Assessment of vascular response after drug-eluting stents implantation in patients with diabetes mellitus: an optical coherence tomography sub-study of the J-DESsERT

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.

Microbubble contrast enhancement of neointima after drug-eluting stent implantation: an optical coherence tomography study

Microvessels within neoatherosclerosis are associated with vulnerability and increase from the early to the very late phase after drug-eluting stent implantation. Microbubble contrast agents have been suggested to enhance tissue microvasculature for optical coherence tomography (OCT) imaging. The present study investigated whether OCT signal intensity of neointima within stented segments was enhanced after intracoronary administration of microbubble contrast agents. A total of 40 patients who underwent follow-up coronary angiography after drug-eluting stent implantation were enrolled. At the time of follow-up coronary angiography, OCT images of the stented segments were recorded before and after intracoronary administration of microbubble contrast agents. Mean OCT signal intensity of neointima after microbubble administration significantly increased [95.5 (85.7, 106.2) vs. 96.5 (88.7, 109.9), p = 0.001]. Multivariate analysis demonstrated the relationship between diabetes and greater neointima enhancement. The change in the OCT signal intensity of neointima following microbubble administration tended to be higher in diabetic patients than in non-diabetic patients [4.6 (0.6, 8.5) vs. 1.4 (- 1.1, 3.0), p = 0.05]. These findings suggest that this methodology may allow identification of neovascularization in neointima and evaluation of vulnerability of neoatherosclerosis. Microvessels in neointima may be a future target of pharmacological and interventional innovations for preventing stent failure.

Incidence and Predictors of the In-stent Restenosis after Vertebral Artery Ostium Stenting

BACKGROUND

The incidence and predictors for in-stent restenosis (ISR) was not fully explored. We aim to investigate the incidence and predictors of ISR after stenting at the origin of vertebral artery.

MATERIALS AND METHODS

Two hundred and six patients with 229 stents implantation between July 1, 2005 and July 31, 2015 were included in the study. All patients underwent conventional clinical and angiographic (digital subtraction angiography) follow-up at around 6 months post procedure. ISR was defined as greater than 50% stenosis within or immediately (within 5 mm) adjacent to the stent. Multivariate Cox regression analyses were utilized to investigate the predictors for ISR.

RESULTS

The ISR was found in 30 patients (30/206, 14.6%) with 31 lesions (31/229, 13.5%) with the mean follow-up duration of 11.1-month (range: 3 - 92 months). Stent diameter (hazard ratio 0.504, 95% confidence interval 0.294 - 0.864) was an independent predictor for ISR.

CONCLUSION

ISR rate after Vertebral artery ostium stent placement is acceptable, which was conversely associated with the stent diameter.

Randomised trial of the comparison of drug-eluting stents in patients with diabetes: OCT DES trial

Background

To date, there have been limited comparisons performed between everolimus-eluting stents (EES) and zotarolimus-eluting stents (ZES) in patients with diabetes mellitus (DM). The objectives of this study was to assess the use of second-generation drug-eluting stents in patients with DM, using optical coherence tomography (OCT) to compare the level of stent coverage of Boston Scientific Promus Element EES compared with Medtronic Resolute Integrity ZES.(Clinicaltrials.gov number NCT02060357).

Methods

This is a single-centre randomised blinded trials assessing two commercially available stents in 60 patients with diabetes (ZES: n=30, EES: n=30). Patients underwent intracoronary assessment at 6 months with OCT assessing stent coverage, malapposition, neointimal thickness and percentage of in-stent restenosis (ISR).

Results

Of the 60 patients randomised, 46 patients underwent OCT analysis. There was no difference in baseline characteristics between the two groups. Both Promus Element and Resolute Integrity had low rates of uncovered struts at 6 months with no significant difference between the two groups (2.44% vs 1.24%, respectively; P=0.17). Rates of malapposition struts (3.9% vs 2.5%, P=0.25) and percentage of luminal loss did not differ between stent types. In addition, there was no significant difference in major adverse cardiovascular events (P=0.24) between the stent types.

Conclusions

This study is the first randomised trial to evaluate OCT at 6 months for ZES and EES in patients with diabetes. Both stents showed comparable strut coverage at 6 months, with no difference in ISR rates at 6 months.

Effectiveness and Safety of Biolimus A9™-Eluting stEnt in Patients with AcUTe Coronary sYndrome; A Multicenter, Observational Study (BEAUTY Study)

PURPOSE

This study sought to determine the 1-year clinical effectiveness and safety of a biodegradable, polymer-containing Biolimus A9™-eluting stent (BES) in Korean patients with acute coronary syndrome (ACS).

MATERIALS AND METHODS

A total of 1000 ACS patients with 1251 lesions who underwent implantation of BESs at 22 centers in Korea were enrolled between May 2011 and July 2013. We assessed major adverse cardiac events (MACE) defined as the composite of cardiac death, non-fatal myocardial infarction (MI), and clinical-driven target vessel revascularization at 12 months.

RESULTS

Patient mean age was 62.6±11.4 years. 72.8% of the patients were male, 28.5% had diabetes, 32.8% had multi-vessel disease (MVD), and 47.9% presented with acute MI (AMI). The mean global registry of acute coronary events risk score of all patients was 103.0±27.6. The number of stents per patient was 1.3±0.6. The incidences of MACE and definite stent thrombosis at 12 months were 3.9% and 0.2%, respectively. On multivariate Cox-regression analysis, age ≥65 years was identified as an independent predictors of 1-year MACE (hazard ratio=2.474; 95% confidence interval=1.202-5.091). Subgroup analyses revealed no significant differences in the incidence of MACE between patients with and without diabetes (4.3% vs. 3.7%, p=0.667), between those who presented with and without AMI (4.4% vs. 3.4%, p=0.403), and between those with and without MVD (4.6% vs. 3.5%, p=0.387).

CONCLUSION

Our study demonstrated excellent 1-year clinical outcomes of BES implantation in patients at low-risk for ACS.

Two-year vascular responses to drug-eluting stents with biodegradable polymer versus durable polymer: An optical coherence tomography sub-study of the NEXT

BACKGROUND

This study aimed to compare very late vascular response after stent implantation between everolimus-eluting stent (EES) with a thin, non-adhesive, durable, biocompatible fluorinated polymer and biolimus-eluting stent (BES) with a biodegradable polymer by optical coherence tomography (OCT).

METHODS AND RESULTS

In the NOBORI-BES Versus XIENCE V/PROMUS-EES Trial (NEXT), a formal OCT substudy investigated 48 patients (27 EES-treated lesions in 23 patients and 28 BES-treated lesions in 25 patients) with 2-year (18-30 months) follow-up imaging at 18 centers. The percentage of uncovered strut by neointima was significantly lower in EES compared with BES (2.1±4.7% vs. 7.9±10.8%, p=0.013). The percentage of malapposed strut was not different between EES and BES (0.1±0.3% vs. 0.5±1.3%, p=0.138). The frequency of stent with evagination, which is identified as outward bulges in the luminal contour between struts, was significantly lower in EES compared with BES (22% vs. 86%, p<0.001). The frequency of neoatherosclerosis was not different between EES and BES (11% vs. 11%, p=1.000).

CONCLUSIONS

At 2 years after stent implantation, uncovered stent strut by neointima and evagination were less frequently observed in EES compared with BES. This OCT study suggests that the very late vascular response is different between EES and BES.

Impact of catheter size on reliability of quantitative coronary angiographic measurements (comparison of 4Fr and 6Fr catheters)

To evaluate the feasibility of catheter down sizing for QCA, the reliability of a 4Fr catheter as a calibration device was evaluated. Repeated coronary angiograms of 9 lesions were obtained using 4Fr and 6Fr catheters under otherwise identical conditions. The calibration factor was measured 10 times by 4Fr and 6Fr catheters. QCA measurements including minimal lumen diameter (MLD), interpolated normal reference (Int N), percent diameter stenosis (%DS), and lesion length (LL) were performed by two technicians twice with a 3-month interval. The intraobserver and interobserver variability of each parameter was evaluated using intraclass correlation coefficients (ICCs). Mean of mean SD of calibration factor was significantly larger in 4Fr than in 6Fr in 9 lesions. The mean of mean coefficient of variance was significantly larger in 4Fr catheters vs in 6Fr catheters. A 6Fr catheter showed excellent reliability for both intraobserver and interobserver variability in MLD, Int N, %DS, and LL. In contrast, 4Fr showed that reliability in intraobserver variability depended on the analyst. Although reliability of interobserver variability in Int N measured by the 4Fr catheter was >0.80, the value was less than that by the 6Fr catheter. Taking these results into consideration, 4Fr catheters are less reliable than 6Fr catheters when measuring QCA data especially for follow-up data that need most accurate measurements of MLD and %DS. It would be better to use a 6Fr catheter to evaluate QCA measurements such as acute gain, late loss, restenosis rate, and device size.