Definition of predicted effective antiarrhythmic drug therapy for ventricular tachyarrhythmias by the electrophysiologic study approach: randomized comparison of patient response criteria

Department of Medicine, Foothills Hospital and University of Calgary, Alberta, Canada.

OBJECTIVES: We sought to compare efficacies of therapy for ventricular tachyarrhythmias selected by programmed stimulation using two different patient response efficacy criteria: <5 versus <16 repetitive ventricular responses. BACKGROUND: Therapy selection for ventricular tachyarrhythmias by programmed stimulation requires definition of a patient response that predicts long-term efficacy. Such definitions have not been previously compared prospectively. METHODS: Patients with sustained ventricular tachyarrhythmias were randomized to therapy selection using either the <5 or <16 repetitive response criterion of predicted effective therapy. The primary end point was sudden death or recurrence of ventricular tachyarrhythmia requiring intervention. RESULTS: Predicted effective drug therapy was found for 23 (34%) of 68 patients randomized to the <5 criterion and 29 (36%) of 81 patients randomized to the <16 criterion (p = NS). Definition of therapy required 3.0 +/- 1.6 drug trials (mean +/- SD) in patients randomized to the <5 criterion and 2.9 +/- 1.8 trials in patients randomized to the <16 criterion (p = NS). Patients randomized to the <5 criterion had a lower 2-year probability of the primary end point (0.20 +/- 0.05) than did patients randomized to the <16 criterion (0.33 +/- 0.05, one-tailed p = 0.004). The advantage of the <5 criterion was also seen in subgroup analyses involving patients with and without an initial drug efficacy prediction. CONCLUSIONS: The programmed stimulation approach to the selection of antiarrhythmic therapy for ventricular tachyarrhythmias using a patient response criterion of <5 repetitive ventricular responses results in a lower probability of recurrence of ventricular tachyarrhythmia than does use of a <16 repetitive response criterion.

This article has been cited by other articles:

				D. G. Wyse, M. Talajic, G. E. Hafley, A. E. Buxton, L. B. Mitchell, T. K. Kus, D. L. Packer, W. H. Kou, R. Lemery, P. Santucci, et al. Antiarrhythmic drug therapy in the Multicenter UnSustained Tachycardia Trial (MUSTT): drug testing and as-treated analysis J. Am. Coll. Cardiol., August 1, 2001; 38(2): 344 - 351. [Abstract] [Full Text] [PDF]

				R. Lazzara Will Antiarrhythmic Drug Therapy Guided by Electrophysiology Study Survive in the New Millennium? Journal of Cardiovascular Pharmacology and Therapeutics, March 1, 2001; 6(1): 1 - 4. [PDF]

				S. R. Raj, L. B. Mitchell, R. S. Sheldon, B. J. Maron, W.-K. Shen, and P. Spirito Implantable Cardioverter-Defibrillators in Hypertrophic Cardiomyopathy N. Engl. J. Med., July 6, 2000; 343(1): 68 - 69. [Full Text]

				A. E. Buxton, K. L. Lee, J. D. Fisher, M. E. Josephson, E. N. Prystowsky, G. Hafley, and The Multicenter Unsustained Tachycardia Trial Inve A Randomized Study of the Prevention of Sudden Death in Patients with Coronary Artery Disease N. Engl. J. Med., December 16, 1999; 341(25): 1882 - 1890. [Abstract] [Full Text] [PDF]

				J. J. Goldberger Treatment and Prevention of Sudden Cardiac Death: Effect of Recent Clinical Trials Arch Intern Med, June 28, 1999; 159(12): 1281 - 1287. [Abstract] [Full Text] [PDF]