Four studies evaluated the effectiveness of various therapies for preventing postoperative atrial fibrillation. Two randomized controlled trials found no significant difference between amiodarone and metoprolol, or between dexamethasone and placebo, in reducing atrial fibrillation. However, atorvastatin was found to significantly reduce postoperative atrial fibrillation compared to placebo. Additionally, ranolazine combined with amiodarone accelerated the conversion of new-onset atrial fibrillation compared to amiodarone alone. The studies demonstrated mixed results on the effectiveness of therapies for preventing postoperative atrial fibrillation.

1. Prevention of Postoperative
Atrial Fibrillation
April 7, 2016
NYU Adult-Gerontology Acute Care III
Jennifer Stieber

2. Setting: CV/Thoracic Surgery Post-op unit

3. HPI
This is Martha, 64 y.o. female with history of
CAD s/p stents in Oct 2016, HLD, HTN, TR,
sleep apnea, insomnia, anxiety, overactive
bladder, GERD, lap band removed due to
perforation, who presented with cough and
fatigue for several weeks, and was treated for
RUL pneumonia and abscess as an outpatient
with azithromcycin, followed by prednisone and
levaquin without improvement. She was referred
to thoracic surgery and was admitted for a R
thoracotomy and R upper lobe resection.

4. Home meds:
lipitor 20mg po daily
cymbalta 60mg daily
ASA 81 mg daily
clopidogrel 75 mg daily
Social:
No EtOH
No tobacco
Retired teacher
Lives with husband in Brooklyn
NKDA

5. Hospital course:
3/9- admitted, IV tygacil started. 3/10 echo done. 3/12 - R upper lobectomy
without complications, chest tube placed 3/13 - transferred to POU, hypotension
and low UO treated with IVF, albumin, lasix, neo. 3/14 - afib with RVR to 120s,
7.5mg metoprolol, amio load and drip. Neo for BP support. 3/15 - NSR, neo off,
transitioned to PO amio, heparin gtt started. lung tissue culture shows moderate
Strep intermedius, sputum with H. influenzae 3/16 PICC placed for long term IV
abx 3/17 - doing well with PT heparin drip continued 3/18 - doing well with PT.
Heparin drip off. 3/19 - chest tube remains with +airleak

6. Physical Exam
General appearance: Alert female sitting up in
chair, no acute distress
Neck: supple, midline
Lungs: clear to auscultation bilaterally, R CT to
water seal. No crepitus.
Heart: S1, S2, regular rate and rhythm
Abdomen: soft, nontender, nondistended
Extremities: +1 edema to bilateral lower legs,
warm and well perfused throughout
Pulses: +2 radial pulses, +2 pedal pulses
Incision: R thoracotomy incision clean dry intact.
No redness, no swelling, no drainage
Neurologic: AOx3, responds to questions
appropriately, movement and sensation intact
throughout.
Vital Signs:
110/54
HR 62
97% on room air
RR 15
97F

7. Labs:
WBC 11
Hgb 8.9
Hct 27.4
Plt 293
Na 130
K 4.2
Cl 99
CO2 25
BUN 26
Cr 0.8
Glu 101
Ca 7.4
Alb 2

8. Imaging
Chest CT 03/07/16
Impression:
Moderate to large right
upper lobe infiltrate with
atelectasis containing fluid
collection with air-fluid
levels, worrisome for
abscess.

9. Imaging/tests
EKG from 3/14
Ventricular Rate: 105 BPM
Atrial Rate: 113 BPM
QRS Duration: 146 ms
Q-T Interval: 358 ms
QTC Calculation(Bezet): 473 ms
R Axis: -54 degrees
T Axis: 105 degrees
Atrial fibrillation with rapid ventricular response
Non-specific intra-ventricular conduction delay
Nonspecific ST and T wave abnormality
Abnormal ECG
Echo TTE 03/10/16
CONCLUSION:
--There is no left atrial dilatation (LA volume
index 24 ml/m²).
--There is paradoxical septal motion. Other
LV walls are normal.
--LV ejection fraction is normal.
--The right ventricle has normal wall motion.
--The right atrial pressure is normal (0 - 5 mm
Hg). There is no pulmonary hypertension.
--There is no pericardial effusion. Prominent
epicardial fat pad.
--No prior study available for comparison.
3/19/16 CXR:
Findings / Impression:
Status post right thoracotomy for partial right
lung resection. Right pleural chest tube
remains. Previously described small right
apical pneumothorax is no longer discernible.
Cardiomediastinal silhouette is unremarkable
for portable technique.

10. Assessment
This is a 64 year old female with
history significant for CAD s/p
stents, HLD, HTN, TR, who is
post op day #8 s/p R upper lobe
resection of a cavitary abscess
and pneumonia, course
complicated by afib with RVR
now on PO amio, rehabilitating
well in post op unit.

11. Plan
Pulm - s/p RUL lobectomy for cavitary
mass
- ipratropium neb q4h
- albuterol 2.5 mg q4h
- Chest PT
- incentive spirometry
- OOB as tolerated
- DC chest tube when air leak
resolved
Cardiac- CAD s/p stents, HTN, HLD
- ASA 81 mg daily
- clopidogrel 75 mg daily
- lipitor 20mg po daily
- amiodarone 400mg PO twice daily
- metoprolol 12.5 mg po q12h
- heart healthy diet
- Maintain K>4 and mag>2
- Daily weights
- Trend I/Os
Neuro - post op pain, anxiety, insomnia
- cymbalta 60mg daily
- 5 mg oxycodone q4 hrs PRN for
pain

12. Plan
Renal - hyponatremia
- Trend BUN/Cr
- asymptomatic
hyponatremia, today
Na=130, continue 1000ml
daily fluid restriction
ID - cavitary lung abscess
-s/p PICC
- tygacil 50 mg IV q12 hrs
- trend WBC
- monitor temps q4h
- monitor cough and sputum
Prophylaxis:
- heparin subq 5000 units BID
- protonix 40mg daily
- Colace/senna

13. Surgery
atrial fibrillation
Prolongs hospital stay Thromboembolic events
Worse long term prognosis
$10,000 per
patient
(Onk and Erkut, 2015)

14. PICO
In post-operative cardiothoracic patients,
is amiodarone, compared to other
therapies, more effective at preventing
atrial fibrillation?

15. ● Increased atrial
pressure/atrial
enlargement
● Metabolic and electrolyte
changes
● Myocardial ischemia
● Aging
● Oxidative stress
● Hypertension
● Low EF
● ICU stress
● Pericardial inflammation
● Catecholamine release
● Systemic inflammation
● Local inflammation
Hypothesized triggers of atrial fibrillation:
● OR, interaction of all of these factors

16. Study 1:
“Is the Preoperative
Administration of Amiodarone
or Metoprolol More Effective in
Reducing Atrial Fibrillation?”
2015
Authors: Onk and Erkut
Journal: Medicine
Type of study: randomized control trial, nonblind
n= 251
Methods: 251 pre-CABG were randomly divided into 2
groups: one given metoprolol 50 mg/day vs amio
200 mg/daydaily 1 week prior to surgery and
during post-op period. Followed up 1 month
Results: AF in 14 amio patients, AF in 16 metoprolol
patients (p=0.612). No significant differences in
length of stay, cost of stay (p=0.741)
Weaknesses: only 48 hrs of tele, then daily EKG after
that. anyone with extensive cardiac history was
excluded- valve dysfunction, HF class III, prior
stents, etc
Strengths: no bradycardia, no heart block, no
discontinuation of therapy due to side effects, no
statistical differences in vessel disease, the
amount of bleeding, inotropic support, duration
to extubation, use of IABP, renal dysfunction

17. Study 2:
“Role of Atorvastatin
Administration in Protection
Against Postoperative Atrial
Fibrillation Following
Conventional CABG”
2011
Authors: Sun et al.
Journal: International Heart
Journal
Type of study: randomized control trial, single blind
placebo
n= 100
Methods: 49 given atorvastatin 20 mg daily 7 days
before surgery, 51 given placebo. The primary
endpt was occurrence of AF, CRP was measured
pre-op and q24 hrs post op until discharge.
Results: Atorvastatin significantly reduced the
incidence of postop AF (18% vs 41%, p=0.017).
and postop peak CRP level (129 vs 149 p<0.0001.)
Significantly better postop afib-free survival in
statin group. Pre op atorvastatin tx was
independently associated with significant
reduction in post op AF (p=0.007).
Weaknesses: no race mentioned, hospital stay was 13-
14 days
Strengths: ECG for 7 days post op, all operations
performed by 1 surgeon. no previous statin use,
no hx afib. No sig differences in vessel disease, hx
of infarct, HLD, HTN between groups. No GI or

18. Study 3:
“Dexamethasone for the
prevention of postoperative
atrial fibrillation” (DECS trial)
2015
Authors: Osch et al.
Journal: International Journal of
Cardiology
Type of study: randomized control trial, double blind
n= 4494 cardiac surgery pts
Methods: 2239 received single dose dex, 2255 placebo.
Patients were randomized to receive an intravenous
injection dexamethasone (1 mg/kg, with a maximum
total dose of 100 mg) or placebo, immediately after
the induction of anesthesia, but before the initiation
of CPB
Results: The incidence of any AF in the main study of 4494
patients was 33.1% in the dexamethasone and 35.2% in
the placebo group (RR 0.94, 95% CI: 0.87–1.02,
p=0.14). In the substudy of 1565 patients (more in
depth analysis), the incidence of new onset AF was
33.0% vs. 35.5% (RR 0.93, 95% CI: 0.81–1.07, p=0.31),
respectively.
Weaknesses: Visceral abdominal obesity is important
modulator of postoperative inflammation. Did not
collect baseline waist circumference as a possible
modulator of the effect of dexamethasone on AF
Strengths: high rate of follow up (loss of 4 in exp, loss of 8
in control group). The analysis of the ECGs, patient

19. Study 4:
“Ranolazine Enhances the Antiarrhythmic
Activity of Amiodarone by Accelerating
Conversion of New-Onset Atrial Fibrillation
After Cardiac Surgery”
2014
Authors: Simopoulos et al.
Journal: Coronary Heart Disease
Study year: 2014
Type of study: prospective randomized control trial,
single blind
n=41, 20 exp, 21 control
Methods: enrolled consecutive patients who
developed POAF after elective on-pump CABG,
randomized to receive either ranolazine 375 mg
twice daily orally plus intravenous amiodarone
(active group) or intravenous amiodarone alone
(control group).
Results: Time to conversion, hrs 19.9 vs 37.2 (p<.001)
Weaknesses: small sample size, but stat sig. Could be
drug independent spontaneous conversion.
Strengths: same surgeons and anesthesiologists for
each procedure. None of the patients who
received ranolazine in addition to amiodarone
showed any hemodynamic deterioration or
proarrhythmic effects during the entire treatment

20. References:
1. Onk and Erkut. (2015). Is the Preoperative Administration of Amiodarone or Metoprolol More Effective in
Reducing Atrial Fibrillation. Medicine. 94(41)
2. Sun Y1, Ji Q, Mei Y, Wang X, Feng J, Cai J, Chi L.(2011). Role of Atorvastatin Administration in Protection Against
Postoperative Atrial Fibrillation Following Conventional CABG. International Heart Journal 52(1):7-11.
3. Osch, Dieleman, van Dijk, Jacob, Luin, Doevendans, Nathoe. (2015). Dexamethasone for the prevention of
postoperative atrial fibrillation. International Journal of Cardiology 182:431-437.
4. Simopoulos, V, Tagarakis G, Daskalopoulou S, Chryssagis, K, Skoularingis, I, Molyvdas, P, Tisilimingas, N,
Aidonidis, I. (2014). Ranolazine Enhances the Antiarrhythmic Activity of Amiodarone by Accelerating Conversion
of New-Onset Atrial Fibrillation After Cardiac Surgery. Coronary Heart Disease 65(4) 294-297.