CARDIOVASCULAR JOURNAL OF AFRICA • Vol 23, No 7, August 2012
416
AFRICA
progression to persistent forms of AF
has been shown in a number of studies,
including a series of 350 consecutive
patients (mainly men, age 57
±
12 years)
where 75% were AF free at the end of
the first year
1
without anti-arrhythmic
drug therapy. These patients were then
followed over a five-year period. The
recurrence rate was 5.8% at two years and
25.5% at five years.
The presence of hypertension and
hyperlipidaemia was associated with
a higher risk of recurrence. From this
risk evaluation,
2
the HATCH score was
developed to help identify patients at risk
of progression from PAF to AF. Patients
with hypertension, older patients having
had a prior stroke or transient ischaemic
attack (two points), chronic obstructive
pulmonary disease and heart failure (two
points) were found to be more likely to
progress to persistent forms of AF (Table
1). ‘Catheter ablation is also superior
to anti-arrhythmic drugs and results are
nicely consistent across clinical trials’, Dr
Tilz noted.
More than one ablation procedure is
necessary to address the decline in AF
control over time. In a recently published
study,
3
which included patients with PAF,
persistent and long-standing persistent
AF, success rates after a single catheter
ablation procedure were 40, 37 and 29%
at one, two and five years, respectively,
with most recurrences during the first
six months. In all, 175 procedures were
performed in the 100 patients, with a
mean of two per patient, achieving much
higher arrhythmia-free survival of 87,
81 and 63% at one, two and five years,
respectively.
‘Using our preferred technique of
circumferential PV isolation, guided by
three-dimensional mapping and double
lasso, our centre has achieved an 80%
success rate following 1.5 procedures and
a 46% success rate after a single procedure
in a rather healthy patient population with
PAF and normal left ventricular ejection
factions’, Dr Tilz said.
‘The challenge to our team and the
electrophysiologist generally, is to achieve
permanent PV insulation over time. We
treat aggressively and early. In this way,
progression after catheter ablation is
extremely low and in this study, only four
patients (2.4%) developed chronic AF.’
Referring to recent USA data using
radiofrequency catheter (RFA) ablation
in a large cohort of older patients (mean
age 58
±
10 years), catheter ablation
limited progression to 0.6% per year
compared to 9% per year reported in
pharmacologically treated patients.
4
‘These and other studies allow us to
conclude that catheter ablation can reduce
progression to persistent AF’, Dr Tilz
said. He recommends, however, that all
patients continue with anti-coagulation
whether ablation is successful or not.
J Aalbers
1.
Shah AN, Mittal S, SIchrovsky TC, Cotiga
D,
et al
. Long-term outcome following
successful pulmonary vein isolation:
pattern and prediction of very late recur-
rence.
J Cardiovasc Electrophysiol
2008;
19
: 661–667.
2.
De Vos CB, Pisters R, Nieuwlaat R, Prins
MH, et al. Progression from Paroxysmal to
persistent atrial fibrillation clinical corre-
lates and prognosis.
J Am Coll Cardiol
2010;
55
(8): 725–731.
3.
Weersasooriya R,
et al.
Catheter ablation for
atrial fibrillation: are results maintained at 5
years of follow-up?
J Am Coll Cardiol
2011;
57
(2): 160–168.
4.
Jongnarangsin K, Suwanagool A, Chugh A,
Crawford T,
et al
. Effect of catheter ablation
on progression of paroxysmal atrial fibril-
lation.
J Cardiovasc Electrophysiol
2012;
23
(1): 9–14.
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