Clinical and Echocardiographic Predictors of Atrial Fibrillation after Coronary Artery Bypass Grafting

Echocardiographic Predictors of Postoperative Atrial Fibrillation After Cardiac Surgery: Assessing Atrial Mechanics for Risk Stratification

Postoperative atrial fibrillation (POAF) is a common complication after cardiac surgery, increasing morbidity and healthcare costs. This study aimed to identify echocardiographic predictors of POAF to improve risk stratification. A total of 131 patients undergoing cardiac surgery were analyzed and divided into two groups based on POAF occurrence. Echocardiographic analysis showed that patients with POAF had larger left and right atrial dimensions and impaired atrial function. Prolonged total atrial conduction time (TACT), reduced atrial emptying volumes, and contractile function were more common in the POAF group. Univariable analysis identified LAEF (χ2 = 71.8, p < 0.001), LAKE (χ2 = 70.1, p < 0.001), RATEF (χ2 = 65.7, p < 0.001), and RAAEF (χ2 = 66.8, p < 0.001) as significant predictors of POAF, each with an area under the curve (AUC) greater than 0.89. In multivariable analysis, LAKE (OR = 0.27, p < 0.001), hypertension (OR = 11.87, p = 0.035), left ventricular ejection fraction (OR = 1.08, p = 0.020), and peripheral vascular disease (OR = 40.28, p = 0.002) were independent predictors. The final model showed a significant discriminatory ability (AUC = 0.94). LAKE and clinical factors remained independent predictors after adjustment.

Left atrial strain and risk of atrial fibrillation after coronary artery bypass-grafting

AIM

Postoperative Atrial Fibrillation (POAF) is a common complication following Coronary Artery Bypass Grafting (CABG), associated with increased morbidity and mortality. Aim of the study is to analyze whether the measurement of preoperative Left Atrial (LA) strain can offer advantages over conventional clinical and echocardiographic parameters to identify patients at risk of developing POAF.

METHODS AND RESULTS

We conducted a prospective study involving 100 patients undergoing isolated CABG from April 2023 to April 2024. Key parameters measured included LA strain measurements, Left Atrial Emptying Fraction (LA-EF), Left Ventricular Ejection Fraction, Left Atrial Volume index (LAVi). POAF occurred in 27 patients (27 %) with a mean latency of 3.2 ± 2.1 days. Higher preoperative serum creatinine levels were significantly associated with POAF. LA strain parameters (LA Reservoir Strain, LA Contraction Strain) and LA-EF were all significantly lower in the POAF group. Multivariate logistic regression identified LA Contraction Strain (OR: 0.73, p = 0.04), LA Reservoir Strain (OR: 0.27, p = 0.02) and preoperative serum creatinine (OR: 0.55, p = 0.01) as significant predictors of POAF. ROC curve analysis indicated that LA Reservoir Strain ≤24.5 %, LA Contraction Strain ≤9.5 %, LA-EF ≤ 43.4 % have a good accuracy in detection of POAF. Significant correlations were found between LAVi and LA Reservoir Strain, LAVi and LA-EF, and LA Reservoir Strain and LA-EF.

CONCLUSIONS

Preoperative LA analysis are significant predictors of POAF. These findings suggest that echocardiographic strain measurements offer an added value in preoperative risk assessment for POAF in CABG patients.

Left Atrial Strain to Predict Postoperative Atrial Fibrillation in Patients Undergoing Off-pump Coronary Artery Bypass Graft

OBJECTIVE

Postoperative atrial fibrillation (POAF) is associated with increased morbidity, mortality, and length of hospital stay. The objective of this study was to assess the utility of left atrial strain (LAS) to predict POAF in patients undergoing off-pump coronary artery bypass grafting (OPCABG).

DESIGN

Retrospective observational study.

SETTING

Tertiary care hospital.

PARTICIPANTS

103 patients undergoing OPCABG.

INTERVENTIONS

None.

MEASUREMENTS AND RESULTS

In addition to comprehensive transthoracic echocardiography, LAS was measured for reservoir (R), conduction (CD), and contraction (CT) components. POAF was defined as new electrocardiographic evidence of AF requiring treatment. Logistic regression was done to assess factors associated with POAF. The diagnostic accuracy of variables in predicting POAF was assessed by receiver operating characteristic analysis. POAF was documented in 24 (23.3%) patients. There was no difference in ejection fraction, average global longitudinal strain, or proportion of left ventricular diastolic dysfunction grades between patients with POAF and patients without POAF. All three components of LAS: LAS R (19.2 ± 4.7 v 23.5 ± 4.8, p < 0.001), LAS CD (8.9 ± 3.7 v 12.3 ± 4.8, p = 0.1), and LAS CT (10.3 ± 3.9 v 12.1 ± 4.1, p = 0.04), were significantly lower among patients with POAF compared with patients without POAF, respectively. According to univariate analysis, all components of LAS were statistically significant predictors of POAF. In multivariate analysis, only age (odds ratio = 1.08, p = 0.025) and LAS R (odds ratio = 0.84, p = 0.004) were independently associated with POAF. LAS R was a better predictor of POAF, with an area under the curve (AUC) of 0.758, than LAS CD (AUC = 0.67) and LAS CT (AUC = 0.62). LAS R had an optimal cutoff of 23% with sensitivity of 95.8% (confidence interval: 78.9-99.9%) and specificity of 49.4% (37.9-60.9%) to predict POAF.

CONCLUSIONS

LAS R is a significant predictor of POAF, and its use can be recommended for screening of OPCABG patients at high risk of POAF.

Left Atrial Strain to Predict Postoperative Atrial Fibrillation in Patients Undergoing Coronary Artery Bypass Grafting

BACKGROUND

Postoperative atrial fibrillation (POAF) is a common complication after cardiac surgery being associated with poorer outcomes. Revealing before the operation of left atrial subtle structural/functional abnormalities may help to identify patients at increased risk of POAF. We investigated the role of left atrial strain parameters by preoperative speckle tracking echocardiography as independent predictors of POAF in patients undergoing coronary artery bypass graft.

METHODS

Consecutive patients undergoing isolated coronary artery bypass graft were prospectively enrolled at three Italian centers. All patients underwent transthoracic echocardiography before the operation. The occurrence of POAF up to discharge was monitored.

RESULTS

Overall, a total of 310 patients were included. POAF was demonstrated in 103 patients (33%). At receiver operating characteristic curve analysis, lower global peak atrial longitudinal strain (PALS) values significantly predicted the risk of POAF (area under the curve, 0.74; P<0.001). The optimal cutoff value for the arrhythmia prediction was a global PALS value <28%, with a specificity of 86% and a sensitivity of 36%. The incidence of POAF was 51% in patients with global PALS <28% versus 14% in those with PALS ≥28% (P<0.001), with a POAF-free survival at Kaplan-Meier analysis of 45.4% and 85.7%, respectively (P<0.001). At multivariate analysis, a global PALS <28% carried a 3.6-fold higher risk of POAF (hazard ratio, 3.6 [95% CI, 2.2-5.9]; P<0.001). The risk increase was even higher when PALS <28% was associated with age ≥70 years (adjusted hazard ratio, 11.2 [4.7-26.6], P<0.001).

CONCLUSIONS

A presurgery global PALS <28% is a specific parameter to stratify patients at increased risk of POAF after coronary artery bypass graft. This assessment can be useful to identify patients at higher arrhythmic risk in whom perioperative preventive strategies and stricter monitoring aimed at early diagnosing and treating POAF may be applied.

Outcomes of Coronary Artery Bypass Graft Surgery in Africa: A Systematic Review and Meta-Analysis

Coronary artery bypass graft (CABG) surgery has been in practice for many decades, and it is one of the most commonly performed cardiac surgeries worldwide. While there are several studies reporting data on perioperative outcomes following CABG in developed countries, there is a staggering paucity of data and evidence reporting the outcomes in developing areas such as Africa. Thus, it is important to study the practice and outcome of CABG in Africa to establish its clinical efficacy and safety in this region and identify factors that might be limiting its practice. The overall aim of this study is to identify all relevant clinical data on CABG in Africa and report on the perioperative outcomes and practice of CABG in the African population. Electronic search was performed using three online databases, PubMed, African Journal Online, and Research Gate, from inception to June 2023. The preferred reporting items for systematic reviews and meta-analysis (PRISMA) guideline was utilised for this study. Relevant studies fulfilling predefined eligibility criteria were included in the study. Intraoperative details, such as the number of grafts performed, operative, bypass, and cross-clamp time, were reported. The primary endpoint assessed were early mortality and overall mortality. The secondary endpoints included length of hospital stay, intensive care unit stay, and postoperative complications, such as renal impairment, atrial fibrillation, and surgical site infection. The data were pooled together and meta-analyzed using a random effect model for proportions and mean for meta-analysis with R software (version 4.3.1 (2023-06-16); R Development Core Team, Vienna, Austria). This systematic review identified 42 studies that fulfilled the study eligibility criteria, including 21 randomised controlled trials, 20 observational studies, and one cross-sectional study. Only four out of the 54 countries in Africa had studies carried out that met the criteria for this review; they included Algeria, Egypt, Nigeria, and South Africa, with a majority from Egypt. Meta-analysis reported a pooled early mortality and pooled overall mortality of 3.51% and 3.73%, respectively, for the total cohort of patients. The result of this meta-analysis suggests that mortality outcomes following CABG in Africa are relatively higher than those in developed nations. Several issues, such as lack of financial resources and poor infrastructure, continue to hinder the optimal practice of CABG procedures in many parts of Africa. Further studies focused on finding factors associated with outcomes following CABG should be done. Though there were a few limitations to the study largely from a lack of data from several regions and countries in Africa, the result from this meta-analysis can serve as a benchmark for future studies until more relevant data are reported.