BiOSS LIM C: thin-strut cobalt-chromium version of the dedicated bifurcation stent

Acute and long-term results of percutaneous coronary intervention of bifurcation lesions with the dedicated Bioss Lim C stent: the Italian BIfurcation Observational Spontaneous Study (IBIOSS)

BACKGROUND

Percutaneous coronary intervention (PCI) for bifurcation lesions still represents a clinical challenge. The Bioss Lim C is a dedicated device for bifurcation lesions, features a tapered shape and large cells, and thus appears as a promising adjunct to the current interventional cardiologists' armamentarium. We aimed at conducting a prospective multicenter study focusing on early and long-term results after Bioss Lim C implantation for true coronary bifurcation lesions.

METHODS

Patients with true bifurcation lesions in whom Bioss Lim C implantation was attempted were enrolled in four Italian centers. An explicit bifurcation management approach was recommended, leaving however the choice between one- vs. two-stent strategies at operator's discretion. Acute and long-term results were systematically appraised, focusing on an acute composite of complex side branch (SB) rewiring, SB pinching, or SB occlusion (primary efficacy endpoint), as well as major adverse events (MACE, i.e. death, myocardial infarction [MI], or target vessel revascularization [TVR]), individual components of MACE, and stent thrombosis.

RESULTS

A total of 207 patients were included, with age of 67.3±10.8 years, and 40 (19.3%) women. The target lesion was located in the left main in 48 (23.2%) patients, whereas proximal reference vessel diameter was 3.69±0.48 mm, and lesion length 20.3±3.4 mm. According to the Medina classification, most patients (60 [30.9%]) had 1-1-1 lesions. Drug-eluting stent implantation in the SB was carried out in 19 (9.3%) subjects, and kissing balloon inflation was used in 67 (32.5%). The primary efficacy endpoint occurred in 27 (13.0%), with side branch (SB) occlusion in two (1.0%), SB pinching in 23 (11.1%), and complex SB rewiring in six (2.9%), and was most frequent in patients with lower body mass index or dyslipidemia. After 24.1±19.5 months, MACE were adjudicated in 23 (11.1%) subjects, with death in 10 (4.8%), MI in six (2.9%), and TVR in seven (3.4%), as well as stent thrombosis in one (0.5%).

CONCLUSIONS

This study supports a wider adoption of the Bioss Lim C dedicated bifurcation device, thanks to the favorable acute results as well as long-term clinical outcomes, as well as its versatility for the stenting strategy provisionally or eventually adopted by operators.

Clinical outcomes of a dedicated bifurcation stent system

INTRODUCTION

Percutaneous coronary intervention (PCI) of bifurcation lesions is technically challenging and associated with higher rates of complications such as stent thrombosis or in-stent restenosis. In this paper, we present the clinical outcomes of BiOSS LIM C (Balton, Poland), a dedicated bifurcation stent.

METHODS

In this retrospective single-center study we analyzed the outcome of patients with bifurcation coronary artery disease treated with the BiOSS LIM C stent system. The primary endpoint was the cumulative rate of major adverse cardiac events (MACE) including cardiac death, myocardial infarction (MI) and target lesion revascularisation (TLR) at the longest available follow-up.

RESULTS

The study population consisted of 25 patients (mean age 73.6 ± 9.7 years, 25 % females). In 80 % of the cases (n = 20) BiOSS LIM C stent was implanted in the left main coronary artery. Intravascular imaging was used in 70 % of the cases and an additional regular drug-eluting stent (DES) was deployed in the side branch in 24 % of the cases. The device success rate was 100 % and we observed no in-hospital adverse events. At a median follow-up of 15 ± 6 months, the MACE rate was 56 %, cardiac death was 4 %, and clinically driven TLR was 55 %. One patient died in the LM subgroup, 5 months after the index PCI, due to NSTEMI complicated by cardiogenic shock. Two patients died due to non-cardiac causes.

CONCLUSIONS

In this consecutive series of patients treated with BiOSS LIM C in major coronary bifurcation lesions, mostly in the left main stem, the mid-term clinical outcomes demonstrated a high incidence of major adverse events, mainly caused by TLR, despite an adequate implantation technique.

6-year results of BiOSS stents in coronary bifurcation treatment

BACKGROUND

The wide variation in bifurcation anatomy has generated an ongoing search for stents explicitly designed for coronary bifurcations, and to date, results have been underachieved.

METHODS

The POLBOS I and POLBOS II were international, multicentre, randomized, open-label, controlled trials. Patients were randomly assigned to BiOSS Expert (in POLBOS I, biodegradable polymer eluting paclitaxel)/BiOSS LIM (in POLBOS II, biodegradable polymer eluting sirolimus) stent implantation or regular drug-eluting stent (rDES) deployment. A provisional T-stenting strategy was the default treatment option. The primary endpoint of this pooled data study was the cumulative rate of major adverse cardiovascular events (MACE) consisting of cardiac death, myocardial infarction (MI) and target lesion revascularization (TLR). Telephone follow-up was performed annually up to 72 months. (ClinicalTrials.gov Identifier: POLBOS I-NCT02192840, POLBOS II-NCT02198300).

RESULTS

The total study population consisted of 445 patients, 222 patients in the BiOSS group and 223 patients in the rDES group. The follow-up rate was 93.7% in the BiOSS group and 91.9% in the rDES group. At 72 months, there was no significant difference between BiOSS and rDES groups regarding MACE (25.7% vs 25.1%, HR 1.06, 95% CI 0.73-1.52), cardiac death (3.1% vs 4.0%, HR 0.94, 95% CI 0.43-2.34), MI (3.6% vs 4.9%, HR 0.76, 95% CI 0.32-2.89), TLR (18.9% vs 16.1%, HR 1.17, 95% CI 0.75-1.83) and stent thrombosis rates (0.9% vs 0.5%, HR 1.21, 95CI 0.75-2.09).

CONCLUSIONS

At the 6-year follow-up, clinically significant clinical events did not differ between BiOSS stents and rDES.

Comparison of overexpansion capabilities and thrombogenicity at the side branch ostia after implantation of four different drug eluting stents

Interventions in bifurcation lesions often requires aggressive overexpansion of stent diameter in the setting of long tapering vessel segment. Overhanging struts in front of the side branch (SB) ostium are thought to act as a focal point for thrombi formation and consequently possible stent thrombosis. This study aimed to evaluate the overexpansion capabilities and thrombogenicity at the SB ostia after implantation of four latest generation drug-eluting stents (DES) in an in-vitro bifurcation model. Four clinically available modern DES were utilized: one bifurcation dedicated DES (Bioss LIM C) and three conventional DES (Ultimaster, Xience Sierra, Biomime). All devices were implanted in bifurcation models with proximal optimization ensuring expansion before perfusing with porcine blood. Optical coherence tomography (OCT), immunofluorescence (IF) and scanning electron microscope analysis were done to determine thrombogenicity and polymer coating integrity at the over-expanded part of the stents. Computational fluid dynamics (CFD) was performed to study the flow disruption. OCT (p = 0.113) and IF analysis (p = 0.007) demonstrated lowest thrombus area at SB ostia in bifurcation dedicated DES with favorable biomechanical properties compared to conventional DES. The bifurcated DES also resulted in reduced area of high shear rate and maximum shear rate in the CFD analysis. This study demonstrated numerical differences in terms of mechanical properties and acute thrombogenicity at SB ostia between tested devices.