Evaluation of the dedicated Frontier™ coronary bifurcation stent: A matched pair analysis with drug-eluting and bare metal stents

Expansion of the Multi-Link Frontier™ coronary bifurcation stent: micro-computed tomographic assessment in human autopsy and porcine heart samples

BACKGROUND

Treatment of coronary bifurcation lesions remains challenging, beyond the introduction of drug eluting stents. Dedicated stent systems are available to improve the technical approach to the treatment of these lesions. However dedicated stent systems have so far not reduced the incidence of stent restenosis. The aim of this study was to assess the expansion of the Multi-Link (ML) Frontier™ stent in human and porcine coronary arteries to provide the cardiologist with useful in-vitro information for stent implantation and selection.

METHODOLOGY/PRINCIPAL FINDINGS

Nine ML Frontier™ stents were implanted in seven human autopsy heart samples with known coronary artery disease and five ML Frontier™ stents were implanted in five porcine hearts. Proximal, distal and side branch diameters (PD, DD, SBD, respectively), corresponding opening areas (PA, DA, SBA) and the mean stent length (L) were assessed by micro-computed tomography (micro-CT). PD and PA were significantly smaller in human autopsy heart samples than in porcine heart samples (3.54±0.47 mm vs. 4.04±0.22 mm, p = 0.048; 10.00±2.42 mm(2) vs. 12.84±1.38 mm(2), p = 0.034, respectively) and than those given by the manufacturer (3.54±0.47 mm vs. 4.03 mm, p = 0.014). L was smaller in human autopsy heart samples than in porcine heart samples, although data did not reach significance (16.66±1.30 mm vs. 17.30±0.51 mm, p = 0.32), and significantly smaller than that given by the manufacturer (16.66±1.30 mm vs. 18 mm, p = 0.015).

CONCLUSIONS/SIGNIFICANCE

Micro-CT is a feasible tool for exact surveying of dedicated stent systems and could make a contribution to the development of these devices. The proximal diameter and proximal area of the stent system were considerably smaller in human autopsy heart samples than in porcine heart samples and than those given by the manufacturer. Special consideration should be given to the stent deployment procedure (and to the follow-up) of dedicated stent systems, considering final intravascular ultrasound or optical coherence tomography to visualize (and if necessary optimize) stent expansion.

A novel 3-d reconstruction system for the assessment of bifurcation lesions treated by the mini-crush technique

BACKGROUND

Conventional two-dimensional angiography lacks the ability to properly image the true bifurcation geometry, and its percutaneous coronary intervention-induced changes in the clinical setting.

METHODS AND RESULTS

A novel three-dimensional reconstruction system was investigated by retrospectively analyzing 39 lesions in 35 consecutive patients with coronary bifurcation disease treated with the mini-crush technique. At baseline, significant correlations were proved between two- and three-dimensional systems in terms of either reference vessel diameter (R(2)= 0.68 and 0.29 for main and side branches, respectively), minimum lumen diameter (R(2)= 0.73 and 0.36), stenosis diameter (R(2)= 0.69 and 0.29), and lesion length (R(2)= 0.48 and 0.58). These results were consistent with those observed after the procedure and at 8-month follow-up. Lesion length was significantly longer with the three-dimensional compared to the two-dimensional system for both main and side branches (P < 0.001, and P = 0.007, respectively).

CONCLUSIONS

The three-dimensional quantitative reconstruction system may provide accurate evaluation of the complex curvilinear structure of bifurcation lesions when using a double stent technique.

Azithromycin does not prevent six-month myointimal proliferation but attenuates the transient systemic inflammation occurring after coronary stenting

OBJECTIVES

Stent implantation produces a systemic increase of inflammatory markers that correlates with Chlamydophila pneumoniae infection in atherosclerotic plaque. We performed a clinical intervention study to investigate the effect of antibiotic treatment on 6-month follow-up angiographic minimal luminal diameter after stenting.

METHODS

Ninety patients were randomly assigned to oral azithromycin or placebo in a double-blinded and randomized fashion. Medication was initiated 2 weeks before a pre-scheduled stenting procedure and maintained 12 weeks thereafter. Angiographic outcomes were evaluated by a six-month follow-up angiography and laboratorial parameters were accessed by blood sampling 2 weeks before stenting, within the first 24 h after procedure and additional samples after four weeks and 6 months.

RESULTS

Minimal luminal diameter (1.76 +/- 0.56 mm Vs. 1.70 +/- 0.86 mm; P = 0.7), restenosis rate, diameter stenosis, late loss, and binary restenosis rates were comparable in placebo and azithromycin group in the 6 months follow-up. Serum levels of C-reactive protein presented a three fold significant increase in the control group one day after stenting but did not change in the azithromycin group (8.5 [3.0;16.4] Vs. 2.9 [1.7;6.6]-median [25;75 percentile] P < 0.01).

CONCLUSIONS

Azithromycin does not improve late angiographic outcomes but attenuates the elevation of C-reactive protein levels after stenting, indicating an anti-inflammatory effect.