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CARDIOVASCULAR JOURNAL OF AFRICA • Volume 26, No 4, July/August 2015
AFRICA
165
Prediction of mid-term outcome after cryo-balloon
ablation of atrial fibrillation using post-procedure
high-sensitivity troponin level
Tolga Aksu, Sukriye Ebru Golcuk, Tümer Erdem Guler, Kıvanç Yalin,
İ
smail Erden
Abstract
Objective:
High-sensitivity troponin I (hsTnI) assays lead to,
among other things, improvement in the detection of myocar-
dial injury and improved risk stratification of patients with
atrial fibrillation (AF). The aim of this study was to investi-
gate the association between post-procedure cardiac biomark-
ers and clinical outcome in patients undergoing cryo-balloon
ablation (CA) for AF.
Methods:
A total of 57 patients (mean age 55.1
±
12.2 years,
50.9% female) with symptomatic paroxysmal AF underwent
the CA procedure. Two hundred and twenty-eight pulmonary
veins (PVs) were attempted for pulmonary vein isolation
(PVI) with a second-generation cryo-balloon. hsTnI, CK-MB
mass and myoglobin samples were prospectively obtained
before and 24 hours after ablation.
Results:
At a mean follow up of 214.6
±
24.3 days, the prob-
ability of being arrhythmia free after a single procedure was
86%. Post-ablation hsTnI (
p
=
0.001), left atrial (LA) diam-
eter (
p
=
0.002), duration of AF (
p
=
0.002), mean minimal
temperature of the left superior pulmonary vein (
p
=
0.005),
and age (
p
=
0.021) were associated with increased AF recur-
rence rate. On multivariate analysis, lower hsTnI level was the
only independent predictor for AF recurrence (
p
=
0.012).
Post-ablation hsTnI levels lower than 4.40 ng/ml predicted
AF recurrence during follow up, with a sensitivity of 86% and
a specificity of 96%.
Conclusion:
It is well recognised that the PV antrum contrib-
utes to initiation and/or perpetuation of AF. A lower post-
ablation hsTnI level may predict an increased AF recurrence
rate, suggesting inadequate ablation of the PV antrum. This
may be used as a non-invasive marker to predict the outcome
of AF.
Keywords:
ablation, atrial fibrillation, cryo-balloon, troponin,
recurrence
Submitted 28/1/15, accepted 25/2/15
Previously published online 17/3/15
Cardiovasc J Afr
2015;
26
: 165–170
www.cvja.co.zaDOI: 10.5830/CVJA-2015-027
Atrial fibrillation (AF) is the most common cardiac arrhythmia,
with an estimated prevalence of 1–3%.
1,2
The development of
AF requires both a trigger and a susceptible substrate. The
most common trigger for AF is the myocardial sleeve of the
left atrium (LA), which extends into the pulmonary veins
(PVs).
3
However, the PV antrum also contributes to initiation
and/or perpetuation of AF.
4,5
Therefore, ablation of these
sites, particularly pulmonary vein isolation (PVI), remains the
cornerstone of AF ablation procedures.
6
However, in 25–50% of patients, PVI may not be sufficient
due to greater extension of atrial fibrosis, or PV reconnection as
a result of non-transmural lesion formation.
6-8
For this reason,
in addition to PVI, the creation of different ablation lines (roof,
posterior line and mitral isthmus) in the left atrium (LA) has
been proposed for successful radiofrequency (RF) catheter
ablation.
9-12
Application of RF energy leads to the release of myocardial
injury markers immediately after the ablation procedure and
the level of released cardiac biomarkers are linked to the extent
of ablation-induced cardiac lesions.
13
To determine the size of
effective ablation lesions comprising different energy sources,
many authors have used a variety of cardiac biomarkers.
14-25
Contrasting data exist about myocardial injury biomarker trends
after cryo-balloon ablation (CA) procedures.
15-19
In our previously published abstract, we demonstrated that
cryo-balloon ablation may be linked to significant decrease
in left atrial potentials adjacent to the PVs, particularly on
the posterior wall of the LA, compared to the RF-based PVI
procedure in patients with long-standing persistent AF, which
limited the sites of ablation.
26
To date, it is unknown whether
myocardial injury biomarkers could predict the extent of lesion
formation at long-term follow up.
We aimed to investigate the sensitivity and specificity of post-
procedural cardiac biomarker levels for predicting recurrence
of AF in patients undergoing CA for paroxysmal AF, and
to discuss the pathophysiological basis of these relationships
– inadequate left atrial ablation or unsuccessful PVI. Other
potential predictors of AF recurrence were also evaluated in the
same population.
Isolation of all PVs was the procedural endpoint. The primary
endpoints of the study were (1) comparison of peak biomarker
release in patients with/or without AF recurrence before and after
the procedure, and (2) comparison of procedural parameters in
Department of Cardiology, Derince Education and
Research Hospital, Kocaeli, Turkey
Tolga Aksu, MD,
aksutolga@gmail.comTümer Erdem Guler, MD
İ
smail Erden, MD
Department of Cardiology, Faculty of Medicine, Istanbul
University, Istanbul, Turkey
Sukriye Ebru Golcuk, MD
Kıvanç Yalin, MD