Bifurcation lesions: no need to implant two stents when one is sufficient!

This editorial refers to ‘Coronary bifurcation lesions treated with simple or complex stenting: 5-year survival from patient-level pooled analysis of the Nordic Bifurcation study and the British Bifurcation Coronary Study’†, by M.W. Behan et al., on page 1923. The title of this Editorial seems an obvious statement; nevertheless, the question relating to a one- vs. two-stent strategy for bifurcation lesions has generated years of controversy and a large number of observational and randomized studies.1–6 At present, we can state that regarding whether to choose a one- or two-stent strategy, there are two types of bifurcation lesion. The first is lesions which require two stents as intention to treat. This type was not included in the randomized studies comparing the different strategies and it would be inappropriate to randomize a lesion to one stent which clearly needs two stents. The second type is lesions where either one or two stents could be used. For these lesions, it is better to implant one stent and crossover to two stents only if required. Figure 1 summarizes our proposed approach to a bifurcation lesion. A proposed approach to a bifurcation lesion: MB, main branch, SB, side branch. (Angiograms reproduced with kind permission from courtesy of Dr. Slayman Obeid, University Hospital Zurich). The second statement is further confirmed and supported by the study of Miles William Behan et al. presenting the 5-year follow-up of the NORDIC I Bifurcation and The British Bifurcation Coronary Study: Old, New, and Evolving Strategies (BBC ONE) studies.7 Before going into detail, it is appropriate to point out, as the authors did, some limitations of the two original studies: (i) both studies were performed with first-generation drug-eluting stents (DES) with clear disadvantages when compared with the current stents; (ii) in complex bifurcations, the procedures were performed suboptimally, with <75% kissing balloon inflations; (iii) approximately one-third of the lesions were simple bifurcations and not appropriate for a two-stent strategy by current standards; and (iv) approximately one-third of the patients presented with acute coronary syndromes, and the usage of newer antiplatelet agents would now be considered. Despite some differences in trial design, mainly in the criteria for crossover to a two-stent from a one-stent strategy and presence of angiographic follow-up, we can state that broadly there were many similarities, including open label design, type of endpoints assessed, and complex stenting techniques. Of note, although the NORDIC trial had stricter criteria for side branch stenting than the BBC ONE trial, the rate of side branch stenting in the provisional group was low and did not differ significantly between the trials (4.3% vs. 3%, P = 0.33). Dual antiplatelet therapy was mandated for 6 months in the 413 NORDIC I patients and for 9 months in the 500 patients enrolled in the BBC ONE trial. An important limitation was the usage of the paclitaxel-eluting stent (Taxus, Boston Scientific Corp, Natick, MA, USA) in the BBC ONE study. It is now accepted that this stent has a higher rate of stent thrombosis compared with other DES.8,9 The authors were able to collect 5-year follow-up data in 97% of patients. The most important finding is shown in their figure 2 demonstrating two remarkable facts: (i) the 5-year mortality was 3.8% for the one-stent strategy and 7% for the two-stent strategy (P = 0.04); and (ii) the survival curves start to separate at 2 years. At first glance, we are tempted to conclude that the higher mortality is due to very late stent thrombosis. Nevertheless, we are surprised to see an almost double mortality rate in the NORDIC I study employing the sirolimus-eluting stent (Cypher, Cordis, Johnson and Johnson, Bridgewater, NJ, USA) compared with the BBC ONE trial. The fact that the investigators reported all-cause mortality and not cardiovascular death is an important limitation, and we cannot dismiss entirely that these findings could be a ‘play of chance’. However, the message remains clear, even if we assume that there is no difference in mortality, when the operator can implant one stent in a bifurcation lesion, this strategy is not inferior and may even be superior to the routine implantation of two stents. The emergence of second-generation DES, with lower thrombosis rates, should not alter the above statement because even if superiority is lost due to lower event rates, a simpler strategy will still prevail as long as it does not prove to be inferior to a more complex one. Conflict of interest: none declared.