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Rademacher et al. Vessel Plus 2022;6:39 https://dx.doi.org/10.20517/2574-1209.2021.138 Page 3 of 9

Search strategy for the identification of publications
We performed a PubMed search to identify pertinent literature on POAF and stroke as an outcome in
patients undergoing cardiac surgery. The following search term was created to identify eligible publications:
{(“Cardiac Surgical Procedures”[Mesh] OR “heart surgery”[tiab] OR “cardiac surgery”[tiab]) AND (“Atrial
Fibrillation”[Mesh] OR “atrial fibrillation”[tiab]) AND “postoperative” AND “anticoagulation” NOT
“percutaneous”[tiab] NOT “transcatheter”[tiab]} OR {(“Cardiac Surgical Procedures”[Mesh] OR “heart
surgery”[tiab] OR “cardiac surgery”[tiab]) AND (“Atrial Fibrillation”[Mesh] OR “atrial fibrillation”[tiab])
AND “postoperative” AND “stroke” NOT “percutaneous”[tiab] NOT “transcatheter”[tiab]}. We included
English-language studies published any time through July 2021, the last month studied. Peer-reviewed
journal papers and conference proceedings papers were included; extended abstracts were excluded.
Additionally, we evaluated bibliographies of retrieved studies.

RESULTS
Evidence on POAF and stroke
Our initial literature search yielded 889 articles, of which 199 were reviewed in more detail to compile
evidence on the association between POAF and stroke. A large number of retrospective and some
prospective, observational studies have focused on this association. In addition, several randomized-clinical
trials designed to evaluate the safety and efficacy of various interventions to prevent POAF has also reported
on postoperative strokes stratified by incident POAF. That data should also be considered observational.
Over the last decade, there have been 8 meta-analyses [Table 1] providing pooled estimates of the stroke risk
associated with POAF in patients undergoing cardiac surgery [11-18] . Five meta-analyses were published within
12 months of our literature search [14-18] . The included studies in the meta-analyses to obtain pooled estimates
vary considerably. However, the association of POAF with an elevated risk of stroke is directionally
(qualitatively) consistent across all studies [Table 1 shows pooled odds ratios (OR) ranging from 1.62 to
4.09].

[11]
In 2013, Hernandez et al. reported on the association of obesity and POAF in 18 studies and included a
subgroup analysis of 10 studies that also reported cumulative incidence of stroke during follow-up. The
[12]
pooled OR for stroke was 1.77 (1.36-2.31). In 2017, Megens et al. conducted a meta-analysis of studies on
the association of POAF and long-term stroke in patients undergoing CABG. Long-term stroke was defined
as stroke after 6 months or greater following CABG with a median follow-up period of 2.05 years.
Outcomes were pooled on the log-ratio scale using a random-effects model and reported as exponentiated
effect-sizes. They reported a pooled estimate for the OR of the cumulative incidence of stroke during follow-
up of 1.36 (1.12-1.65), including 16 studies. In a separate analysis, the authors also pooled adjusted risk
estimates reporting a pooled effect estimate of 1.25 (1.09-1.43). The level of adjustment varied considerably
between the studies and resulted in inconsistent changes in the effect estimate compared to the unadjusted
estimates .
[12]
The next meta-analysis was published in 2019 by Lin et al. included only 8 studies on patients undergoing
[13]
CABG and/or valve procedures and one non-cardiac surgery study on the association of POAF and stroke.
Further, they divided studies based on stroke occurrence within the first 30 days after surgery or thereafter.
The pooled estimate for the 30-day stroke OR was 1.62 (1.47-1.80) (6 studies), and lower at 1.37 (1.07-1.77)
for the follow-up after 30 days (4 studies).

The remaining 5 meta-analyses were all published within 12 months of our literature search. Kerwin et. al
[14]
included 12 studies in an unadjusted OR analysis [pooled OR 2.15 (1.82-2.53)] in patients after CABG, and
3 studies for a pooled estimate of adjusted OR for stroke [1.88 (1.02-3.46)]. Woldendorp et al. published
[15]