Postoperative atrial fibrillation

The association of hemoglobin with postoperative delirium and atrial fibrillation after cardiac surgery: a retrospective sub-study

BACKGROUND

Most cardiac surgery patients experience postoperative anemia. Delirium and Atrial Fibrillation (AF) are common and independent predictors of morbidity and mortality. Few reports examine their association with postoperative anemia. This study aims to quantify the association between anemia and these outcomes in patients undergoing cardiac surgery.

METHODS

This post-hoc analysis of the DECADE randomized controlled trial ran at six academic US hospitals. Patients aged 18-85 years with heart rate > 50 bpm undergoing cardiac surgery who had daily hemoglobin measurements in the first 5 Postoperative Days (POD) were included. Delirium was assessed twice daily with the Confusion Assessment Method for the ICU (CAM - ICU), preceded by the Richmond Agitation and Sedation Scale, with patients excluded from assessment if sedated. Patients had daily hemoglobin measurements, continuous cardiac monitoring plus twice-daily 12-lead electrocardiograms, up to POD4. AF was diagnosed by clinicians blinded to hemoglobin levels.

RESULTS

Five hundred and eighty-five patients were included. Mean postoperative hemoglobin Hazard Ratio (HR): 0.99 (95% CI 0.83, 1.19; p = 0.94) per 1 g.dL-1 hemoglobin decrease. 197 (34%) developed AF, mainly on POD = 2.3. Estimated HR = 1.04 (95% CI 0.93, 1.17; p = 0.51) per 1 g.dL-1 hemoglobin decrease.

CONCLUSIONS

Most patients undergoing major cardiac surgery were anemic in the postoperative phase. AF and delirium occurred in 34% and 12% of patients, respectively, but neither were significantly correlated with postoperative hemoglobin.

Inflammatory prognostic index predicts new-onset atrial fibrillation and mortality after on-pump coronary artery bypass grafting

OBJECTIVE

This study aimed to analyze its predictive role in incipient postoperative atrial fibrillation by constructing an inflammatory prognostic index based on hematological and biochemical parameters in patients undergoing elective isolated coronary artery surgery accompanied by cardiopulmonary bypass.

METHODS

The data of 343 patients who underwent coronary bypass surgery between May 2021 and July 2022 were evaluated. Multivariate logistic regression and recipient study characteristic curve analyses were studied by comparing the patients' hematological indices and basic clinical features between the two groups.

RESULTS

Logistic regression analysis showed that age (p<0.001), hypertension (p=0.01), and inflammatory prognostic index (p<0.001) were independent predictors of new-onset postoperative atrial fibrillation. To predict the development of postoperative atrial fibrillation, a cutoff value of 0.25 (77.8% sensitivity and 69.3% specificity) was determined for inflammatory prognostic index in the receiver-operating characteristic curve analysis (area under curve=0.798, 95% confidence interval 0.752-0.840).

CONCLUSION

Inflammatory prognostic index can be a noninvasive, easily available marker for predicting new-onset atrial fibrillation after coronary artery bypass surgery.

Atrial dysrhythmias are independent predictors of serious complications and 30-day mortality after elective bariatric surgery: a retrospective study of 731,981 patients

OBJECTIVES

The objectives of this study were to characterize the prevalence of atrial dysrhythmias for elective bariatric surgery patients and to explore their impact on postoperative outcomes.

SETTING

Data was extracted from the North American Metabolic and Bariatric Surgery Accreditation and Quality Improvement Program (MBSAQIP) data registry from 2015 to 2019.

METHODS

All primary Roux-en-Y gastric bypass and sleeve gastrectomy procedures were included. Patients with atrial dysrhythmias (ADs) were identified as patients coded as receiving preoperative therapeutic anticoagulation without a prior history of deep vein thrombosis, venous thromboembolism, pulmonary embolism, or other conditions requiring anticoagulation. Multivariable logistic regression analysis was used to determine the impact of preoperative ADs on postoperative complications and 30-day mortality.

RESULTS

We evaluated 731,981 patients, of whom 13,591 (1.9%) had preoperative ADs. Patients with ADs were more likely to be older, have a higher body mass index, and be male. Metabolic co-morbidities also were more common in those with ADs, as demonstrated by the higher rates of medication use and insulin-dependent diabetes, hypertension, dyslipidemia, and sleep apnea. After adjusting for co-morbidities using multivariable logistic regression, AD was the single greatest independent predictor of serious complications and 30-day mortality.

CONCLUSIONS

ADs were observed in approximately 2% of MBSAQIP patients. ADs are among the greatest independent predictors of serious complications and mortality, suggesting that these patients are associated with a higher perioperative risk profile warranting further optimization.

Conventional and two-dimensional strain echocardiography in predicting postoperative atrial fibrillation after coronary artery bypass grafting surgery

Background

Atrial fibrillation (AF) is a common complication after heart surgeries. Advances in imaging technologies and an understanding of the pathophysiology of preoperative left atrial (LA) dysfunction can lead to more definitive potential therapeutic approaches. This study aimed to determine the role of conventional echocardiography and LA two-dimensional (2D) strain echocardiography in assessing LA function and predicting POAF after CABG surgery.

Methods

All patients with sinus rhythm who underwent CABG surgery were enrolled. All the patients had undergone conventional echocardiography and LA 2D-strain echocardiography 24 hours before surgery. In addition to demographic, clinical, and perioperative features, electrocardiogram (ECG) and Holter monitoring were recorded.

Results

Of the 105 patients included, 85 patients (81%) were men with a mean age of 60.26±10.61 years. POAF was seen in 22.9% of patients during hospitalization, and AF duration was 10 hours (median; IQR: 2.0-19.5). AF patients had a higher LA volume index (LAVI) than patients with sinus rhythm (p=0.018). Patients with sinus rhythm had higher rates of LA reservoir (26.97±6.87 VS. 20.46±4.27, p<0.001), LA contractile (14.98±3.68 VS. 12.76±3.72, p =0.012) and LA global strain (24.28±6.57 VS. 17.71±4.11, p<0.001) than AF patients. The results of the multivariate logistic regression showed that LAVI (p=0.014) and LA global strain (p=0.027) were independent predictors of AF detection.

Conclusion

Compared to conventional echocardiography, 2D-strain echocardiography is a more effective diagnostic method to predict the possibility of post-CABG AF.

Association between perioperative hypotension and postoperative delirium and atrial fibrillation after cardiac surgery: A post-hoc analysis of the DECADE trial

STUDY OBJECTIVE

To test the hypotheses that in adults having cardiac surgery with cardio-pulmonary bypass, perioperative hypotension increases the risk of delirium and atrial fibrillation during the initial five postoperative days.

DESIGN

Sub-analysis of the DECADE multi-center randomized trial.

SETTING

Patients who had cardiac surgery with cardiopulmonary bypass at the Cleveland Clinic.

INTERVENTIONS

In the underlying trial, patients were randomly assigned 1:1 to dexmedetomidine or normal saline placebo.

MEASUREMENTS

Intraoperative mean arterial pressures were recorded at 1-min intervals from arterial catheters or at 1-5-min intervals oscillometrically. Postoperative blood pressures were recorded every half-hour or more often. The co-primary outcomes were atrial fibrillation and delirium occurring between intensive care unit admission and the earlier of postoperative day 5 or hospital discharge. Delirium was assessed twice daily during the initial 5 postoperative days while patients remained hospitalized with the Confusion Assessment Method for the intensive care unit. Assessments were made by trained research fellows who were blinded to the dexmedetomidine administration.

MAIN RESULTS

There was no significant association between intraoperative hypotension and delirium, with an adjusted odds ratio of 0.94 (95% CI: 0.81, 1.09; P = 0.419) for a doubling in AUC of mean arterial pressure (MAP) <60 mmHg. An increase in intraoperative AUC of MAP <60 mmHg was not significantly associated with the odds of atrial fibrillation (adjusted odds ratio = 0.99; 95% CI: 0.87, 1.11; P = 0.819). Postoperative MAP <70 mmHg per hour 1.14 (97.5% CI: 1.04,1.26; P = 0.002) and MAP <80 mmHg per hour 1.05 (97.5%: 1.01, 1.10; P = 0.010) were significantly associated with atrial fibrillation.

CONCLUSIONS

In patients having cardiac surgery with cardio-pulmonary bypass, neither intraoperative nor postoperative hypotension were associated with delirium. Postoperative hypotension was associated with atrial fibrillation, although intraoperative hypotension was not.

Association Between Perioperative Atrial Fibrillation and Long-term Risks of Stroke and Death in Noncardiac Surgery: Systematic Review and Meta-analysis

BACKGROUND

Atrial fibrillation (AF) is frequently reported as a complication of noncardiac surgery. It is unknown whether new-onset perioperative AF is associated with an increased risk of stroke and death beyond the perioperative period. We performed a systematic review and meta-analysis to assess the long-term risks of stroke and mortality associated with new-onset perioperative AF after noncardiac surgery.

METHODS

MEDLINE and EMBASE were searched from inception to March 2020 for studies reporting on the association between perioperative AF and the risk of stroke and death occurring beyond 30 days after noncardiac surgery. Reference screening, study selection, data extraction, and quality assessment were performed in duplicate. Data were pooled using inverse variance-weighted random-effects models and presented as risk ratios (RRs).

RESULTS

From 7344 citations, we included 31 studies (3,529,493 patients). The weighted mean incidence of perioperative AF was 0.7%. During a mean follow-up of 28.1 ± 9.4 months, perioperative AF was associated with an increased risk of stroke (1.5 vs 0.9 strokes per 100 patient-years; RR: 2.9, 95% confidence interval [CI]: 2.1-3.9, I2 = 78%). Perioperative AF was also associated with a significantly higher risk of all-cause mortality (21.0 vs 7.6 deaths per 100 patient-years; RR: 1.8, 95% CI: 1.5-2.2, I2 = 94%). The pooled adjusted hazard ratios for stroke and all-cause mortality were 1.9 (95% CI: 1.6-2.2, I2 = 31%) and 1.5 (95% CI: 1.3-1.7, I2 = 20%), respectively.

CONCLUSIONS

Patients who had perioperative AF after noncardiac surgery had a higher long-term risk of stroke and mortality compared with patients who did not. Whether this risk is modifiable with oral anticoagulation therapy should be investigated.

Postoperative atrial fibrillation is related to a worse outcome in patients undergoing surgery for hip fracture

Few information exist about incidence and prognostic significance of postoperative atrial fibrillation (POAF) in patients undergoing hip fracture surgery. In the period comprised between January 2012 and December 2016, we evaluated 3129 patients referred for hip fracture. At hospital admission 277 were in permanent atrial fibrillation and were excluded from the study. POAF was defined as symptomatic or asymptomatic AF of duration > 10 min occurring during hospitalization after hip surgery. In-hospital and 1-year outcomes of POAF patients were compared to that of an age- and sex-matched hip fracture control group. Survival rates were estimated by Kaplan-Meier curves and differences between groups compared by log-rank test. One hundred and four patients (mean age 83.7 years, men 27%) developed POAF (3.6%). Time of onset after surgery was on average 2 days after surgery. Eight POAF patients died during hospitalization. 81.7% were discharged in sinus rhythm. Patients with POAF had a longer time to surgery (3.8 ± 3.3 vs. 2.4 ± 1.6 days, p = 0.0007) and length of hospital stay (19.7 ± 10.4 vs. 14.4 ± 5.1 days p < 0.0001) in comparison to control group. Eight patients had AF recurrence during follow-up. 1-year mortality was significantly higher in POAF group in comparison to control group (39.3. vs 20.9%, p < 0.001). Postoperative atrial fibrillation in patients undergoing hip fracture surgery is associated with a longer length of hospital stay in comparison to patients who maintain stable sinus rhythm. Moreover, these patients had a significant higher mortality at 1-year follow-up.

Risk factors and survival analysis of arrhythmia following lung cancer surgery: a retrospective study

Background

Surgical treatment of lung cancer is one of the important treatments for early-stage non-small cell lung cancer (NSCLC). However, arrhythmia, especially atrial fibrillation (AF) and supraventricular arrhythmia, are quite common among patients after surgical treatment of lung cancer. The impact of postoperative arrhythmia (PA) on survival is rarely reported. Our aim was to evaluate the risk factors of PA and its impact on overall survival (OS) after lung cancer surgery.

Methods

A total of 344 patients diagnosed with NSCLC who underwent lung cancer surgery were enrolled in this study. These patients were divided into two groups based on the occurrence of PA. Univariate and multivariate logistic regression analyses were conducted to identify the risk factors of PA. The Kaplan-Meier method was applied to show the OS differences between the two groups.

Results

The incidence of PA was 16% (55/344). Among these 55 patients, 20 had AF, 30 had sinus tachycardia, and 5 had premature beats. A total of 332 patients underwent lung cancer radical resection. Operation type (P<0.001), preoperative abnormal ECG (P=0.032), transfusion (P=0.016), postoperative serum potassium concentration (P=0.001) and clinical stage (P<0.05) were risk factors for PA. PA (HR 2.083, 95% CI, 1.334–3.253; P=0.001), age (HR 1.543, 95% CI, 1.063–2.239; P=0.025) and mediastinal lymph node metastasis (HR 2.655, 95% CI, 1.809–3.897; P<0.001) were independent prognostic risk factors for OS by multivariate cox analysis.

Conclusions

We identified PA as an independent prognostic risk factor to predict poor OS in patients who underwent lung cancer surgery and had risk factors for PA. We therefore provides guidance for PA in improving the prognosis of lung cancer patients.

Surgical factors associated with new-onset postoperative atrial fibrillation after lung resection: the EPAFT multicentre study

PURPOSE OF THE STUDY

Postoperative atrial fibrillation (POAF) is a recognised complication in approximately 10% of major lung resections. In order to best target preoperative treatment, this study aimed at determining the association of incidence of POAF in patients undergoing lung resection to surgical and anatomical factors, such as surgical approach, extent of resection and laterality.

STUDY DESIGN

Evaluation of Post-operative Atrial Fibrillation in Thoracic surgery (EPAFT): a multicentre, population-based, retrospective, cross-sectional, observational study including 1367 patients undergoing lung resections between April 2016 and March 2017. The primary outcome was the presence of POAF following resection. POAF was defined as at least one episode of symptomatic or asymptomatic AF confirmed by ECG within 7 days from the thoracic procedure or prior to discharge from the hospital.

RESULTS

POAF was observed in 7.4% of patients: 3.1% in minor resection (video-assisted thoracoscopic surgery (VATS): 2.5%; thoracotomy: 3.8%), 9.0% in simple lobectomy (VATS: 7.3%, thoracotomy: 9.9%), 6.0% in complex resection (thoracotomy: 6.3%) and 11.4% in pneumonectomy. POAF was higher in left (4.0%) vs right (2.4%) minor resections, and in left (9.9%) vs right (8.3%) lobectomy, but higher in right (7.5%) complex resections, and the highest in right pneumonectomy (17.6%). No significant variations were observed as per sex, laterality or resected lobes. A positive univariable and multivariable association was observed for increasing age and increasing extent of resection, but not thoracotomy. Median (Q1-Q3) hospital stay was 9 (7-14) days in POAF and 5 (4-7) days in non-AF patients (p<0.001), with an increased cerebrovascular accident burden (p<0.001) and long-term mortality (p<0.001).

CONCLUSIONS

Among patients undergoing lung resection, POAF was significantly associated with age, increasing invasiveness of approach and increasing extent of resection. In addition, POAF carried a significant long-term mortality rate and burden of cerebrovascular accident. Appropriate prophylaxis should be targeted at these groups.

Mitochondrial genetic effect on atrial fibrillation: A case-control study

Atrial fibrillation (AF) is a common arrhythmia in the general population and following cardiac surgery. The influence of mitochondrial genomics on AF pathogenesis is not fully understood. We analyzed mitochondrial variables from 78 human atrial samples collected from cardiac surgeries in the following groups: 1) permanent preoperative AF; 2) preoperative sinus rhythm (SR) with postoperative AF; and 3) pre-/postoperative SR. Haplogroup H appeared offer protection against, and haplogroup U predispose to permanent AF. mtDNA content was higher in group 2 than in 3. These findings contribute to a better understanding of the influence of mitochondria on AF pathogenesis.

Postoperative New-Onset Atrial Fibrillation following Noncardiac Operations: Prevalence, Complication, and Long-Term MACE

Background

Postoperative new-onset atrial fibrillation (POAF) is a common complication following cardiothoracic surgery, but little is known regarding its occurrence and outcome following noncardiothoracic surgery. This study was intended to examine the incidence of POAF in noncardiothoracic surgeries performed under general anesthesia and its effects on the length of hospitalization stay, short-term and long-term morbidity, and mortality. Methodology. We conducted a retrospective observational descriptive study. The study population consists of patients hospitalized in surgical wards from January 2014 to December 2017. Surgery was defined as noncardiac or thoracic procedure conducted under general anesthesia.

Results

A total of 24,125 general anesthesia operations were performed at 7 surgical wards. About two-fifth of the operations (40%) were operated electively, and the rest underwent emergency surgery. The mean age was 63.78 ± 11.50, and more than half (56.9%) of the participants were female. The prevalence of POAF was 2.69 per 1000 adult patients (95% CI: 2.11–3.43) and vary significantly among wards. The highest prevalence was observed after hip fixation and laparotomy surgeries (54.9 and 26.7 per 1000 patients, respectively). The median length of hospitalization was significantly higher in POAF patients (21.0 vs. 4.8 days, p < 0.001). Patients who developed POAF had significantly higher mortality rates, both inhospital (200 vs. 7.56 deaths per 1000, p=0.001) and 1 year (261.5 vs. 33.3 per 1000, p=0.001, respectively). There was no significant association between outcome and treatment modalities such as rate or rhythm control and anticoagulant use.

Conclusion

New-onset AF following noncardiac surgery is rare, yet poses significant clinical implications, both immediate and long-term. POAF is associated with a longer length of hospitalization and a significantly higher mortality rate, both in short- and long-term.

Frequency of postoperative atrial fibrillation and related parameters in patients who underwent sleeve gastrectomy for obesity

BACKGROUND

In this study, we planned to determine the frequency of postoperative AF and its related parameters in morbidly obese patients who underwent bariatric surgery.

METHODS

The study included 300 patients with morbidly obese who had no history of AF and underwent successful bariatric surgery. Routine anamnesis, physical examination and laboratory parameters of the patients were recorded. Patients with postoperative AF were detected. The participants were grouped as patients with and without AF.

RESULTS

Postoperative AF occurred in 19 (6.3%) patients. Age, BMI and LAd diameter parameters independently determined the presence of AF. When the ROC curve was performed to identify patients with AF, the area under the ROC curve was found to be 0.841, 0.785 and 0.902 for age, BMI and LAd diameter, respectively. According to this analysis, 50 years for age, 43 kg/m² for BMI and 40 mm for LAd were used to determine patients with AF with acceptable sensitivity and specificity (>70% each).

CONCLUSIONS

The most important determinants of postoperative AF are age, LAd and basal BMI. Therefore, morbidly obese patients with LAd >40 mm, BMI >43 kg/m² and >50 years of age should be followed up more closely for postoperative AF development and preoperative precautions should be taken to prevent AF development.

Hemodynamic effects of Vernakalant in cardio-surgical ICU-patients treated for recent-onset postoperative atrial fibrillation

Postoperative atrial fibrillation (POAF) is one of the most frequent complications after cardiothoracic surgery and a predictor for postoperative mortality and prolonged ICU-stay. Current guidelines suggest the multi-channel inhibitor Vernakalant as a treatment option for rhythm control. However, rare cases of severe hypotension and cardiogenic shock following drug administration have been reported. To elucidate the impact of Vernakalant on hemodynamics, we included ten ICU patients developing POAF after elective cardiac surgery, all of them awake and breathing spontaneously, in this prospective trial. Patients received the recommended dosage of Vernakalant and were clinically observed and monitored (heart rate, invasive blood pressure, pulse oximetry, central venous pressure) in 1-minute-intervals for 20 minutes before- and 120 minutes after the first dose of Vernakalant. The median time from the end of surgery until occurrence of POAF amounted up to 52.8 [45.9–77.4] hours, it took 3.5 [1.2–10.1] hours from occurrence of POAF until the first application of Vernakalant. All patients received catecholamine support with epinephrine that was held steady and not dynamic throughout the observational phase. We noted stable hemodynamic conditions, with a trend towards a reduction in heart rate throughout the 120 minutes after drug administration. In 7 patients (70%), conversion to sustained sinus rhythm (SR) occurred within 8.0 minutes [6.0–9.0]. No serious adverse events (SAEs) were noted during the observation period. In this prospective trial in ICU-patients showing POAF after cardiac surgery, intravenous Vernakalant did not induce clinically relevant negative effects on patients’ hemodynamics but resulted in conversion to sustained SR after a median of 8.0 minutes in 7 out of ten patients.

Postoperative Atrial Fibrillation and Flutter in Liver Transplantation: An Important Predictor of Early and Late Morbidity and Mortality

Postoperative atrial fibrillation/flutter (POAF) is the most common perioperative arrhythmia and may be particularly problematic after liver transplantation (LT). This study is a single-center retrospective analysis of POAF to determine its incidence following LT, to identify risk factors, to assess its impact on clinical outcomes, and to summarize management strategies. The records of all patients who underwent LT between 2010 and 2018 were reviewed. Extracted data included pre-LT demographics and cardiac evaluation, in-hospital post-LT cardiac events, early and late complications, and survival. Among 1011 patients, the incidence of post-LT POAF was 10%. Using binary logistic regression, pre-LT history of atrial fibrillation was the strongest predictor of POAF (odds ratio [OR], 6.72; 95% confidence interval [CI], 2.00-22.57; P < 0.001), followed by history of coronary artery disease (CAD; OR, 2.52; 95% CI, 1.10-5.81; P = 0.03). Cardiac stress testing abnormality and CAD on cardiac catheterization were also associated with higher risk. Median time to POAF onset after LT was 3 days with 72% of cases resolving within 48 hours. POAF patients had greater hospital length of stay, death during the LT admission, and 90-day and 1-year mortality. POAF was an independent risk factor for post-LT mortality (OR, 2.0; 95% CI, 1.3-3.0; P < 0.01). Amiodarone was administered to 73% of POAF patients with no evidence of increased serum alanine aminotransferase levels. POAF occurred in 10% of post-LT patients with early onset and rapid resolution in most affected patients. POAF patients, however, had significant morbidity and mortality, suggesting that POAF is an important marker for worse early and late post-LT outcomes.

Incidence, Management, Prevention and Outcome of Post-Operative Atrial Fibrillation in Thoracic Surgical Oncology

Atrial fibrillation (AF) is a common supraventricular arrhythmia, a recognized risk factor for ischemic stroke, as a potential driver for heart failure (HF). Cancer patients have an increased risk for AF, even not including any cancer-specific treatment, as surgery or chemotherapy. The mechanism is multifactorial, with inflammation and changes in autonomic tone as critical actors. Commonly, AF is a recurrent complication of the post-operative period in cancer surgery (especially thoracic). Recent papers confirmed a significant incidence of post-operative (non-cardiac surgery) AF (PAF), partially mitigated by the use of prophylactic (rate o rhythm control) treatments. A relevant difference, in terms of mean hospitalization time, emerges between patients developing PAF and those who do not, while long term impact remains a matter of debate, due to several potential confounding factors. Besides clinical predictors, structural (i.e., echocardiographic) and bio-humoral findings may help in risk prediction tasks. In this respect, pre-operative natriuretic peptides (NPs) concentrations are nowadays recognized as significant independent predictors of perioperative cardiovascular complications (including PAF), while elevated post-operative levels may further enhance risk stratification. The aim of the present paper is to trace the state of the art in terms of incidence, management, prevention, and outcome of PAF in the field of thoracic surgical oncology.

In-Hospital Postoperative Atrial Fibrillation Indicates a Poorer Clinical Outcome after Myectomy for Obstructive Hypertrophic Cardiomyopathy

Objectives: This study aims to investigate the risk factors of in-hospital postoperative atrial fibrillation (POAF) and the impact of POAF on the clinical outcome in hypertrophic cardiomyopathy (HCM) patients who underwent myectomy.

Methods: Data from a total of 494 obstructive HCM patients, who had undergone preoperative cardiac magnetic resonance (CMR) testing and who underwent myectomy at Fuwai Hospital from June 2011 to June 2016, were collected.

Results: Multivariate logistic regression analysis showed that old age (odds ratio [OR], 4.326; 95% confidence interval [CI], 2.248–8.325; p <0.001), maximal left atrium volume (LAV) (OR, 1.137; 95% CI, 1.075–1.202; p <0.001), and hypertension (OR, 2.754; 95% CI, 1.262–6.007; p = 0.011) were associated with the incidence of POAF. In the patients without preoperative AF, Cox regression analysis demonstrated that POAF (p = 0.002), decreased left atrium (LA) ejection fraction (LAEF) (p = 0.036), concomitant procedure (p = 0.039), and postoperative residual moderate or severe mitral valve regurgitation (p = 0.030) were independent predictors of composite cardiovascular events.

Conclusions: POAF indicated a poorer clinical outcome after myectomy for obstructive HCM patients, which was similar to those with preoperative AF. Elevated LAV was independently related to POAF onset in HCM patients who underwent myectomy.

Comparison Effect of Tranexamic Acid (TA) and Tranexamic Acid Combined with Vitamin C (TXC) on Drainage Volume and Atrial Fibrillation Arrhythmia in Patients Undergoing Cardiac Bypass Surgery: Randomized Clinical Trial

BACKGROUND

Tranexamic acid and vitamin C are potent antifibrinolytic and oxidative stress agents that reduce blood loss and transfusion blood in cardiopulmonary bypass (CPB).

OBJECTIVES

The aim of this study was to evaluate the efficacy of tranexamic acid (TA) and tranexamic acid combined with vitamin C (TXC) on drainage volume (blood loss) and atrial fibrillation (AF) in patients undergoing cardiac bypass surgery in Gorgan, Shafa hospital, Iran.

METHODS

This study is a double-blind randomized clinical trial. A sample size of 120 candidates of cardiac bypass surgery were included in this prospective study. Patients were randomly assigned to treatments in two groups. In both groups, 50 mg/kg tranexamic acid was administered intravenously directly before sternotomy: group A (N = 58) patients received tranexamic acid (TA) only and group B (N = 62) tranexamic acid with vitamin C (TXC) half an hour before surgery and 2 g vitamin C with 100 mL 0.9% saline were injected. Subsequently, during 4 days after surgery, 1000 mg of vitamin C and 100 cc 0.9% saline was infused every day. Intraoperative and postoperative blood loss (volume of blood in the drain) and atrial fibrillation complications were recorded for 24 hours after the operation.

RESULTS

The patients who received vitamin C had less bleeding during operation and in the early hours post-operation. Patients in (TA) group had mean drainage of 34.41 milliliter more than patients in (TXC) group (P < 0.001). Chi-square test showed that arrhythmia (AF) condition was the same in the two groups during 14 times of study (four times during operation and ten times up to 24 hours after the operation), and AF arrhythmia in the two groups was less than 5%.

CONCLUSIONS

In this study tranexamic acid with vitamin C have a positive effect on the amount of drainage (blood loss) and there was no significant difference in the incidence of AF between two groups.

Epicardial Application of Hydrogel with Amiodarone for Prevention of Postoperative Atrial Fibrillation in Patients After Coronary Artery Bypass Grafting

The objective of this study was to assess the safety and efficacy of local epicardial application of amiodarone-releasing hydrogel for prevention of postoperative atrial fibrillation (POAF) in patients after coronary artery bypass grafting. Patients were randomized into two groups: with the application of amiodarone-releasing hydrogel and the control group. It included 60 patients (47 males, 13 females) (mean age of 62 ± 8.5). POAF incidence differences were statistically significant between two groups: in the study group, the POAF incidence was 3.3%, while in the control group, the POAF incidence was 37% (p < 0.001). Statistically significant differences were revealed in the PQ interval duration. The risk of POAF incidence was calculated using the Cox regression model: the age and the application of amiodarone-releasing hydrogel application were statistically significant. Hospital length of stay in two groups was also different (р < 0.001). The age and the application of amiodarone-releasing hydrogel were statistically significant for POAF incidence.

New-Onset Atrial Fibrillation After PCI or CABG for Left Main Disease: The EXCEL Trial

BACKGROUND

There is limited information on the incidence and prognostic impact of new-onset atrial fibrillation (NOAF) following percutaneous coronary intervention (PCI) and coronary artery bypass grafting (CABG) for left main coronary artery disease (LMCAD).

OBJECTIVES

This study sought to determine the incidence of NOAF following PCI and CABG for LMCAD and its effect on 3-year cardiovascular outcomes.

METHODS

In the EXCEL (Evaluation of XIENCE Versus Coronary Artery Bypass Surgery for Effectiveness of Left Main Revascularization) trial, 1,905 patients with LMCAD and low or intermediate SYNTAX scores were randomized to PCI with everolimus-eluting stents versus CABG. Outcomes were analyzed according to the development of NOAF during the initial hospitalization following revascularization.

RESULTS

Among 1,812 patients without atrial fibrillation on presentation, NOAF developed at a mean of 2.7 ± 2.5 days after revascularization in 162 patients (8.9%), including 161 of 893 (18.0%) CABG-treated patients and 1 of 919 (0.1%) PCI-treated patients (p < 0.0001). Older age, greater body mass index, and reduced left ventricular ejection fraction were independent predictors of NOAF in patients undergoing CABG. Patients with versus without NOAF had a significantly longer duration of hospitalization, were more likely to be discharged on anticoagulant therapy, and had an increased 30-day rate of Thrombolysis In Myocardial Infarction major or minor bleeding (14.2% vs. 5.5%; p < 0.0001). By multivariable analysis, NOAF after CABG was an independent predictor of 3-year stroke (6.6% vs. 2.4%; adjusted hazard ratio [HR]: 4.19; 95% confidence interval [CI]: 1.74 to 10.11; p = 0.001), death (11.4% vs. 4.3%; adjusted HR: 3.02; 95% CI: 1.60 to 5.70; p = 0.0006), and the primary composite endpoint of death, MI, or stroke (22.6% vs. 12.8%; adjusted HR: 2.13; 95% CI: 1.39 to 3.25; p = 0.0004).

CONCLUSIONS

In patients with LMCAD undergoing revascularization in the EXCEL trial, NOAF was common after CABG but extremely rare after PCI. The development of NOAF was strongly associated with subsequent death and stroke in CABG-treated patients. Further studies are warranted to determine whether prophylactic strategies to prevent or treat atrial fibrillation may improve prognosis in patients with LMCAD who are undergoing CABG. (Evaluation of XIENCE Versus Coronary Artery Bypass Surgery for Effectiveness of Left Main Revascularization [EXCEL]; NCT01205776).

Selective brain hypothermia: feasibility and safety study of a novel method in five patients

BACKGROUND/OBJECTIVE

Reduction of brain temperature remains the most common method of neuroprotection against ischemic injury employed during cardiac surgery. However, cooling delivered via the cardiopulmonary bypass circuit is brief and cooling the body core along with the brain has been associated with a variety of unwanted effects. This study investigated the feasibility and safety of a novel selective brain cooling approach to induce rapid, brain-targeted hypothermia independent of the cardiopulmonary bypass circuit.

METHODS

This first-in-human feasibility study enrolled five adults undergoing aortic valve replacement with cardiopulmonary bypass support. During surgery, the NeuroSave system circulated chilled saline within the pharynx and upper esophagus. Brain and body core temperature were continuously monitored. Adverse effects, cardiopulmonary function, and device function were noted.

RESULTS

Patient 1 received cooling fluid for an insignificant period, and Patients 2-5 successfully underwent the cooling procedure using the NeuroSave system for 56-89 minutes. Cooling fluid was 12°C for Patients 1-3, 6°C for Patient 4, and 2°C for Patient 5. There were no NeuroSave-related adverse events and no alterations in cardiopulmonary function during NeuroSave use. Brain temperature decreased by 3°C within 15 minutes and remained at least 3.5°C colder than the body core. During a brief episode of hypotension in one patient, the brain cooled an additional 4°C in 2 minutes, briefly reaching 27.4°C.

CONCLUSION

The NeuroSave system can induce rapid brain-targeted hypothermia and simultaneously maintain a favorable body-brain temperature gradient, even during hypotension. Further studies are required to evaluate the function of the system during longer periods of use.

New-onset atrial fibrillation after esophagectomy for cancer

Esophagectomy with en-bloc lymphadenectomy after neoadjuvant chemo(radio)therapy is the standard of care for resectable locally advanced esophageal cancer. Postoperative complications may have a significant impact on the duration of hospital stay and quality of life. Early recognition and treatment of complications may reduce failure to rescue rates and improve postoperative outcomes. New-onset atrial fibrillation (AF) after esophagectomy for cancer is frequently observed, and may be related to other postoperative complications. AF could function as an early warning sign for other complications in the postoperative course after esophagectomy and may thus be of clinical value. This review discusses the pathophysiology and possible risk factors of AF, the association between AF and other postoperative complications, and the influence of AF on postoperative outcomes after esophagectomy for cancer. Furthermore, clinical recommendations for the management of new-onset AF after esophagectomy for cancer are provided.

Atrial Fibrillation and Acute Myocardial Infarction – An Inflammation-Mediated Association

Atrial fibrillation (AF) is an increasingly widespread healthcare problem. AF can frequently present as a complication in acute coronary syndromes (ACS), especially in ST-elevation acute myocardial infarction (AMI), in which case it is the most frequent supraventricular rhythm disturbance with an estimated incidence of 6.8-21%. The presence of AF in ACS heralds worse outcomes in comparison to subjects in sinus rhythm, and several studies have shown that in AMI patients, both new-onset and pre-existing AF are associated with a higher risk of major adverse cardiovascular and cerebrovascular events during hospitalization. The cause of newonset AF in AMI is multifactorial. Although still incompletely understood, the mechanisms involved in the development of AF in acute myocardial ischemic events include the neurohormonal activation of the sympathetic nervous system that accompanies the AMI, ischemic involvement of the atrial myocytes, ventricular dysfunction, and atrial overload. The identification of patients at risk for AF is of great significance as it may lead to prompt therapeutic interventions and closer follow-up, thus improving prognosis and decreasing cardiovascular and cerebrovascular events. The present manuscript aims to summarize the current research findings related to new-onset AF in AMI patients, as well as the predictors and prognostic impact of this comorbid association.

Comparison of Warfarin Requirements in Post-cardiac Surgery Patients: Valve Replacement Versus Non-valve Replacement

INTRODUCTION

Anticoagulation with warfarin affects approximately 140,000 post-cardiac surgery patients every year, yet there remains limited published data in this patient population. Dosing remains highly variable due to intrinsic risk factors that plague cardiac surgery candidates and a lack of diverse literature that can be applied to those who have undergone a cardiac surgery alternative to heart valve replacement (HVR). In the present study, our aim was to compare the warfarin requirements between HVR and non-HVR patients.

METHODS

This was a single-center, retrospective study of post-cardiac surgery patients initiated on warfarin at Mayo Clinic Hospital, Rochester, from January 1st, 2013 to October 31st, 2016. The primary outcome was the maintenance warfarin dose at the earliest of discharge or warfarin day 10 between patients with HVR and non-HVR cardiac surgeries.

RESULTS

A total of 683 patients were assessed during the study period: 408 in the HVR group and 275 in the non-HVR group. The mean warfarin maintenance doses in the HVR and non-HVR groups were 2.55 mg [standard deviation (SD) 1.52] and 2.43 mg (SD 1.21), respectively (adjusted p = 0.65). A multivariable analysis was performed to adjust for gender, age, body mass index and drug interactions.

CONCLUSIONS

This was the largest study to evaluate warfarin dose requirements in post-cardiac surgery patients and is the first to compare warfarin requirements between HVR and non-HVR patients during the immediate post-operative period. Both groups had similar warfarin requirements, which supports expanding the initial warfarin dosing recommendations of the 9th edition Chest guideline to include non-HVR patients as well as HVR patients.

A retrospective study on atrial fibrillation after coronary artery bypass grafting surgery at The National Heart Institute, Kuala Lumpur

Background: Atrial fibrillation (AF) is common after cardiac surgery and has been associated with poor outcome and increased resource utilization. The main objective of this study is to determine the incidence of POAF in Malaysia and identify the predictors of developing POAF. The secondary outcome of this study would be to investigate the difference in mortality and morbidity rates and the duration of intensive care unit (ICU), high dependency unit (HDU) and hospital stay between the two. Methods: This is a retrospective single-center, cross sectional study conducted at the National Heart Institute, Malaysia. Medical records of 637 who underwent coronary artery bypass grafting (CABG) surgery in 2015 were accrued. Pre-operative, operative and post-operative information were subsequently collected on a pre-formulated data collection sheet. Data were then analyzed using IBM SPSS v23. Results: The incidence of POAF in our study stands at 28.7% with a mean onset of 45±33 hours post operatively. Variables with independent association with POAF include advancing age, Indian population, history of chronic kidney disease, left ventricular ejection fraction and beta-blocker treatment. The mortality rate is significantly higher statistically ( p < 0.05), and similarly the incidence of stroke. The incidence of other post-operative complications was also significantly higher statistically. The duration of ICU, HDU and hospital stays were statistically longer ( p < 0.001) with higher rates of ICU readmissions and reintubations seen. Conclusion: We conclude that the incidence of POAF in Malaysia is comparable to the figures in Western countries, making POAF one of the most commonly encountered condition after CABG with similar higher rates of mortality, poor outcomes and longer duration of stay, and therefore increased cost of care. Strategies to reduce the incidence of AF after cardiac surgery should favorably affect surgical outcomes and reduce utilization of resources and thus lower cost of care.

A retrospective study on atrial fibrillation after coronary artery bypass grafting surgery at The National Heart Institute, Kuala Lumpur

Background: Atrial fibrillation (AF) is common after cardiac surgery and has been associated with poor outcome and increased resource utilization. The main objective of this study is to determine the incidence of POAF in Malaysia and identify the predictors of developing POAF. The secondary outcome of this study would be to investigate the difference in mortality and morbidity rates and the duration of intensive care unit (ICU), high dependency unit (HDU) and hospital stay between the two. Methods: This is a retrospective single-center, cross sectional study conducted at the National Heart Institute, Malaysia. Medical records of 637 who underwent coronary artery bypass grafting (CABG) surgery in 2015 were accrued. Pre-operative, operative and post-operative information were subsequently collected on a pre-formulated data collection sheet. Data were then analyzed using IBM SPSS v23. Results: The incidence of POAF in our study stands at 28.7% with a mean onset of 45±33 hours post operatively. Variables with independent association with POAF include advancing age, Indian population, history of chronic kidney disease, left ventricular ejection fraction and beta-blocker treatment. The mortality rate is significantly higher statistically ( p < 0.05), and similarly the incidence of stroke. The incidence of other post-operative complications was also significantly higher statistically. The duration of ICU, HDU and hospital stays were statistically longer ( p < 0.001) with higher rates of ICU readmissions and reintubations seen. Conclusion: We conclude that the incidence of POAF in Malaysia is comparable to the figures in Western countries, making POAF one of the most commonly encountered condition after CABG with similar higher rates of mortality, poor outcomes and longer duration of stay, and therefore increased cost of care. Strategies to reduce the incidence of AF after cardiac surgery should favorably affect surgical outcomes and reduce utilization of resources and thus lower cost of care.

Pharmacological interventions for preventing post-operative atrial fibrillation in patients undergoing cardiac surgery: a network meta-analysis protocol

INTRODUCTION

Postoperative atrial fibrillation (POAF) is the most common complication following cardiac surgery, and randomised clinical trials (RCTs) and systematic reviews have been conducted to compare and evaluate different pharmacological interventions for preventing POAF. This study aimed to explore the effect of different pharmacological interventions for prophylaxis against POAF after cardiac surgery using network meta-analysis (NMA).

METHODS AND ANALYSIS

A systematic search will be performed in PubMed, EMBASE and the Cochrane Library to identify RCTs, systematic reviews, meta-analyses or NMA of different pharmacological interventions for POAF. We will evaluate the risk of bias of the included RCTs according to the Cochrane Handbook V.5.1.0, and use GRADE to assess the quality of evidence. Standard pairwise meta-analysis, trial sequential analysis and Bayesian network meta-analysis will be used to compare the efficacy of different pharmacological interventions.

ETHICS AND DISSEMINATION

Ethics approval and patient consent are not required as this study is a meta-analysis based on published studies. The results of this NMA and trial sequential analysis will be submitted to a peer-reviewed journal for publication.

PROTOCOL REGISTRATION NUMBER

CRD42017067492.

Microvascular effects of intravenous esmolol in patients with normal cardiac function undergoing postoperative atrial fibrillation: a prospective pilot study in cardiothoracic surgery

BACKGROUND

Postoperative atrial fibrillation (POAF) is commonplace after cardiothoracic surgery. A rate control strategy using short-acting beta blockers is recommended as a first-line therapy in patients without hemodynamic instability. Microcirculatory effects of POAF and esmolol have not yet been investigated. We hypothesized that POAF without hemodynamic instability would induce microvascular dysfunction which could be reversed by intravenous esmolol.

METHODS

Twenty-five cardiothoracic surgical patients with POAF were included in the study. Microcirculation was assessed by peripheral near-infrared spectroscopy (NIRS) in association with a vascular occlusion test (VOT) before esmolol infusion, during incremental doses of esmolol (25, 50, 100, and 200 μg/kg/min), and after a return to sinus rhythm. Esmolol was given to control heart rate to between 60 and 90 beats/min. Regional tissue oxygen saturation variables (StO₂, StO₂ min, StO₂ max, and ∆StO₂) and desaturation/resaturation speeds during VOT were recorded to evaluate the microcirculation.

RESULTS

StO₂ and resaturation speed were significantly improved when POAF returned to sinus rhythm (StO₂ 64% ± 6 versus 67% ± 6, P < 0.01; resaturation speed 0.53%/s (0.42-0.97) versus 0.66%/s (0.51-1.04), P = 0.020). ∆StO₂ was significantly decreased after a return to sinus rhythm (7.9% ± 4.8 versus 6.1% ± 4.7, P = 0.026). During esmolol infusion, we found a significant decrease in both heart rate (P < 0.001) and blood pressure (P < 0.001), and a non-significant dose-dependent increase in StO₂ (P = 0.081) and resaturation speed (P = 0.087).

CONCLUSION

POAF without hemodynamic instability is associated with significant impairment in the microcirculation which could be partially reversed by intravenous esmolol.

Analysis of Circulating miR-1, miR-23a, and miR-26a in Atrial Fibrillation Patients Undergoing Coronary Bypass Artery Grafting Surgery

Atrial fibrillation (AF) is the most common arrhythmia after cardiac surgery. From a pathophysiological point of view, a myriad of factors such as trauma, atrial dilation, ischemia, mechanical myopericarditis, autonomic imbalance, loss of connexins, AF nest remodeling, inflammation, sutures, and dysfunction caused by postextracorporeal circulation can contribute to postoperative atrial fibrillation (POAF) resulting in a longer hospital stay and consequently higher cost. Recent studies showed that short fragments of RNA, called microRNA (miRNA), can contribute to the development of several cardiovascular diseases, including AF. The aim of this study was to evaluate the levels of circulating miRNAs (miR-1, -23a, and -26a) that can be involved in POAF. Patients submitted to coronary artery bypass graft surgery were grouped in POAF (24 patients) and without POAF (24 patients). Results showed older age, longer clamp-time, and more days in the intensive care unit as well as a longer total hospital stay in the POAF group. Preoperative levels of circulating miRNAs were similar. Analysis of miRNAs revealed significantly lower circulating levels of miRNA-23a (P  =  0.02) and -26a (P  =  0.01) in the POAF group during the postoperative period. Receiver operating characteristic (ROC) analysis showed the area under the ROC curve of miR-23a and miR-26a for predicting FA was 0.63 (95% confidence interval [CI]: 0.51-0.74; P  =  0.02) and 0.66 (95% CI: 0.55-0.77; P  =  0.01), respectively. Our data suggests that circulating miRNA-23a and -26a may be involved in the underlying biology of postoperative AF development.

Plasma Catecholamine Levels on the Morning of Surgery Predict Post-Operative Atrial Fibrillation

OBJECTIVES

This study sought to determine whether plasma catecholamines and monoamine oxidase-B (MOA-B) are associated with post-operative atrial fibrillation (POAF) in patients undergoing elective cardiac surgery.

BACKGROUND

Although intra- and post-operative adrenergic tone has been demonstrated to be an causative factor for POAF, the role and association of pre-operative plasma catecholamines remains unclear.

METHODS

Prior to administration of anesthesia on the morning of surgery, blood samples were obtained from 324 patients undergoing nonemergent coronary artery bypass graft and/or aortic valve surgery with cardiopulmonary bypass at East Carolina Heart Institute. The concentrations of norepinephrine (NE), dopamine (DA), epinephrine (EPI), and enzyme MAO-B were assessed in platelet-rich plasma. A log-binomial regression model was used to determine the association between quartiles of these variables and POAF.

RESULTS

Levels of NE (p = 0.0006) and EPI (p = 0.047) in the 4th quartile [Formula: see text] were positively associated with POAF, whereas DA (p = 0.0034) levels in the 4th quartile [Formula: see text] were inversely associated with POAF. Adjusting for age, heart failure (HF), and history of atrial fibrillation, the composite pre-operative (adrenergic) plasma marker [Formula: see text] was associated with a 4-fold increased occurrence of POAF (adjusted p = 0.0001). No association between plasma MAO-B and POAF was observed.

CONCLUSIONS

Our results suggest that pre-operative adrenergic tone is an important factor underlying POAF. This information provides evidence that assessment of plasma catecholamines may be a low-cost method that is easy to implement for predicting which patients are likely to develop POAF. More investigation in a multicentric setting is needed to validate our results.

Comparison of Two Central Venous Pressure Control Strategies to Prevent Atrial Fibrillation After Coronary Artery Bypass Grafting

BACKGROUND:

Atrial fibrillation (AF) takes place in 10-40% of patients undergoing coronary artery bypass grafting (CABG), and increases cardiovascular mortality. Enlargement of atrial chambers is associated with increased AF incidence, so patients with higher central venous pressure (CVP) are expected to have larger atrial distension, which increases AF incidence.

OBJECTIVE:

To compare post-CABG AF incidence, following two CVP control strategies.

METHODS:

Interventional, randomized, controlled clinical study. The sample comprised 140 patients undergoing CABG between 2011 and 2015. They were randomized into two groups, G15 and G20, with CVP maintained ≤ 15 cmH2O and ≤ 20 cmH2O, respectively.

RESULTS:

70 patients were included in each group. The AF incidence in G15 was 8.57%, and in G20, 22.86%, with absolute risk reduction of 14.28%, and number needed to treat (NNT) of 7 (p = 0.03). Mortality (G15 = 5.71%; G20 = 11.42%; p = 0.07), hospital length of stay (G15 = 7.14 days; G20 = 8.21 days; p = 0.36), number of grafts (median: G15 = 3, G2 = 2; p = 0.22) and cardiopulmonary bypass use (G15 = 67.10%; G20 = 55.70%; p = 0.22) were statistically similar. Age (p = 0.04) and hospital length of stay (p = 0.001) were significantly higher in patients who developed AF in both groups.

CONCLUSION:

Keeping CVP low in the first 72 post-CABG hours reduces the relative risk of AF, and may be useful to prevent AF after CABG.

FUNDAMENTO:

A fibrilação atrial (FA) ocorre em 10-40% dos pacientes submetidos a cirurgia de revascularização miocárdica (RM), e eleva a mortalidade cardiovascular. Como o aumento dos átrios está associado ao aumento da incidência de FA, espera-se que pacientes com pressão venosa central (PVC) mais alta tenham maior distensão atrial, o que eleva a incidência dessa arritmia.

OBJETIVO:

Comparar a incidência de FA em pós-operatório de RM, seguindo duas estratégias de controle de PVC.

MÉTODOS:

Estudo clínico randomizado controlado intervencionista. A amostra foi composta por 140 pacientes submetidos a RM entre 2011 e 2015. Os pacientes foram randomizados em dois grupos, G15 e G20, mantidos com PVC máxima de 15 cmH2O e 20 cmH2O, respectivamente.

RESULTADOS:

Foram incluídos 70 pacientes em cada grupo. A incidência da arritmia em G15 foi de 8,57% e, no G20, de 22,86%, com redução de risco absoluto de 14,28% e número necessário para tratar (NNT) de 7 (p = 0,03). Mortalidade (G15 = 5,71%; G20 = 11,42%; p = 0,07), tempo de internamento (G15 = 7,14 dias; G20 = 8,21 dias; p = 0,36), número de enxertos (medianas: G15 = 3, G2 = 2; p = 0,22) e uso de circulação extracorpórea (G15 = 67,10%; G20 = 55,70%; p = 0,22) mostraram-se estatisticamente semelhantes. A idade (p = 0,04) e o tempo de internamento (p = 0,001) foram significativamente maiores nos pacientes que desenvolveram FA nos dois grupos.

CONCLUSÃO:

Manter a PVC com valores mais baixos nas primeiras 72h após a cirurgia de RM reduz o risco relativo de FA e pode ser uma ferramenta útil na prevenção da FA após RM.

Stroke Prevention for Patients with Atrial Fibrillation: Beyond the Guidelines

Atrial fibrillation (AF) is the most common serious heart rhythm disorder, with a lifetime incidence of 1 in 4 for patients >40 years of age[1]. AF is a major cause of death and disability, as it is associated with a 4-5 fold increase in the risk of ischemic stroke[2]. In patients with AF, oral anticoagulation (OAC) therapy can reduce the risk of stroke by about two-thirds and the risk of all-cause mortality by approximately one-quarter, but is associated with an increased risk of bleeding[3], [4]. Atrial fibrillation (AF) is the most common serious heart rhythm disorder and is associated with an increased risk of ischemic stroke. This risk can be moderated with oral anticoagulation therapy, but the decision to do so must be balanced against the risks of bleeding. Herein, we discuss three emerging areas where more high-quality evidence is required to guide risk stratification: 1) the relationships between the pattern and burden of AF and stroke 2) the risk conferred by short episodes of device-detected "sub-clinical" atrial fibrillation (SCAF) and 3) the significance of AF that occurs transiently with stress (AFOTS), as is often detected during medical illness or after surgery. Risk stratification is important to identify patients with AF who can benefit from OAC therapy. There are, however, several common clinical scenarios where guidelines do not yet provide direction for stroke prevention; or do so based on limited high-quality evidence.

Meta-analysis Identifies Serum C-Reactive Protein as an Indicator of Atrial Fibrillation Risk After Coronary Artery Bypass Graft

A meta-analysis-based study was conducted to examine the clinical value of serum C-reactive protein (CRP) levels in predicting postoperative atrial fibrillation (POAF) in patients with coronary artery disease (CAD) who underwent coronary artery bypass graft. Computer-based search of scientific literature databases was performed to identify relevant studies in strict accordance with our inclusion and exclusion criteria. Data extracted from the selected studies were used to perform meta-analysis using the STATA 12.0 statistical software. Standardized mean differences (SMDs) with their 95% confidence interval (95% CI) were calculated. The database search strategy initially identified 62 articles (Chinese = 17, English = 45). After multiple levels of screening and validation, 15 case-control studies (Chinese = 1, English = 14), containing of a total of 3110 atrial fibrillation patients (POAF = 925, non-POAF = 2185), were selected for our meta-analysis. The meta-analysis results confirmed that serum CRP level was remarkably higher in patients with POAF compared with non-POAF (SMD = 1.36; 95% CI, 0.44-2.28; P = 0.004). Ethnicity-stratified analysis revealed that elevated serum CRP levels were associated with an increased risk of POAF in white patients with CAD (SMD = 0.85; 95% CI, 0.12-1.58; P = 0.022), but not Asian patients with CAD (SMD = 3.31, 95% CI, -0.04 to 6.66; P = 0.053). Elevated CRP levels, indicating profound inflammation, may be associated with significantly increased risk of POAF in patients with CAD who underwent coronary artery bypass graft. Thus, serum CRP levels are important for early diagnosis and monitoring of POAF in high-risk patients.

Improving Incidence of Postoperative Atrial Fibrillation After Cardiac Surgery Using Simplified Clinical Practice Guidelines

OBJECTIVES

Postoperative atrial fibrillation (POAF) remains a major risk after cardiac surgery. Twelve percent patients admitted to this unit postcardiac surgery experienced POAF, which led to hemodynamic instability, increased risk of stroke, and increased length of postoperative intensive care unit stay. Our aim was to decrease the incidence of POAF in the cardiothoracic intensive care unit by the end of April 2014.

METHODS

Design-Retrospective data analysis. Settings-Postcardiac surgery intensive care in a tertiary hospital.

PARTICIPANTS

Postcardiac surgery patients. Intervention-A clinical practice guideline (CPG) was developed to promote early prevention and to improve adherence to POAF prophylaxis recommendations. Patient's charts were our key performance indicator. Primary outcome measure-Percentage of patients who developed episodes of POAF within the first 24 hours of cardiac surgery. Process measures-compliance with the newly developed CPG and early postoperative patient assessment. Balance measure-early administration of β-blocker.

RESULTS

We were able to decrease POAF to 8% after intervention. Compliance with early assessment improved from 25% to 87%. Compliance with adherence to the CPG was 80%. Adherence to the newly developed paper form was the major challenge that could be overcome by an electronic form. We hope to decrease the incidence of POAF to 6% and develop an electronic form by the end of December 2014.

CONCLUSION

This quality improvement project changed the strategy and succeeded in decreasing the incidence of POAF after cardiac surgery. It also improved early assessment of risk factors.

CTS trials network: Rate control vs rhythm control for atrial fibrillation after cardiac surgery - Do bitter pills have blessed effects?

New onset AF is a very common sequel of cardiac surgery with an incidence reaching 50% in some studies. This post-operative complication leads to increased morbidity, hospital stay and, consequently, hospital costs¹. Currently there is a great variability in the management of this condition. Despite efforts to produce best practice guidelines², what best to do for a patient who develops AF post-operatively remains a question. In a systematic attempt to find an answer to this question, the Cardiothoracic Trials Network have recently published the results of their trial “Rate Control Versus Rhythm Control for Atrial Fibrillation After Cardiac Surgery”³ (clinicaltrials.gov number: NCT02132767).

Pathophysiology of cancer therapy-provoked atrial fibrillation

Atrial fibrillation (AF) occurs with increased frequency in cancer patients, especially in patients who undergo surgery or chemotherapy. AF disturbs the prognosis of cancer patients and challenges therapeutic outcomes of cancer treatment. Elucidating the mechanisms of cancer-induced AF would help identify specific strategies for preventing AF occurrence. In addition to concurrent risk factors of cancer and AF, cancer surgery, side effects of anticancer agents, and cancer-associated immune responses play critical roles in the genesis of AF. In this review, we provide succinct potential mechanisms of AF genesis in cancer patients.

Rate Control versus Rhythm Control for Atrial Fibrillation after Cardiac Surgery

BACKGROUND

Atrial fibrillation after cardiac surgery is associated with increased rates of death, complications, and hospitalizations. In patients with postoperative atrial fibrillation who are in stable condition, the best initial treatment strategy--heart-rate control or rhythm control--remains controversial.

METHODS

Patients with new-onset postoperative atrial fibrillation were randomly assigned to undergo either rate control or rhythm control. The primary end point was the total number of days of hospitalization within 60 days after randomization, as assessed by the Wilcoxon rank-sum test.

RESULTS

Postoperative atrial fibrillation occurred in 695 of the 2109 patients (33.0%) who were enrolled preoperatively; of these patients, 523 underwent randomization. The total numbers of hospital days in the rate-control group and the rhythm-control group were similar (median, 5.1 days and 5.0 days, respectively; P=0.76). There were no significant between-group differences in the rates of death (P=0.64) or overall serious adverse events (24.8 per 100 patient-months in the rate-control group and 26.4 per 100 patient-months in the rhythm-control group, P=0.61), including thromboembolic and bleeding events. About 25% of the patients in each group deviated from the assigned therapy, mainly because of drug ineffectiveness (in the rate-control group) or amiodarone side effects or adverse drug reactions (in the rhythm-control group). At 60 days, 93.8% of the patients in the rate-control group and 97.9% of those in the rhythm-control group had had a stable heart rhythm without atrial fibrillation for the previous 30 days (P=0.02), and 84.2% and 86.9%, respectively, had been free from atrial fibrillation from discharge to 60 days (P=0.41).

CONCLUSIONS

Strategies for rate control and rhythm control to treat postoperative atrial fibrillation were associated with equal numbers of days of hospitalization, similar complication rates, and similarly low rates of persistent atrial fibrillation 60 days after onset. Neither treatment strategy showed a net clinical advantage over the other. (Funded by the National Institutes of Health and the Canadian Institutes of Health Research; ClinicalTrials.gov number, NCT02132767.).

Decreased Bioenergetic Health Index in monocytes isolated from the pericardial fluid and blood of post-operative cardiac surgery patients

Translational bioenergetics requires the measurement of mitochondrial function in clinically relevant samples and the integration of the data in a form that can be applied to personalized medicine. In the present study, we show the application of the measurement of the Bioenergetic Health Index (BHI) to cardiac surgery patients.

Monitoring the bioenergetics of leucocytes is now emerging as an important approach in translational research to detect mitochondrial dysfunction in blood or other patient samples. Using the mitochondrial stress test, which involves the sequential addition of mitochondrial inhibitors to adherent leucocytes, we have calculated a single value, the Bioenergetic Health Index (BHI), which represents the mitochondrial function in cells isolated from patients. In the present report, we assess the BHI of monocytes isolated from the post-operative blood and post-operative pericardial fluid (PO-PCF) from patients undergoing cardiac surgery. Analysis of the bioenergetics of monocytes isolated from patients’ PO-PCF revealed a profound decrease in mitochondrial function compared with monocytes isolated from their blood or from healthy controls. Further, patient blood monocytes showed no significant difference in the individual energetic parameters from the mitochondrial stress test but, when integrated into the BHI evaluation, there was a significant decrease in BHI compared with healthy control monocytes. These data support the utility of BHI measurements in integrating the individual parameters from the mitochondrial stress test into a single value. Supporting our previous finding that the PO-PCF is pro-oxidant, we found that exposure of rat cardiomyocytes to PO-PCF caused a significant loss of mitochondrial membrane potential and increased reactive oxygen species (ROS). These findings support the hypothesis that integrated measures of bioenergetic health could have prognostic and diagnostic value in translational bioenergetics.

Implementation and preliminary validation of a new score that predicts post-operative complications

BACKGROUND

An accurate pre-operative risk assessment could reduce morbidity and mortality for high-risk surgical patients. The aim of the study was to implement and preliminary validate a new score that could predict the occurrence of post-operative complications (PoCs): the Anesthesiological and Surgical Postoperative Risk Assessment (ASPRA) score.

METHODS

The ASPRA score was created through a literature's review; a score of 1-3 was given to each identified risk factor, according to its statistical correlation with PoC. ASPRA was retrospectively applied to a derivation set of 176 surgical patients. A receiver operating characteristic (ROC) analysis evaluated the discriminating ability of the score and cutoff value in predicting the occurrence of PoCs, according to the Clavien-Dindo classification of surgical complications. The statistical validation of the score and related cutoff values was prospectively ran within a validation set of 1928 surgical patients.

RESULTS

Through ROC analysis, an ASPRA score of 7 was chosen as the cutoff value in the derivation set. In the validation set, 65.3% of patients presented a PoC (Clavien ≥ 1). In this group, ROC analysis showed an area under the curve (AUC) of 0.72, and although potentially related to the high rate of complications a high positive predictive value of 87.0% has been observed. No significant differences were found in ROC-AUC, sensitivity, specificity, or positive or negative predictive value between the derivation and validation sets (P > 0.05).

CONCLUSION

The new ASPRA score has a high positive predictive value to predict the occurrence of PoCs. Further prospective studies are required to confirm these results.

Hemoglobin-associated oxidative stress in the pericardial compartment of postoperative cardiac surgery patients

Atherosclerosis and valvular heart disease often require treatment with corrective surgery to prevent future myocardial infarction, ischemic heart disease, and heart failure. Mechanisms underlying the development of the associated complications of surgery are multifactorial and have been linked to inflammation and oxidative stress, classically as measured in the blood or plasma of patients. Postoperative pericardial fluid (PO-PCF) has not been investigated in depth with respect to the potential to induce oxidative stress. This is important because cardiac surgery disrupts the integrity of the pericardial membrane surrounding the heart and causes significant alterations in the composition of the pericardial fluid (PCF). This includes contamination with hemolyzed blood and high concentrations of oxidized hemoglobin, which suggests that cardiac surgery results in oxidative stress within the pericardial space. Accordingly, we tested the hypothesis that PO-PCF is highly pro-oxidant and that the potential interaction between inflammatory cell-derived hydrogen peroxide with hemoglobin is associated with oxidative stress. Blood and PCF were collected from 31 patients at the time of surgery and postoperatively from 4 to 48 h after coronary artery bypass grafting, valve replacement, or valve repair (mitral or aortic). PO-PCF contained high concentrations of neutrophils and monocytes, which are capable of generating elevated amounts of superoxide and hydrogen peroxide through the oxidative burst. In addition, PO-PCF primed naive neutrophils resulting in an enhanced oxidative burst upon stimulation. The PO-PCF also contained increased concentrations of cell-free oxidized hemoglobin that was associated with elevated levels of F2α isoprostanes and prostaglandins, consistent with both oxidative stress and activation of cyclooxygenase. Lastly, protein analysis of the PO-PCF revealed evidence of protein thiol oxidation and protein carbonylation. We conclude that PO-PCF is highly pro-oxidant and speculate that it may contribute to the risk of postoperative complications.