Heart bypass patients treated with a timed-release capsule of a substance that promotes the growth of new blood vessels showed evidence of improved blood supply and heart function, according to a study supported by the National Heart, Lung, and Blood Institute (NHLBI) of the National Institutes of Health.

"Growing" blood vessels, a strategy called angiogenesis, is a promising experimental treatment for blocked arteries in bypass surgery patients for whom surgery alone would not adequately restore blood flow to the heart.

Dr. Michael Simons and colleagues at Harvard Medical School inserted timed-release capsules of basic fibroblast growth factor (bfGF) into the heart muscle of patients scheduled for bypass surgery. Patients received either a 10 microgram (mcg) or 100 mcg dose of the substance. Other patients received a harmless placebo capsule at the time of surgery. The relatively small study (24 patients total) was designed to test the safety and effectiveness of the procedure.

The study, published in the November 2 issue of Circulation, found that there were no serious adverse effects of the treatment. Both magnetic resonance imaging (MRI) and nuclear stress testing were used to evaluate changes in blood flow. Stress tests showed a worsening of blood flow in the placebo group, no change in the 10 mcg. group and significant improvement in patients receiving 100 mcg. MRI results showed clear improvement in blood flow in patients given 100 mcg. Patients in the highest dose group were free of angina (chest pain) but some patients in the placebo and low-dose group experienced chest pain.

Simons and colleagues note that a larger (Phase II) multi-center study of this approach is currently underway.

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NIH/National Heart, Lung, and Blood Institute
1-Nov-1999