The number of metallic layers affects efficacy of drug-coated balloons for in-stent restenosis

Hiroto Yabushita

Hiroto Yabushita and colleagues report in Circulation: Cardiovascular Interventions that drug-coated balloon treatment of in-stent restenosis lesions with three or more metallic layers results in a higher incidence of major adverse cardiovascular events and target lesion revascularisation than for lesions with one or two metallic layers. The authors also found that both haemodialysis and in-stent restenotic lesions with multiple metallic layers were independent predictors of major adverse cardiovascular events. In this commentary, Yabushita reviews the use of drug-coated balloons for in-stent restenosis.

In an accompanying commentary to our study, Fernando Alfonso and Javier Cuesta (Department of Cardiology, Hospital Universitario de La Princesa, Instituto de Investigación Sanitaria Princesa, Universidad Autónoma de Madrid, Spain) describe important aspects and limitations of our study1. For example, they indicate that our study provides important data regarding the use of drug-coated balloon treatment in patients with in-stent restenosis and also raises awareness of the need to consider the clinical implications of the number of previous metal layers.

The adverse clinical outcomes of drug-coated balloon use in patients with in-stent restenosis and ≥3 layers represented a novel finding. This may appear to be an expected outcome; however, our findings contradicted previous reports that suggested that the number of previous interventions did not significantly influence the effectiveness of drug-coated balloons in patients with in-stent restenosis. These studies did have some methodological issues, including details of noncompliant or scoring balloon usage, the type of drug-coated balloon, mandated angiographic follow-up, use of intracoronary imaging guidance, resistant calcified plaque, and lack of a control group. Furthermore, stent under-expansion on coronary imaging was required for the prediction of subsequent target vessel failure.

Drug-eluting stents are known to be more effective than drug-coated balloons in reducing the need for repeat target lesion revascularisation, particularly in patients with in-stent restenosis within a drug-eluting stent. As compared with drug-coated balloons, drug-eluting stents provide better acute and long-term angiographic results. Also, drug-coated balloons have a lower acute lumen gain and, eventually, a similar or even lower late lumen loss.

Nevertheless, several investigators and operators still believes that the marginally superior late angiographic results obtained with drug-eluting stents in these patients do not justify the systematic requirement of an additional metal layer (as would be the case with implanting another drug-eluting stent). Therefore, management of patients with recurrent in-stent restenosis represents a major therapeutic dilemma; in fact, the title of the Alfonso et al’s commentary is The therapeutic dilemma of recurrent in-stent restenosis. The implantation of a new drug-eluting stent is particularly a concern in patients with multiple metal layers. In this unique adverse scenario, the use of drug-coated balloons may provide a well-designed therapeutic strategy. Additional while drug-eluting stent implantation provides good acute results and midterm clinical outcome, it continuously stimulates a persistent vicious circle. Further research was necessary to resolve this therapeutic dilemma.

Therefore, the treatment of patients with in-stent restenosis and multiple previous stent layers continues to be a major challenge. In this setting, major efforts are required to aggressively tackle residual under-expansion and optimise the procedural results. Drug-coated balloon treatment represents a well-designed strategy for these patients; however, in our study, it provided unsatisfactory long-term outcomes in patients with ≥3 layers. A dedicated follow-up is required, particularly in patients treated with multiple metallic layers, because other “leave-nothing-behind strategies” (e.g. multiple metallic layers composed by repeated 2nd generation drug-eluting stent implantation, and narrowing vessel due to repeated stent implantation to small vessel or stent under-expansion.) have not been found to be superior to drug-coated balloon treatment in patients with in-stent restenosis.

If recurrent in-stent restenosis is observed in patients with ≥3 layers, an appropriate treatment should be performed, except for drug-coated balloon treatment, which requires medical treatment, further drug-eluting stent implantation, or coronary artery bypass grafting. Furthermore, additional treatment options should be considered with first and second restenoses, and the operator should try to avoid constructing multiple metallic layers (particularly with ≥3 layers).

Hiroto Yabushita is at Interventional Cardiology Unit, New Tokyo Hospital, Matsudo, Japan


  1. Alfonso F, Cuesta J. The therapeutic dilemma of recurrent in-stent restenosis. Circ Cardiovasc Interv 2018;11:e007109. DOI: 10.1161/CIRCINTERVENTIONS.118.007109


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