Ventricular Tachycardia Ablation versus Escalation of Antiarrhythmic Drugs

Christian Deaton, Mercer University College of Pharmacy

Ventricular tachycardia caused by the scarring that occurs after myocardial infarction (MI) carries a substantial risk of death, a risk that is reduced by the placement of an implantable cardioverter–defibrillator (ICD). [1]

It is suggested that ICDs terminate ventricular tachycardia, but recurrent arrhythmias and ICD shocks may cause impairment in a patient’s quality of life.  If ventricular tachycardia recurs despite anti-arrhythmic drug (AAD) therapy, catheter ablation or an escalation in drug therapy is recommended as an alternative. [2]

Ventricular Tachycardia Ablation versus Escalation of Antiarrhythmic Drugs  [3]
Design Multi-center, randomized, controlled trial; N= 259
Objective To compare catheter ablation with escalated anti-arrhythmic drug (AAD) therapy in patients with ischemic cardiomyopathy and an implantable cardioverter–defibrillator (ICD) who had ventricular tachycardia despite AAD therapy
Study Groups Catheter ablation; n= 132

Anti-arrhythmic drug therapy; n= 127

Methods Patients were randomly assigned to receive either catheter ablation (ablation group) with continuation of baseline anti-arrhythmic medications or escalated anti-arrhythmic drug therapy (escalated-therapy group). In the escalated therapy group, amiodarone was initiated if another agent had been used previously. The dose of amiodarone was increased if it had been less than 300 mg per day or mexiletine was added if the dose was already at least 300 mg per day.
Duration July 2009 through November 2015
Primary Outcome Measure Composite of death, three or more documented episodes of ventricular tachycardia within 24 hours (ventricular tachycardia storm), or appropriate ICD shock
Baseline Characteristics
  Esclated therapy; n= 127 Catheter ablation; n= 132
Age, average 70.3 67
Male, n 118 123
Previous percutaneous coronary intervention (PCI), n 62 50
Diabetes, n 40 37
Years since last myocardial infarction, average 15.7 15.7
Hypertension, n 88 92
Atrial fibrillation or flutter, n 47 52
Results The primary outcome occurred in 78 of 132 patients (59.1%) in the ablation group, and in 87 of 127 patients (68.5%) in the escalated-therapy group.
Adverse Events Common Adverse Events: hepatic dysfunction (5%)
Serious Adverse Events: Death via pulmonary toxicity (27%)
Percentage that Discontinued due to Adverse Events: (7%)
Study Author Conclusions Among patients with ischemic cardiomyopathy who had recurrent ventricular tachycardia and an ICD despite first-line AAD therapy, the rate of the composite outcome of death at any time or ventricular tachycardia storm or appropriate ICD shock after 30 days was lower in the catheter ablation group versus patients who received escalated AAD therapy.

 

The study revealed that the use of catheter ablation therapy resulted in fewer deaths, episodes of ventricular tachycardia within 24 hours,  or appropriate episodes of ICD shock when compared to escalated AAD therapy in the specific patient population.  Limitations of the study included the patient population that was studied.  The study consisted of patients who had a high disease burden relatively late in the course of advanced cardiac disease and evaluated second-line therapy for ventricular tachycardia.  Thus, further study would be required to show whether catheter ablation or AAD therapy is the most effective first-line therapy for scar-related ventricular tachycardia.

 

References

  1. The Antiarrhythmics versus Implantable Defibrillators (AVID) Investigators. A review of antiarrhythmic-drug therapy with implantable defibrillators in patients resuscitated from near-fatal ventricular arrhythmias. N Engl J Med 1997; 337:1576-83.
  2. Dunbar SB, Dougherty CM, Sears SF, et al. Educational and psychological interventions to improve outcomes for recipients of implantable cardioverter defibrillators and their families: a scientific statement from the American Heart Association. Circulation 2012;126:2146-72.
  3. Sapp JL, Wells GA, Parkash R, et al. Ventricular Tachycardia Ablation versus Escalation of Antiarrhythmic Drugs. N Engl J Med. 2016;375(2):111-21.
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