Response to drug-eluting stent in-stent restenosis and re-restenosis: A hard time story.

Dear Dr. Najm,

We are grateful to Dr. Violeta Dinesch for his interest in our article on drug eluting stent (DES)-associated restenosis, and for his valuable comments.

Actually, the retrospective nature of our study is a clear limitation which precludes tracking and analysis of relevant data as that raised by Dr. Dinesch. As we have mentioned in our study methods [1], the decision of treatment between balloon angioplasty (BA) and implantation of another DES was left to the operator’s discretion. According to our study, the operators preferred repeated DES strategy with bifurcation lesions and chronic total occlusions, and IVUS-guidance was more frequently utilized. However, this was not the case with DES re-restenosis patients. The small number of this patient group (39 patients) precludes drawing consistent criteria upon which the operators would have probably built their treatment decision.

Kokura memorial hospital, where the study has been conducted, follows rigorously standardized protocols for percutaneous coronary interventions (PCI). Our study was conducted between 2006–2008, during which the DES utilized in the hospital were of the first generation (Cypher and Taxus). According to the institutional protocols, and as previously noted in our study methods, a switch strategy (Hetero-DES) was adopted in all cases, including those with DES re-restenosis. Nevertheless, whether or not to adopt a switch strategy in DES-associated restenosis is still a matter of debate [2], [3], even with second-generation DES [4].

Basically, our study throws a stone in stagnant water, by reporting long-term clinical and angiographic follow-up findings among patients with DES-associated restenosis and re-restenosis, exploring different treatment modalities. Further, prospective sufficiently powered studies should further unravel the conflict associated with such disease entity, in the absence of clear consensus as to which treatment modality is by far the best.