Effect of subintimal resection on initial outcome and restenosis for native coronary lesions and saphenous vein graft disease treated by directional coronary atherectomy report from the Caveat I and II investigators

Objectives. This study was designed to determine whether the depth of tissue resection affected either immediate outcome or subsequent restenosis in patients treated by directional coronary atherectomy (DCA) in the Coronary Angioplasty Versus Excisional Atherectomy Trial (Caveat) I and II studies. Background. The relation between the depth of tissue resection, immediate outcome and subsequent restenosis in lesions treated with DC has been controversial. Methods. In Caveat I, 412 patients undergoing DC had tissue samples available for analysis by the core laboratory, whereas in Caveat II, 113 patients had vein graft tissue specimens available. Results. Subintimal deep arterial wall resection was demonstrated in 169 patients (41%) in Caveat I and 40 (35%) in Caveat II. The depth of tissue resection did not affect initial procedural outcome in either Caveat I or Caveat II, nor did it affect subsequent restenosis rates at 6 months in native coronary lesions (Caveat I, 50.8% for intimal resection vs. 51.2% for subintimal resection). In patients treated with vein graft disease (Caveat II), restenosis rates varied; when resection was limited to the intima, restenosis rate of 40.4% was documented, whereas in patients with subintimal resection, the restenosis rate was 57.1%. This difference was not statistically significant (p = 0.144). Conclusions. This combined randomized series of DC for treatment of primary native coronary artery and vein graft stenoses with quantitative coronary angiography and core laboratory pathologic assessment resolves the controversy created by previous experimental and clinical dat regarding deep vessel wall resection and immediate and longer outcome. Directional atherectomy with deep arterial wall resection as practiced in these studies is safe and does not jeopardize initial success rates. More important, deep wall resection is not associated with significantly increased restenosis rates.