Amsterdam-Rotterdam Trial - AMRO

Description:

Excimer laser vs. balloon angioplasty for coronary esions > 10mm

Hypothesis:

To compare the clinical and angiographic outcome of excimer laser angioplasty (ELCA) versus balloon angioplasty in the treatment of longer (greater than 10 mm) coronary lesions.

Study Design

Study Design:

Patients Screened: 313
Patients Enrolled: 308
Mean Patient Age: 58.8
Female: 25.6

Patient Populations:

Stable angina pectoris
Coronary lesions longer than 10mm on visual assessment
Suitable for coronary angioplasty

Exclusions:

Unstable angina
Myocardial infarction within the previous 2 weeks
Life expectancy of less than 1 year
Factors that made clinical or angiographic follow-up difficult
Intended angioplasty of a venous bypass graft
Unprotected left main disease
Extreme tortuosity of the vessel
Highly eccentric lesions
Ostial or aorta-ostial lesions
Angulated lesions of more than 45 degrees
Bifurcation lesions
Angiographic evidence of a thrombus or dissection
Total occlusions with a low likelihood of passage with a guide wire

Primary Endpoints:

Clinical: Death, myocardial infarction, coronary bypass surgery, or repeated coronary angioplasty of the randomized segment during a 6-month follow-up period. Angiographic: Minimal lumen diameter at follow-up in relation to the baseline value (net gain), as determined by an automated contour-detection algorithm.

Secondary Endpoints:

Laser success ( more than 20 percent reduction in diameter stenosis after laser angioplasty only on visual assessment)
Angiographic success (less than 50 percent residual stenosis at the end of the procedure on visual assessment)
Acute gain (treated site MLD at the end of the procedure relative to the baseline value)
Functional class at 6 months
Percent diameter stenosis at the treated coronary site at 6 months' follow-up relative to the baseline value (net gain in percentage diameter stenosis)
Restenosis rate ( more than 50 percent diameter stenosis at 6 months)
Late loss (MLD at 6 months relative to the post-procedure MLD).

Drug/Procedures Used:

Excimer laser energy (wavelength 308nm) delivered with a pulse duration of 135-210ns and a repetition rate of 20-25Hz.

Concomitant Medications:

Patients' anti-anginal medication was continued until the procedure. Nifedipine 20 mg tid was added while in hospital. Aspirin (250-500 mg qd) was given a day before the procedure and continued for 6 months afterwards.

Principal Findings:

Of the 308 patients, 151 (158 lesions) were randomly assigned to ELCA and 157 (167 lesions) were assigned to balloon angioplasty.Laser angioplasty was followed by balloon angioplasty in 98 percent of procedures. The intention-to-treat analysis yielded a laser success by visual assessment in 68 percent (107 lesions) of the 158 lesions randomly assigned to ELCA. The angiographic success rate by visual assessment was 80 percent (126 lesions) in patients treated with ELCA compared with 79 percent (132 lesions) in patients treated with balloon angioplasty.

Net mean (SD) gain in minimal lumen diameter was 0.40 (0.69) mm in patients treated with laser angioplasty and 0.48 (0.66) mm in those treated with balloon angioplasty (p=0.34).

Intimal dissections after completion of the procedure occurred in 74 lesions (46.8 percent) in the patients treated with ELCA. Most of these dissections (91 percent) were minor: type A in 27 lesions, type B in 22 lesions, and type C in 18 lesions. [15] The dissection rate was similar in patients treated with balloon angioplasty (54.5 percent [91 lesions] of patients) with 90 percent of dissections being minor: type A in 33 lesions, type B in 37 lesions, and type C in 12 lesions.

At six months, there were no deaths. Myocardial infarction, coronary bypass surgery, and repeat angioplasty occurred in 4.6 percent, 10.6 percent, and 21.2 percent, respectively, of the patients in the laser angioplasty group compared with 5.7 percent, 10.8 percent, and 18.5 percent of the balloon angioplasty group.

The restenosis rate (greater than 50 percent diameter stenosis) was 51.6 percent in the laser angioplasty group versus 41.3 percent in the balloon angioplasty group (p=0.13).

In a post-hoc analysis, 103 patients (103 lesions) with a functional or total coronary occlusion were reviewed. Of these, 49 patients were allocated to laser angioplasty and 54 patients to balloon angioplasty. The angiographic success rate was 65 percent in patients treated with excimer laser-assisted balloon angioplasty compared with 61 percent in patients treated with balloon angioplasty alone. In this subgroup, there were no significant differences between the laser and the balloon groups in the incidence of myocardial infarctions, coronary bypass surgery, repeat angioplasty, or the primary clinical end point.

Interpretation:

This first randomized clinical trial of ELCA versus balloon angioplasty in obstructive coronary artery disease demonstrated no additional benefit of ELCA with respect to the initial and long-term clinical and angiographic outcome in the treatment of obstructive coronary artery disease. It is difficult to compare the results of the present study with data from non-randomised ELCA registries. Most of these registries focused on the initial results after laser angioplasty and reported angiographic follow-up in 73-88 percent of patients after successful ELCA. In AMRO, the clinical follow-up was complete in 98 percent of patients in both groups, and angiographic follow-up was complete in over 90 percent of patients.

References:

1. Am Heart J 1993; 125: 838-47 Pilot study
2. Lancet 1996; 347: 79-84 Final results
3. Am J Cardiol 1996;78:757-762 Subgroup: Functional and total occlusions

Clinical Topics: Arrhythmias and Clinical EP, Cardiac Surgery, Invasive Cardiovascular Angiography and Intervention, Stable Ischemic Heart Disease, Atherosclerotic Disease (CAD/PAD), Aortic Surgery, Cardiac Surgery and Arrhythmias, Cardiac Surgery and SIHD, Interventions and Coronary Artery Disease, Chronic Angina

Keywords: Angioplasty, Laser, Coronary Artery Disease, Myocardial Infarction, Angioplasty, Balloon, Laser-Assisted, Angina, Stable, Intention to Treat Analysis, Constriction, Pathologic, Coronary Artery Bypass, Coronary Occlusion, Angioplasty, Balloon, Coronary, Lasers, Excimer


< Back to Listings