Perioperative Beta-Blocker for Atrial Fibrillation after Cardiac Surgery: A Meta-Analysis

Background This meta-analysis was conducted to evaluate the impact of perioperative use of beta-blocker (BB) on postoperative atrial fibrillation (POAF) after cardiac surgery other than isolated coronary artery bypass grafting (CABG).

Methods Five online databases were searched. Studies were included if they (1) enrolled patients who underwent cardiac surgery other than isolated CABG and (2) demonstrated the impact of perioperative use of BB on POAF based on the randomized controlled trial or adjusted analysis. The primary outcome was the occurrence rates of POAF after cardiac surgery. A meta-regression and subgroup analysis were performed according to the proportion of patients with cardiac surgery other than isolated CABG and the timing of BB use, respectively.

Results Thirteen articles (5 randomized and 8 nonrandomized studies: n = 25,496) were selected. Proportion of enrolled patients undergoing cardiac surgery other than isolated CABG ranged from 7 to 100%. The BBs were used in preoperative, postoperative, and both periods in 5, 5, and 3 studies, respectively. The pooled analyses showed that the risk of POAF was significantly lower in patients with perioperative BB than those without (odds ratio, 95% confidence interval = 0.56, 0.35–0.91 and 0.70, 0.55–0.91 in randomized and nonrandomized studies, respectively). The risk of POAF was lower in the BB group irrespective of the proportion of nonisolated CABG. Benefit regarding in-hospital mortality was inconclusive. Perioperative stroke and length of stay were not significantly different between BB and non-BB groups.

Conclusions Perioperative use of BB is effective in preventing POAF even in patients undergoing cardiac surgery other than isolated CABG, although it did not translate into improved clinical outcomes.

Perioperative risk factors of acute kidney injury after non-cardiac surgery: A multicenter, prospective, observational study in patients with low grade American Society of Anesthesiologists physical status

BACKGROUND

The aim of this study was to determine the incidence and the perioperative risk factors of acute kidney injury (AKI) using "Kidney Disease: Improving Global Outcomes" (KDIGO) guidelines, in patients with low grade American Society of Anesthesiologists physical status (ASA-PS) undergoing non-cardiac surgery.

METHODS

In this multicenter, prospective, observational study, 870 surgical patients older than 40 years with ASA-PS I-II who underwent noncardiac surgery, were included. The primary outcome of this study was perioperative AKI defined by the KDIGO criteria.

RESULTS

AKI was detected in 49 (5.63%) of the patients. Multivariate analysis detected the presence of preoperative hypertension (aOR = 0.130; CI = 0.030-0.566; p = 0.007) and intraoperative transfusion of erythrocytes (aOR = 0.076; CI = 0.008-0.752; p = 0.028) as independent predictors of postoperative AKI development.

CONCLUSION

Approximately, 6% of patients with ASA I-II presenting for noncardiac surgery developed postoperative AKI. Preoperative hypertension and intraoperative erythrocyte transfusion are independent predictors of AKI after non-cardiac surgery in this patient population.

Effect of Preoperative Beta-Blocker Use on Outcomes Following Cardiac Surgery

Recent studies suggest that the use of preoperative β blockers in cardiac surgery may not provide improved mortality rates and may even contribute to negative clinical outcomes. We therefore assessed the role of β blockers on several outcomes after cardiac surgery (delirium, acute kidney injury [AKI], stroke, atrial fibrillation (AF), mortality, and hospital length of stay) in 4,076 patients who underwent elective coronary artery bypass grafting, coronary artery bypass grafting + valve, or valve cardiac surgery from November 1, 2009, to September 30, 2015, at Vanderbilt Medical Center. Clinical data from 2 prospectively collected datasets at our institution were reviewed: the Cardiac Surgery Perioperative Outcomes Database and the Society of Thoracic Surgeons Database. Preoperative β-blocker use was defined by Society of Thoracic Surgeons guidelines as patients receiving a β blocker within 24 hours preceding surgery. Of the included patients, 2,648 (65.0%) were administered a β blocker within 24 hours before surgery. Adjusting for possible confounders, preoperative β-blocker use was associated with increased odds of AKI stage 2 (odds ratio 1.96, 95% confidence interval 1.19 to 3.24, p <0.01). There was no evidence that β-blocker use had an independent association with postoperative delirium, AKI stages 1 and 3, stroke, AF, mortality, or prolonged length of stay. A secondary propensity score analysis did not show a marginal association between β-blocker use and any outcome. In conclusion, we did not find significant evidence that preoperative β-blocker use was associated with postoperative delirium, AF, AKI, stroke, or mortality.