What burden of PVCs/NSVT in an inpatient post-MI cardiomyopathy patient would prompt an EP study-guided ICD implantation prior to discharge?

This is an interesting scenario which is best addressed by the results of the MUSTT trial. In that study patients with ischemic cardiomyopathy who had ejection fraction of </=40% and manifested NSVT (3 beats to < 30 seconds) underwent EP study and if they were inducible for sustained VT then they were randomized to ICD versus medical management. Patients randomized to ICD arm had better survival. So based on the trial, the burden of NSVT was not important. Rather, the EF was a better determinant. Also, patients included in this study were at least 4 days post MI.

There is no data to support the role of EP study for sudden cardiac death risk stratification in patients post-MI who demonstrate isolated PVCs only. For this group, however, it is important to consider the implications of high PVC burden (>10%) resulting in PVC-mediated cardiomyopathy. To prevent that, catheter ablation of PVCs can be considered.