CLINICAL AND ANGIOGRAPHIC OUTCOME AFTER DIRECTIONAL CORONARY ATHERECTOMY - A QUALITATIVE AND QUANTITATIVE-ANALYSIS USING CORONARY ARTERIOGRAPHY AND INTRAVASCULAR ULTRASOUND

To assess clinical and angiographic outcome after directional coronary atherectomy, the clinical course of 306 patients undergoing this proc edure was reviewed. Directional atherectomy was successful in 290 (94. 8%) procedures; complications developed in 8 (2.6%) patients. After at herectomy, percent diameter stenosis was reduced from 71 +/- 14 to 14 +/- 14% (p < 0.001) and minimal lumen diameter was increased from 0.87 +/- 0.42 to 2.55 +/- 0.57 mm (p < 0.001). In 128 (42%) patients, adju nct balloon angioplasty was performed to treat either complications or a residual stenosis > 30%. Intravascular ultrasound was also performe d in 57 patients after directional atherectomy and demonstrated that a significant amount of residual plaque mass remained in lesions with a calcium are greater-than-or-equal-to 90-degrees (17 +/- 5 mm2 vs 12 /- 5 mm2 in lesions without calcium; p = 0.007). During the 11 +/- 6 m onth follow-up period, 69 (28.3%) patients developed recurrent clinica l events (death, 5; Q wave myocardial infarction, 8; coronary bypass s urgery, 31; coronary angioplasty, 36). Using a proportional hazards mo del, independent predictors of late clinical events included diabetes mellitus (relative risk [RR] = 1.95; p < 0.05), unstable angina (RR = 2.78; p < 0.005) and a prior history of restenosis (RR = 2.21; p < 0.0 1). We conclude that directional atherectomy is associated with high p rocedural success rates and infrequent complications in selected lesio n subsets, although the degree of plaque resection may be limited if e xtensive calcium is present. Late clinical events develop in some (28% ) patients after directional atherectomy, related to certain preproced ural clinical risk factors.