Comparison of novel oral anticoagulants versus warfarin for post-operative atrial fibrillation after coronary artery bypass grafting

Enhanced Recovery After Surgery Cardiac Society turnkey order set for prevention and management of postoperative atrial fibrillation after cardiac surgery: Proceedings from the American Association for Thoracic Surgery ERAS Conclave 2023

Background

Postoperative atrial fibrillation (POAF) is a prevalent complication following cardiac surgery that is associated with increased adverse events. Several guidelines and expert consensus documents have been published addressing the prevention and management of POAF. We aimed to develop an order set to facilitate widespread implementation and adoption of evidence-based practices for POAF following cardiac surgery.

Methods

Subject matter experts were consulted to translate existing guidelines and literature into a sample turnkey order set (TKO) for POAF. Orders derived from consistent class I or IIA or equivalent recommendations across referenced guidelines and consensus manuscripts appear in the TKO in bold type. Selected orders that were inconsistently class I or IIA, class IIB, or supported by published evidence appear in italic type.

Results

Preoperatively, the recommendation is to screen patients for paroxysmal or chronic atrial fibrillation and initiate appropriate treatment based on individual risk stratification for the development of POAF. This may include the administration of beta-blockers or amiodarone, tailored to the patient's specific risk profile. Intraoperatively, surgical interventions such as posterior pericardiotomy should be considered in selected patients. Postoperatively, it is crucial to focus on electrolyte normalization, implementation strategies for rate or rhythm control, and anticoagulation management. These comprehensive measures aim to optimize patient outcomes and reduce the occurrence of POAF following cardiac surgery.

Conclusions

Despite the well-established benefits of implementing a multidisciplinary care pathway for POAF in cardiac surgery, its adoption and implementation remain inconsistent. We have developed a readily applicable order set that incorporates recommendations from existing guidelines.

Half-dose direct oral anticoagulation versus warfarin for atrial fibrillation following cardiac surgery

BACKGROUND

Optimal anticoagulation strategies have not been defined for patients with atrial fibrillation following cardiac surgery.

METHODS

From a total cohort of 228 patients with pre-existing or new onset atrial fibrillation following coronary artery bypass grafting and/or valve surgery, we compared in-hospital and 30-day outcomes in 119 patients treated with low-dose aspirin and a half-dose direct oral anticoagulant (DOAC) versus 109 treated with low-dose aspirin and warfarin.

RESULTS

DOAC patients were older (73.1±7.0 vs. 68.7±11.4 years, P<0.001) and had a lower incidence of preoperative atrial fibrillation (37 [31.1%] vs. 69 [63.3%], P<0.001). Otherwise, the two cohorts were well matched for baseline demographics, cardiovascular risk factors, comorbidities, prior cardiac history and STS Risk Score. In comparison to Warfarin patients, DOAC patients had a shorter length of post-surgical stay (6 [5-8] vs. 7 [5-10] days, P=0.037). The two cohorts, however, had a similar incidence of stroke, transient ischemic attack, reoperation for bleeding and postoperative blood bank product usage. Follow-up 30-day outcomes did not differ between the two groups with respect to mortality (0 [0.0%] vs. 0 [0.0%], P=1.000) and hospital readmission (16 [13.4%] vs. 14 [12.8%], P=0.893), although two DOAC patients required drainage of sanguineous pericardial effusions.

CONCLUSIONS

In comparison to warfarin, half-dose DOAC anticoagulation in patients with atrial fibrillation following cardiac surgery is associated with a shorter postoperative length of stay, without a significant increase in stroke/transient ischemic attack, reoperation for bleeding or postoperative blood product transfusion. Follow-up echocardiography in anticoagulated patients is recommended to rule out significant sanguineous pericardial effusions in the early postoperative period following hospital discharge.

Anticoagulant Prescribing Patterns in New-Onset Atrial Fibrillation After Cardiac Surgery

BACKGROUND

Postoperative atrial fibrillation (POAF) is a common complication after cardiac surgery and is associated with an increased risk of thromboembolic stroke. Recommendations regarding the optimal anticoagulant, timing of initiation, and duration of therapy remain uncertain.

METHODS

Administrative databases were used to include adult patients who presented with POAF after cardiac surgery between January 1, 2015, and December 31, 2020. Key exclusion criteria included preexisting atrial fibrillation, mechanical valve replacement, or anticoagulant prescription fill within 6 months before the index admission.

RESULTS

A total of 3214 of patients were included, and 878 (27.3%) were prescribed an oral anticoagulant (OAC) on discharge, with 536 (61%) prescribed warfarin and 342 (39%) prescribed a direct OAC. More than half of the patients (56.1%) stopped their OAC by 6 months. There was no difference in stroke or systemic embolism at 30 days, 3 months, or 6 months between those with and without anticoagulation prescribed. However, those on any OAC had higher rates of any bleeding at all time points.

CONCLUSIONS

A minority of patients who presented with POAF after cardiac surgery were prescribed OAC, with warfarin being the most common agent. OAC initiation was associated with increased bleeding risk, warranting special consideration when assessing a patient's risk of stroke with the increased risk of bleeding, particularly in the postoperative period.

Atrial fibrillation following coronary artery bypass graft: Where do we stand?

Atrial fibrillation (AF) is the most common atrial arrhythmia following coronary artery bypass graft (CABG). Its prevalence is 15-45% and is associated with poor long-term prognosis. Risk factors can be patient-related, intraoperative, and/or postoperative. Therapeutic and preventive strategies have been developed to curtail AF burden. Cardioversion is recommended for unstable or symptomatic patients and rate control if asymptomatic. Anticoagulation is challenging with risk of thromboembolism and bleeding. However, patients should be anticoagulated after cardioversion or if AF persists >48 h and risk factors of stroke exist. A minimum of 4 weeks is recommended but longer duration should be considered in patients at high risk of stroke irrespective of recurrence of AF.