Relation of stenosis morphology and clinical presentation to the procedural results of directional coronary atherectomy

Background. Directional coronary atherectomy has recently become available to treat coronary stenoses. This study was performed to determine the relation of patient characteristics and stenosis morphology to procedural outcome with directional coronary atherectomy to gain insight into which patients might be best treated with this device. Methods and Results. Four hundred stenoses from 378 patients consecutively treated at six major referral institutions were analyzed. Angiographic data were assessed at a central angiographic laboratory using standardized morphological criteria and computer-assisted quantitative dimensional analyses. Procedural success was achieved in 87.8% of stenoses, and major ischemic complications (death, myocardial infarction, and emergency bypass surgery) occurred in 6.3% of patients. Lesion success and complications were closely correlated with recognized modified American College of Cardiology/American Heart Association Task Force lesion morphological criteria. Observed for type A stenoses were 93% success and 3% complication rates; for type B1 stenoses, 88% success and 6% complication rates; and for type B2 stenoses, 75% success and 13% complication rates, respectively. There were too few type C stenoses treated to analyze. Furthermore, multivariate testing demonstrated stenosis angulation (multivariate p<0.001), proximal tortuosity (p<0.001), decreased preatherectomy minimum lumen dimension (p=0.032), and calcification (p=0.041) to correlate independently with adverse outcome and complex, probably thrombus-associated stenoses to have a favorable outcome (p=0.055). Operator experience (p=0.020) and a history of restenosis (p=0.022) also favorably influenced outcome. Conclusions. The procedural outcome of directional coronary atherectomy is highly associated with coronary stenosis morphology. Furthermore, after appropriate stratification for morphology and clinical presentation, overall atherectomy procedural outcome may be similar to that achieved with coronary angioplasty. However, specific subsets of patients may have relatively better outcome with either atherectomy or balloon angioplasty.