INCIDENCE, PREDISPOSING FACTORS, ACUTE CO MPLICATIONS, AND PROGNOSTICIMPLICATIONS OF INTRACORONARY THROMBUS FORMATION DURING PTCA

Besides coronary artery dissection, intracoronary thrombus formation i s known to be an important mechanism for acute coronary occlusion in t he course of percutaneous transluminal coronary angioplasty (PTCA). Th erefore, we analyzed 210 consecutive patients (217 dilated stenoses) t o define the incidence and potential predisposing clinical and morphol ogical factors of intracoronary thrombus formation. Intracoronary thro mbus formation was angiographically detectable in 11 % of the cases, a dissection in 21 %. Acute PTCA-related coronary occlusion (incidence = 5.5 %) was significantly associated with intracoronary thrombus form ation (p < 0.001) but less so with dissection (p = 0.074). Acute redil atation after an initially successful PTCA was almost exclusively nece ssary in patients with intracoronary thrombus formation (p < 0.001). U nivariate analysis demonstrated the following factors to be significan tly associated with intracoronary thrombus formation: Irregular lumen of stenosis (p = 0.006), stenosis at branch point (p = 0.012) and unst able angina pectoris (p = 0.001). Patients with intracoronary thrombus formation did not show a worse long-term prognosis regarding clinical events compared with a matched group (average follow-up of 20 months) . Conclusion: Luminal irregularities within the stenosis to be dilated and the clinical syndrome of unstable angina pectoris are predisposin g factors for PTCA-induced intracoronary thrombus formation, suggestin g that preexisting local activation of the coagulation system plays an independent role for intracoronary thrombus formation during PTCA. Al though intracoronary thrombus formation increases the risk for acute c omplications during PTCA, the long-term result is not adversely affect ed.