Predictors of Postoperative Atrial Fibrillation in Patients With Coronary Artery Disease Undergoing Cardiopulmonary Bypass: A Possible Role for Myocardial Ischemia and Atrial Inflammation

Comprehensive Analysis of Factors Associated with New Episode of Postoperative Atrial Fibrillation after Coronary Artery Bypass Graft Surgery

The aim of the study was to perform a comprehensive fundamental analysis of the factors of inflammation, oxidative stress, fibrosis, myocardial dysfunction, ischemia and omega-3 index associated with postoperative atrial fibrillation (POAF) after coronary artery bypass graft (CABG) surgery in patients with coronary artery disease. The study involved 158 patients who were admitted to the hospital to undergo CABG surgery. Patients were divided into two groups: group 1 comprised 111 patients without POAF (82% males, median age-62.0 (56.0; 66.0) years), and group 2 comprised 47 patients with POAF (84.4% males, median age-65.0 (61.0; 70.0) years). POAF occurred 5.2 (2.0; 7.0) days after CABG. In all the patients, we evaluated laboratory tests before and 3-4 days after CABG. All the patients also underwent echocardiography. According to results of multifactorial regression analysis, the odds ratio of POAF development for left atrial diameter >41 mm was 4.3 (95% confidence interval (CI) 2.0-9.7, p < 0.001), interleukin (IL)-6 postoperative levels >22.07 pg/mL-3.0 (95% CI 1.4-8.2, p = 0.006), IL-8 postoperative levels >9.67 pg/mL-2.3 (95% CI 1.2-7.3, p = 0.006), superoxide dismutase postoperative levels in plasma >1100.5 U/g-3.2 (95% CI 1.4-9.2, p = 0.03), glutathione postoperative levels ≤0.194 micromole/g of hemoglobin-1.9 (95% CI 1.2-6.3, p < 0.001), glutathione peroxidase postoperative levels ≤17.36 millimole/g of hemoglobin-2.2 (95% CI 1.1-8.2, p < 0.001), glutathione reductase postoperative levels ≤2.99 millimole/g of hemoglobin-2.3 (95% CI, 1.1-5.7, p < 0.001), malondialdehyde postoperative levels >1.25 micromole/g of hemoglobin-2.0 (95% CI, 1.2-7.9, p < 0.001), NO postoperative levels in plasma >36.4 micromole/L-1.5 (95% CI, 1.1-5.9, p < 0.001) and omega-3 index ≤1.59%-2.6 (95% CI 1.5-9.1, p < 0.001). Our study showed that increased left atrial diameter, high postoperative levels of inflammatory factors, oxidative stress, fibrosis indicators and omega-3 index were associated with POAF in patients who underwent CABG.

High-Sensitivity Cardiac Troponin I and T Kinetics Differ following Coronary Bypass Surgery: A Systematic Review and Meta-Analysis

Background

Cardiac troponin I and T are both used for diagnosing myocardial infarction (MI) after coronary artery bypass grafting (CABG), also known as type 5 MI (MI-5). Different MI-5 definitions have been formulated, using multiples of the 99th percentile upper reference limit (10×, 35×, or 70× URL), with or without supporting evidence. These definitions are arbitrarily chosen based on conventional assays and do not differentiate between troponin I and T. We therefore investigated the kinetics of high-sensitivity cardiac troponin I (hs-cTnI) and T (hs-cTnT) following CABG.

Methods

A systematic search was applied to MEDLINE and EMBASE databases including the search terms “coronary artery bypass grafting” AND “high-sensitivity cardiac troponin.” Studies reporting hs-cTnI or hs-cTnT on at least 2 different time points were included. Troponin concentrations were extracted and normalized to the assay-specific URL.

Results

For hs-cTnI and hs-cTnT, 17 (n = 1661 patients) and 15 studies (n = 2646 patients) were included, respectively. Preoperative hs-cTnI was 6.1× URL (95% confidence intervals: 4.9–7.2) and hs-cTnT 1.2× URL (0.9–1.4). Mean peak was reached 6–8 h postoperatively (126× URL, 99–153 and 45× URL, 29–61, respectively). Subanalysis of hs-cTnI illustrated assay-specific peak heights and kinetics, while subanalysis of surgical strategies revealed 3-fold higher hs-cTnI than hs-cTnT for on-pump CABG and 5-fold for off-pump CABG.

Conclusion

Postoperative hs-cTnI and hs-cTnT following CABG surpass most current diagnostic cutoff values. hs-cTnI was almost 3-fold higher than hs-cTnT, and appeared to be highly dependent on the assay used and surgical strategy. There is a need for assay-specific hs-cTnI and hs-cTnT cutoff values for accurate, timely identification of MI-5.

Perioperative Cardiac Troponin T and Risk of Postoperative Atrial Fibrillation in Coronary Artery Bypass Graft Surgery

BACKGROUND

Postoperative atrial fibrillation (AF) is a common complication after cardiac surgery. We investigated whether perioperative cardiac troponin T (cTnT) is associated with the risk of AF after coronary artery bypass grafting (CABG).

METHODS

Two thousand four hundred twenty-one patients with isolated CABG were studied. High sensitivity cTnT (hs-cTnT) was assessed before and then at 80 hour and 24 hour after the operation. Logistic regression models were applied to investigate the association of perioperative hs-cTnT with postoperative AF. The ROC curve analysis was applied to determine the optimal cutoff values.

RESULTS

Postoperative AF was occurred in 356 (14.7%) patients. Age (adjusted odds ratio [ORs] 1.087-1.090), male gender (OR 1.390), left atrium size (ORs 1.055-1.111), on-pump coronary bypass (OR 1.561), and application of intra-aortic balloon pump (ORs 2.890-2.966) were independently associated with AF. Preoperative hs-cTnT was associated with AF in patients with off-pump coronary bypass (ORs 1.997-2.375). However, the area under the curve for preoperative hs-cTnT was 0.625 in this group. On-pump coronary bypass had major influence on postoperative hs-cTnT levels regardless of the occurrence of AF.

CONCLUSIONS

Preoperative hs-cTnT level is associated with the risk of AF after isolated CABG in patients undergoing off-pump coronary bypass, but the accuracy of this biomarker is yet inadequate. Postoperative levels of hs-cTnT have no predictive value considering large influence by the surgical technique and the cardiac surgery itself. Therefore, perioperative hs-cTnT is not a clinically useful biomarker for predicting AF following CABG.

Meta-Analysis Evaluating High-Sensitivity Cardiac Troponin T Kinetics after Coronary Artery Bypass Grafting in Relation to the Current Definitions of Myocardial Infarction

Various definitions of myocardial infarction type 5 after coronary artery bypass grafting (CABG) have been proposed (myocardial infarction [MI-5], also known as peri-procedural MI), using different biomarkers and different and arbitrary cut-off values. This meta-analysis aims to determine the expected release of high-sensitivity cardiac troponin T (hs-cTnT) after CABG in general and after uncomplicated surgery and off-pump CABG in particular. A systematic search was applied to 3 databases. Studies on CABG as a single intervention and reporting on postoperative hs-cTnT concentrations on at least 2 different time points were included. All data on hs-cTnT concentrations were extracted, and mean concentrations at various points in time were stratified. Eventually, 15 studies were included, encompassing 2,646 patients. Preoperative hs-cTnT was 17 ng/L (95% confidence interval [CI] 13 to 20 ng/L). Hs-cTnT peaked at 6 to 8 hours postoperatively (628 ng/L, 95% CI 400 to 856 ng/L; 45x upper reference limit [URL]) and was still increased after 48 hours. In addition, peak hs-cTnT concentration was 614 ng/L (95% CI 282 to 947 ng/L) in patients with a definite uncomplicated postoperative course (i.e., without MI). For patients after off-pump CABG compared to on-pump CABG, the mean peak hs-cTnT concentration was 186 ng/L (95% CI 172 to 200 ng/L, 13 × URL) versus 629 ng/L (95% CI 529 to 726 ng/L, 45 × URL), respectively. In conclusion, postoperative hs-cTnT concentrations surpass most of the currently defined cut-off values for MI-5, even in perceived uncomplicated surgery, suggesting thorough reassessment. Hs-cTnT release differences following on-pump CABG versus off-pump CABG were observed, implying the need for different cut-off values for different surgical strategies.

Omega-3 Polyunsaturated Fatty Acids: the Role in Prevention of Atrial Fibrillation in Patients with Coronary Artery Disease after Coronary Artery Bypass Graft Surgery

Aim. To estimate the role of omega-3 polyunsaturated fatty acids (PUFAs) administration in atrial fibrillation (AF) prevention after planned coronary artery bypass graft (CABG) surgery.

Material and Methods. Studied were 306 patients divided into two groups: patients of group I didn’t receive PUFAs (158 patients, 82.7% males) and patients of group II received PUFAs (148 patients, 89.3% males). PUFAs were prescribed in daily dose 2000 mg 5 days before surgery and in daily dose 1000 mg in postoperative period during 21 days.

Results. Postoperative AF (POAF) occurred in 29.7% patients in group I and in 16.9% patients in group II (р=0.009). We found that after CABG in patients of the I group median IL-6 level was 39.3% higher (p=0.001), interleukin-10 – 20.2% higher (p=0.01), superoxide dismutase – 78.9% higher (р<0.001), malondialdehyde – 33.8% higher (p=0.03), docosahexaenoic acid – 31.8% lower (p=0.01) and omega-3 index – 43.4%    lower (p=0.04) than in patients of the II group.

According to multivariate regression analysis we found significant association between the factors of inflammation, oxidative stress and the risk POAF development.

Conclusions. In patients who took PUFAs, we found less activation of inflammation, oxidative stress, the increasing of docosahexaenoic acid and omega-3 index accompanied by the decreasing of POAF development rates up to 12.8%.

Obstructive sleep apnea-induced multi-organ dysfunction after elective coronary artery bypass surgery in coronary heart disease patients

Background

The aim of this study was to explore the underlying impact of obstructive sleep apnea (OSA) on postoperative parameters of multi-organ function among coronary heart disease (CHD) patients following elective coronary artery bypass grafting (CABG).

Methods

Electronic literature databases were searched manually and automatically for relevant English articles. All of the included articles focused on a comparison of the incidence of postoperative parameters of multi-organ function in CHD patients undergoing elective CABG with and without OSA. Studies were excluded if they met any one of the following criteria: (I) duplicate publication; (II) ongoing or unpublished studies; (III) only published as abstracts or conference proceedings; and (IV) less than 30 patients in the patient cohort.

Results

A total of 13 articles met our inclusion criteria. The current study demonstrated OSA significantly increased the incidence of major adverse cardiac and cerebrovascular events (MACCEs) in CHD patients undergoing elective CABG compared with the controls [odds risk (OR), 1.97; 95% CI, 1.50 to 2.59, P<0.0001]. In addition, OSA was associated with an increased risk of new revascularization in CHD patients undergoing elective CABG (OR, 9.47; 95% CI, 2.69 to 33.33, P<0.0001). Moreover, reintubation and tracheostomy in the OSA group was increased 243% (OR, 3.43; 95% CI, 1.35 to 8.71; P=0.009) and 372% (OR, 4.72; 95% CI, 1.23 to 18.13; P=0.024), respectively, compared with the control group. Besides, we also confirmed OSA significantly increased the acute kidney injury (AKI) incidence by 124% (OR, 2.24; 95% CI, 1.07 to 4.72; P<0.0001).

Conclusions

OSA may contribute to postoperative multi-organ dysfunction among CHD patients undergoing elective CABG by increasing the incidence of MACCEs, especially new revascularization, as well as respiratory, and renal complications.

Predicting postoperative atrial fibrillation after myocardial revascularization without cardiopulmonary bypass: A retrospective cohort study

INTRODUCTION

Considering the threat imposed by postoperative atrial fibrillation (POAF) after coronary artery bypass grafting (CABG) and the potential benefits of off-pump CABG, the objective of this study was to describe the incidence and identify predictor factors for POAF in patients undergoing CABG without cardiopulmonary bypass (CPB).

METHODS

In this retrospective cohort study, we enrolled patients undergoing CABG without CPB between December 2008 and December 2011. The independent variables evaluated in this study were major patients' characteristics (age, sex, and ethnia), associated comorbidities (systemic arterial hypertension, diabetes mellitus, thyroid dysfunction, chronic renal failure (CRF), chronic obstructive pulmonary disease, and ischemic stroke), and the revascularization approach (the number of grafts used, the revascularized branch, and the choice of vascular graft (arterial or venous). The dependent variable was the onset of atrial fibrillation after the procedure.

RESULTS

Two hundred and eighty patients were included in the present study. The overall incidence of POAF after off-pump CABG was 5.0%. In the univariate analysis, the presence of chronic renal failure (odds ratio [OR], 3.01 [1.00-9.06], P = .049) and the use of venous-origin graft alone (OR, 9.67 [1.15-81.56], P = .037) were associated with an increased risk or POAF. These findings were confirmed after multivariate analysis, for both CRF (OR, 3.31 [1.05-10.46], P = .042) and the use of venous-origin graft alone (OR, 9.81 [1.13-85.35], P = .039).

CONCLUSION

Off-pump coronary artery bypass grafting proved a safe and effective procedure, with low postoperative atrial fibrillation occurrence, for myocardial revascularization. Chronic renal insufficiency and the use of venous-origin graft solely proved to be independent predictor factors for PAOF.

Biomarkers of Atrial Fibrillation: Which One Is a True Marker?

Atrial fibrillation (AF) is the most common sustained cardiac arrhythmias and associated with the risk of stroke and death. Continuous development of the diagnostic tool and prognostic stratification may lead to optimal management of AF. The use of biomarkers in the management of AF has been grown as an interesting topic. However, the AF biomarkers are not yet well established in the major guidelines. Among these biomarkers, a lot of data show troponin and brain natriuretic peptides are promising for the prediction of future events. The troponin elevation in AF patients may not necessarily be diagnosed as myocardial infarction or significant coronary artery stenosis, and brain natriuretic peptide elevation may not necessarily confirm heart failure. Troponin T and troponin I may predict postoperative AF. Furthermore, troponin and brain natriuretic peptide gave better prognostic performance when compared with the risk score available today.

Atrial contractility and fibrotic biomarkers are associated with atrial fibrillation after elective coronary artery bypass grafting

OBJECTIVE

New-onset postoperative atrial fibrillation is common after cardiac surgery. Less has been reported about the relationship among fibrosis, inflammation, calcium-induced left atrial and right atrial contractile forces, and postoperative atrial fibrillation. We sought to identify predictors of postoperative atrial fibrillation.

METHODS

From August 2016 to February 2018, we evaluated 229 patients who had preoperative sinus rhythm before elective primary coronary artery bypass grafting. Of 229 patients, 191 maintained sinus rhythm postoperatively, whereas 38 patients developed atrial fibrillation. Preoperative tissue inhibitor of metalloproteinase-1, pentraxin-3, matrix metallopeptidase-9, galectin-3, high-sensitivity C-reactive protein, growth differentiation factor 15, and transforming growth factor-ß were measured. Clinical and echocardiographic findings (tricuspid annular plane systolic excursion for right heart function) and calcium-induced force measurements from left atrial and right atrial-derived skinned myocardial fibers were recorded.

RESULTS

Patients with atrial fibrillation were older (P = .001), had enlarged left atrial (P = .0001) and right atrial areas (P = .0001), and had decreased tricuspid annular plane systolic excursion (P = .001). Levels of matrix metallopeptidase-9 and pentraxin-3 were decreased (P < .05), whereas growth differentiation factor 15 was increased (P = .001). We detected lower left atrial force values at calcium-induced force measurements 5.5 (P < .05), 5.4 (P < .01), and 5.3 to 4.52 (P = .0001) and right atrial force values at calcium-induced force measurements 5.0 to 4.52 (P < .05) in patients with postoperative atrial fibrillation. Multivariable analysis showed that advanced age (P = .033), decreased left atrial force value at calcium-induced force measurement of 5.5 (P = .033), enlarged left atrial (P = .013) and right atrial (P = .081) areas, and reduced tricuspid annular plane systolic excursion (P = .010) independently predicted postoperative atrial fibrillation.

CONCLUSIONS

Advanced age, decreased left atrial force value at calcium-induced force measurement of 5.5, enlarged left atrial and right atrial areas, and reduced tricuspid annular plane systolic excursion were identified as independent predictors for postoperative atrial fibrillation.

Hydrogen-rich solution attenuates myocardial injury caused by cardiopulmonary bypass in rats via the Janus-activated kinase 2/signal transducer and activator of transcription 3 signaling pathway

The incidence of complications and mortality following open-heart surgery with cardiopulmonary bypass (CPB) is associated with the severity of the myocardial injury that occurs during surgery. Hydrogen-rich solution (HRS) may prevent antioxidant stress and inhibit apoptosis and inflammation. The present study was designed to investigate the effects of HRS on CPB-induced myocardial injury, and to investigate its potential regulation of the Janus-activated kinase 2/signal transducer and activator of transcription 3 (JAK2/STAT3) pathway. The HRS treatment resulted in the significant upregulation of malonyl dialdehyde (MDA) and myeloperoxidase (MPO), whilesuperoxide dismutase (SOD) levels were significantly downregulated, compared with the Sham group (P<0.05). Additionally, HRS treatment improved myocardial injury, and decreased the expression levels of cardiac troponins, heart-type fatty acid binding protein, interleukin (IL)-1β, IL-6, tumor necrosis factor (TNF)-α, MDA and MPO, and increased SOD release in CPB rats (P<0.05). Additionally, in the CPB group without the HRS treatment, the expression levels of B-cell lymphoma (Bcl)-2, JAK2, phospho-JAK2 (p-JAK2), STAT3 and phospho-STAT3 (p-STAT3) were significantly decreased, and Bax was significantly increased, compared with the Sham group (P<0.05). By contrast, compared with the CPB group, the expression levels of B-cell lymphoma 2 (Bcl-2), JAK2, phosphorylated (p)-JAK2, STAT3 and p-STAT3 in the HRS group were significantly increased, and Bcl-2-associated X protein expression was significantly decreased (P<0.05). In JAK2 knockdown experiments using siRNA, HRS treatment following hypoxia/reoxygenation also significantly increased the viability of myocardial cells, decreased the rate of myocardial cell apoptosis, elevated the levels of SOD and suppressed the release of MDA and lactate dehydrogenase in the control siRNA and CPB groups (P<0.05). Furthermore, JAK2 siRNA attenuated these protective effects of HRS (P<0.05 vs. control siRNA, HRS and CPB groups). Additionally, the results demonstrated that the HRS treatment significantly increased the expression levels of p-JAK2, p-STAT3 and Bcl-2 in myocardial cells following hypoxia and decreased Bax expression in the control siRNA and CPB groups (P<0.05). In addition, JAK2 siRNA was determined to attenuate these effects of HRS (P<0.05 vs. control siRNA, HRS and CPB groups). Taken together, these results indicated that HRS may alleviate CPB-induced myocardial injury, inhibit myocardial cell apoptosis and protect myocardial cells through regulation of the JAK2/STAT3 signaling pathway.

Clinical Applications of Biomarkers in Atrial Fibrillation

While biomarkers have greatly impacted the diagnosis and management of myocardial infarction and heart failure, the use of biomarkers has been slow to permeate management of atrial fibrillation. Guideline recommendations on the use of biomarkers in atrial fibrillation were virtually nonexistent until the 2016 European Society of Cardiology guidelines on atrial fibrillation offered a class IIb recommendation to consider using biomarkers such as high-sensitivity troponin and natriuretic peptide to further refine stroke and bleeding risk in atrial fibrillation patients. Biomarker levels have been associated with incident atrial fibrillation, postoperative atrial fibrillation, acute atrial fibrillation, diagnosis of myocardial infarction and heart failure in atrial fibrillation, and prognosis in atrial fibrillation. This review will offer an in-depth survey of current evidence on the use of biomarkers in atrial fibrillation and propose clinical algorithms to aid the internist in using biomarkers in atrial fibrillation management.

Risk factors for delirium after cardiac surgery: a historical cohort study outlining the influence of cardiopulmonary bypass

PURPOSE

Cardiopulmonary bypass (CPB) induces a significant inflammatory response that may increase the risk for delirium. We hypothesized that exposure to CPB during coronary artery bypass grafting (CABG) surgery would correlate with an increased risk of delirium.

METHODS

We reviewed clinical data from two databases at our medical centre - the Cardiac Surgery Perioperative Outcomes Database and the Society of Thoracic Surgeons Database. Patients undergoing elective CABG surgery (on-pump and off-pump) from November 1, 2009 to September 30, 2015 were included in the study. Delirium was defined as any postoperative positive Confusion Assessment Method for the Intensive Care Unit exam during the intensive care unit stay. We performed logistic regression to isolate the association between CPB exposure and delirium adjusted for predetermined risk factors and potential confounders.

RESULTS

During the study period, 2,280 patients underwent elective CABG surgery, with 384 patients (16.9%) exposed to CPB. Delirium was diagnosed in 451 patients (19.8%). Exposure to CPB showed a significant independent association with delirium. Patients exposed to CPB for 142 min (90^th percentile of CPB duration) vs those exposed for 54 min (10^th percentile) had an adjusted relative risk (RR) of delirium of 2.18 (95% confidence interval [CI], 1.39 to 3.07; P = 0.002) vs a RR of 1.51 (95% CI, 0.92 to 2.29; P = 0.10), respectively.

CONCLUSIONS

The use and duration of cardiopulmonary bypass were associated with an increased risk of delirium in patients undergoing CABG surgery.

TRIAL REGISTRATION

www.clinicaltrials.gov , NCT02548975. Registered 4 September 2015.

High-Sensitivity Troponin as a Biomarker in Heart Rhythm Disease

Biomarkers are important prognostic tools in various cardiovascular conditions, including coronary artery disease and heart failure. Although their utility in cardiac electrophysiology (EP) is less established, biomarkers may guide EP clinical practice by identifying patients at risk for developing arrhythmias and their complications, in addition to augmenting therapeutic decisions by targeting appropriate pharmacologic and interventional therapies to patients who may benefit most. In this review, we focus on the prognostic role of high-sensitivity cardiac troponin (hs-cTn) assays-which detect subclinical cardiac myocyte damage-in cardiac arrhythmias and their sequelae. We review the current literature on hs-cTn and its impact on various arrhythmia disease states and also provide suggestions for future research in this field. In conclusion, although the utility of hs-cTn assays remains at an investigational stage in cardiac EP, studies to date have suggested value as a prognostic biomarker in atrial fibrillation and as a screening marker for patients at high risk of sudden cardiac death (both in the general population and among those with hypertrophic cardiomyopathy).

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

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

Do preoperative C-reactive protein and mean platelet volume levels predict development of postoperative atrial fibrillation in patients undergoing isolated coronary artery bypass grafting?

Introduction

Atrial fibrillation (AF) after coronary artery bypass grafting (CABG) operation is associated with increased risk of prolonged hospitalisation, health expenses and adverse clinical outcomes.

Aim

To investigate the relationship of atrial fibrillation after an isolated coronary artery bypass operation with levels of mean platelet volume and C-reactive protein.

Material and methods

Among 1240 patients who underwent operations for isolated coronary artery bypass grafting with cardiopulmonary bypass between January 2007 and May 2014, 1138 (91.8%) patients with preoperative normal sinusal rhythm were enrolled in the study. Patients were assigned to group 1 (n = 294) comprising patients who developed atrial fibrillation in the first 72 postoperative hours or group 2 (n = 844) comprising patients who remained in normal sinusal rhythm in the postoperative period.

Results

The incidence of postoperative atrial fibrillation was 25.8%. The preoperative mean platelet volume (fl) and C-reactive protein (mg/dl) values in group 1 were 9.1 ±0.5 and 1.1 ±0.9 respectively, while these values were 8.3 ±0.6 and 0.5 ±0.3 respectively in group 2, which was statistically significant (p = 0.0001). Length of stay in the hospital (p = 0.0001) was higher in group 1. The values of mean platelet volume (fl) and mean C-reactive protein (mg/dl) were 9.9 ±0.9 and 30.9 ±3.4 respectively in group 1, while the values of mean platelet volume (fl) and mean C-reactive protein (mg/dl) were 8.8 ±0.6 and 24.9 ±4.8 respectively in group 2 (p = 0.0001 for mean platelet volume, p = 0.0001 for C-reactive protein). The difference between the groups was statistically significant in terms of postoperative neurologic events (p = 0.0001) and hospital mortality (p = 0.001). Increased C-reactive protein and mean platelet volume levels were found to be independent predictors of postoperative atrial fibrillation.

Conclusions

In our study, elevated preoperative mean platelet volume and C-reactive protein levels were associated with development of postoperative atrial fibrillation.

CHADS2 and CHA2DS2-VASc scoring systems for predicting atrial fibrillation following cardiac valve surgery

Objective

Clinical use of CHADS₂ and CHA₂DS₂-VASc scoring systems for predicting AF following cardiac surgery have been reported in previous studies and demonstrated well-validated predictive value. We sought to investigate whether the two scoring systems are effective for predicting new-onset of AF following cardiac valve surgery and to demonstrate its potential utility of clinical assessment.

Methods

Medical records of all patients underwent cardiac valve surgeries during the period of January 2003 and December 2013 without preoperative AF at the cardiac center of our university were reviewed. The main outcome end point of our study was the early new-onset of AF following cardiac valve surgery.

Results

There were overall 518 patients involved in this study, with 234 (45.17%) developed POAF following valve surgery. Patients with POAF had older age (P=0.23) and higher BMI (P=0.013) than those without POAF. History of heart failure (P=0.025), hypertension (P=0.021), previous stroke or TIA (P=0.032), coronary artery disease (P=0.001), carotid artery disease (P=0.024) and preoperative medication of statins (P=0.021) were significantly more recorded in POAF group. Patients with POAF also had higher LAD (P=0.013) and E/e’ ratio (P<0.001). The CHADS₂ and CHA₂DS₂-VASc scores were significantly higher in patients with POAF (P=0.002; P<0.001), and under univariate and multivariate regression analysis the CHADS₂ and CHA₂DS₂-VASc scores were significant predictors of POAF (P=0.001; P<0.001). Based on stratification of CHADS₂ and CHA₂DS₂-VASc scores, the Kaplan-Meier analysis obtained a higher POAF rate on patients with higher stratification of CHADS₂ and CHA₂DS₂-VASc scores (P<0.001; P<0.001).

Conclusion

In conclusion, CHADS₂ and CHA₂DS₂-VASc scores were directly associated with the incidence of POAF following valve surgery and a higher score was strongly predictive of POAF.

Troponin-I is a predictor of a delayed diagnosis of atrial fibrillation in acute ischemic stroke and transient ischemic attack

BACKGROUND

Prolonged cardiac monitoring detects higher rates of atrial fibrillation (AF) in ischemic stroke and transient ischemic attack (TIA) but is costly and has practical implications. The use of admission troponin-I (TnI) level to identify patients at high risk of delayed AF detection was investigated.

METHODS

Consecutive ischemic stroke and TIA cases presenting to our institute over a 13-month period were identified from the Irish Stroke and TIA Register. Electronic databases and case notes were examined. "Delayed" AF was diagnosed after a sinus rhythm admission electrocardiogram and no documented history. Group comparisons were made by AF status. The association between TnI and AF was investigated using a multivariate regression model.

RESULTS

A total of 185 cases (130 ischemic stroke) were analyzed. Mean age (standard deviation) was 73.3 (13.9) years, 47% female. Sixty-two cases (33.5%) had AF. The first documented presentation of AF was found in 21 cases, on admission electrocardiogram (n = 11) or inpatient telemetry (delayed, n = 10). TnI was higher in those with delayed AF than in those without AF (W = 194; P = .036). A higher proportion of those with an elevated TnI (30%) than those with a normal TnI (6.1%) had delayed diagnosis of AF (χ(2) = 6.41, P = .011). Having an abnormal TnI was a significant independent predictor of delayed AF detection (odds ratio, 5.8; P = .037).

CONCLUSIONS

TnI elevation is associated with a higher likelihood of subsequent AF diagnosis. Identification of these higher risk stroke and TIA cases for more intensive cardiac monitoring may improve stroke secondary prevention practices.

Role of ACE I/D gene polymorphisms on the effect of ramipril in inflammatory response and myocardial injury in patients undergoing coronary artery bypass grafts

BACKGROUND

Angiotensin-converting enzyme (ACE) inhibitors block angiotensin II formation and release bradykinin, which is effective in the regulation of oxidoinflammatory injury. Some reports denote alterations in the effectiveness of ACE inhibitors in association with ACE insertion/deletion (I/D) gene polymorphisms. This study investigates the effects of ramipril on the oxidoinflammatory cytokines (IL-6, IL-8, TNF-alpha) and TnT (myocardial injury marker) and their alteration in association with ACE I/D gene polymorphisms.

METHODS

The study group (n = 51) patients received ramipril before coronary artery bypass grafting (CABG), while patients not receiving ramipril (n = 51) constituted the controls. TNFα, IL-6, and IL-8 were evaluated using ELISA and TnT by electrochemiluminescence methods before the induction of anesthesia (t1), at the 20th minute following cross-clamping (t2), at the end of the operation (t3), and at the 24th hour from the commencement of anesthesia (t4). Genotyping was performed by PCR.

RESULTS

Differences between the groups were significant at t4 for the TNFα and at t3 for IL-6 (p < 0.05). The TnT levels increased from t2 onward in the control group and were highest in t3. Changes in t3 and t4 values in both groups according to their t1 values were significant (p < 0.05). However, differences between the groups were insignificant (p > 0.05). The IL-6, IL-8, TNFα, and TnT serum levels had no correlation with the ACE I/D gene polymorphism.

CONCLUSION

Low cytokine and TnT levels in the study group, especially after cross-clamping, may indicate the protective effect of ramipril from oxidoinflammatory injury. This effect did not appear to be associated with the ACE I/D gene polymorphism.