Serial Optical Coherence Tomography Evaluation at 6, 12, and 24 Months After Biolimus A9-Eluting Biodegradable Polymer-Coated Stent Implantation

Comparative study of neointimal coverage between titanium-nitric oxide-coated and everolimus-eluting stents in acute coronary syndromes

INTRODUCTION AND OBJECTIVES

To evaluate by optical coherence tomography neointimal healing response after implantation of cobalt-chromium-based titanium-nitride-oxide-coated (TiNO) stents and platinum-chromium-based biodegradable-polymer-coated everolimus-eluting stents (EES) in patients with acute coronary syndrome.

METHODS

Patients were randomized (1:1) to receive either a TiNO-stent or EES. Optical coherence tomography images were obtained at 30-day (cohort A, n = 52) and 6-month (cohort B, n = 30) follow-up. The primary endpoint was the percentage of uncovered struts per patient.

RESULTS

In cohort A, the percentage of uncovered struts was lower with TiNO-stents vs EES (3.2% vs 19.6%, P <.001). The percentage of malapposed struts was 0.4% in the TiNO-group and 2.1% in the EES group (P <.001). In cohort B, the percentage of uncovered struts was also lower with TiNO-stents (0.0% vs 8.7%, (P <.001). The percentage of malapposed struts was 0% in the TiNO-stent group and 0.3% in the EES group, (P=.008). None of the patients had repeat revascularization during the 6 months of follow-up.

CONCLUSIONS

Following percutaneous intervention for acute coronary syndrome, TiNO stent implantation was associated with a lower percentage of uncovered and malapposed struts per patient, compared with EES, at early and mid-term follow-up. This study is registered under ClinicalTrials.gov, with number NCT02464397.

Impact of the Antithrombotic Effects of Prasugrel on Mid-Term Vascular Healing in Acute Coronary Syndrome vs. Stable Coronary Artery Disease

BACKGROUND

The impact of antiplatelet drug effects on mid-term local arterial responses following percutaneous coronary intervention (PCI) remains uncertain. We evaluated the impact of the platelet reactivity of prasugrel on mid-term vascular healing between acute coronary syndrome (ACS) and stable coronary artery disease (CAD).

METHODS AND RESULTS

We conducted a prospective, 12-center study in 125 patients with ACS and 126 patients with stable CAD who underwent PCI with an everolimus-eluting stent (EES) and received dual antiplatelet therapy (DAPT) with prasugrel and aspirin. Serial optical coherence tomography (OCT) was performed immediately after PCI and at the 9-month follow-up to assess the association of P2Y12reaction units (PRU) with the frequency of malapposed or uncovered struts and intrastent thrombi (IST). The incidence of abnormal mid-term OCT findings did not different between the ACS and CAD arms, regardless of clinical presentation, except that uncovered struts were more frequent in the ACS than CAD arm. PRU at PCI was significantly associated with the frequency of IST at follow-up, but not with uncovered and malapposed struts. PRU at PCI was the only independent predictor of IST detected at follow-up (odds ratio 1.009).

CONCLUSIONS

In patients undergoing EES implantation and receiving prasugrel, achieving an adequate antiplatelet effect at the time of stent implantation may regulate thrombus formation throughout the follow-up period.

Early Vascular Healing Following Bioresorbable-Polymer Sirolimus-Eluting Stent Placement Compared to That with Durable-Polymer Everolimus-Eluting Stent

A recent thinner strut drug-eluting stent might facilitate early strut coverage after its placement. We aimed to investigate early vascular healing responses after the placement of an ultrathin-strut bioresorbable-polymer sirolimus-eluting stent (BP-SES) compared to those with a durable-polymer everolimus-eluting stent (DP-EES) using optical coherence tomography (OCT) imaging.This study included 40 patients with chronic coronary syndrome (CCS) who underwent OCT-guided percutaneous coronary intervention (PCI). Twenty patients each received either BP-SES or DP-EES implantation. OCT was performed immediately after stent placement (baseline) and at 1-month follow-up.At one month, the percentage of uncovered struts reduced significantly in both the BP-SES (80.9 ± 10.3% to 2.9 ± 1.7%; P < 0.001) and DP-EES (81.9 ± 13.0% to 5.7 ± 1.8%; P < 0.001) groups, and the percentage was lower in the BP-SES group than in the DP-EES group (P < 0.001). In the BP-SES group, the percentage of malapposed struts also decreased significantly at 1 month (4.9 ± 3.7% to 2.6 ± 3.0%; P = 0.025), which was comparable to that of the DP-EES group (2.5 ± 2.2%; P = 0.860). The optimal cut-off value of the distance between the strut and vessel surface immediately after the placement to predict resolved malapposed struts was ≤ 160 μm for BP-SES and ≤ 190 μm for DP-EES.Compared to DP-EES, ultrathin-strut BP-SES demonstrated favorable vascular responses at one month, with a lower rate of uncovered struts and a comparable rate of malapposed struts.

Favorable early vessel healing after everolimus-eluting stent implantation: 3-, 6-, and 12-month follow-up of optical coherence tomography

BACKGROUND

Although a prospective randomized control study revealed that 3-month dual anti-platelet therapy (DAPT) is safe and does not compromise the efficacy of everolimus-eluting stent (EES) in selected patients, detailed vessel healing at early phase after EES implantation has yet to be investigated in Japanese patients.

METHODS AND RESULTS

A total of 27 lesions in 19 patients treated with EES were serially evaluated by using optical coherence tomography (OCT) at 3, 6, and 12 months after stent implantation. In addition to standard quantitative OCT parameters, the percentage of stents with peri-strut low-intensity area (PLIA, a region around stent struts homogenously showing lesser intensity than the surrounding tissue, suggesting fibrin deposition or impaired neointima maturation) and that with in-stent thrombi were evaluated. There was a significant, but small increase in neointimal thickness (63±17μm; 83±30μm; and 111±44μm, respectively; p=0.006) and small decrease in average lumen area (6.80±2.57mm², 6.62±2.58mm², 6.33±2.58mm², p=0.038) from the 3- to the 12-month follow-up. The incidences of uncovered and malapposed struts were low at 3 months and did not significantly change at 6 months and 12 months (3.01±4.43; 2.45±3.75; and 1.47±3.16, p=0.143, and 0.75±0.65; 0.63±0.73; and 0.58±1.42, p=0.162, respectively). Also, frequency of struts with PLIA was already low at three months and significantly decreased during the follow-up (6.4±6.5; 4.6±5.4; and 2.3±3.3, respectively; p=0.001).

CONCLUSION

Favorable vessel healing was achieved at 3 months after EES implantation without neointimal hyperplasia which was persistently suppressed up to 12 months.

Vascular response to biolimus A-9 eluting stent in patients with shorter and prolonged dual antiplatelet therapy: optical coherence tomography sub-study of the NIPPON trial

Dual antiplatelet therapy (DAPT) with thienopyridine and aspirin is the standard care for the prevention of stent thrombosis. However, the optimal duration and effect of the duration of DAPT on intra-stent thrombus (IS-Th) formation are unknown. The NIPPON study (Nobori Dual Antiplatelet Therapy as Appropriate Duration) was an open label, randomized multicenter, assessor-blinded, trial designed to demonstrate the non-inferiority of shorter (6-month) DAPT to prolonged (18-month) DAPT, after biolimus A9 eluting stent implantation in 3773 patients at 130 sites in Japan. Among them, 101 patients were randomly allocated for an optical coherence tomography (OCT) sub-study to assess the difference of local IS-Th formation between the two groups. In addition to standard OCT parameters, the number of IS-Th formed was counted in each target stent at 8 months. Baseline patient characteristics were not different between the 6- and 18-month groups. IS-Th was detected in 9.8% of the cases and the presence of IS-Th was not significantly different between the two groups (10.9% in 6-month vs. 9.1% in 12-month, P = 0.76). Furthermore, the number of IS-Th formed was not significantly different between the two groups. This OCT sub-study was in line with the main NIPPON study which demonstrated the non-inferiority of 6-month DAPT to 18-month DAPT. Shorter DAPT duration did not promote progressive IS-Th formation at the mid-term time point.

Optical coherence tomography follow-up 18 months after titanium-nitride-oxide-coated versus everolimus-eluting stent implantation in patients with acute coronary syndrome

Background Inadequate neointimal coverage of stent struts is associated with late stent thrombosis. Purpose To demonstrate the extent of neointimal coverage and strut malapposition in titanium-nitride-oxide-coated bioactive stents (BAS) versus everolimus-eluting stents (EES) by optical coherence tomography (OCT) performed at 18-month follow-up. Material and Methods In the BASE-ACS trial, 827 patients presenting with acute coronary syndrome were randomized to receive either BAS or EES. Forty patients (20 BAS, 20 EES) underwent OCT at 18-month follow-up for evaluation of stent strut coverage, malapposition, and neointimal hyperplasia (NIH). Primary endpoint was binary stent strut coverage (ratio of covered struts to all analyzed struts multiplied by 100). Co-primary endpoint was the percentage of malapposed struts. Results We analyzed 3465 struts in 330 cross-sections of BAS and 3327 struts in 316 cross-sections of EES. Binary stent strut coverage, based on strut-level analysis, was higher with BAS versus EES (99.5% versus 94.2%, respectively; P < 0.001), the strut-level percentage of malapposed struts was lower with BAS (0.6% versus 2.5%, respectively; P < 0.001). Yet, the mean NIH thickness was greater with BAS (237 ± 125 versus 108 ± 62 µm, respectively; P < 0.001). Conclusion In the current post-hoc analysis with OCT performed at 18 months, binary strut coverage, based on strut-level analysis, was higher with BAS versus EES; strut-level malapposed struts were fewer with BAS; yet, BAS induced thicker NIH.

Third generation drug eluting stent (DES) with biodegradable polymer in diabetic patients: 5 years follow-up

Objective

To report the long-term safety and efficacy data of a third generation drug eluting stent (DES) with biodegradable polymer in the complex patient population of diabetes mellitus after a follow-up period of 5 years.

Background

After percutaneous coronary intervention patients with diabetes mellitus are under higher risk of death, restenosis and stent thrombosis (ST) compared to non-diabetic patients.

Methods

In 126 centers worldwide 3067 patients were enrolled in the NOBORI 2 registry, 888 patients suffered from diabetes mellitus (DM), 213 of them (14%) being insulin dependent (IDDM). Five years follow-up has been completed in this study.

Results

At 5 years, 89.3% of the patients were available for follow-up. The reported target lesion failure (TLF) rates at 5 years were 12.39% in DM group and 7.34% in non-DM group; (p < 0.0001). In the DM group, the TLF rate in patients with IDDM was significantly higher than in the non-IDDM subgroup (17.84 vs. 10.67%; p < 0.01). The rate of ST at 5 years was not different among diabetic versus non-diabetic patients or IDDM versus NIDDM. Only 10 (<0.4%) very late stent thrombotic events beyond 12 months occurred.

Conclusions

The Nobori DES performed well in patients with DM. As expected patients with DM, particularly those with IDDM, had worse outcomes. However, the very low rate of very late stent thrombosis in IDDM patients might have significant clinical value in the treatment of these patients.

Clinical trial registration ISRCTN81649913; http://www.controlled-trials.com/isrctn/search.html?srch=81649913&sort=3&dir=desc&max=10

Intracoronary Imaging in the Detection of Vulnerable Plaques

Coronary artery disease is the result of atherosclerotic changes to the coronary arterial wall, comprising endothelial dysfunction, vascular inflammation and deposition of lipid-rich macrophage foam cells. Certain high-risk atherosclerotic plaques are vulnerable to disruption, leading to rupture, thrombosis and the clinical sequelae of acute coronary syndrome. Though recognised as the gold standard for evaluating the presence, distribution and severity of atherosclerotic lesions, invasive coronary angiography is incapable of identifying non-stenotic, vulnerable plaques that are responsible for adverse cardiovascular events. The recognition of such limitations has impelled the development of intracoronary imaging technologies, including intravascular ultrasound, optical coherence tomography and near-infrared spectroscopy, which enable the detailed evaluation of the coronary wall and atherosclerotic plaques in clinical practice. This review discusses the present status of invasive imaging technologies; summarises up-to-date, evidence-based clinical guidelines; and addresses questions that remain unanswered with regard to the future of intracoronary plaque imaging.