The study of techniques that may improve the effectiveness of stent interventions continues to be an important area of research. One potential approach is prior debulking of the lesion using directional coronary atherectomy.

Investigators evaluated this approach in the Atherectomy before Multi-Link Improves Lumen Gain and Clinical Outcomes (AMIGO) trial. The purpose of AMIGO was to compare stenting with or without adjunctive atherectomy in native coronary arteries (de novo or restenotic). The primary endpoint was angiographic binary restenosis at 8 months.

The study included 753 patients randomized to stent plus directional coronary atherectomy or stent alone. By study design, all patients had complex lesions, including lesion length greater than 12 mm, bifurcation, ostial lesions or total occlusions. About a third of patients received abciximab (ReoPro). There were no important differences in baseline characteristics between the two groups.

Stent plus atherectomy provided better immediate angiographic results. However, at 8 weeks, the rate of binary restenosis was 19.6% in the stent only group, and 24.1% in the stent plus atherectomy group (P = 0.22). Yet the use of directional atherectomy did not increase incidence of complications in the short term or at one year.

For bifurcated lesions only, the restenosis rate was 9.8% for the combination approach, vs. 20.9% for stent only. Due to the small sample size, the finding did not reach statistical significance.

These results cast doubt on the possibility that directional atherectomy will improve lumen gain and outcome in the treatment of coronary artery lesions.

However, investigators achieved optimal directional atherectomy in only 21.5% of cases. In fact, stent plus atherectomy appeared superior to stent alone in centers that achieved an optimal result more frequently. Binary restenosis rates were significantly lower in patients who received optimal directional atherectomy vs. those who did not.

In addition, the expected rate of binary restenosis in the stent only group was 30%, as opposed to the actual 19.6% investigators reported. This lower than expected restenosis rate suggests the lesions treated may have been too favorable. Centers that treated more complex lesions had better success with stenting plus atherectomy.

Because of these factors, Dr. Colombo and colleagues still perform stenting plus directional coronary atherectomy in selected cases.