A Blinded, Randomized, Placebo-Controlled Trial of Percutaneous Laser Myocardial Revascularization to Improve Angina Symptoms in Patients With Severe Coronary Disease

Abstract

This study was a randomized, patient- and evaluator-blinded, placebo-controlled trial in patients treated using percutaneous myocardial laser revascularization. Previous studies using similar therapies have been confounded by placebo bias. A total of 298 patients with severe angina were randomly assigned to receive low-dose or high-dose myocardial laser channels or no laser channels, blinded as a sham procedure. The primary end point was the change in exercise duration from baseline examination to six months. The incidence of 30-day death, stroke, myocardial infarction, coronary revascularization, or left ventricular perforation occurred in two patients in the placebo, eight patients in the low-dose, and four patients in the high-dose groups (p = 0.12); 30-day myocardial infarction incidence was higher in patients receiving either low-dose or high-dose laser (nine patients) compared with placebo (no patients, p = 0.03). At six months, there were no differences in the change in exercise duration between those receiving a sham (28.0 s, n = 100), low-dose laser (33.2 s, n = 98), or high-dose laser (28.0 s, n = 98, p = 0.94) procedure. There were also no differences in the proportion of patients improving to better than Canadian Cardiovascular Society class III angina symptoms at six months. The follow-up visual summed stress single-photon-emission computed tomography scores were not significantly different from baseline in any group and were no different between groups. The modest improvement in angina symptoms assessed by the Seattle Angina Questionnaire also was not statistically different among the arms. Treatment with percutaneous myocardial laser revascularization provides no benefit beyond that of a similar sham procedure in patients blinded to their treatment status.