Predictors of CABG Within One Year of Successful PTCA: A Retrospective, Case-Control Study

Abstract

Background. We previously have established characteristics predictive of the need for coronary artery bypass grafting (CABG) over many years after successful percutaneous transluminal coronary angioplasty (PTCA). In this study, we examined the factors associated with the need for CABG within 1 year of successful PTCA, and the recent impact of newer, catheter-based technologies. Methods. From January 1982 through December 1995, 234 patients underwent CABG within 1 year of a successful “index” PTCA at our hospital. Emergency operations within 12 hours of index PTCA were excluded. These cases were matched with 234 controls who underwent a successful index PTCA but did not require a subsequent CABG during the next year. Cases were matched by the date of their index PTCA, and 1-year follow-up was complete for all patients. Results. Before index PTCA there were no differences between the groups in terms of age, sex, diabetes, prior myocardial infarction, ejection fraction, duration of anginal symptoms, hypertension, hyperlipidemia, family history, or obesity (all nonsignificant). At index PTCA the cases had a greater mean number of lesions measuring 70% or greater compared with the controls (2.8 versus 1.8, respectively; p < 0.0001). The cases were more likely to have critical (70% or greater) proximal left anterior descending artery, proximal first obtuse marginal artery, and right posterior descending artery stenoses. The use of stents or atherectomy devices was not significantly more common among the controls (21% of controls versus 17.1% of cases; p = 0.35). Complete revascularization was achieved in significantly fewer of the cases than the controls (91 versus 156, respectively; p < 0.0001). The cases underwent CABG at a mean of 3 months (86% within 6 months) after PTCA. Among those who had a diagnostic catheterization, 52% of the patients had both restenosis of a dilated lesion and progression of other disease. Only 5 of 75 patients who had restenosis of a dilated lesion had a stent or an atherectomy device used at index PTCA. Of note, 13% (30 of 234) required an emergency operation, with an overall operative mortality rate of 3% (7 of 234). Conclusions. Although the likelihood of local restenosis is decreased by newer interventional techniques, the need for CABG within 1 year after successful PTCA is not diminished. The number of critical lesions and their location are the best predictors of the need for early CABG. If early post-PTCA CABG is to be avoided, patients who cannot be completely revascularized by PTCA should be revascularized by CABG.