Acute and long-term outcomes of stenting in coronary vessel > 3.0 mm, 3.0-2.5 mm, and < 2.5 mm

Clinical Outcome after Everolimus-Eluting Stent Implantation for Small Vessel Coronary Artery Disease: XIENCE Asia Small Vessel Study

There are limited data on outcomes after implantation of everolimus-eluting stents (EES) in East Asian patients with small vessel coronary lesions. A total of 1,600 patients treated with XIENCE EES (Abbott Vascular, CA, USA) were divided into the small vessel group treated with one ≤2.5 mm stent (n=119) and the non-small vessel group treated with one ≥2.75 mm stent (n=933). The primary end point was a patient-oriented composite outcome (POCO), a composite of all-cause death, myocardial infarction (MI), and any repeat revascularization at 12 months. The key secondary end point was a device-oriented composite outcome (DOCO), a composite of cardiovascular death, target-vessel MI, and target lesion revascularization at 12 months. The small vessel group was more often female, hypertensive, less likely to present with ST-elevation MI, and more often treated for the left circumflex artery, whereas the non-small vessel group more often had type B2/C lesions, underwent intravascular ultrasound, and received unfractionated heparin. In the propensity matched cohort, the mean stent diameter was 2.5±0.0 mm and 3.1±0.4 mm in the small and non-small vessel groups, respectively. Propensity-adjusted POCO at 12 months was 6.0% in the small vessel group and 4.3% in the non-small vessel group (p=0.558). There was no significant difference in DOCO at 12 months (small vessel group: 4.3% and non-small vessel group: 1.7%, p=0.270). Outcomes of XIENCE EES for small vessel disease were comparable to those for non-small vessel disease at 12-month clinical follow-up in real-world Korean patients.

One-year clinical outcomes of patients implanted with a Resolute Onyx™ zotarolimus-eluting stent

Objective

To evaluate the 1-year clinical outcomes of patients who received the Resolute Onyx™ stent.

Methods

This was a single-centre, retrospective registry analysis that reviewed the clinical data from all patients who were implanted with a Resolute Onyx™ stent between March 2015 and February 2016. Clinical follow-up was performed at 1 year post-implantation.

Results

A total of 252 patients received a Resolute Onyx™ stent and two patients were lost to follow-up. The mean age of the cohort was 66.9 years and 113 (45.2%) had diabetes mellitus. Thirty-eight patients (15.2%) had left main disease and 73 (29.2%) had three-vessel disease. A total of 175 patients (70.0%) had small vessel disease (<2.75 mm) and 210 (84.0%) had long lesions (>20 mm). The 1-year target lesion failure was 4.4% (11 of 250), cardiovascular death occurred in eight patients (3.2%), ischaemia-driven target lesion revascularization was undertaken in five patients (2.0%) and stent thrombosis occurred in one patient (0.4%).

Conclusion

The Resolute Onyx™ stent showed a favourable 1-year clinical performance in a real-world population.

Small-vessel treatment with contemporary newer-generation drug-eluting coronary stents in all-comers: Insights from 2-year DUTCH PEERS (TWENTE II) randomized trial

BACKGROUND

Treatment of lesions in small vessels was associated with worse clinical outcome, and various definitions of "small vessels" have been used. Data with novel drug-eluting stents are scarce.

METHODS

To compare the outcome of patients with vs without small-vessel treatment, we assessed 2-year follow-up data of the DUTCH PEERS randomized trial (ClinicalTrials.gov: NCT01331707), in which 1,811 all-comers were treated with contemporary zotarolimus-eluting (Resolute Integrity) or everolimus-eluting (Promus Element) stents. Primary end point was target lesion failure (TLF), a composite of cardiac death, target vessel myocardial infarction, and target lesion revascularization.

RESULTS

The rates of TLF (9.5% vs 5.4%; P log rank = .001) and 2 individual components thereof-target vessel myocardial infarction (3.1% vs 1.3%; P log rank = .006) and target lesion revascularization (4.8% vs 2.8%; P log rank = .02)-were higher among 798 (44.1%) patients treated in at least one small vessel (<2.50 mm by quantitative coronary angiography). Multivariate analysis with propensity score adjustment demonstrated that treatment of small-vessel lesions independently predicted TLF at 2-year follow-up (hazard ratio 1.60, 95% CI 1.09-2.34). Patients with the smallest target vessel being <2.25 mm had TLF rates similar to patients with smallest target vessels of 2.25 to <2.50 mm; however, patients treated in vessels no smaller than 2.50 to <3.00 mm and patients treated in vessels ≥3.00 mm had lower TLF rates (9.3%, 9.8%, 5.0%, and 5.8%, respectively; P log rank = .009).

CONCLUSION

Patients treated with novel drug-eluting stents in small-vessel lesions had higher adverse event rates than did patients who had no small-vessel treatment. Our data suggest that with current stents, a vessel diameter <2.50 mm is a suitable threshold to identify small target vessels.

Comparison of Long-Term Outcomes in Real-World Patients Between Resolute Zotarilumus-Eluting and Paclitaxel-Eluting Stents in Small Vessel

OBJECTIVE

To compare the long-term clinical outcomes between Resolute zotarolimus-eluting stent (R-ZES) and paclitaxel-eluting stent (PES) in patients with small coronary artery disease.

BACKGROUND

Patients with a small vessel diameter are independently associated with increased risk of adverse cardiac events after drug-eluting stent implantation.

METHODS

A cohort of 265 patients treated with R-ZES (185 patients with 211 lesions) or PES (80 patients with 100 lesions) in small vessel (≤2.5 mm) lesions were retrospectively analyzed. The primary end point of the study was the composite of major adverse cardiac events. The secondary end points included target lesion revascularization (TLR), target vessel revascularization (TVR), and stent thrombosis at 3 years.

RESULTS

The baseline characteristics were similar between the 2 groups. In the R-ZES group, the mean stent diameter was smaller and the total stent length per lesion was longer. Major adverse cardiac events occurred in 8 (10%) patients who had received PES and in 7 (3.8%) patients who had received R-ZES (P = .07). The rates of 3-year TLR (2.2% vs 2.5%; P = 1.00) and TVR (5.4% vs 10.0%; P = .17) showed no statistically significant difference between the R-ZES and PES groups. The rate of stent thrombosis was 0.5% in the R-ZES group and 2.5% in the PES group (P = .21).

CONCLUSION

The rates of major adverse cardiac events and cardiac death were similar in the R-ZES-treated group compared with the PES-treated group.

Long-term safety of drug-eluting stents

Stent implantation in coronary stenosis has revolutionized the treatment of coronary artery disease. The introduction of antirestenotic drug coatings further improved their efficacy in reducing target vessel revascularizations. With increasing use of drug-eluting stents (DES), stent thrombosis (ST) rose as potentially fatal major complication. Initially, the incidence of ST late after stent implantation seemed to be similar for DES and bare metal stents until several studies proved otherwise in first-generation DES. Since then, the design and components of DES have been changed and new polymers, drugs and different combinations of platelet inhibitors have been introduced to further improve the safety of DES. In this review, the authors focus on the relationship between DES, lesion anatomy, implantation technique and pharmacology to avoid the occurrence of ST. Furthermore, the relationship between dual antiplatelet therapy, bleeding rate and its significant impact on patient outcome is discussed. Finally, some promising future concepts are highlighted.

One-year outcome of small-vessel disease treated with sirolimus-eluting stents: a subgroup analysis of the e-SELECT registry

OBJECTIVES

To investigate the characteristics and one-year outcomes following sirolimus-eluting CYPHER Select Plus stent (SES) implantation in small (SmVD) and non-small vessel disease (NSmVD) in the international e-SELECT registry.

BACKGROUND

Large-scale registry data are lacking on DES outcomes in SmVD treatment.

METHODS

There were 4,700 SmVD (at least one vessel with estimated reference vessel diameter [RVD] < 2.5 mm, excluding 283 patients with unknown RVD vessels) and 10,139 NSmVD only patients.

RESULTS

The SmVD population was older, with more women, diabetics, and vessels treated, higher mean Charlson Comorbidity Index score (CCI), shorter lesions, and less STEMI presentation. The 1-year stent thrombosis (ST) rate (primary end-point), was significantly higher (1.3% vs. 0.7%) in SmVD versus NSmVD, mainly driven by early events. One-year major adverse cardiac event (MACE), myocardial infarction (MI), and clinically indicated target-lesion revascularization (TLR) rates were significantly higher in SmVD although death and major bleeding rates were similar in both groups. Complication rates were similar between pure (3,188 patients; only RVD < 2.5 mm) and mixed (1,795 patients; some RVD < 2.5 mm or unknown RVD) SmVD. Multivariate predictors for 1-year MACE in SmVD included saphenous vein graft or bifurcation lesions, major bleeding, any antiplatelet therapy discontinuation within 1 month, age, number of stents implanted, CCI, acute coronary syndrome, and insulin-dependent diabetes mellitus.

CONCLUSION

SES implantation for SmVD occurs more frequently in women, diabetics, and those with multivessel disease and comorbidities. One-year ST, MACE, MI, and clinically indicated TLR rates are higher, although low overall, in SmVD or mixed SmVD patients while death rates are similar to NSmVD.

The XIENCE nano everolimus eluting coronary stent system for the treatment of small coronary arteries: the SPIRIT Small Vessel trial

OBJECTIVES

The SPIRIT Small Vessel (SV) was designed to evaluate the safety and effectiveness of the 2.25-mm XIENCE V everolimus eluting coronary stent system (EECSS), known as the XIENCE nano EECSS, in subjects with SVs and ischemic heart disease.

BACKGROUND

The core sizes of XIENCE V EECSS are associated with low rates of restenosis and thrombosis in the general population, but the XIENCE nano EECSS has not been tested in the United States.

METHODS

This prospective, single-arm, open-label study was conducted at 33 centers and in 150 patients in the United States. The primary endpoint was the target lesion failure (TLF) rate at 1 year, required to meet the prespecified performance goal (PG) of 20.4%, derived from historical data.

RESULTS

The mean patient age was 63 years, 38% were women, 39.2% were diabetic, 49.3% had multivessel disease, and the reference vessel diameter was 2.13 ± 0.23 mm. The 1-year TLF rate was 8.1% in with an upper limit of the one-sided 95% confidence interval of 13.0%, which met the PG of 20.4% (P < 0.0001). At 1 year, the rate of cardiac death was 1.5%, the target vessel myocardial infarction rate was 1.5%, and clinically indicated target lesion revascularization rate was 5.1%. The 8-month angiographic in-stent late loss was 0.2 ± 0.4 mm, respectively. The 1-year academic research consortium defined definite/probable stent thrombosis rate was 1.5%.

CONCLUSIONS

Based on the 1-year clinical and 8-month angiographic SPIRIT SV data, the XIENCE nano EECSS is considered safe and effective in the treatment of SVs.

Serial intravascular ultrasonic study of outcomes of coronary culprit lesions with plaque rupture following bare metal stent implantation in patients with angina pectoris

Coronary culprit lesions with plaque rupture (PR) have been treated with different coronary interventions. However, it is unknown whether the presence of PR affects the restenotic process after coronary intervention. One hundred forty-two patients undergoing coronary bare metal stent implantation were enrolled in the present retrospective analysis. Case selection was based on availability of intravascular ultrasound (IVUS) and quantitative coronary angiographic examinations at baseline (before and after intervention) and at follow-up. Serial comparative analyses included qualitative and quantitative features of the culprit lesion and reference segments. PR was defined as an intraplaque cavity in communication with the lumen in the presence of a residual, disrupted cap. Patients were categorized according to the presence/absence of PR. Pre-interventional IVUS detected PR in 54 patients (38%). Baseline patient demographics were similar between the +PR and -PR groups. Quantitative IVUS analysis showed higher rates of positive remodeling and larger vessel and plaque areas in the +PR compared with -PR lesions (p <0.001 for all). At follow-up (7.2 +/- 2.6 months), no statistically significant difference was observed between the 2 groups in quantitative coronary angiographic or IVUS measurements. In conclusion, culprit lesions with PR exhibited larger plaque mass and higher rates of positive remodeling at preintervention IVUS examination. However, when treated with bare metal stents, the absence/presence of preintervention PR was not found to affect the rate or severity of in-stent restenosis in these culprit lesions.

Sirolimus-eluting coronary stents in small vessels

BACKGROUND

This prospective multicenter study compared angiographic in-lesion late lumen loss in de novo native coronary artery lesions (vessel diameter range 2.25-2.75 mm, length range > or = 15 to < or = 30 mm) 8 months after the implantation of a sirolimus-eluting stent with that of similar vessels with the same drug-eluting stent or a bare stent of the SIRIUS study (historical controls).

METHODS AND RESULTS

One hundred one patients (study group) were matched and compared with 323 patients receiving the bare stent (bare control group) and with 350 receiving the Cypher stent (Cypher control group) in the SIRIUS trial. Mean in-lesion late loss in the study group was lower than that in the bare control group (0.20 versus 0.76 mm, P < .0001) and not inferior to that in the Cypher control group (0.27 mm, P = .3). Adverse event rates (death and myocardial infarction) were similar between groups. At 8 months, target lesion revascularization rates were 0% in the study group, 13.2% in the bare control group (P < .001), and 4.6% in the Cypher control group (P = .03).

CONCLUSIONS

The Cypher Bx Velocity stent was confirmed to be superior to the bare Bx Velocity stent in small coronary vessels in terms of in-lesion late loss 8 months after implantation.

Endoluminal phototherapy for prevention of restenosis: preliminary results at 6-month follow-up

OBJECTIVE

The objective of this observational study was to investigate safety and efficacy of laser phototherapy (LPh) in prevention of restenosis after percutaneous coronary intervention (PCI).

BACKGROUND DATA

Laser irradiation is known to cause a limitation of the local inflammatory cascade and a stimulation of proliferation of specific cells. Based on the results of previous experiments proving the beneficial effects of laser light on the activity of vascular and inflammatory cells, we attempted to use these properties to prevent restenosis.

METHODS

Laser phototherapy was performed in 41 patients after stent implantation or balloon angioplasty. Illumination power of 100 mW and energy dose equal to 9 J/cm(2) was used. Patients were monitored for major adverse cardiac events (MACE) after 30 days and 6 months. At 6 months, angiography as a control was performed to assess the influence of LPh on restenosis rate.

RESULTS

Angiographic follow-up (n = 30) revealed restenosis in 9% and 25% of patients after stent implantation and balloon angioplasty, respectively. The MACE rate was 4.5% and 12.5% in stent and balloon-treated patients, respectively.

CONCLUSIONS

Laser phototherapy gives very promising results in restenosis prevention, especially after stent implantation. The treatment method is safe, with a low rate of MACE in follow-up.

A Cost-Effectiveness Analysis of a Hypothetical Catheter-Based Strategy for the Detection and Treatment of Vulnerable Coronary Plaques with Drug-Eluting Stents

AIM

Extensive efforts are underway to develop methods for the detection and treatment of vulnerable/high-risk coronary artery plaques. We utilized decision analysis to evaluate the hypothetical clinical benefits and cost-effectiveness of a catheter-based strategy.

METHODS AND RESULTS

Currently, stenotic coronary plaques are treated without regard to vulnerability. In a new strategy, vulnerable coronary plaques are detected with a catheter-based test and treated with a drug-eluting stent, regardless of degree of stenosis. A Markov-decision model was developed to compare the new strategy with current practice. Monte Carlo simulations were performed from a societal perspective, costs were converted to year 2003 U.S. dollars, and future costs and outcomes were discounted at 3%. Sensitivity analyses were performed to evaluate the effect of assumptions on variables such as the prevalence of vulnerable plaques and treatment effect. In 60-year-old male patients with coronary stenoses the new strategy would be less expensive and more effective than current practice (37,045 dollars vs 38,257 dollars and 10.23 vs 9.86 quality-adjusted life years (QALYs), respectively). The benefits of the new strategy were robust in sensitivity analyses (e.g., if the prevalence of vulnerable plaques in this patient group was 50% or more and the sensitivity and specificity of the new test were at least 0.80).

CONCLUSION

In selected patients with coronary artery stenosis, the detection of vulnerable plaques with a catheter-based test followed by their treatment with a drug-eluting stent could be a less expensive and more effective strategy than current practice. If applied to 1 million such patients in the United States undergoing catheterization, the new strategy would add 370,000 QALYs and save 1.2 billion dollars per year.

Elective stenting for symptomatic middle cerebral artery stenosis presenting as transient ischaemic deficits or stroke attacks: short term arteriographical and clinical outcome

BACKGROUND

Although stent assisted angioplasty is an effective treatment for coronary and peripheral arterial disease, its efficacy in intracranial arteriosclerotic disease has not been verified.

OBJECTIVES

To assess the radiographic and clinical outcome of stent assisted angioplasty for symptomatic middle cerebral artery (MCA) stenosis.

METHODS

We attempted stent assisted angioplasty in 14 patients with symptomatic high grade stenosis (>60%) on the proximal portion of the MCA, who had experienced either recurrent transient ischaemic attacks (TIAs) resistant to medical therapy or one or more stroke attacks. Patient records were analysed for angiographic characteristics, degree of stenosis, pre-procedural regimen of anti-platelet and/or anti-coagulation agents, use of devices, procedure related complications, pre-operative and post-operative single photon emission computed tomography (SPECT) findings, and clinical and radiographic outcomes.

RESULTS

Stent assisted angioplasty was successfully performed in 8 of 14 patients without any serious complications and unsuccessful in 2 of 14 patients due to the tortuous curve of the internal carotid artery siphon. Four patients had complications. Two patients had an arterial rupture; one patient was rescued by an additional stent and balloon tamponade, the other patient died. Complications in the other two patients included thrombotic occlusion and distal thrombosis. Residual stenosis was less than 50% in diameter in all the patients. All eight patients who underwent follow up cerebral angiography had no restenosis. Follow up SPECT showed improved perfusion in the affected MCA territory in all the tested patients with TIA and in one of three stroke patients. Using the modified Rankin Scale at follow up, four of five TIA patients and five of six stroke patients were assessed as functionally improved or having a stable clinical status.

CONCLUSION

Although the re-stenosis rate in stent assisted angioplasty seems to be better than in primary balloon angioplasty as reported previously, the complication rate is still high. Elective stenting is an alternative therapeutic method for the prevention of secondary ischaemic stroke in stroke patients with MCA stenosis, and seems to be a potentially effective but also hazardous therapeutic technique in patients with recurrent TIAs. This study indicates the need for randomised control trial data of this intervention. Additionally, long term follow up data and additional clinical experience are required to assess the durability of this procedure.

Relation of final lumen dimensions in saphenous vein grafts after stent implantation to outcome

Larger final lumen dimensions after percutaneous coronary interventions in native coronary arteries lead to lower restenosis rates. We sought to determine the impact of stent expansion, as assessed by intravascular ultrasound, on clinical results of stent implantation in saphenous vein grafts (SVGs). We identified 226 consecutive patients who underwent intravascular ultrasound-guided stenting of 234 de novo SVG lesions. Patients were divided into 2 groups based on the final stent cross-sectional area (CSA): group I (stent CSA <100% of the reference lumen CSA, n = 176 patients, 182 lesions) and group II (stent CSA >/=100% of the reference lumen CSA, n = 50 patients, 52 lesions). Baseline patient characteristics were similar between the 2 groups with the exception of smaller lesions in group II. More aggressive stent expansion (group II) was associated with (1) increased rates of in-hospital non-Q-wave myocardial infarction (29% vs 17%, p = 0.05), (2) any myocardial infarction (26% vs 8%, p = 0.003) at 1-year follow-up, and (3) no improvement in target vessel revascularization at 1 year (31% vs 26%, p = 0.3). Aggressive stent expansion in SVG lesions resulted in higher myocardial infarction rates and, unlike native arteries, no improvement in target vessel revascularization rate at 1 year. A less aggressive stent implantation strategy in SVGs than in native coronary lesions appears prudent.

Angiographic outcome in multivessel disease (GABI II study) using new coronary device interventions and comparison with GABI I trial results

Percutaneous coronary interventions using stents were investigated in patients with multivessel disease. Acute and long-term results were compared with those of the German Angioplasty Bypass Surgery Investigation trial in a prospective multicenter study. The study included 134 patients in whom 277 lesions were treated. Angiographic success and procedural success were achieved in 268 of 277 lesions (97%) and 118 of 134 patients (88%), respectively. Control angiography performed in 90 of 118 eligible patients (76%) exhibited restenosis in 43 of 182 lesions (24%). Multivariate regression analysis found that a diffuse lesion, the lesion and stent length, and the final luminal diameter were predictive for restenosis. Thus, immediate and long-term results of multivessel coronary intervention utilizing stents were improved compared to percutaneous transluminal coronary angioplasty of multivessel lesions. However, there is still need for improvement of long-term results, especially in particular lesion subgroups.

HIF at the crossroads between ischemia and carcinogenesis

Tissue hypoxia occurs where there is an imbalance between oxygen supply and consumption in both, solid tumors as a result of exponential cellular proliferation and in atherosclerotic diseases as a result of inefficient blood supply. Hypoxia-inducible factor 1 (HIF-1) is central in normal angiogenesis and cancer angiogenesis. HIF-1 is a transcriptional activator composed of an O(2)- and growth factor-regulated HIF-1alpha subunit and a constitutively expressed HIF-1beta subunit. Upon activation, HIF-1 drives the expression of genes controlling cell survival and governing the formation of new blood vessels. A better understanding of the regulation of HIF-1alpha levels by the receptor tyrosine kinases/phosphatidylinositol 3-kinase signaling pathway and by the HIF prolyl hydoxylases has provided new insights into the development of anticancer and revascularization therapeutics. We will focus on the potential of a new pharmacology for regulating HIF pathways in both, cancer and ischemic cardiac diseases. The consequences of the switch of HIF activation in these two disease states and the signaling pathway overlap that atherosclerosis and cancer angiogenesis share are discussed.

Optimal final lumen area and predictors of target lesion revascularization after stent implantation in small coronary arteries

Despite similar early clinical events, patients who undergo treatment of small vessels are at an increased risk for target lesion revascularization (TLR) after coronary artery stenting. We sought to determine predictors of TLR after stent implantation in small coronary arteries. We identified 423 consecutive patients who underwent intravascular ultrasound (IVUS)-guided small vessel stenting procedures in 465 coronary lesions with an angiographic reference vessel diameter of <2.75 mm. Patients were divided into 2 groups based on a final IVUS lumen area of < or =6.0 mm2 (n=345 lesions, group I) and >6.0 mm2 (n=115, group II). Baseline patient characteristics and in-hospital outcomes were similar between the 2 groups, except for a higher rate of restenotic lesions in group I and bifurcation lesions in group II. Group I had higher TLR rates at 1 year compared with group II patients (39% vs 26%, p = 0.02). The TLR rate appeared to decrease with greater stent expansion, especially at >90% of the reference vessel area, as assessed by IVUS. By multivariate analysis, an IVUS final stent area of < or =6 mm2, diabetes, absence of prior myocardial infarction, and history of intervention were independent predictors of 1-year TLR in this population. Final stent area of >6.0 mm2 and greater stent expansion were associated with a decrease in TLR. Therefore, there does not appear to be any "downside" to aggressive stent implantation strategies in small vessels. In contrast, IVUS allows maximization of final lumen dimensions to minimize clinical restenosis.

Effectiveness of stents in small coronary arteries

This study was prospectively randomized to assess the efficacy and safety of Jo heparin-coated stent deployment in small vessels compared with balloon angioplasty. In 202 patients, restenosis in balloon and stent arms was 49% and 30%, respectively.

Early and late outcome of stenting in a consecutive series of patients with coronary lesions in vessels less than 2.8 mm in diameter

In an attempt to determine the early and late outcomes of small vessel stenting, we retrospectively evaluated our database on 51 consecutive patients (41 males, mean age, 57.1 +/- 10.1 years) who underwent stenting of at least one significant lesion in a coronary artery with a reference vessel diameter (RVD) <2.8 mm between March 1999 and March 2001. Sixty balloon expandable tubular stents were implanted in 57 lesions (29 Type B2/C, mean RVD: 2.54 +/- 0.16 mm) without intravascular ultrasound guidance under a heparin-aspirin-ticlopidine regimen. The mean diameter stenosis (DS) decreased from 75.8 +/- 13.6% to 4.2 +/- 1.9% (P<0.0001) with stenting at a mean deployment pressure of 13.6 +/- 1.7 atm and a final balloon to RVD ratio (FB/RVD) of 1.08 +/- 0.03. All stents were deployed successfully. Acute stent thrombosis occurred in 3 patients (6%), one died, and 2 developed non-Q-wave myocardial infarction (procedural success 94%). Clinical follow-up, available in 48 patients, revealed a 29% target lesion revascularization rate, a 2% myocardial infarction rate, and a 71% event-free survival at a mean of 11.6 months. Angiographic follow-up, available in 40 patients, showed a DS of 48.8 +/- 31.3% and a binary restenosis rate of 50% at a mean of 7.7 months. The FB/RVD ratio was significantly lower in the group with restenosis than in the group without (1.06 +/- 0.02 vs 1.1 +/- 0.05, P = 0.04). Subgroup analysis yielded a significantly greater rate of restenosis in diabetics with complex (Type B2/C) lesion morphology compared to nondiabetics with simple (Type A/B1) lesions (75% vs 21%, P < 0.05). In conclusion, stenting in vessels <2.8 mm was found to be associated with a high rate of acute stent thrombosis and in-stent restenosis. Further analysis detected a subgroup of patients without diabetes or complex lesions who could be stented with an acceptable in-stent restenosis rate.

Early experiences of elective stenting for symptomatic stenosis of the M1 segment of the middle cerebral artery: reports of three cases and review of the literature

The role of stenting in the treatment of patients with middle cerebral artery stenosis is not defined because of the high risk and difficulty in tracking. However, recent improvements in the technology, in particular of small, flexible stents and of small, flexible stents with accumulative stenting experience in occlusive intracranial disease endovascular treatment of this disease is now possible. We treated three patients with a symptomatic stenosis of the M1 segment of the middle cerebral artery despite combination anticoagulation therapy. All patients were successfully treated with a balloon-expandable S660 coronary stent. No procedure-related complications occurred and all patients were discharged and remained neurologically stable during the follow-up period (2-12 months). We propose stenting as one of the treatment modalities in patients with symptomatic stenosis of the M1 segment of the middle cerebral artery in selected cases. However, further studies on this new procedure should be done to determine its effect on long-term stroke prevention and to compare its safety with other treatment options.

Morphological predictors of restenosis after coronary stenting in humans

BACKGROUND

Experimental studies suggest that arterial injury and inflammation lead to increased neointimal growth after stenting. Despite the increased use of coronary stents in humans, there are only limited pathological data on the morphological features of in-stent restenosis.

METHODS AND RESULTS

Detailed histology was performed on 116 stents, implanted > or =90 days in 87 coronary arteries, from 56 patients (mean age, 59+/-13 years). The mean duration of stent implant was 10 months. In-stent restenosis was defined as a stent area stenosis of >75%. Lumen area increased as stent area increased (r2=0.27, P=0.0001), but there was a much stronger correlation between stent area and neointimal area (r2=0.70, P<0.0001). Arterial medial fracture was associated with a 29% increase (P<0.01) in neointimal thickness compared with arteries with an intact media. Neointimal thickness (P=0.0001), inflammatory cell density (P<0.0001), and neointimal vascular channel density (P<0.0001) were greater when struts were in contact with a ruptured arterial media compared with fibrous plaque or an intact fibrous cap. Stent strut penetration into a lipid core was associated with increased neointimal thickness (P=0.04) and inflammatory cell density (P=0.03). Neointimal inflammatory cell content was 2.4-fold greater in stents with restenosis versus no restenosis, and inflammation was associated with increased neoangiogenesis.

CONCLUSIONS

Coronary stenting that is accompanied by medial damage or penetration of the stent into a lipid core induces increased arterial inflammation, which is associated with increased neointimal growth. These data suggest the use of stenting strategies that reduce inflammation and neoangiogenesis to reduce the incidence of restenosis.