720-4 Coronary Dissection Following Rotational Atherectomy: Clinical Characteristics, Angiographic Predictors and Acute Outcomes

Rotational atherectomy (RA) employs a novel methodology to debulk coronary lesions. Ratherthan improving lumen dimension by stretching and splitting the artery as with balloon angioplasty (PTCA), RA differentially abrades the less compliant atherosclerotic lesion. The effect of this unique mechanism on the incidence and outcome of coronary dissection is unknown. We analyzed 2293 lesions from the Heart Technology Multi-Center Registry treated with RA to determine predictive factors for and outcomes following coronary dissections. The incidence of dissection was 8%. Of the dissected vessels, 22% showed evidence of persistent dye staining. There were no differences in age (mean, 63yr) and gender (70% male) between the dissection and non-dissection groups. The incidence of hypertension, diabetes, hypercholesterolemia and smoking was not increased in patients with dissections. The frequency of prior MI, prior CABG and unstable symptoms was not greater in patients with dissection. Patients with dissections were more likely to have calcified lesions (57% vs 49%; p=0.01), tortuous vessels (36% vs 23%; P<0.001), AHA/ACC type C lesions (29% vs 18%; p=0.0001) and primary (79% vs 67%: p<0.001) rather than restenotic lesions compared to patients without dissection. Maximal burr size did not differ between the dissection and non-dissection groups. Following dissection, 15% of vessels had sub-TIMI III flow. Adjunctive PTCA increased the TIMIIiI flow rate to 94%. The occurrence of dissection was associated with a greater residual stenosis following RA when compared to vessels without dissection (43% vs 38%) but that difference was negated following adjunctive PTCA (23% vs 20%). Nevertheless, the procedural success rate «50% residual stenosis without major complications) was reduced in the presence of dissection (86% vs 96%; p<0.001) primarily because patients with dissection more frequently required CABG than those without dissection (6.4% vs 1.9%; P<0.001). The incidence of in-laboratory closure, out-of-Iaboratory closure, coronary pelioration, Q-wave MI, non-Q MI and death were not increased in patients with dissection.ConclusionCoronary dissection is an uncommon complication of RA that shares many predictors with PTCA but may have a more benign outcome