920-49 Analysis of the Culprit Lesion and Clinical Events in Post-CABG Patients: Interim Angiographic Results from the Post-CABG Trial

Clinical events prompting angiography occur in patients post bypass surgery, and often necessitate repeat revascularization procedures. In these patients the culprit lesion may occur in either the native vessel or the graft. The Post CABG study, a 5 year trial aimed at reducing SVG closure in minimally symptomatic patients 1–11 years Post-CABG, offers a unique view into this problem, since this study requires an initial angiogram to document baseline graft patency. In a subgroup of Post-CABG patients in whom symptoms prompted an interim “clinically driven” angiogram, we compared the baseline and interim angiograms for the presence or absence of a culprit lesion defined as total occlusion, angiographic clot, lesion change ≥ 50% or lesion g 75% diameter stenosis. Of 1253 enrolled patients with at least one SVG patent, 127 patients with clinical events and analyzable interim angiograms were evaluated. Results Culprit Lesion None Graft Native Vessel n (pts.) 15 (11.8%) 66 (52.0%) 46 (36.2%) Age [baseline angio] (yrs) 65.5 (53-76) * 59.8 (45-73) † 60.4 (36-74) Male gender (%) 80 90.9 86.9 Time CABG-interim angio (mo) 77.1 ± 10 102.6 ± 3.2 † 90.3±5.1 ** Resultant PTCA/CABG (1%) 0/0 33.3/31.8 30.4/4.3 * none vs native vessel † none vs graft ** graft vs native vessel, p l 0.05 Clinical indications for angiography differed depending on the anatomic site of the culprit lesio R. Patients with graft culprit lesions more frequently had MI (30.8%) than patients with culprit native vessel lesions (11.1%) P l 0.05, or with no lesions (0%) Conclusions In Post-CABG patients with clinical events that necessitated repeat angiography, only one-half had graft disease as the identifiable cause. No responsible lesion was found in 12%. Treatment for symptomatic patients following coronary artery bypass surgery may differ substantially depending on the anatomic cause of symptoms.