Commentary FGF appears to be a potent angiogenic, however there is at least a theoretical risk of potential promiscuity as it can also induce smooth muscle cell hyperplasia and fibrosis. VEGF has an advantage due to its high specificity, theoretically minimizing the concern of smooth muscle cell hyperplasia and fibrosis. The intramyocardial route was a more efficient delivery route than the intracoronary route and significantly more efficient that the intravenous route to deliver high levels of VEGF expression localized to the heart, versus systemic effects. The epicardial route was more efficacious than the endocardial route in these early studies. Protein versus gene therapy-based strategies is an area of great debate.
Gene therapy represents an alternative delivery system.
These patients appeared to demonstrate symptomatic improvement at 6-month followup. No correlation was found for a variety of risk factors, including vector or transgene delivery. In this Phase I study with a small number of patients and no placebo control, most of the patients with class 4 angina at baseline improved to class 1 by 1 month. Nitroglycerin use was reduced in most patients from about 15-27 per week to 8 or less by one month. Both effects persisted to 6 months.