MUSTT

	Dr. Alfred Buxton discussed the Multicenter 
UnSustained Tachycardia Trial (MUSTT). This trial had
702 patients with coronary artery disease, nonsustained
ventricular tachycardia, and an EF less than 40%. The
purpose was to test whether guided anti-arrhythmic 
therapy would prolong life in a group of high-risk 
patients who had not had previous arrhythmia.
	Patients first had an electrophysiology (EP)
study to induce ventricular tachycardia. Patients who
were noninducible were entered only into a registry.
Patients who were inducible were given either 
conventional care (which did not include anti-arrhythmic
therapy) or anti-arrhythmic therapy guided by EP study.
The guided therapy required repeat EP testing with 
anti-arrhythmic drugs.
	The main result of the trial was a reduction in
arrhythmic death or cardiac arrest in patients getting
EP-guided drug therapy. In reality, the guided-therapy
patients often got an ICD when EP testing did not reveal
an effective anti-arrhythmic drug for the patient. Most
of the benefit was due to the ICD. The mortality was 
about the same in the standard care group and in the 
EP-guided drug therapy group who did not get an ICD.
	The take-away message is that the ICD appears 
to be what is driving the effectiveness of EP-guided
therapy. It is not so much that these patients have 
guided therapy, it is that they are getting an ICD.
EPS does, however, select high risk patients.
	There were many patients who were screened for
this study but did not have inducible ventricular 
tachycardia. These patients entered a registry; the 
registry patients had a better outcome than patients in
the study who got conventional therapy.