Intracoronary optical coherence tomography and histology of overlapping everolimus-eluting bioresorbable vascular scaffolds in a porcine coronary artery model: the potential implications for clinical practice.

OBJECTIVES: This study sought to assess the vascular response of overlapping Absorb stents compared with overlapping newer-generation everolimus-eluting metallic platform stents (Xience V [XV]) in a porcine coronary artery model. BACKGROUND: The everolimus-eluting bioresorbable vascular scaffold (Absorb) is a novel approach to treating coronary lesions. A persistent inflammatory response, fibrin deposition, and delayed endothelialization have been reported with overlapping first-generation drug-eluting stents. METHODS: Forty-one overlapping Absorb and overlapping Xience V (XV) devices (3.0 × 12 mm) were implanted in the main coronary arteries of 17 nonatherosclerotic pigs with 10% overstretch. Implanted coronary arteries were evaluated by optical coherence tomography (OCT) at 28 days (Absorb n = 11, XV n = 7) and 90 days (Absorb n = 11, XV n = 8), with immediate histological evaluation following euthanasia at the same time points. One animal from each time point was evaluated with scanning electron microscopy alone. A total of 1,407 cross sections were analyzed by OCT and 148 cross sections analyzed histologically. RESULTS: At 28 days in the overlap, OCT analyses indicated 80.1% of Absorb struts and 99.4% of XV struts to be covered (p < 0.0001), corresponding to histological observations of struts with cellular coverage of 75.4% and 99.6%, respectively (p < 0.001). Uncovered struts were almost exclusively related to the presence of "stacked" Absorb struts, that is, with a direct overlay configuration. At 90 days, overlapping Absorb and overlapping XV struts demonstrated >99% strut coverage by OCT and histology, with no evidence of a significant inflammatory process, and comparable % volume obstructions. CONCLUSIONS: In porcine coronary arteries implanted with overlapping Absorb or overlapping XV struts, strut coverage is delayed at 28 days in overlapping Absorb, dependent on the overlay configuration of the thicker Absorb struts. At 90 days, both overlapping Absorb and overlapping XV have comparable strut coverage. The implications of increased strut thickness may have important clinical and design considerations for bioresorbable platforms.

The prognostic utility of the SYNTAX score on 1-year outcomes after revascularization with zotarolimus- and everolimus-eluting stents: a substudy of the RESOLUTE All Comers Trial.

OBJECTIVES: This study assessed the ability of the SYNTAX score (SXscore) to stratify risk in patients treated with percutaneous coronary intervention (PCI) using zotarolimus-eluting or everolimus-eluting stents. BACKGROUND: The SXscore can identify patients treated with PCI who are at highest risk of adverse events. METHODS: The SXscore was calculated prospectively in 2,033 of the 2,292 patients enrolled in the RESOLUTE All Comers study (RESOLUTE III All Comers Trial: A Randomized Comparison of a Zotarolimus-Eluting Stent With an Everolimus-Eluting Stent for Percutaneous Coronary Intervention). Clinical outcomes in terms of a patient-oriented composite endpoint (POCE) of all-cause death, myocardial infarction (MI), and repeat revascularization; the individual components of POCE; target lesion failure (TLF) (a composite of cardiac death, target-vessel MI, and clinically driven target lesion revascularization); and stent thrombosis were subsequently stratified according to SXscore tertiles: SXscore(LOW) ≤ 9 (n = 698), 9 17 (n = 659). RESULTS: At 12-month follow-up, rates of POCE, MI, repeat revascularization, TLF, and the composite of death/MI were all significantly higher in patients in the highest SXscore tercile. Rates of stent thrombosis were all highest in the SXscore(HIGH) tertile (p > 0.05). After multivariate adjustment, the SXscore was identified as an independent predictor of POCE, MI, repeat revascularization, and TLF (p < 0.05 for all). At 12-month follow-up, the SXscore, ACEF score, and Clinical SXscore had C-statistics of 0.57, 0.78, and 0.67, respectively, for mortality and of 0.62, 0.56, 0.63, respectively, for POCE. No significant between-stent differences were observed for TLF or POCE in any of the SXscore tertiles. CONCLUSIONS: The SYNTAX score is able to stratify risk amongst an all-comers population treated with PCI with second-generation drug-eluting stents (DES); however, improvements can be made with the inclusion of clinical variables. (RESOLUTE III All Comers Trial: A Randomized Comparison of a Zotarolimus-Eluting Stent With an Everolimus-Eluting Stent for Percutaneous Coronary Intervention; NCT00617084).

Haemodynamic effects, safety, and tolerability of haemoglobin-based oxygen carrier-201 in patients undergoing PCI for CAD.

AIMS: Haemoglobin based oxygen carriers (HBOCs) are considered in the treatment of patients with acute coronary syndromes (ACS) undergoing percutaneous coronary intervention (PCI). In light of their potential vasopressor and colloidal properties, their effect on coronary physiology, safety and tolerability needs to be established. METHODS AND RESULTS: In this phase II pilot trial, 45 patients were randomly assigned, (1:1:1) to double blind treatment with a 30 minute intravenous (IV) infusion of either 15 or 30 g of HBOC-201, compared to an equivalent volume of non-oxygen carrier colloid control. Systemic, pulmonary, and coronary haemodynamics were studied during this infusion period. IV HBOC-201 administration produced an increase in systolic blood pressure (SBP), pulmonary capillary wedge pressure and calculated systemic vascular resistance (SVR) and a concomitant decrease in cardiac output (CO); there was a decrease in mixed venous saturation (SVO2) following IV HBOC-201. The left ventricular stroke work index (LVSWI) was not altered by HBOC-201 treatment. Of note, no coronary vasoconstriction was observed, nor were there significant changes in resting average peak velocity (APV), coronary-artery diameter, volumetric coronary blood flow, or coronary vascular resistance. The percentage of patients with adverse events did not differ between the HBOC-201 treated and control groups (76% vs. 63%, respectively, P=0.49). Seven serious adverse events (SAE) occurred in six patients in the treatment group and two in two patients in the control group. Only one SAE (hypertension) was judged HBOC-201 related. Patients in both the HBOC-201 and control group had a similar incidence of increased liver alanine transaminase (31% vs 31%, respectively, NS); 10% of the patients in the HBOC-201 group had increases greater than three times the upper limit of normal. Differential increases were noticed in some inflammatory markers (IL-6, CRP) 18-24 hours after infusion between the HBOC-201 arms and the control group. CONCLUSION: No compromise in the coronary blood flow or LVSWI was observed despite HBOC-201's known vasoactive effects. One SAE was adjudicated as "drug related" and fully resolved. The clinical relevance of the differential rise in certain biochemical markers and the adverse effects of plasma haemoglobin in the context of ACS needs further investigation.

'Fused-Gold' vs. 'Bare' stainless steel NIRflex stents of the same geometric design in diseased native coronary arteries. Long-term results from the NIR TOP Study.

OBJECTIVES: We evaluated the long-term clinical and angiographic results of 'fused-gold' (NIRFlex Royal) and 'bare' (NIRFlex) stainless steel stents in patients undergoing percutaneous coronary intervention (PCI). BACKGROUND: Recent studies have shown high clinical and angiographic restenosis rates following the intracoronary implantation of 'gold-coated' stainless steel stents. The new 'fused-gold' stent, with improved surface characteristics and flexibility, was developed to improve procedural and long-term results, while maintaining enhanced radiopacity. METHODS: A total of 305 patients (358 lesions) with symptomatic native coronary artery disease (CAD) undergoing native vessel PCI were randomised to receive a 'fused-gold' (n=147) or 'bare' (n=158) stent. Primary endpoint was minimal luminal diameter (MLD) at 6 months angiographic follow-up. Secondary endpoints included technical and procedural success, major adverse cardiac events (MACE), target vessel failure (TVF), angiographic binary restenosis rates, and additional angiographic comparisons. RESULTS: There were no major differences in the baseline angiographic variables or patient characteristics between the two groups, however there was a trend towards a higher risk in the 'fused-gold' stent group. Clinical and angiographic follow-up was 100% and 87% respectively. MLD at 6 months follow-up was smaller in the 'fused-gold' stent group compared to the 'bare' stent group (1.61+/-0.65 vs. 1.81+/-0.60 mm, respectively); Therefore, the null hypothesis of non-inferiority cannot be rejected (p=0.49); equivalency cannot be claimed for the two stent types. The 'fused-gold' stents were also associated with a higher angiographic binary and clinical restenosis rates (33 vs. 18%; p=0.002 & 26.9 vs. 20.3%; p<0.001, respectively). CONCLUSION: The 'bare' NIRflex stent was associated with excellent long-term clinical and angiographic results. Taking into account the equivalence margin, the null hypothesis of non-equivalence between the 'fused-gold' NIRflex Royal stent and the 'bare' NIRflex stent cannot be rejected (p=0.49), so equivalence cannot be claimed for the two stent types.