The Role of Coronary Arteriography in Demonstration of Mural Thrombosis after Angioplasty (12)

Despite significant advances in intravascular imaging techniques, contrast arteriography is likely to retain its unique value for exploration of the entire anatomy of the vascular tree. Better knowledge of the limitations and capabilities of this method will clarify the specific indications for novel techniques, such as angioscopy and ultrasound, which improve anatomic definition of individual lesions.
In particular, recognition of intracoronary thrombi after angioplasty may prove to be clinically relevant, at least for large thrombi. First, thrombosis underlies most of the acute complications of angioplasty. Although such complications occur at a rate of about 5 percent, histologic and experimental data, including those from the present study, suggest that the frequency of mural thrombosis is larger, even if heparin is used during the procedure. This is further suggested by the report of progressive lumen filling defects in humans after angioplasty, which decrease with the use of thrombolytic agents. In addition, such thrombi could characterize a subset at higher risk of late restenosis, favored by thrombus organization and growth-factor release due to enhanced platelet and macrophage activation. Even if the thrombus per se is not considered, such a finding might indicate more severe balloon-induced vascular injury, which is a known predictor of myointimal proliferation. More effective specific therapies could then be targeted to these patients. Our data indicate that arteriography is inadequate to delineate such a subgroup, even if only large thrombi are sought.