Patient and lesion characteristics in late/very late stent thrombosis with everolimus-eluting stents from real-world adverse event reporting

Drug-Eluting, Bioresorbable Cardiovascular Stents─Challenges and Perspectives

Globally, the leading causes of natural death are attributed to coronary heart disease and type 1 and type 2 diabetes. High blood pressure levels, high cholesterol levels, smoking, and poor eating habits lead to the agglomeration of plaque in the arteries, reducing the blood flow. The implantation of devices used to unclog vessels, known as stents, sometimes results in a lack of irrigation due to the excessive proliferation of endothelial tissue within the blood vessels and is known as restenosis. The use of drug-eluting stents (DESs) to deliver antiproliferative drugs has led to the development of different encapsulation techniques. However, due to the potency of the drugs used in the initial stent designs, a chronic inflammatory reaction of the arterial wall known as thrombosis can cause a myocardial infarction (MI). One of the most promising drugs to reduce this risk is everolimus, which can be encapsulated in lipid systems for controlled release directly into the artery. This review aims to discuss the current status of stent design, fabrication, and functionalization. Variables such as the mechanical properties, metals and their alloys, drug encapsulation and controlled elution, and stent degradation are also addressed. Additionally, this review covers the use of polymeric surface coatings on stents and the recent advances in layer-by-layer coating and drug delivery. The advances in nanoencapsulation techniques such as liposomes and micro- and nanoemulsions and their functionalization in bioresorbable, drug-eluting stents are also highlighted.

Clinical significance of neoatherosclerosis observed at very late phase between 3 and 7 years after coronary stent implantation

BACKGROUND

Clinical significance of neoatherosclerosis (NA) observed at very late phase remains undetermined. We sought to investigate the association between NA observed by optical coherence tomography (OCT) 3-7 years after stenting and subsequent clinical outcomes.

METHODS

We investigated previously implanted stents without stent failure in the institutional OCT database at Tsuchiura Kyodo General Hospital. Qualitative and quantitative OCT analyses were performed. In patient-based analysis, major adverse cardiac events (MACE) included all-cause death, non-fatal myocardial infarction, and clinically driven revascularization. MACE-free survival rate was compared between patients with any stent showing NA (NA group) and those without NA (non-NA group). In stent-based analysis, the stent failure including target-lesion revascularization and stent thrombosis after the belated OCT examination were assessed.

RESULTS

A total of 187 patients with 308 stents undergoing belated OCT examination 3-7 years after implantation were investigated. Median duration from implantation to the belated OCT was 4.8 (3.8-5.8) years and NA was identified in 48 stents (15.6%) in 36 patients (19.3%). In patient-based analysis, during the median of 2.9 (2.1-3.6) years after belated OCT, MACE occurred in 9 patients (25.0%) with at least one stent showing NA (NA group) and 9 patients (6.0%) without NA (non-NA group) (p=0.002). Cox regression analysis revealed that NA was an independent predictor of MACE [hazard ratio (HR) 4.14 (1.58- 10.8), p=0.004]. In stent-based analysis, 7 stent failures were documented (stents with NA 10.0% vs. stents without NA 0.8%, p<0.01). NA was a significant predictor of stent failure [HR 9.17 (1.67- 50.3), p=0.011] at OCT examinations.

CONCLUSIONS

NA observed by OCT 3-7 years after implantation was associated with subsequent worse clinical outcomes in both patient-based and stent-based analysis.

Everolimus-eluting bioresorbable scaffolds and metallic stents in diabetic patients: a patient-level pooled analysis of the prospective ABSORB DM Benelux Study, TWENTE and DUTCH PEERS

Background

Several studies compared everolimus-eluting bioresorbable scaffolds (EE-BRS) with everolimus-eluting stents (EES), but only few assessed these devices in patients with diabetes mellitus.

Aim

To evaluate the safety and efficacy outcomes of all-comer patients with diabetes mellitus up to 2 years after treatment with EE-BRS or EES.

Methods

We performed a post hoc pooled analysis of patient-level data in diabetic patients who were treated with EE-BRS or EES in 3 prospective clinical trials: The ABSORB DM Benelux Study (NTR5447), TWENTE (NTR1256/NCT01066650) and DUTCH PEERS (NTR2413/NCT01331707). Primary endpoint of the analysis was target lesion failure (TLF): a composite of cardiac death, target vessel myocardial infarction or clinically driven target lesion revascularization. Secondary endpoints included major adverse cardiac events (MACE): a composite of all-cause death, any myocardial infarction or clinically driven target vessel revascularization, as well as definite or probable device thrombosis (ST).

Results

A total of 499 diabetic patients were assessed, of whom 150 received EE-BRS and 249 received EES. Total available follow-up was 222.6 patient years (PY) in the EE-BRS and 464.9 PY in the EES group. The adverse events rates were similar in both treatment groups for TLF (7.2 vs. 5.2 events per 100 PY, p = 0.39; adjusted hazard ratio (HR) = 1.48 (95% confidence interval (CI): 0.77–2.87), p = 0.24), MACE (9.1 vs. 8.3 per 100 PY, p = 0.83; adjusted HR = 1.23 (95% CI: 0.70–2.17), p = 0.47), and ST (0.9 vs. 0.6 per 100 PY, p > 0.99).

Conclusion

In this patient-level pooled analysis of patients with diabetes mellitus from 3 clinical trials, EE-BRS showed clinical outcomes that were quite similar to EES.

Independent Factors for In-Hospital Death Following Drug-Eluting Stent Thrombosis From the Japanese Adverse Event Report System

BACKGROUND

Stent thrombosis (ST) is a serious complication after drug-eluting stents (DES) implantation. To identify the risk factors of mortality following ST, we evaluated adverse event reports used for safety measures after approval.

METHODS AND RESULTS

Between July 2004 and August 2019, 2,887 ST case reports were submitted to the Pharmaceutical and Medical Device Agency. Reports of probable or possible ST (n=604), with insufficient data regarding in-hospital outcome or duration between procedure and ST occurrence (n=37) or duplicate reports (n=191) were excluded. Accordingly, 2,045 reports with definite ST were analyzed. Among the subjects, there were 286 in-hospital deaths (14.0%). Multivariate logistic regression analysis revealed that left main trunk (LMT) (odds ratio [OR]: 4.76, 95% confidence interval [CI]: 3.26-6.96), chronic heart failure (CHF) (OR: 2.88, 95% CI: 1.61-5.14), hemodialysis (OR: 2.69, 95% CI: 1.66-4.36), prior stroke (OR: 2.28, 95% CI: 1.15-4.51), over 70 years old (OR: 1.62, 95% CI: 1.22-2.16), and right coronary artery (OR: 0.41, 95% CI: 0.27-0.63) were independent factors for in-hospital death after DES-ST.

CONCLUSIONS

LMT, CHF, hemodialysis, prior stroke, and older age were independently associated with higher risk of in-hospital death following DES-ST. If target patients have these factors, maximum preventive strategies against ST occurrence, including adequate dual-antiplatelet therapy duration and optimal DES deployment procedures, are required.

Clinical outcomes after percutaneous coronary intervention for early versus late and very late stent thrombosis: a systematic review and meta-analysis

Whether the clinical outcomes of stent thrombosis (ST) are different when stratified by time of occurrence remains unclear. The objective of this study was to compare the short- and long-term clinical outcomes after percutaneous coronary intervention (PCI) for early stent thrombosis (EST) versus late stent thrombosis (LST) and very late stent thrombosis (VLST). We enrolled eligible studies searched from the main electronic databases (EMBASE, PubMed, Cochrane). The primary endpoints were in-hospital, 30-day, 1-year and long-term mortality. The secondary endpoints included recurrent stent thrombosis (RST) and target vessel/lesion revascularization (TVR/TLR) during hospitalization, at 30 days, at 1 year and at long-term follow-up. A total of 23 studies with 17,592 patients were included. Compared with mortality rates of the late and very late thrombosis (LST/VLST) group, in-hospital (P = 0.004), 30-day (P < 0.00001), 1-year (P < 0.00001) and long-term mortality rates (P = 0.04) were significantly higher in the EST group. The in-hospital TVR/TLR rates were similar between the EST group and the LST/VLST group. However, a higher trend in TVR/TLR rate at 30 days and a significantly higher TVR/TLR rate at 1 year (P = 0.002) as well as at long-term follow up (P = 0.009) were found in the EST group. EST patients also trended toward higher risk of RST in both short- and long-term follow-up than LST/VLST patients, although differences were not statistically significant. After PCI treatment, patients with EST have worse clinical outcomes in both short- and long-term follow-up than patients with LST/VLST. Further studies are warranted to determine the optimal treatment strategies for EST.

Comparison of post-stent irregular protrusion and subsequent neointimal characteristics between second- and third-generation drug-eluting stent implantation

BACKGROUND

Third-generation drug-eluting-stents (3rd DES) may improve coronary arterial healing and reduce neoatherosclerosis formation. We evaluated post-stent findings and subsequent vascular healing of 3rd DES by comparing to second-generation drug-eluting-stents (2nd DES) at intermediate-term follow-up using optical coherence tomography (OCT).

METHOD

We evaluated 170 patients with 170 lesions who underwent DES implantation (2nd DES, n = 98; 3rd DES, n = 72) and OCT-guided follow-up examination. After propensity score (PS) matching for baseline clinical characteristics, OCT findings from 56 pairs of patients with 2nd DES and 3rd DES implants were compared. Post-stent irregular protrusion (IP) was defined as the protrusion of material with an irregular surface into the lumen between the stent struts. Neoatheroscleosis was defined as neointima contained heterogeneous pattern, rupture, lipid-laden, thin-cap fibroatheroma, or calcification. The presence of peri-strut low-intensity area (PLIA) and in-stent neointimal tissue characteristics were also analyzed at 6- to 8-month follow-up.

RESULTS

There were no significant differences between the incidence of post-stent IP or neoatherosclerosis formation in the 2nd DES and the 3rd DES (45% vs. 38%, p = 0.44; 30% vs. 20%, p = 0.19, respectively). However, the incidences of PLIA and layered neointimal pattern, which indicate immature neointimal healing, were significantly lower in the 3rd DES compared to the 2nd DES (41% vs. 61%, p = 0.04; 2% vs. 11%, p = 0.04, respectively). As comparing intermediate-term follow-up OCT neointimal findings in patients with IP between 2nd DES and 3rd DES, most neointima tended to have a homogeneous pattern (95% versus 76%, p = 0.06) in the 3rd DES than in the 2nd DES.

CONCLUSIONS

The incidence of post-stent IP and subsequent neoatherosclerosis formation at intermediate-term follow-up after stent implantation were similar between patients with 2nd DES and 3rd DES, however, vascular healing might be favorable when using 3rd DES.