Atrial fibrillation - Can HbA1c levels really predict the risk?

Risk Scores for Prediction of Postoperative Atrial Fibrillation After Cardiac Surgery: A Systematic Review and Meta-Analysis

Postoperative atrial fibrillation (POAF) is a common complication after cardiac surgery and is associated with poor clinical outcomes. The objective of this systematic review and meta-analysis was to assess the performance of risk scores to predict POAF in cardiac surgery patients. We searched MEDLINE, Embase, and Cochrane CENTRAL for studies that developed/evaluated a POAF risk prediction model. Pairs of reviewers independently screened studies and extracted data. We pooled area under the receiver operating curves (AUCs), sensitivity and specificity, and adjusted odds ratios from multivariable regression analyses using the generic inverse variance method and random effects models. Forty-three studies (n = 63,847) were included in the quantitative synthesis. Most scores were originally developed for other purposes but evaluated for predicting POAF. Pooled AUC revealed moderate POAF discrimination for the EuroSCORE II (AUC 0.59, 95% confidence interval [CI] 0.54 to 0.65), Society of Thoracic Surgeons (AUC 0.60, 95% CI 0.56 to 0.63), EuroSCORE (AUC 0.63, 95% CI 0.58 to 0.68), CHADS2 (AUC 0.66, 95% CI 0.57 to 0.75), POAF Score (AUC 0.66, 95% CI 0.63 to 0.68), HATCH (AUC 0.67, 95% CI 0.57 to 0.75), CHA2DS2-VASc (AUC 0.68, 95% CI 0.60 to 0.75) and SYNTAX scores (AUC 0.74, 95% CI 0.71 to 0.78). Pooled analyses at specific cutoffs of the CHA2DS2-VASc, CHADS2, HATCH, and POAF scores demonstrated moderate-to-high sensitivity (range 46% to 87%) and low-to-moderate specificity (range 31% to 70%) for POAF prediction. In conclusion, existing clinical risk scores offer at best moderate prediction for POAF after cardiac surgery. Better models are needed to guide POAF risk stratification in cardiac surgery patients.

Incidence, predictors, and outcome for post-operative atrial fibrillation in Indian patients undergoing off-pump coronary artery bypass grafting-a prospective observational study

Purpose

Indian patients who undergo surgical revascularization are relatively younger than their Western counterparts and are predominantly revascularized using off-pump coronary artery bypass grafting (OPCAB) technique. They may therefore be at a reduced risk of developing post-operative atrial fibrillation (POAF). The aim of this study was to assess the incidence of POAF, measure its impact on outcomes, and identify the predictors for POAF in the Indian patients undergoing OPCAB. Besides, the ability of European System for Cardiac Operative Risk Evaluation (EuroSCORE) and Society of Thoracic Surgeons (STS) scores in predicting POAF was also assessed.

Methods

In this prospective observational study, all patients undergoing isolated OPCAB in a single institution over a 12-month period were included. Patients undergoing re-operative surgery, emergency procedure, concomitant surgery, or those with history of previously diagnosed or treated atrial fibrillation were excluded. Logistic regression was performed to identify the predictors of POAF. The receiver operating characteristic (ROC) curve was used to determine the ability of EuroSCORE and STS scores to assess risk of developing POAF.

Results

We recruited 1108 patients in the study of which 88 (7.94%) patients developed POAF. Age (OR = 1.082, p < 0.001, 95%CI: 1.050-1.114), unstable angina (OR = 16.32, p = 0.036, 95%CI: 1.2-221.4), presence of diabetes mellitus (OR 1.781, p = 0.025, 95%CI: 1.074-2.955), left atrial size (OR 2.506, p = 0.001, 95%CI: 1.478-4.251), and presence of chronic renal failure (OR 8.7, p = 0.001, 95%CI: 2.4-31.53) were significant predictors of POAF. Both the EuroSCORE (p = 0.035) and the STS score (p = 0.001) were significantly higher in patients developing POAF. The area under the ROC curve for the EuroSCORE II was 0.62 and for the STS score was 0.64 suggesting satisfactory and similar discriminatory power of both the scores to predict POAF in these patients. POAF was associated with significantly increased adverse outcomes like stroke and prolonged hospital stay.

Conclusions

In our study, the incidence of POAF was much lower (7.94%) than that reported previously. POAF significantly increased adverse outcomes and length of hospital stay. Both EuroSCORE II and STS scores had similar discriminating power in predicting POAF.