Platinum chromium everolimus-eluting stents for the treatment of (complex) coronary artery disease; from SYNERGY™ to the MEGATRON™

INTRODUCTION

The introduction of drug-eluting coronary stents (DES) into clinical practice in 2002 represented a major milestone in the treatment of obstructive coronary artery disease. Over the years, significant advances in polymer coating and in antiproliferative agent technology have further improved the safety and clinical performance of newer-generation DES.

AREAS COVERED

Development of platinum chromium (PtCr) alloys with high radial strength and high radiopacity have enabled the design of new, thin-strut, flexible, and highly trackable stent platforms, while simultaneously improving stent visibility. These advances have facilitated complex percutaneous treatment of a diverse population of patients in clinical practice. This review will provide an overview of the evolution in PtCr everolimus-eluting stents from PROMUS Element™ to SYNERGY™ to the recently introduced SYNERGY MEGATRON™. The clinical data will be summarized and put into perspective, especially focusing on the role of the SYNERGY™ and MEGATRON™ platforms in the treatment of complex coronary artery disease and high-risk patients.

EXPERT OPINION

The SYNERGY™ stent demonstrates favorable clinical efficacy and safety outcome data, and whilst the clinical data on MEGATRON™ are sparse, early experience is promising. The specific overexpansion capabilities, visibility, and radial strength of the MEGATRON™ are attractive features for complex coronary interventions.

Two-year outcomes after percutaneous coronary intervention with drug-eluting stents or bare-metal stents in elderly patients with coronary artery disease

OBJECTIVES

Report the results at 2 years of the patients included in the SENIOR trial.

BACKGROUND

Patients above 75 years of age represent a fast-growing population in the cathlab. In the SENIOR trial, patients treated by percutaneous coronary intervention (PCI) with drug eluting stent (DES) and a short duration of P2Y12 inhibitor (1 and 6 months for stable and unstable coronary syndromes, respectively) compared with bare metal stents (BMS) was associated with a 29% reduction in the rate of all-cause mortality, myocardial infarction (MI), stroke, and ischaemia-driven target lesion revascularization (ID-TLR) at 1 year. The results at 2 years are reported here.

METHODS AND RESULTS

We randomly assigned 1,200 patients (596[50%] to the DES group and 604[50%] to the BMS group). At 2 years, the composite endpoint of all-cause mortality, MI, stroke and ID-TLR had occurred in 116 (20%) patients in the DES group and 131 (22%) patients in the BMS group (RR 0.90 [95%CI 0.72-1.13], p = .37). IDTLR occurred in 14 (2%) patients in the DES group and 41 (7%) patients in the BMS group (RR 0.35 [95%CI 0.16-0.60], p = .0002). Major bleedings (BARC 3-5) occurred in 27(5%) patients in both groups (RR 1.00, [95%CI 0.58-1.75], p = .99). Stent thrombosis rates were low and similar between DES and BMS (0.8 vs 1.3%, (RR 0.52 [95%CI 0.01-1.95], p = .27).

CONCLUSION

Among elderly PCI patients, a strategy combining a DES together with a short duration of DAPT is associated with a reduction in revascularization up to 2 years compared with BMS with very few late events and without any increased in bleeding complications or stent thrombosis.

1-Year Safety of 3-Month Dual Antiplatelet Therapy Followed by Aspirin or P2Y12 Receptor Inhibitor Monotherapy Using a Bioabsorbable Polymer Sirolimus-Eluting Stent

BACKGROUND

This study evaluated the safety of 3-month dual antiplatelet therapy (DAPT) after implantation of a bioresorbable polymer sirolimus-eluting stent (BP-SES) and compared P2Y12inhibitor with aspirin monotherapy 3 months after DAPT.

METHODS AND RESULTS

Patients who underwent percutaneous coronary intervention using BP-SES were enrolled and followed for 1 year. Patients with a history of stent thrombosis were excluded. The primary endpoint was a composite of all-cause death, myocardial infarction, stroke (ischemic and hemorrhagic), definite or probable stent thrombosis, and severe bleeding at 12 months. The BP-SES arm of the CENTURY II trial was used as a conventional DAPT group for comparison. After DAPT, patients were maintained on either aspirin (n=846) or a P2Y12inhibitor (n=674 patients).In all, 1,695 patients were enrolled in the study across 65 centers. The primary endpoint occurred in 4.3% of patients at 1 year. After propensity score adjustment, the incidence of the primary endpoint was not inferior in those receiving DAPT for 3 months compared with conventional DAPT (5.5%; Pnon-inferiority<0.0001). The incidence of the primary endpoint and severe bleeding did not differ between the aspirin and P2Y12inhibitor monotherapy groups.

CONCLUSIONS

After adjustment, 3-month DAPT was not inferior to longer DAPT after BP-SES implantation in terms of net adverse clinical events. There was no difference in bleeding and thrombotic events between P2Y12inhibitor and aspirin monotherapy after 3 months DAPT.

Cancer treatment resumption in patients with new-generation drug-eluting stents

OBJECTIVE

Percutaneous coronary intervention (PCI) with new-generation drug-eluting stents (DESs) may provide survival benefits to the cancer population undergoing PCI by expediting cancer treatment due to improved safety profile. We aimed to assess the safety of starting or resuming cancer treatment within 6 months of DES placement. We also compared the impact of different DES types on the overall survival (OS) in cancer patients and to identify a safe threshold for dual antiplatelet therapy (DAPT) discontinuation.

METHODS

Cancer patients at our institution undergoing PCI with DES from December 2014 to June 2017 were included. Baseline demographics, DAPT duration, malignancy type, stage, and treatment were retrospectively analyzed. Univariate Cox regression was used to pinpoint baseline characteristics that correlated with OS. Survivorship was determined by Kaplan-Meier analysis, and the log-rank test was used to compare OS among DES types.

RESULTS

Seventy-five patients were included. Of these, 45 had biodegradable polymer DES (Synergy) and 30 patients had durable polymer DES (Resolute Integrity, Xience, Ion, or Promus). Mean duration of follow-up was 1367 ± 334 days. There were two minor bleeding complications. No statistically significant differences in OS were found among different stent brands. Discontinuation of aspirin, early P2Y12 inhibitor discontinuation, and advanced cancer were significantly associated with OS. DAPT discontinuation <6 months after PCI was not associated with stent thrombosis or in-stent restenosis. There were two major adverse cardiac events: one in-stent restenosis while on DAPT for >12 months (attributed to radiation-induced heart disease) and one myocardial infarction and death. Of patients who resumed or started cancer treatment (chemotherapy, radiation therapy, or surgery) after PCI, all but one did so within 6 months of PCI, and most of them as early as 2 weeks.

CONCLUSION

Patients may resume cancer treatment <6 months after PCI. We suggest that DAPT may be safely interrupted as early as 6 months, but additional longitudinal studies are needed.

Cost-Effectiveness of Drug-Eluting Stents in Elderly Patients With Coronary Artery Disease: The SENIOR Trial

BACKGROUND

Elderly patients receive bare metal stents instead of drug-eluting stents (DES) to shorten the duration of dual antiplatelet therapy (DAPT). The SENIOR trial compared outcomes between these 2 types of stents combined with a short duration of DAPT. A significant decrease in the number of patients with at least 1 major adverse cardiac and cerebrovascular event (MACCE) was noted in the DES group.

OBJECTIVES

The objective of this article was to perform an economic evaluation of the SENIOR trial.

METHODS

This evaluation was performed separately in 5 participating countries using pooled patient-level data from all study patients and country-specific unit costs and utility values. Costs, MACCEs, and quality-adjusted life-years (QALYs) were calculated in both arms at 1 year, and an incremental cost-effectiveness ratio was estimated. Uncertainty was explored by probabilistic bootstrapping.

RESULTS

A total of 1200 patients underwent randomization. The average total cost per patient was higher in the DES group. The number of MACCEs and average QALYs were not statistically different between the 2 groups. The 1-year incremental cost-effectiveness ratio for each country of reference ranged from €13 752 to €20 511/MACCE avoided and from €42 835 to €68 231/QALY gained. The scatter plots found a wide dispersion, reflecting a large uncertainty surrounding the results. But in each country studied, 90% of the bootstrap replications indicated a higher cost for greater effectiveness for the DES group. Assuming a willingness to pay of €50 000/QALY, there was between a 40% and 50% chance that the use of DES was cost-effective in 4 countries.

CONCLUSION

The use of DES instead of bare metal stents combined with a short duration of DAPT in elderly patients induced higher cost for greater effectiveness in each of the 5 countries studied.

Drug-eluting stents in elderly patients with coronary artery disease (SENIOR): a randomised single-blind trial

BACKGROUND

Elderly patients regularly receive bare-metal stents (BMS) instead of drug-eluting stents (DES) to shorten the duration of double antiplatelet therapy (DAPT). The aim of this study was to compare outcomes between these two types of stents with a short duration of DAPT in such patients.

METHODS

In this randomised single-blind trial, we recruited patients from 44 centres in nine countries. Patients were eligible if they were aged 75 years or older; had stable angina, silent ischaemia, or an acute coronary syndrome; and had at least one coronary artery with a stenosis of at least 70% (≥50% for the left main stem) deemed eligible for percutaneous coronary intervention (PCI). Exclusion criteria were indication for myocardial revascularisation by coronary artery bypass grafting; inability to tolerate, obtain, or comply with DAPT; requirement for additional surgery; non-cardiac comorbidities with a life expectancy of less than 1 year; previous haemorrhagic stroke; allergy to aspirin or P2Y₁₂ inhibitors; contraindication to P2Y₁₂ inhibitors; and silent ischaemia of less than 10% of the left myocardium with a fractional flow reserve of 0·80 or higher. After the intended duration of DAPT was recorded (1 month for patients with stable presentation and 6 months for those with unstable presentation), patients were randomly allocated (1:1) by a central computer system (blocking used with randomly selected block sizes [two, four, eight, or 16]; stratified by site and antiplatelet agent) to either a DES or similar BMS in a single-blind fashion (ie, patients were masked), but those assessing outcomes were masked. The primary outcome was to compare major adverse cardiac and cerebrovascular events (ie, a composite of all-cause mortality, myocardial infarction, stroke, or ischaemia-driven target lesion revascularisation) between groups at 1 year in the intention-to-treat population, assessed at 30 days, 180 days, and 1 year. This trial is registered with ClinicalTrials.gov, number NCT02099617.

FINDINGS

Between May 21, 2014, and April 16, 2016, we randomly assigned 1200 patients (596 [50%] to the DES group and 604 [50%] to the BMS group). The primary endpoint occurred in 68 (12%) patients in the DES group and 98 (16%) in the BMS group (relative risk [RR] 0·71 [95% CI 0·52-0·94]; p=0·02). Bleeding complications (26 [5%] in the DES group vs 29 [5%] in the BMS group; RR 0·90 [0·51-1·54]; p=0·68) and stent thrombosis (three [1%] vs eight [1%]; RR 0·38 [0·00-1·48]; p=0·13) at 1 year were infrequent in both groups.

INTERPRETATION

Among elderly patients who have PCI, a DES and a short duration of DAPT are better than BMS and a similar duration of DAPT with respect to the occurrence of all-cause mortality, myocardial infarction, stroke, and ischaemia-driven target lesion revascularisation. A strategy of combination of a DES to reduce the risk of subsequent repeat revascularisations with a short BMS-like DAPT regimen to reduce the risk of bleeding event is an attractive option for elderly patients who have PCI.

FUNDING

Boston Scientific.

Current State of Bioabsorbable Polymer-Coated Drug-Eluting Stents

Drug-eluting stents (DES) have been shown to significantly reduce clinical and angiographic restenosis compared to bare metal stents (BMS). The polymer coatings on DES elute antiproliferative drugs to inhibit intimal proliferation and prevent restenosis after stent implantation. Permanent polymers which do not degrade in vivo may increase the likelihood of stent-related delayed arterial healing or polymer hypersensitivity. In turn, these limitations may contribute to an increased risk of late clinical events. Intuitively, a polymer which degrades after completion of drug release, leaving an inert metal scaffold in place, may improve arterial healing by removing a chronic source of inflammation, neoatherosclerosis, and/or late thrombosis. In this way, a biodegradable polymer may reduce late ischemic events. Additionally, improved healing after stent implantation could reduce the requirement for long-term dual antiplatelet therapy and the associated risk of bleeding and cost. This review will focus on bioabsorbable polymer-coated DES currently being evaluated in clinical trials.

Expert Opinion Percutaneous Coronary Intervention in Older People: Does Age Make a Difference?

As many people are living longer, much older patients are now commonly being seen in clinical practice. The management of coronary disease in this group presents formidable challenges. We review the epidemiology of coronary disease in this population and report on the burden of comorbidity, influence of frailty, problems with polypharmacy, interactions and compliance for the older patient. We discuss the management of stable and acute coronary syndromes, the specific anatomical challenges of the older coronary artery, the outcomes of the limited number of trials involving older patients, and review the guidelines available.