Intravascular Red Light Therapy after Coronary Stenting Ñ Angiographic and Clinical Follow-up Study in Humans

In animal models of coronary restenosis, intravascular red light therapy (IRLT) using a diode laser source has been shown to reduce neointimal hyperplasia following balloon-induced injury and coronary stenting. We studied the safety and efficacy of catheter-based IRLT for preventing restenosis after coronary stenting in 22 patients with angina pectoris. IRLT was performed using a diode laser (650 nm) at an energy level of 10 megawatts delivered through a rapid exchange balloon system containing the fiberoptics. The procedure was successful in all patients, with no procedural or in-hospital complications. Two patients with recurrence of symptoms had angiography at 3 and 4.1 months respectively. Angiographic follow-up was also done after 6 months in the 20 remaining asymptomatic patients. The mean minimal lumen diameter (MLD) for the whole group at 6 months follow-up was 2.57 +/- 0.62 mm. The calculated late lumen loss was 0.49 +/- 1.12 mm with a late loss index of 0.21 +/- 0.54. Four patients (2 symptomatic and 2 asymptomatic) in the series developed angiographic restenosis. Clinical events at follow-up of 10.9 +/- 3.5 months were repeat angioplasty in 2 patients for symptomatic restenosis with a 91% event free survival. These preliminary results demonstrate that IRLT after coronary artery stenting is safe and feasible; it is associated with low rates of angiographic indices of restenosis.