Polymer-free Sirolimus Eluting Stent: Real-world Investigation of Safety and Outcomes

Official title

POLARIS : POLymer-free Sirolimus Eluting Stent: Real-world Investigation of Safety and Outcomes

Overview

POLARIS is a prospective, single-centre, single-arm observational pilot registry evaluating the real-world safety and efficacy of the Focus np (Abluminus np, Concept Medical, Tampa, FL, USA) polymer-free sirolimus-eluting stent in consecutive adult patients undergoing percutaneous coronary intervention (PCI). The primary endpoint is target lesion failure (TLF) at 12 months, defined per Academic Research Consortium-2 (ARC-2) criteria as the device-oriented composite of cardiac death, target vessel myocardial infarction, and clinically indicated target lesion revascularisation. Patients treated since January 2021 will be retrospectively identified and prospectively consented, with follow-up through 5 years. The registry will provide the first Western clinical evidence on this CE-marked device and serve as a template for a future national Swiss multicentre registry.

Detailed description

BACKGROUND. Newer-generation drug-eluting stents (DES) remain associated with late stent-related adverse events at approximately 2% per year, driven by neoatherosclerosis, delayed endothelial healing, and chronic inflammation attributable to permanent polymer coatings. Polymer-free DES were developed to remove this substrate. The polymer-free sirolimus-based submicron carrier-eluting stent Focus np (Abluminus np, Concept Medical, Tampa, FL, USA) (after: study device) is a novel polymer-free sirolimus-eluting stent built on a thin-strut (73 micrometres) cobalt-chromium platform, with drug delivery via biodegradable phospholipid submicron carriers (200-300 nm) confined to the abluminal surface, and a proprietary fusion coating extending sirolimus up to 5 mm beyond the stent edges. The device received CE marking on 24 January 2020. Only limited non-randomized Indian clinical data exist; no Western clinical data have been published.

OBJECTIVES. Primary: to evaluate device-oriented safety and efficacy (TLF at 12 months) of the stent in an all-comer population undergoing PCI at Geneva University Hospitals. Secondary: TLF at 2 and 5 years; individual components of TLF (cardiac death, target vessel MI, clinically indicated target lesion revascularisation) at 30 days, 12 months, 2 years, and 5 years; patient-oriented composite endpoint (all-cause death, any MI, any revascularisation); stent thrombosis (definite / probable, ARC-2, with temporal classification); target vessel failure; major bleeding (BARC 3 or 5); all-cause mortality; and late lumen loss when angiographic follow-up is available.

DESIGN. Prospective, single-centre, single-arm observational registry (Category A research with human subjects per the Swiss Human Research Act). Hybrid enrolment: retrospective identification from January 2021, prospective consent, and prospective follow-up at 30 days, 12 months, 2 years, and 5 years via medical records and telephone interview.

POPULATION. All consecutive adult patients (\>= 18 years) treated with at least one study device stent at Geneva University Hospitals since January 2021, with an indication for PCI according to current European or American guidelines, able to provide written informed consent, and with sufficient knowledge of French, German, English, or Italian.

STATISTICS. Exploratory, descriptive analysis. Binary endpoints with Clopper-Pearson 95% confidence intervals; time-to-event analysis by Kaplan-Meier with Greenwood 95% CIs. Pre-specified exploratory subgroup analyses (sex, clinical presentation, diabetes, age, lesion complexity, stent length) presented as forest plots without between-group p-values. Sensitivity analyses include per-protocol, complete-case, landmark (30 days to 12 months), Fine-Gray competing-risk, and tipping point analyses. Analyses in Python (lifelines, pandas, scipy, statsmodels). Reporting follows STROBE.

Interventions

• Device Polymer-free sirolimus-based submicron carrier-eluting stent Focus np (Abluminus np, Concept Medical, Tampa, FL, USA)
  Thin-strut (73 micrometres) cobalt-chromium coronary stent with polymer-free submicron phospholipid carriers (200-300 nm) delivering sirolimus exclusively to the abluminal surface, and fusion coating extending sirolimus deposition up to 5 mm beyond the stent edges. CE-marked 24 January 2020. Available diameters 2.25-4.0 mm and lengths 8-40 mm. Manufactured by Concept Medical, Tampa, FL, USA. Implantation and peri-procedural care follow operator discretion and institutional standard of care.

Primary outcome measures

• Target Lesion Failure (TLF) [Time frame: 12 months]

Secondary outcome measures (10)

• Target Lesion Failure (TLF) at 2 and 5 years [Time frame: 2 years; 5 years]
• Cardiac death [Time frame: 30 days; 12 months; 2 years; 5 years]
• Target vessel myocardial infarction [Time frame: 30 days; 12 months; 2 years; 5 years]
• Clinically indicated target lesion revascularisation [Time frame: 30 days; 12 months; 2 years; 5 years]
• Patient-oriented composite endpoint (POCE) [Time frame: 12 months; 2 years; 5 years]
• Definite or probable stent thrombosis (ARC-2) [Time frame: Acute (0-24h), subacute (1-30d), late (30d-1y), very late (>1y), up to 5 years]
• Target vessel failure (TVF) [Time frame: 12 months; 2 years; 5 years]
• Major bleeding (BARC type 3 or 5) [Time frame: 12 months; 2 years; 5 years]
• All-cause mortality [Time frame: 12 months; 2 years; 5 years]
• Late lumen loss (mm) [Time frame: At clinically indicated follow-up angiography, up to 5 years]

Eligibility criteria

Inclusion criteria

• Age >= 18 years at the time of the index procedure.
• Percutaneous coronary intervention performed at Geneva University Hospitals between January 2021 and December 2025.
• Implantation of at least one study device
• Indication for PCI according to current European or American guidelines.
• Able and willing to provide written informed consent.
• Sufficient knowledge of French, German, English, or Italian to understand the patient information document.

Exclusion criteria

• Documented refusal to participate in research through opt-out from general consent.
• Inability to provide informed consent (cognitive impairment or other).
• Inability to be contacted for informed consent (no valid contact information, or unreachable after three contact attempts).
• Life expectancy less than 12 months due to non-cardiac comorbidities at the time of consent.
• Participation in another clinical trial that would interfere with the endpoints of this registry.

Criteria are shown verbatim from the registry (in English). Final eligibility is always assessed by the study center.

Healthy volunteers: No

Study design

Observational model

Cohort

Study locations

Switzerland · 1 center

• Geneva University Hospitals (HUG) - Service of Cardiology — Geneva

Publications

• Garcia-Garcia HM, McFadden EP, Farb A, Mehran R, Stone GW, Spertus J, Onuma Y, Morel MA, van Es GA, Zuckerman B, Fearon WF, Taggart D, Kappetein AP, Krucoff MW, Vranckx P, Windecker S, Cutlip D, Serruys PW; Academic Research Consortium. Standardized End Point Definitions for Coronary Intervention Trials: The Academic Research Consortium-2 Consensus Document. Circulation. 2018 Jun 12;137(24):2635-2 PMID 29891620
• Mehran R, Rao SV, Bhatt DL, Gibson CM, Caixeta A, Eikelboom J, Kaul S, Wiviott SD, Menon V, Nikolsky E, Serebruany V, Valgimigli M, Vranckx P, Taggart D, Sabik JF, Cutlip DE, Krucoff MW, Ohman EM, Steg PG, White H. Standardized bleeding definitions for cardiovascular clinical trials: a consensus report from the Bleeding Academic Research Consortium. Circulation. 2011 Jun 14;123(23):2736-47. doi: 1 PMID 21670242
• Thygesen K, Alpert JS, Jaffe AS, Chaitman BR, Bax JJ, Morrow DA, White HD; ESC Scientific Document Group. Fourth universal definition of myocardial infarction (2018). Eur Heart J. 2019 Jan 14;40(3):237-269. doi: 10.1093/eurheartj/ehy462. No abstract available. PMID 30165617

Identifiers

NCT: NCT07563231 · POLARIS · POLARIS v1 04.03.2026

Primary sources (government registries)

• ClinicalTrials.gov (US NIH)

View this study on ClinicalTrials.gov ↗