The initial clinical trials began in 1984 at St. Luke's Medical Center. A group of carefully selected patients participated in the early study. In this Phase I program, those undergoing the laser procedure also had conventional bypass surgery at the same time. The laser channels were created in an area of the heart that had severe coronary artery disease with undamaged myocardial tissue, but in an area that was not suitable for a bypass graft. The results of these early trials were promising and have been reported in the medical literature.

When a coronary artery becomes blocked, blood supply to the myocardium is reduced. This results in the pain known as angina. Prolonged or severe reduction of blood flow can damage the muscle, resulting in a heart attack.

At this time the combination procedure is appropriate when the patient is a candidate for bypass surgery but (1) there is severe disease of the small vessels, (2) there are areas of disease not suitable to place a bypass graft, or (3) in the judgment of the surgeon, the laser channels offer additional protection.