ww.sciencedirect.com
i n d i a n h e a r t j o u rn a l 6 6 ( 2 0 1 4 ) s 4 6es 4 8
Available online at w
ScienceDirect
journal homepage: www.elsevier .com/locate / ih j
Clinical Perspective
Radio frequency ablation for VT e A cost-effectivetool to combat SCD in developing countries
Mohan Nair a,*, Sanjib Kumar Patra b
aChairman e Cardiac Sciences, Saket City Hospital, Mandir Marg, Press Enclave Road, Saket,
New Delhi 110017, Indiab Senior Consultant e Cardiac Sciences, Saket City Hospital, Mandir Marg, Press Enclave Road, Saket,
New Delhi 110017, India
a r t i c l e i n f o
Article history:
Received 7 November 2013
Accepted 10 November 2013
Available online 20 December 2013
Keywords:
Radio frequency ablation
Ventricular tachycardia
Sudden cardiac death
Developing countries
* Corresponding author.E-mail address: [email protected]
0019-4832/$ e see front matter Copyright ªhttp://dx.doi.org/10.1016/j.ihj.2013.11.005
The primary focus of ventricular tachycardia (VT) manage-
ment is the assessment of subsequent risk of sudden death
and its prevention, followed by management of symptomatic
arrhythmias.
Antiarrhythmic drugs usually do not provide sufficient
protection from sudden death, but do have a role in reducing
arrhythmias that cause symptoms. Role of catheter ablation
for the management of VT comes in various clinical settings.
Some patients might not need ICDs at all. Idiopathic VT
generally has a benign prognosis and in the absence of
structural heart disease, symptomatic patients can undergo
stand-alone ablation without need for an ICD.
Catheter ablation is a reasonable first-line therapy for
many symptomatic idiopathic ventricular tachycardia.1 Pa-
tients with polymorphic VT and VF can have a triggering PVC
originating from Purkinje fibers or from the right ventricular
outflow. Perhaps those patients can have an excellent
(M. Nair).2013, Cardiological Socie
prognosis with focal catheter ablation and can be saved from
the financial burden of ICD.
It is generally recognized that ablation of VT in the setting of
structural heart disease is more difficult than ablation of idio-
pathic VT. In patients with structural heart disease, adequate
tissue ablation is often difficult to achieve due to the presence
of relatively large re-entrant circuits that they may be located
deep in themyocardium and patients havemultiple re-entrant
circuits, which further complicate the procedure.
Catheter ablation of VT in patients with arrhythmogenic
right ventricular dysplasia/cardiomyopathy was shown to be
associated with high acute procedural success and good
intermediate-term outcomes with the use of non-contact
electro anatomical mapping systems to guide the ablation.2
Better understanding of arrhythmia mechanism and demon-
stration of cardiac anatomy from use of electro anatomic
mapping systems, intracardiac echocardiography, and pre
ty of India. All rights reserved.
i n d i a n h e a r t j o u r n a l 6 6 ( 2 0 1 4 ) s 4 6es 4 8 S47
acquired MRI or CT images incorporated into mapping sys-
tems are improving ablation therapy.
Patients with a substantial risk of sudden death usually
need an ICD. ICDs effectively treat most episodes of ventric-
ular tachycardia or ventricular fibrillation and decrease mor-
tality in patients who are at high risk of sudden cardiac death
but they also have inherent risks and limitations.3 Approxi-
mately 20% of patients in primary prevention and 45% of pa-
tients in secondary prevention receive an appropriate ICD
interventionwithin the 2 years following ICD implantation.4e6
Although ICDs have been shown to improve survival when
placed for primary or secondary prevention in the presence of
structural heart disease, ICDs are not a cure for VT and do not
prevent recurrence of arrhythmias. Catheter ablation of ven-
tricular arrhythmias plays a big role in some patients with ICD
who are having recurrent shocks andmay even be curative for
some patients. Ablation can be life saving for patients with
very frequent or incessant ventricular tachycardia. Electrical
storm has been defined as three or more separate episodes of
VT within a 24 h period and has been associated with
increased mortality in patients with ICDs and may affect 4%
and 20% of the patients in the primary and secondary pre-
vention, respectively.7,8 These are usually scar-related re-
entrant ventricular tachycardias that can cause hemody-
namic collapse, which prevents extensive mapping during
ventricular tachycardia. To avoid hemodynamic compromise,
substratemapping during stable sinus rhythm is often used to
identify the area of scar and probable arrhythmia origin from
electrogram characteristics. In patients presenting with elec-
trical storm, catheter ablation may serve as the only viable
treatment option if antiarrhythmic therapy fails.
Now the question is whether catheter ablation can elimi-
nate the need for an ICD? Cost of catheter ablation is much
less than the cost of ICD and in a developing country like India,
cost-effectiveness is extremely relevant.
To date, results of two randomized prospectivemulticentre
studies have been published in patients with ischemic car-
diomyopathy and VT undergoing prophylactic catheter abla-
tion to prevent further VT.
The SMASH-VT study9 assessed the role of catheter abla-
tion in 128 patients (64 patients in each group) with previous
myocardial infarction and reduced LV ejection fraction un-
dergoing ICD implantation for secondary prevention of sud-
den cardiac death. None of the patients received Class I or III
antiarrhythmic drug therapy. The control arm underwent ICD
implantation only. Importantly, catheter ablation was per-
formed utilizing a substrate-guided approach. During an
average follow-up period of 22.5 � 5.5 months, there was a
significant decrease in appropriate ICD therapy in the ablation
group comparedwith the control arm (12 vs. 33%, p¼ 0.007). In
addition, the number of appropriate shock deliveries was
reduced and there was a trend to a reduction in the number of
patients with electrical storm. The number of patients that
needed to be treated with ablation (NNT) to avoid 1 appro-
priate ICD intervention was 5, resulting in a total of 200
appropriate ICD interventions prevented every 1000 patients
treated with catheter ablation.
The other multicentre VTACH study,10 assessed the role of
VT ablation in patients with prior myocardial infarction,
reduced EF � 50%, and haemodynamically stable VT. One
hundred and ten patients were prospectively randomized to
ICD only or VT ablation at the time of ICD implantation.
Ablation was guided by a combination of substrate mapping,
activation mapping, and pace mapping. The use of antiar-
rhythmic medication was at the discretion of the treating
physician. The median time to first recurrence of ventricular
arrhythmias was longer in the ablation group than the ICD
only group (18.6 vs. 5.9 months). There was a significantly
better rate of survival free from recurrent VT in the ablation
group (47 vs. 29%, hazard ratio ¼ 0.61, p ¼ 0.045). Upon sub-
group analysis, patients with an EF of �30% derived no benefit
from catheter ablation, while patients with an EF of >30%
demonstrated a statistically significant decrease in
arrhythmia recurrence. Some recent studies demonstrated
that a more extensive substrate ablation targeting local
abnormal ventricular activities, late potential and also
going for epicardial ablation were associated with a very
favorable outcome approaching around 85% freedom from
any VT at 2 years follow up and with a more limited use of
antiarrhythmics.11e13
Extensive endo-epicardial substrate based ablation con-
cepts targeting all the potential VT circuits within the scar can
increase the procedural success in patients with infarct-
related VT. Study involving newer ablation techniques as
first-line therapy can answer the question about the role of
ICD implantation in these patients.
Though not well established by randomized data, selected
patients with stable VT, and relatively preserved LV function
generally have a sufficiently good prognosis to undergo abla-
tion as a stand-alone therapy without placing an ICD and two
to three cases can be done with a single patch/catheter to
bring the cost further down. Patient with sustained mono-
morphic scar-related VTmay be treated with ablation early in
its clinical course. Early referral for catheter ablation following
ICD intervention has the potential to decrease arrhythmia
recurrence and ICD intervention. Available data do not allow
conclusion on the impact of primary VT ablation on mortality
and further studies are required.
The concept of prophylactic catheter ablation before ICD
implantation has special implications for countries such as
India as a) it reduces device therapy therefore increasing
quality of life and device longevity b) patientsmay require less
costly and sophisticated device and c) with increasing expe-
rience and evidence, catheter ablation has the potential for
being “stand alone” in selected patients with structural heart
disease and risk of SCD.
Conflicts of interest
All authors have none to declare.
r e f e r e n c e s
1. Kataria Vikas, Yaduvanshi Amitabh, Kumar Manoj,Nair Mohan. Demonstration of posterior fascicle tomyocardial conduction block during ablation of idiopathic left
i n d i a n h e a r t j o u rn a l 6 6 ( 2 0 1 4 ) s 4 6es 4 8S48
ventricular tachycardia: an electrophysiological predictor oflong-term success. Heart Rhythm. May 2013;10:638e645.
2. Nair Mohan, Yaduvanshi Amitabh, Kataria Vikas,Kumar Manoj. Radiofrequency catheter ablation ofventricular tachycardia in arrhythmogenic right ventriculardysplasia/cardiomyopathy using non-contactelectroanatomical mapping: single-center experience withfollow-up up to median of 30 months. J Interv CardElectrophysiol. 2011 August;31:141e147.
3. Epstein AE, DiMarco JP, Ellenbogen KA, et al. ACC/AHA/HRS2008 guidelines for device-based therapy of cardiac rhythmabnormalities: a report of the American College of Cardiology/American Heart Association Task Force on practice guidelines(Writing Committee to Revise the ACC/AHA/NASPE 2002Guideline Update for implantation of cardiac pacemakers andantiarrhythmia devices) developed in collaboration with theAmerican Association for Thoracic Surgery and Society ofThoracic Surgeons. J Am Coll Cardiol. 2008;51:e1ee62.
4. Poole JE, Johnson GW, Hellkamp AS, et al. Prognosticimportance of defibrillator shocks in patients with heartfailure. N Engl J Med. 2008;359:1009e1017.
5. Moss AJ, Greenberg H, Case RB, et al, for the MulticenterAutomatic Defibrillator Implantation Trial-II (MADIT-II)Research Group. Long-term clinical course of patients aftertermination of ventricular tachyarrhythmia by an implanteddefibrillator. Circulation. 2004;10:3760e3765.
6. A comparison of antiarrhythmic-drug therapy withimplantable defibrillators in patients resuscitated from near-fatal ventricular arrhythmias. The Antiarrhythmics versusImplantable Defibrillators (AVID) Investigators. N Engl J Med.1997;337:1576e1583.
7. Sesselberg HW, Moss AJ, McNitt S, et al, MADIT-II ResearchGroup. Ventricular arrhythmia storms in postinfarctionpatients with implantable defibrillators for primaryprevention indications: AMADIT-IIsubstudy. Heart Rhythm.2007;4:1395e1402.
8. Exner DV, Pinski SL, Wyse DG, et al, AVID Investigators:Antiarrhythmics versus implantable defibrillators. Electricalstorm presages nonsudden death: the antiarrhythmics versusimplantable defibrillators (AVID) trial. Circulation.2001;103:2066e2071.
9. Reddy VY, Reynolds MR, Neuzil P, et al. Prophylactic catheterablation for the prevention of defibrillator therapy. N Engl JMed. 2007;357:2657e2665.
10. Kuck KH, Schaumann A, Eckardt L, et al, VTACH study group.Catheter ablation of stable ventricular tachycardia beforedefibrillator implantation in patients with coronary heartdisease (VTACH): a multicentre randomised controlled trial.Lancet. 2010;375:31e40.
11. Jais P, Maury P, Khairy P, et al. Elimination of local abnormalventricular activities: a new end point for substratemodification in patients with scar-related ventriculartachycardia. Circulation. 2012;125:2184e2196.
12. Di Biase L, Santangeli P, Burkhardt DJ, et al. Endo-epicardialhomogenization of the scar versus limited substrate ablationfor the treatment of electrical storms in patients withischemic cardiomyopathy. J Am Coll Cardiol. 2012;60:132e141.
13. Vergara P, Trevisi N, Ricco A, et al. Late potentials abolition asan additional technique for reduction of arrhythmiarecurrence in scar related ventricular tachycardia ablation. JCardiovasc Electrophysiol. 2012;23:621e627.