Definition of predicted effective antiarrhythmic drug therapy for ventricular tachyarrhythmias by the electrophysiologic study approach: randomized comparison of patient response criteria.
OBJECTIVE
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.
Mitchell
L B
LB
Department of Medicine, Foothills Hospital and University of Calgary, Alberta, Canada.
Sheldon
R S
RS
Gillis
A M
AM
Connolly
S J
SJ
Duff
H J
HJ
Gardner
M J
MJ
Hui
W K
WK
Ramadan
D
D
Wyse
D G
DG
D000206:Actuarial Analysis; D000368:Aged; D000889:Anti-Arrhythmia Agents / Q000627:therapeutic use*; D016757:Death, Sudden, Cardiac; D004558:Electric Stimulation; D004594:Electrophysiology; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D012008:Recurrence; D016019:Survival Analysis; D017180:Tachycardia, Ventricular / Q000188:drug therapy* / Q000503:physiopathology
D000889:Anti-Arrhythmia Agents