Daniel T. Walker B. App Sci
, Julie A. Humphries MBBS2
, Karen P. Phillips MBBS2
St Jude Medical, 17 Orion Rd, Lane Cove, NSW, Australia 2066,
Greenslopes Private Hospital, Newdegate St,
Greenslopes, QLD, Australia 4120.
Corresponding Author: Daniel Walker.
Patients with atrial fibrillation (AF) may be interested in undergoing concomitant interventions
on the feasibility and outcome of combined procedures in a single centre case series
Twenty-six patients underwent either first time or redo pulmonary vein isolation (PVI) procedures
by successful implant of a Watchman®
All procedures were uncomplicated with a mean case time of 233 ± 38 minutes. Maximal LAA
orifice dimension was smaller in 3 of 26 patients post PVI (range 1mm) than on the pre-procedural transoesophageal
echocardiogram (TOE). A new peri-device leak of maximum 3mm was noted in 5 of 26
patients at 6 week follow-up TOE, but resolved in 4 by the 6 month follow-up.
Combined procedures for catheter ablation for AF and Watchman® LAA implant appear to
be feasible and safe with satisfactory occlusion of the LAA maintained at follow-up.
Left atrial appendage (LAA) occlusion with the
Watchman® device (Boston Scientific, Natick,
MA, USA) has demonstrated efficacy in long
term stroke prevention for patients with nonvalvular
atrial fibrillation (AF).1
therapy for atrial fibrillation is an efficacious
rhythm control strategy for patients with symptomatic,
but its role in stroke
prevention remains unproven. Patients with
symptomatic AF may be interested in undergoing
of left atrial catheter
ablation and device occlusion of the LAA.
We report on the feasibility and outcome of com-
bined procedures in a single centre case series.
Following commercial availability and Therapeutic
of the Watchman®
left atrial appendage occlusion device
Australia in December 2009, patients with a
score of 1 or greater seeking to undergo
left atrial catheter ablation for symptomatic, drugrefractory
a single centre were
offered concomitant implant.
Patients underwent screening transoesophageal
echocardiography (TOE) and a contrast 64-slice
cardiac CT scan within 7 days of the planned
procedure. Three-dimensional reconstruction of the left atrium and pulmonary veins and LAA
was performed from the CT scan using Ensite
Verismo software (St Jude Medical, St Paul,
MN, USA) to assist with planning of the ablation
lesion set and anatomical analysis of the
LAA takeoff and morphology.4
TOE was utilised to exclude LAA thrombus
and to assess suitability of the LAA ostial dimensions
device as previously described.5
Antiarrhythmic drug therapy was ceased 3 days
prior. Therapeutic warfarin therapy was continued
uninterrupted. Dabigatran therapy was
omitted for 2 doses and recommenced 4 hours
post-procedureProcedures were performed under
general anaesthesia using a bifemoral venous approach. Intracardiac echocardiography
was utilised to guide double transeptal puncture
and during left atrial electro-anatomic 3D mapping
and during the ablation phase of the procedure.
IV heparin was administered prior to
the first transseptal puncture with a target ACT
of ≥ 350 seconds. An oesophageal thermistor
probe was positioned for monitoring of oesophageal
temperatures during the ablation phase.
Ensite NavX 3-D cardiac navigational system
(St Jude Medical, St Paul, MN, USA) with image
integration of the segmented cardiac CT scan
was utilised. A decapolar diagnostic catheter
was positioned in the coronary sinus. A 20mm
decapolar circular mapping catheter and an irrigated
tip ablation catheter were utilised for
mapping and radiofrequency ablation. Left and
right-sided pulmonary vein antral ring electrical
isolation was performed in all patients to an endpoint
or for redo ablation procedures. Patients
undergoing ablation for persistent AF were cardioverted
back to sinus rhythm following pulmonary
TOE imaging by a skilled EchoCardiologist
commenced.The more favourable transeptal sheath location was retained (typically more
posterior puncture site) and the second sheath
withdrawn to the venous circulation.Repeat TOE assessment was performed of LAA ostial dimensions
a mean LAA pressure
Post-procedure IV heparin
was reversed with Protamine and Aspirin 100mg
daily commenced.Antiarrhythmic drug therapy
was recommenced.Patients were observed overnight
in a Coronary Care Unit and generally discharged within 24 hours of the procedure.
Consecutive Persistent early tachyarrhythmias
lasting ≥ 48 hours were treated with electrical car-
dioversion. Follow-up TOE was performed at 6
weeks to reassess the Watchman® appearances,
efficacy of LAA ostial occlusion, exclude pulmonary
venous stenosis and the persistence of any
interatrial septal shunt. At 3 months if satisfactory
TOE follow-up study had been confirmed and no
further cardioversion or catheter ablation therapy
was planned then anticoagulation with warfarin
or dabigatran was discontinued and clopidogrel
therapy commenced for a further 3 months.Further
at the 6 week study.Clinical follow-up for
arrhythmia recurrence was performed at 3, 6 and 12 months guided by patient symptom reporting,
12 lead ECG and implanted cardiac rhythm device
interrogation where applicable.Holter monitoring
was performed at 12 months or as required to assess
symptom recurrence.Antiarrhythmic drug
therapy was ceased at or after 3 months according
to physician and patient discretion.
Twenty-six patients underwent combined left atrial
catheter ablation and implant of a Watchman®
LAA occlusion device between February 2010 and
June 2012. An additional 4 patients were screened
and excluded patients had LAA ostium dimensions
>31mm and proceeded with catheter abla-
tion therapy alone; 2 patients were found to have
persistent LAA thrombus despite appropriate anticoagulation
regimen of whom 1 subsequently
proceeded to open surgical excision and oversew
of the LAA.Twenty males and six females were
included with a mean age of 63 ± 7 years (range
43–73).The group included 14 patients with paroxysmal,
8 with persistent and 4 with longstanding
persistent forms of AF. The mean duration of AF
prior to the procedure was 10 ± 9 years (range 1 –
40).The mean Symptom Score for AF (CCS-SAF)6
was 3.7 ± 0.4. Twenty patients were undergoing
a first time ablation procedure for AF and 6 patients
were undergoing a redo (2nd procedure).
The mean CHADS2
score was 1.9 ± 0.7 (range 1
– 3) and mean CHADS2
VASc score was 2.6 ± 0.8
(range 1 – 4).All patients had been on established
anticoagulation prior to the procedure with 21 patients on warfarin and 5 on dabigatran.
Successful acute ablation endpoints were achieved
in all patients, including complete pulmonary
vein electrical isolation and return to stable sinus
rhythm.Successful Watchman® LAA implantation
in all patients with a small
leak of 4mm accepted in 1 patient at
implant. The mean total procedure time was 233
± 38 minutes (range 160 – 330). The mean fluoroscopic
time was 38 ± 8 minutes (range 20 – 63)
and radiation dose area product (DAP) 21 ±17
Gycm2 (range 4 – 77).There were no acute proce-dural complications. All patients were discharged
within 24 hours of the procedure.
Figure 1: CT- integrated NavX model of left atrium showing typical first-time pulmonary vein antral ring isolation ablation. Ablation lesions shown as brown dots. Panel (A) shows superior view, (B) shows left lateral view and (C) posterior view.
In patients undergoing first time ablation (ie. with an acute left pulmonary vein antral ring ablation) significant oedema of the proximal ridge or limbus between the left pulmonary veins and LAA opening was typically noted. (Fig 2.)Ostial dimensions at the planned approximate level of LAA device occlusion differed in 15 of 26 patients from the pre-procedure to post-ablation TOE.In 3 of the 15 patients the maximal LAA ostial dimension was smaller post-ablation (range 1mm), and in 12 patients the dimension was larger post-ablation (range 1 – 3mm).
Figure 2: Serial TOE images at 0° for an individual patient who underwent combined first-time ablation procedure and implant of Watchman® device. Dashed arrow shows approximate level of expected device occlusion. Panel (A) preprocedure screening; (B) post-ablation note proximal oedematous ridge (arrow) shared with left superior pulmonary vein (LSPV); (C) following deployment of Watchman® device (arrow). LAA = left atrial appendage.
All patients had satisfactory Watchman® appearances and occlusion of the LAA at 6 week followup.No device thrombus was detected.The case of peri-device leak from implant reduced from 4mm at implant to 2mm at 6weeks, then 1mm at 6 months.Five new peri-device leaks were detected at the 6 week TOE (range 1 – 3mm) with 4 of the leaks resolving again by the 6 month follow-up (Fig 3.) and one 2mm leak persisting. No pulmo-nary venous stenosis was detected.
Figure 3: Serial TOE images at 130-135° for an individual patient who developed a new peri-device leak (arrowed) at the 6 week follow-up shown in panel A, with subsequent resolution at the 6 month study as shown in Panel B. LSPV = left superior pulmonary vein.
25 of 26 patients were in sinus rhythm at 3 month follow-up and oral anticoagulation was discontinued and substituted with Aspirin/Clopidogrel in all. Twenty patients remain free of detectable arrhythmia at follow-up to date (mean 360 ± 256 days) based on symptom reporting, 12 month Holter monitor and implanted cardiac device interrogation.The mean CCS-SAF score at follow-up was 0.6 ± 0.8. Arrhythmia recurrence was noted in 6 patients (3 paroxysmal, 2 persistent, 1 longstanding persistent).Two patients subsequently underwent redo catheter ablation procedures for atrial tachyarrhythmia recurrence, (recommencingoral anticoagulation peri-procedure) with subsequent freedom from arrhythmia.Antiarrhythmic drug therapy was ceased post-procedure in 18 patients (14 paroxysmal at 3 months,4 persistent at 6 months) .No clinical neurological events were detected based on patient symptom reporting during follow-up to date (mean 360 ± 256 days). Routine neuro-radiological evaluation was not performed to examine for sub-clinical events. One patient (longstanding persistent) was deceased at 5 months post-procedure from suicide.The coronial report did not implicate the procedure in the cause or circumstances of the death.The post-mortem cardiac findings showed no cardiac thrombus, with almost complete endothelialization of the device surface.
Table 1: Demographic and Clinical Variables for Patient Group.
AF: Atrial Fibrillation, IHD: Ischaemic Heart Disease, CHF: Congestive Heart Failure, CVA: prior stroke / TIA, EF: Ejection Fraction, Echo LA area: transthoracic apical 4 chamber left atrial area ARB, angiotensin II receptor antagonist.>
To our knowledge this is the first reported experience of concomitant percutaneous left atrial appendage device closure with catheter ablation procedures for patients with atrial fibrillation. The results demonstrate the feasibility and safety of a combined procedure with either complete or satisfactory left atrial appendage occlusion maintained at follow-up.While there is the potential for ablation – induced tissue injury at the ostium of the LAA following left pulmonary vein isolation, in practice the level of occlusion with the Watchman® device is typically distal to any observed oedematous change.Variation in the maximal measured LAA ostial dimension between the preprocedure TOE and the post-ablation TOE was observed in more than half of the patients. The discrepancy, however, was most frequently an underestimation of the ostial size and is probably explained by additional fluid loading during the procedure associated with irrigated ablation, or given specifically to achieve a mean left atrial pressure ≥10 mmHg, as compared with a relatively hypovolaemic, fasted state during the screening TOE.
The development of "new" small peri-device leak at the initial follow-up TOE has also been observed by the authors in standalone Watchman® implantation (without concomitant ablation). It is presumed to be related to a minor mismatch between the circular device and typical elliptical orifice of the LAA that is partially masked by an injury / oedema response at the time of implant. Reassuringly the majority of these new leaks, although small, were observed to resolve with remodelling at subsequent follow up. Evidence suggests that small residual peri-device leaks are unlikely to compromise the efficacy of left atrial appendage occlusion devices.7
The majority of the procedures were performed on patients taking warfarin with a therapeutic INR at the time of the intervention. The safety of this approach is well documented for patients undergoing catheter ablation procedures for AF. This series suggests that this is also a safe approach for patients undergoing percutaneous LAA device occlusion.
It might be argued that left atrial appendage device occlusion would preclude subsequent access to the left atrial appendage for the ablation of focal tachycardias which may be responsible for recurrent atrial tachyarrhythmias in this population.9 The position of the Watchman® device, in contrast to other commercially available left atrial appendage device occlusion systems, is however sufficiently distal to still permit electrical isolation of the left atrial appendage ostium.
Finally, the results from catheter ablation therapy in this cohort have been comparable to outcomes for other patients at our centre, although followup times remain relatively short. The majority of patients with persistent or longstanding persistent AF, however, did not discontinue antiarrhythmic drug therapy post-procedure.
Combined procedures of catheter ablation for atrial fibrillation and percutaneous closure of the left atrial appendage with the Watchman® device were efficacious and safe in our single centre experience.
• Dr Karen Phillips has received consultancy fees from Boston Scientific.
• No financial disclosures for the other authors.
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