Atrial fibrillation independently prolongs hospital stay after coronary artery bypass surgery

A Systematic Review of Ongoing Registered Research Studies on Post-Operative Atrial Fibrillation after Cardiac Surgery

Background/Objectives: New-onset atrial fibrillation (AF) after cardiac surgery is associated with patient-important outcomes. Uncertainty persists regarding its prevention, detection, and management. This review seeks to identify, compile, and describe ongoing registered research studies involving patients with or at risk for post-operative AF (POAF) after cardiac surgery. Methods: We searched clinical trial registries in January 2023 for studies focusing on POAF prediction, prevention, detection, or management. We extracted data from each record and performed descriptive analyses. Results: In total, 121 studies met the eligibility criteria, including 82 randomized trials. Prevention studies are the most common (n = 77, 63.6%), followed by prediction (n = 21, 17.4%), management (n = 16, 13.2%), and detection studies (n = 7, 5.8%). POAF after cardiac surgery is an area of active research. Conclusions: There are many ongoing randomized prevention studies. However, two major clinical gaps persist; future randomized trials should compare rate and rhythm control in patients who develop POAF, and long-term follow-up studies should investigate strategies to monitor for AF recurrence in patients with POAF.

Prevention of postoperative atrial fibrillation in cardiac surgery: a quality improvement project

PURPOSE

Postoperative atrial fibrillation (POAF) has an incidence of 20-60% in cardiac surgery. The Society of Cardiovascular Anesthesiologists and the European Association of Cardiothoracic Anaesthesiology Practice Advisory have recommended postoperative beta blockers and amiodarone for the prevention of POAF. By employing quality improvement (QI) strategies, we sought to increase the use of these agents and to reduce the incidence of POAF among our patients undergoing cardiac surgery.

METHODS

This single-centre QI initiative followed the traditional Plan, Do, Study, Act (PDSA) cycle scientific methodology. A POAF risk score was developed to categorize all patients undergoing cardiac surgery as either normal or elevated risk. Risk stratification was incorporated into a preprinted prescribing guide, which recommended postoperative beta blockade for all patients and a postoperative amiodarone protocol for patients with elevated risk starting on postoperative day one (POD1). A longitudinal audit of all patients undergoing cardiac surgery was conducted over 11 months to track the use of prophylactic medications and the incidence of POAF.

RESULTS

Five hundred and sixty patients undergoing surgery were included in the QI initiative from 1 December 2020 to 1 November 2021. The baseline rate of POAF across all surgical subtypes was 39% (198/560). The use of prophylactic amiodarone in high-risk patients increased from 13% (1/8) at the start of the project to 41% (48/116) at the end of the audit period. The percentage of patients receiving a beta blocker on POD1 did fluctuate, but remained essentially unchanged throughout the audit (34.8% in December 2020 vs 46.7% in October 2021). After 11 months, the overall incidence of POAF was 29% (24.9% relative reduction). Notable reductions in the incidence of POAF were observed in more complex surgical subtypes by the end of the audit, including multiple valve replacement (89% vs 56%), aortic repair (50% vs 33%), and mitral valve surgery (45% vs 33%).

CONCLUSIONS

This single-centre QI intervention increased the use of prophylactic amiodarone by 28% for patients at elevated risk of POAF, with no change in the early postoperative initiation of beta blockers (46.7% of patients by POD1). There was a notable reduction in the incidence of POAF in patients at elevated risk undergoing surgery.

Differences in Postoperative Atrial Fibrillation Incidence and Outcomes After Cardiac Surgery According to Assessment Method and Definition: A Systematic Review and Meta-Analysis

BACKGROUND

Postoperative atrial fibrillation (POAF) is the most frequent complication of cardiac surgery. Despite clinical and economic implications, ample variability in POAF assessment method and definition exist across studies. We performed a study-level meta-analysis to evaluate the influence of POAF assessment method and definition on its incidence and association with clinical outcomes.

METHODS AND RESULTS

A systematic literature search was conducted to identify studies comparing the outcomes of patients with and without POAF after cardiac surgery that also reported POAF assessment method. The primary outcome was POAF incidence. The secondary outcomes were in-hospital mortality, stroke, intensive care unit length of stay, and postoperative length of stay. Fifty-nine studies totaling 197 774 patients were included. POAF cumulative incidence was 26% (range: 7.3%-53.1%). There were no differences in POAF incidence among assessment methods (27%, [range: 7.3%-53.1%] for continuous telemetry, 27% [range: 7.9%-50%] for telemetry plus daily ECG, and 19% [range: 7.8%-42.4%] for daily ECG only; P>0.05 for all comparisons). No differences in in-hospital mortality, stroke, intensive care unit length of stay, and postoperative length of stay were found between assessment methods. No differences in POAF incidence or any other outcomes were found between POAF definitions. Continuous telemetry and telemetry plus daily ECG were associated with higher POAF incidence compared with daily ECG in studies including only patients undergoing isolated coronary artery bypass grafting.

CONCLUSIONS

POAF incidence after cardiac surgery remains high, and detection rates are variable among studies. POAF incidence and its association with adverse outcomes are not influenced by the assessment method and definition used, except in patients undergoing isolated coronary artery bypass grafting.

Cardiopulmonary bypass management and risk of new-onset atrial fibrillation after cardiac surgery

OBJECTIVES

Cardiopulmonary bypass (CPB) management may potentially play a role in the development of new-onset atrial fibrillation (AF) after cardiac surgery. The aim of this study was to explore this potential association.

METHODS

Patients who underwent coronary artery bypass grafting and/or valvular surgery during 2016-2020 were included in an observational single-centre study. Data collected from the Swedish Web System for Enhancement and Development of Evidence-Based Care in Heart Disease Evaluated According to Recommended Therapies registry and a local CPB database were merged. Associations between individual CPB variables (CPB and aortic clamp times, arterial and central venous pressure, mixed venous oxygen saturation, blood flow index, bladder temperature and haematocrit) and new-onset AF were analysed using multivariable logistic regression models adjusted for patient characteristics, comorbidities and surgical procedure.

RESULTS

Out of 1999 patients, 758 (37.9%) developed new-onset AF. Patients with new-onset postoperative AF were older, had a higher incidence of previous stroke, worse renal function and higher EuroSCORE II and CHA2DS2-VASc scores and more often underwent valve surgery. Longer CPB time [adjusted odds ratio 1.05 per 10 min (95% confidence interval 1.01-1.08); P = 0.008] and higher flow index [adjusted odds ratio 1.21 per 0.2 l/m2 (95% confidence interval 1.02-1.42); P = 0.026] were associated with an increased risk for new-onset AF, while the other variables were not. A sensitivity analysis only including patients with isolated coronary artery bypass grafting supported the primary analyses.

CONCLUSIONS

CPB management following current guideline recommendations appears to have minor or no influence on the risk of developing new-onset AF after cardiac surgery.

Patterns of cytokine release and association with new onset of post-cardiac surgery atrial fibrillation

Introduction

Postoperative Atrial Fibrillation (POAF) is a common complication of cardiac surgery, associated with increased mortality, stroke risk, cardiac failure and prolonged hospital stay. Our study aimed to assess the patterns of release of systemic cytokines in patients with and without POAF.

Methods

A post-hoc analysis of the Remote Ischemic Preconditioning (RIPC) trial, including 121 patients (93 males and 28 females, mean age of 68 years old) who underwent isolated coronary artery bypass grafting (CABG) and aortic valve replacement (AVR). Mixed-effect models were used to analyze patterns of release of cytokines in POAF and non-AF patients. A logistic regression model was used to assess the effect of peak cytokine concentration (6 h after the aortic cross-clamp release) alongside other clinical predictors on the development of POAF.

Results

We found no significant difference in the patterns of release of IL-6 (p = 0.52), IL-10 (p = 0.39), IL-8 (p = 0.20) and TNF-α (p = 0.55) between POAF and non-AF patients. Also, we found no significant predictive value in peak concentrations of IL-6 (p = 0.2), IL-8 (p = >0.9), IL-10 (p = >0.9) and Tumour Necrosis Factor Alpha (TNF-α)(p = 0.6), however age and aortic cross-clamp time were significant predictors of POAF development across all models.

Conclusions

Our study suggests no significant association exists between cytokine release patterns and the development of POAF. Age and Aortic Cross-clamp time were found to be significant predictors of POAF.

Atrial fibrillation after cardiac surgery: A systematic review and meta-analysis

OBJECTIVE

New-onset postoperative atrial fibrillation (POAF) after cardiac surgery is common, with rates up to 60%. POAF has been associated with early and late stroke, but its association with other cardiovascular outcomes is less known. The objective was to perform a meta-analysis of the studies reporting the association of POAF with perioperative and long-term outcomes in patients with cardiac surgery.

METHODS

We performed a systematic review and a meta-analysis of studies that presented outcomes for cardiac surgery on the basis of the presence or absence of POAF. MEDLINE, EMBASE, and the Cochrane Library were assessed; 57 studies (246,340 patients) were selected. Perioperative mortality was the primary outcome. Inverse variance method and random model were performed. Leave-one-out analysis, subgroup analyses, and metaregression were conducted.

RESULTS

POAF was associated with perioperative mortality (odds ratio [OR], 1.92; 95% confidence interval [CI], 1.58-2.33), perioperative stroke (OR, 2.17; 95% CI, 1.90-2.49), perioperative myocardial infarction (OR, 1.28; 95% CI, 1.06-1.54), perioperative acute renal failure (OR, 2.74; 95% CI, 2.42-3.11), hospital (standardized mean difference, 0.80; 95% CI, 0.53-1.07) and intensive care unit stay (standardized mean difference, 0.55; 95% CI, 0.24-0.86), long-term mortality (incidence rate ratio [IRR], 1.54; 95% CI, 1.40-1.69), long-term stroke (IRR, 1.33; 95% CI, 1.21-1.46), and longstanding persistent atrial fibrillation (IRR, 4.73; 95% CI, 3.36-6.66).

CONCLUSIONS

The results suggest that POAF after cardiac surgery is associated with an increased occurrence of most short- and long-term cardiovascular adverse events. However, the causality of this association remains to be established.

Comparative effectiveness of metoprolol, ivabradine, and its combination in the management of inappropriate sinus tachycardia in coronary artery bypass graft patients

BACKGROUND:

Inappropriate sinus tachycardia (IST) is an arrhythmic complication observed after coronary artery bypass graft (CABG) surgery which left untreated, commonly increases chances of postoperative stroke. The primary study objective was comparing effectiveness of beta blocker-metoprolol; a specific I_f blocker-ivabradine and its combination in patients who develop IST as a complication following CABG.

MATERIALS AND METHODS:

An open-labeled, investigator initiated, clinical study was conducted on 150 patients who developed IST (heart rate [HR] >100 beats/min) following elective CABG surgery. The patients were randomized into three treatment groups. Group I – received ivabradine (5 mg), Group II – metoprolol (25 mg), and Group III – ivabradine (5 mg) and metoprolol (25 mg). Treatment was given orally, twice a day for 7 days in all the three groups postoperatively. Primary endpoints were comparative effectiveness in HR and blood pressure reduction following treatment.

RESULTS:

IST was diagnosed by an electrocardiogram (12-lead) considering morphological features of P-wave and with 32% increase from baseline HR in all the three groups. Compared to IST arrthymic rate, HR was reduced in all groups following respective treatment (P = 0.05). Reduction in HR was significant (P < 0.05) in combination group followed by ivabradine which was significantly greater than metoprolol treated group. None of the treatments clinically changed the systolic, diastolic and mean blood pressure till discharge. No surgery/treatment-related complications were observed in any groups.

CONCLUSION:

Ivabradine stands as a pharmacological option for controlling HR and rhythm without associated side effects in postoperative CABG patients with IST.

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

Background

Studies using 1 mg of colchicine to prevent postoperative atrial fibrillation (POAF) reported conflicting results. Moreover, colchicine was associated with significant gastrointestinal (GI) side effects. This study examined whether low-dose colchicine effectively prevents POAF and whether low-dose therapy is associated with lower rates of colchicine-induced GI side effects.

Methods

In this prospective, randomized, double-blind, placebo-controlled study, consecutive adult patients admitted for elective cardiac surgeries randomly received a 1-mg dose of colchicine (n = 81) or placebo (n = 71) orally 12 to 24 hours before surgery followed by a daily dose of 0.5 mg until hospital discharge. The primary efficacy endpoint was the development of at least one episode of POAF of ≥5 minutes. The primary safety endpoint was the development of adverse events, especially diarrhea.

Results

The in-hospital mortality rate was 3.9%. POAF occurred in 13 patients (16.1%) in the colchicine group and 13 patients (18.3%) in the placebo group (odds ratio 0.85 [95% Confidence Interval = 0.37−1.99]). Diarrhea occurred in two patients in each group and necessitated treatment discontinuation in one patient in each group.

Conclusion

Low-dose colchicine did not prevent POAF in patients undergoing cardiac surgery. These results should be interpreted cautiously because of the small sample size and early study termination.

ClinicalTrials.gov Unique Identifier number: NCT03015831

Dexmedetomidine for reduction of atrial fibrillation and delirium after cardiac surgery (DECADE): a randomised placebo-controlled trial

BACKGROUND

Atrial fibrillation and delirium are common consequences of cardiac surgery. Dexmedetomidine has unique properties as sedative agent and might reduce the risk of each complication. This study coprimarily aimed to establish whether dexmedetomidine reduces the incidence of new-onset atrial fibrillation and the incidence of delirium.

METHODS

A randomised, placebo-controlled trial was done at six academic hospitals in the USA. Patients who had had cardiac surgery with cardiopulmonary bypass were enrolled. Patients were randomly assigned 1:1, stratified by site, to dexmedetomidine or normal saline placebo. Randomisation was computer generated with random permuted block size 2 and 4, and allocation was concealed by a web-based system. Patients, caregivers, and evaluators were all masked to treatment. The study drug was prepared by the pharmacy or an otherwise uninvolved research associate so that investigators and clinicians were fully masked to allocation. Participants were given either dexmedetomidine infusion or saline placebo started before the surgical incision at a rate of 0·1 μg/kg per h then increased to 0·2 μg/kg per h at the end of bypass, and postoperatively increased to 0·4 μg/kg per h, which was maintained until 24 h. The coprimary outcomes were atrial fibrillation and delirium occurring between intensive care unit admission and the earlier of postoperative day 5 or hospital discharge. All analyses were intention-to-treat. The trial is registered with ClinicalTrials.gov, NCT02004613 and is closed.

FINDINGS

798 patients of 3357 screened were enrolled from April 17, 2013, to Dec 6, 2018. The trial was stopped per protocol after the last designated interim analysis. Among 798 patients randomly assigned, 794 were analysed, with 400 assigned to dexmedetomidine and 398 assigned to placebo. The incidence of atrial fibrillation was 121 (30%) in 397 patients given dexmedetomidine and 134 (34%) in 395 patients given placebo, a difference that was not significant: relative risk 0·90 (97·8% CI 0·72, 1·15; p=0·34). The incidence of delirium was non-significantly increased from 12% in patients given placebo to 17% in those given dexmedetomidine: 1·48 (97·8% CI 0·99-2·23). Safety outcomes were clinically important bradycardia (requiring treatment) and hypotension, myocardial infarction, stroke, surgical site infection, pulmonary embolism, deep venous thrombosis, and death. 21 (5%) of 394 patients given dexmedetomidine and 8 (2%) of 396 patients given placebo, had a serious adverse event as determined by clinicians. 1 (<1%) of 391 patients given dexmedetomidine and 1 (<1%) of 387 patients given placebo died.

INTERPRETATION

Dexmedetomidine infusion, initiated at anaesthetic induction and continued for 24 h, did not decrease postoperative atrial arrhythmias or delirium in patients recovering from cardiac surgery. Dexmedetomidine should not be infused to reduce atrial fibrillation or delirium in patients having cardiac surgery.

FUNDING

Hospira Pharmaceuticals.

Association between new-onset postoperative atrial fibrillation and 1-year mortality in elderly patients after hip arthroplasty

BACKGROUND

The purpose of this study is to determine whether new-onset postoperative atrial fibrillation (NOPAF) among patients after hip arthroplasty can predict 1-year mortality.

METHODS

All patients over 65 years who underwent hip arthroplasty from January 2013 to December 2017 in a Chinese tertiary hospital were retrospectively analyzed. Patients with paroxysmal and persistent atrial fibrillation were ruled out. 2438 patients were identified to be eligible. The primary endpoint was 1-year mortality after the arthroplasty.

RESULTS

Among the 2438 patients, 101 (4.1%) had NOPAF and 2337 (95.9%) had not. Only the current use of beta blocker could predict the occurrence of NOPAF after hip arthroplasty. 1-year mortality for patients with NOPAF was significantly higher than that for patients without NOPAF (70.3% vs 19.0%; p < 0.001). Anti-arrhythmic and anticoagulant treatments were related to 1-year mortality, respectively. With multivariate analysis, NOPA was the most significant variable related to 1-year mortality (hazard ratio 7.8, 95% CI 2.9-24.6).

CONCLUSIONS

Among elderly patients after hip arthroplasty, 1-year mortality is increased significantly for patients with NOPAF.

Atrial Fibrillation Post Coronary Artery Graft Surgery: A Review Of Literature

Atrial fibrillation (AF) is a failure that is observed in heart disease and is also known to be the most common heart rhythm disturbance post coronary artery bypass surgery. Although AF is considered a transient problem, it is usually accompanied with a variety of complications and morbidity for patients and may result in death. In the present study, pre- and post-operative considerable factors which may increase the risk and mortality of AF, and possible treatments have been concisely reviewed.

Effects of high-dose vitamin D supplementation on the occurrence of post-operative atrial fibrillation after coronary artery bypass grafting: randomized controlled trial

OBJECTIVE

This study aimed to investigate the preventive effects of a high-dose vitamin D administered preoperatively on the post-operative atrial fibrillation (POAF) occurrence in patients with insufficient or deficient serum vitamin D levels who underwent coronary artery bypass grafting (CABG) surgery.

METHODS

The study was a randomized controlled, blinded and parallel-arm trial conducted on 116 who had vitamin D deficiency or insufficiency during the pre-operative evaluation were included in the study conducted between January 2018 and January 2019. Patients were divided into those who received oral vitamin D (treatment group; n = 58) and those who did not (control group; n = 58) 48 h before CABG surgery. In the treatment group, patients with vitamin D deficiency were administered 300.000 IU vitamin D orally and those with vitamin D insufficiency 150.000 IU 48 h preoperatively. Patients were followed up during hospitalisation process with respect to POAF.

RESULTS

Both groups showed no significant differences with regard to age, gender, body mass index, creatine level, left atrial diameter, pre-operative drug use, calcium level, ejection fraction, diabetes mellitus and hypertension. The ratio of POAF occurrence found in the treatment and control groups were 12.07% and 27.59%, respectively. Vitamin D treatment was found to reduce the risk of POAF development by 0.24 times (p = 0.034).

CONCLUSION

In this study with sufficient sample size, preoperative short-term high-dose vitamin D supplementation was found to be significantly preventive to the occurrence of POAF in patients with vitamin D insufficiency and deficiency who underwent CABG surgery.

Simple Amiodarone Protocol Reduces Postoperative Atrial Fibrillation

Background

Incorporating amiodarone into an existing postoperative atrial fibrillation (AF) prevention pathway may reduce postoperative AF and length of stay (LOS).

Methods

From July 2002 through December 2002, 476 consecutive cardiac surgical patients were managed with an AF prevention protocol using aggressive potassium replacement, intraoperative/ postoperative magnesium supplementation, and postoperative resumption of β-blockers. From January 2003 through June 2003, 592 additional patients were subjected to the same protocol except amiodarone was initiated intraoperatively (150 mg intravenously) and continued postoperatively until discharge (200 mg orally three times daily). Incidence of AF, postoperative LOS, and AF risk factors were collected prospectively and compared using regression models with propensity scores to adjust for dissimilarities between groups.

Results

Incorporating amiodarone into an existing AF protocol resulted in a 45% reduction in postoperative AF (29% [136/476] versus 16% [94/592], P < 0.0001). After adjustment for covariates and propensity score, the relative risk reduction with amiodarone in this protocol remained significant (P = 0.001, RR 0.65, 95% CI 0.5–0.8). Multivariate risks for postoperative AF included no amiodarone (P = 0.0001), age (P < 0.0001), ejection fraction <40% (P = 0.0005), ventilator support >24 hours (P = 0.002), no postoperative β-blocker (P = 0.002), and mitral valve procedure (P = 0.03). When postoperative AF did occur, risk adjusted LOS was less in patients on the amiodarone protocol (mean 9.4 days versus 13.1 days, P = 0.06). Readmission after discharge for any reason (10% [49/476] versus 8% [45/592], P = 0.1) or for AF (1.1% [5/476] versus 0.7% [4/592], P = 0.5) was similar between groups.

Conclusion

Amiodarone initiated intraoperatively followed by oral dosing significantly reduces postoperative AF and tends to reduce LOS if AF occurs.

Colchicine for prevention of post-cardiac procedure atrial fibrillation: Meta-analysis of randomized controlled trials

BACKGROUND

Development of atrial fibrillation after certain cardiac procedures is a common medical problem. The inflammatory process plays an important role in the pathogenesis of post-cardiac procedure atrial fibrillation (PCP-AF). Colchicine, a potent anti-inflammatory agent, has been used in several studies to reduce the risk of PCP-AF. This meta-analysis of randomized controlled trials (RCTs) was conducted to assess the efficacy of colchicine in prevention of PC-PAF.

METHODS

We searched PubMed, EMBASE, Web of Science, Cochrane Library database and Google Scholar for RCTs, using terms "Atrial fibrillation, atrial, or fibrillation and colchicine". The primary end-point was the occurrence of AF post cardiac procedure, which includes cardiac surgery or pulmonary vein isolation. The safety end point was the occurrence of any side effects. Estimated odds ratios (OR) and 95% confidence intervals (CI) were evaluated.

RESULTS

A total of six RCTs were included in this meta-analysis, enrolling a total of 1257 patients. Colchicine significantly reduced the odds of PCP-AF (OR 0.52; 95% CI, 0.40-0.68, P<0.001, I²=0%). However, occurrence of side effects was significantly higher with colchicine when compared to placebo (OR 2.10; 95% CI, 1.34-3.30, P<0.001, I²=0%). The number needed to treat is 7 and the number needed to harm is 11.2. The proportion of patients discontinuing treatment was 16%.

CONCLUSION

This meta-analysis shows that colchicine is an effective drug for prevention of PCP-AF. Colchicine could be considered as a prophylaxis to reduce PCP-AF, with some risk of treatment discontinuation due to the poor gastrointestinal tolerance (diarrhea).

Epidemiology of new-onset atrial fibrillation following coronary artery bypass graft surgery

OBJECTIVES

Postoperative atrial fibrillation (AF) following coronary artery bypass graft surgery (CABG) is significantly associated with reduced survival, but poor characterisation and inconsistent definitions present barriers to developing effective prophylaxis and management. We sought to address this knowledge gap.

METHODS

From 2002 to 2010, 11 239 consecutive patients without AF underwent isolated CABG at five sites. Clinical data collected for the Society of Thoracic Surgeons (STS) Database were augmented with details on AF detected via continuous in-hospital ECG/telemetry monitoring to assess new-onset post-CABG AF (adjusted for STS risk of mortality); time to first AF; durations of first and longest AF episodes; total in-hospital time in AF; number of in-hospital AF episodes; operative mortality; stroke; discharge in AF; and length of stay (LOS).

RESULTS

Unadjusted incidence of new-onset post-CABG AF was 29.5%. Risk-adjusted incidence was 33.1% and varied little over time (P=0.139). Among 3312 patients with post-CABG AF, adjusted median time to first AF was 52 (IQR: 48-55) hours; mean (SD) duration of first and longest events were 7.2 (5.3,9.1) and 13.1 (10.4,15.9) hours, respectively, and adjusted median total time in AF was 22 (IQR: 18-26) hours. Adjusted rates of operative mortality, stroke and discharge in AF did not vary significantly over time (P=0.156, P=0.965 and P=0.347, respectively). LOS varied (P=0.035), but in no discernible pattern.

CONCLUSIONS

Each year, ~800 000 people undergo CABG worldwide; >264 000 will develop post-CABG AF. Onset is typically 2-3 days post-CABG and episodes last, on average, several hours. Effective prophylaxis and management is urgently needed to reduce associated risks of adverse outcomes.

A new predictor of atrial fibrillation after coronary artery bypass graft surgery: HATCH score

The aim of this study was to investigate the association between HATCH score and atrial fibrillation (AF) after coronary artery bypass graft (CABG) surgery. 369 patients (103 patients with AF and 266 patients without AF) undergoing isolated CABG surgery were analyzed. Complete medical records were retrospectively collected to investigate HATCH score. The median age of patients with AF was significantly higher than the median age of non-AF group (60.8±10.0 years vs 67.8±9.5 years, P<0.001). HATCH score was significantly higher in patients who developed AF after CABG surgery than the non-AF group (P=0.017). Multivariate logistic regression analysis showed that HATCH score (OR 1.334; 95% CI 1.022 to 1.741, P=0.034) was an independent predictor of AF after CABG surgery. Receiver operating characteristic curve analysis showed that the cut-off point of HATCH score related to predict AF was >1 (two or more), with a sensitivity of 42% and specificity of 70%. Patients with elevated preoperative HATCH score may have higher risk for AF after CABG surgery.

Randomized Trial of Carnitine for the Prevention of Perioperative Atrial Fibrillation

Atrial fibrillation (AF) is one of the most common complications in patients who undergo coronary artery bypass graft surgery (CABG). The aim of this study was to evaluate the effect of L-carnitine administration on postoperative AF and the levels of C-reactive protein (CRP) following CABG. The effects of L-carnitine on the incidence of acute kidney injury after CABG were also assessed. One hundred thirty-four patients undergoing elective CABG, without a history of AF or previous L-carnitine treatment, were randomly assigned to an L-carnitine group (3000 mg/d L-carnitine) or a control group. CRP levels, as a biomarker of inflammation, were assessed in all the patients before surgery as baseline levels and 48 hours postoperatively. Neutrophil gelatinase-associated lipocalin, as a kidney biomarker, was also measured in the patients before surgery and 2 hours thereafter. The incidence of AF was 13.4% in our population. The incidence of AF was decreased in the L-carnitine group (7.5% in the L-carnitine group vs 19.4% in the control group; P = 0.043) and the postoperative CRP level (8.79 ± 6.9 in the L-carnitine group, and 10.83 ± 5.7 in the control group; P = 0.021). The postoperative neutrophil gelatinase-associated lipocalin concentration demonstrated no significant rise after surgery compared with the preoperative concentration (72.54 ± 20.30 in the L-carnitine group vs 67.68 ± 22.71 in the placebo group; P = 0.19). Our study showed that L-carnitine administration before CABG might inhibit and reduce the incidence of AF after CABG. It seems that a rise in the CRP level, as an inflammation marker, may be associated with the incidence of AF. Inflammation as measured by CRP was also reduced in the carnitine group, compared with the control group.

Pharmacogenomics in Anesthesia

A significant number of commonly administered medications in anesthesia show wide clinical interpatient variability. Some of these include neuromuscular blockers, opioids, local anesthetics, and inhalation anesthetics. Individual genetic makeup may account for and predict cardiovascular outcomes after cardiac surgery. These interactions can manifest at any point in the perioperative period and may also only affect a specific system. A better understanding of pharmacogenomics will allow for more individually tailored anesthetics and may ultimately lead to better outcomes, decreased hospital stays, and improved patient satisfaction.

Cardiac Arrhythmia After Open Thoracoabdominal Aortic Aneurysm Repair

BACKGROUND

Cardiac arrhythmias commonly arise after cardiac surgery and are associated with poor prognosis. In thoracoabdominal aortic aneurysm (TAAA) repair, these complications are poorly understood. We assessed characteristics, incidence, outcomes, and potential predictors of postoperative arrhythmia (PA) after open TAAA repair.

METHODS

From 2010 to 2014, 403 consecutive open TAAA replacement operations were performed in patients without preoperative cardiac rhythm abnormalities at a single tertiary center. We compared preoperative characteristics, operative factors, and postoperative outcomes in patients with and without PA, and we used multivariable logistic regression to identify predictors of PA.

RESULTS

PA occurred after 107 (26.5%) procedures. Atrial fibrillation (23%) was the most common type of PA. Length of hospital stay and operative mortality were greater in patients with PA than in patients without it (p < 0.01 for both). Kaplan-Meier cumulative survival for patients with PA was lower than for patients without PA: 69.2% ± 4.6% versus 88.3% ± 2.0% at 1 year and 59.0% ± 5.3% versus 85.0% ± 2.3% at 3 years (p < 0.001 for both). The odds of PA increased with advancing age (1.07 per year; p < 0.001). In addition, the odds of developing PA were higher in patients who received visceral perfusion (odds ratio, 2.58; p = 0.001) and were lower in patients who underwent extent IV repair (odds ratio, 0.44; p = 0.01).

CONCLUSIONS

Postoperative cardiac arrhythmia was common after open TAAA repair. Older patients and patients who underwent visceral perfusion were more likely to develop PA. Cardiac arrhythmia after TAAA repair was associated with prolonged hospital stay, higher early mortality, and lower midterm survival.

Incidence, Predictors, and Outcomes of Early Atrial Arrhythmias After Lung Transplant: A Systematic Review and Meta-Analysis

OBJECTIVES

This study sought to determine the incidence, predictors, and prognostic implications of early post-lung transplant atrial arrhythmias (AAs).

BACKGROUND

Although frequently encountered, the prognostic implications of early AAs after lung transplant remain uncertain.

METHODS

A systematic review of MEDLINE and the Cochrane Library was conducted for all studies that reported early post-lung transplant AAs. Random-effects DerSimonian-Laird risk ratios (RRs) were calculated for categorical variables and standardized mean difference (SMD) for continuous variables.

RESULTS

A total of 12 studies with 3,203 patients (mean age 57 ± 3 years; 52% males) were included. The incidence of early post-lung transplant AAs during hospitalization was 26.6% at mean follow-up duration of 6.7 days. Predictors of post-lung transplant AAs included advanced age (SMD: 0.50; 95% confidence interval [CI]: 0.35 to 0.64), male gender (RR: 1.37; 95% CI: 1.28 to 1.47), history of smoking (RR: 1.23; 95% CI: 1.05 to 1.46), hypertension (RR: 1.35; 95% CI: 1.13 to 1.59), hyperlipidemia (RR: 1.39; 95% CI: 1.18 to 1.63), coronary artery disease (RR: 1.40; 95% CI: 1.12 to 1.7), left atrial diameter (SMD: 0.25; 95% CI: 0.07 to 0.44), and restrictive lung disease (RR: 1.34; 95% CI: 1.13 to 1.59). Post-lung transplant AAs were associated with increased all-cause mortality (adjusted RR: 1.63; 95% CI: 1.22 to 2.19) at mean follow-up of 27.8 months and length of hospital stay (36.5 ± 16.5 days vs. 26.1 ± 14.3 days; p < 0.001).

CONCLUSIONS

Early AAs post-lung transplant are associated with increased mortality and length of hospital stay. Advanced age, male sex, smoking, hypertension, hyperlipidemia, coronary artery disease, increased left atrial diameter, and restrictive lung disease are independent predictors of early AAs in post-lung transplant patients.

Should pre-operative left atrial volume receive more consideration in patients with degenerative mitral valve disease undergoing mitral valve surgery?

BACKGROUND

Severe primary mitral regurgitation (MR) carries a significant incidence of mortality and morbidity. Though a number of prognostic factors have been identified, the best timing for mitral valve repair is still debated. We assessed the role of Left Atrial Volume Indexed (LAVI) as predictor of adverse events after mitral valve surgery.

METHODS

134 patients with severe MR were studied with a follow-up of 42±16months. Endpoints were Post-Operative Atrial Fibrillation (POAF), atrial and ventricular remodeling (LARR/LVRR) and correlation with outcome. POAF was defined as AF occurring within 2weeks and late AF (LAF) more than 2weeks after surgery. LARR was defined as LAVI reduction ≥15% and LVRR as any reduction of ventricular mass after surgery.

RESULTS

Forty-one patients experienced POAF, 26 had LAF. Pre-operative LAVI was an independent risk factor for POAF (OR 1.03, CI [1.00-1.06], p=0.01), LAF (OR 1.03, CI [1.00-1.06], p=0.02), LARR and LVRR (OR 1.04, CI [1.01-1.07], p=0.002, respectively). LARR was found in 75 patients, while LVRR in 111. Patients with heart remodeling had less incidence of LAF and cardiac adverse events, better diastolic function and improved their NYHA class after surgery.

CONCLUSIONS

LAVI should be given more weight into decision making for patients with MR as it predicts POAF and LAF and reverse atrial and ventricular remodeling, both associated to long-term outcome.

Incidence, Predictors, and Impact of Postoperative Atrial Fibrillation after Coronary Artery Bypass Grafting in Military Veterans

Little is known about the frequency and clinical implications of postoperative atrial fibrillation in military veterans who undergo coronary artery bypass grafting (CABG). We examined long-term survival data, clinical outcomes, and associated risk factors in this population. We retrospectively reviewed baseline, intraoperative, and postoperative data from 1,248 consecutive patients with similar baseline risk profiles who underwent primary isolated CABG at a Veterans Affairs hospital from October 2006 through March 2013. Multivariable logistic regression identified predictors of postoperative atrial fibrillation. Kaplan-Meier analysis was used to evaluate long-term survival (the primary outcome measure), morbidity, and length of hospital stay. Postoperative atrial fibrillation occurred in 215 patients (17.2%). Independent predictors of this sequela were age ≥65 years (odds ratios [95% confidence intervals], 1.7 [1.3-2.4] for patients of age 65-75 yr and 2.6 [1.4-4.8] for patients >75 yr) and body mass index ≥30 kg/m² (2.0 [1.2-3.2]). Length of stay was longer for patients with postoperative atrial fibrillation than for those without (12.7 ± 6.6 vs 10.3 ± 8.9 d; P ≤0.0001), and the respective 30-day mortality rate was higher (1.9% vs 0.4%; P=0.014). Seven-year survival rates did not differ significantly. Older and obese patients are particularly at risk of postoperative atrial fibrillation after CABG. Patients who develop the sequela have longer hospital stays than, but similar long-term survival rates to, patients who do not.

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.

De novo atrial fibrillation post cardiac surgery: the Durban experience

Atrial fibrillation (AF) is the most common complication post cardiac surgery and results in elevated morbidity and mortality rates and healthcare costs. A pilot, retrospective study of the medical records of all adult patients developing de novo AF post surgery was undertaken at the cardiac surgical unit in Durban between 2009 and 2012. We aimed to describe the local experience of AF with a view to suggesting an adapted local treatment policy in relation to previously published data. Fifty-nine patients developed AF during the study period. AF occurred predominantly three or more days post surgery. Thirty-five patients required cardioversion and amiodarone to restore sinus rhythm. Return to the general ward (RGW) was 4.6 days longer than the institutional norm. Liberal peri-operative β-blocker and statin use is currently preferred to a formal prophylaxis strategy. Randomised, controlled trials are required to evaluate measures curbing prolonged length of stay and morbidity burdens imposed by AF on the local resource-constrained environment.

Diastolic function and new-onset atrial fibrillation following cardiac surgery

Background:

Numerous studies have reported predictors of new-onset postoperative atrial fibrillation (POAF) following cardiac surgery, which is associated with increased length of stay, cost of care, morbidity, and mortality. The purpose of this study was to examine the association between preoperative diastolic function and occurrence of new-onset POAF in patients undergoing a variety of cardiac surgeries at a single institution.

Methods:

Using data from a prospective study from November 2007 to January 2010, a retrospective review was conducted. The diastolic function of each patient was determined from preoperative transthoracic echocardiograms. Occurrence of new-onset POAF was prospectively noted for each patient in the original study. Demographic and operative characteristics of the study population were analyzed to determine predictors of POAF.

Results:

Of 223 patients, 91 (40.8%) experienced new-onset POAF. Univariate predictors of POAF included increasing age, male gender, operations involving mitral valve repair/replacement, nonsmoking, hypertension, increased intraoperative pulmonary artery pressure, grade I diastolic dysfunction, abnormal diastolic function of any grade, decreased medial e’, elevated medial E/e’, and increased left atrial volume. Multivariate predictors of POAF included increasing age, increased left atrial volume, and elevated initial intraoperative pulmonary artery pressure. Even after exclusion of patients with hypertrophic obstructive cardiomyopathy or those undergoing mitral valve operations, diastolic dysfunction was not a multivariate predictor of POAF.

Conclusions:

In the patient population studied here, preoperative diastolic dysfunction was not predictive of POAF. In addition to increasing age, initial intraoperative pulmonary artery systolic pressure and left atrial volume were both significant multivariate predictors of POAF.

Preventive strategies for atrial fibrillation after cardiac surgery in Nordic countries

BACKGROUND AND AIMS

Atrial fibrillation is a common arrhythmia after cardiac surgery. It increases morbidity, length of hospital stay, and costs of operative treatment. Beta-blockers, sotalol, amiodarone, corticosteroids, and biatrial pacing have been shown to be efficient in the prevention of postoperative atrial fibrillation. The aim of this study was to find out how widely different prophylactic strategies for postoperative atrial fibrillation are used in Scandinavian countries.

MATERIAL AND METHODS

An online link for a questionnaire was emailed to (214) cardiac surgeons in Finland, Sweden, Norway, Denmark, and Estonia to assess the use of prophylactic methods for postoperative atrial fibrillation.

RESULTS

A total of 97 surgeons responded to the survey. Oral beta-blockers were routinely used for atrial fibrillation prophylaxis by 62% of responders. The main reasons for nonuse of beta-blockers were that responders were unconvinced of the evidence of benefit or they preferred some alternative prophylaxis. Intravenous beta-blockers were used frequently by 6% of responders. Amiodarone was used for prophylaxis by 18% of responders. Nonusers were unconvinced of its efficacy, were afraid of its complications, or found its use too cumbersome. Other prophylactic atrial fibrillation strategies that were used are as follows: sotalol by 2%, magnesium by 17%, corticosteroids by 1%, and atrial pacing by 11% of respondents.

CONCLUSIONS

There is still widely varying implementation of strategies for atrial fibrillation prophylaxis among Scandinavian cardiac surgeons. Lack of confidence in the efficacy of these approaches is the main rationale for nonimplementation.

Ivabradine Versus Beta-Blockers in Patients with Conduction Abnormalities or Left Ventricular Dysfunction Undergoing Cardiac Surgery

INTRODUCTION

In patients with conduction abnormalities or left ventricle (LV) dysfunction the use of β-blockers for post cardiac surgery rhythm control is difficult and controversial, with a paucity of information about other drugs such ivabradine used postoperatively. The objective of this study was to compare the efficacy and safety of ivabradine versus metoprolol used perioperatively in cardiac surgery patients with conduction abnormalities or LV systolic dysfunction.

METHODS

This was an open-label, randomized clinical trial enrolling 527 patients with conduction abnormalities or LV systolic dysfunction undergoing coronary artery bypass grafting or valvular replacement, randomized to take ivabradine or metoprolol, or metoprolol plus ivabradine. The primary endpoints were the composites of 30-day mortality, in-hospital atrial fibrillation (AF), in-hospital three-degree atrioventricular block and need for pacing, in-hospital worsening heart failure (HF; safety endpoints), duration of hospital stay and immobilization and the above endpoint plus in-hospital bradycardia, gastrointestinal symptoms, sleep disturbances, cold extremities (efficacy plus safety endpoint).

RESULTS

Heart rate reduction and prevention of postoperative AF or tachyarrhythmia with combined therapy was more effective than with metoprolol or ivabradine alone during the immediate postoperative management of cardiac surgery patients. In the Ivabradine group, the frequency of early postoperative pacing and HF worsening was smaller than in the Metoprolol group and in combined therapy group. The frequency of primary combined endpoint was lower in the combined Ivabradine + Metoprolol group compared with the monotherapy groups.

CONCLUSION

Considering efficacy and safety, the cardiac rhythm reduction after open heart surgery in patients with conduction abnormalities or LV dysfunction with ivabradine plus metoprolol emerged as the best treatment in this trial.

Transient post-operative atrial fibrillation predicts short and long term adverse events following CABG

OBJECTIVE

To assess the relationship between the development of transient post-operative atrial fibrillation (TPOAF) following coronary artery bypass graft (CABG) surgery and risk of long-term mortality.

BACKGROUND

Atrial fibrillation (AF) following CABG is common and associated with increased morbidity and mortality in the perioperative period. However the impact of TPOAF and its management on long-term morbidity and mortality in patients undergoing first time, isolated CABG surgery remains unclear.

METHODS

The Cleveland Clinic Cardiovascular Information Registry was used to identify 5,205 consecutive patients who underwent CABG between January 1993 and December 2005. Patients with TPOAF (n=1,490) were compared to those without post-operative AF (n=3,645) for the endpoints of death, myocardial infarction (MI), or stroke at 1 year.

RESULTS

Overall rates of 1-year mortality, MI and stroke were 3.7%, 0.8%, and 2.6%, respectively. Patients with TPOAF had an increased risk of death at 1 year as compared to patients without POAF (6.4% vs. 2.7%; P<0.001), but there was not an increased risk of stroke or MI. Multivariate analysis identified TPOAF as an independent predictor of death at 1 year (HR 1.89, 95% CI, 1.42-2.53; P<0.001). After propensity matching, patients who developed TPOAF experienced a significantly increased risk of death compared with those without TPOAF (HR 1.96, 95% CI, 1.34-2.86; P<0.001).

CONCLUSIONS

In patients undergoing first time, isolated CABG, the presence of TPOAF identifies a subgroup of patients at increased risk for all-cause mortality. Future prospective studies to determine potential beneficial interventions in this large population are warranted.

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.

Obstructive sleep apnea as a predictor of atrial fibrillation after coronary artery bypass grafting: a systematic review and meta-analysis

BACKGROUND

Post-coronary artery bypass grafting atrial fibrillation (PCAF) is associated with increased morbidity, mortality, and system costs. Few studies have explored obstructive sleep apnea (OSA) as a risk factor for PCAF. We aimed to systematically review and synthesize the evidence associating OSA with PCAF.

METHODS

We conducted a search of MEDLINE, EMBASE, Google Scholar, and Web of Science, as well as abstracts, conference proceedings, and reference lists until June 2014. Eligible studies were in English, were conducted in humans, and assessed OSA with polysomnography (PSG) or a validated questionnaire. Two reviewers independently selected studies, with disagreement resolved by consensus. Piloted forms were used to extract data and assess risk of bias.

RESULTS

Five prospective cohort studies were included (n = 642). There was agreement in study selection (κ statistic, 0.89; 95% confidence interval [CI], 0.75-1.00). OSA was associated with a higher risk of PCAF (odds ratio [OR], 1.86; 95% CI 1.24-2.80; P = 0.003; I(2) = 35%). We conducted 3 subgroup analyses. The associations increased for data that used PSG to assess OSA (OR, 2.34; 95% CI, 1.48-3.70), when severe OSA was included from 1 study (OR, 2.59; 95% CI, 1.63-4.11), and when adjusted analyses were pooled (OR, 2.38; 95% CI, 1.57-3.62; P < 0.001 in all), with no heterogeneity detected in any subgroup analysis (I(2) < 0.01% in all).

CONCLUSIONS

OSA was shown to be a strong predictor of PCAF.

Postoperative atrial fibrillation: incidence, mechanisms, and clinical correlates

Atrial fibrillation is the most commonly encountered arrhythmia after cardiac surgery. Although usually self-limiting, it represents an important predictor of increased patient morbidity, mortality, and health care costs. Numerous studies have attempted to determine the underlying mechanisms of postoperative atrial fibrillation (POAF) with varied success. A multifactorial pathophysiology is hypothesized, with inflammation and postoperative β-adrenergic activation recognized as important contributing factors. The management of POAF is complicated by a paucity of data relating to the outcomes of different therapeutic interventions in this population. This article reviews the literature on epidemiology, mechanisms, and risk factors of POAF, with a subsequent focus on the therapeutic interventions and guidelines regarding management.

Effect of preoperative obstructive sleep apnea on the frequency of atrial fibrillation after coronary artery bypass grafting

Patients with obstructive sleep apnea (OSA) have intermittent hypoxia leading to atrial remodeling and this has been associated with the development of atrial fibrillation (AF). Postoperative AF is a common complication of coronary artery bypass grafting (CABG). The aim of this prospective study was to determine whether the presence of OSA predicts the occurrence of post-CABG AF (PCAF). This was a prospective single-center study. Patients undergoing elective CABG were evaluated and categorized as confirmed, high-risk, or low-risk OSA according to a modified Berlin questionnaire. PCAF was evaluated by 24-hour cardiac monitoring strip or 12-lead electrocardiography during the postoperative period, and validated by an electrophysiologist. We included 277 patients. OSA prevalence was 47.7%, with body mass index (31.0 vs 26.9 kg/m(2), p ≤0.001), advanced age (63.7 vs 66.4 years, p = 0.031), hypertension (78.0% vs 64.8%, p = 0.015), and diabetes (45.5% vs 28.3%, p = 0.003) more prevalent in the OSA group. PCAF was found to occur in 37.2% of all patients and OSA was found to be a strong predictor of PCAF (45.5% vs 29.7%, p = 0.007). PCAF was also associated with continuous positive airway pressure use (12.6% vs 5.2%, p = 0.027). Increased length of stay was associated with PCAF (6.5 vs 5.3 days, p = 0.006), as was longer time from surgery to occurrence of PCAF (p = 0.001). In conclusion, OSA was found to be a strong predictor of PCAF, which in turn was found to be associated with increased length of stay.

Patients with atrial fibrillation undergoing total joint arthroplasty increase hospital burden

BACKGROUND

More than 3 million people in the United States have atrial fibrillation, most of whom are being managed with anticoagulation therapy for life. The goal of the present study was to examine the effect of chronic anticoagulation therapy on patients with atrial fibrillation who undergo total joint arthroplasty.

METHODS

We retrospectively reviewed all patients undergoing aseptic primary or revision total joint arthroplasty at our facility from March 2007 to August 2011. One hundred and sixty-one patients with atrial fibrillation (Group A) were compared with 161 matched controls (Group B). A total of 112 hips and 210 knees underwent 239 primary arthroplasties and eighty-three revisions. The groups were compared with use of conditional logistic regression (with matching on the basis of the involved joint [hip or knee], type of procedure [revision or primary], age, and sex) with regard to the length of hospital stay, postoperative hemoglobin levels, transfusion requirements, and readmissions.

RESULTS

The preoperative length of stay (1.7 versus 0.2 days; p < 0.0001), postoperative length of stay (4.6 versus 3.2 days; p = 0.0002), and total length of stay (6.3 versus 3.4 days; p < 0.0001) were significantly longer for patients with atrial fibrillation (Group A). Hemoglobin levels were lower (but not significantly so) for Group A at baseline (13.1 versus 13.8 mg/dL), on Postoperative Day 2 (10.1 versus 10.6 mg/dL), on Postoperative Day 3 (9.8 versus 10.2 mg/dL), on Postoperative Day 4 (9.6 versus 10.1 mg/dL), on Postoperative Day 5 (9.7 versus 9.9 mg/dL), and at discharge (9.9 versus 10.3 mg/dL). Group A had a significantly higher prevalence of blood transfusion (15.5% versus 3.7%; p = 0.0005) and periprosthetic joint infection (5.6% versus 0.62%; p = 0.0196). A diagnosis of atrial fibrillation (odds ratio, 4.09; 95% confidence interval, 2.05 to 8.18; p < 0.0001) significantly increased the odds of total joint arthroplasty complication and the need for hospital readmission.

CONCLUSIONS

Patients with preoperative atrial fibrillation undergoing total joint arthroplasty had an increased length of hospital stay, increased transfusion requirements, and an increased risk of periprosthetic joint infection and unplanned hospital readmission.

Left atrial longitudinal strain parameters predict postoperative persistent atrial fibrillation following mitral valve surgery: a speckle tracking echocardiography study

Postoperative atrial fibrillation (POAF) is common after cardiac surgery and is associated with increased morbidity, mortality, and prolonged hospital stay. Speckle tracking echocardiography (STE) has been applied recently for evaluation of LA function. The purpose of this study was to examine whether left atrial longitudinal strain measured by STE is a predictor for the development of POAF following mitral valve surgery for severe mitral regurgitation. We studied 53 patients undergoing mitral valve surgery in sinus rhythm at the time of surgery. Echocardiography with evaluation of LA strain by STE was performed. Detection of POAF was based on documentation of AF episodes by continuous telemetry throughout hospitalization. Patients who did not develop POAF were taken as group 1 and those who had POAF constituted group 2. The echocardiographic and clinical predictors of POAF were investigated. POAF occurred in 28.3% of subjects. Mean age, LAVi and BNP were found higher in group 2 while peak atrial longitudinal strain (PALS) (13.9 ± 3.8% vs. 24.8 ± 7.3%; P < 0.001), peak atrial contraction strain (PACS) (7.6 ± 1.95% vs. 11.3 ± 3.5%; P < 0.001) were significantly lower. By multivariate logistic regression analysis, PALS and LAVi were independent predictor of POAF development. LA longitudinal strain was found to predict POAF in patients undergoing mitral valve surgery. It could be used to better identify patients at greater risk of developing POAF, and thus to guide in risk stratification and to take appropriate intensive prophylactic therapy.

A comparative study on the effect of amiodarone and metaprolol for prevention of arrythmias after open heart surgery

OBJECTIVES

The aim of this study was to compare the effect of amiodarone and metaprolol in prevention of atrial fibrillation in patients, following open heart surgery.

METHODS

This prospective study was carried out between May 2008 to Nov. 2010, and comprised a total of 50 patients with normal preoperative sinus rhythm undergoing open heart surgery using cardio pulmonary bypass.

RESULTS

Mean age of patients was 47+2.7 years, of which 60% who developed atrial fibrillation aged from 51 to 60 years. Most patients (62%) were in NYHA Class III. Patients who received amiodarone showed significant improvement in LVEF compared to those treated with Metaprolol. Amiodarone treated group exhibited lesser incidence and short-lasting atrial fibrillation, lower ventricular rate, shorter hospitalization, and lesser cost of care than those in metaprolol group.

CONCLUSIONS

The present study showed that amiodarone was more efficient in controlling post-operative atrial fibrillation as compared to metaprolol. However, a larger randomized controlled trial is needed to corroborate the result of this study.

Drug-induced atrial fibrillation

Atrial fibrillation (AF) is a common cardiac arrhythmia that is associated with severe consequences, including symptoms, haemodynamic instability, increased cardiovascular mortality and stroke. While other arrhythmias such as torsades de pointes and sinus bradycardia are more typically thought of as drug induced, AF may also be precipitated by drug therapy, although ascribing causality to drug-associated AF is more difficult than with other drug-induced arrhythmias. Drug-induced AF is more likely to occur in patients with risk factors and co-morbidities that commonly co-exist with AF, such as advanced age, alcohol consumption, family history of AF, hypertension, thyroid dysfunction, sleep apnoea and heart disease. New-onset AF has been associated with cardiovascular drugs such as adenosine, dobutamine and milrinone. In addition, medications such as corticosteroids, ondansetron and antineoplastic agents such as paclitaxel, mitoxantrone and doxorubicin have been reported to induce AF. Whether bisphosphonate drugs are associated with new-onset AF remains controversial and requires further study. The potential contribution of specific drug therapy should be considered when patients present with new-onset AF.

Do Statins Reduce Atrial Fibrillation After Coronary Artery Bypass Grafting?

Background: Atrial Fibrillation (AF) is a common postoperative complication after coronary artery bypass grafting. There is contradictory evidence as to whether pre-operative statin use lowers the incidence of postoperative AF. This study aimed to assess whether pre operative statin therapy prevents the post-operative AF. Methods: In this retrospective cohort study we used a propensity score-matching analysis to evaluate the effect of preoperative treatment with statins on postoperative atrial fibrillation. There were 427 matched pairs of patients. Primary outcome was the incidence of postoperative AF. Secondary outcomes were 30 day mortality, stroke, myocardial infarction and length of hospital stay. Results: The incidence of postoperative AF was not different in the statin users compared with the nonusers (123, 28.1%, versus 127, 29.7%, respectively; p = 0.764). The 30 day mortality (6, 1.4%, versus 8, 1.9%; p = 0.590), stroke (10, 2.3%, versus 8, 1.9%; p = 0.634), myocardial infarction (2, 0.5%, versus 0, 0.0%; p = 0.499) and length of hospital stay in days (11.8 ± 9.0, versus 11.9 ± 9.3; p = 0.544) did not differ significantly between the two groups. Conclusions: In a propensity-matched cohort of patients undergoing coronary bypass surgery, we could not demonstrate that preoperative statins were protective for the development of post operative atrial fibrillation.

Left Atrial Volume and Post-Operative Atrial Fibrillation after Aortic Valve Replacement

Post-operative atrial fibrillation (POAF) after valve surgery is associated with increased morbidity and mortality. Risk factors identified in the past to predict POAF are of moderate accuracy. We performed a retrospective analysis of 139 patients undergoing aortic valve replacement for aortic stenosis. Post-operative AF occurred in 44% of the patients. In multivariate analysis only left atrial volume (LAV) index was a predictor of POAF. A LAV index of >46 cc/m2 predicted POAF with a sensitivity and specificity of 92% and 77%. We propose that LAV index can be used preoperatively to identify patients at risk for POAF to target preventive interventions. Background: Post-operative atrial fibrillation (POAF) is common after valve surgery and is associated with increased morbidity and mortality. Many of the previously identified predictors of POAF are of moderate accuracy. Left atrial volume (LAV) index has been proposed in the past as a predictor of POAF in patients undergoing cardiac surgery. In patients with aortic stenosis (AS), increased LAV is a marker of severity of stenosis. Hypothesis: Left atrial volume index is a very good predictor of POAF in patients undergoing aortic valve replacement (AVR) for AS. Methods: We performed a retrospective analysis of 139 consecutive patients with no previous atrial fibrillation (AF) undergoing AVR for AS in our center. Results: Post-operative AF occurred in 44% of patients. Patients with POAF had a longer hospital stay compared to patients without (12 vs 8 days; p < 0.001). In univariate analysis, age (p = 0.046), aortic valve area (p = 0.005) and LAV index (p < 0.001) were significant predictors of POAF. In multivariate analysis only LAV index (R2= 0.58; p < 0.001) predicted POAF. A LAV index > 46ml/m2 predicted POAF with a sensitivity and specificity of 92% and 77% respectively. Moreover, there was a significant increase in the incidence of POAF with increasing quartiles of LAV index, supporting causality. Conclusion: Left atrial volume index is an excellent predictor of POAF in patients undergoing AVR for AS. It can be used for selecting patients who are at a high risk for developing POAF to target preventive interventions.

Factors associated with long hospital length of stay in patients receiving warfarin after cardiac surgery

BACKGROUND

Patients receiving warfarin therapy after coronary artery bypass graft (CABG) or valve surgery have longer length of stay (LOS) than those not receiving warfarin therapy. Longer LOS increases patient costs, postdischarge recovery time, and rehabilitation. It is important to identify variables of longer postoperative LOS in this patient population so that the healthcare team can develop and facilitate interventions to minimize length of hospitalization.

METHODS

Using a hospital registry and medical record review of cases completed in 2004, data from cardiac surgery patients having CABG and/or valve procedures and given warfarin postoperatively were analyzed based on short (<7 days, CABG; 9 days, valve procedure) and long (> or =7 days, CABG; > or =9 days, valve procedure) postoperative LOS. By groups, significant associations were assessed using chi or Fisher exact test for categorical variables and Wilcoxon 2-sample test or Student t test for continuous variables.

RESULTS

In 82 patients (33 CABG and 49 valve +/- CABG) who were given warfarin, most demographic, medical history, postoperative complications, and use of cardiac drugs did not predict longer LOS. Longer postoperative LOS was associated with being older (mean age, 73.5 vs 68.5 years), being not married, having postoperative respiratory insufficiency, and receiving more red blood cell transfusions, all P < .05; and having more healthcare consultations, longer critical care stay, and longer time between surgery date and start of warfarin; all P < .001.

CONCLUSIONS

Variables associated with longer LOS were nonmodifiable by nursing services and were difficult to assess preoperatively. They primarily involved intraoperative or postoperative bleeding that led to red blood cell infusion and longer critical care stays that delayed warfarin initiation. However, older age and marital status are nursing targets because they may be associated with social isolation and other psychosocial issues. Transition of care programs can be developed to promote earlier discharge.

Hemofiltration during cardiopulmonary bypass does not decrease the incidence of atrial fibrillation after cardiac surgery

BACKGROUND

Atrial fibrillation (AF) occurs in 20%-50% of patients after cardiac surgery and is associated with increased morbidity and mortality. Corticosteroids are reported to decrease the incidence of postoperative AF, presumably by attenuating inflammation caused by surgery and cardiopulmonary bypass (CPB). We hypothesized that hemofiltration during CPB, which may attenuate inflammation, might decrease the incidence of AF after cardiac surgery.

METHODS

This was a retrospective review of patients previously enrolled in a double-blind, placebo-controlled trial evaluating the effects of perioperative steroid therapy and hemofiltration during CPB on duration of postoperative mechanical ventilation. In that study, 192 patients undergoing cardiac surgery were randomized to 1 of 3 groups: controls (placebo), hemofiltration during CPB, or perioperative steroid therapy. Patient records were reviewed to determine the incidence of new onset AF defined as any electrocardiogram evidence of AF or AF diagnosed by the patients' clinicians.

RESULTS

Of the 192 enrolled patients, 3 were excluded for protocol violations and 4 were excluded for history of chronic AF. Data from 185 patients from the original study were available for review. Sixty patients (32%) had new onset AF after cardiac surgery. There was no difference among groups in the incidence of AF (control group, 21%; steroid group, 41%; hemofiltration group, 36%; P = 0.057 among groups). The only risk factor for the development of AF was age (mean age of patients with AF, 65.4 +/- 10.1 yr vs patients without AF, 61.4 +/- 11.5 yr; P = 0.024). When age, procedure type, and presence or absence of chronic obstructive pulmonary disease were controlled for in multivariate analysis, the difference among study groups remained nonsignificant (P = 0.108).

CONCLUSIONS

Perioperative corticosteroids or the use of hemofiltration during CPB did not decrease the incidence of AF after cardiac surgery. Further studies evaluating the efficacy and safety of perioperative corticosteroids for prevention of postoperative AF are warranted before their routine use can be recommended.