Elsevier

Heart Rhythm

Volume 11, Issue 4, April 2014, Pages 549-556
Heart Rhythm

Pulmonary vein isolation: The impact of pulmonary venous anatomy on long-term outcome of catheter ablation for paroxysmal atrial fibrillation,☆☆

https://doi.org/10.1016/j.hrthm.2013.12.025Get rights and content

Background

Circumferential pulmonary vein (PV) isolation is the cornerstone of catheter ablation for atrial fibrillation (AF); however, PV reconnection remains problematic.

Objective

To assess the impact of PV anatomy on outcome after AF ablation.

Methods

One hundred two patients with paroxysmal AF underwent cardiac magnetic resonance (60%) or computed tomography (40%) before AF ablation. PV anatomy was classified according to the presence of common PVs, accessory PVs, PV branching pattern, and the dimensions of the PV ostia, intervenous ridges (IVRs), and the left PV-left atrial appendage ridge.

Results

Four discrete PVs were present in 48(47%) of the patients: a left common PV in 38(37%), a right common PV in 2(2%), an accessory right PV in 20(20%), and left PV in 4(4%). At a mean follow-up of 12 ± 4 months, 75 of 102 (74%) patients were free of recurrent AF. A LCPV was associated with an increase in freedom from AF (87% vs 66% for 4 PV anatomy; P = .03). Greater left IVR length (16.9 ± 3.5 mm vs 14.0 ± 3.0 mm; P ≤ .001) and width (1.4 ± 0.6 mm vs 1.1 ± 0.6 mm; P = .02) were associated with increased AF recurrence. After multivariate analysis, abnormal anatomy (LCPV or accessory PV) and left IVR length were found to be the only independent predictors of freedom from AF.

Conclusions

Four discrete PVs are present in the minority of patients with paroxysmal AF undergoing PV isolation. The presence of a LCPV is associated with an increased freedom from AF after catheter ablation. PV anatomy may in part explain the variable outcome to electrical isolation in patients with paroxysmal AF.

Introduction

Circumferential pulmonary antral ablation is a commonly used technique to achieve pulmonary vein isolation (PVI) in patients with atrial fibrillation (AF). However, PVI is limited by AF recurrence in up to 30% of the patients with paroxysmal AF.1 Despite advances in catheter-based technology and operator experience, pulmonary vein (PV) reconnection continues to thwart the success of catheter ablation.

Pulmonary venous anatomy demonstrates considerable inter- and intraindividual variation with common PVs, accessory PVs, and significant difference in the dimensions of the intervenous ridge and PV-appendage ridge. With advances in catheter contact technology, we have gained new insights into the challenges of tissue contact at these locations that may in part translate to the variable outcomes after PVI. The intervenous ridge (IVR) and the left PV-left atrial appendage (LAA) ridge are preferential sites of not only acute PV isolation but also chronic PV reconnection.2, 3 Interestingly, adequate catheter contact is difficult to achieve in these locations4, 5 and may translate to sites of PV reconnection at the time of repeat procedure for recurrent AF.4

Prior studies have explored the impact of pulmonary venous anatomy on the outcomes of catheter ablation with conflicting results. Pulmonary venous anatomy demonstrates considerable diversity with a left common pulmonary vein (LCPV) present in 9%–83% of the patients and accessory PVs in 17%–29% of the patients undergoing catheter ablation.6, 7 Right-sided accessory PVs have been associated with improved success after PVI,8 though other series did not demonstrate an association between atrial anatomy and procedural outcomes.9, 10

We conducted a prospective study to determine the impact of pulmonary venous anatomy on outcome after catheter ablation for paroxysmal AF.

Section snippets

Study population

Patients with highly symptomatic paroxysmal AF resistant to at least 1 antiarrhythmic drug (AAD) were prospectively recruited before first time PVI between January 2010 and January 2012. Patients underwent preprocedural cardiac magnetic resonance (CMR) imaging or computed tomography (CT) for the assessment of LA anatomy. AF was classified as paroxysmal if episodes were self-terminating within 7 days or cardioverted within 48 hours of onset. Patients were required to have normal renal function

Baseline characteristics and procedural outcomes

One hundred two patients with paroxysmal AF (mean age 59 ± 9 years; 67% men) underwent CMR or CT before AF ablation (MRI in 60% and CT in 40%). Segmentation of the left atriogram for LA anatomy was performed with NavX in 85% and with CARTO 3 in 15%. Acute procedural success, defined as PVI, was achieved in all patients. At a mean follow-up of 12 ± 4 months, 75 of 102 (74%) patients were in sinus rhythm off AAD after a single procedure (Table 1).

Common or accessory PVs

Four discrete PVs were identified in 47% of the

Discussion

Atrial and PV anatomy demonstrates considerable variation between patients. 3D mapping with image integration has improved our appreciation of the anatomic diversity and assisted our ability to complete PVI despite often challenging terrain. In the present study, we demonstrated that pulmonary venous anatomy is an important determinant of outcome in patients undergoing PVI for paroxysmal AF. The main findings were as follows:

  • 1.

    typical 4-PV anatomy is present in 47% of the patients, with a LCPV in

Conclusions

Four discrete PVs are present in the minority of patients with paroxysmal AF undergoing PVI. The presence of a LCPV is associated with an increased freedom from AF after catheter ablation. PV anatomy may in part explain the variable outcome to electrical isolation in patients with paroxysmal AF.

References (22)

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    Atrial fibrillation: multi-detector row CT of pulmonary vein anatomy prior to radiofrequency catheter ablation—initial experience

    Radiology

    (2005)
  • Cited by (72)

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      Whereby, it is important to emphasize three points: the lower prevalence of a LCO in this study (16%) compared with other studies, persistent AF was present in 45% of patients and these patients received an ablation strategy extending beyond PVI, which may explain the results obtained [9]. McLellan et al. assessed 102 patients and found that 37% presented LCO and had a success rate in the clinical follow-up of 87% compared with 66% in patients with two left PVs, after application of Cox regression multivariate models (p = 0.03) [6]. Sohn et al. assessed the influence of PV anatomy in patients undergoing RF ablation with remote magnetic navigation and found that the rates of recurrence were 32% in patients with normal PV anatomy, 41% in patients with a LCO, and 25% in patients with a RCO.

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    This research was supported in part by the Victorian Government’s Operational Infrastructure Funding.

    ☆☆

    Dr McLellan is supported by a co-funded Australian National Health and Medical Research Council (NHMRC)/Australian National Heart Foundation (NHF) Postgraduate Scholarship. Dr Ling is supported by an NHF Postgraduate Scholarship. Dr Wong is the recipient of the Keith Goldsbury Postgraduate Research Scholarship Award (award no. PC11M 6218) from the National Heart Foundation of Australia. Dr Walters is supported by an NHMRC Postgraduate Research Scholarship. Dr Taylor is supported by an NHMRC project grant. Dr Kistler is supported by a practitioner fellowship from the NHMRC.

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