zotarolimus and Graft-Occlusion--Vascular

The optimal duration of dual antiplatelet therapy (DAPT) following the use of new generation drug-eluting stents is unknown.. The association between DAPT interruption and the rates of stent thrombosis (ST) and cardiac death/target-vessel myocardial infarction (CD/TVMI) in patients receiving a Resolute zotarolimus-eluting stent (R-ZES) was analysed in 4896 patients from the pooled RESOLUTE clinical programme. Daily acetylsalicylate (ASA) and a thienopyridine for 6-12 months were prescribed. A DAPT interruption was defined as any interruption of ASA and/or a thienopyridine of >1 day; long interruptions were >14 days. Three groups were analysed: no interruption, interruption during the first month, and >1-12 months. There were 1069 (21.83%) patients with a DAPT interruption and 3827 patients with no interruption. Among the 166 patients in the 1-month interruption group, 6 definite/probable ST events occurred (3.61%; all long DAPT interruptions), and among the 903 patients in the >1-12 months (60% occurred between 6 and 12 months) interruption group, 1 ST event occurred (0.11%; 2-day DAPT interruption). Among patients with no DAPT interruption, 32 ST events occurred (0.84%). Rates of CD/TVMI were 6.84% in the 1-month long interruption group, 1.41% in the >1-12 months long interruption group, and 4.08% in patients on continuous DAPT.. In a pooled population of patients receiving an R-ZES, DAPT interruptions within 1 month are associated with a high risk of adverse outcomes. Dual antiplatelet therapy interruptions between 1 and 12 months were associated with low rates of ST and adverse cardiac outcomes. Randomized clinical trials are needed to determine whether early temporary or permanent interruption of DAPT is truly safe. ClinicalTrials.gov Identifiers: NCT00617084; NCT00726453; NCT00752128; NCT00927940.

Topics: Aspirin; Blood Vessel Prosthesis; Clinical Trials as Topic; Clopidogrel; Coronary Thrombosis; Death, Sudden, Cardiac; Drug-Eluting Stents; Female; Fibrinolytic Agents; Graft Occlusion, Vascular; Humans; Male; Middle Aged; Multicenter Studies as Topic; Myocardial Infarction; Platelet Aggregation Inhibitors; Prospective Studies; Prosthesis Failure; Sirolimus; Ticlopidine; Time Factors; Treatment Outcome; Withholding Treatment

Compared to bare metal stent angioplasty, first-generation drug-eluting stents (DES) have markedly reduced the incidence of in-stent restenosis. However, given the increased concerns over late and very late stent thrombosis, newer-generation DES were developed. To date, these DES have virtually replaced the use of first-generation DES worldwide. In this review article, we carefully consider the pre-clinical and clinical trials that have been performed with currently available, european conformity-marked and Food and Drug Administration-approved new-generation Resolute(®) and Xience V(®) DES.

Topics: Angioplasty, Balloon, Coronary; Blood Vessel Prosthesis Implantation; Coronary Artery Disease; Drug-Eluting Stents; Everolimus; Graft Occlusion, Vascular; Humans; Immunosuppressive Agents; Sirolimus; Treatment Outcome

The prevalence of factors that are associated with an increased risk of stent thrombosis (ST), including smoking, diabetes mellitus, and small stent size, is different in women and men who underwent percutaneous coronary intervention. Thus, gender may potentially modify the relation between stent type and the incidence of ST during long-term follow-up. We explored the data of Patient Related Outcomes With Endeavor Versus Cypher stenting Trial (PROTECT) to evaluate this hypothesis. PROTECT randomized 2,061 women and 6,648 men who underwent percutaneous coronary intervention for various indications to Endeavor zotarolimus-eluting stenting (E-ZES) or Cypher sirolimus-eluting stenting (C-SES). Dual antiplatelet therapy was prescribed for at least 3 months. Data on study end points were collected until 5 years after randomization, including ST, death, and cardiovascular events. We analyzed end points and treatment effect (E-ZES vs C-SES) in relation to gender. Women were on average 4.7 years older (65.8 vs 61.1), had a higher prevalence of insulin-dependent diabetes mellitus, were less often smokers, and had a shorter total stent length than men. At discharge and throughout follow-up, a slightly lower fraction of women were using dual antiplatelet therapy. During 5-year follow-up, definite or probable ST was observed in 36 women (1.8%) and 152 men (2.4%; log-rank p = 0.15). E-ZES reduced the incidence of ST compared with C-SES in women (hazard ratio 0.58) and men (hazard ratio 0.61), with no evidence of heterogeneity (p = 0.89). In conclusion, in PROTECT, women and men had similar cumulative incidence of ST at 5 years after stent placement. The favorable effect of the study stent E-ZES over C-SES was not modified by gender.

Topics: Aged; Antibiotics, Antineoplastic; Coronary Artery Disease; Diabetes Mellitus; Drug-Eluting Stents; Female; Graft Occlusion, Vascular; Humans; Hypoglycemic Agents; Insulin; Male; Middle Aged; Percutaneous Coronary Intervention; Platelet Aggregation Inhibitors; Proportional Hazards Models; Sex Factors; Sirolimus; Thrombosis; Treatment Outcome

In acute myocardial infarction (MI), novel highly deliverable drug-eluting stents (DES) may be particularly valuable as their flexible stent designs might reduce device-induced traumas to culprit lesions. The aim of the study was to assess the safety and efficacy of percutaneous coronary interventions with 2 novel durable polymer-coated DES in patients with acute MI.. The prospective, randomized DUTCH PEERS (TWENTE II) multicenter trial compares Resolute Integrity and Promus Element stents in 1811 all-comer patients, of whom 817 (45.1%) were treated for ST-segment elevation MI or non-ST-segment elevation MI and the 2-year outcome is available in 99.9%. The primary clinical endpoint is target vessel failure (TVF), a composite of cardiac death, target vessel related MI, or target vessel revascularization.. Of all 817 patients treated for acute MI, 421 (51.5%) were treated with Resolute Integrity and 396 (48.5%) with Promus Element stents. At the 2-year follow-up, the rates of TVF (7.4% vs 6.1%; P = .45), target lesion revascularization (3.1% vs 2.8%; P = .79), and definite stent thrombosis (1.0% vs 0.5%; P = .69) were low for both stent groups. Consistent with these findings in all patients with acute MI, outcomes for the 2 DES were favorable and similar in both, with 370 patients with ST-segment elevation MI (TVF, 5.1% vs 4.9%; P = .81) and 447 patients with non-ST-segment elevation MI (TVF, 9.0% vs 7.5%; P = .56).. Resolute Integrity and Promus Element stents were both safe and efficacious in treating patients with acute MI. The present 2-year follow-up data underline the safety of using these devices in this particular clinical setting.

Topics: Aged; Antineoplastic Agents; Cardiovascular Diseases; Coronary Angiography; Drug-Eluting Stents; Everolimus; Female; Graft Occlusion, Vascular; Humans; Male; Middle Aged; Myocardial Revascularization; Netherlands; Non-ST Elevated Myocardial Infarction; Percutaneous Coronary Intervention; Sirolimus; ST Elevation Myocardial Infarction; Thrombosis

We compared 5-year clinical outcomes in diabetic and nondiabetic patients treated with Endeavor zotarolimus-eluting stents (ZESs; Endeavor Sprint, Medtronic, Santa Rosa, California) or Cypher sirolimus-eluting stents (SESs; Cordis, Johnson & Johnson, Warren, New Jersey) coronary implantation. We randomized 2,332 patients to either ZESs (n = 1,162, n = 169 diabetic patients) or SESs (n = 1,170, n = 168 diabetic patients) stratified according to presence or absence of diabetes mellitus. End points included major adverse cardiac event (MACE), a composite of cardiac death, myocardial infarction, target vessel revascularization (TVR), and definite stent thrombosis. Among diabetic patients, MACE occurred more frequently in patients treated with ZESs than SESs (48 [28.4%] vs 31 [18.5%]; odds ratio [OR] 1.75, 95% confidence interval [CI] 1.05 to 2.93, p = 0.032) because of a higher rate of TVR (32 [18.9%] vs 14 [8.3%]; OR 2.57, 95% CI 1.32 to 5.02, p = 0.006). Among nondiabetic patients, ZES and SES had similar MACE rates at 5-year follow-up but SES was associated with a significantly higher risk of definite stent thrombosis (10 [1.0%] vs 23 [2.3%]; OR 0.43, 95% CI 0.20 to 0.91, p = 0.028). Moreover, during the last 4 years, ZES had fewer MACE, TVR, and stent thrombosis events among nondiabetic patients. In conclusion, SES remains superior to ZES in patients with diabetes throughout the 5-year follow-up, however, among nondiabetic patients, SES demonstrated a highly dynamic performance with favorable initial results followed by a late catch-up that included an overall higher risk of stent thrombosis.

Topics: Blood Vessel Prosthesis Implantation; Case-Control Studies; Coronary Artery Disease; Coronary Restenosis; Diabetes Complications; Diabetes Mellitus; Drug-Eluting Stents; Female; Graft Occlusion, Vascular; Humans; Male; Myocardial Infarction; Prosthesis Failure; Reoperation; Sirolimus; Thrombosis; Treatment Outcome

Studies have indicated varying mortality risks with timing of stent thrombosis (ST), but few have been adequately powered with prospective late follow-up. PROTECT randomized 8,709 subjects to either Endeavor zotarolimus-eluting or Cypher sirolimus-eluting stents. PROTECT Continued Access enrolled 1,018 patients treated with Endeavor zotarolimus-eluting stents. Subjects completed at least 4 and 3 years of follow-up, respectively. ARC-defined definite and probable ST events were stratified by time from index procedure: early (≤30 days), late (>30 and ≤360 days), and very late (>360 days). Rates of death and myocardial infarction were analyzed by ST timing. Median follow-up was 4.1 years. There were 184 ST events (1.9%): 61 early, 27 late, and 96 very late. Patient and procedural characteristics were similar between timing groups. There was no difference in dual-antiplatelet therapy use at discharge (97%) or 1 year (84%). Cardiac death in patients with ST at 4 years occurred in 32.1% compared with 2.5% in patients without ST (p <0.001). Combined rates of cardiac death and myocardial infarction did not differ according to ST timing, yet early ST was more commonly associated with cardiac death at 4 years than later ST (50.8% for early vs 18.5% for late vs 24.0% for very late; p <0.001). The relation between ST timing and outcomes did not differ between stent types. In conclusion, in prospective data, cardiac death was more common after early ST than later ST. Although ST remains infrequent, continued efforts to determine how to reduce ST, particularly within the first 30 days, are warranted. (The PROTECT trial is registered with ClinicalTrials.gov, number NCT00476957.).

Topics: Aged; Cause of Death; Coronary Restenosis; Coronary Thrombosis; Drug-Eluting Stents; Female; Follow-Up Studies; Graft Occlusion, Vascular; Humans; Immunosuppressive Agents; Male; Middle Aged; Platelet Aggregation Inhibitors; Prospective Studies; Risk Factors; Sirolimus

To investigate the putative modifying effect of dual antiplatelet therapy (DAPT) use on the incidence of stent thrombosis at 3 years in patients randomized to Endeavor zotarolimus-eluting stent (E-ZES) or Cypher sirolimus-eluting stent (C-SES).. Of 8709 patients in PROTECT, 4357 were randomized to E-ZES and 4352 to C-SES. Aspirin was to be given indefinitely, and clopidogrel/ticlopidine for ≥ 3 months or up to 12 months after implantation. Main outcome measures were definite or probable stent thrombosis at 3 years. Multivariable Cox regression analysis was applied, with stent type, DAPT, and their interaction as the main outcome determinants. Dual antiplatelet therapy adherence remained the same in the E-ZES and C-SES groups (79.6% at 1 year, 32.8% at 2 years, and 21.6% at 3 years). We observed a statistically significant (P = 0.0052) heterogeneity in treatment effect of stent type in relation to DAPT. In the absence of DAPT, stent thrombosis was lower with E-ZES vs. C-SES (adjusted hazard ratio 0.38, 95% confidence interval 0.19, 0.75; P = 0.0056). In the presence of DAPT, no difference was found (1.18; 0.79, 1.77; P = 0.43).. A strong interaction was observed between drug-eluting stent type and DAPT use, most likely prompted by the vascular healing response induced by the implanted DES system. These results suggest that the incidence of stent thrombosis in DES trials should not be evaluated independently of DAPT use, and the optimal duration of DAPT will likely depend upon stent type (Clinicaltrials.gov number NCT00476957).

Topics: Aspirin; Blood Vessel Prosthesis; Clopidogrel; Coronary Restenosis; Coronary Thrombosis; Drug-Eluting Stents; Female; Fibrinolytic Agents; Graft Occlusion, Vascular; Humans; Male; Middle Aged; Platelet Aggregation Inhibitors; Prospective Studies; Prosthesis Failure; Sirolimus; Ticlopidine; Treatment Outcome

To compare the long-term clinical safety between two drug-eluting stents with different healing characteristics in the Patient Related Outcomes with Endeavour (E-ZES) vs. Cypher (C-SES) Stenting Trial (PROTECT). At 3 years, there was no difference in the primary outcome of definite or probable stent thrombosis or in the other main secondary clinical outcomes consisting of the composite of death or myocardial infarction (MI). Prespecified 4-year clinical follow-up was analysed.. Patient Related OuTcomes with Endeavour vs. Cypher Stenting Trial was a prospective, open-label randomized-controlled superiority trial powered to look at differences in long-term clinical safety, including stent thrombosis. Dual antiplatelet therapy (DAPT) was prescribed for ≥ 3 months and up to 12 months based on current guidelines. Patient Related OuTcomes with Endeavour vs. Cypher Stenting Trial enrolled 8791 patients undergoing elective or emergency PCI to E-ZES or C-SES. There was no difference in DAPT usage between the two groups up to 4 years. At 4-year follow-up, the primary outcome occurred in 1.6% of E-ZES vs. 2.6% of C-SES patients [HR 0.63 (95% CI 0.46-0.85), P = 0.003]. The composite of all-cause death or large MI occurred in 6.7% of E-ZES vs. 8.0% of C-SES-treated patients [HR 0.84 (95% CI 0.71-0.98), P = 0.024].. Drug-eluting coronary stents with different healing characteristics demonstrated different late safety profiles: after 4 years, compared with C-SES, E-ZES reduced the risk of stent thrombosis and the risk of the composite endpoints of death or MI. Appropriately powered large-scale trials with long-term follow-up are critical to determine clinical safety and efficacy of permanently implanted coronary stents. This trial is registered with ClinicalTrials.gov, number NCT00476957.

Topics: Coronary Restenosis; Coronary Thrombosis; Drug Therapy, Combination; Drug-Eluting Stents; Female; Graft Occlusion, Vascular; Humans; Immunosuppressive Agents; Male; Middle Aged; Myocardial Infarction; Platelet Aggregation Inhibitors; Prosthesis Failure; Sirolimus; Treatment Outcome

The purpose of this pre-specified analysis of the PROlonging Dual antiplatelet treatment after Grading stent-induced Intimal hyperplasia studY (PRODIGY) was to assess device-specific outcomes relative to different duration of dual antiplatelet therapy (DAPT) after Everolimus- (EES), Paclitaxel (PES), Zotarolimus- (ZES-S) eluting, or bare metal stents (BMS).. We randomized 2013 patients to BMS, ZES-S, PES, or EES implantation. At 30 days, each stent group underwent up to 6 or 24 months clopidogrel therapy. The primary endpoint, which was a composite of death, myocardial infarction, or cerebrovascular accident, did not differ in patients receiving BMS [HR: 0.89 (95% CI: 0.54-1.45)], PES [HR: 0.74 (95% CI: 0.43-1.25)], or EES [HR: 0.63 (95% CI: 0.33-1.21)] implantation across DAPT groups, whereas it was significantly higher in ZES-S patients undergoing long when compared with short-term DAPT therapy (HR: 2.85, P = 0.0018), with positive interaction testing (P-value = 0.004). At the 6-month landmark analysis, heterogeneity across stent types persisted for the primary study endpoint and other secondary clinical outcomes, whereas patients receiving PES showed a significantly higher rate of definite, probable and definite, probable, possible stent thrombosis in the short DAPT regimen. No association in absolute or relative terms was noted between stent potency in inhibiting intimal hyperplasia and greater vulnerability to shorter DAPT therapy.. Our study suggests that optimal duration of DAPT may be stent-specific and it does not support a clear association between stent potency and vulnerability to shorter DAPT therapy. Trial Registration clinicaltrials.gov Identifier: NCT00611286. http://clinicaltrials.gov/ct2/show/NCT00611286?term=prodigy&rank=2.

Topics: Aged; Clopidogrel; Coronary Restenosis; Coronary Vessels; Drug Administration Schedule; Drug Therapy, Combination; Drug-Eluting Stents; Everolimus; Female; Graft Occlusion, Vascular; Humans; Hyperplasia; Male; Myocardial Infarction; Platelet Aggregation Inhibitors; Sirolimus; Stents; Stroke; Ticlopidine; Tunica Intima

A 59-year-old man with critical claudication underwent left femoro-anterior bypass grafting, which was uneventful. The graft was tunneled medially across the knee, then anterior to the tibia. His symptoms recurred 1 year later and he was found to have critical stenosis of the vein graft just proximal to the anterior tibial arterial anastomosis. This was treated with scaffolded balloon angioplasty and implantation of a coronary, zotarolimus-eluting balloon-expandable stent, which was also uneventful. However, his claudication again recurred 1 year later. Diagnostic angiography revealed crush, deformation and restenosis of the balloon-expandable stent requiring surgical revision of the bypass graft.

Topics: Angioplasty, Balloon; Cardiovascular Agents; Computed Tomography Angiography; Critical Illness; Drug-Eluting Stents; Graft Occlusion, Vascular; Humans; Intermittent Claudication; Male; Middle Aged; Peripheral Arterial Disease; Prosthesis Design; Prosthesis Failure; Recurrence; Reoperation; Saphenous Vein; Sirolimus; Time Factors; Treatment Outcome; Ultrasonography, Doppler, Duplex; Vascular Grafting; Vascular Patency

The efficacy of second-generation drug-eluting stents (DES) in treating in-stent restenosis (ISR) compared to first-generation DES and non-DES treatment methods in real-world cohorts has not yet been adequately addressed. This research intends to examine optimum treatment of in-stent restenosis, considering first-generation DES, second-generation DES and non-DES treatment methods in a real-world cohort.. Retrospective analysis was performed on 114 patients treated for native-vessel BMS or DES ISR. Thirty-two were treated with a first-generation DES (81% sirolimus, 19% paclitaxel), 32 with a second-generation DES (72% everolimus, 28% zotarolimus) and 28 with non-DES methods (32% bare-metal stent, 39% balloon angioplasty, 29% cutting balloon). The composite primary endpoint was total adverse cardiac events, recurrent stable angina, unstable angina, myocardial infarction (MI), target vessel revascularisation (TVR) and cardiac death at minimum clinical follow-up of six months.. Primary endpoint rates were significantly higher in the non-DES and second-generation DES treatment groups than in first-generation DES (42.9%, 25.9%, 6.2%; p=0.004). Rates of MI and TVR were significantly higher in the non-DES treatment group, compared to first and second-generation DES (MI: 17.9%, 0%, 5.6%; p=0.018; TLR: 21.4%, 3.1%, 7.4%; p=0.041).. First-generation DES may be superior to second-generation DES and non-DES in treating BMS or DES ISR with regard to overall adverse cardiac events.

Topics: Aged; Angina, Stable; Drug-Eluting Stents; Everolimus; Female; Follow-Up Studies; Graft Occlusion, Vascular; Humans; Male; Middle Aged; Myocardial Infarction; Retrospective Studies; Sirolimus

Topics: Absorbable Implants; Angina Pectoris; Coronary Stenosis; Drug-Eluting Stents; Everolimus; Feasibility Studies; Female; Follow-Up Studies; Graft Occlusion, Vascular; Humans; Metals; Middle Aged; Percutaneous Coronary Intervention; Recurrence; Sirolimus; Tissue Scaffolds; Tomography, Optical Coherence; Tubulin Modulators

The combination of drugs with devices, where locally delivered drugs elute from the device, has demonstrated distinct advantages over therapies involving systemic or local drugs and devices administered separately. Drug-eluting stents are most notable. Ink jet technology offers unique advantages for the coating of very small medical devices with drugs and drug-coating combinations, especially in cases where the active pharmaceutical agent is very expensive to produce and wastage is to be minimized. For medical devices such as drug-containing stents, the advantages of ink-jet technology result from the controllable and reproducible nature of the droplets in the jet stream and the ability to direct the stream to exact locations on the device surfaces. Programmed target deliveries of 100 microg drug, a typical dose for a small stent, into cuvettes gave a standard deviation (SD) of dose of 0.6 microg. Jetting on coated, uncut stent tubes exhibited 100% capture efficiency with a 1.8 microg SD for a 137 microg dose. In preliminary studies, continuous jetting on stents can yield efficiencies up to 91% and coefficients of variation as low as 2%. These results indicate that ink-jet technology may provide significant improvement in drug loading efficiency over conventional coating methods.

Topics: Animals; Blood Vessel Prosthesis; Coated Materials, Biocompatible; Computer Peripherals; Drug Implants; Equipment Design; Equipment Failure Analysis; Fenofibrate; Graft Occlusion, Vascular; Humans; Hypolipidemic Agents; Immunosuppressive Agents; Printing; Sirolimus; Stents

To compare the efficacy of drug eluting stents (DES) compared with bypass surgery (CABG) with left internal mammary artery (LIMA) in patients with single vessel disease suffering from chronic stable angina.. There are a limited number of studies investigating this group of patients.. We included 257 consecutive patients with isolated lesion in the proximal segment of left anterior descending artery (LAD). All patients suffered from chronic stable angina or from stress-induced ischemia. Of 257 patients, 147 underwent DES implantation and 110 CABG with LIMA. All patients were followed-up clinically for major adverse cardiac events.. The baseline demographic and angiographic characteristics were similar between the two groups. In the DES group we used sirolimus-, paclitaxel-, and ABT-578-eluting stents. The mean duration of hospitalization after CABG was 7.86 +/- 3.84 days vs. 1.02 +/- 0.19 days after PCI (P < 0.01). The incidence of MACE was 2.72% in the DES and 2.72% in the surgical group during a mean follow-up period of 18.71 +/- 6.27 months for PCI and 18.70 +/- 7.31 months for CABG (P = 0.99). There was one cardiac related death in the DES group and two in the surgical group (P = 0.58). There were three reinterventions in the DES group versus none in the surgical group (P = 0.26). Recurrence of angina was observed in 4.08% of pts in the DES group versus 6.36% in the CABG group (P = 0.57).. The present study demonstrated that patients suffering from chronic stable angina with isolated lesion in the proximal segment of LAD have excellent long-term outcome in both surgical and DES treatment.

Topics: Angina Pectoris; Antineoplastic Agents, Phytogenic; Blood Vessel Prosthesis Implantation; Chronic Disease; Coated Materials, Biocompatible; Coronary Angiography; Coronary Artery Bypass; Female; Follow-Up Studies; Graft Occlusion, Vascular; Humans; Immunosuppressive Agents; Incidence; Male; Middle Aged; Paclitaxel; Sirolimus; Stents; Time Factors; Treatment Outcome

Stent-based delivery of the antiproliferative and immunosuppressive macrocyclic lactone sirolimus reduces neointimal formation and restenosis by cytostatic inhibition of vascular smooth muscle cell proliferation. The objective of this study was to determine the feasibility and efficacy of stent-based delivery of ABT-578, a structurally unique macrocyclic lactone. Stainless steel balloon-expandable stents were coated with thin layer of phosphorylcholine (PC) or PC with ABT-578 (10 microg/mm). Fifteen juvenile domestic pigs underwent placement of oversized bare metal (n = 15), PC (n = 8), and PC with ABT-578 (n = 9) stents in the coronary arteries. At 28 days, histology demonstrated similar mean injury scores for the control, PC-, and ABT-578-coated stents. The mean neointimal area (mm2) was significantly reduced for ABT-578 (1.70 +/- 0.47) as compared with PC (2.82 +/- 1.24) and control (2.89 +/- 1.91) stents (P < or = 0.05). The 40% reduction in neointimal area resulted in significantly less mean percent diameter stenosis for ABT-578 (19.4% +/- 4.0%) as compared with PC (30.3 +/- 12.1 %) and control (29.4% +/- 15.5%) stents (P < or = 0.03). Twelve of the 45 bare metal stent cross-sections (26.7%) exhibited a giant cell reaction, while none of the sections from the ABT-578-eluting stents had a giant cell reaction (P = 0.004). Stent-based delivery of ABT-578 via a PC surface coating inhibits neointimal formation at 28 days in the porcine coronary model. Further study is necessary to determine the dose-response and long-term effects ABT-578-eluting stents in the porcine coronary model.

Topics: Angioplasty, Balloon, Coronary; Animals; Coated Materials, Biocompatible; Coronary Vessels; Disease Models, Animal; Feasibility Studies; Graft Occlusion, Vascular; Immunosuppressive Agents; Phosphorylcholine; Sirolimus; Stents; Swine; Treatment Outcome; Tunica Intima