Two-year clinical outcome after coronary stenting of small vessels using 2.25-mm sirolimus- and paclitaxel-eluting stents: Insight into the RESEARCH and T-SEARCH registries

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 in patients with very small coronary artery disease treated with drug-eluting stents: An observational study in the Indian population

Percutaneous coronary intervention (PCI) in very small vessel coronary arteries is challenging due to adverse short-term as well as long-term outcomes. This single-arm, open-label, observational study assessed 1-year clinical outcomes of drug-eluting stents (DES) in Indian patients undergoing PCI for symptomatic very small-calibre coronary artery disease. It enrolled 66 Indian patients with 74 very small coronary artery lesions (reference vessel diameter: ≥2.0 and ≤ 2.25 mm); eligible for implantation with 2.25 mm DES. The primary endpoint of major adverse cardiovascular events (MACE) was 3.0% indicating favourable 1-year clinical outcomes of DES in very small coronary artery lesions in Indian patients.

A Prospective Multicenter Randomized Trial to Assess the Effectiveness of the MagicTouch Sirolimus-Coated Balloon in Small Vessels: Rationale and Design of the TRANSFORM I Trial

AIMS

The objective of the study is to assess the efficacy and safety of the novel Magic Touch sirolimus coated-balloon (SCB) when compared to the SeQuent Please Neo paclitaxel coated balloon (PCB) for the treatment of de-novo small vessel coronary artery diseases (SVD).

STUDY DESIGN

The TRANSFORM I study is a randomized, multicenter, non-inferiority trial with the intent to enroll a total of 114 patients with a de-novo SVD (≤2.5 mm). Vessel size will be pre-screened by on-line QCA. After successful pre-dilatation without major coronary dissections (type C-F) nor Thrombolysis In Myocardial Infarction trial [TIMI] grade flow ≤2, patients will be enrolled in a 1:1 randomization to receive treatment with either the novel SCB balloon or the comparative PCB balloon. The balloon sizing will be selected according to the lumen-based approach derived from optical coherence tomography (OCT). The primary endpoint is 6-month mean net lumen diameter gain (6-month minimum lumen diameter [MLD] minus baseline MLD) assessed by quantitative coronary analysis (QCA) with non-inferiority margin of 0.3 mm in per-protocol analysis. The clinical follow-up will be conducted up to 1 year. The enrollment started in September 2020 and will complete in April 2021.

CONCLUSIONS

The TRANSFORM I trial will assess the efficacy of novel SCB in terms of non-inferiority to conventional PCB with a novel OCT measurement approach in patients with a de-novo SVD. Clinical Trial Registration URL: https://clinicaltrials.gov. Unique identifier: NCT03913832.

The OPTIMIZE randomized trial to assess safety and efficacy of the Svelte IDS and RX Sirolimus-eluting coronary stent Systems for the Treatment of atherosclerotic lesions: Trial design and rationale

Coronary stenting without angioplasty pretreatment (direct stenting) may simplify procedures in appropriate lesions. Direct stenting is facilitated by smaller profile coronary stent platforms. The present study was designed for regulatory approval of a novel drug-eluting coronary stent and incorporates both randomized comparison for non-inferiority to an approved predicate device as well as a nested evaluation of subjects eligible for direct stenting. STUDY DESIGN AND OBJECTIVES: Prospective, single-blind, randomized, active-control, multi-center study designed to assess the safety and efficacy of the novel Svelte sirolimus-eluting stent (SES) systems. A total of 1630 subjects with up to 3 target lesions will be randomized 1:1 to the Svelte SES versus either the Xience or Promus everolimus-eluting stents (control). Randomization will be stratified by whether or not a direct stenting strategy is planned by the investigator. The primary endpoint is target lesion failure (TLF) at 12 months post index procedure, defined as cardiac death, target vessel myocardial infarction, or clinically driven target lesion revascularization, and the primary analysis is a non-inferiority test with a non-inferiority margin of 3.58%. Secondary clinical endpoints include individual components of TLF, stent thrombosis and measures of procedural resource utilization including contrast administration, fluoroscopy exposure and procedural resource utilization as well as costs. CONCLUSION: The OPTMIZE Trial will evaluate the safety, efficacy and clinical value of the novel Svelte SES in subjects with up to 3 lesions, and will provide a comparison of direct stenting between randomized devices.

First-generation paclitaxel- vs. second-generation zotarolimus-eluting stents in small coronary arteries: the BASKET-SMALL Pilot Study

Introduction

Event rates after percutaneous coronary interventions (PCI) are higher in small than large coronary vessels but may vary between different drug-eluting stent (DES) types.

Aim

To assess the efficacy of two different DES in small vessel disease.

Material and methods

Patients with small vessel PCI were randomised 1 : 1 to a first-generation paclitaxel- vs. a second-generation zotarolimus-eluting stent. The primary endpoint was a composite of cardiac death, non-fatal myocardial infarction, and target vessel revascularisation after 2 years.

Results

Overall, 191 patients were enrolled: 100 with a paclitaxel- and 91 with a zotarolimus-eluting stent. Baseline characteristics were similar in both groups. After 2 years, rates of the primary endpoint were numerically higher for zotarolimus- than paclitaxel-eluting stents (9.9% vs. 5.0%, hazard ratio 2.09, 95% confidence interval (CI) 0.7–6.2, p = 0.19), which was mainly driven by higher rates of target vessel revascularisation (6.6% vs. 2.0%, hazard ratio 3.39, 95% CI: 0.68–16.78, p = 0.14). Based on this, a total of 1,019 patients would be necessary to demonstrate at least non-inferiority between the DES used.

Conclusions

In this pilot study, paclitaxel-eluting stents had a favourable efficacy profile in small vessel disease, although the numbers were too small to draw final conclusions. Based on the prohibitively high sample size for a randomized controlled trial between DES, other treatment options should be considered.

Vessel Size and Long-Term Outcomes After Limus-Based Drug-Eluting Stent Implantation Focusing on Medium- and Small-Diameter Vessels

Introduction:

This study aimed to evaluate the efficacy and safety of limus-based drug-eluting stent (DES) implanted in medium or small coronary vessels during a very long-term follow-up period.

Methods:

A total of 2383 patients treated with 2916 limus-based DES between April 2003 and March 2015 were evaluated. The enrolled patients were stratified into 3 groups according to the reference vessel diameter: group A: ≤2.5 mm; group B: 2.51 to 3.00 mm; group C: 3.01 to 3.50 mm.

Results:

Group A had a significantly higher loss index and binary restenosis rate than the other 2 groups at 9 months of angiographic follow-up. Group A also had a significantly higher rate of target lesion revascularization and a lower rate of major adverse cardiovascular event–free survival than the other 2 groups after a follow-up period of 68 ± 59 months. The long-term cardiovascular event–free survival curves based on a Cox regression model showed large vessel size, and second-generation DES had better outcomes.

Conclusion:

An inverse relationship between vessel size (≤3.5 mm) and clinical outcomes was noted in patients who received limus-based DES implantation.

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.

Composite outcomes in 2.25-mm drug eluting stents: a systematic review

BACKGROUND

Coronary atherosclerosis often involves small-caliber coronaries, yet the safety and efficacy of 2.25-mm DES have been poorly defined, with a general lack of separation of 2.25 with 2.5-mm performance. No randomized head-to-head 2.25 mm DES studies have been reported. There are several single-arm prospective studies, and we aim to systematically review all published specific 2.25-mm data to estimate composite DES-specific performance and highlight current knowledge gaps.

METHODS

We performed a systematic literature search of PubMed, EMBASE, Web of Science and Cochrane database for clinical trials of 2.25-mm DES. Angiographic and composite clinical outcomes were compared with descriptive statistics.

RESULTS

2.25 mm-Paclitaxel (PES), sirolimus (SES), everolimus (EES) and platinum chromium EES DES-specific outcomes have been reported. Death at 12 months for SES, PES, EES and platinum chromium EES was 1.3%, 3.0%, 1.5%, and 4.4%. Rates of target vessel revascularization at 12 months for SES, PES, EES and platinum chromium EES were 5.7%, 13.3%, 8.8%, and 3.3%. Angiographic outcomes at 9 months to one year were as follows: mean late lumen loss (LLL) for SES, PES, and EES was 0.15 ± 0.11-mm, 0.28 ± 0.11-mm, and 0.16 ± 0.41-mm and mean diameter restenosis for SES, PES, and EES were 29.5 ± 6.2%, 34.7 ± 4.2%, and 20.9 ± 22.5%. Reported stent thrombosis rates for 2.25-mm DES were low ranging from 0% to 2.2% in up to 24-months of follow-up.

CONCLUSIONS

This systematic review summarizes and tabulates all available specific data on 2.25-mm DES. Based on our descriptive analysis, 2.25-mm DESs have a favorable safety and efficacy profile for the treatment of very small coronary lesions.

The everolimus-eluting Xience stent in small vessel disease: bench, clinical, and pathology view

Coronary artery disease (CAD) is the leading cause of morbidity and mortality worldwide. The pathogenesis of CAD relates to the presence of atherosclerotic plaques in the coronary arteries, which are most frequently treated today by percutaneous coronary intervention. Small vessel disease treatment represents one-third of all percutaneous coronary interventions with higher rates of restenosis and major adverse cardiac events. Initially, drug-eluting stents (DES) were developed to reduce in-stent restenosis, improving clinical outcomes and reducing the need for target vessel revascularization. However, late and very late stent thrombosis emerged as a new problem compromising DES’s long-term results. The cobalt–chromium everolimus-eluting stent (CoCr-EES) represents the results of an evolutionary process in DES technology aimed at improving the shortcomings of first-generation DES. Small vessel CAD has historically been an obstacle to long-term patency following implantation of DES. Antirestenotic efficacy has been shown to be of high relevance in small vessels. Therefore, stent selection may play an important role in determining outcomes in this subgroup of patients. This article will review the performance of CoCr-EES in the treatment of small vessel CAD from preclinical, clinical, and pathology perspectives, and it will highlight the most important findings in this regard.

Comparison of long-term outcomes between everolimus-eluting and sirolimus-eluting stents in small vessels

Although second-generation everolimus-eluting stents (EESs) have demonstrated superiority over first-generation paclitaxel-eluting stents for a broad subset of patients and lesions, it is unclear whether the same applies to sirolimus-eluting stents (SESs). The present study compared the long-term clinical outcomes between EESs and SESs in patients with small coronary artery disease. A cohort of 643 patients treated with EESs (220 patients with 245 lesions) or SESs (423 patients with 523 lesions) in small vessel lesions (defined as those receiving stents ≤2.5 mm) were retrospectively analyzed. The end points included target lesion revascularization, target vessel revascularization, major adverse cardiovascular events (all-cause death, myocardial infarction, or target lesion revascularization), and definite stent thrombosis at 1 year of follow-up. The baseline characteristics were generally similar between the 2 groups, except that more systemic hypertension was seen in the EES group and more patients had a family history of coronary artery disease in the SES group. The 1-year target lesion revascularization (5.6% vs 4.8%, p = 0.68) and target vessel revascularization (5.6% vs 7.6%, p = 0.33) rates showed no significant differences between the EES and SES groups. Overall major adverse cardiovascular events occurred in 9.1% of the EES- and 8.6% of SES-treated patients (p = 0.83). This similar major adverse cardiovascular events rate remained after adjustment. The rate of stent thrombosis was 0% in the EES group and 1.2% in the SES group (p = 0.17). In conclusion, EESs demonstrated comparable clinical outcomes to those of SESs in small vessel interventions. The absence of stent thrombosis among patients treated with EESs suggests a good safety profile for this second-generation drug-eluting stent, which should be carefully studied in a larger series of patients with small vessel disease.

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.

Small coronary vessel angioplasty: outcomes and technical considerations

Small vessel (<3 mm) coronary artery disease is common and has been identified as independent predictor of restenosis after percutaneous coronary intervention. It remains controversial whether bare-metal stent (BMS) implantation in small vessels has an advantage over balloon angioplasty in terms of angiographic and clinical outcomes. Introduction of drug-eluting stent (DES) has resulted in significant reduction in restenosis and the need for repeat revascularization. Several DESs have been introduced resulting in varying reduction in outcomes as compared with BMS. However, their impact on outcomes in small vessels is not clearly known. It is expected that DES could substantially reduce restenosis in smaller vessels. Large, randomized studies are warranted to assess the impact of different DESs on outcomes in patients with small coronary arteries.

Off-label use of drug-eluting versus bare metal stents: a lesion-specific systematic review of long-term outcomes

OBJECTIVE

The purpose of this systematic review was to evaluate differences in lesion-specific outcomes with the "off-label" use of drug-eluting stents (DES) versus bare metal stents (BMS).

METHODS

MEDLINE, PubMed, the Cochrane databases, and other Web were searched for studies evaluating off-label use of DES and BMS with the same characteristics. Of 1,258 abstracts or manuscripts reviewed, 112 studies were included (total N = 23,438). Studies were excluded if patients received both types of stent or no stent; lesion type was unknown; lesion-specific outcomes for ≥6 months were unavailable; or <25 patients were enrolled.

RESULTS

Overall mortality at 6-12 months was approximately 3% for BMS and DES for off-label use. Increase in mortality was greater from 6-12 months to 2 years with BMS than with DES (3.3%-9.1%; 2.8%-4.1%); however, rates were similar at 3 years (BMS: 18.8%; DES:15.3%). Myocardial Infarction rates were similar for both types at 6-12 months (BMS: 6.5%; DES: 6.0%). Overall rates of stent thrombosis were 1.8% and 1.7% for BMS and DES, respectively. Similar or slightly lower rates of stent thrombosis were seen for most lesion types, except higher rates for small vessels for BMS (5.2%) and true bifurcation for DES (3.3%). Rates of target lesion revascularization (TLR) were 7.5% for BMS and 19.6% for DES at 6-12 months. At 2-years TLR remained lower than DES. When the combined group was compared to registry data alone, similar values were seen.

CONCLUSIONS

Rates of mortality, myocardial infarction (MI), and stent thrombosis were similar in patients receiving BMS or DES, while TLR rates were lower in DES patients.

Treatment of small coronary arteries with a paclitaxel-coated balloon catheter

BACKGROUND

Treatment of lesions in small coronary arteries by percutaneous transluminal coronary intervention is limited by a high recurrence rate. We assessed the use of a paclitaxel-coated balloon in this indication.

METHODS

One-hundred eighteen patients with stenoses in small coronary vessels were treated by a paclitaxel-coated balloon (3 microg/mm(2)). The main inclusion criteria encompassed diameter stenosis of > or =70% and < or =22 mm in length with a vessel diameter of 2.25-2.8 mm. Follow-up angiography was performed at scheduled 6-month post-intervention or whenever driven by clinical or electrocardiographic signs of ischemia. The primary endpoint was angiographic in-segment late lumen loss.

RESULTS

Eighty-two of 118 patients (70%) with a vessel diameter of 2.35 +/- 0.19 mm were treated with the drug-coated balloon only, while 32 patients required additional stent deployment. The mean in-segment late lumen loss was 0.28 +/- 0.53 mm. In patients treated with the drug-coated balloon only, the in-segment late lumen loss was 0.16 +/- 0.38 mm. At 12 months, the rate of major adverse cardiac events was 15% which was primarily due to the need for target lesion revascularization in 14 patients (12%). In those with additional bare metal stent implantation geographical mismatch between coated-balloon dilatation and stent implantation was significantly associated with the occurrence of restenosis.

CONCLUSION

Treatment of coronary stenosis in small coronary vessels with the paclitaxel-coated balloon was well tolerated. It may offer an alternative to the implantation of a drug-eluting stent (ClinicalTrials.gov Identifier: NCT00404144).

First-in-man use of polymer-free valsartan-eluting stents in small coronary vessels: a comparison to polymer-free rapamycin (2%)-eluting stents

Introduction. Orally administered angiotensin receptor antagonists administered after bare-metal stent implantation and even after drug-eluting stent implantation seem to lower in-stent restenosis rates.Whether valsartan-eluting stents are similarly effective was tested here in a first-in-man trial.

Materials and methods. The efficacy of a polymer-free drug-eluting stent coated with 300 mcg valsartan was compared to a coating with a 2% rapamycin solution in small (≤ 2.5 mm) coronary vessels with and without oral valsartan on the basis of the YUKON Choice stent system (Translumina GmbH, Hechingen, Germany). Fifteen patients (eight males, mean age 64.4±7.7 years) were treated with YUKON Choice valsartan-eluting stents and 30 patients (24 males, mean age 65.7±8.4 years) received YUKON Choice rapamycin-eluting stents. Clopidogrel was given for six months in all patients.

Results. Within the first 30 days, no adverse events occurred in either group. Binary in-stent restenosis rate was 30.8% (four in 13 angiographic controls) in the valsartan-eluting stent group and 35.0% (eight in 20 angiographic controls) in the rapamycin-eluting YUKON Choice stent group. Mean late lumen loss was 0.78±0.53 mm and 0.79±0.58 mm, respectively. Target lesion and target vessel revascularisation rate was 26.6% and 25.0%, respectively. No restenoses in rapamycin-eluting YUKON Choice stents appeared in 12 patients with adjunct oral valsartan administration.

Conclusions. If polymer-free YUKON Choice stents are used in small vessels, valsartan-eluting stents show an identical efficacy as rapamycin-loaded stents. In patients with rapamycin-eluting YUKON Choice stents it seems that the efficacy can be increased by oral valsartan administration.

Fractional flow reserve versus angiography for guiding percutaneous coronary intervention

BACKGROUND

In patients with multivessel coronary artery disease who are undergoing percutaneous coronary intervention (PCI), coronary angiography is the standard method for guiding the placement of the stent. It is unclear whether routine measurement of fractional flow reserve (FFR; the ratio of maximal blood flow in a stenotic artery to normal maximal flow), in addition to angiography, improves outcomes.

METHODS

In 20 medical centers in the United States and Europe, we randomly assigned 1005 patients with multivessel coronary artery disease to undergo PCI with implantation of drug-eluting stents guided by angiography alone or guided by FFR measurements in addition to angiography. Before randomization, lesions requiring PCI were identified on the basis of their angiographic appearance. Patients assigned to angiography-guided PCI underwent stenting of all indicated lesions, whereas those assigned to FFR-guided PCI underwent stenting of indicated lesions only if the FFR was 0.80 or less. The primary end point was the rate of death, nonfatal myocardial infarction, and repeat revascularization at 1 year.

RESULTS

The mean (+/-SD) number of indicated lesions per patient was 2.7+/-0.9 in the angiography group and 2.8+/-1.0 in the FFR group (P=0.34). The number of stents used per patient was 2.7+/-1.2 and 1.9+/-1.3, respectively (P<0.001). The 1-year event rate was 18.3% (91 patients) in the angiography group and 13.2% (67 patients) in the FFR group (P=0.02). Seventy-eight percent of the patients in the angiography group were free from angina at 1 year, as compared with 81% of patients in the FFR group (P=0.20).

CONCLUSIONS

Routine measurement of FFR in patients with multivessel coronary artery disease who are undergoing PCI with drug-eluting stents significantly reduces the rate of the composite end point of death, nonfatal myocardial infarction, and repeat revascularization at 1 year. (ClinicalTrials.gov number, NCT00267774.)

Acute coronary syndrome due to complete bare metal stent fracture in the right coronary artery

Stent fracture (SF) was suggested to be an unusual cause of restenosis after drug eluting-stent implantation. However, angiographically visible complete SF after bare metal stent (BMS) implantation is extremely rare. Here we report a case of SF of a BMS representing with acute coronary syndrome (ACS). To our knowledge, this is the first report of early fracture of a BMS in the right coronary artery, resulting in ACS.

Clinical and angiographic follow-up of small vessel lesions treated with paclitaxel-eluting stents (from the TRUE Registry)

Several randomized trials have shown that sirolimus-eluting stents and paclitaxel-eluting stents (PES) are effective in reducing restenosis in respect to bare-metal stents, including the subset of small vessels. The objective of this study was to evaluate "real world" angiographic and clinical outcomes of a large series of patients enrolled in the TRUE registry and treated with PES for both small vessel and very small vessel lesions. A consecutive series of 675 patients (926 lesions) with reference vessel diameter <2.75 mm measured by quantitative coronary angiography analysis were analyzed. The primary end point was the rate of angiographic in-stent restenosis and 1-year major adverse cardiac events. In this study 390 lesions were identified as small vessel (reference vessel diameter >or=2.25 and <2.75 mm) and 536 lesions as very small vessel (reference vessel diameter <2.25 mm). Overall in-stent restenosis was 15.5% (n = 96). Compared with small vessel, the very small vessel lesions had more in-stent restenosis (21.7% vs 11.4%, p <0.001) and in-segment restenosis (29.3% vs 22.5%, p = 0.055). The majority of the restenotic lesions (n = 125) were focal (57%, n = 71). At 1 year, cardiac death was 1.6% (n = 11), acute myocardial infarction 0.5% (n = 4.), and the target lesion revascularization 12.8% (n = 86). Cumulative major adverse cardiac events rate was 17.3% (n = 119). The rate of definite and probable stent thrombosis was 0.9% (n = 8). In conclusion, in comparison with historical bare-metal stent controls, this large series of small vessel lesions treated with PES confirms previous results reporting the efficacy of PES in small vessels. The rate of subacute and late stent thrombosis was low in this subgroup of patients.

Clinical use of sirolimus-eluting stents

Drug-eluting stents, or intracoronary stents that combine the local delivery of antirestenotic pharmacologic therapies while maintaining the mechanical advantage of bare metal stents over balloon angioplasty alone, are a highly complex technology that have profoundly affected the practice of percutaneous coronary intervention over the last 5 years. These devices were designed specifically to treat the neointimal hyperplasia occurring after conventional bare metal stent placement, and have been remarkably successful in this regard. However, recent concerns have been raised regarding the long-term safety of these devices, particularly when used outside of the specific patient and lesion subsets studied in the pivotal randomized trials that led to device approval by regulatory bodies within the United States and abroad. This review aims to present a brief description of the sirolimus-eluting stent device platform and its mechanism of action, followed by an overview of current data regarding efficacy and safety regarding the clinical use of sirolimus-eluting stent technology.

Frequency of stent fracture as a cause of coronary restenosis after sirolimus-eluting stent implantation

Stent fracture (SF) was suggested as a cause of restenosis after sirolimus-eluting stent (SES) implantation. This study was performed to evaluate the incidence and characteristics of SF to determine its contribution to restenosis in patients with in-stent restenosis (ISR) after SES implantation. From May 2003 to February 2006, SESs were used for percutaneous coronary intervention in 868 patients with 1,109 coronary narrowings. Follow-up coronary angiography was performed in 366 patients (42%), and 26 ISR lesions were observed. These patients were enrolled in this study. SF was divided into 3 types as avulsion, collapse, and partial based on the findings of fluoroscopy, coronary angiography, and intravascular ultrasound study. Of 26 patients with ISR lesions, SF was identified in 10. SF types were avulsion (5 patients), collapse (2 patients), and partial (3 patients). SF was identified at the midshaft (7 patients) and overlap sites (3 patients) of stents. SF was not observed in the 30 patients with ISR after bare-metal Bx Velocity stent implantation. Four patients with SF were treated with paclitaxel-eluting stents. In conclusion, SF is 1 of the leading causes of ISR after SES implantation. Careful fluoroscopic examination is necessary at the time of follow-up angiography to identify this problem.

Sirolimus and paclitaxel provoke different vascular pathological responses after local delivery in a murine model for restenosis on underlying atherosclerotic arteries

BACKGROUND

Drug-eluting stents (DES) have been introduced successfully in clinical practice to prevent post-angioplasty restenosis. Nevertheless, concerns about the safety of DES still exist.

OBJECTIVE

To investigate the vascular pathology and transcriptional responses to sirolimus and paclitaxel in a murine model for restenosis on underlying diseased atherosclerotic arteries.

METHODS

Atherosclerotic lesions were induced by placement of a perivascular cuff around the femoral artery of hypercholesterolaemic ApoE*3-Leiden transgenic mice. Two weeks later these cuffs were replaced either by sirolimus- or paclitaxel-eluting cuffs. The vascular pathological effects were evaluated after two additional weeks.

RESULTS

Both anti-restenotic compounds significantly inhibited restenotic lesion progression on the atherosclerotic plaques. Vascular histopathological analyses showed that local delivery of sirolimus has no significant adverse effects on vascular disease. Conversely, high dosages of paclitaxel significantly increased apoptosis, internal elastic lamina disruption, and decreased medial and intimal smooth muscle cells and collagen content. Moreover, transcriptional analysis by real-time RT-PCR showed an increased level of pro-apoptotic mRNA transcripts (FAS, BAX, caspase 3) in paclitaxel-treated arteries.

CONCLUSIONS

Sirolimus and paclitaxel are effective in preventing restenosis. Sirolimus has no significant effect on arterial disease. In contrast, paclitaxel at high concentration demonstrated adverse vascular pathology and transcriptional responses, suggesting a narrower therapeutic range of this potent drug. Since the use of overlapping stents is becoming more common in DES technology, this factor is important, given that higher dosages of paclitaxel may lead to increased apoptosis in the vessel wall and, consequently, to a more unstable phenotype of the pre-existing atherosclerotic lesion.