Prophylaxis against atrial fibrillation after cardiac surgery: effective, but not routinely used--a survey of cardiothoracic units in the United kingdom

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.

Topical amiodarone during cardiac surgery: Does epicardial application of amiodarone prevent postoperative atrial fibrillation?

OBJECTIVES

Atrial fibrillation (AF) is a common complication after cardiac surgery. Topical amiodarone on the epicardium may help prevent postoperative AF while avoiding the side effects of its systemic administration. The purpose of this study was to evaluate the all-comer strategy of epicardial amiodarone application for the prevention of postoperative AF.

METHODS

A retrospective observational study was performed that evaluated the incidence of new-onset AF in a consecutive series of cardiac surgery patients who were treated with either no amiodarone (historical control, n = 100), epicardial application of amiodarone mixed in a topical hydrogel (n = 50), or epicardial application of an amiodarone-soaked sealant patch (n = 50). Perioperative data were compared between the 3 groups, with all patients receiving continuous postoperative telemetry to monitor for new-onset AF.

RESULTS

The cohort consisted of 200 cardiac surgery patients (coronary bypass 82%, valve surgery 24%) who had no history of AF (mean age 71.0 years, 28% female). Among the 3 groups, the incidence of postoperative AF did not significantly differ, with 29 of 100 (29%) patients in the historical control group having new AF, compared with 18 of 50 (36%) in the amiodarone-hydrogel group, and 18 of 50 (36%) in the amiodarone-patch group (P = .56). The results did not differ when the analysis was restricted to coronary bypass patients only (n = 142, 27% vs 38% vs 32%, no-amiodarone vs amiodarone-hydrogel vs amiodarone-patch, respectively, P = .56). In multivariate logistic regression analysis, only older age (P = .001) was significantly associated with new-onset AF, but the use of topical amiodarone was not.

CONCLUSIONS

Routine epicardial application of topical amiodarone was not associated with a reduction in the incidence of new-onset postoperative AF in this observational study of older patients, leading us to question its role in contemporary cardiac surgical practice.

Dexmedetomidine sedation reduces atrial fibrillation after cardiac surgery compared to propofol: a randomized controlled trial

BACKGROUND

Atrial fibrillation occurs frequently in patients following cardiac surgery and can be a cause of increased morbidity and mortality. The use of dexmedetomidine to prevent atrial fibrillation is unclear. The present study was designed to evaluate the effect of dexmedetomidine sedation on the incidence of atrial fibrillation after cardiac surgery.

METHODS

Upon arrival to the intensive care unit (ICU), cardiac surgery patients without prior atrial fibrillation or flutter were randomized to receive either dexmedetomidine (0.2-1.5 μg/kg/h) or propofol (0.3-3 mg/kg/h) open-label titrated to a target Richmond agitation-sedation scale of 0 to -3. Our primary endpoint was the incidence of postoperative atrial fibrillation, and the secondary end points were the length of ICU stay, length of hospital stay, and hospital costs.

RESULTS

Atrial fibrillation occurred in 6 of 44 patients (13.6 %) in the dexmedetomidine group compared to 16 of 44 patients (36.4 %) in the propofol group (odds ratio = 0.28; 95 % confidence interval, 0.10, 0.80; P = 0.025). The median (interquartile range) length of ICU stay in the dexmedetomidine group was significantly lower than in the propofol group (2.9 (2.4-3.5) vs 3.5 (2.7-4.5 days, P = 0.008), with a trend toward a decrease in median hospital costs (86,367 vs 77,874 Chinese yuan; P = 0.068). The incidence of hypotension was higher in the dexmedetomidine group than in the propofol group (25/44 (56.8 %) vs 13/44 (29.5 %); P = 0.017).

CONCLUSIONS

Dexmedetomidine sedation reduced the incidence of new-onset postoperative atrial fibrillation and shortened the length of ICU stay in patients after cardiac surgery compared to propofol sedation. Dexmedetomidine treatment was associated with more episodes of hypotension.

TRIAL REGISTRATION

chictr.org.cn: ChiCTR-IPR-16008231 , retrospectively registered: April 6, 2016. This trial was not prospectively registered due to a lack of importance applied to trial registration.

Increased left ventricular myocardial mass is associated with arrhythmias after cardiac surgery

OBJECTIVES

The purpose of this study was to investigate whether patients with an elevated left ventricular mass index undergoing cardiac surgery were more likely to experience postoperative atrial and ventricular arrhythmias.

DESIGN

A retrospective analysis.

SETTING

A single tertiary care university hospital.

PARTICIPANTS

One thousand consecutive patients undergoing all types of adult cardiac surgery.

INTERVENTIONS

With institutional review board approval, intraoperative transesophageal echocardiographic images were reviewed by a single reviewer. The left ventricular mass index was calculated using the American Society of Echocardiography-recommended formula. Medical charts were reviewed for the occurrence and type of clinically significant postoperative arrhythmias.

MEASUREMENTS AND RESULTS

Of the patients who had an elevated left ventricular mass index, 47.6% (225/473) developed clinically significant postoperative arrhythmias compared with 38.3% (142/371) of patients with a normal left ventricular mass index (odds ratio [OR] = 1.46; 95% confidence interval [CI], 1.11-1.93; p = 0.007). In the multivariate analysis, this finding remained statistically significant, controlling for the effects of age, weight, sex, surgery type, left ventricular function, functional status, left atrial dimensions, and a history of atrial fibrillation (OR = 1.40; 95% CI, 1.03-1.90 per 100-g/m(2) increase in the left ventricular mass index). An increased left ventricular mass index was also an independent predictor of the separate or combined occurrence of atrial or ventricular arrhythmias.

CONCLUSIONS

An elevated left ventricular mass index was a strong independent predictor of clinically significant postoperative atrial and ventricular arrhythmias after adult cardiac surgery. Although prospective validation is required, targeting patients for arrhythmia prophylaxis therapy may be justified in patients with a left ventricular mass index >188 g/m(2).