One-year results of the INSPIRE trial with the novel MGuard stent: Serial analysis with QCA and IVUS

Impact of a micro-net mesh technology covering stent on coronary microvascular dysfunction in patients with high thrombus burden

BACKGROUND

Highly thrombotic coronary lesions continue to be a serious and clinically significant problem that is not effectively and completely addressed by current technology.

OBJECTIVES

We aimed to investigate whether a micro-net mesh (MNM) technology covering stent could preserve the index of microcirculatory resistance (IMR) after percutaneous coronary intervention (PCI) in patients with high thrombus burden.

METHODS AND RESULTS

Fifty-two patients with non-ST elevation myocardial infarction or ST Elevation Myocardial Infarction and high thrombus burden (TIMI thrombus grade ≥ 3) were randomized into two groups, PCI with a MNM covering stent (MNM group, n = 25) and PCI with any commercially available stent (DES group, n = 27). As the primary endpoint, IMR was measured immediately after PCI using a pressure-temperature sensor-tipped coronary wire. The secondary endpoint was left ventricular ejection fraction (LVEF) at 6 months of follow-up. The IMR in the MNM group was significantly lower in comparison to the DES group (33.2 [21.3, 48.9] vs. 57.2 [39.9, 98.0], p = 0.005). No significant differences were observed in baseline LVEF (54.5 ± 10.2% vs. 53.1 ± 6.87%, p = .57), while LVEF was significantly improved at follow-up in the MNM group (61.1 ± 7.1% vs. 53.9 ± 6.35%, p = .0001).

CONCLUSION

MNM technology significantly improved coronary microvascular dysfunction after PCI in patient with acute coronary syndrome and appears as a useful technological option for thrombus management.

Endogenous adenosine maintains cartilage homeostasis and exogenous adenosine inhibits osteoarthritis progression

Osteoarthritis (OA) is characterized by cartilage destruction and chondrocytes have a central role in this process. With age and inflammation chondrocytes have reduced capacity to synthesize and maintain ATP, a molecule important for cartilage homeostasis. Here we show that concentrations of ATP and adenosine, its metabolite, fall after treatment of mouse chondrocytes and rat tibia explants with IL-1β, an inflammatory mediator thought to participate in OA pathogenesis. Mice lacking A2A adenosine receptor (A2AR) or ecto-5′nucleotidase (an enzyme that converts extracellular AMP to adenosine) develop spontaneous OA and chondrocytes lacking A2AR develop an ‘OA phenotype' with increased expression of Mmp13 and Col10a1. Adenosine replacement by intra-articular injection of liposomal suspensions containing adenosine prevents development of OA in rats. These results support the hypothesis that maintaining extracellular adenosine levels is an important homeostatic mechanism, loss of which contributes to the development of OA; targeting adenosine A2A receptors might treat or prevent OA.

Osteoarthritis (OA) is a debilitating and destructive joint disease for which disease modifying drugs are not available. Here the authors show that extracellular adenosine signalling via the A2AR receptor on chondrocytes is needed to prevent OA and that liposome-bound adenosine injection can treat the pathology in rats.

Impact of thrombus burden on outcomes after standard versus mesh-covered stents in acute myocardial infarction (from the MGuard for acute ST elevation reperfusion trial)

Large thrombus burden negatively affects the results of percutaneous coronary intervention (PCI) for acute ST-segment elevation myocardial infarction (STEMI). We investigated the impact of thrombus burden in patients with STEMI undergoing primary PCI with the mesh-covered MGuard stent (InspireMD Ltd., Tel Aviv, Israel) versus a control bare-metal or drug-eluting stent. In 433 patients with STEMI randomized to the MGuard stent versus a control stent, angiographically visible thrombus was identified in 383 patients (88.5%), with median thrombus area 30.15 mm(2) (22.70, 41.93). Lesions with large thrombus (area > median) were treated with more frequent use of manual aspiration (80.8% vs 65.8%, p = 0.0009) and longer (22.1 ± 5.9 vs 19.4 ± 5.4 mm, p <0.0001) and larger (3.46 ± 0.40 vs 3.29 ± 0.36 mm, p <0.0001) stents. PCI of lesions with large thrombus burden had more thrombotic complications (30.6% vs 15.9%, p = 0.0007) and reduced angiographic success (80.3% vs 91.1%, p = 0.003). In large thrombus lesions, the MGuard stent was more effective than control stents in achieving Thrombolysis In Myocardial Infarction-3 flow (87.9% vs 74.5%, p = 0.02) and tended to result in less slow flow or no reflow (8.8% vs 17.6%, p = 0.07). ST-segment resolution was improved with the MGuard, and clinical outcomes were favorable in both stent groups, regardless of thrombus burden. In conclusion, reperfusion success is reduced after primary PCI in lesions with large thrombus burden, an outcome that may be modified by the MGuard stent.

MGuard® stent retrieval after failed implantation and withdrawal

SUMMARY

We present two cases of right coronary artery occlusion in which MGuard® stent implantation failed for different causes, leading to a retrieval procedure adapted to the situation. Complete retrieval was possible in both cases. These cases illustrate the need for careful selection of the lesions that are going to be treated with this type of stent, for which pre-dilatation is recommended in severe lesions located just after an acute vessel angle, the evaluation of proximal angulation and calcification, as well as strategies for complete retrieval in case of implantation failure.

Microvascular coronary flow comparison in acute myocardial infarction angioplasty treated with a mesh covered stent (MGUARD stent) versus bare metal stent: MICAMI-MGUARD

BACKGROUND

Distal embolization of thrombus/platelet aggregates decreases myocardial reperfusion during primary percutaneous coronary intervention (PCI), and is associated with worse immediate and long-term prognosis of patients with ST-elevation myocardial infarction (STEMI).

OBJECTIVE

Assess the efficacy of a mesh covered stent (MGuard™ stent, MGS) in preventing distal embolization and microvascular reperfusion impairment during primary PCI, compared with a bare metal stent (BMS).

METHODS

Forty patients with STEMI referred for primary PCI were randomized for stenting the culprit lesion with the MGS (n = 20) or a BMS (n = 20). Blinded experts performed off-line measurements of angiographic epicardial and microvascular reperfusion criteria: TIMI flow grade, myocardial blush, corrected TIMI frame count (cTFC).

RESULTS

At baseline clinical, angiographic and procedural variables were not different between groups. Post PCI TIMI flow grade was similar in both groups. We observed better myocardial Blush grade in group MGS compared to BMS (median value 3.0 vs 2.5, 2p = 0.006) and cTFC (mean cTFC: MGS 19.65 ± 4.07 vs BMS 27.35 ± 7.15, 2p < 0.001, cTFC mean difference MGS-BMS: 7.7, CI 95%: 3.94 to 11.46). MGS stent group had a higher percentage of successful angioplasty (cTFC ≤ 23: MGS 85% vs BMS 30%, 2p < 0.001). We had two cases of acute stent thrombosis (one for each group) at 30days follow up, but no clinical events at 6 months follow up.

CONCLUSIONS

In this exploratory study, MGS significantly improved microvascular reperfusion criteria compared with a BMS in primary PCI. However its safety and impact on clinical outcomes should be verified in larger randomized clinical trials.