Short summary

Coronary artery stenosis are treated with stent implantation. Newer stent types, called scaffolds, are made from a bioresorbable material, and support the vessel in the early phase after implantation when needed, but allow the vessel to obtain its original function and flexibility after absorption.

Previous studies have shown risk of lumen are reduced after 6 months. The hypothesis of this study is that optimal lesions preparation and aggressive balloon dilatation before implantation of a Magmaris scaffold is important to reduce lumen reduction.

Rationale

Bioresorbable scaffolds represent a novel technology in interventional cardiology and may lead to some potential long-term advantages including restoration of vasomotion, positive remodeling and a reduction in late complications. Intravascular imaging (Intravascular Ultrasound and Optical Coherence Tomography) can assess the scaffold-treated segment in detail including remodeling of the treated lesion, strut coverage, degradation and malapposition.

Aim: To investigate if a more intensive lesion preparation with a ScoreFlex balloon (a focused force-dilatation-balloon with a dual-wire-system which creates a focal stress pattern to facilitate controlled plaque modification at lower resolution pressure) compared to a standard non-compliant balloon will improve vascular healing and minimize lumen reduction in the scaffold-treated segment after implantation of a Magmaris scaffold. The primary endpoint is minimal lumen area after 6 months.

Description of the cohort

Eighty-two patients with stable angina and non-ST-segment elevation myocardial infarctions (NSTEMI) are included in the study, if they meet the inclusion criteria. Patients were eligible if;

1) age was between 18 and 80 years,

2) if they were admitted with NSTEMI confirmed with an elevated level of cardiac troponin T or I, or due to stable angina, and

3) if they were scheduled for PCI of a lesion (diameter stenosis > 50 % or visible thrombus) in a native coronary artery,

4) not vastly calcified,

5) suitable for treatment with Magmaris BVS complying with the scaffolds recommended limitations of coronary artery diameter between ≥ 2.75 mm and ≤ 4.0 mm.

Exclusion criteria were

1) patients participating in other randomized stent studies,

2) expected survival < 1 year,

3) allergy to aspirin, ticagrelor, clopidogrel or prasugrel,

4) allergy to sirolimus,

5) aorta-ostial lesions (cannot be cleared with flush by OCT),

6) serum creatinine > 150 µg/L (due to the required amount of contrast by OCT),

7) tortuous coronary arteries where the PCI-operator estimated that the introduction of an OCT-catheter would not be possible or would be associated with increased risk, and/or,

8) lesion length > 40 mm.

All patients admitted to Department of Cardiology, OUH will be screened for protocol inclusion and exclusion criteria before enrollment.

Data and biological material

Baseline characteristics

Procedural information at inclusion time

OCT scan (baseline - 6 months follow-up - 12 month follow-up)

IVUS scan (baseline - 6 months follow-up - 12 month follow-up)

Clinical follow-up (3 month (by telephone) - 6 month follow-up - 12 month follow-up)