Final results of the Balloon vs Optimal Atherectomy Trial (BOAT)

Abstract

Background: Previous directional coronary atherectomy (DCA) trials have shown no significant reduction in angiographic restenosis, more in-hospital complications, and higher 1-year mortality than conventional balloon angioplasty (percutaneous transluminal coronary angioplasty [PTCA]). DCA, however, has subsequently evolved toward a more "optimal" technique (larger devices, more extensive tissue removal, and routine postdilation to obtain diameter stenosis <20%).

Methods and results: The Balloon vs Optimal Atherectomy Trial (BOAT) was conducted to evaluate whether optimal DCA provides short- and long-term benefits compared with balloon angioplasty. One thousand patients with single de novo, native vessel lesions were randomized to either DCA or PTCA at 37 participating centers. Lesion success was obtained in 99% versus 97% (P=.02) of patients to a final residual diameter stenosis of 15% versus 28% (P<.0001) for DCA and PTCA, respectively, the latter including stents in 9.3% of the patients. There was no increase in major complications (death, Q-wave myocardial infarction, or emergent coronary artery bypass graft surgery [2.8% versus 3.3%]), although creatine kinase-MB >3X normal was more common with DCA (16% versus 6%; P<.0001). Angiographic restudy (in 79.6% of eligible patients at 7.2+/-2.6 [median, 6.9] months) showed a significant reduction in the prespecified primary end point of angiographic restenosis by DCA (31.4% versus 39.8%; P=.016). Clinical follow-up to 1 year showed nonsignificant 13% to 17% reductions in the DCA arm of the study for mortality rate (0.6% versus 1.6%; P=.14), target-vessel revascularization (17.1% versus 19.7%; P=.33), target-site revascularization (15.3% versus 18.3%; P=.23), and target-vessel failure (death, Q-wave myocardial infarction, or target-vessel revascularization, 21.1% versus 24.8%; P=.17).

Conclusions: Optimal DCA provides significantly higher short-term success, lower residual stenosis, and lower angiographic restenosis than conventional PTCA, despite failing to reach statistical significance for reducing late clinical events compared with PTCA with stent backup.