Patients without inducible tachyarrhythmias on electrophysiologic testing had a lower 5-year rate of cardiac arrest or arrhythmic death compared to those with inducible tachyarrhythmias (24% vs 32%; P<0.001).
RCT (n=1,750)
Randomly assigned
Does the absence of inducible sustained ventricular tachyarrhythmias during electrophysiologic testing predict a lower risk of cardiac arrest or arrhythmic death in patients with CAD, LVEF ≤40%, and asymptomatic unsustained VT?
In patients with CAD, LV dysfunction, and asymptomatic unsustained VT, the inability to induce sustained ventricular tachyarrhythmias during EP testing is associated with a significantly lower risk of sudden death or cardiac arrest.
Absolute Event Rate: 24% vs 32%
p-value: p=<0.001
BACKGROUND: The mortality rate among patients with coronary artery disease, abnormal ventricular function, and unsustained ventricular tachycardia is high. The usefulness of electrophysiologic testing for risk stratification in these patients is unclear. METHODS: We performed electrophysiologic testing in patients who had coronary artery disease, a left ventricular ejection fraction of 40 percent or less, and asymptomatic, unsustained ventricular tachycardia. Patients in whom sustained ventricular tachyarrhythmias could be induced were randomly assigned to receive either antiarrhythmic therapy guided by electrophysiologic testing or no antiarrhythmic therapy. The primary end point was cardiac arrest or death from arrhythmia. Patients without inducible tachyarrhythmias were followed in a registry. We compared the outcomes of 1397 patients in the registry with those of 353 patients with inducible tachyarrhythmias who were randomly assigned to receive no antiarrhythmic therapy in order to assess the prognostic value of electrophysiologic testing. RESULTS: Patients were followed for a median of 39 months. In a Kaplan-Meier analysis, two-year and five-year rates of cardiac arrest or death due to arrhythmia were 12 and 24 percent, respectively, among the patients in the registry, as compared with 18 and 32 percent among the patients with inducible tachyarrhythmias who were assigned to no antiarrhythmic therapy (adjusted P<0.001). Overall mortality after five years was 48 percent among the patients with inducible tachyarrhythmias, as compared with 44 percent among the patients in the registry (adjusted P=0.005). Deaths among patients without inducible tachyarrhythmias were less likely to be classified as due to arrhythmia than those among patients with inducible tachyarrhythmias (45 and 54 percent, respectively; P=0.06). CONCLUSIONS: Patients with coronary artery disease, left ventricular dysfunction, and asymptomatic, unsustained ventricular tachycardia in whom sustained ventricular tachyarrhythmias cannot be induced have a significantly lower risk of sudden death or cardiac arrest and lower overall mortality than similar patients with inducible sustained tachyarrhythmias.
Buxton et al. (Thu,) conducted a rct in Coronary artery disease with left ventricular dysfunction and unsustained ventricular tachycardia (n=1,750). Non-inducible tachyarrhythmias on electrophysiologic testing vs. Inducible tachyarrhythmias (no antiarrhythmic therapy) was evaluated on Cardiac arrest or death from arrhythmia (p=<0.001). Patients without inducible tachyarrhythmias on electrophysiologic testing had a lower 5-year rate of cardiac arrest or arrhythmic death compared to those with inducible tachyarrhythmias (24% vs 32%; P<0.001).