Drug-eluting balloons: what is their place on the interventionalist's shelf?

Late clinical outcomes for SeQuent please paclitaxel-coated balloons in PCI of instent restenosis and de novo lesions: A single-center, real world registry

OBJECTIVES

The aims of this study were to evaluate clinical outcomes following PCI using SeQuent Please paclitaxel-coated balloons (PCB) of ISR and denovo lesions (DNL), in all-comer patients at Liverpool Hospital, Sydney, Australia.

BACKGROUND

There have been promising results for PCI using drug-coated balloons; however, long-term data for clinical outcomes are lacking.

METHODS

Baseline patient demographics, PCI procedural details, and clinical outcomes were collected. The primary endpoint was the incidence of MACE, a composite of cardiac death, myocardial infarction (MI), and clinical-driven target lesion restenosis (TLR). The median follow-up for clinical events was 1.3 [0.6-1.9] years.

RESULTS

A total of 188 lesions (n = 147 patients) were treated with PCB, comprising 118 (63%) ISR lesions and 70 (38%) DNL. Patient mean age was 67 ± 11years, 79% were male, and 54% had type 2 diabetes mellitus (DM). MACE was recorded in 17 patients (12%), with cardiac death confirmed in 1 patient (0.7%). MACE was significantly lower for DNL than ISR (1% vs. 15%, P = 0.03), and PCB had favourable TLR for DNL. Cox regression demonstrated that DM (HR 7.17, 0.92-55.6, P = 0.05) and prior CABG (HR 3.22, 1.17-8.83, P = 0.02) were independent predictors of MACE for ISR lesions.

CONCLUSIONS

MACE rates were acceptable, with overall low incidence of cardiac death, MI, and TLR, for PCB treatment of ISR and DNL. Independent predictors of poor outcome in the ISR group were DM and prior CABG. The particularly low MACE for the DNL group supports direct PCB as a viable stent-sparing PCI strategy in challenging patients and lesion subsets. © 2016 Wiley Periodicals, Inc.

Paclitaxel-Eluting Balloon vs Standard Angioplasty to Reduce Restenosis in Diabetic Patients With In-Stent Restenosis of the Superficial Femoral and Proximal Popliteal Arteries: Three-Year Results of the DEBATE-ISR Study

PURPOSE

To report the 3-year safety and effectiveness outcomes from the prospective all-comers DEBATE-ISR study (ClinicalTrials.gov identifier NCT01558531) of symptomatic diabetic patients with femoropopliteal in-stent restenosis (ISR) undergoing treatment with paclitaxel-eluting balloons compared with historical diabetic controls.

METHODS

From January 2010 to December 2011, 44 consecutive diabetic patients (mean age 74±11 years; 32 men) were treated with drug-eluting balloons (DEBs) and enrolled in the study. The control group comprised 42 consecutive diabetic patients (age 76±7 years; 23 men) treated with conventional balloon angioplasty (BA) from 2008 to 2009.

RESULTS

No significant differences in terms of clinical, angiographic, or procedural characteristics were observed between the study groups. Critical limb ischemia was present in the majority of patients. Tosaka class III ISR was observed in more than half of the patients. Mean lesion length was 132±86 and 137±82 mm in the DEB and BA groups, respectively (p=0.7). At 3-year follow-up, the rate of target lesion revascularization (TLR) was 40% in the DEB group vs 43% in the BA group (p=0.8); Kaplan-Meier analysis showed no significant differences in terms of freedom from TLR. The presence of a Tosaka class III occlusion was associated with a worse outcome in both study groups (odds ratio 3.96, 95% confidence interval 1.55 to 10.1, p=0.004).

CONCLUSION

Using DEBs for femoropopliteal ISR yielded similar results to BA in terms of TLR at 3-year follow-up. The treatment of more complex ISR lesions was associated with an increased rate of TLR, irrespective of the technology used.

Drug-eluting balloon in the treatment of in-stent restenosis and diffuse coronary artery disease: real-world experience from our registry

OBJECTIVES

To report a single-center experience of drug-eluting balloons (DEB) in the treatment of in-stent restenosis (ISR) and de novo coronary artery disease.

BACKGROUND

DEB are emerging as an alternative treatment for coronary stenosis especially when metal scaffolding is undesirable (in-stent restenosis and small-vessel de novo disease). Although there are various randomized trials and registry studies, the data from real-world cohorts are lacking.

METHODS

Consecutive patients treated with the In.Pact Falcon™ (Medtronic Inc., Minneapolis, MN, USA) paclitaxel-eluting balloon between January 2009 and December 2011 were retrospectively studied. The measured end-points were cardiac death, myocardial infarction (MI), target lesion revascularization (TLR), target vessel revascularization (TVR), and major adverse cardiac events (MACE) defined as combination of cardiac death, MI, and TVR.

RESULTS

A total of 275 lesions were successfully treated in 184 patients. The mean age was 66.2 ± 9.6 years, and 87% were males. The predominant indication for DEB use was ISR (62%), with de novo lesions accounting for the remainder (38%). A mean of 1.48 ± 0.9 DEB were used per patient. Bailout stenting was required in 24% of lesions. The median clinical follow-up was 14.6 months (IQR 12-23). The overall rates of cardiac death, MI, TLR, TVR, and MACE were 3.8%, 1.6%, 16.8%, 17.9%, and 21.7%, respectively. The overall rate of stent thrombosis was 0.5% (n = 1).

CONCLUSION

Our results suggests that DEB can be considered in lesions where the use of stents is not desirable, especially restenotic lesions. Further long-term follow-up of these patients will provide us more insights on the long-term outcomes.

New technologies aimed at percutaneous intervention in the small coronary artery

Percutaneous coronary intervention (PCI) of small vessels can be complicated by technically difficult access to the target lesion, an increased risk of major adverse cardiac events and in-stent restenosis requiring repeat revascularization. Conventional management of such lesions is with drug-eluting stent implantation; however, these have only partly attenuated the problem. In response, several medical device companies are competing to produce new technologies aimed at PCI in small coronary arteries. Such innovations include thin-strutted stents, stent-on-a-wire systems, drug-coated balloons, endothelial progenitor cell-catching stents and biodegradable stent systems. To date, none of these techniques have been sufficiently validated for use in small coronary arteries to justify a change in practice; however, small-vessel coronary artery disease is an increasingly common problem, and PCI of target lesions with reference vessel diameter <3.0 mm is likely to increase, especially in view of the increasing prevalence of diabetes, warranting further well-designed studies. The prospect of mounting a self-expandable biodegradable drug-eluting stent directly onto a guidewire could potentially be an exciting future development.

The effect of polyethylene glycol structure on paclitaxel drug release and mechanical properties of PLGA thin films

Thin films of poly(lactic acid-co-glycolic acid) (PLGA) incorporating paclitaxel typically have slow release rates of paclitaxel of the order of 1 μg day(-1) cm(-2). For implementation as medical devices a range of zero order release rates (i.e. 1-15 μg day(-1) cm(-2)) is desirable for different tissues and pathologies. Eight and 35 kDa molecular weight polyethylene glycol (PEG) was incorporated at 15%, 25% and 50% weight ratios into PLGA containing 10 wt.% paclitaxel. The mechanical properties were assessed for potential use as medical implants and the rates of release of paclitaxel were quantified as per cent release and the more clinically useful rate of release in μg day(-1) cm(-2). Paclitaxel quantitation was correlated with the release of PEG from PLGA, to further understand its role in paclitaxel/PLGA release modulation. PEG release was found to correlate with paclitaxel release and the level of crystallinity of the PEG in the PLGA film, as measured by Raman spectrometry. This supports the concept of using a phase separating, partitioning compound to increase the release rates of hydrophobic drugs such as paclitaxel from PLGA films, where paclitaxel is normally homogeneously distributed/dissolved. Two formulations are promising for medical device thin films, when optimized for tensile strength, elongation, and drug release. For slow rates of paclitaxel release an average of 3.8 μg day(-1) cm(-2) using 15% 35k PEG for >30 days was achieved, while a high rate of drug release of 12 μg day(-1) cm(-2) was maintained using 25% 8 kDa PEG for up to 12 days.