Correspondence

Catheter Ablation in Patients with ICDs

N Engl J Med 2008; 358:2295-2296May 22, 2008

Article

To the Editor:

We strongly support the rationale for ablation of ventricular tachycardia to reduce implantable cardioverter–defibrillator (ICD) therapy, described by Reddy et al. (Dec. 27 issue),1 but would caution that risk stratification is essential to identify the subgroups of patients who would truly benefit from ablation in this setting. Ablation is time-consuming and technically challenging, with potentially significant complication rates.2 In addition, there is evidence that the clinical presentation can be used to stratify the risk associated with ICD therapy.3-5 It is therefore unfortunate that the article by Reddy et al. omits both the procedural and the clinical details that would provide readers with insight into the central questions of resource utilization and the risk–benefit ratio. Since patients with ICDs have protection against lethal ventricular arrhythmias, prophylactic substrate ablation alone would not be expected to influence mortality. Therefore, preventive ablation should be provided only in appropriate subgroups.

Prapa Kanagaratnam, Ph.D.
Michael Koa-Wing, B.Sc.
Nicholas S. Peters, M.D.
Imperial College Healthcare NHS Trust, London W2 1NY, United Kingdom
m.koawing@imperial.ac.uk

5 References

1. 1

   Reddy VY, Reynolds MR, Neuzil P, et al. Prophylactic catheter ablation for the prevention of defibrillator therapy. N Engl J Med 2007;357:2657-2665
   Full Text | Web of Science | Medline

2. 2

   Weinstock J, Wang PJ, Homoud MK, Link MS, Estes NA III. Clinical results with catheter ablation: AV junction, atrial fibrillation and ventricular tachycardia. J Interv Card Electrophysiol 2003;9:275-288
   CrossRef | Web of Science | Medline

3. 3

   Menz V, Schwartzman D, Nallamothu N, et al. Does the initial presentation of patients with implantable defibrillator influence the outcome? Pacing Clin Electrophysiol 1997;20:173-176
   CrossRef | Web of Science | Medline

4. 4

   Reiter MJ, Fain ES, Senelly KM, Robertson AD. Predictors of device activation for ventricular arrhythmias and survival in patients with implantable pacemakers/defibrillators. Pacing Clin Electrophysiol 1994;17:1487-1498
   CrossRef | Web of Science | Medline

5. 5

   Koa-Wing M, Wright I, Peters NS, Davies DW, Francis DP, Kanagaratnam P. Experience of ICD management at a UK center: cardiovascularly stable VT presentation predicts higher risk for appropriate ICD therapy. Pacing Clin Electrophysiol 2007;30:1369-1375
   CrossRef | Web of Science | Medline

To the Editor:

In the editorial accompanying the report by Reddy et al., Estes1 makes a recommendation against the use of prophylactic catheter ablation to prevent ICD therapy in patients with ischemic heart disease. Although I agree that catheter ablation should be limited to patients with recurrent ventricular arrhythmias, one should keep in mind that the only alternative in this population is treatment with antiarrhythmic drugs. However, the long-term safety of such a therapeutic strategy, which usually relies on amiodarone for its superior efficacy in preventing shocks, as compared with other agents,2 has not been established. On the contrary, a recent study showed an increase in mortality among patients with an ICD who were treated with amiodarone.3 The finding, although retrospective in nature, should not be overlooked, considering that amiodarone increases the defibrillation threshold of ICDs and may interfere with antitachycardia pacing by slowing the rate of ventricular tachycardia.4 Therefore, until data from a prospective trial become available, antiarrhythmic therapy — amiodarone in particular — should not be considered preferable to catheter ablation in patients with ICDs who have repetitive ventricular arrhythmias.

Michele Coceani, M.D.
National Research Council Institute of Clinical Physiology, 56124 Pisa, Italy
michecoc@ifc.cnr.it

4 References

1. 1

   Estes NA III. Ablation after ICD implantation -- bridging the gap between promise and practice. N Engl J Med 2007;357:2717-2719
   Full Text | Web of Science | Medline

2. 2

   Connolly SJ, Dorian P, Roberts RS, et al. Comparison of beta-blockers, amiodarone plus beta-blockers, or sotalol for prevention of shocks from implantable cardioverter defibrillators: the OPTIC Study: a randomized trial. JAMA 2006;295:165-171
   CrossRef | Web of Science | Medline

3. 3

   Worck R, Haarbo J, Thomsen PE. Electrophysiological study and `slow' ventricular tachycardia predict appropriate therapy: results from a single-centre implantable cardiac defibrillator follow-up. Europace 2007;9:1048-1053
   CrossRef | Web of Science | Medline

4. 4

   Goldschlager N, Epstein AE, Naccarelli GV, et al. A practical guide for clinicians who treat patients with amiodarone: 2007. Heart Rhythm 2007;4:1250-1259[Erratum, Heart Rhythm 2007;4:1590.]
   CrossRef | Web of Science | Medline

Citing Articles (1)

Citing Articles

1. 1

   Mishi Bhushan, Samuel J. Asirvatham. (2009) The conundrum of ventricular arrhythmia and cardiomyopathy: Which abnormality came first?. Current Heart Failure Reports 6:1, 7-13
   CrossRef