Guidelines on the prevention and management of de novo atrial fibrillation after cardiac and thoracic surgery

The efficacy and safety of intraoperative intravenous amiodarone in patients undergoing on-pump coronary artery bypass grafting surgery: a systemic review and PRISMA-compliant meta-analysis

BACKGROUND

To evaluate the clinical efficacy and safety of intraoperative intravenous amiodarone for arrhythmia prevention in on-pump coronary artery bypass grafting (CABG) patients.

METHODS

A meta-analysis of randomized controlled trials was conducted. Pubmed, Embase, Cochrane Library, Ovid, China National Knowledge Infrastructure, and the Wan Fang database until July 1th, 2023. The primary outcomes of interest included the incidences of intra- and post-operative atrial fibrillation (POAF), ventricular fibrillation, or any arrhythmia, including atrial fibrillation, ventricular fibrillation, ventricular tachycardia, premature ventricular contraction, and sinus bradycardia. For continuous and dichotomous variables, treatment effects were calculated as the weighted mean difference (WMD)/risk ratio (RR) and 95% confidence interval (CI).

RESULTS

A database search yielded 7 randomized controlled trials including 608 patients, where three studies, including three treatments (amiodarone, lidocaine, and saline), contributed to the clinical outcome of atrial fibrillation, ventricular fibrillation, or any arrhythmia. Meta-analysis demonstrated that amiodarone can significantly reduce the incidence of POAF (RR, 0.39; 95%CI: 0.20, 0.77; P = 0.007, I2 = 0%) in patients undergoing on-pump CABG; there was no statistically significant influence on intra-operative atrial fibrillation, intra- and post-operative ventricular fibrillation, or any arrhythmia.

CONCLUSIONS

The current study suggests that intraoperative administration of intravenous amiodarone may be safe and effective in preventing POAF in patients undergoing on-pump CABG. More well-designed clinical trials are needed to validate this result.

Clinical Profiling and Biomarkers for Post-Operative Atrial Fibrillation Prediction in Patients Undergoing Cardiac Surgery

Post-operative atrial fibrillation (POAF) is the most common arrhythmia in the post-operative period after cardiac surgery. We aim to investigate the main clinical, local, and/or peripheral biochemical and molecular predictors for POAF in patients undergoing coronary and/or valve surgery. Between August 2020 and September 2022, consecutive patients undergoing cardiac surgery without previous history of AF were studied. Clinical variables, plasma, and biological tissues (epicardial and subcutaneous fat) were obtained before surgery. Pre-operative markers associated with inflammation, adiposity, atrial stretch, and fibrosis were analyzed on peripheral and local samples with multiplex assay and real-time PCR. Univariate and multivariate logistic regression analyses were performed in order to identify the main predictors for POAF. Patients were followed-up until hospital discharge. Out of 123 consecutive patients without prior AF, 43 (34.9%) developed POAF during hospitalization. The main predictors were cardiopulmonary bypass time (odds ratio (OR) 1.008 (95% confidence interval (CI), 1.002-1.013), p = 0.005), and plasma pre-operative orosomucoid levels (OR 1.008 (1.206-5.761). After studying differences regarding sex, orosomucoid was the best predictor for POAF in women (OR 2.639 (95% CI, 1.455-4.788), p = 0.027) but not in men. The results support the pre-operative inflammation pathway as a factor involved in the risk of POAF, mainly in women.

Biochemical Predictors of New-Onset Atrial Fibrillation after Ascending Aorta Replacement Surgery in Acute Type A Aortic Dissection Patients

Objective. This study aimed to determine the risk factors of new-onset postoperative atrial fibrillation after ascending aortic replacement in acute type A aortic dissection patients, with emphasis on biochemical parameters. Methods. From Jan 2020 to Dec 2021, a total of 435 acute type A aortic dissection patients who underwent ascending aortic replacement and without a history of atrial fibrillation were retrospectively analyzed in this study. Perioperative data of these patients were obtained from the hospital’s database. The 30-day follow-up was via telephone interviews. The multivariate regression analysis was used to identify risk factors that may be predictive of postoperative atrial fibrillation. Results. 218 (50.1%) patients experienced postoperative atrial fibrillation after ascending aorta replacement surgery. Older age (OR = 1.081 (1.059–1.104), $p<0.001$ ), higher total bile acid (OR = 1.064 (1.024–1.106), $p$  = 0.002), glucose (OR = 1.180 (1.038–1.342), $p$  = 0.012), and serum potassium (OR = 2.313 (1.078–4.960), $p$  = 0.031) were identified by multivariate regression analysis as risk factors of postoperative atrial fibrillation. The multivariate regression analysis prediction model incorporating these four factors had a good prediction effect (AUC = 0.769 (0.723–0.816), $p<0.001$ ). Conclusions. Older age, higher total bile acid, glucose, and serum potassium were risk factors of postoperative atrial fibrillation after ascending aortic replacement surgery in acute type A aortic dissection patients.

Risk and Subtypes of Stroke Following New-Onset Postoperative Atrial Fibrillation in Coronary Bypass Surgery: A Population-Based Cohort Study

Background New-onset postoperative atrial fibrillation (POAF) develops in approximately one-third of patients undergoing cardiac surgery and is associated with a higher incidence of ischemic stroke and increased mortality. However, it remains unknown to what extent ischemic stroke events in patients with POAF are cardioembolic and whether anticoagulant therapy is indicated. We investigated the long-term risk and pathogenesis of postoperative stroke in patients undergoing coronary artery bypass grafting experiencing POAF. Methods and Results This was a register-based cohort study. Data from the WDHR (Western Denmark Heart Registry) were linked with the DNPR (Danish National Patient Register), the Danish National Prescription Register, and the Cause of Death Register. All stroke diagnoses were verified, and ischemic stroke cases were subclassified according to pathogenesis. Furthermore, investigations of all-cause mortality and the use of anticoagulation medicine for the individual patient were performed. A total of 7813 patients without a preoperative history of atrial fibrillation underwent isolated coronary artery bypass grafting between January 1, 2010, and December 31, 2018, in Western Denmark. POAF was registered in 2049 (26.2%) patients, and a postoperative ischemic stroke was registered in 195 (2.5%) of the patients. After adjustment, there was no difference in the risk of ischemic stroke (hazard ratio [HR], 1.08 [95% CI, 0.74-1.56]) or all-cause mortality (HR, 1.09 [95% CI, 0.98-1.23]) between patients who developed POAF and non-POAF patients. Although not statistically significant, patients with POAF had a higher incidence rate (IR; per 1000 patient-years) of cardioembolic stroke (IR, 1 [95% CI, 0.6-1.6] versus IR, 0.5 [95% CI, 0.3-0.8]), whereas non-POAF patients had a higher incidence rate of large-artery occlusion stroke (IR, 1.1 [95% CI, 0.8-1.5] versus IR, 0.7 [95% CI, 0.4-1.4]). Early initiation of anticoagulation medicine was not associated with a lower risk of ischemic stroke. However, patients with POAF were more likely to die of cardiovascular causes than non-POAF patients (P<0.001). Conclusions We found no difference in the adjusted risk of postoperative stroke or all-cause mortality in POAF versus non-POAF patients. Patients with POAF after coronary artery bypass grafting presented with a higher, although not significant, proportion of ischemic strokes of the cardioembolic type.

Effectiveness of intra-operative topical amiodarone for prevention of postcardiac surgery new-onset atrial fibrillation: A review of current evidence

BACKGROUND

Postoperative atrial fibrillation (POAF) is one of the most common complications following cardiac surgery and is associated with increased morbidity. Intraoperative topical amiodarone application on epicardial tissue has been shown to reduce systemic concentrations while maintaining therapeutic myocardial concentrations, thereby, lowering the risk of extracardiac adverse effects associated with oral and intravenous amiodarone therapy. However, the efficacy and safety of topical amiodarone in preventing POAF is unclear.

OBJECTIVES

This study summarizes the clinical studies to-date that have investigated the efficacy and safety of topical amiodarone administration in preventing POAF following cardiac surgery.

METHODS

A database search was conducted using Medline, Embase, and Cochrane Library to identify relevant studies. Abstracts were screened and data were extracted from relevant full-text articles that met the inclusion and exclusion criteria.

RESULTS

The search returned four studies with variable findings on the effect of topical amiodarone therapy on the incidence of POAF, cardiac effects, extracardiac effects, and hospital length of stay.

CONCLUSION

Prophylactic topical application of amiodarone may be effective and safe for preventing post-operative new-onset atrial fibrillation. Further investigation is required to evaluate the efficacy and safety of topical amiodadrone therapy before it can be widely integrated into current practice.

Sacubitril/Valsartan Can Reduce Atrial Fibrillation Recurrence After Catheter Ablation in Patients with Persistent Atrial Fibrillation

PURPOSE

This study compared the effectiveness of sacubitril/valsartan (SV) vs. valsartan (V) for treating persistent atrial fibrillation (AF) after radio-frequency catheter ablation (RFCA).

METHODS

Patients with persistent AF who received RFCA were randomly assigned to the SV or V treatment group with the intervention lasting for 12 months. The primary outcome included any atrial arrhythmia episode lasting ≥ 30 s after a 3-month blanking period. The secondary outcome included any atrial arrhythmia episode lasting ≥ 24 h or requiring cardioversion after a 3-month blanking period. The H2FPEF score was used to assess the possibility of patients suffering from heart failure with preserved ejection fraction.

RESULTS

A total of 143 patients with persistent AF who received RFCA were randomized for the study, with 5 patients failing to follow-up. Among them, 29 (42%) out of 69 patients receiving V and 15 (21.7%) out of 69 patients receiving SV reached the primary endpoint (P < 0.001). A total of 26 (37.7%) out of 69 patients receiving V and 7 (10.1%) out of 69 patients receiving SV reached the secondary endpoint (P < 0.001). A decrease in the H2FPEF score after a 1-year follow-up seemed to be related to the recurrence of AF (OR, 0.065; 95% CI: 0.018-0.238, P < 0.001).

CONCLUSIONS

SV can decrease AF recurrence after catheter ablation in patients with persistent AF at the 1-year follow-up. The mechanism for this process may be related to the reduction in the H2FPEF score in patients with preserved ejection fraction heart failure.

Maintenance of Serum Potassium Levels ≥3.6 mEq/L Versus ≥4.5 mEq/L After Isolated Elective Coronary Artery Bypass Grafting and the Incidence of New-Onset Atrial Fibrillation: Pilot and Feasibility Study Results

OBJECTIVE

Serum potassium levels frequently are maintained at high levels (≥4.5 mEq/L) to prevent atrial fibrillation after cardiac surgery (AFACS), with limited evidence. Before undertaking a noninferiority randomized controlled trial to investigate the noninferiority of maintaining levels ≥3.6 mEq/L compared with this strategy, the authors wanted to assess the feasibility, acceptability, and safety of recruiting for such a trial.

DESIGN

Pilot and feasibility study of full trial protocol.

SETTING

Two university tertiary-care hospitals.

PARTICIPANTS

A total of 160 individuals undergoing first-time elective isolated coronary artery bypass grafting.

INTERVENTIONS

Randomization (1:1) to protocols aiming to maintain serum potassium at either ≥3.6 mEq/L or ≥4.5 mEq/L after arrival in the postoperative care facility and for 120 hours or until discharge from the hospital or AFACS occurred, whichever happened first.

MEASUREMENTS AND MAIN RESULTS

Primary outcomes: (1) whether it was possible to recruit and randomize 160 patients for six months (estimated 20% of those eligible); (2) maintaining supplementation protocol violation rate ≤10% (defined as potassium supplementation being inappropriately administered or withheld according to treatment allocation after a serum potassium measurement); and (3) retaining 28-day follow-up rates ≥90% after surgery. Between August 2017 and April 2018, 723 patients were screened and 160 (22%) were recruited. Potassium protocol violation rate = 9.8%. Follow-up rate at 28 days = 94.3%. Data on planned outcomes for the full trial also were collected.

CONCLUSIONS

It is feasible to recruit and randomize patients to a study assessing the impact of maintaining serum potassium concentrations at either ≥3.6 mEq/L or ≥4.5 mEq/L on the incidence of AFACS.

Postoperative Atrial Fibrillation After Cardiac Surgery: A Meta-Analysis

BACKGROUND

Postoperative atrial fibrillation (POAF) is common after cardiac surgery and linked to poorer short-term and long-term outcomes; however, conflicting evidence exists on stroke risk and how the index procedure affects outcomes. This study aims to provide a comprehensive review of the published outcomes of POAF after cardiac surgery, examined as a whole and by index procedure.

METHODS

A systematic review of POAF after cardiac surgery was conducted. Outcomes related to POAF were analyzed in a meta-analysis, and aggregate survival data were derived to examine long-term survival.

RESULTS

Sixty-one studies with 239,018 patients were identified, the majority (78.7%) undergoing coronary surgery. POAF occurred in 25.5% of patients and was associated with significantly higher rates of early mortality and stroke (odds ratio [OR], 1.74; P < .001; and OR, 2.21, P < .001, respectively) along with longer intensive care and overall hospital length of stay (mean difference 0.8 days, P = .008; and mean difference 2.8 days, P < .001, respectively). After a median of 6.6 years (range, 0.5-20 years), mortality and stroke remained significantly higher for those with POAF (OR, 1.57, P < .001; and OR, 1.81, P = .001). Pooled hazard ratio for long-term mortality was significantly higher for patients who underwent coronary surgery compared with isolated valve surgery.

CONCLUSIONS

POAF is common after cardiac surgery and is associated with significantly higher rates of both short-term and long-term stroke and mortality as well as increased hospital stay. Differences in hazard for long-term survival may be due to the underlying pathophysiological risk factors for POAF, which differ by surgical procedure.

Prophylaxis for postoperative atrial fibrillation: A quality initiative study exploring adherence to NICE guidance in a UK tertiary cardiothoracic intensive care unit

BACKGROUND

Acute onset atrial fibrillation is a common dysrhythmia experienced by patients following cardiac surgery which can often cause morbidity and extended hospital length of stay. The primary aim of the study was to explore adherence to National Institute for Health and Care Excellence (NICE) guidance which suggests the need for prophylaxis for postoperative atrial fibrillation (POAF). Secondary aims were to explore factors contributing to the development POAF and the impact of POAF on patient-centred outcomes.

METHODS

An analysis consisting of descriptive statistics and regression models was conducted using 138 patient's records who underwent cardiac surgery between January and March 2017.

RESULTS

We identified 83 (62%) patients on prophylactic rate control medications prior to surgery. During the study period, a total of 50 patients (36%) developed POAF, of which 28 were on prophylactic medication prior to surgery. Patients who developed POAF had significantly prolonged hospital length of stay compared to those who did not develop POAF.

CONCLUSION

Our study identified a significant proportion of patients not being offered prophylactic rate control prior to cardiac surgery. It is clear that poor patient outcomes are associated with the development of POAF and therefore there is an important need to ensure preventative measures are implemented in guidance relating to the management of these patients. Our results also suggest that tight management of clinical and physiological risk factors prior and during cardiac surgery may improve outcomes in this group of patients and could be considered in future enhanced recovery after cardiac surgery protocols.

Approach to the Patient: Perioperative Management of the Patient with Pheochromocytoma or Sympathetic Paraganglioma

Pheochromocytomas and sympathetic paraganglioma (PPGL) are rare chromaffin cell tumors originating in the adrenal medulla and sympathetic paraganglia, respectively, which share the capacity to synthesize and release catecholamines. The incidence of PPGL has increased in recent years. Surgical resection is the only curative treatment for PPGL. Management of patients with PPGL is complex and should be done by a specialized multidisciplinary team in centers with broad expertise. Surgical resection of a PPGL is a high-risk procedure for which optimal pretreatment with antihypertensive drugs is required in combination with state-of-the-art surgical procedures and anesthesiological techniques. In this article we discuss the underlying evidence and the pros and cons of presurgical medical preparation. Finally, the areas of uncertainty and controversies in this field are addressed.

Novel Oral Anticoagulants Compared to Warfarin for Postoperative Atrial Fibrillation After Isolated Coronary Artery Bypass Grafting

BACKGROUND

Postoperative atrial fibrillation (POAF) is common after cardiac surgery and contributes to short- and long-term morbidity, particularly thromboembolism. Anticoagulation for sustained or recurrent POAF is suggested to reduce thromboembolism. Novel oral anticoagulants may present a safe alternative to warfarin with further benefits including shorter hospital length of stay and better patient convenience.

METHODS

A retrospective analysis was performed on all isolated cases of coronary artery surgery (CABG) at our institution between January 2015 and December 2018, totalling 960 patients. Rates of POAF were examined with particular focus on preoperative factors, postoperative outcomes, and anticoagulation practices.

RESULTS

The incidence of POAF was 31.8% (305 patients) and was higher in older patients (67.6±9.4 yrs vs 63.0±10.7 yrs, p<0.001), those with a history of cerebrovascular disease (14.6% vs 8.7%, p=0.02), those with higher CHADS-VASc scores (2.5±1.3 vs 2.8±1.3, p<0.001) those who had a postoperative return to theatre (2.6% vs 0.8%, p=0.002), and those with new renal failure (4.9% vs 1.8%, p=0.02). Off-pump surgery was associated with lower incidence of POAF (29.8% vs 37.1%, p=0.03). Patients who developed POAF had significantly longer admissions than those without (12.6±10.6 days vs 9.3±16.3 days, p<0.001). In total, 106 patients (11.0%) went home anticoagulated; 77 (72.6%) on warfarin and 29 (27.4% on a NOAC). Readmission for bleeding was higher in patients on anticoagulation (1.0% vs 0.0%, p=0.02), but did not drive readmission for pericardial effusion (0.3% vs 0.6%, p=0.55). No bleeding complications occurred in patients who were discharged on a NOAC. Overall mortality at median of 2 years was 1.8% (17 patients) and no mortality occurred in any patient discharged on anticoagulation.

CONCLUSION

Postoperative atrial fibrillation is a common adverse event and is linked to higher preoperative and postoperative morbidity. Anticoagulation may be safely started in these patients and use of novel anticoagulation does not appear to increase postoperative complications, although overall numbers are low.

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.

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.

Association between potassium concentrations, variability and supplementation, and in-hospital mortality in ICU patients: a retrospective analysis

BACKGROUND

Serum potassium concentrations are commonly between 3.5 and 5.0 mmol/l. Standardised protocols for potassium range and supplementation in the ICU are lacking. The purpose of this retrospective analysis of ICU patients was to investigate potassium concentrations, variability and supplementation, and their association with in-hospital mortality.

METHODS

ICU patients ≥ 18 years, with ≥ 2 serum potassium values, treated at the Charité - Universitätsmedizin Berlin between 2006 and 2018 were eligible for inclusion. We categorised into groups of mean potassium concentrations: < 3.0, 3.0-3.5, > 3.5-4.0, > 4.0-4.5, > 4.5-5.0, > 5.0-5.5, > 5.5 mmol/l and potassium variability: 1st, 2nd and ≥ 3rd standard deviation (SD). We analysed the association between the particular groups and in-hospital mortality and performed binary logistic regression analysis. Survival curves were performed according to Kaplan-Meier and tested by Log-Rank. In a subanalysis, the association between potassium supplementation and in-hospital mortality was investigated.

RESULTS

In 53,248 ICU patients with 1,337,742 potassium values, the lowest mortality (3.7%) was observed in patients with mean potassium concentrations between > 3.5 and 4.0 mmol/l and a low potassium variability within the 1st SD. Binary logistic regression confirmed these results. In a subanalysis of 22,406 ICU patients (ICU admission: 2013-2018), 12,892 (57.5%) received oral and/or intravenous potassium supplementation. Potassium supplementation was associated with an increase in in-hospital mortality in potassium categories from > 3.5 to 4.5 mmol/l and in the 1st, 2nd and ≥ 3rd SD (p < 0.001 each).

CONCLUSIONS

ICU patients may benefit from a target range between 3.5 and 4.0 mmol/l and a minimal potassium variability. Clear potassium target ranges have to be determined. Criteria for widely applied potassium supplementation should be critically discussed. Trial registration German Clinical Trials Register, DRKS00016411. Retrospectively registered 11 January 2019, http://www.drks.de/DRKS00016411.

New-Onset Atrial Fibrillation in Adult Patients After Cardiac Surgery

Purpose of Review

An overview of recent literature regarding pathophysiology, risk factors, prophylaxis, and treatment of new-onset atrial fibrillation (AF) in post-cardiac surgical patients.

Recent Findings

AF is the most frequent adverse event after cardiac surgery with significant associated morbidity, mortality, and financial cost. Its causes are multifactorial, and models to stratify patients into risk categories are progressing but a consistent, evidence-based system has not yet been developed. Pharmacologic and surgical interventions to prevent and treat this complication have been an area of ongoing research and recent societal guidelines reflect this.

Summary

Inconsistencies remain surrounding how to best identify higher-risk AF patients, which interventions should be used to prevent and treat AF, and which patient groups should receive these interventions. The evidence for these available strategies and their place in contemporary guidelines are summarized.

Postoperative Atrial Fibrillation Among Patients Undergoing Isolated Coronary Artery Bypass Grafting

Introduction Postoperative atrial fibrillation (AF) is the commonest of all the known cardiac arrhythmias after cardiac surgery. The postoperative AF has both short- and long-term adverse impacts on patients, like prolonged intensive care unit (ICU) stay, increased frequency of reoperations, myocardial infarction, increased use of inotropes, and intra-aortic balloon pump (IABP). There is a paucity of data regarding the postoperative AF after isolated coronary artery bypass grafting (CABG) and its risk factors in our geographic location. Therefore, the aim of this study was to determine the frequency of postoperative atrial fibrillation among patients undergoing isolated CABG at a tertiary care hospital of Karachi, Pakistan. Methods This prospective observational study was conducted on 163 consecutively selected patients undergoing first time isolated CABG at the Department of Cardiothoracic Surgery, Aga Khan University Hospital, Karachi. Patients with redo-sternotomy, preoperative atrial fibrillation and with other cardiac pathology were excluded from the study. Postoperative AF was defined in the patients with postoperative 12-lead electrocardiographic (ECG) finding of absence of P waves, replaced by unorganized electrical activity and irregular R-R intervals. Data analysis was carried out using IBM SPSS Statistics for Windows, Version 21.0 (IBM Corp., Armonk, NY, USA). Results A total of 163 patients were enrolled with the mean age of 58.66 ± 9.77 years ranging between 40 and 85 years with male predominance of 81% (132). The most common comorbidity was hypertension in about 68.1% (111), followed by diabetes mellitus in 54.6% (89) patients. Postoperative AF was observed in 42 (25.8%) patients. Most of the patients who developed postoperative AF, were overweight with mean body mass index (BMI) of 27.04 ± 4.85 kg/m2, 76.2% (32) had a history of hypertension, diabetes mellitus was associated with 33.3% (14) patients with postoperative AF and 50.0% (21) of them were smokers. Distribution of coronary artery disease in patients with postoperative AF was observed as three vessels coronary artery disease (3VCAD) in 83.3% (35), two-vessel coronary artery disease (2VCAD) was present in 7.1% (three), and rest of 9.5% (four) patients had single-vessel coronary artery disease (SVCAD). Conclusion The frequency of postoperative atrial fibrillation in our study was found to be 25.9% which is comparable to world literature. An important finding that comes through this study is a younger population undergoing CABG, which raises the possibility of early manifestation of ischemic heart disease in our region. This, however, needs further investigation. We were unable to point out the factors predictive of postoperative AF; studies with larger sample size would help in that regard.

Postoperative atrial fibrillation is associated with delayed early rehabilitation after heart valve surgery: a multicenter study

OBJECTIVE

Postoperative atrial fibrillation (POAF) is a common complication after cardiac surgery. The aim of this multicenter study was to determine the relationship between POAF and patients' progress in early rehabilitation after heart valve surgery.

METHODS

We enrolled 302 patients (mean age, 69±10 years) who had undergone heart valve surgery. POAF was monitored using continuous electrocardiogram telemetry, and the Short Physical Performance Battery (SPPB) was used to assess lower-extremity function before surgery and at the time of discharge. Progress in early rehabilitation was evaluated by the duration from the surgery to independent walking. We determined factors associated delayed early rehabilitation and evaluated the interplay of POAF and delayed early rehabilitation in increasing the risk of decline in lower-extremity function from preoperatively to hospital discharge.

RESULTS

Multivariate analysis determined POAF to be independent predictors of delayed early rehabilitation after heart valve surgery (OR: 3.906, P = .01). The association between delayed early rehabilitation and decline in lower extremity function was stronger in patients with POAF (OR: 2.73, P = .041) than in those without (OR: 2.22, P = .052).

CONCLUSIONS

POAF was clinical predictors of delayed early rehabilitation in patients undergoing heart valve surgery. The combination of POAF with delayed early rehabilitation conferred a high risk of decline in lower-extremity function during hospitalization.

Comparison of the Efficacy of Oral versus Intravascular Magnesium in the Prevention of Hypomagnesemia and Arrhythmia after CABG

Objective

Cardiac arrhythmias are a common challenge following open-heart surgeries. Hypomagnesemia is believed to be correlated with this condition. Prophylactic intravenous magnesium supplementation has been practiced for a long time in patients undergoing CABG. This study was designed in an attempt to compare the efficacy of oral versus intravenous routes in the prevention of hypomagnesemia and arrhythmia.

Methods

In this interventional clinical study, 82 patients were randomly assigned to 2 groups. All patients were evaluated for baseline serum magnesium level and arrhythmias. One group received 1,600 mg of oral magnesium hydroxide through nasogastric (NG) tube prior to surgery, while the other group received 2 g of magnesium sulfate during the induction of anesthesia. The serum magnesium level was monitored for 48 hours after the operation. The difference in preoperative hypomagnesemia was non-significant (Sig: 0.576).

Results

During the operation, the serum magnesium level peaked around 4 mg/dL, and no hypomagnesemia was detected in any patient. Although the curve of oral group declined parallel and below that of intravenous (IV) group, no significant differences were detected during postoperative monitoring. In addition, a prevalence of arrhythmia of 13.9% and 6.5% was noticed in IV and oral groups, respectively (OR: 0.428).

Conclusion

Providing 1,600 mg of oral magnesium supplement to patients is as effective as 2,000 mg of magnesium sulfate IV in preventing hypomagnesemia and arrhythmia after CABG. Thus, the authors introduce this treatment regimen as a promising and cost-effective method.

Follow-up and management of valvular heart disease patients with prosthetic valve: a clinical practice guideline for Indian scenario

PURPOSE

Valvular heart disease (VHD) patients after prosthetic valve implantation are at risk of thromboembolic events. Follow-up care of patients with prosthetic valve has a paramount role in reducing the morbidity and mortality. Currently, in India, there is quintessential need to stream line the follow-up care of prosthetic valve patients. This mandates the development of a consensus guideline for the antithrombotic therapy in VHD patients post prosthetic valve implantation.

METHODS

A national level panel was constituted comprising 13 leading cardio care experts in India who thoroughly reviewed the up to date literature, formulated the recommendations, and developed the consensus document. Later on, extensive discussions were held on this draft and the recommendations in 8 regional meetings involving 79 additional experts from the cardio care in India, to arrive at a consensus. The final consensus document is developed relying on the available evidence and/or majority consensus from all the meetings.

RESULTS

The panel recommended vitamin K antagonist (VKA) therapy with individualized target international normalized ratio (INR) in VHD patients after prosthetic valve implantation. The panel opined that management of prosthetic valve complications should be personalized on the basis of type of complications. In addition, the panel recommends to distinguish individuals with various co-morbidities and attend them appropriately.

CONCLUSIONS

Anticoagulant therapy with VKA seems to be an effective option post prosthetic valve implantation in VHD patients. However, the role for non-VKA oral therapy in prosthetic valve patients and the safety and efficacy of novel oral anticoagulants in patients with bioprosthetic valve need to be studied extensively.

Post-operative left atrial volume index is a predictor of the occurrence of permanent atrial fibrillation after mitral valve surgery in patients who undergo mitral valve surgery

Background

Atrial fibrillation (AF) can occur even after the correction of mitral valve (MV) pathology in patients who have pre-operative sinus rhythm and undergo MV surgery. However, the factors associated with the occurrence of AF after MV surgery are still unclear. The aim of this retrospective study was to investigate the factors determining the occurrence of permanent AF after MV surgery in patients with preoperative sinus rhythm who underwent MV surgery.

Methods

Four hundred and forty-two patients (mean age 46 ± 12, 190 men) who underwent MV surgery and sinus rhythm were investigated retrospectively. Transthoracic echocardiography was performed before and after MV surgery at the time of dismissal.

Results

Permanent post-operative AF occurred in 81 (18%) patients even after successful MV surgery and preoperative sinus rhythm. It was more common in rheumatic etiology, a presence of mitral stenosis, lower pre- and post-operative left ventricular ejection fraction, higher post-operative mean diastolic pressure gradient across mitral prosthesis, larger post-operative left atrial volume index (LAVI) and lesser degrees of reduction in LAVI after surgery. In multiple regression analysis, post-operative LAVI was found to be an independent predictor for occurrence of AF. Post-operative LAVI > 39 ml/m2 was the cut-off value for best prediction of new onset permanent AF (sensitivity: 79%, AUC: 0.762, SE: 0.051, p < 0.001).

Conclusion

New-onset permanent post-operative AF is not uncommon, even after successful MV surgery despite pre-operative sinus rhythm. Larger post-operative LAVI was an independent predictor for the occurrence of AF.

The impact of maintaining serum potassium ≥3.6 mEq/L vs ≥4.5 mEq/L on the incidence of new-onset atrial fibrillation in the first 120 hours after isolated elective coronary artery bypass grafting - study protocol for a randomised feasibility trial for the proposed Tight K randomized non-inferiority trial

Background

Atrial fibrillation (AF) occurs in approximately one in three patients after cardiac surgery, and is associated with increased short-term and long-term mortality, intensive care unit (ICU) and hospital stay, and increased cost of care. In an attempt to reduce AF incidence in these patients, serum potassium (K+) levels are commonly maintained at the high end of normal (4.5–5.5 mEq/L). However, such potassium supplementation is without proven benefit, and is not without negative consequences. It carries clinical risk, negatively impacts patient experience and is both time-consuming and costly. This protocol describes a randomised controlled pilot trial to assess the feasibility of a proposed randomised non-inferiority trial to investigate the impact of maintaining serum potassium ≥ 3.6 mEq/L vs ≥ 4.5 mEq/L on the incidence of new-onset atrial fibrillation in the first 120 hours after isolated elective coronary artery bypass grafting.

Methods

Design: this is a randomized feasibility trial as a pilot for a randomized non-inferiority trial. Participants: are 160 patients undergoing isolated coronary artery bypass grafting at two centres. Allocation: patients will be randomized (1:1) to protocols aiming to maintain serum potassium at either ≥ 3.6 mEq/L (“relaxed control”) or ≥ 4.5 mEq/L (“tight control”). Primary analytic aim: was to assess the feasibility and acceptability of planning and delivering the intervention and trial methods to inform a full-scale non-inferiority trial. Outcome: the primary indicative efficacy outcome measures being field-tested are feasibility of participant recruitment and randomization, maintaining a protocol violation rate < 10%, and retaining 90% patient follow up 28 days after surgery. The primary clinical outcome measure of the future full “Tight K Study” will be incidence of AF after cardiac surgery.

Discussion

The Tight K Pilot will assess the feasibility of conducting the full trial, which is intended to confirm or refute the efficacy of current potassium management in preventing AF after cardiac surgery.

Trial registration

ClinicalTrials.gov, NCT03195647. Registered on 23 May 2017. Last updated 19June 2017.

Electronic supplementary material

The online version of this article (doi:10.1186/s13063-017-2349-x) contains supplementary material, which is available to authorized users.

Postoperative atrial fibrillation: Target for stroke prevention?

Purpose

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

Method

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

Findings

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

Conclusion

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

New-Onset Atrial Fibrillation in the Critically Ill

OBJECTIVE

To determine the association of new-onset atrial fibrillation with outcomes, including ICU length of stay and survival.

DESIGN

Retrospective cohort of ICU admissions. We found atrial fibrillation using automated detection (≥ 90 s in 30 min) and classed as new-onset if there was no prior diagnosis of atrial fibrillation. We identified determinants of new-onset atrial fibrillation and, using propensity matching, characterized its impact on outcomes.

SETTING

Tertiary care academic center.

PATIENTS

A total of 8,356 consecutive adult admissions to either the medical or surgical/trauma/burn ICU with available continuous electrocardiogram data.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

From 74 patient-years of every 15-minute observations, we detected atrial fibrillation in 1,610 admissions (19%), with median burden less than 2%. Most atrial fibrillation was paroxysmal; less than 2% of admissions were always in atrial fibrillation. New-onset atrial fibrillation was subclinical or went undocumented in 626, or 8% of all ICU admissions. Advanced age, acute respiratory failure, and sepsis were the strongest predictors of new-onset atrial fibrillation. In propensity-adjusted regression analyses, clinical new-onset atrial fibrillation was associated with increased hospital mortality (odds ratio, 1.63; 95% CI, 1.01-2.63) and longer length of stay (2.25 d; CI, 0.58-3.92). New-onset atrial fibrillation was not associated with survival after hospital discharge (hazard ratio, 0.99; 95% CI, 0.76-1.28 and hazard ratio, 1.11; 95% CI, 0.67-1.83, respectively, for subclinical and clinical new-onset atrial fibrillation).

CONCLUSIONS

Automated analysis of continuous electrocardiogram heart rate dynamics detects new-onset atrial fibrillation in many ICU patients. Though often transient and frequently unrecognized, new-onset atrial fibrillation is associated with poor hospital outcomes.

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

BACKGROUND

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

MATERIALS AND METHODS

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

RESULTS

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

CONCLUSIONS

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

Systematic review and meta-analysis of randomized controlled trials assessing safety and efficacy of posterior pericardial drainage in patients undergoing heart surgery

OBJECTIVES

To investigate the potential beneficial effects of posterior pericardial drainage in patients undergoing heart surgery.

METHODS

Multiple online databases and relevant congress proceedings were screened for randomized controlled trials assessing the efficacy and safety of posterior pericardial drainage, defined as posterior pericardiotomy incision, chest tube to posterior pericardium, or both. Primary endpoint was in-hospital/30 days' cardiac tamponade. Secondary endpoints comprised death or cardiac arrest, early and late pericardial effusion, postoperative atrial fibrillation (POAF), acute kidney injury, pulmonary complications, and length of hospital stay.

RESULTS

Nineteen randomized controlled trials that enrolled 3425 patients were included. Posterior pericardial drainage was associated with a significant 90% reduction of the odds of cardiac tamponade compared with the control group: odds ratio (95% confidence interval) 0.13 (0.07-0.25); P < .001. The corresponding event rates were 0.42% versus 4.95%. The odds of early and late pericardial effusion were reduced significantly in the intervention arm: 0.20 (0.11-0.36); P < .001 and 0.05 (0.02-0.10); P < .001, respectively. Posterior pericardial drainage significantly reduced the odds of POAF by 58% (P < .001) and was associated with significantly shortened (by nearly 1 day) overall length of hospital stay (P < .001). Reductions in postoperative complications translated into significantly reduced odds of death or cardiac arrest (P = .03) and numerically lower odds of acute kidney injury (P = .08).

CONCLUSIONS

Posterior pericardial drainage is safe and simple technique that significantly reduces not only the prevalence of early pericardial effusion and POAF but also late pericardial effusion and cardiac tamponade. These benefits, in turn, translate into improved survival after heart surgery.

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.

Long-term outcomes of catheter ablation of atrial fibrillation post-cardiac valve replacement

OBJECTIVE

The long-term outcomes of catheter ablation of atrial fibrillation (AF) developing post-cardiac valve replacement (VR) remain undefined.

METHODS AND RESULTS

Eighty-nine post-VR patients with AF (44% longstanding persistent AF, LSP-AF) were enrolled. Cumulative success rate of circumferential pulmonary vein ablation (CPVA for paroxysmal AF) and bidirectional block of lines and disappearance of complex fractionated atrial electrograms (CFAEs for persistent and LSP-AF) as index and repeat procedural endpoints reached 57% (mean, 1.3 procedures) during the first year, and dropped to 42% at median follow-up of 40months (range, 24-70months) for multiple procedures (mean, 1.6±0.9 [1-5]); incidence of procedural complications was similar to that of conventional procedures. In multivariate analysis, larger right atrium (RA, 9.40 [2.64-33.36]; P=0.001) and rheumatic valvular disease etiology (OR, 5.49 [95% CI, 1.26-23.96]; P=0.023) were significant independent predictors of recurrent atrial tachyarrhythmia (ATa); in contrast, long-term freedom from ATa was comparable between single and double valve replacement groups (42.1% vs. 43.7%, P=0.880), or mechanical and bioprosthetic valves groups (41.7% vs. 50.0%, P=0.620).

CONCLUSION

In this single-center prospective study, treatment of post-VR AF with commonly used ablation strategies including CPVA and linear and CFAE ablation had limited long-term success, with ATa recurrence risk appearing higher in the setting of RA enlargement and rheumatic valvular disease and unrelated to valves characteristics.

Incidence and impact of postoperative atrial fibrillation after minimally invasive esophagectomy

Atrial fibrillation (AF) following open esophagectomy has been associated with increased rates of pulmonary and anastomotic complications, and mortality. This study seeks to evaluate effects of AF after minimally invasive esophagectomy (MIE). A retrospective review of patients consecutively treated with MIE for esophageal carcinoma, dysplasia. and benign disease from November 2006 to November 2011 was performed. One hundred twenty-one patients underwent MIE. Median age was 65 years (range 26-88) with 85% being male. Thirty-eight (31.4%) patients developed AF postoperatively. Of these 38 patients, 7 (18.4%) had known AF preoperatively. Patients with postoperative AF were significantly older than those without postoperative AF (68.7 vs. 62.8 years, P = 0.008) and more likely to be male (94.7% vs. 80.7%, P = 0.04). Neoadjuvant chemoradiation showed a trend toward increased risk of AF (73.7% vs 56.6%, P = 0.07). Sixty-day mortality was 2 of 38 (5.3%) in patients with AF and 4 of 83 (6.0%) in the no AF cohort (P = 1.00). The group with AF had increased length of hospitalization (13.4 days vs. 10.6 days P = 0.02). No significant differences in rates of pneumonia (31.6% vs. 21.7% P = 0.24), stricture (13.2% vs. 26.5% P = 0.10), or leak requiring return to operating room (13.2% vs. 8.4% P = 0.51) were noted between groups. We did not find an increased rate of AF in our MIE cohort compared with prior reported rates in open esophagectomy populations. AF did result in an increased length of stay but was not a predictor of other short-term morbidities including anastomotic leak, pulmonary complications, stenosis, or 60-day mortality.

Clinical effects of leukofiltration and surface modification on post-cardiopulmonary bypass atrial fibrillation in different risk cohorts

Objective. A manifestation of inflammatory injury to the heart, atrial fibrillation (AF), ranks among the most frequent and potentially life-threatening post-operative complications. Methods. In a prospective randomized study, 120 patients undergoing CABG were allocated into two groups (N = 60): Group 1- Polymethoxyethylacry late-coated circuits + Leukocyte filters (Terumo,USA); Group 2: Control:Uncoated circuits (Terumo,USA). Each group was further divided into three subgroups (N = 20) with respect to low (Euroscore 0—2), medium (3—5) and high (6+) risk patients. Results. Serum IL-2 levels were significantly lower in the study group at T4 and T5 (p < 0.01). C3a levels showed significant differences in the leukofiltrated group at T4 and T5 (p < 0.05). CPKMB levels demonstrated well-preserved myocardium in the leukofiltration group, post-operatively. AF incidence was 10% (2 patients) in the study and 35% (7 patients) in the control cohorts (p < 0.05). Phagocytic capacity on fibers in filtered patients was significantly lower. Conclusion: Leukofiltration and coating significantly reduce the incidence, ventricular rate, and duration of AF after CABG via modulation of systemic inflammatory response and platelet preservation in high risk groups. Perfusion (2007) 22, 279—288.

Is magnesium sulfate friend or foe of off-pump coronary artery bypass surgery?

Magnesium sulfate is often used empirically in cardiac surgical settings. Magnesium sulfate may cause platelet dysfunction leading to bleeding complication. This editorial commentary discusses the published study of intra-operative use of magnesium sulfate during off-pump coronary artery bypass grafting published in this issue of Indian Heart Journal.