Frequency Of Postoperative Atrial Fibrillation Research Articles

Age-related Increase in Incidence of Postoperative Atrial Fibrillation Following Coronary Artery Bypass Grafting (CABG) Surgery

Atrial Fibrillation (AF) is one of the common arrhythmias after coronary artery bypass grafting (CABG) mostly occurs within 2 to 4 days. The advanced age is one of the important risk factors. Objective: To determine the frequency of Postoperative Atrial Fibrillation (POAF) in patients age between 30-65 years who underwent elective CABG Surgery. Methods: One hundred and thirty-seven Adult patients of either sex between age of 30 to 65 years with three vessel coronary artery disease underwent elective CABG surgery were included in our study. It was descriptive cross-sectional study, conducted at Tabba Heart Institute, Karachi, from December 2021 to June 2022. Postoperatively daily EKG was performed for the evidence of POAF. Results: One hundred and thirty-seven patients, between age group of 30-65 years among them 115 (84%) were male & 22 (16%) were females with mean age of patients 55.91years were included in our study. Post-Operative Atrial Fibrillation (POAF) was observed in 12.4%, out of whom 76.5% were male while 23.5% were female. The mean day of onset of POAF was 2.38 days. The relationship between increasing age groups and AF was found to be statistically significant i.e. p-value 0.04. There is significant difference between age groups and maximum incidence of POAF were found in above 60 years. Conclusions: In our study frequency of POAF was found in 12.4 %with mean age of participants was found to be 55.91 ± 6.5 years. Objective: To determine the frequency of Postoperative Atrial Fibrillation (POAF) in patients age between 30-65 years who underwent elective CABG Surgery. Methodology: One hundred and thirty seven Adult patients of either sex between age of 30 to 65 years with three vessel coronary artery disease underwent elective CABG surgery were included in our study. It was descriptive cross-sectional study, conducted at Tabba Heart Institute, Karachi, from December 2021 to June 2022. Postoperatively daily EKG was performed for the evidence of POAF. RESULT: One hundred and thirty seven patients, between age group of 30-65 years among them 115 (84%) were male & 22 (16%) were females with mean age of patients 55.91years were included in our study. Post-Operative Atrial Fibrillation (POAF) was observed in 12.4%, out of whom 76.5% were male while 23.5% were female. The mean day of onset of POAF was 2.38 days. The relationship between increasing age groups and AF was found to be statistically significant i.e. p-value 0.04. There is significant difference between age groups and maximum incidence of POAF were found in above 60 years. CONCLUSION: In our study frequency of POAF was found in 12.4 %with mean age of participants was found to be 55.91 + 6.5 years.

Postoperative Atrial Fibrillation After Coronary Bypass Surgery In Patients Having Pre-Operative Hypoalbuminemia.

Hypoalbuminemia commonly occurs in cardiac patients, especially in elderly patients and those with chronic congestive heart failure, and it has been associated with adverse events such as atrial fibrillation. The study aimed to determine the incidence of postoperative atrial fibrillation (POAF) in patients undergoing coronary bypass surgery (CABG) with pre-operative hypoalbuminemia in a major cardiac surgery institute in Karachi, Pakistan. This descriptive cross-sectional study included patients of any gender, aged between 30-80 years, who underwent CABG surgery and had hypoalbuminemia at the time of pre-operative assessment. Hypoalbuminemia was defined as a serum albumin level less than 3.8 mg/dL (normal range: 3.8-4.5 mg/dL). We recorded routine daily 12-lead ECGs and monitored the occurrence of POAF within 72 hours of surgery. A total of 144 patients were included in the study, of which 77.8% (112) were male, and the mean age was 58.1±8.4 years. The average serum albumin levels before surgery were 3.5±0.2 mg/dL. The majority of patients, 71.5% (103), had three-vessel disease (3VD), and 20.8% (30) had 3VD with left main (LM) disease. Hypertension was observed in 70.1% (101) of the patients, diabetes in 52.1% (75), and prolonged CBP time in 61.8% (89). The frequency of POAF was 10.4% (15), and it was significantly higher in non-hypertensive and non-diabetic patients, with a crude odds ratio of 4.19 [1.39-12.65] and 8.47 [1.84-39.09], respectively. The study found that approximately one in every ten patients undergoing CABG experienced POAF. Surprisingly, the rate of POAF was higher among non-hypertensive and non-diabetic patients.

The Predictive Role of Small Airway Dysfunction in Postoperative Atrial Fibrillation After Isolated Coronary Artery Bypass Surgery.

Atrial fibrillation is the most common arrhythmia following coronary artery bypass graft surgery. The relationship between impaired lung function and atrial fibrillation has been described previously. We aimed to evaluate the prognostic influence of small airway function on predicting postoperative atrial fibrillation undergoing isolated coronary artery bypass graft surgery (CABG). We retrospectively analyzed 283 patients who underwent isolated CABG at our institution between January 2020 and August 2020. The patients were divided into 2 groups according to the development of postoperative atrial fibrillation. Demographic characteristics of the patients were recorded; spirometry was performed for each patient before surgery. Small airway function was determined by forced mid-expiratory flow (forced expiratory flow 25%-75%) values measured by spirometry. Propensity score matching was applied to ensure a balanced distribution of demographic data between the 2 groups. The frequency of postoperative atrial fibrillation was 30.7% in our patient population. After propensity matching, forced expiratory volume in 1 second/forced vital capacity % [80.6 (73.8-87.8) vs. 76.3 (66.7-81.6), P = 0.006] and forced expiratory flow 25%-75% (87.4 ± 14.2 vs. 75.2 ± 15.8, P = 0.001) were significantly lower in postoperative atrial fibrillation group. In multivariate analysis, white blood cell count, left ventricular ejection fraction, cross-clamp time, and forced expiratory flow 25%-75% were found to be independent predictors of postoperative atrial fibrillation development after isolated CABG. In the receiver operating characteristic curve analysis, forced expiratory flow 25%-75% with an optimal threshold value of 81% could detect the presence of postoperative atrial fibrillation with 63.8% sensitivity and 70.1% specificity. Our study demonstrated that small airway obstruction, as indicated by forced expiratory flow 25%-75% in spirometry, can be a simple predictive tool for the development of postoperative atrial fibrillation in patients undergoing isolated CABG.

Pre-operative N-Acetyl Cysteine for Prevention of Atrial Fibrillation After CABG Surgery in Pakistan

Objective: To determine the effect of NAC in prevention of post-operative atrial fibrillation in patients undergoing CABG.
 Study Design: Quasi experimental study.
 Place and Duration of Study: Adult Cardiac Intensive Care Unit, Armed Forces Institute of Cardiology & National Institute of Heart Diseases (AFIC&NIHD) Rawalpindi during 6 months.
 Methodology: 146 patients of both gender undergoing elective CABG were included in the study, having age between 30-70 years. However, any patient with history of arrhythmia including AF, thyroid dysfunction, ejection fraction less than 25%, any valvular lesion, dilated left atrium, dilated left ventricle, dilated right atrium, dilated right ventricle or having right atrial tear during surgery were excluded from the study. By using non-probability consecutive sampling, patients were divided into two groups by using envelope method. One group was given standard treatment (control group) while other group was named as NAC group (experimental group). Data analysis was performed using SPSS version-23. Descriptive statistics were reported as Mean±SD. Categorical variables were reported as frequency and percentage. Chi square test and T-test was used to determine association between different variables.
 Results: A total of 146 patients with mean age 55.27±7.3 yrs. 127(87%) were male and 19(13%) were females. 28(19.2%) patients had atrial fibrillation while 11(7.5%) patients had ventricular premature contractions (VPC). There was no statistically significant difference between ages (p=0.784), gender (p=0.461), AF (p=0.207) and VPC (p=0.347). Out of 73 (50%) patients from each group; the mean age of NAC group was 55.41±7.3 yrs and of control group was 55.08±7.1 yrs (p=0.784). Gender wise distribution of NAC group had 8(11%) females and 65(89%) males while in control group 11(15%) females and 62(85%) were males. AF was found to be 11(15%) and 17(23.3%) in NAC and control group respectively. In NAC group, VPC was 4 (5.5%) and in control group it was 66 (90.4%).
 Conclusion: This study shows that NAC decreases the frequency of post-operative atrial fibrillation and ventricular premature contractions, but the decrease is statistically insignificant in Pakistani population. However, keeping in view other beneficial effects of NAC, we would recommend more studies on this subject in Pakistani population.

Colchicine for Prevention of Atrial Fibrillation after Cardiac Surgery in the Early Postoperative Period.

Background. Postoperative atrial fibrillation (POAF) is a common complication of cardiac surgery. It has been proven to be associated with an increase in the incidence of early complications and mortality, an increase in the rate of hospital stay duration, and economic costs of their treatment. One of the pharmaceutical drugs recommended by the American College of Cardiology (ACC)/American Heart Association (AHA) for preventing POAF is colchicine (class IIB). However, the results of research on the efficacy and safety of colchicine are ambiguous and, consequently, require further study. Objective. Evaluating the efficacy of short-term colchicine administration in the prevention of POAF in patients after open-heart surgery. Materials and methods. Double-blind, randomized, placebo-controlled clinical trial. The subjects were randomly assigned to two groups: treatment group (n = 50) with subjects receiving 1 mg of colchicine 24 h before the surgery, as well as on days 2, 3, 4, and 5 in the postoperative period; and the control group (n = 51), receiving placebo on the same schedule. The primary endpoint was the frequency of POAF in both groups within 7 days after surgery. Results. The study included 101 patients (82 men, 19 women). Baseline clinical, laboratory, instrumental, and intraoperative data did not differ statistically significantly between the groups. POAF was detected in 9 patients (18%) of the treatment group and 15 subjects (29.4%) of the control group, which had no statistical significance (odds ratio, OR 0.527; 95% Cl 0.206–1.349; p = 0.178). No statistically significant differences were revealed for most secondary endpoints, as well as between the groups for all laboratory parameters. There were statistically significant differences between the groups solely in the frequency of diarrhea: 16 (32%) patients in the treatment group and 6 (11.8%) subjects in the control group (OR 3.529; 95% Cl 1.249–9.972; p = 0.010). Conclusions. We did not detect any statistical differences between the groups in terms of primary endpoints, which could be due to the insufficient volume of the sample of the study. However, we detected some trends of statistical differences among the groups in terms of some parameters. Clinical Trials Registration. ClinicalTrials. Unique identifier: NCT04224545.

A novel electrocardiographic parameter for the prediction of atrial fibrillation after coronary artery bypass graft surgery "P wave peak time".

Patients with postoperative atrial fibrillation (POAF) have increased risk of both short- and long-term mortality and morbidity; therefore, prediction of POAF is crucial in the preoperative period of the patients undergoing coronary artery bypass graft surgery. Electrocardiography (ECG) is the simplest and cost-effective tool in the preoperative workup of the patients for the prediction of POAF. A newly defined ECG parameter P wave peak time (PWPT) has been shown as a marker of atrial fibrillation development in non-surgical patients and we investigated its role in patients undergoing cardiac surgery. A total of 327 patients undergoing isolated or combined cardiac surgery were involved and the primary endpoint was defined as the development of POAF. The study population was divided into two groups based on the presence or absence of POAF. Groups were compared for both standard P wave parameters and for PWPT on surface ECG. The predictors of POAF were assessed by multivariate regression analysis. The frequency of POAF was 20.4% (n = 67). P wave peak time in leads D2 (65.1 ± 11.8 vs 57.2 ± 10, p < 0.01) and V1 (57.8 ± 18 vs 44.8 ± 12.3, p < 0.01) were longer in patients with POAF. In multivariate regression analysis, PWPT in leads DII and V1 were independent predictors of POAF (OR: 1.11, 95%CI: 1.02-1.21, p = 0.01, OR: 1.06, 95%CI: 1.00-1.13, p = 0.03 respectively). PWPT in leads DII and V1 can predict the development of POAF in patients undergoing cardiac surgery.

Metoprolol versus low-dose sotalol for prevention of high-risk post coronary artery bypass grafting atrial fibrillation

Background: The optimal therapeutic strategy for high-risk postoperative atrial fibrillation (POAF) remains less well defined. Our objectives were to investigate the efficacy of prophylactic metoprolol versus low-dose sotalol regimens to prevent high-risk atrial fibrillation (AF) following coronary artery bypass surgery (CABG).&#x0D; Methods: We assigned 113 consecutive patients referred for CABG to either metoprolol or low-dose sotalol regimen. The primary end-point was the frequency of POAF during the 6-week follow-up.&#x0D; Results: Out of 113 patients enrolled, 52.2% % received metoprolol (n= 59) while 44.8% received sotalol (n= 54). The frequency of POAF at follow-up was significantly higher among the metoprolol group (59.3 % versus 50 %; P=0.017). The predictors of POAF were: age &gt; 60 years (OR: 1.86 (1.01-4.41); P= 0.03), EF (OR: 2 (1.05-3.83); P= 0.02), and sotalol was protective against POAF (OR= 0.49%; (95% CI=0.25 -0.97); P=0.02). The length of hospital stay was significantly higher in the metoprolol group (7.5±1.3 % versus 6.1±1.2 days; P&lt;0.001).&#x0D; Conclusion: Prophylactic low-dose sotalol could be superior to metoprolol for the prophylaxis of POAF in high-risk patients. However, Larger prospective multicenter randomized trials are needed to confirm our findings.

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 post-operative 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 post-operative 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, 43kg/m2 for BMI and 40mm 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 >40mm, BMI >43kg/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.

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

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

Internal Validation of a Risk Score for Prediction of Postoperative Atrial Fibrillation after Cardiac Surgery

Abstract Background: Postoperative atrial fibrillation (POAF) after cardiac surgery has great clinical and economic implications. Many attempts have been made to identify risk factors aiming at a better evaluation of prophylactic treatment strategies. Objective: To perform an internal validation of a risk score for POAF. Methods: A prospective cohort of 1,054 patients who underwent myocardial revascularization and/or valve surgery was included. The risk score model was developed in 448 patients, and its performance was tested in the remaining 606 patients. Variables with a significance level of 5% in the cohort were included and subjected to a multiple logistic regression model with backward selection. Performance statistics was performed using the c-statistic, the chi-square and the Hosmer-Lemeshow (HL) goodness-of-fit, Pearson's correlation coefficient. Results: Four variables were considered predictors of outcome: age (≥ 70 years), mitral valve disease, the non-use or discontinuation of beta-blockers and a positive water balance (> 1,500 mL). The ROC curve was 0.76 (95% confidence interval [CI]: 0.72-0.79). The risk model showed a good ability according to the performance statistics - HL test x(2) = 0.93; p = 0.983 and r = 0.99 (Pearson's coefficient). There was an increase in the frequency of POAF with the increase of the score: very low risk = 0.0%; low risk = 3.9%; intermediate risk = 10.9%; and high risk = 60.0%; p < 0.0001. Conclusion: The predictive variables of POAF allowed us to construct a simplified risk score. This scoring system showed good accuracy and can be used in routine clinical practice.

Postoperative Atrial Fibrillation Among Patients Undergoing Isolated Coronary Artery Bypass Grafting.

IntroductionPostoperative 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.MethodsThis 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).ResultsA 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).ConclusionThe 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.

Efficacy of posterior pericardiotomy in prevention of atrial fibrillation and pericardial effusion after aortic valve replacement: a randomized controlled trial

Aim. Postoperative atrial fibrillation is one of the most frequent complications in cardiac surgery. The aim of this trial was to evaluate the effectiveness of posterior pericardiotomy in the prevention of postoperative atrial fibrillation and pericardial effusion in patients undergoing isolated primary aortic valve replacement.Methods. The trial was approved by the local ethics committee. It included adult patients under 70 y.o. who had signed the informed consent for participation in the study and who were planned to undergo isolated primary aortic valve replacement. Exclusion criteria were a history of atrial fibrillation, hyperthyroidism, amiodarone intake, severe chronic obstructive pulmonary disease, left ventricle ejection fraction less than 30%, the size of the left atrium exceeding 50 mm, active infective endocarditis, the presence of adhesions in the pericardium and/or left pleural cavity and mini-sternotomy. From October 2013 to April 2015 607 patients in our clinic underwent different aortic valve procedures. 507 patients were excluded from the study because of the inclusion and exclusion criteria. The remaining 100 patients were randomized into two groups: 49 patients underwent posterior pericardiotomy and 51 patients made up the control group. In both groups the frequency of postoperative atrial fibrillation, pericardial effusion greater than 5 mm, surgery-discharge time, as well as posterior-pericardiotomy-related complications were studied. Trial number: ISRCTN11129539.Results. There were no deaths, stroke or cardiac tamponade during the postoperative stay. Neither were there any complications associated with the performance of posterior pericardiotomy. The incidence of atrial fibrillation, pericardial effusion and average duration of the postoperative stay were similar in both groups: 16% in posterior pericardiotomy group vs 14% in the control group (p=0.71), 10% in posterior pericardiotomy group vs 12% in the control group (p=0.80) and 12.4±4.3 days in posterior pericardiotomy group vs 11.9±4.1 days in the control group (p=0.27), respectively.Conclusion. The trial did not confirm the effectiveness of posterior pericardiotomy in preventing postoperative atrial fibrillation and pericardial effusion during the in-hospital period after isolated primary aortic valve replacement in low risk patients. However, further investigations are needed.Received 1 December 2016. Accepted 14 February 2017.Funding: The trial was carried out within the dissertation research and according to the research calendar of Kuban State Medical University. There was no additional funding except for the resources allocated for postgraduate scholarships.Conflict of interest: The authors declare no conflict of interest.Author contributionsConception and study design: V.I. Kaleda, K.O. Barbuhatti.Data collection and analysis: V.I. Kaleda, S.Yu. Boldyrev, S.A. Belash, I.I. Yakuba, S.S. Babeshko, I.A. Belan. Drafting the article: V.I. Kaleda.Critical revision of the article: V.I. Kaleda.Final approval of the version to be published: V.I. Kaleda, S.Yu. Boldyrev, S.A. Belash, I.I. Yakuba, S.S. Babeshko, I.A. Belan, K.O. Barbuhatti.Acknowledgements: The authors would like to express their gratitude to Cand. Sci. (Engineering) V.P. Leonov (“Biometrika”) for assistance in statistical data processing.

Impact of postoperative thoracic epidural analgesia on the frequency of postoperative atrial fibrillation in lung cancer surgery

P. A. Gertsen Scientific Research Oncological Institute, Dept of Anaesthesiology & Intensive Care, Moscow, Russian Federation

Ascorbic acid versus magnesium for the prevention of atrial fibrillation after coronary artery bypass grafting surgery

Objective The aim of the study was to evaluate the prophylactic use of ascorbic acid or magnesium on frequency of postoperative atrial fibrillation (POAF) in patients undergoing coronary artery bypass grafting surgery with cardiopulmonary bypass. Patients and methods The study included 60 patients divided into three equal groups (n = 20): the control group (group C) received saline infusion, the magnesium group (group M) received 2 g magnesium sulfate after induction of anesthesia, 1 g after 12 h followed by 1 g/8 h daily until the fifth postoperative (PO) day and the ascorbic acid group (group A) received 2 g ascorbic acid after induction of anesthesia, then 1 g after 12 h followed by 1 g/8 h daily until the fifth PO day. Operative and PO data were recorded. Primary endpoint was detection of an episode of atrial fibrillation (AF) lasting more than 10 min or the requirement for urgent intervention due to AF. Results Sixteen (26.7%) patients developed POAF, eight (40%) patients in group C, five (25%) in group M, and three (15%) in group A, with significantly higher frequency in group C compared with group M (P1 = 0.041) and group A (P2 = 0.001) but with nonsignificantly (P3 = 0.083) higher frequency in group M compared with group A. Four patients developed POAF on the first and 12 patients on the second PO day with nonsignificant intergroup difference. The mean duration of ICU stay was significantly longer in group C compared with groups M (P1 = 0.016) and A (P2 = 0.006), with nonsignificantly (P3 = 0.480) longer duration in group M compared with group A. The mean duration of PO hospital stay was significantly longer in group C compared with groups M (P1 = 0.008) and A (P2 = 0.004), with nonsignificantly (P3 = 0.415) longer duration in group M compared with group A. Conclusion Prophylactic use of ascorbic acid or magnesium significantly reduced the frequency of POAF after coronary artery bypass grafting surgery and significantly reduced ICU and hospital stay.

Correlation Between Total Atrial Conduction Time Estimated via Tissue Doppler Imaging (PA‐TDI Interval), Structural Atrial Remodeling and New‐Onset of Atrial Fibrillation After Cardiac Surgery

Recent studies identified total atrial conduction time (TACT) as an independent and powerful predictor of new-onset atrial fibrillation (AF). The purpose of this study was to assess the association between the degree of atrial fibrosis, TACT, and frequency of postoperative atrial fibrillation (POAF) among patients undergoing cardiac surgery. Sixty patients in sinus rhythm (mean ± SD age 66 ± 10 years; 22% women) and without a history of AF undergoing cardiac surgery were prospectively enrolled. TACT was measured preoperatively in the left atrium by tissue-Doppler Imaging (PA-TDI interval). Holter-ECG/telemetry was used to screen for POAF throughout 10 days after cardiac surgery. Right atrial appendages (RAA) were obtained in 33 patients during surgery; atrial fibrosis was assessed by visual quantification (% area of positive van Gieson elastic staining). POAF occurred in 23 patients (38%). Fibrosis extent of RAA was higher in patients with POAF as compared to those without (27.5 ± 1.93 vs 15.8 ± 0.81% area; mean ± SEM; P < 0.001). PA-TDI interval was longer in patients with POAF versus patients who maintained in sinus rhythm (152.1 ± 3.0 vs 120.8 ± 1.8 milliseconds; P < 0.001) and correlated with the degree of atrial fibrosis (r = 0.73; P < 0.01). At the cut-off value of 133 milliseconds, TACT sensitivity and specificity related to POAF were 100% and 86%, respectively. PA-TDI interval is useful to identify patients at risk for POAF undergoing cardiac surgery and correlates with the degree of atrial fibrosis.

The Impact of Sub-valvular Apparatus Preservation on Prosthetic Valve Dysfunction During Mitral Valve Replacement.

Background:Sub-valvular apparatus preservation (SAP) during mitral valve replacement (MVR) is not a new concept. Some surgeons prefer to excise the apparatus.Objectives:The aim of this study was to reduce the risk of prosthetic valve dysfunction.Materials and Methods:This retrospective study included 151 patients with the mean age of 46 years who underwent MVR (Female/male = 93/58). In the group I consisting of 39 patients, MVR with chordae preservation was performed (Bi-leaflet preservation = 20; posterior leaflet preservation = 19). In the group II consisting of 112 patients, sub-valvular apparatus was resected completely during MVR. Preoperative patients’ characteristics, including age, sex, functional status, left ventricular ejection fraction, and end-diastolic or end-systolic dimensions were statistically similar in both groups. Mean follow-up period was 60.3 ± 26 months.Results:The improvement of functional status was seen in almost all survivors but was more obvious in the group I. In early follow-up, 56.4% of group I cases and 44.1% of group II patients were classified as New York Heart Association class I. These rates were 84.2% and 71.2% in mid-term follow-up, respectively (P < 0.001). Mortality rate was significantly lower in the group I (2.6%) compared to the group II (8.9%) (P = 0.03). There was a trend for higher frequency of postoperative atrial fibrillation in the group II compared to that in the group I (52.7% vs. 38.5%, P = 0.12).The incidence of prosthetic valve dysfunction (PVD) was 5.1% in the group I and 4.5% in the group II, but this difference was not statistically significant (P = 0.56).Conclusions:Preservation of mitral annulus and papillary muscle continuity may enhance post- MVR cardiac performance with low mortality and morbidity rates. The risk of PVD was not significantly higher than conventional MVR in our series.

Warm-blood cardioplegia with low or high magnesium for coronary bypass surgery: a randomised controlled trial

Objective: Magnesium (Mg2+) is cardioprotective and has been routinely used to supplement cardioplegic solutions during coronary artery bypass graft (CABG) surgery. However, there is no consensus about the Mg2+ concentration that should be used. The aim of this study was to compare the effects of intermittent antegrade warm-blood cardioplegia supplemented with either low- or high-concentration Mg2+. Methods: This study was a randomised controlled trial carried out in two cardiac surgery centres, Bristol, UK and Cuneo, Italy. Patients undergoing isolated CABG with cardiopulmonary bypass were eligible. Patients were randomised to receive warm-blood cardioplegia supplemented with 5 or 16 mmol l−1 Mg2+. The primary outcome was postoperative atrial fibrillation. Secondary outcomes were serum biochemical markers (troponin I, Mg2+, potassium, lactate and creatinine) and time-to-plegia arrest. Intra-operative and postoperative clinical outcomes were also recorded. Results: Data from two centres for 691 patients (342 low and 349 high Mg2+) were analysed. Baseline characteristics were similar for both groups. There was no significant difference in the frequency of postoperative atrial fibrillation in the high (32.8%) and low (32.0%) groups (risk ratio 1.03, 95% confidence interval, CI, 0.82–1.28). However, compared with the low group, troponin I release was 28% less (95% CI 55–94%, p = 0.02) in the high-Mg2+ group. The 30-day mortality was 0.72% (n = 5); all deaths occurred in the high-Mg2+ group but there was no significant difference between the groups (p = 0.06). Frequencies of other major complications were similar in the two groups. Conclusions: Warm-blood cardioplegia supplemented with 16 mmol l−1 Mg2+, compared with 5 mmol l−1 Mg2+, does not reduce the frequency of postoperative atrial fibrillation in patients undergoing CABG but may reduce cardiac injury. (This trial was registered as ISRCTN95530505.)

Effect of Race on the Frequency of Postoperative Atrial Fibrillation Following Coronary Artery Bypass Grafting

Atrial fibrillation (AF) commonly complicates the postoperative course after coronary artery bypass grafting (CABG). Among the general population, African Americans have been shown to have a lower prevalence of AF than European Americans. Although many factors have been identified to predict risk for postoperative AF, race has not been examined. All patients aged ≥18 years who underwent CABG at Henry Ford Hospital during a 5-year period from January 1, 2004, to December 31, 2008, were included. Patients were excluded for any previous diagnosis of AF or if they had concomitant valve surgery at the time of CABG. The incidence of AF was determined by International Classification of Diseases, Ninth Revision, coding from postoperative hospitalization records. Overall, 1,001 patients were eligible for analysis. Of these, 731 (73%) were European American and 270 (27%) were African American. The African American group had a higher prevalence of hypertension (75.6% vs 58.8%, p <0.001) and heart failure (22.6% vs 15.7%, p = 0.01) and a trend toward a higher prevalence of diabetes mellitus (38.1% vs 33.4%, p = 0.159). Postoperative AF was diagnosed in 214 European Americans (29.3%) and 50 African Americans (18.5%) (p = 0.001). In multivariate analysis adjusting for age strata, gender, hypertension, diabetes, and heart failure, African Americans had less postoperative AF than European Americans, with an adjusted odds ratio of 0.539 (95% confidence interval 0.374 to 0.777, p = 0.001). In conclusion, African Americans have a significantly reduced incidence of AF compared to European Americans after CABG.

Effect of aprotinin on the frequency of postoperative atrial fibrillation or flutter

The relationship between adding aprotinin to standard care and the frequency of postoperative atrial fibrillation or flutter (POAF) in patients undergoing cardiothoracic surgery (CTS) with cardiopulmonary bypass (CPB) was studied. This was a retrospective cohort evaluation. All patients at a hospital who underwent CTS with CPB between October 1999 and October 2003 and who received aprotinin during surgery were included in the treatment group. Control patients were those who did not receive aprotinin; they were matched with treatment group patients for age, valvular surgery, history of atrial fibrillation or flutter, renal dysfunction, peripheral artery disease, smoking, angina, diabetes mellitus, congestive heart failure, previous CTS, sex, beta-blocker intolerance, and use of preoperative digoxin. The primary endpoint was POAF; secondary endpoints were perioperative transfusion use, length of stay (LOS), stroke, myocardial infarction, renal failure, graft occlusion, and death. A total of 438 patients (219 per group) were evaluated. The patients' mean age was 68 years, 67% were men, and 74% had had valvular surgery. Patients who received aprotinin (mean +/- S.D. dose, 2.75 million +/- 1.24 million kallikrein-inhibiting units) did not have a significantly lower frequency of POAF than control patients (28% versus 27%, respectively [p = 0.92]), nor was there a significant difference in secondary endpoints. Aprotinin therapy was not associated with a significant reduction in POAF in patients undergoing CTS with CPB. Perioperative transfusion use, LOS, stroke, myocardial infarction, renal failure, graft occlusion, and mortality also did not differ significantly between aprotinin and control groups.

Magnesium sulfate for prevention of postoperative atrial fibrillation in patients undergoing coronary artery bypass grafting

The effects of i.v. magnesium sulfate on the frequency of postoperative atrial fibrillation (AF) in patients undergoing coronary artery bypass grafting (CABG) and on the frequency of AF at hospital discharge were studied. The effect of postoperative AF on hospital length of stay (LOS) was also assessed. A retrospective chart review was performed for all patients who underwent CABG surgery by a single surgeon during 2000-2001 at a community medical center. Patients were eligible for inclusion if they had first-time CABG surgery. Patients who underwent CABG surgery in 2000 did not receive magnesium sulfate and served as controls for the study. Patients were included in the magnesium group if they received 2 g of i.v. magnesium sulfate intraoperatively and 2 g every 12 hours postoperatively for at least two consecutive days. A total of 262 patients underwent CABG during the study period, and 28 were excluded from the study. Of the remaining 234 patients, 99 were in the magnesium group, and 135 were in the control group. No significant differences were found between the study groups in recorded demographic characteristics. Postoperative AF occurred significantly less frequently in the magnesium group (p = 0.038). There was no significant difference between treatment groups in the number of patients discharged in AF (p = 0.307). Among all patients, those with AF were significantly more likely to have a prolonged LOS (p = 0.036). CABG patients who received intraoperative and postoperative i.v. magnesium sulfate had a significantly lower rate of AF compared with patients who did not receive the drug. The number of patients discharged with AF was not affected by magnesium administration. AF was associated with a higher likelihood of prolonged postoperative hospitalization.