Predictive factors for early cardiac events and angiographic restenosis after coronary stent placement in small coronary arteries

OBJECTIVES The rationale of this study was to identify risk factors that predict early thrombotic events and angiographic restenosis after stenting in small coronary arteries. BACKGROUND Rates of cardiac complications and restenosis after percutaneous coronary intervention are higher in patients with small versus large coronary arteries. Because of discordant results, randomized studies comparing stent placement with balloon angioplasty could not establish the best interventional approach to use in this high-risk subset of patients. This study of predictive factors, with special focus on stent design, may provide particular help in this regard. METHODS Clinical, lesion-related, and procedural data of a large and unselected population of 3,156 consecutive patients were analyzed in a logistic regression model for both early and late complications. Repeat angiography at six months was performed in 80.8% of eligible patients. RESULTS The strongest risk factors for early thrombotic events (cumulative incidence of 4.2%) were the presence of an acute coronary syndrome and reduced left ventricular function. The stent design had no influence on early thrombotic complications. Restenosis (overall rate of 38.4%) was predominantly influenced by procedure-related variables, including the stent design and stented segment length. The incidence of restenosis varied from 29.6% to 55.8%, depending on the stent design used. CONCLUSIONS Clinical factors known before the procedure are predominant risk factors for early thrombotic complications, underscoring the need for potent antiplatelet regimens in these patients. In contrast, our findings suggest a major impact of procedural factors, including the choice of stent type, on restenosis.