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Page 2 of 9 Rademacher et al. Vessel Plus 2022;6:39 https://dx.doi.org/10.20517/2574-1209.2021.138

Keywords: Postoperative atrial fibrillation, anticoagulation, stroke, cardiac surgery

INTRODUCTION
Patients undergoing cardiac surgery commonly develop postoperative atrial fibrillation (POAF) . The
[1,2]
exact pathophysiology of atrial fibrillation and its origins remains poorly understood, but an increasing
body of evidence points towards an inflammatory process propagated and sustained by anatomic
[3]
remodeling of the atria . An inflammatory response is believed to be both a trigger for atrial fibrillation as
well as a consequence of atrial fibrillation. Patients subject to cardiac surgery are exposed to a host of insults
that predispose them to POAF. These include the inflammatory cascade triggered by the stress responses to
perioperative physiological changes and direct tissue trauma. Direct trauma to atrial tissue results from
ischemia, incisions, and other surgical manipulation, while tissue stretch due to a change in loading
conditions in the perioperative period and electrolyte disturbances .
[4,5]
The incidence of POAF is thought to vary based on the type of procedure as well as predisposing factors.
Reports show the incidence of POAF ranges from approximately 20% after coronary artery bypass graft
(CABG) surgery to as high as 50% after combined CABG and valve surgery, with the most significant
predisposing risk factors being age, male sex, history of heart failure, peripheral arterial disease, and
previous stroke .
[5-7]

Though often self-limited and partially preventable, it continues to significantly affect outcomes after
cardiac surgery . POAF has been associated with an increased incidence of heart failure, reintubation,
[8]
length of hospital stay, hospital costs, and long-term all-cause mortality [1,5-7] . Atrial fibrillation is strongly
associated with stroke, other morbidities, and mortality in the general population . This is particularly
[9]
pronounced in patients with additional risk factors and has led to guideline recommendations to use oral
[9]
anticoagulation in patients with atrial fibrillation persisting for 48 hours or longer . Whether POAF carries
the same morbidity and mortality as other atrial fibrillation due to or associated with other causes remains
controversial. Robust evidence for the management of postoperative atrial fibrillation is lacking.

Here we present a systematic literature review of the association between POAF and stroke and the evidence
for the use of anticoagulation in the setting of POAF to prevent stroke.

METHODS
The preferred reporting items for systematic reviews and meta-analyses (PRISMA) guidelines were followed
to perform a systematic review of the literature on the association between POAF and stroke, including the
evidence for the benefits and harms of anticoagulation for the specific purpose of preventing stroke in the
[10]
setting of POAF .

Definitions
A major challenge in the literature is the inconsistent definition of POAF as well as methods used to detect
it in all phases of care. For studies to be included in this systematic review, any definition of POAF and
duration was acceptable. Clinical and imaging-based stroke definitions were permissible, including ischemic
and non-ischemic strokes, disabling, non-disabling strokes, and transient ischemic attacks. All classes and
any duration of anticoagulants used postoperatively studied and reported were included in this review.