ORAl iMmunosuppressive therapy to prevent in-Stent rEstenosiS (RAMSES) cooperation: A patient-level meta-analysis of randomized trials

In-Stent Restenosis

In-stent restenosis (ISR) remains a potential complication after percutaneous coronary intervention, even in the era of drug-eluting stents, and its treatment remains suboptimal. Neoatherosclerosis is an important component of the pathology of ISR and is accelerated in drug-eluting stents compared with bare-metal stents. Coronary angiography is the gold standard for evaluating the morphology of ISR, although computed tomography angiography is emerging as an alternative noninvasive modality to evaluate the presence of ISR. Drug-coated balloons and stent reimplantation are the current mainstays of treatment for ISR, and the choice of treatment should be based on clinical background and lesion morphology.

Adropin inhibits the phenotypic modulation and proliferation of vascular smooth muscle cells during neointimal hyperplasia by activating the AMPK/ACC signaling pathway

In-stent restenosis (ISR) remains an inevitable problem for some patients receiving drug-eluting stent (DES) implantation. Intimal hyperplasia is an important biological cause of ISR. It has been previously reported that adropin is a potentially protective factor in cardiovascular disease. Therefore, the present study investigated the function of adropin in inhibiting smooth muscle cell (SMC) phenotype modulation and proliferation, causing intimal hyperplasia. A total of 56 patients who visited the hospital consecutively (25 with ISR and 31 without ISR), who were followed up between April 2016 and March 2019, 1 year following DES, were analyzed to evaluate the association between in-stent neointimal volume and adropin serum levels. Rat aorta smooth muscle cells (RASMCs) were used to determine the effects of adropin on their phenotypic modulation and proliferation using western blot, MTT, PCR and immunofluorescence analyses. Adropin serum levels in the ISR group were significantly lower than those in the non-ISR group. Furthermore, linear regression analysis revealed that only adropin levels were negatively associated with neointimal volume in both groups. The overall adropin levels of the 56 patients and the percentages of neointimal volume revealed a strong negative association. In vitro, adropin suppressed angiotensin II (Ang II)-induced phenotypic modulation in RASMCs by restoring variations of osteopontin and α-smooth muscle actin. Furthermore, compared with the Ang II group, adropin markedly decreased the percentage of G₂/M-phase cells. Finally, adropin negatively regulated the phenotypic modulation and proliferation of RASMCs via the AMP-activated protein kinase/acetyl-CoA carboxylase (AMPK/ACC) signaling pathway. In conclusion, an independent, negative association was revealed between adropin and intimal hyperplasia; specifically, adropin inhibited the phenotypic modulation and proliferation of RASMCs by activating the AMPK/ACC signaling pathway. Therefore, adropin may be used as a potential predictor and therapeutic target for intimal hyperplasia and ISR.

Randomized comparison between bare-metal stent plus colchicine versus drug-eluting stent alone in prevention of clinical adverse events after percutaneous coronary intervention

The use of colchicine is associated with a significant reduction of cardiac adverse events in patients with coronary artery disease. Past small randomized trials with oral immunosuppressive or anti-inflammatory therapies have demonstrated a reduction of adverse clinical events after bare metal stent implantation. The potential role of adjunctive colchicine after bare-metal stent implantation, compared with drug-eluting stent alone, is unknown. The primary end point of the study will be to compare cost-effectiveness at 1 year of follow-up of coronary intervention with bare-metal stent implantation plus 1 mg of colchicine during 3 months versus percutaneous coronary intervention with drug-eluting stent implantation alone. ClinicalTrials.gov identifier: NCT04382443.

Increased incidence of serious late adverse events with drug-eluting stents when compared with coronary artery bypass surgery: a cause of concern

Percutaneous coronary intervention (PCI) and coronary artery bypass graft (CABG) in pre-drug-eluting stents (DESs) era, randomized trials and meta-analysis showed that the extension of coronary artery disease was not associated with a better survival with CABG, and only diabetic patients had an inferior survival with PCI. After the introduction of DES, we would expect a substantial improvement in PCI results compared with CABG, narrowing the gap between both revascularization strategies, However, on the contrary, most randomized studies between DES and CABG showed that rate of recurrences remained and there is an unexpected increased of late serious adverse events including spontaneous myocardial infarction and death. In this review, we try to described each of these problems and find out explanations for these new findings searching for potential solutions.

Restenosis of Drug-Eluting Stents

Despite on-going evolution and iteration of drug-eluting stent (DES) technology, the prevalence of in-stent restenosis (ISR) remains relatively unchanged, encompassing ≈10% of percutaneous coronary interventions. The mechanism of ISR is multifactorial, including biological, mechanical, patient, and operator-related factors. The main mechanical contributors are stent underexpansion or fracture, while biological factors include local inflammation leading to aggressive neointimal proliferation and late neoatherosclerosis. Intracoronary imaging is critical to identify the mechanism of ISR and tailor therapy accordingly. The presentation of DES-ISR is not benign and is challenging for optimal treatment. Among the proposed treatment modalities are scoring and high-pressure balloons, percutaneous coronary intervention with additional DES, atheroablative therapies by laser or mechanical atherectomy, drug-coated balloons, vascular brachytherapy, and surgical revascularization. We propose a new classification for ISR that differentiates among mechanical, biological, and mixed etiologies. Stratifying ISR by mechanism guides individualized treatment of DES-ISR to improve clinical outcomes. An algorithmic approach, guided by intracoronary imaging, for the treatment of DES-ISR, is recommended based on the specific cause of restenosis.

Cardiac Allograft Vasculopathy: The Enduring Enemy of Cardiac Transplantation

Cardiac allograft vasculopathy remains a major limiting factor in the long-term survival of the heart transplant recipient. Our understanding of its pathogenesis is continuously evolving as advances in imaging modalities have allowed a direct window into the natural history of the disease. Innovation in diagnostic modalities has spurred the proliferation of prognostic tools and biomarkers. And in parallel, pharmacological advances have emerged that have helped ameliorate the disease's progressive course.

One-Year Follow-Up Results From the Observational, Multicenter, Prospective, and Controlled Registry: The WALTZ All-Comers Study

The aim of this study was to evaluate 1-year follow-up results in an all “comers” population treated with a new cobalt chromium bare-metal stent (BMS) design. Since August 2016 to March 2017, 201 (9.7% of screening population) consecutive patients undergoing coronary stent implantation in 11 centers in Argentina were prospectively included in our registry. The inclusion criteria were multiple-vessel disease and/or unprotected left main disease, acute coronary syndromes (ACS) with at least one severe (⩾70%) stenosis in any of major epicardial vessel. In-stent restenosis, protected left main stenosis, or impossibility to receive dual-antiplatelet therapy was an exclusion criterion. Major adverse cardiac events (MACE) were the primary endpoint and included cardiac death, myocardial infarction (MI), and target lesion revascularization (TLR); also, all components of the primary endpoint were separately analyzed. Completeness of revascularization was analyzed as post hoc data using residual SYNTAX or ERACI risk scores. Demographic characteristics showed that 6.5% of patients were very elderly, 22.5% have diabetes, 47% have multiple-vessel disease, 67% have ACS, and 32% have ST elevation MI. At a mean of 376 ± 18.1 days of follow-up, MACE was observed in 10.4% of patients: death + MI + cardiovascular accident (CVA) in 3% (6 of 201) and cardiac death + MI + CVA in 1.5% (3 of 201). Residual ERACI score ⩽5 was associated with 98% of event-free survival (P < .04). In conclusion, this prospective, multicenter, and observational all-comers registry with this novel BMS design showed a low incidence of adverse events at 1 year mainly due to coronary restenosis.

In vivo delivery and long-term tissue retention of nano-encapsulated sirolimus using a novel porous balloon angioplasty system

AIMS

Among antirestenotic compounds, sirolimus displays a superior safety profile compared to paclitaxel, but its pharmacokinetic properties make it a challenging therapeutic candidate for single-time delivery. Herein we evaluate the feasibility of delivery, long-term retention and vascular effects of sirolimus nanoparticles delivered through a novel porous angioplasty balloon in normal porcine arteries and in a swine model of in-stent restenosis (ISR).

METHODS AND RESULTS

Sirolimus nanoparticle formulation was delivered via porous balloon angioplasty to 753 coronary artery segments for pharmacokinetic studies and 26 segments for biological effect of sirolimus delivery in different clinical scenarios (de novo [n=8], ISR [n=6] and following stent implantation [n=12]). Sirolimus coronary artery concentrations were above the target therapeutic level of 1 ng/mg after 26 days, and were >100-fold higher in coronary artery treatment sites than in distal myocardium and remote tissues at all time points. At 28 days, reduction in percent stenosis in formulation-treated sites compared to balloon angioplasty treatment was noted in all three clinical scenarios, with the largest effect seen in the de novo study.

CONCLUSIONS

Local coronary delivery of sirolimus nanoparticles in the porcine model using a novel porous balloon delivery system achieved therapeutic long-term intra-arterial drug levels without significant systemic residual exposure.