Relationship Between Prior PCI and Subsequent CABG

Dear Editor, With the number of percutaneous coronary interventions (PCIs) on the rise, it is expected that there will be a corresponding growth in population of patients with prior PCI referred to coronary artery bypass grafting (CABG) as a result of long-term PCI failure, incomplete revascularization, or coronary artery disease progression. The prevalent position of the interventional cardiologists of: ‘‘subsequent CABG may be successfully performed in any patient with a history of previous PCI’’ is now being seriously challenged. Furthermore, results of several studies that investigated the impact of previous PCI on subsequent CABG were found to be conflicting. For this reason, we read with great interest the article by Niclauss et al. regarding the influence of prior PCI on subsequent CABG. There are only a few studies reporting onmidor long-term results following surgical revascularization in patients with prior PCI, and from that point of view the article by Niclauss et al. is indeed a very fine contribution. This study produced another very important conclusion—there is no difference in terms of mortality depending on prior PCI status. However, a cautionary warning was identified in that particular study: the proportion of patients who underwent isolated percutaneous transluminal angioplasty (PTCA)—20% in PCI prior CABG group—looks to be far too big for contemporary clinical practice in our view. Having in mind different pathophysiological mechanisms responsible for PTCA and PCI failure, we believe that such a large number of patientsmight, in fact, skew the results of the study. We, therefore, think that excluding the subgroup of patients would yield results that would be more representative of a contemporary practice. In Table 1, it is indicated that a proportion of patients with prior myocardial infarction (MI) is very similar between the groups (40% vs. 44%, p1⁄4 0.07). Does this mean that the patients with MI were not treated with PCI in large number? The report did not appear to indicate the number of patients having previous MI treated with PCI that were subsequently referred to CABG. For the purpose of analysis, it would be useful to see in what percentage was the artery, already treated with stent, revascularized surgically. Another factor worthy of attention is the number of multiple PCIs and its influence on CABG. Based on our clinical practice, we know that cardiologists are likely to be very persistent in their attempts to percutaneously revascularize the artery. Table 2 of Niclauss et al. paper counts 22.3% (89) prior-PCI patients taking clopidogrel which seems quite low. We seek explanation about how long the patients took the drug following PCI. Again, 77.7% of patients with previous PCI were merged with those not submitted to PCI when the impact of active double anti-platelet therapy was investigated. We believe that conclusions would be more accurate (meaningful) if only the original groups were considered. Careful decision-making in the setting of multivessel disease is mandatory. Obviously, many risk factors (patient related, procedure related, drug related, coronary artery anatomy, and pathology) may influence the success or failure of specific procedures, thus emphasizing the need for adequate patient selection according to corresponding procedure type. In order to gain meaningful insight about the relation between PCI and subsequent CABG, more contemporary studies including a larger proportion of patients treated with drug eluting stents and/or biodegradable stents are highly warranted. Conflict of interest: The authors acknowledge no conflict of interest in the submission.