Angioscopic Comparison of Early- and Mid-Term Vascular Responses Following Treatment of ST-Elevation Acute Myocardial Infarction With Biodegradable vs. Durable Polymer Everolimus-Eluting Stents - A Prespecified Subanalysis of the MECHANISM AMI RCT

BACKGROUND

The vessel healing process after implantation of biodegradable polymer (BP) and durable polymer (DP) everolimus-eluting stent (EES) in ST-elevation myocardial infarction (STEMI) lesions remains unclear.

METHODS AND RESULTS

We conducted a multicenter prospective randomized controlled trial to compare early (2 weeks) and mid-term (12 months) vascular responses after implantation of BP-EES vs. DP-EES in STEMI patients. In this prespecified subanalysis, serial coronary angioscopy (CAS) analysis was performed in 15 stents in the BP-EES arm (n=10 patients) and 14 stents in the DP-EES arm (n=10 patients). At the 2-week follow-up, there was no significant difference in the estimated marginal means of the neointimal coverage grade (primary endpoint) between the 2 arms (mean [±SE] 0.00±0.00 in both arms; P>0.999). There were no significant differences between the BP-EES and DP-EES groups in the yellow color grade (1.046±0.106 vs. 0.844±0.114, respectively; P=0.201) or the presence of thrombus (77.8% vs. 88.8%, respectively; P=0.205). At 12 months, competent strut coverage, defined as yellow color grade ≤1, no thrombus, and a neointimal coverage grade ≥1 was achieved more frequently in the BP-EES than DP-EES arm (85.2% vs. 53.1%; adjusted odds ratio 2.11 [95% confidence interval 1.26-3.53]; P=0.023).

CONCLUSIONS

Neointimal coverage 2 weeks after implantation of BP-EES and DP-EES in STEMI lesions was comparable on CAS evaluation. However, at 1 year, BP-EES was independently associated with competent strut coverage.

Prevalence and Impact of Neoatherosclerosis on Clinical Outcomes After Percutaneous Treatment of Second-Generation Drug-Eluting Stent Restenosis

BACKGROUND

Clinical and morphological factors associated with lipidic versus calcified neoatherosclerosis within second-generation drug-eluting stents and the impact of lipidic versus calcified neoatherosclerosis on long-term outcomes after repeat intervention have not been well studied.

METHODS

A total of 512 patients undergoing optical coherence tomography before percutaneous coronary intervention for second-generation drug-eluting stents in-stent restenosis were included. Neoatherosclerosis was defined as lipidic or calcified neointimal hyperplasia in ≥3 consecutive frames or ruptured lipidic neointimal hyperplasia. The primary outcome was target lesion failure (cardiac death, target vessel myocardial infarction, definite stent thrombosis, or clinically driven target lesion revascularization).

RESULTS

The overall prevalence of neoatherosclerosis was 28.5% (146/512): 56.8% lipidic, 30.8% calcified, and 12.3% both lipidic and calcific. The prevalence increased as a function of time from stent implantation: 20% at 1 to 3 years, 30% at 3 to 7 years, and 75% >7 years. Renal insufficiency, poor lipid profile, and time from stent implantation were associated with lipidic neoatherosclerosis, whereas severe renal insufficiency, female sex, and time from stent implantation were associated with calcified neoatherosclerosis. Multivariable Cox regression revealed that female sex and lipidic neoatherosclerosis were associated with more target lesion failure, whereas stent age and final minimum lumen diameter after reintervention were related to lower target lesion failure. Calcified neoatherosclerosis was not related to adverse events after reintervention for in-stent restenosis given a large enough minimum lumen diameter was achieved.

CONCLUSIONS

Lipidic but not calcified neoatherosclerosis was associated with poor subsequent outcomes after repeat revascularization if optimal stent expansion was achieved in lesions with calcified neoatherosclerosis.

Manual Thrombus Aspiration and its Procedural Stroke Risk in Myocardial Infarction

Background

The previous large‐scale randomized controlled trial showed that routine thrombus aspiration (TA) during percutaneous coronary intervention (PCI) was associated with an increased risk of stroke. However, real‐world clinical evidence is still limited.

Methods and Results

We investigated the association between manual TA and stroke risk during primary PCI in the OACIS (Osaka Acute Coronary Insufficiency Study) database (N=12 093). The OACIS is a prospective, multicenter registry of myocardial infarction. The primary end point of the present study is stroke at 7 days. A total of 9147 patients who underwent primary PCI within 24 hours of hospitalization were finally analyzed (TA group, n=4448, versus non‐TA group, n=4699 patients). TA was independently associated with risk of stroke at 7 days (odds ratio [OR], 1.92 [95% CI, 1.19‒3.12]; P=0.008) in the simple logistic regression model, while the multilevel random effects logistic regression model with hospital treated as a random effect showed that manual TA was not associated with incremental risk of stroke at 7 days (OR, 0.91 [95% CI, 0.71‒1.16]; P=0.435). The 7‐day stroke risk of manual TA was significantly heterogeneous in different institutions (P_{for interaction}=0.007).

Conclusions

Manual TA during primary PCI for patients with acute myocardial infarction was independently associated with the overall increased risk of periprocedural stroke. However, this result was substantially skewed because of institution specific risk variation, suggesting that the periprocedural stroke may be preventable by prudent PCI procedure or appropriate periprocedural management.

Registration

URL: https://upload.umin.ac.jp/cgi‐open‐bin/ctr_e/ctr_view.cgi?recptno=R000005464. Unique identifier: UMIN000004575.

Practical Assessment of the Tradeoff between Fatal Bleeding and Coronary Thrombotic Risks using the Academic Research Consortium for High Bleeding Risk Criteria

Aims: We aimed to establish a practical method for the assessment of tradeoff between thrombotic and bleeding risks.

Methods: We aimed to investigate the balance between bleeding risk and coronary thrombotic risk according to the number of the Academic Research Consortium for high bleeding risk (ARC-HBR) criteria in the multicenter prospective ST/non-ST elevation myocardial infarction (STEMI/NSTEMI) registry (N=12,093). Patients were divided as follows by the number of ARC-HBR criteria fulfilled: group 0, 0 major with ≤ 1 minor (N=6,792); group 1, 1 major with 0 minor (N=1,705); group 2, 0 major with ≥ 2 minors (N=790); group 3, 1 major with ≥ 1 minor (N=1,709); group 4, 2 majors with ≥ 0 minors (N=861); and group 5, ≥ 3 majors with ≥ 0 minor (N=236). We assessed the acute-phase absolute risk differences between bleeding and coronary thrombotic events in each group.

Results: At 7-day follow-up, all patients (groups 0–5) had a higher risk of major bleeding than that of any myocardial infarction (MI). Patients at ARC-HBR (groups 1–5) had a balanced risk between fatal MI and fatal bleeding, whereas patients at non-ARC-HBR (group 0) had a higher risk of fatal MI than that of fatal bleeding.

Conclusions: All STEMI/NSTEMI patients have a relatively high risk of major bleeding as compared with the risk of any MI in the acute phase. The ARC-HBR criteria would be a practical tool for assessing the tradeoff between fatal bleeding and fatal MI risks. This practical assessment would be helpful for the optimal decision-making of appropriate treatment strategy considering the balance between bleeding and coronary thrombotic risks.

Clinical outcomes for intracoronary imaging strategies at different medical facilities in Japanese patients with coronary artery disease: the SAKURA imaging PCI Registry

The relationships between intracoronary imaging modalities and outcomes among Japanese patients with coronary artery disease (CAD) based on the type of medical facility providing outpatient care remain unclear. In this multicenter prospective study (SAKURA PCI Registry), we aimed to investigate the clinical outcomes of patients with CAD who underwent percutaneous coronary intervention (PCI) between April 2015 and December 2018. In this registry, we investigated differences in patient characteristics, intracoronary imaging modalities, and clinical outcomes between two types of medical facilities. Of the 414 patients enrolled in this registry, 196 were treated at two university hospitals, and 218 were treated at five community hospitals (median follow-up 11.0 months). The primary endpoint was clinically relevant events (CREs), including a composite of all-cause death, non-fatal myocardial infarction, clinically driven target lesion revascularization, stent thrombosis, stroke, and major bleeding. Patients treated at university hospitals had higher rates of diabetes (50% vs. 38%, p = 0.015) and malignant tumors (12% vs. 6%, p = 0.015) and more frequent use of multiple intracoronary imaging modalities than patients treated at community hospitals (21% vs. 0.5%, p < 0.001). The Kaplan-Meier incidence of CREs at 1 year was comparable between university hospitals and community hospitals (8.8% vs. 7.3%, p = 0.527, log-rank test). Despite the relatively higher risk among patients in university hospitals with frequent use of multi-intracoronary imaging modalities, adverse clinical events appeared to be comparable between patients with CAD treated at university and community hospitals in Japan.

Consensus document on the standard of coronary angioscopy examination and assessment from the Japanese Association of Cardiovascular Intervention and Therapeutics

Coronary angioscopy (CAS) is a unique diagnostic device that allows direct visualization of the vascular luminal surface in living patients. CAS contributes to elucidate the pathology of coronary artery disease. This consensus document provides a standard for CAS examination and assessment.

Quantitative Validation of the Coronary Angioscopic Yellow Plaque with Lipid Core Burden Index Assessed by Intracoronary Near-Infrared Spectroscopy

Aim: We aimed to validate the subjective and qualitative angioscopic findings by the objective and quantitative near-infrared spectroscopic (NIRS) assessment to compensate each other’s drawbacks.

Methods: This is a single-center prospective observational study. Patients undergoing a planned follow-up coronary angiography after percutaneous coronary intervention were prospectively enrolled from January 2018 to April 2019. The major three vessels were examined by NIRS-intravascular ultrasound, followed by coronary angioscopic evaluation. Yellow color grade on angioscopy was classified into four grades (0, white; 1, slight yellow; 2, yellow; and 3, intensive yellow) at a location of maximal lipid core burden index over 4 mm [LCBI (4)] on NIRS in each vessel.

Results: A total of 95 lesions in 44 patients (72.6±6.7 years, 75% male) were analyzed. LCBI (4) was significantly different among different yellow color grades by coronary angioscopy (ANOVA, p ＜0.001). Positive correlation was found between angioscopic yellow color grade and LCBI (4) (beta coefficient 164.8, 95% confidence interval 122.9–206.7; p ＜0.001). The best cutoff value of LCBI (4) to predict the presence of yellow plaque (yellow color grade ≥ 2) was 448 (sensitivity 79.3%, specificity 69.7%, C-statistic 0.800, 95% confidence interval 0.713–0.887, p ＜0.001).

Conclusion: The qualitative angioscopic assessment was objectively validated by the quantitative NIRS evaluation, which would be helpful for the reinterpretation of the existing evidences of both imaging modalities.

Impact of diabetes mellitus on the early-phase arterial healing after drug-eluting stent implantation

BACKGROUND

Early arterial healing after drug-eluting stent (DES) implantation may enable short dual-antiplatelet therapy (DAPT) strategy. The impact of diabetes mellitus (DM) on this healing has not been elucidated. We used coronary angioscopy (CAS) to compare intravascular status of DM and non-DM patients in the early phase after DES implantation.

METHODS

This study was a multicenter retrospective observational study. We analyzed CAS findings of 337 lesions from 270 patients evaluated 3-5 months after DES implantation. We divided the lesion into two groups: DM (n = 149) and non-DM (n = 188). We assessed neointimal coverage (NIC) grades (dominant, maximum and minimum), thrombus adhesion and maximum yellow color grade. NIC was graded as follows: grade 0, stent struts were not covered; grade 1, stent struts were covered by thin layer; grade 2, stent struts were buried under neointima. Yellow color was graded as grade 0, white; grade 1, light yellow; grade 2, yellow; grade 3, intensive yellow.

RESULTS

Minimum NIC grade was significantly lower in DM than in non-DM groups (p = 0.002), whereas dominant and maximum NIC grades were similar between them (p = 0.59 and p = 0.94, respectively), as were thrombus adhesion (44.3% vs. 38.8%, p = 0.32) and maximum yellow color grade (p = 0.78). A multivariate analysis demonstrated that DM was an independent predictor of minimum NIC of grade 0 (odds ratio: 2.14, 95% confidence interval: 1.19-3.86, p = 0.011).

CONCLUSIONS

DM patients showed more uncovered struts than non-DM patients 3-5 months after DES implantation, suggesting that the recent ultra-short DAPT strategy might not be easily applied to DM patients.

Impact of different coronary angioscopic findings on arterial healing one year after bioresorbable-polymer and second-generation durable-polymer drug-eluting stent implantation

BACKGROUND

The advantage of using bioresorbable-polymer drug-eluting stent (BP-DES) compared with second-generation durable-polymer drug-eluting stent (2G DP-DES) still remains controversial in clinical situations. The purpose of this study to evaluate the degree of re-endothelialization and the prevalence of high-grade yellow-colored plaque (YCP), which might concern arterial healing after BP-DES and 2G DP-DES implantation using a high-resolution coronary angioscopy (CAS).

METHODS

In total, 104 DESs (52: 2G DP-DES and 52: BP-DES) were prospectively observed using CAS 12±1 months after coronary intervention. The grade of neointimal coverage (NIC) over the stent was scored on a 4-point scale from 0 (no coverage) to 3 (complete coverage). YCP grade was also scored on a 4-point scale as 0 (white) to 3 (intensive yellow). High-grade YCP was defined as maximum grade ≥2. Moreover, the prevalence of high-grade YCP and the incidence of thrombus were investigated.

RESULTS

BP-DES revealed better dominant NIC grade and less NIC heterogeneity than 2G DP-DES (p=0.0001 and p=0.015, respectively). The prevalence of high-grade YCP was lower for BP-DES than for 2G DP-DES (p=0.05). However, the incidence of thrombus was not significantly different (p=0.41). Multivariate analysis identified that low-density lipoprotein cholesterol levels [odds ratio (OR), 1.03; 95% Confidence Interval (CI): 1.01-1.06, p=0.01] and the usage of BP-DES [OR, 0.36; 95% CI: 0.14-0.91, p=0.03] as independent predictors of high-grade YCP.

CONCLUSIONS

Compared with 2G DP-DES, BP-DES was less heterogeneous and well-covered NIC and less prevalence of the high-grade YCP implying optimal arterial healing.

Serial optical coherence tomography and angioscopic assessments of 10-year in-stent restenosis of Cypher sirolimus-eluting stent treated with drug-coated balloon angioplasty

The drug-coated balloon (DCB) angioplasty is considered a standard therapeutic option for in-stent restenosis. In the present case, we observed high-intensity spots on optical coherence tomography (OCT) and bright spots on coronary angioplasty (CAS) immediately after DCB angioplasty. The superficial high-intensity area on OCT presumably corresponded with the bright spots on CAS. The high-intensity superficial regions were thought to represent an iopromide/paclitaxel mixture. The present serial observation demonstrated that the eluted drugs remained for at least 2 months but disappeared within 6 months. At the site where we observed the drugs, neointimal growth was successfully inhibited and stabilized at the 6-month follow-up. The association of eluted drugs after DCB angioplasty with consequent neointimal growth is of scientific interest. Further prospective imaging studies with a large sample size are warranted to clarify this association.