Vascular response following implantation of the third-generation drug-eluting resorbable coronary magnesium scaffold: an intravascular imaging analysis of the BIOMAG-I first-in-human study

BACKGROUND

The 12-month outcomes of BIOMAG-I - the first-in-human study investigating the third-generation drug-eluting resorbable magnesium scaffold (DREAMS 3G) - showed promising results regarding clinical outcomes and late lumen loss.

AIMS

The current study aimed to investigate vascular healing parameters assessed by optical coherence tomography (OCT) and intravascular ultrasound (IVUS), focusing on strut visibility, vessel and scaffold areas, and neointimal growth patterns.

METHODS

This is a BIOMAG-I substudy including patients with available serial OCT and IVUS data. We conducted a frame-based analysis of OCT findings in conjunction with IVUS-derived vessel and scaffold areas, evaluating the qualitative and quantitative aspects of vascular healing.

RESULTS

Among the 116 patients enrolled in this trial, 56 patients treated with DREAMS 3G were included in the analysis. At 12 months, OCT imaging revealed that 99.0% of the struts were invisible, and no malapposed struts were depicted. While the vessel area showed no significant difference between the timepoints, the minimum lumen area significantly decreased from post-percutaneous coronary intervention to 6 months (6.88 mm2 to 4.75 mm2; p<0.0001), but no significant changes were observed between 6 and 12 months. Protruding neointimal tissue (PNT) - a unique neointimal presentation observed following resorbable magnesium scaffold implantation - was observed in 89.3% of the study patients at 12 months, and its area exhibited a 47.4% decrease from 6 to 12 months.

CONCLUSIONS

This imaging substudy revealed that, at 12-month follow-up, virtually all struts of the DREAMS 3G scaffold became invisible, without evident malapposition. The vascular healing response to DREAMS 3G implantation also appeared favourable up to 12 months, which is indicated by advanced strut degradation and spontaneous regressing PNT between 6 and 12 months.

Magnesium-based resorbable scaffold vs permanent metallic sirolimus-eluting stent in patients with ST-segment elevation myocardial infarction: 3-year results of the MAGSTEMI randomised controlled trial

BACKGROUND

The long-term safety and performance of magnesium-based bioresorbable scaffolds (MgBRS) in ST-segment-elevation myocardial infarction (STEMI) patients are uncertain.

AIMS

The aim of this study was to report the 3-year clinical outcomes of the MAGSTEMI trial.

METHODS

This investigator-driven, multicentre, randomised, single-blind, controlled trial randomised STEMI patients 1:1 to MgBRS or to permanent metallic sirolimus-eluting stents (SES) at 11 academic centres. The main secondary endpoints included device-oriented composite endpoints (DoCE) and patient-oriented composite endpoints (PoCE), their individual components, any bleeding, and device thrombosis rate. All endpoints were defined according to the Academic Research Consortium. Events were adjudicated by an independent committee.

RESULTS

Three-year clinical follow-up was obtained in 142 (90.0%) patients. At 3-year follow-up, MgBRS were associated with a higher rate of DoCE than SES (13 [17.6%] vs 5 [6.6%], diff -11.0 [95% CI: -21.3 to -0.7]; p=0.038). This difference was driven by an increased incidence of DoCE within the first year of follow-up. In the landmark analysis, there was no difference between 1 and 3 years (0 [0.0%] vs 1 [1.4%]; p=1.000). The difference in the rate of DoCE was driven by a higher incidence of target lesion revascularisation (TLR) in the MgBRS group compared to SES (12 [16.2%] vs 4 [5.3%]; diff -10.9% [95% CI: -20.7 to -1.2]; p=0.030). The difference in TLR was observed during the first year, with no further differences observed between 1 and 3 years (0 [0.0%] vs 1 [1.4%]; p=1.000).

CONCLUSIONS

At 3-year follow-up, MgBRS were associated with a higher rate of TLR, which was clustered within the first year, compared to SES.

Management of in-stent restenosis

In-stent restenosis (ISR) remains the most common cause of stent failure after percutaneous coronary intervention (PCI). Recent data suggest that ISR-PCI accounts for 5-10% of all PCI procedures performed in current clinical practice. This State-of-the-Art review will primarily focus on the management of ISR but will begin by briefly discussing diagnosis and classification. We then move on to detail the evidence base underpinning the various therapeutic strategies for ISR before finishing with a proposed ISR management algorithm based on current scientific data.