TITLE
Direct oral anticoagulants as thromboembolic prophylaxis after catheter
ablation of ventricular tachycardia: Not only safe and effective
Koichiro Ejima, MD
Department of Cardiology, Minamino cardiovascular hospital
1-25-1, Hyoue, Hachioji-shi, Tokyo, 192-0918, Japan
Corresponding author : Koichiro EjimaE-mail address :
koichiro@qf6.so-net.ne.jp
Department of Cardiology, Minamino cardiovascular hospital
1-25-1, Hyoue, Hachioji-shi, Tokyo, 192-0918, Japan
Tel : +81-42-637-8101
Conflicts of interest : none.
Word count : 841
Table : 1
Keywords: Ventricular tachycardia, anticoagulation, VT
ablation, stroke prophylaxis
Recently, warfarin has been supplanted by direct oral anticoagulants
(DOACs) for many indications. DOACs are preferred because of their ease
of use, lack of need for monitoring, and greatly reduced concern about
drug-drug interactions. However, there is clear evidence from patients
with mechanical heart valves, rheumatic valve disease, and
antiphospholipid antibody syndrome that warfarin is preferred to DOACs
because of its improved safety and/or efficacy.
After left ventricular endocardial ablation for ventricular tachycardia
(VT), especially after extensive lesions, patients are at high risk for
thromboembolism. The options for prophylactic anticoagulation therapy
are antiplatelet or anticoagulant therapy including warfarin or DOACs
(Table). However, the 2019 American College of College/Heart Rhythm
Society VT consensus document only mentions antiplatelet agents and
warfarin. 1 There are insufficient data to determine
the superiority of these drugs in terms of the safety and efficacy when
used as thromboprophylaxis after left ventricular ablation.
Siontis et al. reported the safety of warfarin and low-dose heparin
bridging for thromboembolic prophylaxis after left ventricular
ablation.2 Further, the patients enrolled in the
Thermocool VT ablation study, which was not a randomized trial, received
either warfarin (if ablation was performed in a >3-cm area)
or aspirin 325 mg, and there were no thromboembolic events in either
group.3
On the other hand, the STROKE-VT (Safety and Efficacy of Direct Oral
Anticoagulant Versus Aspirin for Reduction of Risk of Cerebrovascular
Events in Patients Undergoing Ventricular Tachycardia Ablation) trial
showed that the use of DOACs (including dabigatran, rivaroxaban, and
apixaban) was associated with a lower incidence of a postprocedural
stroke, transient ischemic attack, and asymptomatic brain magnetic
resonance imaging lesions as compared to aspirin (81
mg).4 However, no study has directly compared warfarin
and DOACs as anticoagulants after VT ablation.
In this issue of the Journal of Cardiovascular Electrophysiology,
Deshmukh et al. compare the safety and efficacy of warfarin and DOACs as
anticoagulants after VT ablation in a single-center retrospective cohort
study.5 This study included 80 consecutive patients
with structural heart disease who underwent left ventricular endocardial
ablation for VT between 2016 and 2021, including 38 consecutive patients
who received post-procedure anticoagulation with warfarin and 42
consecutive patients who received treatment with DOACs. In the warfarin
group, anticoagulation was bridged with intravenous unfractionated
heparin during hospitalization and low-molecular-weight heparin after
discharge until the therapeutic INR range (2-3) was achieved. In the
DOAC group, treatment with the DOACs was initiated as early as 6 hours
after hemostasis, provided there was no inguinal hematoma. The mean age
was 66.2 ± 11.7 years, 91% were male, 64% had ischemic cardiomyopathy,
and the mean left ventricular ejection fraction was 32 ± 14%. The
baseline characteristics were similar between the two groups. The
majority of DOACs used in this study were apixaban (88%). The majority
of the left ventricular access for mapping and ablation was via a
retrograde aortic access (91%). The duration of the radiofrequency
energy delivery (108±50 minutes vs. 113±48 minutes, p>0.05)
and procedure times (412±100 minutes vs. 472±110 minutes,
p>0.05) were similar between the patients treated with
DOACs and warfarin, and arterial closure devices were generally used
only in patients scheduled to receive DOACs after ablation. Thrombotic
events occurred one day after ablation in one patient in the DOAC group,
which was a right branch retinal artery occlusion, and one day after
ablation in one patient in the warfarin group, which were iliac deep
vein and right atrial thrombi. All bleeding complications were vascular
access-related hematomas and were comparable between the two groups
(occurred in 2 [4.8%] patients in the DOAC group and in 6
[15.8%] in the warfarin group, p=0.2). The post-ablation hospital
stay was shorter in the DOAC group than in the warfarin group (3.3±1.8
vs. 5.0±2.5 days, p=0.001).
Although this study is not a randomized trial, it is significant in that
it shows that the use of DOACs after VT ablation is as safe as a
protocol with a slowly escalating regimen of unfractionated heparin
followed by 3 months of therapeutic anticoagulation with warfarin.
Because of the rapid onset of therapeutic anticoagulation with DOACs as
compared to warfarin, there was concern that DOACs would increase
bleeding complications, but the use of vascular closure devices in the
DOAC group successfully reduced the incidence of vascular access-related
hematomas. If vascular closure devices were also used in the warfarin
group, it is likely that the incidence of vascular access-related
hematomas would have been as low as in the DOAC group.
This study also showed that anticoagulation with DOACs after catheter
ablation of ventricular tachycardia was not only as safe and effective
as warfarin for thromboembolic prophylaxis, but also resulted in shorter
length of the hospital stay after ablation than warfarin. Reduced
bleeding events and avoidance of anticoagulation titration in patients
treated with DOACs allowed for shorter hospital stays. The additional
cost associated with the use of vascular closure devices in the DOAC
group can be considered a necessary expense to reduce the length of the
hospital stay.
This new evidence for the choice of a DOAC as a means of preventing
thrombosis after VT ablation is clinically beneficial.
ORCID
Koichiro Ejima MD iD http://orcid.org/0000-0002-3195-9666
References
- Cronin EM, Bogun FM, Maury P, Peichl P, Chen M, Namboodiri N, Aguinaga
L, Leite LR, Al-Khatib SM, Anter E, Berruezo A, Callans DJ, Chung MK,
Cuculich P, d’Avila A, Deal BJ, Della Bella P, Deneke T, Dickfeld TM,
Hadid C, Haqqani HM, Kay GN, Latchamsetty R, Marchlinski F, Miller JM,
Nogami A, Patel AR, Pathak RK, Saenz Morales LC, Santangeli P, Sapp JL
Jr, Sarkozy A, Soejima K, Stevenson WG, Tedrow UB, Tzou WS, Varma N,
Zeppenfeld K. 2019 HRS/EHRA/APHRS/LAHRS expert consensus statement on
catheter ablation of ventricular arrhythmias. Heart Rhythm
2020;17:e2-e154.
- Siontis KC, Jamé S, Sharaf Dabbagh G, Latchamsetty R, Jongnarangsin K,
Morady F, Bogun FM. Thromboembolic prophylaxis protocol with warfarin
after radiofrequency catheter ablation of infarct-related ventricular
tachycardia. J Cardiovasc Electrophysiol 2018;29:584–590.
- Stevenson WG, Wilber DJ, Natale A, Jackman WM, Marchlinski FE, Talbert
T, Gonzalez MD, Worley SJ, Daoud EG, Hwang C, Schuger C, Bump TE,
Jazayeri M, Tomassoni GF, Kopelman HA, Soejima K, Nakagawa H;
Multicenter Thermocool VT Ablation Trial Investigators. Irrigated
radiofrequency catheter ablation guided by electroanatomic mapping for
recurrent ventricular tachycardia after myocardial infarction: the
multicenter thermocool ventricular tachycardia ablation trial.
Circulation 2008;118:2773-2782.
- Lakkireddy D, Shenthar J, Garg J, Padmanabhan D, Gopinathannair R, Di
Biase L, Romero J, Mohanty S, Burkhardt DJ, Al-Ahmad A, Atkins D,
Bommana S, Natale A. Safety/Efficacy of DOAC Versus Aspirin for
Reduction of Risk of Cerebrovascular Events Following VT Ablation.
JACC Clin Electrophysiol 2021;7:1493-1501.
- Deshmukh A, Gunda S, Ghannam M, Liang J, Latchamsetty R, Jongnarangsin
K, Morady F, Bogun F. Comparison of Warfarin with Direct Oral
Anticoagulants for Thromboembolic Prophylaxis after Catheter Ablation
of Ventricular Tachycardia. J Cardiovasc Electrophysiol 2023 Jan 19.
doi: 10.1111/jce.15827. Epub ahead of print. PMID: 36655538.