Clinical impact of in-stent late loss after drug-eluting coronary stent implantation†

Coronary Stenting in High Bleeding Risk Patients With Small Coronary Arteries Followed by One-Month Dual Antiplatelet Therapy: Onyx ONE Clear

Background

Small reference vessel diameters (RVDs) are a predictor of ischemic events after coronary stenting. Among patients at high bleeding risk (HBR) precluding long-term dual antiplatelet therapy (DAPT), those with small vessel disease (SVD) constitute an especially high-risk subgroup. Here, we evaluated the results of a durable-polymer, coronary zotarolimus-eluting stent (ZES) for the treatment of patients with SVD at HBR with 1-month DAPT.

Methods

In the prospective, multicenter Onyx ONE (One-Month DAPT) Clear study, 1506 patients at HBR treated with a ZES that discontinued DAPT at 30 days were included. The clinical outcomes of patients undergoing treatment of lesions with an RVD of ≤2.5 mm (SVD group, as determined by the angiographic core laboratory) were compared with patients without SVD. The primary end point was the composite of cardiac death or myocardial infarction between 1 and 12 months.

Results

Small vessel diameter treatment was performed in 489 (32.5%) patients. Patients with SVD were more likely to be women, have undergone a previous percutaneous intervention, and have multivessel coronary artery disease than patients without SVD. There were no significant differences in lesion, device, or procedural success between the groups. The Kaplan-Meier rate estimate of the primary end point was 8.5% and 6.8% in patients with SVD and those without SVD, respectively (P = .425). No significant differences were found in any secondary end point. The Kaplan-Meier rate of stent thrombosis was 0.6% and 0.8% in patients with SVD and those without SVD, respectively (P = .50).

Conclusions

Among patients at HBR treated with a ZES and 1-month DAPT, those with SVD had favorable 12-month ischemic and bleeding outcomes, which were comparable with those of patients with larger caliber vessels.

Drug-eluting stents for the treatment of coronary artery disease: A review of recent advances

INTRODUCTION

Percutaneous coronary intervention is a widely used procedure for the treatment of coronary artery disease to relieve narrowing or occlusion and improve blood supply. Although only balloon angioplasty was performed in the early period, coronary stents were developed later and coronary drug-eluting stents were introduced to decrease in-stent restenosis, which is related to the proliferation and migration of vascular smooth muscle cells.

AREAS COVERED

The drug-eluting stents are composed of a metallic or polymeric platform, specific drug, and polymers or coating for drug release. In this article, the recent advances in drug-eluting stent technologies for the treatment of coronary artery disease and adjunctive antiplatelet therapy after drug-eluting stent implantation will be reviewed.

EXPERT OPINION

The need for further advances in drug-eluting stents or fully bioresorbable coronary scaffolds still exists to improve patient survival or clinical outcomes. The use for different actions or of combinations of drugs with several actions can be potential. Technological refinement and progress in manufacturing to improve mechanical integrity are needed, particularly for fully bioresorbable scaffolds. For antiplatelet therapy after stenting, clinical bleeding reduction strategies, such as a shortened duration of dual-antiplatelet therapy, are in progress.

Thin- versus thick-strut polymer-free biolimus-eluting stents: the BioFreedom QCA randomised trial

BACKGROUND

The BioFreedom drug-coated stent with a stainless steel platform (BF-SS) has been demonstrated to be efficacious in patients at high bleeding risk and receiv-ing only one-month dual antiplatelet therapy.

AIMS

The aim of this study was to evaluate the efficacy of the new BioFreedom Ultra drug-coated stent with a thin-strut cobalt-chromium platform (BF-CoCr) compared to the BF-SS in an all-comers population undergoing percutaneous coronary intervention (PCI).

METHODS

This was a prospective, multicentre, non-inferiority trial. The primary endpoint was in-stent late lumen loss (LLL) as determined by quantitative coronary angiography at nine-month follow-up. Clinical evaluation was performed at one year.

RESULTS

A total of 200 patients were randomised (1:1) to either the BF-CoCr or the BF-SS stent at eight centres in Spain and Denmark. Baseline clinical and lesion characteristics were similar between the groups. Mean age was 66 years and 23% were female. The mean number of stents implanted per patient was 1.5. At nine-month follow-up, mean in-stent LLL was 0.34±0.49 mm in the BF-CoCr group versus 0.29±0.37 mm in the BF-SS group, p=0.005 for non-inferiority. At one year, target lesion failure was similar between the groups (7.3% in BF-CoCr vs 9.3% in the BF-SS group; p=0.60).

CONCLUSIONS

The BF-CoCr was non-inferior to the BF-SS in terms of in-stent LLL at nine months. Larger studies powered for clinical endpoints are warranted to compare the efficacy of this new platform with currently available DES.

Scaffold underexpansion and late lumen loss after bioresorbable scaffold implantation: Insights from ABSORB JAPAN trial

Background

Device underexpansion is associated with late adverse outcomes after bioresorbable vascular scaffold (BVS) implantation. This study, representing official IVUS results of the ABSORB Japan trial, aimed to characterize IVUS findings, focusing specifically on acute device expansion, and to investigate its impact on late lumen loss (LLL) with Absorb-BVS compared with cobalt-chromium everolimus-eluting stents (CoCr-EES).

Methods

ABSORB Japan enrolled 148 patients (2:1 randomization) in the IVUS cohort. Serial IVUS was prescheduled at post-procedure and 3 years. Acute device expansion was evaluated with respect to the degree and uniformity of the implanted device.

Results

Overall, Absorb-BVS showed smaller and more nonuniform device expansion at post-procedure, compared with CoCr-EES, which was particularly prominent in small-vessel lesions. In serial analysis, Absorb-BVS showed unique associations of smaller device expansion (r = 0.40, p = 0.001) and more nonuniformity (r = 0.29, p = 0.007) at post-procedure with greater LLL at 3 years, primarily attributable to greater negative remodeling (r = 0.39, p = 0.006). In contrast, acute device expansion showed no relation with subsequent lumen change in CoCr-EES. In Absorb-BVS, ischemic-driven target lesion or vessel revascularization (ID-TLR or ID-TVR) at 3 years occurred more frequently in small- versus large-vessel lesions (12.5% vs. 0%, p = 0.04 for ID-TLR and 15.6% vs. 2.3%, p = 0.08 for ID-TVR). Conversely, Absorb BVS had no target lesion nor vessel failure, even in small-vessel lesions, when adequate device expansion was achieved at post-procedure.

Conclusions

Unlike CoCr-EES, underexpansion was associated with greater negative remodeling and LLL in Absorb-BVS. This may in part account for the poorer outcomes of Absorb-BVS than CoCr-EES when under-expanded.

Role of and Recent Evidence for Antiplatelet Therapy in Prevention of Cardiovascular Disease in Diabetes

PURPOSE OF REVIEW

When treating patients with diabetes mellitus (DM), the benefits of antiplatelet therapy in preventing cardiovascular disease must be weighed against an increased risk of bleeding. Recent trials have sought to determine both the optimal anti-platelet regimen for patients with DM, and who specifically requires medication among the DM population. This paper will review recent trials and evidence recommending the use of antiplatelet therapy in the prevention of cardiovascular disease in patients with diabetes.

RECENT FINDINGS

Seven notable trials assessed the effectiveness of antiplatelet therapy in the DM population. The ASCEND trial concluded 100 mg aspirin/day reduced rates of serious vascular events (OR 0.88, p < 0.01) but also increased rates of major bleeding events (OR 1.29, p < 0.01). The DAPT study revealed a longer dual antiplatelet regimen (30 months vs. 18 months) after coronary stent placement was more effective in reducing rates of stent thrombosis (0.5% vs. 1.1%, p = 0.06) and rates of myocardial infarction (3.5% vs. 4.8%, p = 0.06). DECLARE DIABETES showed that adding cilostazol to dual antiplatelet therapy after a coronary stent procedure reduced rates of in-stent and in-segment late loss and increased rates of revascularization (p < 0.04). In PEGASUS-TIMI, daily ticagrelor demonstrated reduced rates of major adverse cardiovascular and cerebrovascular events (OR 0.84, p < 0.04). The DAVID trial compared daily picotamide with daily aspirin therapy, finding reduced mortality rates in the picotamide group (OR 0.55, p < 0.05). Lastly, ACUITY found bivalirudin monotherapy resulted in lower rates of major bleeding events when compared to a glycoprotein IIb/IIa inhibitor and heparin or bivalirudin combination regimen (p < 0.01). Dual antiplatelet therapy guidelines still typically revolve around aspirin, but an increasing number of studies have demonstrated other drugs that may have a role in preventing atherosclerotic cardiovascular disease while decreasing the risk of major bleeding. Overall, it is wise to weigh the cardiovascular risk of a DM patient before prescribing antiplatelet medication. More research is necessary to determine a universal drug or combination of drugs that is safe and effective for DM patients.

The East-West late lumen loss study: Comparison of angiographic late lumen loss between Eastern and Western drug-eluting stent study cohorts

BACKGROUND

Regulatory decisions approving new coronary drug-eluting stent (DES) require mechanistic observations of angiographic late lumen loss (LLL). Patient safety and device approval times could be enhanced if angiographic follow-up data were found to be generalizable across jurisdictions and geographies. The objectives were to assess the comparability of in-segment LLL in Eastern and Western DES populations using the world's largest compilation of follow-up quantitative coronary angiography data.

METHODS

Data from 4 manufacturers involving 29 DES clinical trials in Eastern and Western hemispheres were compiled. "East" and "West" cohorts were defined by trial location. Independent core laboratories quantified in-segment LLL for all studies. East and West were compared before and after adjustment for clinical and anatomic covariates known to correlate with LLL via conditioning on propensity score quintiles. An international panel of experts and regulators prospectively established a clinically meaningful difference between East and West mean in-segment LLL of ±0.40 mm.

RESULTS

The data set comprised 2,047 East and 4,456 West patients. Unadjusted mean ± SD for West and East in-segment LLL (mm) was 0.25 ± 0.46 and 0.12 ± 0.42, respectively (difference 0.13 mm; 95% CI 0.11-0.16). Propensity score-adjusted in-segment LLL East and West least squares means were 0.11 and 0.26 mm, respectively (difference 0.15 mm; 95% CI 0.13-0.18).

CONCLUSIONS

In the world's largest compilation of DES protocol 8- to 13-month angiographic follow-up data, clinically meaningful comparability of in-segment LLL by independent core laboratory quantitative coronary angiography in East and West cohorts was demonstrated in both unadjusted and adjusted comparisons. These findings suggest that DES LLL, once characterized, could be generalized across regulatory jurisdictions over the course of global registration efforts.

Sustained safety and performance of the second-generation drug-eluting absorbable metal scaffold in patients with de novo coronary lesions: 12-month clinical results and angiographic findings of the BIOSOLVE-II first-in-man trial

Aims

Metal absorbable scaffolds constitute a conceptually attractive alternative to polymeric scaffolds. Promising 6-month outcomes of a second-generation drug-eluting absorbable metal scaffold (DREAMS 2G), consisting of an absorbable magnesium scaffold backbone, have been reported. We assessed the 12-month safety and performance of this novel device.

Methods and results

The prospective, international, multi-centre, first-in-man BIOSOLVE-II trial enrolled 123 patients with up to two de novo lesions with a reference diameter between 2.2 and 3.7 mm. All patients were scheduled for angiographic follow-up at 6 months, and—if subjects consented—at 12 months. Dual antiplatelet therapy was recommended for 6 months. Quantitative coronary angiography (QCA) parameters remained stable from 6 to 12 months [paired data of 42 patients: in-segment late lumen loss 0.20 ± 0.21 mm vs. 0.25 ± 0.22 mm, P = 0.117, Δ 0.05 ± 0.21 mm (95% CI: −0.01;0.12); in-scaffold late lumen loss 0.37 ± 0.25 mm vs. 0.39 ± 0.27 mm, P = 0.446, Δ 0.03 ± 0.22 (95% CI: −0.04;0.10), respectively]. Intravascular ultrasound and optical coherence tomography findings corroborated the QCA results. Target lesion failure occurred in four patients (3.4%), consisting of one death of unknown cause, one target-vessel myocardial infarction, and two clinically driven target lesion revascularization. No additional event occurred beyond the 6-month follow-up. During the entire follow-up of 12 months, none of the patients experienced a definite or probable scaffold thrombosis.

Conclusion

The novel drug-eluting metal absorbable scaffold DREAMS 2G showed a continuous favourable safety profile up to 12 months and stable angiographic parameters between 6 and 12 months.

ClinicalTrials.gov identifier

NCT01960504.

Comparison of everolimus- and biolimus-eluting coronary stents with everolimus-eluting bioresorbable vascular scaffolds

BACKGROUND

The first CE-approved bioresorbable vascular scaffold (BVS) is effective at treating simple lesions and stable coronary artery disease, but it has yet to be assessed versus the best-in-class drug-eluting stents (DES).

OBJECTIVES

This study sought to compare the performance of a BVS with that of everolimus-eluting stents (EES) and biolimus-eluting stents (BES) in all-comer patients.

METHODS

The EVERBIO II (Comparison of Everolimus- and Biolimus-Eluting Stents With Everolimus-Eluting Bioresorbable Vascular Scaffold Stents II) trial was a single-center, assessor-blinded study of 240 patients randomly assigned in a 1:1:1 ratio to EES, BES, or BVS. The only exclusion criterion was a reference vessel diameter >4.0 mm, which precluded treatment with BVS. The primary endpoint was angiographic late lumen loss (LLL) at 9 months. Secondary endpoints included patient-oriented major acute coronary events (MACE) (death, myocardial infarction [MI], and any revascularization), device-oriented MACE (cardiac death, MI, and target lesion revascularization), and stent thrombosis at the 9-month clinical follow-up.

RESULTS

Follow-up angiography was performed in 216 patients (90.7%) at 9 months. In-stent LLL was similar between patients treated with BVS (0.28 ± 0.39 mm) and those treated with EES/BES (0.25 ± 0.36 mm; p = 0.30). Clinical outcomes were similar at 9 months: the patient-oriented MACE rate was 27% in BVS and 26% in the EES/BES group (p = 0.83) and the device-oriented MACE rate was 12% in BVS and 9% in the EES/BES group (p = 0.6).

CONCLUSIONS

New-generation metallic DES (EES/BES) were not superior to BVS in terms of angiographic LLL and clinical outcomes. (Comparison of Everolimus- and Biolimus-Eluting Stents With Everolimus-Eluting Bioresorbable Vascular Scaffold Stents [EVERBIO II]; NCT01711931).

Multicenter randomized trial of 3-month cilostazol use in addition to dual antiplatelet therapy after biolimus-eluting stent implantation for long or multivessel coronary artery disease

BACKGROUND

There are conflicting data on the use of cilostazol as triple antiplatelet therapy (TAPT) for improving clinical outcomes after drug-eluting stent implantation. We aimed to evaluate whether 3-month use of cilostazol in addition to dual antiplatelet therapy (DAPT) improved clinical outcomes in patients with long or multivessel coronary artery disease (CAD) after biolimus-eluting stent (BES) implantation.

METHODS

Patients (n = 630) who had been successfully treated with BES implantation for lesions with ≥28 mm in stent length or ≥2 stents for different coronary arteries were enrolled in this prospective randomized multicenter trial. All patients were randomly assigned to receive either DAPT (aspirin and clopidogrel for 12 months, n = 314) or TAPT (DAPT plus 3-month cilostazol use, n = 316). The primary end point was a device-oriented composite consisting of cardiac death, myocardial infarction (not clearly attributable to a nontarget vessel), and ischemia-driven target lesion revascularization at 1-year follow-up.

RESULTS

A total of 314 patients in DAPT and 308 patients in TAPT were analyzed. Multivessel CAD was present in 65.7% of patients. Stents ≥28 mm in length were implanted in 58.1% of lesions. There were no significant differences in baseline and angiographic characteristics between the 2 groups. The primary end point was similar between the 2 groups (2.3% in DAPT vs 1.9% in TAPT, log-rank P = .799).

CONCLUSIONS

In patients treated with BES implantation for long or multivessel CAD, 3 months of cilostazol use in addition to DAPT did not improve clinical outcome at 1-year follow-up.

Incidence and predictors of restenosis after coronary stenting in 10 004 patients with surveillance angiography

OBJECTIVE

Systematic investigation of restenosis after percutaneous coronary intervention (PCI) with bare metal stents (BMS) or first or second generation drug eluting stents (DES) in large scale, broadly inclusive patient populations undergoing follow-up angiography represents a gap in our scientific knowledge. We investigated the incidence of angiographically proven restenosis and its predictors in patients undergoing PCI with stents.

METHODS

All patients undergoing successful implantation of coronary stents for de novo lesions from 1998 to 2009 and follow-up angiography at 6-8 months at two centres in Munich, Germany were eligible for inclusion. Patients with cardiogenic shock, dialysis dependent renal insufficiency or previous cardiac transplantation were excluded. Data were prospectively collected. The incidence of restenosis, defined as diameter stenosis ≥50% in the in-segment area at follow-up angiography, and its predictors were evaluated.

RESULTS

A total of 12 094 patients met inclusion criteria. Angiographic follow-up was available for 10 004 patients (77.5%) with 15 004 treated lesions. Binary restenosis was detected in 2643 (26.4%) patients. Use of first generation DES versus BMS (OR 0.35, 95% CI 0.31 to 0.39) and second generation DES versus first generation DES (OR 0.67, 95% CI 0.58 to 0.77) were independent predictors of lower rates of restenosis. At multivariate analysis, smaller vessel size (OR 1.59, 95% CI 1.52 to 1.68, for each 0.5 mm decrease), total stented length (OR 1.27, 95% CI 1.21 to 1.33, for each 10 mm increase), complex lesion morphology (OR 1.35, 95% 1.21 to 1.51), presence of diabetes mellitus (OR 1.32, 95% 1.19 to 1.46), and history of bypass surgery (OR 1.38, 95% CI 1.20 to 1.58) were independently associated with restenosis and were similar across the spectrum of stent devices.

CONCLUSIONS

In this large cohort of patients with angiographic surveillance we demonstrated the impact of device  development on antirestenotic efficacy, with sequentially improved efficacy from BMS to first generation DES to second generation DES. Predictors of restenosis were small vessel size, increased stented length, complex lesion morphology, diabetes mellitus, and prior bypass surgery.

Randomized comparison of sirolimus-eluting and everolimus-eluting coronary stents in the treatment of total coronary occlusions: results from the chronic coronary occlusion treated by everolimus-eluting stent randomized trial

BACKGROUND

Patients with coronary total occlusions are at especially high risk for restenosis and new revascularizations. Sirolimus-eluting stents dramatically improved the clinical outcome of this subset of patients in randomized trials, but other drug-eluting stents, mainly the everolimus-eluting stent (currently the most frequently used stent), have not yet been evaluated in patients with coronary total occlusions. The objective was to compare the second-generation everolimus-eluting stent with the first-generation sirolimus-eluting stent in patients with coronary total occlusions.

METHODS AND RESULTS

A total of 207 patients with coronary total occlusions and estimated time since occlusion >2 weeks were randomized to everolimus- or sirolimus-eluting stent. The primary end point was in-stent late loss at 9-month angiographic follow-up (noninferiority trial). Clinical follow-up was performed at 1 and 12 months. In-stent late loss at 9 months was 0.29±0.60 versus 0.13±0.69 mm in patients allocated to sirolimus- and everolimus-eluting stent, respectively. The observed difference in in-stent late loss between both groups was -0.16 mm (95% confidence interval, 0.04 to -0.36 mm; P for noninferiority <0.01). The rate of binary angiographic restenosis was 10.8% and 9.1% in patients allocated to sirolimus- and everolimus-eluting stent, respectively (P=0.709), whereas the rate of vessel reocclusion was 3.2% and 1.1%, respectively (P=0.339). At 12 months, the rate of major adverse events was 15.9% versus 11.1% with sirolimus- and everolimus-eluting stent, respectively (P=0.335), and probable or definitive stent thrombosis occurred in 3.0% and 0.0% of patients, respectively (P=0.075).

CONCLUSIONS

In patients with coronary total occlusions, everolimus-eluting stent is as effective as sirolimus-eluting stent.

CLINICAL TRIAL REGISTRATION

URL: http://www.clinicaltrials.gov. Unique identifier: NCT00793221.

Very long-term outcomes after percutaneous coronary intervention with bare metal stents for unprotected left main coronary artery disease

AIMS

The aim of this study was to evaluate very long-term clinical outcomes and potential predictors after percutaneous coronary intervention (PCI) with bare metal stents (BMS) for unprotected left main coronary artery disease (ULMCAD).

METHODS AND RESULTS

From March 1991 to August 2001, 151 patients who underwent PCI with BMS for ULMCAD were investigated retrospectively. The patient-oriented major adverse cardiac events (MACE) were defined as the occurrence of all-cause death, any MI, and any coronary revascularisation. The median follow-up duration was 10.5 years. The mean age was 69.9±11.5 years, and 106 patients (70.2%) were male. At 10 years, the incidences of cardiac death (CD), target lesion revascularisation (TLR) and patient-oriented MACE were 11.1%, 25.2% and 81.9%, respectively. In multivariate analysis, the pre-reference diameter of the left main trunk (LMT) was significantly associated with TLR (adjusted hazard ratio [HR] [95% confidence interval (CI)], 0.28 [0.14-0.54], p<0.001) and the SYNTAX score remained an independent predictor of patient-oriented MACE (adjusted HR [95% CI], 1.03 [1.007-1.05], p=0.009).

CONCLUSIONS

The pre-reference diameter of LMT was significantly associated with TLR, and the SYNTAX score significantly predicted the risk of patient-oriented MACE at 10 years. BMS implantation for larger size of ULMCAD with a lower SYNTAX score was feasible for up to 10 years.

Effectiveness and safety of paclitaxel-eluting stents in patients with ST-segment elevation acute myocardial infarction

AIMS

The efficacy of paclitaxel-eluting stents (PES) in patients with ST-segment elevation acute myocardial infarction (STEMI) has not been demonstrated yet. The aim of the present study was to evaluate the efficacy and safety of PES in patients with STEMI.

METHODS AND RESULTS

A meta-analysis from three randomised trials that compared PES and bare-metal stents in patients with STEMI was performed. Overall, 925 patients were included: 459 allocated to PES, and 466 to bare-metal stents (BMS). The rates of major adverse events (i.e. death, reinfarction, and target vessel revascularisation at 6-12 month follow-up) was compared for patients with PES and BMS. Compared to patients with BMS, a significant reduction in the incidence of events (9.1% vs. 13.9%, p=0.02; OR 0.62; 95%, CI: 0.41-0.93), and target vessel revascularisation (4.7% vs. 8.3%, p=0.03; OR 0.54; 95%, CI 0.31-0.94) was found in patients with PES. The rates of death and reinfarction were similar in BMS and DES patients.

CONCLUSIONS

The use of PES in patients with STEMI is associated with a significant reduction in MACE and need for new revascularisations.

Efficacy and safety of zotarolimus-eluting stents compared with sirolimus-eluting stents in patients undergoing percutaneous coronary interventions--a meta-analysis of randomized controlled trials

BACKGROUND

Whether ZES can further improve angiographic and clinical outcomes compared to SES still remains uncertain.

OBJECTIVES

The aim of this study was to assess the efficacy and safety of zotarolimus-eluting stents (ZES) compared with sirolimus-eluting stents (SES) in patients undergoing percutaneous coronary interventions (PCI).

METHODS

Major electronic information sources were explored for randomized controlled trials comparing ZES with SES among patients undergoing PCI during at least 9 months follow-up. The primary efficacy outcomes were target lesion revascularization (TLR), target vessel revascularization (TVR), and major adverse cardiac events (MACE); safety outcomes were stent thrombosis (ST), myocardial infarction (MI), and cardiac death.

RESULTS

Seven comparative studies were identified (a total of 5983 patients). When compared with ZES at 12-month follow-up, SES significantly reduced risk of MACE (relative risk [RR]: 0.74, 95% confidence interval [CI]: 0.61 to 0.89, p=0.002), and TLR (RR:0.39; 95% CI: 0.29 to 0.52; p<0.00001), without significant differences in terms of TVR (RR:0.68, 95% CI: 0.38 to 1.20; p=0.18), ST (RR:0.71; 95% CI: 0.39 to 1.31; p=0.28), cardiac death (RR:0.83; 95% CI: 0.49-1.42, p=0.50) or MI (RR:1.08; 95%CI: 0.80 to 1.45; p=0.62).

CONCLUSIONS

At 12-month follow-up, SES are superior to ZES in reducing the incidences of TLR and MACE in patients undergoing PCI, without significant differences in terms of TVR, ST, cardiac death, and MI.

Long-term luminal change after drug-eluting stent implantation: serial angiographic follow-up study of the ZEST randomized trial

OBJECTIVE

To evaluate long-term patterns of luminal changes after implantation of different types of drug-eluting stents (DES), we analyzed the serial angiographic outcomes of patients implanted with zotarolimus-eluting stents (ZES), sirolimus-eluting stents (SES), or paclitaxel-eluting stents (PES).

BACKGROUND

Little is known regarding long-term luminal changes after DES implantation.

METHODS

As a subgroup analysis of the ZEST trial, we performed complete angiographic evaluation immediately after the procedure and at 9 months and 2 years in 111 patients with 165 lesions (36 patients with ZES, 40 with SES, and 35 with PES).

RESULTS

Baseline clinical, angiographic, and procedural characteristics were similar among the three groups. Quantitative angiographic analysis revealed significant decreases in minimal luminal diameter 9 months after stent implantation in the ZES (from 2.71 ± 0.49 to 2.21 ± 0.42 mm, P < 0.001), SES (from 2.79 ± 0.49 to 2.58 ± 0.57 mm, P < 0.001), and PES (from 2.66 ± 0.45 to 2.19 ± 0.52 mm, P < 0.001) groups. However, significant late improvements with different degree in luminal diameter were observed between 9 months and 2 years in the ZES (from 2.21 ± 0.42 to 2.39 ± 0.58 mm, P = 0.001), SES (from 2.58 ± 0.57 to 2.66 ± 0.60 mm, P = 0.039), and PES (from 2.19 ± 0.52 to 2.43 ± 0.52 mm, P < 0.001) groups.

CONCLUSION

Serial angiographic follow-up study revealed a biphasic luminal response after DES implantation, characterized by an early progression phase for the first 9 months and a late regression phase from 9 months to 2 years.

Differences in drug-eluting stents used in coronary artery disease

The introduction of drug-eluting stents (DES) has improved the efficacy of percutaneous coronary intervention by addressing the issue of neointimal proliferation, a pathology contributing to restenosis. First-generation stents eluting sirolimus or paclitaxel were joined by second-generation stents, such as the everolimus- and the zotarolimus-eluting stents, promising increased safety and efficacy. As a result, there is a plethora of drug-eluting stents available, with differences in the stent platform, the polymer coating and the eluted drug, which translate into differences in biological markers of efficacy, such as late loss. However, it remains controversial whether these discrepancies have an impact on clinical markers of safety and efficacy, or if the improved efficacy of DES is a class effect. This article reviews the differences between DES by looking into the biological differences and into trials and registries of DES.

Drug-eluting stent restenosis: effect of drug type, release kinetics, hemodynamics and coating strategy

Restenosis following stent implantation diminishes the procedure's efficacy influencing long-term clinical outcomes. Stent-based drug delivery emerged a decade ago as an effective means of reducing neointimal hyperplasia by providing localized pharmacotherapy during the acute phase of the stent-induced injury and the ensuing pathobiological mechanisms. However, drug-eluting stent (DES) restenosis may still occur especially when stents are used in complex anatomical and clinical scenarios. A DES consists of an intravascular metallic frame and carriers which allow controlled release of active pharmaceutical agents; all these components are critical in determining drug distribution locally and thus anti-restenotic efficacy. Furthermore, dynamic flow phenomena characterizing the vascular environment, and shear stress distribution, are greatly influenced by stent implantation and play a significant role in drug deposition and bioavailability within local vascular tissue. In this review, we discuss the performance of DES and the interaction of the different DES components with the hemodynamic milieu emphasizing on the inhibition of clinical restenosis.

Angiographic evidence of progressive lumen narrowing over 2 years following drug-eluting stent implantation

BACKGROUND

Questions persist regarding the ability of drug-eluting stents (DES) to inhibit intimal growth in the long-term.

METHODS

We prospectively enrolled 766 lesions treated with DES that underwent angiographic examination at 6 months and 2 years after stenting. Lesions with 6-month restenosis (>50% of visual stenosis) were excluded. The primary end point was quantitative change in minimal lumen diameter (MLD) according to serial angiography of the segment (in-segment), the stented region (in-stent) and both edges. Late loss, defined as MLD change, was categorized as early (between post-procedure and 6 months), delayed (between 6 months and 2 years), or overall (between post-procedure and 2-years).

RESULTS

MLD progressively decreased in both the in-stent and edge regions at both 6 months and 2 years (p<0.001 in all paired analyses). In-segment MLD decreased from a median 2.27 mm (interquartile range; 1.98, 2.62) at post-procedure to 2.18 mm (1.86, 2.47; p < 0.001 with post-procedure) at 6 months, and to 2.02 mm (1.66, 2.37; p<0.001 with 6 months) at 2 years. Late loss was 0.0 6 mm (-0.05, 0.26) in the early phase, 0.09 mm (-0.01, 0.28) in the delayed phase, and 0.20mm (0.03, 0.50) overall. Two-year angiographic restenosis occurred in 54 (7.0%) lesions, and 65 (8.5%) underwent target lesion revascularization over a median follow-up of 52.5 months.

CONCLUSION

Serial angiographic analysis showed that DES lumen diameter progressively narrowed over 2 years post-procedure. However, the incidence of target lesion revascularization was relatively low due to the small amount of late loss in the delayed phase.

Percutaneous treatment in acute coronary syndromes

Both ST-segment elevation myocardial infarction and non-ST-segment elevation acute coronary syndromes (ACS) are the result of an acute thrombotic lesion obstructing blood flow in the coronary vasculature. Percutaneous treatment has shown to improve clinical outcome in this clinical setting by resolving coronary obstruction with different devices directed to restore coronary blood flow. In comparison with balloon alone angioplasty, implantation of bare metal stents reduced the rate of restenosis and cardiac events, but high rates of restenosis remained, leading to further investigations to develop drug-eluting stents with different pharmacological coatings that reduced restenosis rates and clinical events. In this review, we discuss the current treatment of ACS, reviewing recent randomized clinical trials and advances in medical treatment, including new antiplatelet agents and recent guideline recommendations.

Correlation of angiographic late loss with neointimal coverage of drug-eluting stent struts on follow-up optical coherence tomography

Minimal data have been published on the correlation between angiographic late loss (LL) and incomplete neointimal coverage of struts after drug-eluting stent (DES) implantation. Therefore, we evaluated the relationship between angiographic LL and the percentage of uncovered struts on follow-up optical coherence tomography (OCT) images, in all cross-sections of the lesions. From the OCT registry database, 219 lesions without restenosis after DES implantation were divided into tertiles based on angiographic LL: tertile I (LL ≤ 0.26 mm), tertile II (0.26 < LL < 0.59 mm), and tertile III (≥0.59 mm). Lesions with the percentage of uncovered struts in the highest quartile (≥75th percentile; >6.0%) were defined as highly uncovered; in an independent analysis, lesions without any uncovered strut(s) were defined as completely covered. Higher percentages of uncovered struts were observed in tertile I than in both tertile II and III (10.3 ± 12.8% vs. 4.2 ± 7.4% vs. 2.4 ± 5.1%, respectively; P < 0.001 for I vs. II and I vs. III). Angiographic LL correlated significantly with the percentage of uncovered struts on OCT (r = -0.340, P < 0.001). The best cut-off values of angiographic LL to predict highly uncovered and completely covered lesions were 0.29 mm (area under curves [AUC] = 0.723, P < 0.001) and 0.61 mm (AUC = 0.692, P < 0.001), respectively. Angiographic LL inversely and significantly correlated with the percentage of uncovered struts on OCT after DES implantation.

Periprocedural (30-day) risk of myocardial infarction after drug-eluting coronary stent implantation: a meta-analysis comparing cobalt-chromium and stainless steel drug-eluting coronary stents

AIMS

Because of the reduction in the rate events related with in-stent restenosis, most events after drug-eluting stent implantation occur shortly after coronary stenting. Cobalt-chromium alloys allow to reduce strut thickness and improve flexibility and deliverability of coronary stent platforms, and thus could be associated with lower short-term events after stenting. The aim of this study was to test the hypothesis that drug-eluting coronary stents with a cobalt-chromium platform reduce the incidence of periprocedural (30-day) myocardial infarction in comparison with stainless steel drug-eluting coronary stents.

METHODS AND RESULTS

A meta-analysis from nine randomised trials comparing cobalt-chromium and stainless steel drug-eluting coronary stents that overall included 11,313 patients was performed. The incidence of myocardial infarction, stent thrombosis, and cardiac death at 30 days was compared between both types of stents. At 30 days, the incidence of acute myocardial infarction was significantly lower in patients allocated to cobalt-chromium drug-eluting stents (2.3% vs. 3.9%, respectively; p=0.006; odds ratio 0.72, 95% confidence interval 0.58-0.91), due to a significant reduction in the rate of non-Q-wave myocardial infarction (odds ratio 0.67, 95% confidence interval 0.51-0.88). The incidence of stent thrombosis was similar between both groups of patients, (0.5% vs. 0.5%, p=0.76; odds ratio 1.09, 95% confidence interval 0.63-1.89).

CONCLUSIONS

Drug-eluting coronary stents that use cobalt-chromium stent platforms have a better safety profile at 30 days in comparison with stainless steel drug-eluting stents, due to a significant reduction in the rate of myocardial infarction.

The clinical evaluation of the Endeavor zotarolimus-eluting coronary stent in Japanese patients with de novo native coronary artery lesions: primary results and 3-year follow-up of the Endeavor Japan study

BACKGROUND

Angiographic and clinical outcomes associated with coronary stents eluting the new molecular entity zotarolimus have been well characterized in a variety of geographies and patient subsets. The Endeavor Japan study is the first prospective clinical trial to evaluate the safety and efficacy of the Endeavor zotarolimus-eluting stent (ZES) in the treatment of Japanese patients with single de novo lesions in native coronary arteries.

METHODS AND MATERIALS

This nonrandomized, prospective, multicenter, single-arm trial of 99 subjects with inclusion criteria (elective percutaneous revascularization of single native de novo coronary artery lesions with length ≥14 and ≤27 mm with reference vessel diameters between 2.25 and 3.5 mm) selected to enhance statistical comparability to the ENDEAVOR II randomized study as historical control. The primary end point was target vessel failure (TVF) at 9 months.

RESULTS

At 9 months, the TVF rate was 5.2%, compared with 7.9% in the ZES arm of ENDEAVOR II (P=.412). Notable baseline differences between the Endeavor Japan and ENDEAVOR II populations were mean age (68.2 vs. 61.6 years; P<.001), diabetes (38.4% vs. 18.2%; P<.001), and unstable angina (4.6% vs. 30.3%; P<.001). Despite cohort differences, acute, 9-month, and 3-year clinical outcomes were similar in the two groups, as were 8-month angiographic indices. Finally, out to 3 years, no stent thrombosis was observed in Japanese subjects.

CONCLUSIONS

These findings demonstrate that, in a Japanese population, the Endeavor ZES has similar safety and efficacy compared with other geographies, with sustained clinical benefit and safety to 3 years.

Determining clinical benefits of drug-eluting coronary stents according to the population risk profile: a meta-regression from 31 randomized trials

BACKGROUND

The use of drug-eluting stents (DES) in unfavourable patients has been associated with higher rates of clinical complications and stent thrombosis, and because of that concerns about the use of DES in high-risk settings have been raised.

OBJECTIVE

This study sought to demonstrate that the clinical benefit of DES increases as the risk profile of the patients increases.

METHODS

A meta-regression analysis from 31 randomized trials that compared DES and bare-metal stents, including overall 12,035 patients, was performed. The relationship between the clinical benefit of using DES (number of patients to treat [NNT] to prevent one episode of target lesion revascularization [TLR]), and the risk profile of the population (rate of TLR in patients allocated to bare-metal stents) in each trial was evaluated.

RESULTS

The clinical benefit of DES increased as the risk profile of each study population increased: NNT for TLR=31.1-1.2 (TLR for bare-metal stents); p<0.001. The use of DES was safe regardless of the risk profile of each study population, since the effect of DES in mortality, myocardial infarction, and stent thrombosis, was not adversely affected by the risk profile of each study population (95% confidence interval for β value 0.09 to 0.11, -0.12 to 0.19, and -0.03 to-0.15 for mortality, myocardial infarction, and stent thrombosis, respectively).

CONCLUSIONS

The clinical benefit of DES increases as the risk profile of the patients increases, without affecting safety.

Avoiding restenosis: is there a role for glucocorticoids in the drug-eluting stent era?

Restenosis is an important limitation of percutaneous coronary interventions (PCI). In-stent restenosis is mainly due to neointimal hyperplasia, a proliferative process modulated by inflammatory mechanisms. Numerous technical and pharmacological means have been tested to reduce restenosis rates, with frequently disappointing clinical results. Drug-eluting stents (DES) have demonstrated a high efficacy in reducing restenosis, but there are some associated problems that limit its generalized utilization. Glucocorticoids (GC), as potent anti-inflammatory agents, may exert beneficial effects on neointimal proliferation. Clinical studies with oral and intracoronary GC therapy have demonstrated reduction in restenosis rates in selected patients. Although further investigations are warranted, GC might have a potential role for restenosis prevention in selected cases.

Biolimus-eluting stent with biodegradable polymer versus sirolimus-eluting stent with durable polymer for coronary revascularisation (LEADERS): a randomised non-inferiority trial

BACKGROUND

A novel stent platform eluting biolimus, a sirolimus analogue, from a biodegradable polymer showed promising results in preliminary studies. We compared the safety and efficacy of a biolimus-eluting stent (with biodegradable polymer) with a sirolimus-eluting stent (with durable polymer).

METHODS

We undertook a multicentre, assessor-blind, non-inferiority study in ten European centres. 1707 patients aged 18 years or older with chronic stable coronary artery disease or acute coronary syndromes were centrally randomised by a computer-generated allocation sequence to treatment with either biolimus-eluting (n=857) or sirolimus-eluting (n=850) stents. The primary endpoint was a composite of cardiac death, myocardial infarction, or clinically-indicated target vessel revascularisation within 9 months. Analysis was by intention to treat. 427 patients were randomly allocated to angiographic follow-up, with in-stent percentage diameter stenosis as principal outcome measure at 9 months. The trial is registered with ClinicalTrials.gov, number NCT00389220.

FINDINGS

We analysed all randomised patients. Biolimus-eluting stents were non-inferior to sirolimus-eluting stents for the primary endpoint at 9 months (79 [9%] patients vs 89 [11%], rate ratio 0.88 [95% CI 0.64-1.19], p for non-inferiority=0.003, p for superiority=0.39). Frequency of cardiac death (14 [1.6%] vs 21 [2.5%], p for superiority=0.22), myocardial infarction (49 [5.7%] vs 39 [4.6%], p=0.30), and clinically-indicated target vessel revascularisation (38 [4.4%] vs 47 [5.5%], p=0.29) were similar for both stent types. 168 (79%) patients in the biolimus-eluting group and 167 (78%) in the sirolimus-eluting group had data for angiographic follow-up available. Biolimus-eluting stents were non-inferior to sirolimus-eluting stents in in-stent percentage diameter stenosis (20.9%vs 23.3%, difference -2.2% [95% CI -6.0 to 1.6], p for non-inferiority=0.001, p for superiority=0.26).

INTERPRETATION

Our results suggest that a stent eluting biolimus from a biodegradable polymer represents a safe and effective alternative to a stent eluting sirolimus from a durable polymer in patients with chronic stable coronary artery disease or acute coronary syndromes.

FUNDING

Biosensors Europe SA, Switzerland.

Serpins in thrombosis, hemostasis and fibrinolysis

Hemostasis and fibrinolysis, the biological processes that maintain proper blood flow, are the consequence of a complex series of cascading enzymatic reactions. Serine proteases involved in these processes are regulated by feedback loops, local cofactor molecules, and serine protease inhibitors (serpins). The delicate balance between proteolytic and inhibitory reactions in hemostasis and fibrinolysis, described by the coagulation, protein C and fibrinolytic pathways, can be disrupted, resulting in the pathological conditions of thrombosis or abnormal bleeding. Medicine capitalizes on the importance of serpins, using therapeutics to manipulate the serpin-protease reactions for the treatment and prevention of thrombosis and hemorrhage. Therefore, investigation of serpins, their cofactors, and their structure-function relationships is imperative for the development of state-of-the-art pharmaceuticals for the selective fine-tuning of hemostasis and fibrinolysis. This review describes key serpins important in the regulation of these pathways: antithrombin, heparin cofactor II, protein Z-dependent protease inhibitor, alpha(1)-protease inhibitor, protein C inhibitor, alpha(2)-antiplasmin and plasminogen activator inhibitor-1. We focus on the biological function, the important structural elements, their known non-hemostatic roles, the pathologies related to deficiencies or dysfunction, and the therapeutic roles of specific serpins.