Intracoronary thrombus: Still a risk factor for ptca failure?

Pre‐existing intracoronary thrombus has been associated with an increased risk of percutaneous transluminal coronary angioplasty (PTCA) failure. Whether intracoronary thrombus is an independent risk factor for failure is uncertain, as conflicting data exist in the literature. Additionally, given advances in patient selection and angioplasty ballon design, it is uncertain whether the current risk posed by intracoronary thrombus is as substantial as that in the early angioplasty experience. The primary objective of this study was to first assess whether pre‐existing coronary thrombus was an independent predictor of angioplasty failure and if so, whether the risk due to thrombus had changed from the early angioplasty experience to the present time. Our prospectively collected angioplasty data base was used to identify individuals undergoing single‐vessel angioplasty of a thrombus‐containing segment from January 1, 1984 through December 1, 1991. Univariate and multivariate stepwise logistic regression techniques were utilized to analyze clinical, angiographic, and procedural characteristics associated with angioplasty failure. The study period was divided into three separate time periods and these used as variables in our multivariate analysis. In the study population that consisted of 2,699 patients with single‐vessel angioplasty, univariate analysis demonstrated that among many factors, thrombus was importantly associated with angioplasty failure (P < 0.0001). A multivariate logistic model of angioplasty failure was developed and thrombus achieved independent predictive significance in this model. Analysis with respect to time showed no variation in the importance of thrombus between our earliest angioplasty experience and that achieved in the last 2 years of the study period. Pre‐existing coronary thrombus is a risk factor for angioplasty failure which is independent of other clinical, anatomic, and procedural factors. The importance of this risk factor has not changed in our practice between 1984 and 1991.