Total occlusions of coronary arteries (CTO) are a known problem in surgical and interventional cardiovascular therapy. Despite major technical advances in PCI, success rates are low but show significant impact on survival. In a recent analysis, we showed that most CTO vessels could be successfully revascularized in CABG surgery even when completely invisible in preoperative angiograms. Nevertheless, we have no proof that revascularizing a CTO leads to a better clinical outcome and aimed to analyze the clinical impact of complete revascularization (CR) of CTO on morbidity and mortality.
We analyzed 938 consecutive patients who underwent isolated on-pump CABG at our institution between 2014 and 2016. All preoperative angiograms were screened for CTOs and then scored using the Rentrop grading of collateral filling. A clinical database was established containing clinical patient characteristics, surgical information, preoperative risk scores, and long-term follow-up data. To compare patients with and without CTO (non-CTO) as well as patients with CTO plus CR opposed to incomplete revascularization (IR), a propensity score matching (PSM) was performed using binary logistic regression. Standardized differences were evaluated to assess postmatch balances. We generated 231 matched pairs for the first analysis as well as 64 for the latter. The method of Kaplan and Meier was used to determine survival, comparing cumulative events by log-rank (Mantel–Cox) test. The data were analyzed using IBM SPSS Statistics 25.
No significant differences in intraoperative measurements between pairs with CTO and non-CTO were seen except for a significantly longer cross-clamping time. Long-term survival showed no difference after 3 years (p = 0.65). To analyze the impact of IR on the postoperative outcome, all patients with CTO and CR were compared with patients with CTO and IR also using PSM. These 64 matches showed a strong tendency toward a survival benefit within the first 2 years when fully revascularized but no significant survival benefit after 3 years. Patients with badly collateralized CTOs seemed to have an equal outcome to patients with a highly collateralized CTOs.
Surgical revascularization of occluded arteries is feasible in most cases and should be aimed at to achieve CR. Patients might not benefit from it in the long run, but short-term survival seems to be dependent on CR even if the artery is chronically occluded.
