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Page 2 of 5 Bilfinger. Vessel Plus 2022;6:40 https://dx.doi.org/10.20517/2574-1209.2021.118

changed. Although no longer debated if it affects outcomes (it does), and despite its frequency, there
remains considerable uncertainty how to deal with practical issues on a daily basis. The following are
reflections from the view-point of the practicing surgeon.

QUESTIONS ASKED IN PRE-OP ATRIAL FIBRILLATION
One of the first questions to deal with in a patient deemed in need of cardiac surgery who also has AF is
how to handle the anticoagulation. Most patients are either on warfarin or a novel anticoagulant (NOAC)
with or without an antiplatelet agent. Interruption of anticoagulation has been studied predominantly for
non-cardiac surgical procedures. A meta-analysis looking specifically at the interruption of NOAC’s in
patients with AF found that interruption was associated with 0.4% thromboembolic and 1.8% major
[2]
bleeding events at 30 days post surgery . Guidelines for the perioperative interruption of anticoagulation
particularly in cardiac surgery exist, but are buried within other categories of patients . Urgency and the
[3,4]
type of procedure planned are likely to play a major role, but are less well addressed. Recommendations to
questions such as how many days in advance of surgery should anticoagulants be held, are there patients
who need to be converted to intra-venous Heparin, hence admitted early, what lab test and when should be
[4]
obtained in order to maximize safety and avoid costly cancellations, exist , but details are often
institutionally protocolized [3,5,6] . The impact of case urgency in AF patients on anticoagulation has never
been evaluated.

It has been reported that AF in healthy patients without structural heart problems or other comorbidities
seems not to affect longevity . This is not the case for the vast majority of cardiac patients and appears to
[7]
have the most impact on patients with valvular heart disease. A study from Canada found that the
prevalence of AF in patients requiring heart surgery reached from 11.3% for coronary artery bypass grafting
(CABG) to 30% for valve cases and that preoperative AF was associated with decreased event free survival
(adjusted hazard ratio 1.55) . An other large prospective study from Australia showed that short and long-
[8]
term outcomes were worse in patients requiring valve surgery for non-rheumatic disease with 15% less
survival at 10 years in AF patients. The study did not distinguish patients who did or did not receive ablative
[9]
therapy . The next question in an AF patient needing heart surgery is, are there any technical
considerations in the conduct of the planned operation which need to be added or altered because of AF? In
other words should the AF be addressed, and if so when: before or after the planned procedure? Here we
have some help from STS guidelines: quote from the executive summary: “ Surgical ablation for AF can be
performed without additional risk of operative mortality or major morbidity, and is recommended at the
time of concomitant mitral operations to restore sinus rhythm. (Class I, Level A) Surgical ablation for AF
can be performed without additional operative risk of mortality or major morbidity, and is recommended at
the time of concomitant isolated aortic valve replacement, isolated coronary artery bypass graft surgery, and
aortic valve replacement plus coronary artery bypass graft operations to restore sinus rhythm. (Class I, Level
B nonrandomized). Further, it is reasonable to perform left atrial appendage excision or exclusion in
conjunction with surgical ablation for AF for longitudinal thromboembolic morbidity prevention. (Class
IIA, Level C limited data) At the time of concomitant cardiac operations in patients with AF, it is reasonable
to surgically manage the left atrial appendage for longitudinal thromboembolic morbidity prevention. (Class
[9]
IIA, Level C expert opinion)” . It is clear that surgical ablative therapy carries the highest success rates
when performed in conjunction with mitral procedures. In the United States this therapy is now applied to
the majority of AF patients requiring mitral procedures [> 60%]. In expert hands post-op AF in these
procedures, the most favorable category, has decreased by 50% at the cost of a greater likelihood of requiring
a permanent pacemaker . In all other categories the likelihood of an AF patient receiving a concomitant
[10]
surgical ablation is only about half of that for mitral procedures [11,12] . The success rate seems to be lower in
some studies, which is attributed to the fact that it is inherently a different procedure because the atria are