From bare metal to barely anything: an update on coronary stenting

Rationale and design of the PARTHENOPE trial: A two-by-two factorial comparison of polymer-free vs biodegradable-polymer drug-eluting stents and personalized vs standard duration of dual antiplatelet therapy in all-comers undergoing PCI

BACKGROUND

Over the past few decades, percutaneous coronary intervention (PCI) has undergone significant advancements as a result of the combination of device-based and drug-based therapies. These iterations have led to the development of polymer-free drug-eluting stents. However, there is a scarcity of data regarding their clinical performance. Furthermore, while various risk scores have been proposed to determine the optimal duration of dual antiplatelet therapy (DAPT), none of them have undergone prospective validation within the context of randomized trials.

DESIGN

The PARTHENOPE trial is a phase IV, prospective, randomized, multicenter, investigator-initiated, assessor-blind study being conducted at 14 centers in Italy (NCT04135989). It includes 2,107 all-comers patients with minimal exclusion criteria, randomly assigned in a 2-by-2 design to receive either the Cre8 amphilimus-eluting stent or the SYNERGY everolimus-eluting stent, along with either a personalized or standard duration of DAPT. Personalized DAPT duration is determined by the DAPT score, which accounts for both bleeding and ischemic risks. Patients with a DAPT score <2 (indicating higher bleeding than ischemic risk) receive DAPT for 3 or 6 months for chronic or acute coronary syndrome, respectively, while patients with a DAPT score ≥2 (indicating higher ischemic than bleeding risk) receive DAPT for 24 months. Patients in the standard DAPT group receive DAPT for 12 months. The trial aims to establish the noninferiority between stents with respect to a device-oriented composite end point of cardiovascular death, target-vessel myocardial infarction, or clinically-driven target-lesion revascularization at 12 months after PCI. Additionally, the trial aims to demonstrate the superiority of personalized DAPT compared to a standard approach with respect to a net clinical composite of all-cause death, any myocardial infarction, stroke, urgent target-vessel revascularization, or type 2 to 5 bleeding according to the Bleeding Academic Research Consortium criteria at 24-months after PCI.

SUMMARY

The PARTHENOPE trial is the largest randomized trial investigating the efficacy and safety of a polymer-free DES with a reservoir technology for drug-release and the first trial evaluating a personalized duration of DAPT based on the DAPT score. The study results will provide novel insights into the optimizing the use of drug-eluting stents and DAPT in patients undergoing PCI.

P2Y12 Inhibitors Monotherapy in Patients Undergoing Complex vs Non-Complex Percutaneous Coronary Intervention: A Meta-Analysis of Randomized Trials

BACKGROUND

Monotherapy with P2Y12 inhibitors (P2Y12i) is emerging as alternative strategy to dual antiplatelet therapy (DAPT) after percutaneous coronary intervention (PCI). However, early withdrawal of aspirin as part of P2Y12i monotherapy regimens may pose concerns in high-risk patients, such as those undergoing complex PCI. Our aim was to evaluate the efficacy and safety of P2Y12i monotherapy after a short course of DAPT (1-3-month) compared with standard DAPT (≥12-month) according to PCI complexity.

METHODS

We performed a meta-analysis of randomized trials using random effects models to combine hazard ratios (HRs) with 95% confidence intervals (CIs). Within-trial interactions were pooled to estimate heterogeneity between complex and noncomplex PCI strata. The study protocol was registered in the PROSPERO (CRD42021291027).

RESULTS

We identified 5 trials including 31,627 patients, of whom 8,328 (26.3%) underwent complex PCI. P2Y12i monotherapy compared with standard DAPT was associated with a similar risk of all-cause death, stent thrombosis, and stroke, with no evidence for interaction between complex and noncomplex PCI. We found heterogeneity in the treatment effect of P2Y12i monotherapy vs standard DAPT with respect to myocardial infarction (P-interaction = 0.027). Compared with standard DAPT, P2Y12i monotherapy decreased the risk of myocardial infarction in complex PCI (HR 0.77, 95%CI 0.60-0.99, P = .042), but not in noncomplex PCI patients (HR 1.09, 95%CI 0.90-1.30, P = .382). The risk of major bleeding was significantly reduced by P2Y12i monotherapy with a consistent treatment effect (P-interaction = 0.699) in both complex and noncomplex PCI strata.

CONCLUSIONS

Patients undergoing complex PCI may derive more benefit and less harm from P2Y12i monotherapy after early aspirin withdrawal compared with standard DAPT.

Individual Patient Data Meta-analysis of Drug-eluting Versus Bare-metal Stents for Percutaneous Coronary Intervention in Chronic Versus Acute Coronary Syndromes

New-generation drug-eluting stents (DES) strongly reduce restenosis and repeat revascularization compared with bare-metal stents (BMS) for percutaneous coronary intervention. There is residual uncertainty as to whether other prognostically relevant outcomes are affected by DES versus BMS concerning initial presentation (chronic coronary syndrome [CCS] vs acute coronary syndrome [ACS]). We performed an individual patient data meta-analysis of randomized trials comparing new-generation DES versus BMS (CRD42017060520). The primary outcome was the composite of cardiac death or myocardial infarction (MI). Outcomes were examined at maximum follow-up and with a 1-year landmark. Risk estimates are expressed as hazard ratio (HR) with 95% confidence interval (CI). A total of 22,319 patients were included across 14 trials; 7,691 patients (34.5%) with CCS and 14,628 patients (65.5%) with ACS. We found evidence that new-generation DES versus BMS consistently reduced the risk of cardiac death or MI in both patients with CCS (HR 0.83, 95% CI 0.70 to 0.98, p <0.001) and ACS (HR 0.83, 95% CI 0.75 to 0.92, p <0.001) (p-interaction = 0.931). This benefit was mainly driven by a similar reduction in the risk of MI (p-interaction = 0.898) for both subsets (HR_CCS 0.80, 95% CI 0.65 to 0.97; HR_ACS 0.79, 95% CI 0.70 to 0.89). In CCS and ACS, we found a time-dependent treatment effect, with the benefit from DES accumulating during 1-year follow-up, without offsetting effects after that. In conclusion, patients with CCS were slightly underrepresented in comparative clinical trials. Still, they benefited similarly to patients with ACS from new-generation DES instead of BMS with a sustained reduction of cardiac death or MI because of lower event rates within 1 year.

Ultrathin Struts Drug-Eluting Stents: A State-of-the-Art Review

New-generation drug-eluting stents (DESs) represent the standard of care for patients undergoing percutaneous coronary intervention (PCI). Recent iterations in DES technology have led to the development of newer stent platforms with a further reduction in strut thickness. This new DES class, known as ultrathin struts DESs, has struts thinner than 70 µm. The evidence base for these devices consists of observational data, large-scale meta-analyses, and randomized trials with long-term follow-up, which have been conducted to investigate the difference between ultrathin struts DESs and conventional new-generation DESs in a variety of clinical settings and lesion subsets. Ultrathin struts DESs may further improve the efficacy and safety profile of PCI by reducing the risk of target-lesion and target-vessel failures in comparison to new-generation DESs. In this article, we reviewed device characteristics and clinical data of the Orsiro (Biotronik, Bülach, Switzerland), Coroflex ISAR (B. Braun Melsungen, Germany), BioMime (Meril Life Sciences Pvt. Ltd., Gujarat, India), MiStent (MiCell Technologies, USA), and Supraflex (Sahajanand Medical Technologies, Surat, India) sirolimus-eluting stents.

Polymer Coating Integrity, Thrombogenicity and Computational Fluid Dynamics Analysis of Provisional Stenting Technique in the Left Main Bifurcation Setting: Insights from an In-Vitro Model

Currently, the provisional stenting technique is the gold standard in revascularization of lesions located in the left main (LM) bifurcation. The benefit of the routine kissing balloon technique (KBI) in bifurcation lesions is still debated, particularly following the single stent treatment. We compared the latest-generation drug-eluting stent (DES) with no side branch (SB) dilatation “keep it open” technique (KIO) vs. KBI technique vs. bifurcation dedicated drug-eluting stent (BD-DES) implantation. In vitro testing was performed under a static condition in bifurcation silicone vessel models. All the devices were implanted in accordance with the manufacturers’ recommendations. As a result, computational fluid dynamics (CFD) analysis demonstrated a statistically higher area of high shear rate in the KIO group when compared to KBI. Likewise, the maximal shear rate was higher in number in the KIO group. Floating strut count based on the OCT imaging was significantly higher in KIO than in KBI and BD-DES. Furthermore, according to OTC analysis, the thrombus area was numerically higher in both KIO and KBI than in the BD-DES. Scanning electron microscopy (SEM) analysis shows the highest degree of strut coating damage in the KBI group. This model demonstrated significant differences in CFD analysis at SB ostia with and without KBI optimization in the LM setting. The adoption of KBI was related to a meaningful reduction of flow disturbances in conventional DES and achieved results similar to BD-DES.

Arsenic trioxide activates yes-associated protein by lysophosphatidic acid metabolism to selectively induce apoptosis of vascular smooth muscle cells

Inhibition of vascular smooth muscle cells (VSMCs) proliferation without dysregulating endothelial cells (ECs) may provide an ideal therapy for in-stent restenosis. Due to its anti-proliferation effect on VSMCs and pro-endothelium effect, arsenic trioxide (ATO) has been used in a drug-eluting stent in a recent clinical trial. However, the underlying mechanism by which ATO achieves this effect has not been determined. In the present work, we showed that ATO induced apoptosis in VSMCs but not in ECs. Mechanistically, ATO achieved this through modulation of cellular metabolism to increase lysophosphatidic acid (LPA) in VSMCs, while LPA concentration was stable in ECs. The elevated LPA facilitated the nuclear accumulation and initiated the transcriptional function of Yes-associated protein (YAP) in VSMCs. YAP regulated the transcription of N6-Methyladenosine (m⁶A) modulators (Mettl14 and Wtap) to increase the m⁶A methylation levels of apoptosis-related genes to induce their high expression and exacerbate VSMCs apoptosis. On the other hand, YAP nuclear accumulation in ECs was not observed. Collectively, our data exhibited the molecular process involved in selective apoptosis of VSMCs induced by ATO.

Biodegradable vs. permanent polymer drug-eluting stents: the need for a new nomenclature to classify drug-eluting stent technology

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