Tachycardia: electrophysiologically guided therapy had no clear benefit.

Clinical bottom line (level 1b-)

Patients with ventricular tachyarrhythmias who were given electrophysiologically guided antiarrhythmic drug therapy, had no clear difference in sudden death than those given metoprolol, but they may be at increased risk.
Patients given electrophysiologically guided therapy had no clear difference in recurrent arrhythmia than those given metoprolol.

Steinbeck et al: The New England Journal of Medicine 1992; 327: 987-992

Expires October 2004

The study

Unblinded ?concealed randomised trial with intention-to-treat
Setting: 2 University hospitals, Germany

115 patients (aged mean 57 years, 79% male) survived electrocardiographically documented, symptomatic, sustained ventricular tachycardia (haemodynamically compromising tachycardia lasting >30 seconds); resuscitation from cardiac arrest due to documented or witnessed ventricular fibrillation; or syncope in the presence of underlying cardiac arrest, with a history of either rapid palpitations before the onset of syncope or runs of ventricular premature beats (5 or more) during long-term ECG recording, if complete noninvasive and invasive evaluations had ruled out other causes. An inducible arrhythmia (discovered with programmed stimulation) was necessary to be randomised between the 2 groups.

Excluded if

75 years or older

hypokalaemia that was the likely causes of the arrhythmia

myocardial infarction <4 weeks before the arrhythmic event

class IV heart failure as defined by the New York Heart Association

noncardiac disease with a poor prognosis

contraindications to beta-blocker therapy

had arrhythmia only during treatment with antiarrhythmic drugs or beta-blockers (suggested proarrhythmia)

declined to participate in the study after they received detailed information about it

Note:

prospective trial

Control Group: (n = 54, 54 analysed): oral metoprolol first a t a dose of 25 mg twice daily and then increased stepwise according to subjective tolerance, blood pressure and heart rate, up to 100 mg twice a day
Experimental Group: (n = 61, 61 analysed): electrophysiologically guided drug therapy based on serial testing performed with oral doses of the following agents: propafenone (450 to 900 mg daily), flecainide (200 to 400 mg daily), disopyramide (450 to 900 mg daily), sotalol (160 to 480 mg) all for at least 4 days and amiodarone 100mg daily for at least 14 days and then 400 mg daily or more).
Oral metoprolol (started at a dose of 25 mg twice daily, then increased to 50 mg twice daily) was given with propafenone, flecainide and disopyramide. Sotalol and amiodarone were administered alone. The drugs were tested in random order, but amiodarone was always tested last. The washout time between the drugs was one day.
100% followed for ? range of 18 to 48 months follow-up

The evidence

Outcome	Time to outcome	CER	EER	RRR (95% CI)	ARR (95% CI)	NNT (95% CI)
sudden death	unknown	8 (14.8%)	13 (21.3%)	-44.0% (-220% to 35.0%)	-6.50% (-20.5% to 7.48%)	-15 (NNT = 13 to infinity; NNH = 5 to infinity)
nonfatal recurrent arrhythmia	unknown	20 (37.0%)	14 (22.95%)	38.0% (-10.0% to 65.0%)	14.1% (-2.56% to 30.74%)	7 (NNT = 3.00 to infinity; NNH = 39 to infinity)

Comments

The study is too small to show any clear difference in sudden death or recurrent arrythmia between the two groups.

Citation

Steinbeck G, Andersen D, Bach P, et al: A comparison of electrophysiologically guided antiarrhythmic drug therapy with beta-blocker therapy in patients with symptomatic, sustained ventricular tachyarrhythmias. The New England Journal of Medicine 1992; 327: 987-992

Contributor: Clare Wotton and Musab Hayatli, October 1999
Reviewer:

_{Clinical Question.}

_Patient	_{ventricular tachyarrhythmias}
_{Intervention or Exposure}	_{oral metoprolol}
_Comparison	_{electrophysiologically guided antiarrhythmic drug therapy}
_Outcome	_death