Paclitaxel-eluting balloons for sirolimus-eluting stent restenosis.

We read with interest the randomized study by Habara et al. (1) comparing paclitaxel-eluting balloon (PB) (n 25) with convenional balloon (BA) (n 25) in patients suffering from sirolimusluting stent (SES) in-stent restenosis (ISR). In these patients, PB rovided a dramatic improvement in angiographic parameters at ate follow-up, compared with BA. This information is timely, ecause ISR after drug-eluting stent (DES) implantation is beoming a growing concern due to the widespread use of DES in ncreasingly complex anatomic scenarios (2). This study nicely omplements a pioneer randomized trial where PB were also trikingly superior to BA in patients with bare-metal ISR (3). Actually, in-segment late angiographic loss after PB (0.03 mm) was even lower than that found in the present study in SES ISR (0.18 mm) (3). Considering the clinical implications of this small yet provocative study, clarifying some methodological issues would be of major practical value. First, SES ISR frequently locates at the stent edges (4). In this egard, data on the presence and implications of edge ISR with espect to the relative efficacy of PB over BA would be of major nterest (5). Second, SES underexpansion remains a frequent rigger for subsequent ISR (6). Therefore, if available, intravascular ltrasound data on the degree of stent expansion in these patients ould be also of value. Likewise, information on inflation presures, both during pre-dilation and especially at final optimization, ould be of great practical value, especially considering that elatively low pressures are recommended with PB. Third, after ES implantation, late angiographic findings (late loss, minial lumen diameter, percentage diameter stenosis) usually do ot follow a normal distribution (7). It would be of interest to now whether similar angiographic distribution patterns are een after PB. The excellent results obtained with PB in the current study are eassuring and open new venues in the management of patients ith DES ISR. We fully agree (2) with the suggestion that further tudies are warranted to confirm the efficacy of PB in ISR affecting ther DES types and also to assess the relative value of PB versus epeat DES implantation (i.e., RIBS IV [Restenosis Intrastent in rug-eluting stents: paclitaxel-eluting Balloon versus everolimusluting Stent] randomized study) in this challenging anatomic etting.