in 1-year HRQoL scores (or HRQoL score changes) between POAF patients and no-POAF patients.

CONCLUSIONS

Compared with no-POAF patients, POAF patients had higher discharge and 1-year costs along with higher 1-year mortality rates, but no differences were observed in 1-year HRQoL scores. Additional research appears warranted to improve the longer-term survival rates for POAF CABG patients, targeting future POAF-specific postdischarge interventions.

Perioperative atrial fibrillation and the long-term risk of ischemic stroke

IMPORTANCE

Clinically apparent atrial fibrillation increases the risk of ischemic stroke. In contrast, perioperative atrial fibrillation may be viewed as a transient response to physiological stress, and the long-term risk of stroke after perioperative atrial fibrillation is unclear.

OBJECTIVE

To examine the association between perioperative atrial fibrillation and the long-term risk of stroke.

DESIGN, SETTING, AND PARTICIPANTS

Retrospective cohort study using administrative claims data on patients hospitalized for surgery (as defined by surgical diagnosis related group codes), and discharged alive and free of documented cerebrovascular disease or preexisting atrial fibrillation from nonfederal California acute care hospitals between 2007 and 2011. Patients undergoing cardiac vs other types of surgery were analyzed separately.

MAIN OUTCOMES AND MEASURES

Previously validated diagnosis codes were used to identify ischemic strokes after discharge from the index hospitalization for surgery. The primary predictor variable was atrial fibrillation newly diagnosed during the index hospitalization, as defined by previously validated present-on-admission codes. Patients were censored at postdischarge emergency department encounters or hospitalizations with a recorded diagnosis of atrial fibrillation.

RESULTS

Of 1,729,360 eligible patients, 24,711 (1.43%; 95% CI, 1.41%-1.45%) had new-onset perioperative atrial fibrillation during the index hospitalization and 13,952 (0.81%; 95% CI, 0.79%-0.82%) experienced a stroke after discharge. At 1 year after hospitalization for cardiac surgery, cumulative rates of stroke were 0.99% (95% CI, 0.81%-1.20%) in those with perioperative atrial fibrillation and 0.83% (95% CI, 0.76%-0.91%) in those without atrial fibrillation. At 1 year after noncardiac surgery, cumulative rates of stroke were 1.47% (95% CI, 1.24%-1.75%) in those with perioperative atrial fibrillation and 0.36% (95% CI, 0.35%-0.37%) in those without atrial fibrillation. In a Cox proportional hazards analysis accounting for potential confounders, perioperative atrial fibrillation was associated with subsequent stroke both after cardiac surgery (hazard ratio, 1.3; 95% CI, 1.1-1.6) and noncardiac surgery (hazard ratio, 2.0; 95% CI, 1.7-2.3). The association was significantly stronger for perioperative atrial fibrillation after noncardiac vs cardiac surgery (P < .001 for interaction).

CONCLUSIONS AND RELEVANCE

Among patients hospitalized for surgery, perioperative atrial fibrillation was associated with an increased long-term risk of ischemic stroke, especially following noncardiac surgery.

Anticoagulation strategies for the management of postoperative atrial fibrillation

Patients undergoing thoracic and cardiac procedures are at the highest risk for postoperative atrial fibrillation (POAF). POAF is associated with poor short-term and long-term outcomes, including high rates of early and late stroke, and late mortality. Patients with POAF that persists for longer than 48 hours should be anticoagulated on warfarin. Three new oral anticoagulants are available for the treatment of nonvalvular atrial fibrillation and have been found to be as efficacious or superior to warfarin in the prevention of stroke in high-risk patients, with similar to lower rates of major bleeding, and lower rates of intracranial hemorrhage.

Postcardioplegia ventricular fibrillation: no impact on subsequent survival

OBJECTIVES

At aortic declamping after cardioplegic cardiac arrest, the initial rhythm can be broadly classified as ventricular fibrillation (VF) or non-VF. VF can be treated with potassium-induced conversion and direct-current countershock is only applied if potassium treatment fails. We aimed to investigate whether there are any differences between these groups of patients in regard to outcomes.

DESIGN

From January 1999 through December 2010, 12,113 patients underwent various types of cardiac surgery. Data from every patient were consecutively registered. Survival was established through the Norwegian National Registry. Cox multivariable modeling with adjustment for clinical, biochemical, and medication baseline data was used for survival analysis.

RESULTS

The mean follow-up time was 7.4 years and total patient-years were 89,268. The percentage of all-cause deaths was 24.9. Adjusted survival for patients with no postcardioplegia VF (n = 9723) and patients with successful potassium-induced conversion (n = 1877) was completely identical. Four hundred patients with electrical conversion after failed potassium treatment had a nonsignificant trend toward an increased mortality (hazard ratio, 95% confidence interval: 1.19 (0.99-1.4); p = 0.07).

CONCLUSIONS

This is the first study reporting the association between postcardioplegia VF, its treatment with potassium and outcome. No impact was found on outcome as judged by all-cause mortality.

A novel treatment strategy of new onset atrial fibrillation after cardiac surgery: an observational prospective study

OBJECTIVE

The aim of this prospective observational study was to evaluate the efficiency of a new escalating treatment strategy with vernakalant, flecainide and electrical cardioversion (EC) in patients with new onset atrial fibrillation (AF) after cardiac surgery.

MATERIAL AND METHODS

24 patients with new onset AF after aortic valve surgery, coronary artery bypass surgery or combined procedures were evaluated in this study. Additional including criteria were age between 18 and 80, duration of AF less than four days, body weight less than 100 kg and no previous treatment with class I or III antiarrhythmic drugs. Exclusion criteria were poor left ventricular ejection fraction (LVEF < 40%) and history of myocardial infarction within 30 days. The patients were divided into converters and non-converters according to their response to combination treatment with vernakalant and flecainide, and the groups were compared.

RESULTS

The mean age of the population was 69.6 ± 6.3 years and 26.1% of patients were female. There were no statistically significant differences between the two groups in terms of height, weight, gender distribution, comorbidities, preoperative medication, left ventricular function and left atrium diameter. Interventricular septum (IVS) in the non-converted group was significantly thicker compared to the converted group: 14.0 ± 1.00 vs. 10.40 ± 2.59 mm (p = 0.036). While 14 patients (60.9%) were successfully converted into stable sinus rhythm by pharmacological treatment with vernakalant and flecainide, 9 patients (39.1%, non-converted group) remained in AF. However, seven of them could be converted after additional EC.

CONCLUSION

The combination of vernakalant and flecainide improves the conversion rate into a stable sinus rhythm in postcardiotomy patients with new onset AF compared to single drug therapy. Furthermore it might be an excellent precondition for successful EC in patients who are not converted after using both antiarrhtythmic drugs. Furthermore, left ventricular hypertrophy might be a potential negative predictor of successful pharmacological cardioversion.

Risks of Stroke After Coronary Artery Bypass Graft - Recent Insights and Perspectives

Stroke is one of the most devastating complications after coronary artery bypass graft (CABG) surgery, entailing permanent disability, a 3-6 fold increased risk of mortality, an incremental hospital resource consumption and a longer length of hospital stay. Notwithstanding advances in surgical, anaesthetic and medical management across the last 10 years, the risk of stroke after CABG has not significantly declined, likely because an older and sicker population is now deemed suitable to undergo CABG. The pathogenesis of stroke is multifactorial, but two variables are believed to play a major role - cerebral embolisation of atheromatous debris arising from the ascending aorta during surgical manipulation and hypoperfusion during surgery. Identification of vulnerable patients at increased risk of stroke before CABG is of paramount importance for the surgical decision-making approach and informed consent. Several models including demographic, clinical and procedural variables have been developed to risk-stratify the hazard of stroke in patients undergoing CABG, but identification of severe atherosclerosis of the ascending aorta and pre-existing cerebrovascular disease are key determinants for appropriate risk stratification and decision-making. Atherosclerotic disease of the ascending aorta can be identified before surgery using transoesophageal echocardiography, computed tomography and magnetic resonance imaging. However, intra-operative ultrasound scanning of the ascending aorta is the diagnostic tool with the best sensitivity and specificity for the detection of atheromatous debris in the ascending aorta. Although many investigators have advocated the use of off-pump CABG to minimise the risk of peri-operative stroke, results from randomised trials and meta-analyses have been inconsistent. Anaortic approaches, including total arterial revascularisation with in situ grafting of both mammary arteries, or the use of the HEARTSTRING® seal device avoid any manipulation of the aorta, thus potentially minimising the risk of stroke in high-risk patients. Assessment and treatment of severe carotid artery disease, and aggressive and prompt treatment of post-operative atrial fibrillation are other important strategies that should be routinely implemented to reduce the risk of stroke in patients undergoing CABG.