This prospective, double-blind, randomized, sham-controlled
trial was designed to control for patient and
investigator bias in assessing symptomatic improvement
after percutaneous myocardial laser revascularization
(PMLR) therapy. Eighty-two patients with stable angina
pectoris (class III or IV) not amenable to conventional
revascularization and with evidence of reversible ischemia,
ejection fraction >25%, and myocardial wall
thickness >8 mm were randomized to either PMLR with
optimal medical therapy (n
40) or to a sham procedure
with optimal medical therapy (n
42). With the
exception of 1 laser technician, all patients, investigators,
and assessors were blinded to treatment through
the 12-month follow-up. The primary end point was
restricted to Canadian Cardiovascular Society angina
class improvement to limit the number of patients exposed
to a sham procedure. Secondary assessments
included medication usage, quality of life, exercise testing,
ejection fraction, and hospitalizations. The incidence
of serious adverse events, as determined by cardiac
event-free survival at 12 months, was similar between
groups. At 12 months, Canadian Cardiovascular Society
angina scores improved by >2 classes in significantly
more PMLR-treated patients than sham control patients
(35% vs 14%, p
0.04). Angina-specific quality-of-life
measures were significantly higher in the PMLR group at
each follow-up (p