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. Author manuscript; available in PMC: 2011 Dec 26.
Published in final edited form as: Thromb Res. 2010 Jan 6;126(2):e69–e77. doi: 10.1016/j.thromres.2009.11.031

Table 1.

Clinical Trials Evaluating Peri-Procedural Anticoagulation for Atrial Fibrillation Ablation.

Authors Patients Pre-Procedural AC Intra-
Procedural
AC		 Post-Procedural AC Bleeding Stroke/TIA
Schmidt, et al 2009 [33] n = 194


Follow-up:		 Warfarin or phenprocoumon
either continued pre-
procedure or started 3 days
prior to procedure

Controls (n = 107): INR
<2 day of procedure

Cases (n = 87): INR ≥2 day
of procedure
Procedure postponed if INR
>3.5 day of procedure		 ACT 350–450 Controls: enoxaparin 0.5
mg/kg BID started 6–8
hours post-procedure
and continued until
therapeutic INR achieved
Warfarin or phenprocoumon
restarted in all patients
PM of procedure		 Minor vascular
complicationsa
Controls: n = 7 (6.5%)
Cases: n = 5 (5.8%)
p = NS
Major vascular
complicationsb:

Controls: n = 1 (0.93%)
Cases: n = 1 (1.2%)		 Controls: n = 0

Cases: n = 1 (1.2%)
Bunch, et al 2009 [41] n = 630


CHADS2 score
0–1: 20%
CHADS2 score
≥2: 80%
Mean follow-up:
327 ± 368 days		 NR NR UFH 4 hours post-sheath
removal and continuing
for 24 hours
If CHADS2 score
0–1 = ASA 325 mg daily
(n = 123)

If CHADS2 score 2: LMWH
(dose NR) + warfarin
(n = 507)		 NR ASA group = 0%


Warfarin group = 0.4%

p = NS
Prudente, et al 2009 [31] n = 539
(603 procedures)
Mean follow-up:
1 month		 Warfarin D/C 4 days pre-
procedure to achieve
INR <2		 ACT 300–350 Warfarin re-started 4–6
hours post-procedure
enoxaparin 1 mg/kg at
4 hours post-procedure
and the next AM
Protocol A (n = 263):
enoxaparin 1 mg/kg BID
× 5 additional days
Protocol B (n = 85):

enoxaparin 1 mg/kg BID
× 3 additional days
Protocol C (n = 255):
enoxaparin 0.5 mg/kg BID
× 3 additional days		 Femoral vascular
complications:
Protocol A: 5.7%


Protocol B: 2.4%
Protocol C: 1.6%
p<0.03
(comparing A to B + C
or A to C)		 Protocol A: n = 1 (0.38%)

Protocol B: n = 0


Protocol C: n = 0
Scherr, et al 2009 [10] n = 579
(721 procedures)

CHADS2 score 0–1:
580/721 (79)%
CHADS2 score ≥2:
152/721 (21%)
Follow-up: 3
months		 Warfarin (INR 2–3) for at
least 4 weeks pre-ablation



Warfarin D/C 5 days pre-
procedure, and bridged
with enoxaparin
0.5–1 mg/kg BIDg 		ACT 300–400 Warfarin + UFH initiated
6 hours post-sheath
removal
UFH D/C and enoxaparin
0.5–1 mg/kg BIDc started
the following AM and
continued until INR >2
Warfarin continued for at
least 3 months		 Pericardial effusions
n = 9/721 (1.2%)

Femoral vascular
complications
n = 11/721
(1.5%)		 Within ≤30 days post-
procedure: n = 10/721
(1.4%) (9 were within 24
hours of procedure, 1
within 6 days of procedure)


CHADS2 score 0: 0.3%

CHADS2 score 1: 1.0%
CHADS2 score ≥2: 4.7%
Mortada, et al 2008 [28] n = 207

CHADS2 score 0–1:
88%
CHADS2 score ≥2:
12%

Mean follow-up:
24 ± 6 months		 Warfarin D/C 3 days pre-
procedure, then ASA
325 mg daily × 3 days

Need
INR ≤2		 ACT 300–350 Warfarin (INR 2–3) and
ASA restarted day of
procedure and continued
for 6 weeks
Warfarin continued beyond
6 weeks only if pt had AF
recurrence or prior history
of persistent AF

If no AF recurrence at 6
months, warfarin D/C
ASA continued for at least
6 months in all patients		 Groin hematoma
n = 2 (0.97%)
Pericardial effusion
n = 2 (0.97%)		 n = 2 (0.97%)

CHADS2 scores 1, 2

Both events occurred within
8 days of procedure, both
with subtherapeutic INR
Rossillo, et al 2008 [47] n = 170

n = 85 undergoing
PVAI
(28% low-medium
stroke riskf; 72%
high stroke riskf)
n = 85 matched
controls
undergoing DCCV
(24% low-medium
stroke riskf; 76%
high stroke riskf)
Mean follow-up:
15 ± 7 months		 AC started 1 month
pre- procedure		 ACT 350–400 ASA 325 mg × 1 dose given
at the end of procedure
All patients discharged
with warfarin × 3 months
Warfarin was D/C after
3 months unless patient
had one of the following:
recurrence of AF >60% PV
narrowing Poor atrial
contractility Presence of
other indications for AC		 NR PVAI group n = 1 (1.2%)
(<30 days after procedure)
Control group

n = 5 (5.9%)


(1 <30 days after procedure,
4>30 days after procedure)
Nademanee, et al 2008 [29] n = 635 (1,065
procedures)


Age>65 or had
at least 1 stroke
risk factor
Mean follow-up:
836 ± 605 days		 Warfarin (INR 2–3) for
at least 3 weeks pre-
procedure




Warfarin D/C 4 days
pre-procedure


If persistent or permanent
AF, bridged with
enoxaparin 1 mg/kg BID		 NR Warfarin + enoxaparin 1
mg/kg BID restarted
immediately
post-procedure
Enoxaparin D/C 3 days
later

Warfarin D/C after 3
months if NSR maintained,
then ASA or clopidogrel
prescribed		 Hemopericardium
n = 9/635 (1.4%)


Femoral vascular
complications
n = 13/635 (2%)		 n = 11/517 (2.1%)



Patients who D/C warfarin
n = 5/434 (1.2%)

Patients who
continued warfarin
n = 6/83 (7.2%)

4 with adequate INRs 3
months prior, 2 had no
documented INR within
3 months of event
Seow, et al 2007 [32] n = 56 (86
procedures)



Mean follow-up:
21.6 ± 8.8 months		 AC D/C 3–5 days pre-
procedure		 ACT 300–350 UFH 4 hours post-
procedure and continued
until the following AM,
then changed to LMWH
until INR >2
Warfarin re-started the
following AM		 Cardiac tamponade
n = 1 (1.1%)		 n = 2 (2.3%)
Wazni, et al 2007 [27] n = 355

Mean follow-up:
3–4 months		 Groups 1 and 2: warfarin D/C
2–3 days prior to procedure








Group 3: warfarin continued
without interruption
(INR 2–3.5)		 ACT 350–450 ASA 325 mg × 1 dose at
the end of procedure



Warfarin restarted PM of
procedure


Group 1 (n = 105):


enoxaparin 1 mg/kg BID
until INR >2


Group 2 (n = 100):
enoxaparin 0.5 mg/kg BID
until INR >2
Group 3 (n = 150):
continued warfarin
(INR 2–3.5)		 Minor bleedingd:

Group 1: n = 23 (22%)

Group 2: n = 19 (19%)
Group 3: n = 8 (5.3%)

p<0.001

Major bleedinge:


Group 1: n = 9
((8.6%)
Group 2: n = 0 (0%)
Group 3: n = 0 (0%)
p<0.001		 Group 1: n = 1 (0.95%)



Group 2: n = 2 (2%)


Group 3: n = 0
p = NS
Oral, et al 2006 [30] n = 755

No stroke risk
factorsc: 44%
≥1 stroke risk
factorsc: 56%
Mean follow-up:
25 ± 8 months		 Warfarin D/C 5 days pre-
procedure		 ACT 300–350 UFH 1000 units/hour
within 3 hours of sheath
removal, continued until
the following AM, then
changed to enoxaparin
0.5 mg/kg BID until INR ≥2
Warfarin restarted PM of
procedure and continued
for at least 3 months
ASA 81–325 mg daily
indefinitely after warfarin
D/C		 Cerebral hemorrhage
n = 2 (0.3%)		 ≤30 days of ablation:
n = 7 (0.9%)
(1 intraprocedural, 3 on
enoxaparin with INR <2,


3 off enoxaparin with
INR ≤2)

>30 days post-ablation:
n = 2 (0.3%)
(both on warfarin with
INR 2.6–3.2)
Wazni, et al 2005 [11] n = 785

Follow-up:
12 months		 Warfarin (INR 2–3)

D/C 48 hours pre-
procedure		 Group 1:
(n = 194)
ACT 250–300		 ASA × 1 dose at end of
procedure (dose NR)



Warfarin restarted day
of procedure		 Groin hematoma:

Group 1: n = 1

Group 2: n = 2
Group 3: n = 2		 Group 1: n = 7 (3.6%)




Group 2: n = 3 (1.7%)
Wazni, et al 2005 [11] Group 2:
(n = 180)
ACT 300–350 +
Eptifibatide

Group 3:
(n = 411)
ACT 350–400		 If history of persistent
AF: enoxaparin 0.5 mg/kg
BID until therapeutic INR
achieved

Warfarin D/C after 4–6
months unless
AF recurrence or >70% PV
narrowing		 Pericardial effusion:

Group 1: n = 1
Group 2: n = 1
Group 3: n = 0
Cardiac tamponade:

Group 1: n = 1

Group 2: n = 1
Group 3: n = 0

Group 3: n = 2 (0.49%)


All events were intra-
procedural

AC = anticoagulation; ACT = activated clotting time; AF = atrial fibrillation; AM = morning; ASA = aspirin; BID = twice daily; CHADS2 = stroke risk stratification system; D/C = discontinued; DCCV = direct current cardioversion; INR = international normalized ratio; LMWH = low-molecular weight heparin; NR = not reported; NSR = normal sinus rhythm; PM = evening; PV = pulmonary vein; PVAI = pulmonary vein antrum isolation; TIA = transient ischemic attack; UFH = unfractionated heparin.

a

minor vascular complications defined as hematoma that did not require intervention;

b

major vascular complications defined as hematoma that required intervention or bleeding that required blood product transfusions;

c

congestive heart failure, hypertension, age >65, diabetes mellitus, prior stroke or transient ischemic attack;

d

hematoma not requiring intervention;

e

cardiac tamponade, hematoma requiring intervention, bleeding requiring transfusion;

f

low stroke risk defined as age <65, no hypertension, no diabetes, no congestive heart failure, no previous stroke; medium stroke risk defined as age >65, no hypertension, no diabetes, no congestive heart failure, no previous stroke; high stroke risk defined as age >65 plus hypertension or diabetes or congestive heart failure or previous stroke OR age >75 without other risk factors;

g

enoxaparin 1 mg/kg BID used from 2001–2004, but then was decreased to 0.5 mg/kg BID from 2005–2008 due to high incidence of vascular complications.