Coronary magnetic resonance imaging after routine implantation of bioresorbable vascular scaffolds allows non-invasive evaluation of vascular patency

<div><p>Background</p><p>Evaluation of recurrent angina after percutaneous coronary interventions is challenging. Since bioresorbable vascular scaffolds (BVS) cause no artefacts in magnetic resonance imaging (MRI) due to their polylactate-based backbone, evaluation of vascular patency by MRI might allow for non-invasive assessment and triage of patients with suspected BVS failure.</p><p>Methods</p><p>Patients with polylactate-based ABSORB-BVS in proximal coronary segments were examined with 3 Tesla MRI directly (baseline) and one year after implantation. For assessment of coronary patency, a high-resolution 3D spoiled gradient echo pulse sequence with fat-saturation, T2-preparation (TE: 40 ms), respiratory and end-diastolic cardiac gating, and a spatial resolution of (1.08 mm)³ was positioned parallel to the course of the vessel for bright blood imaging. In addition, a 3D navigator-gated T2-weighted variable flip angle turbo spin echo (TSE) sequence with dual-inversion recovery black-blood preparation and elliptical k-space coverage was applied with a voxel size of (1.14 mm)³. For quantitative evaluation lumen diameters of the scaffolded areas were measured in reformatted bright and black blood MR angiography data.</p><p>Results</p><p>11 patients with implantation of 16 BVS in the proximal coronary segments were included, of which none suffered from major adverse cardiac events during the one year follow up. Vascular patency in all segments implanted with BVS could be reliably assessed by MRI at baseline and after one year, whereas segments with metal stents could not be evaluated due to artefacts. Luminal diameter within the BVS remained constant during the one year period. One patient with atypical angina after BVS implantation was noninvasively evaluated showing a patent vessel, also confirmed by coronary angiography.</p><p>Conclusions</p><p>Coronary MRI allows contrast-agent free and non-invasive assessment of vascular patency after ABSORB-BVS implantation. This approach might be supportive in the triage and improvement of diagnostic workflows in patients with postinterventional angina and scaffold implantation.</p><p>Trial registration</p><p>German Register of Clinical Studies <a target="_blank">DRKS00007456</a></p></div

1-year follow up data.

<p>1-year follow up data.</p

Baseline and procedural characteristics.

<p>Baseline and procedural characteristics.</p

Multiple BVS implantation in the left anterior descending artery (LAD).

<p>Left: result in the coronary angiogram with 3 proximal and overlapping scaffolds. One drug eluting stent (SYNERGY 2.5/20mm) was implanted distally, since BVS was not deliverable to this area. MRI at baseline shows open scaffolds in 3D FLASH and 3D TSE, while the distal DES causes significant artefacts not allowing for judgement of vessel patency. Especially the black blood 3D TSE sequences confirm open scaffolds at baseline and after one year in this symptom-free patient.</p