Coronary angioplasty in symptomatic patients after bypass surgery

Comparison of event and procedure rates following percutaneous transluminal coronary angioplasty in patients with and without previous coronary artery bypass graft surgery [the ROSETTA (Routine versus Selective Exercise Treadmill Testing after Angioplasty) Registry]

To compare 6-month post-percutaneous transluminal coronary angioplasty (PTCA) outcomes and cardiac procedure use among patients with and without prior coronary artery bypass graft (CABG) surgery, we examined 791 patients who were enrolled in the Routine versus Selective Exercise Treadmill Testing after Angioplasty (ROSETTA) Registry. The ROSETTA Registry is a prospective, multicenter registry that examines the use of functional testing after successful PTCA. Most patients were men (76%, mean age 61 +/- 11 years) who underwent single-vessel PTCA (85%) with stent implantation (58%). Baseline and procedural characteristics differed between patients with a prior CABG (n = 131) and patients with no prior CABG (n = 660), including Canadian Cardiovascular Society angina class III to IV (60% vs 49%, respectively, p = 0.03) and stenosis involving the proximal left anterior descending coronary artery (10% vs 22%, p = 0.004). Event rates among patients with prior CABG were higher than among patients with no prior CABG, including unstable angina (19% vs 11%, p = 0.02), myocardial infarction (2% vs 1%, p = 0.2), death (4% vs 2%, p = 0.08), and composite clinical events (22% vs 12%, p = 0.003). Furthermore, patients with prior CABG had higher rates of follow-up cardiac procedures, including angiography (24% vs 14%, p = 0.008) and PTCA (13% vs 7%, p = 0.04), but not repeat CABG (2% vs 3%, p = 0.8). A multivariate analysis that included baseline clinical and procedural characteristics demonstrated that prior CABG was a significant independent predictor of clinical events and cardiac procedure use (odds ratio 2.3, 95% confidence interval 1.5 to 3.5, p = 0.0001). Within the prior CABG group, patients with a PTCA of a bypass graft had a higher composite clinical event rate than patients with a PTCA of a native vessel (32% vs 17%, p = 0.05). In contrast, patients with a PTCA of a native vessel had event rates similar to those of patients with no prior CABG (17% vs 12%, p = 0.2). Thus, post-CABG patients have an increased risk of developing a cardiac event or needing a follow-up cardiac procedure during the 6 months after PTCA.

Postoperative symptomatic internal thoracic artery stenosis and successful treatment with PTCA

From 1988 to 1992, 4,182 coronary bypass grafting procedures were performed at the University of Ottawa Heart Institute. The left internal thoracic artery (ITA) was used in 2,913 patients, the right ITA in 79, and bilateral ITAs in 61 for a total of 3,053 patients with ITAs. This study assessed patients requiring angioplasty for symptomatic ITA stenosis after operation. A total of 29 patients (0.95%) with a mean age of 55.3 +/- 1.9 years underwent angioplasty for ITA stenosis from 4 days to 34 months after operation (mean, 6.5 +/- 1.6 months). Internal thoracic artery stenosis was identified in 18 patients (62.1%) within 3 months after operation. Angina was present in 26 patients (89.7%), a positive stress test in 8 (27.6%), and myocardial infarction in 1 (3.4%). At angiography, a total of 34 stenotic sites were identified in ITA grafts. Angioplasty was successful (< 50% residual stenosis) in 31 sites (91.2%). Follow-up was available for 28 of 29 patients (96.6%) at 24.6 +/- 2.3 months. Four patients (14.3%) returned with restenosis within 3 months, 2 of whom had successful repeat angioplasty, and 1 required reoperation. Canadian Cardiovascular Society anginal class after angioplasty was less than class II in 84.6% of patients. In conclusion, symptomatic postoperative ITA stenosis is uncommon, occurs most frequently at the site of distal anastomosis, and generally presents within 3 months of operation. It may be safely and effectively treated with angioplasty with a low recurrence rate.