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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: mohancardio@gmail.com

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.

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