Rationale and design of the Patient Related OuTcomes with Endeavor versus Cypher stenting Trial (PROTECT): randomized controlled trial comparing the incidence of stent thrombosis and clinical events after sirolimus or zotarolimus drug-eluting stent implantation

Long-term safety of bioresorbable scaffolds: insights from a network meta-analysis including 91 trials

AIMS

The aim of this study was to investigate the long-term safety and efficacy of biodegradable scaffolds and metallic stents.

METHODS AND RESULTS

We analysed a total of 91 randomised controlled trials with a mean follow-up of 3.7 years in 105,842 patients which compared two or more coronary metallic stents or biodegradable scaffolds and reported the long-term clinical outcomes (≥2 years). Network meta-analysis showed that patients treated with the Absorb bioresorbable vascular scaffold (BVS) had a significantly higher risk of definite or probable scaffold thrombosis (ScT) compared to those treated with metallic DES. The risk of very late ScT was highest with the Absorb BVS among comparators. Pairwise conventional meta-analysis demonstrated that the elevated risk of ScT with Absorb BVS compared to cobalt-chromium everolimus-eluting stents was consistent across the time points of ≤30 days (early), 31 days - 1 year (late) and >1 year (very late) ScT. In addition, target lesion failure rates were significantly higher in the Absorb BVS cohort, driven by both increased risk of target vessel myocardial infarction and ischaemia-driven target lesion revascularisation.

CONCLUSIONS

Absorb BVS implantation was associated with increased risk of long-term and very late ScT compared to current-generation metallic DES. The risk of ScT occurred with a rising trend beyond one year.

Validating Utility of Dual Antiplatelet Therapy Score in a Large Pooled Cohort From 3 Japanese Percutaneous Coronary Intervention Studies

Background:

The dual antiplatelet therapy (DAPT) score was developed to estimate ischemic and bleeding risks from the DAPT study. However, few studies validated its utility externally. We sought to validate the utility of the DAPT score in the Japanese population.

Methods:

In a pooled cohort of 3 studies conducted in Japan (the CREDO-Kyoto [Coronary Revascularization Demonstrating Outcome Study in Kyoto] Registry Cohort-2, RESET [Randomized Evaluation of Sirolimus-Eluting Versus Everolimus-Eluting Stent Trial], and NEXT [NOBORI Biolimus-Eluting Versus XIENCE/PROMUS Everolimus-Eluting Stent Trial]), we compared risks for ischemic and bleeding events from 13 to 36 months after percutaneous coronary intervention among patients with a DAPT score ≥2 (high DS) and a DAPT score <2 (low DS).

Results:

Among 12 223 patients receiving drug-eluting stents who were free from ischemic or bleeding events at 13 months after percutaneous coronary intervention, 3944 patients had high DS and 8279 had low DS. The cumulative incidence of primary ischemic end point (myocardial infarction/stent thrombosis) was significantly higher in high DS than in low DS (1.5% versus 0.9%, P =0.002), whereas the cumulative incidence of primary bleeding end point (GUSTO moderate/severe) tended to be lower in high DS than in low DS (2.1% versus 2.7%, P =0.07). The cumulative incidences of cardiac death, myocardial infarction, and stent thrombosis were also significantly higher in high DS than in low DS (2.0% versus 1.4%, P =0.03; 1.5% versus 0.8%, P =0.002; 0.7% versus 0.3%, P <0.001, respectively), whereas the cumulative incidences of noncardiac death and GUSTO severe bleeding were significantly lower in high DS than in low DS (2.4% versus 3.9%, P <0.001; 1.0% versus 1.6%, P =0.03, respectively).

Conclusions:

In the current population, the DAPT score successfully stratified ischemic and bleeding risks, although the ischemic event rate was remarkably low even in high DS. Further studies would be warranted to evaluate the utility of prolonged DAPT guided by the DAPT score.

Frequency of Stent Thrombosis Risk at 5 Years in Women Versus Men With Zotarolimus-Eluting Compared With Sirolimus-Eluting Stent

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

Balancing Long-Term Risks of Ischemic and Bleeding Complications After Percutaneous Coronary Intervention With Drug-Eluting Stents

Although trials comparing antiplatelet strategies after percutaneous coronary intervention report average risks of bleeding and ischemia in a population, there is limited information to guide choices based on individual patient risks, particularly beyond 1 year after treatment. Patient-level data from Patient Related Outcomes With Endeavor vs Cypher Stenting Trial (PROTECT), a broadly inclusive trial enrolling 8,709 subjects treated with drug-eluting stents (sirolimus vs zotarolimus-eluting stent), and PROTECT US, a single-arm study including 1,018 subjects treated with a zotarolimus-eluting stent, were combined. The risk of ischemic events, cardiovascular death/non-periprocedural myocardial infarction (MI)/definite or probable stent thrombosis, and bleeding events, Global Use of Strategies to Open Occluded Arteries moderate or severe bleed, were predicted using logistic regression. At median follow-up of 4.1 years, major bleeding occurred in 260 subjects (2.8%) and ischemic events in 595 (6.3%). Multivariate predictors of bleeding were older age, smoking, diabetes mellitus, congestive heart failure, and chronic kidney disease (all p <0.05). Ischemic events shared all the same predictors with bleeding events and gender, body mass index, previous MI, previous coronary artery bypass graft surgery, ST-segment elevation MI on presentation, stent length, and sirolimus-eluting stent use (all p <0.05). Within individual subjects, bleeding and ischemic risks were strongly correlated; 97% of subjects had a greater risk of ischemic events than bleeding. In conclusion, individual patient risks of ischemia and bleeding are related to many common risk factors, yet the predicted risks of ischemic events are greater than those of major bleeding in the large majority of patients in long-term follow-up.

Modifying effect of dual antiplatelet therapy on incidence of stent thrombosis according to implanted drug-eluting stent type

AIM

To investigate the putative modifying effect of dual antiplatelet therapy (DAPT) use on the incidence of stent thrombosis at 3 years in patients randomized to Endeavor zotarolimus-eluting stent (E-ZES) or Cypher sirolimus-eluting stent (C-SES).

METHODS AND RESULTS

Of 8709 patients in PROTECT, 4357 were randomized to E-ZES and 4352 to C-SES. Aspirin was to be given indefinitely, and clopidogrel/ticlopidine for ≥ 3 months or up to 12 months after implantation. Main outcome measures were definite or probable stent thrombosis at 3 years. Multivariable Cox regression analysis was applied, with stent type, DAPT, and their interaction as the main outcome determinants. Dual antiplatelet therapy adherence remained the same in the E-ZES and C-SES groups (79.6% at 1 year, 32.8% at 2 years, and 21.6% at 3 years). We observed a statistically significant (P = 0.0052) heterogeneity in treatment effect of stent type in relation to DAPT. In the absence of DAPT, stent thrombosis was lower with E-ZES vs. C-SES (adjusted hazard ratio 0.38, 95% confidence interval 0.19, 0.75; P = 0.0056). In the presence of DAPT, no difference was found (1.18; 0.79, 1.77; P = 0.43).

CONCLUSION

A strong interaction was observed between drug-eluting stent type and DAPT use, most likely prompted by the vascular healing response induced by the implanted DES system. These results suggest that the incidence of stent thrombosis in DES trials should not be evaluated independently of DAPT use, and the optimal duration of DAPT will likely depend upon stent type (Clinicaltrials.gov number NCT00476957).

Optimized duration of clopidogrel therapy following treatment with the Endeavor zotarolimus-eluting stent in real-world clinical practice (OPTIMIZE) trial: rationale and design of a large-scale, randomized, multicenter study

BACKGROUND

Current recommendations for antithrombotic therapy after drug-eluting stent (DES) implantation include prolonged dual antiplatelet therapy (DAPT) with aspirin and clopidogrel ≥12 months. However, the impact of such a regimen for all patients receiving any DES system remains unclear based on scientific evidence available to date. Also, several other shortcomings have been identified with prolonged DAPT, including bleeding complications, compliance, and cost. The second-generation Endeavor zotarolimus-eluting stent (E-ZES) has demonstrated efficacy and safety, despite short duration DAPT (3 months) in the majority of studies. Still, the safety and clinical impact of short-term DAPT with E-ZES in the real world is yet to be determined.

METHODS

The OPTIMIZE trial is a large, prospective, multicenter, randomized (1:1) non-inferiority clinical evaluation of short-term (3 months) vs long-term (12-months) DAPT in patients undergoing E-ZES implantation in daily clinical practice. Overall, 3,120 patients were enrolled at 33 clinical sites in Brazil. The primary composite endpoint is death (any cause), myocardial infarction, cerebral vascular accident, and major bleeding at 12-month clinical follow-up post-index procedure.

CONCLUSIONS

The OPTIMIZE clinical trial will determine the clinical implications of DAPT duration with the second generation E-ZES in real-world patients undergoing percutaneous coronary intervention.

Stent thrombosis and major clinical events at 3 years after zotarolimus-eluting or sirolimus-eluting coronary stent implantation: a randomised, multicentre, open-label, controlled trial

BACKGROUND

We sought to compare the long-term safety of two devices with different antiproliferative properties: the Endeavor zotarolimus-eluting stent (E-ZES; Medtronic, Inc) and the Cypher sirolimus-eluting stent (C-SES; Cordis, Johnson & Johnson) in a broad group of patients and lesions.

METHODS

Between May 21, 2007 and Dec 22, 2008, we recruited 8791 patients from 36 recruiting countries to participate in this open-label, multicentre, randomised, superiority trial. Eligible patients were those aged 18 years or older undergoing elective, unplanned, or emergency procedures in native coronary arteries. Patients were randomly assigned to either receive E-ZES and C-SES (ratio 1:1). Randomisation was stratified per centre with varying block sizes of four, six, or eight patients, and concealed with a central telephone-based or web-based allocation service. The primary outcome was definite or probable stent thrombosis at 3 years and was analysed by intention to treat. Patients and investigators were aware of treatment assignment. This trial is registered with ClinicalTrials.gov, number NCT00476957.

FINDINGS

PROTECT randomised 8791 patients, of whom 8709 provided consent to participate and were eligible: 4357 were allocated to the E-ZES group and 4352 patients to the C-SES group. At 3 years, rates of definite or probable stent thrombosis did not differ between groups (1·4% for E-ZES [predicted: 1·5%] vs 1·8% [predicted: 2·5%] for C-SES; hazard ratio [HR] 0·81, 95% CI 0·58-1·14, p=0·22). Dual antiplatelet therapy was used in 8402 (96%) patients at discharge, 7456 (88%) at 1 year, 3041 (37%) at 2 years, and 2364 (30%) at 3 years.

INTERPRETATION

No evidence of superiority of E-ZES compared with C-SES in definite or probable stent thrombosis rates was noted at 3 years. Time analysis suggests a difference in definite or probable stent thrombosis between groups is emerging over time, and a longer follow-up is therefore needed given the clinical relevance of stent thrombosis.

FUNDING

Medtronic, Inc.

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.

Second- and third-generation drug-eluting coronary stents: progress and safety

Drug-eluting stents (DES) have revolutionized the treatment of coronary artery disease by reducing the rate of in-stent restenosis from 20-40% with bare-metal stent (BMS) to 6-8% with DES. However, with widespread use of DES, safety concerns have risen due to the observation of late stent thrombosis. With this in mind and better understanding of mechanism and pathophysiology of stent thrombosis, the technological platform, especially innovative anti-restenotic agents, polymeric coatings, and stent platforms, improved with newer DES. Two second-generation DES, the Endeavor zotarolimus-eluting stent (ZES) and the Xience-V everolimus-eluting stent (EES), have provided promising results in both randomized controlled trials (SPIRIT and ENDEAVOR) and registries (E-Five, COMPARE) compared with bare-metal stents (BMS) and first-generation DES. Newer third-generation stent technology, especially biodegradable polymers, polymer-free stents, and biodegradable stents on the basis of poly-L-lactide (PLLA) or magnesium, has been evaluated in preclinical and initial clinical trials. However, despite encouraging initial results, long-term data of large-scale randomized trials as well as registries comparing them to currently approved first- and second-generation DES are still lacking.

Drug-eluting coronary stents - focus on improved patient outcomes

The development of stent has been a major advance in the treatment of obstructive coronary artery disease since the introduction of balloon angioplasty. Subsequently, neointimal hyperplasia within the stent leading to in-stent restenosis emerged as a major obstacle in long-term success of percutaneous coronary intervention. Recent introduction of drug-eluting stents is a major breakthrough to tackle this problem. This review article summarizes stent technology, reviews progress of drug-eluting stents and discusses quality of life, patient satisfaction, and acceptability of percutaneous coronary intervention.

Current and future drug-eluting coronary stent technology

Despite the impressive benefits obtained following the introduction of the drug-eluting stent, safety concerns have been raised over their long-term safety with particular regard to stent thrombosis. Various mechanisms such as delayed endothelialization, local hypersensitivity and endothelial dysfunction owing to the durable polymer coating and/or the drug itself have been suggested as possible causes of this phenomenon. Therefore, to address these concerns, a newer-generation of drug-eluting stents has been developed and they are currently undergoing preclinical and clinical evaluation in order to increase both the safety and biocompatibility by optimizing the three major components of drug-eluting stents: the stent platform, the polymer and the drug. This article critically reviews the key clinical trials and the current status of these new coronary devices as well as preventing future perspectives for their continued development.

Three-year clinical outcome with the Endeavor™ zotarolimus-eluting stent in primary percutaneous coronary intervention for ST elevation myocardial infarction: the Endeavor™ primary PCI study (E-PPCI)

Primary percutaneous coronary intervention (PPCI) is superior to thrombolysis in STEMI (ST segment elevation myocardial infarction) patients. Data on late stent thrombosis (ST) have raised concerns regarding the use of drug-eluting stents during PPCI. We report the first 3-year clinical evaluation of the zotarolimus-eluting stent (ZES) in patients undergoing PPCI for STEMI, a single-center, prospective cohort study of consecutive patients admitted with STEMI. All underwent PPCI within 12 hours of symptoms; each received one or more ZES in one or more target lesions. All patients received aspirin 300 mg, clopidogrel 600 mg, abciximab, and unfractionated heparin. A total of 102 STEMI patients (76 male, mean 62 years) received 162 ZES (mean 1.6 stents/patient). Median call-to-balloon time was 123 (102-152) minutes. Thirty-day combined major adverse cardiovascular event (MACE) rate was 3.9% (n = 4). Subacute ST occurred in 2 patients (1.96%). Combined MACE rates at 12 months and 3 years were 7.8% (n = 8) and 13.7% (n = 14). Late ST occurred in 1 patient (1%) with no occurrence of very late ST. This is the first 3-year report of the use of the ZES in an unselected, consecutive PPCI population. Overall 3-year incidence of MACE and target lesion revascularization (5.9%) was low, and was comparable to that seen with sirolimus- and paclitaxel-eluting stents in randomized controlled trials. At 3 years there was no occurrence of very late ST.

Glycogen synthase kinase 3 beta positively regulates Notch signaling in vascular smooth muscle cells: role in cell proliferation and survival

The role of glycogen synthase kinase 3 beta (GSK-3β) in modulating Notch control of vascular smooth muscle cell (vSMC) growth (proliferation and apoptosis) was examined in vitro under varying conditions of cyclic strain and validated in vivo following changes in medial tension and stress. Modulation of GSK-3β in vSMC following ectopic expression of constitutively active GSK-3β, siRNA knockdown and pharmacological inhibition with SB-216763 demonstrated that GSK-3β positively regulates Notch intracellular domain expression, CBF-1/RBP-Jκ transactivation and downstream target gene mRNA levels, while concomitantly promoting vSMC proliferation and inhibiting apoptosis. In contrast, inhibition of GSK-3β attenuated Notch signaling and decreased vSMC proliferation and survival. Exposure of vSMC to cyclic strain environments in vitro using both a Flexercell™ Tension system and a novel Sylgard™ phantom vessel following bare metal stent implantation revealed that cyclic strain inhibits GSK-3β activity independent of p42/p44 MAPK and p38 activation concomitant with reduced Notch signaling and decreased vSMC proliferation and survival. Exposure of vSMC to changes in medial strain microenvironments in vivo following carotid artery ligation revealed that enhanced GSK-3β activity was predominantly localized to medial and neointimal vSMC concomitant with increased Notch signaling, proliferating nuclear antigen and decreased Bax expression, respectively, as vascular remodeling progressed. GSK-3β is an important modulator of Notch signaling leading to altered vSMC cell growth where low strain/tension microenvironments prevail.

Long-term clinical outcomes with zotarolimus-eluting versus bare-metal coronary stents

OBJECTIVES

This study sought to evaluate the long-term safety of the zotarolimus-eluting stent (ZES) using a pooled analysis of pivotal trials.

BACKGROUND

Drug-eluting stents, compared with bare-metal stents (BMS), have reduced restenosis; however, individual trials of these stents have not had sufficient power to ascertain long-term safety.

METHODS

We combined patient level data from 6 prospective randomized single-arm multicenter trials involving 2,132 patients treated with ZES and 596 patients treated with a BMS control. The median follow-up was 4.1 years, with 5-year follow-up completed in 1,256 patients (97% of those eligible). The recommended minimum duration of dual antiplatelet therapy in these studies was 3 to 6 months regardless of stent type. An independent events committee adjudicated all events. The 2 treatment groups were compared after adjustment for between trial variation and for individual patient clinical and angiographic characteristics by propensity score.

RESULTS

The cumulative incidence of adverse events at 5 years for ZES and BMS were: death: 5.9% versus 7.6% (adjusted hazard ratio: 0.81, p = 0.34), cardiac death: 2.4 versus 3.7% (0.83, p = 0.57), myocardial infarction: 3.4 versus 4.8% (0.77, p = 0.37), target lesion revascularization: 7.0% vs. 16.5% (0.42, p < 0.001), stent thrombosis (definite or probable): 0.8 versus 1.7% (0.50, p = 0.21). After adjustment for variation in study and patient characteristics, there were no significant differences in stent thrombosis or the clinical safety event rates at 5 years between ZES and BMS.

CONCLUSIONS

Over 5 years, there was no increased risk of death, myocardial infarction, or stent thrombosis, and there was a benefit of prevention of repeat revascularization procedures in ZES compared with BMS.

Long-term follow-up of the randomised controlled trial to evaluate the safety and efficacy of the zotarolimus-eluting driver coronary stent in de novo native coronary artery lesions: five year outcomes in the ENDEAVOR II study

AIMS

We report here the final 5-year follow-up results from the ENDEAVOR II trial, which was the first randomised trial evaluating the Endeavor(tm) zotarolimus-eluting stent (ZES) compared with a bare metal stent (BMS) in patients with single, de novo coronary artery lesions.

METHODS AND RESULTS

Eligible patients were randomised 1:1 to receive ZES or BMS and were followed by telephone or clinic visit up to five years. We evaluated TVF and its components (target vessel revascularisation [TVR], Q-wave or non Q-wave myocardial infarction, or cardiac death attributed to the target vessel) at five years. Additionally, we report rates of MACE, TLR, and stent thrombosis (protocol- and ARC-defined) through five years. ENDEAVOR II enrolled 1,197 patients (598 ZES, 599 BMS). At five years of follow-up, the rates of TVF (15.4% vs 24.4%), TVR (10.7% vs 20.1%), MACE (15.4% vs 24.6%), and TLR (7.5% vs 16.3%) remained significantly lower in ZES patients compared with BMS patients. ARC definite and probable very late (>1 year) stent thrombosis remained low (0.2% ZES and 0.3% BMS) through five years.

CONCLUSIONS

After five years of follow-up, ZES demonstrated significantly improved clinical outcomes with sustained safety compared with BMS in patients with obstructive coronary artery disease.

Improved late clinical safety with zotarolimus-eluting stents compared with paclitaxel-eluting stents in patients with de novo coronary lesions: 3-year follow-up from the ENDEAVOR IV (Randomized Comparison of Zotarolimus- and Paclitaxel-Eluting Stents in Patients With Coronary Artery Disease) trial

OBJECTIVES

The increased frequency of very late (>1 year) stent thrombosis (VLST) has raised concerns with regard to the safety of sirolimus-eluting stents and paclitaxel-eluting stents (PES).

BACKGROUND

Experimental and preliminary clinical findings with the zotarolimus-eluting stent (ZES) have suggested a favorable safety profile.

METHODS

The ENDEAVOR IV (Randomized Comparison of Zotarolimus- and Paclitaxel-Eluting Stents in Patients With Coronary Artery Disease) trial is a single-blind randomized ZES versus PES clinical trial in 1,548 patients with de novo native coronary lesions; the primary end point-9-month target vessel failure-was previously reported, annual clinical follow-up is planned for 5 years, and this report describes the 3-year outcomes.

RESULTS

The ZES compared with PES reduced target vessel failure (12.3% vs. 15.9%, hazard ratio [HR]: 0.76, 95% confidence interval [CI]: 0.58 to 1.00, p = 0.049), myocardial infarctions (MI) (2.1% vs. 4.9%, HR: 0.44, 95% CI: 0.25 to 0.80, p = 0.005), and cardiac death plus MI (3.6% vs. 7.1%, HR: 0.52, 95% CI 0.32 to 0.82, p = 0.004). Although the overall 3-year rate of Academic Research Consortium definite/probable stent thrombosis did not differ significantly (1.1% vs. 1.7%, HR: 0.67, 95% CI 0.28 to 1.64, p = 0.380), VLST (between 1 and 3 years) was significantly reduced in ZES patients (1 event vs. 11 events; 0.1% vs. 1.6%, HR: 0.09, 95% CI: 0.01 to 0.71, p = 0.004). Ischemia-driven target lesion revascularization at 3 years was similar with ZES versus PES (6.5% vs. 6.1%, HR: 1.10, 95% CI: 0.73 to 1.65, p = 0.662).

CONCLUSIONS

Three-year follow-up results from the ENDEAVOR IV trial indicate similar antirestenosis efficacy but improved clinical safety associated with ZES compared with PES, due to significantly fewer peri-procedural and remote MIs associated with fewer VLST events. (A Randomized, Controlled Trial of the Medtronic Endeavor Drug [ABT-578] Eluting Coronary Stent System Versus the Taxus Paclitaxel-Eluting Coronary Stent System in De Novo Native Coronary Artery Lesions; NCT00217269).

Comparison of zotarolimus-eluting stents with sirolimus- and paclitaxel-eluting stents for coronary revascularization: the ZEST (comparison of the efficacy and safety of zotarolimus-eluting stent with sirolimus-eluting and paclitaxel-eluting stent for coronary lesions) randomized trial

OBJECTIVES

The aim of this study was to evaluate the relative efficacy and safety of zotarolimus-eluting stents (ZES) in comparison with the established and widely used sirolimus- (SES) and paclitaxel-eluting stents (PES) in routine clinical practice.

BACKGROUND

Whether ZES might provide similar clinical and angiographic outcomes in a broad spectrum of patients compared with SES or PES is undetermined.

METHODS

We performed a single-blind, multicenter, prospectively randomized trial to compare ZES with SES and PES in 2,645 patients undergoing percutaneous coronary intervention. The primary end point was a composite of major adverse cardiac events (MACE) (death, myocardial infarction, and ischemia-driven target vessel revascularization) at 12 months. A noninferiority comparison (ZES vs. SES) and a superiority comparison (ZES vs. PES) were performed for the primary end point.

RESULTS

Baseline clinical and angiographic characteristics were similar in the 3 groups. At 12 months, the ZES group showed noninferior rates of MACE compared with the SES group (10.2% vs. 8.3%, p for noninferiority = 0.01, p for superiority = 0.17) and significantly fewer MACE than the PES group (10.2% vs. 14.1%, p for superiority = 0.01). The incidence of death or myocardial infarction was similar among the groups (ZES vs. SES vs. PES, 5.8% vs. 6.9% vs. 7.6%, respectively, p = 0.31). The incidence of stent thrombosis was significantly lower in the SES group (ZES vs. SES vs. PES, 0.7% vs. 0% vs. 0.8%, respectively, p = 0.02).

CONCLUSIONS

In this large-scale, practical randomized trial, the use of ZES resulted in similar rates of MACE compared with SES and in fewer MACE compared with PES at 12 months. (Comparison of the Efficacy and the Safety of Zotarolimus-Eluting Stent Versus Sirolimus-Eluting Stent and PacliTaxel-Eluting Stent for Coronary Lesions; NCT00418067).

Efficacy and safety of zotarolimus-eluting and sirolimus-eluting coronary stents in routine clinical care (SORT OUT III): a randomised controlled superiority trial

BACKGROUND

In low-risk patients, the zotarolimus-eluting stent has been shown to reduce rates of restenosis without increasing the risk of stent thrombosis. We compared the efficacy and safety of the zotarolimus-eluting stent versus the sirolimus-eluting stent in patients with coronary artery disease who were receiving routine clinical care with no direct follow-up.

METHODS

We did a single-blind, all-comer superiority trial in adult patients with chronic stable coronary artery disease or acute coronary syndromes, and at least one target lesion. Patients were treated at one of five percutaneous coronary intervention centres between January, 2006, and August, 2007. Computer-generated block randomisation and a telephone allocation service were used to randomly assign patients to receive the zotarolimus-eluting or the sirolimus-eluting stent. Data for follow-up were obtained from national Danish administrative and health-care registries. The primary endpoint was a composite of major adverse cardiac events within 9 months: cardiac death, myocardial infarction, and target vessel revascularisation. Intention-to-treat analyses were done at 9-month and 18-month follow-up. This trial is registered with ClinicalTrials.gov, number NCT00660478.

FINDINGS

1162 patients (1619 lesions) were assigned to receive the zotarolimus-eluting stent, and 1170 patients (1611 lesions) to receive the sirolimus-eluting stent. 67 patients (72 lesions) had stent failure, and six patients were lost to follow-up. All randomly assigned patients were included in analyses at 9-month follow-up; 2200 patients (94%) had completed 18-month follow-up by the time of our assessment. At 9 months, the primary endpoint had occurred in a higher proportion of patients treated with the zotarolimus-eluting stent than in those treated with the sirolimus-eluting stent (72 [6%] vs 34 [3%]; HR 2.15, 95% CI 1.43-3.23; p=0.0002). At 18-month follow-up, this difference was sustained (113 [10%] vs 53 [5%]; 2.19, 1.58-3.04; p<0.0001). For patients receiving the zotarolimus-eluting stent and those receiving the sirolimus-eluting stent, all cause-mortality was similar at 9-month follow-up (25 [2%] vs 18 [2%]; 1.40, 0.76-2.56; p=0.28), but was significantly different at 18-month follow-up (51 [4%] vs 32 [3%]; 1.61, 1.03-2.50; p=0.035).

INTERPRETATION

The sirolimus-eluting stent is superior to the zotarolimus-eluting stent for patients receiving routine clinical care.

FUNDING

Cordis and Medtronic.

The molecular mechanisms of congenital hypofibrinogenaemia

Congenital hypofibrinogenaemia is characterized by abnormally low levels of fibrinogen and is usually caused by heterozygous mutations in the fibrinogen chain genes (alpha, beta and gamma). However, it does not usually result in a clinically significant condition unless inherited in a homozygous or compound heterozygous state, where it results in a severe bleeding disorder, afibrinogenaemia. Various protein and expression studies have improved our understanding of how mutations causing hypo- and afibrinogenaemia affect secretion of the mature fibrinogen molecule from the hepatocyte. Some mutations can perturb chain assembly as in the gamma153 Cys-->Arg case, while others such as the Bbeta Leu-->Arg and the Bbeta414 Gly-->Ser mutations allow intracellular hexamer assembly but inhibit protein secretion. An interesting group of mutations, such as gamma284 Gly-->Arg and gamma375 Arg-->Trp, not only cause hypofibrinogenaemia but are also associated with liver disease. The nonexpression of these variant chains in plasma fibrinogen is due to retention in the endoplasmic reticulum, which in turn leads to hypofibrinogenaemia.