Percutaneous Laser Myocardial Revascularization - Percutaneous Laser Myocardial Revascularization
The goal of the trial was to evaluate the efficacy of percutaneous laser myocardial revascularization compared with placebo in a blinded setting among patients with severe angina.
Patients Enrolled: 298
Mean Follow Up: 6 months
Mean Patient Age: Mean age 62.9 years
Mean Ejection Fraction: Baseline mean 49.3%
Patients with a history of coronary artery disease with refractory angina (Canadian Cardiovascular Society [CCS] class III or IV), despite optimal medical therapy, and unacceptable for percutaneous or surgical revascularization procedures.
Severe left ventricular dysfunction (ejection fraction <30%), recent myocardial infarction, Braunwald class IIIb unstable angina, chronic atrial fibrillation, prosthetic valve or significant aortic valve pathology, myocardial wall thickness <9 mm, left ventricular thrombus, or major life-threatening comorbidity.
Change in exercise treadmill duration from baseline to six months.
Major adverse cardiac events (MACE) at 30 days, 6 months, and 12 months; change in CCS angina class from baseline to 6 and 12 months; change in health status and anginal symptoms baseline to 6 and 12 months; change in global and regional radionuclide perfusion scores at rest, peak stress, and redistribution using semi-quantitative and quantitative methods from baseline to 6 months; and changes in all exercise test parameters from baseline to 6 and 12 months.
Patients were randomized to treatment with low-dose (n=98) or high-dose (n=98) myocardial laser channels or no laser channels (n=102), blinded to the patient as a sham procedure. Patients underwent exercise testing at baseline, 6 months, and 12 months. The investigator was unblinded, but the patient and core laboratories were blinded to treatment group.
The majority of patients had prior myocardial infarction (67.0%) and had undergone prior coronary artery bypass surgery (88.3%). In the low-dose group, a mean of 21 laser channels were used in a mean of 1.4 treatment zones; in the high-dose group, a mean of 34 laser channels were used in a mean of 1.5 treatment zones.
In-hospital MACE occurred more frequently in the treatment groups than the placebo group (4.1% for high dose laser, 6.1% for low-dose laser, 0 for placebo, p=0.026). Likewise at 30 days, MACE occurred in 4.1% of the high dose laser group, 8.2% of the low-dose laser group, and 2.0% of the placebo group (p=0.117). The majority of the MACE events at 30 days in the laser groups were myocardial infarctions (3.1% for high dose laser, 6.1% for low dose laser, 0% for placebo, p=0.026), although there were also 2 strokes in the low dose group, one LV performation in the high dose group, and one revascularization in the high dose group. MACE events at 12 months occurred in 19.4% of the high dose laser group, 13.3% of the low-dose laser group, and 10.8% of the placebo group (p=0.223).
All three groups had improvements in exercise treadmill duration from baseline to six months, but there was no difference between groups, the primary endpoint of the trial (high dose, improved from 393.0 sec to 421.4 sec; low dose, improved from 366.0 sec to 432.2 sec; placebo, improved from 358.6 sec to 396.6 sec; p=0.348 between groups at 6 months). There was also no difference in CCS angina class at 6 months (2.0, 1.9, and 2.2 in high-dose, low-dose, and placebo groups, respectively, p=0.413), which had improved from baseline in all groups.
Among patients with severe angina, percutaneous laser myocardial revascularization was not associated with improvements in exercise treadmill duration at 6 months compared with placebo.
In addition to the lack of benefit on exercise treadmill and angina parameters, an increase in early adverse events was observed in the laser groups. The findings of lack of benefit with percutaneous laser myocardial revascularization are consistent with one other patient-blinded randomized trial by Stone GW et al but are discordant with another patient-blinded randomized trial by Salem M et al, which showed improvements in CCS angina scores with percutaneous laser myocardial revascularization. It is important to note that the present findings are applicable to only percutaneous laser myocardial revascularization and cannot be extrapolated to surgical laser myocardial revascularization. Surgical laser myocardial revascularization may allow for more precise application of the laser treatment to the needed target location, and may also allow for greater laser depth and density than percutaneous laser myocardial revascularization.
Leon MB, et al. A Blinded, Randomized, Placebo-Controlled Trial of Percutaneous Laser Myocardial Revascularization to Improve Angina Symptoms in Patients With Severe Coronary Disease. J Am Coll Cardiol 2005;46:1812-9.
Keywords: Coronary Artery Disease, Myocardial Infarction, Stroke, Myocardial Revascularization, Coronary Artery Bypass
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