Response to Zakkar et al
Do we have sufficient information to guide our choice of therapy for chronic total occlusions (CTOs)? The articles by Weintraub and Garratt (“we” in this rebuttal) and Zakker et al are complementary. Zakker et al are highly critical of technical limitations and outcomes of percutaneous coronary intervention for CTOs, stressing the technical advantages of coronary artery bypass graft (CABG) for CTOs, covering a number of the same studies as Weintraub and Garratt. We placed less emphasis on technical ability to perform CABG for CTOs and more on case selection, the importance of viable myocardium, and clinical outcomes. We stressed that the literature concerning outcomes of CABG for CTOs is limited and that additional studies are needed. Overall comparisons of CABG to percutaneous coronary intervention, such as the Synergy Between Percutaneous Coronary Intervention With Taxus and Cardiac Surgery (SYNTAX) trial, or of percutaneous coronary intervention to medical therapy, such as the Clinical Outcomes Utilizing Revascularization and Aggressive Drug Evaluation (COURAGE) trial, cannot directly address the issue of whether to perform CABG for CTOs. The only randomized comparison of CABG to percutaneous coronary intervention was in a subset of the SYNTAX trial that included 543 CTOs, which found more complete revascularization with CABG. Complete revascularization is a surrogate; presumably, this SYXTAX subset was too small to compare clinical outcomes. We also learned little from nonrandomized comparative effectiveness studies of CABG for CTOs. Even excellent uncontrolled observational studies, such as the one by Holzhey et al, can only tell us that CABG for total occlusions can be performed; it cannot tell us whether CABG improved outcomes. We think it can be agreed that our data are inadequate and that randomized trials would offer considerably better information to guide clinical decisions. In the meantime, careful case selection, preferably with assessment of viability, is appropriate.
- © 2016 American Heart Association, Inc.