Short- and long-term benefits of drug-eluting stents compared to bare metal stents even in treatment for large coronary arteries

Everolimus-Eluting Biodegradable Abluminal Coating Stent versus Durable Conformal Coating Stent: Termination of the Inflammatory Response Associated with Neointimal Healing in a Porcine Coronary Model

Objectives

We evaluated the effect of the different carrier systems on early vascular response through histological analysis and scanning electron microscopy using a porcine model.

Background

Although Synergy™ and Promus PREMIER™ share an identical stent material and drug elution (everolimus), they use different drug carrier systems: biodegradable abluminal coating polymer or durable conformal coating polymer, respectively. However, data regarding the impact of the different coating systems on vessel healing are currently limited.

Methods

Twelve Synergy™ and Promus PREMIER™ were implanted in 12 swine. Histopathological analysis of the stented segments was performed on the 2^nd and 14^th days after implantation. Morphometric analysis of the inflammation and intimal fibrin content was also performed.

Results

On the 2^nd day, neointimal thickness, percentage of neointimal area, and inflammatory and intimal fibrin content scores were not significantly different between the two groups. On the 14^th day, the inflammatory and intimal fibrin content scores were significantly lower in Synergy™ versus those observed in Promus PREMIER™. In Synergy™, smooth muscle cells were found and the neointimal layers were smooth. In contrast, inflammatory cells were observed surrounding the struts of Promus PREMIER™.

Conclusions

These results demonstrate that termination of reactive inflammation is accelerated after abluminal coating stent versus implantation of conformal coating stent.

Predictors of major adverse cardiac events following elective stenting of large coronary arteries

Objective

Diameter of the affected coronary artery is an important predictor of restenosis and need for revascularization. In the present study, we investigated the frequency and potential risk factors for major adverse cardiac events following elective percutaneous coronary intervention (PCI) and stenting of large coronary arteries.

Methods

We reviewed the data of elective candidates of PCI on a large coronary artery who presented to our center. Demographic, clinical, angiographic and follow-up data of the eligible patients were retrieved from our databank. The study characteristics were then compared between the patients with and without MACE in order to find out the probable risk factors for MACE in patients with large stent diameter.

Results

Data of 3043 patients who underwent single vessel elective PCI with a stent diameter of ≥3.5 mm was reviewed. During a median follow up period of 14 months, 64 (2.1%) patients had MACE. TVR was the most common type of MACE that was observed in 29 patients, while 5 patients had cardiac death. Higher serum levels of creatinine, history of cerebrovascular accident (CVA), and use of a drug eluting stent (DES) were significantly associated with MACE. In the multivariate model, history of CVA (odds ratio = 5.23, P = 0.030) and use of DES (odds ratio = 0.048, P = 0.011) were the independent predictors of MACE in patients underwent large coronary artery stenting.

Conclusion

This study showed that prior CVA and the use of BMS were the potential risk factors for MACE in patients who were stented on their large coronary arteries.

Initial and late efficacy of everolimus-eluting stents for small and non-small coronary lesions from evaluating delayed late loss study

The aim of the present study was to evaluate the long-term outcomes at 2 years in patients in whom everolimus-eluting stents (EESs) were implanted in small and non-small vessels. A small vessel is an important risk factor for restenosis with BMSs, even in the first generation DESs. The 690 patients with 690 lesions implanted with an EES were enrolled and divided into two groups by vessel reference diameter (RD): >2.5 mm for non-small vessels (Non-S-group) and ≤2.5 mm for small vessels (S-group). Two years later, the 365 patients with no restenosis at 8 months who underwent angiography were enrolled into the late catch-up study. At the initial 8-month follow-up, the rates of restenosis and target lesion revascularization (TLR) of both groups were not significantly different (restenosis 3.9 vs 6.5%, p = 0.17; TLR 3.9 vs 6.5%, p = 0.17). At the late 2-year follow-up, there were no significant differences in the late loss (0.36 ± 0.66 vs 0.34 ± 0.50 mm, p = 0.14), net gain (1.50 ± 0.75 vs 1.26 ± 0.60 mm, p = 0.39), late catch-up restenosis rate (5.1 vs 3.4%, p = 0.38), TLR (4.9 vs 2.7%, p = 0.40), and delayed late loss (0.14 ± 0.58 vs 0.15 ± 0.49 mm, p = 0.10) between both groups. There is no correlation between delayed late loss and RD in all patients(r = -0.009) and in AMI patients (r = -0.004). These results demonstrate that the initial and late catch-up restenosis rates of small coronary vessels with EES placement were excellent, the same as for non-small coronary vessels. We suggest that involvement of small coronary arteries may not be a risk factor for restenosis and results of stenting for small coronary arteries with EES placement were excellent.

Early endothelialization associated with a biolimus A9 bioresorbable polymer stent in a porcine coronary model

Although Nobori^®, with a bioresorbable polymer and biolimus A9 abluminal coating, has unique characteristics, few data exist regarding endothelialization early after implantation. Fifteen Nobori^® and 14 control bare-metal stents (S-stent™) were implanted in 12 pigs. Histopathology of stented segments, inflammation, and intimal fibrin content was evaluated on the 2nd and 14th day after implantation. On the 2nd day, endothelial cells were morphologically and immunohistologically confirmed on the surface of both stents, although some inflammatory cells might be involved. Stent surface endothelialization evaluated with a scanning electron microscope showed partial cellular coverage in both stents. On the 14th day, neointimal thickness and percentage of the neointimal area were significantly lower in Nobori^® than in S-stent™ (51.4 ± 4.5 vs. 76.4 ± 23.6 µm, p < 0.05 and 10.8 ± 2.6 vs. 14.1 ± 4.2%, p < 0.01). No significant differences were found in these parameters on the 2nd day (17.3 ± 14.9 vs. 26.7 ± 13.6 µm and 3.7 ± 3.0 vs. 6.7 ± 3.7%), in inflammatory and intimal fibrin content scores. These results demonstrate that endothelialization could occur early after Nobori^® implantation with similar inflammatory reaction to bare-metal stents, probably contributing to low frequency of in-stent thrombosis and restenosis.

The Impact of Admission Serum Creatinine Derived Estimated Glomerular Filtration Rate on Major Adverse Cardiac Events in ST-Segment Elevation Myocardial Infarction Patients Undergoing Primary Percutaneous Coronary Intervention

Background

The impact of Cockroft-Gault (C-G) derived estimated glomerular filtration rate (eGFR) on mortality and major adverse cardiac events (MACEs) in patients with ST-segment elevation myocardial infarction (STEMI) undergoing primary percutaneous coronary intervention (PCI) was assessed.

Methods

A total of 884 patients were classified into four categories according to admission creatine derived eGFR: < 60, 60 - < 90, 90 - < 120, and ≥ 120 mL/min/1.73 m².

Results

In-hospital and long-term MACEs were significantly higher in eGFR < 60 mL/min/1.73 m² subgroup (P < 0.001 and P = 0.028). Multivariate analysis demonstrated 7.78-fold (95% CI: 0.91 - 66.8) higher mortality risk in eGFR < 60 mL/min/1.73 m² subgroup.

Conclusion

As an easily applicable bedside method, C-G derived eGFR could be important for prediction of in-hospital and long-term mortality and MACE in STEMI patients undergoing primary PCI.