Short- and mid-term influence of drug-coated stent implantation on structural and functional vascular healing response: An optical coherence tomography and acetylcholine testing study.

OBJECTIVE: This study investigated the effect of a drug-coated stent (DCS) that has a novel microporous abluminal surface without a polymer on 1-month and 1-year functional and morphological healing response as assessed using acetylcholine (Ach) testing and optical coherence tomography (OCT). BACKGROUND: DCS is expected to induce favorable morphological and physiological arterial healing after its implantation. METHODS: A total of 11 patients who underwent vascular response examinations 1-month and 1-year after the index PCI with DCS implantation were enrolled. The vascular response was evaluated by the functional response test by acetylcholine infusion, the morphological response test by OCT. RESULTS: Although 94.5% of the DCS struts were covered by homogeneous smooth neointima at 1 month, the percentage of neointimal coverage increased to 98.5% at 1 year (p = .02). Conversely, the proportion of uncovered struts and malapposed struts at 1 year were 1.2 and 0.7%, respectively. Furthermore, the coronary vasomotor response to incremental doses of Ach were impaired especially in the distal segments at each period, although the responses to Ach at 10-6 mol/L in the distal segment tended to improve over time from baseline to 1 month and 1 year later (-19 ± 20%, -9 ± 17%, and -5 ± 14%, respectively; p = .27). CONCLUSIONS: The morphological assessment of DCS with OCT revealed a high degree of strut coverage and apposition at 4 weeks after implantation. The impaired endothelium-dependent vasomotor response tended to improve chronologically from baseline to 1 month and 1 year later.

Impact of optical coherence tomography-derived neointimal tissue morphology on development of very late in-stent restenosis.

OBJECTIVES: This study evaluated the progression of very late in-stent restenosis (VL-ISR) by analyzing four serial coronary angiography (CAG) images and its correlation with neointimal tissue characterization of the VL-ISR lesions on optical coherence tomography (OCT). BACKGROUND: Recently, VL-ISR is occasionally observed beyond a few years after drug-eluting stents (DESs) implantation. METHODS: This study analyzed 50 VL-ISR lesions after DES in which 4 serial CAGs over a period of 2 years, including at baseline procedure, 9 months after baseline procedure, 12 months before VL-ISR, and at the time of VL-ISR, were performed. Neointimal tissue characteristics by OCT were categorized as homogeneous, heterogeneous with invisible strut (Type I), heterogeneous with visible strut (Type II), speckled (Type III), or heterogeneous with sharply delineated border (Type IV). RESULTS: From the development process, 23 VL-ISRs (46%) were categorized as rapid progression and 27 (54%) as gradual progression. The five categories of neointimal tissue composition significantly differed between lesions with rapid and gradual progression. Homogeneous neointima and Type IV heterogeneous neointima were observed only in lesions with gradual progression. Moreover, most Type I heterogeneous neointima was identified in lesions with gradual progression. Instead, main neointimal tissue components of lesions with rapid progression were Type II (43%) and Type III (43%) heterogeneous neointima. CONCLUSION: The progression rate of in-stent atherosclerotic changes is gradual, whereas organized thrombus could be associated with an increased risk of rapid neointimal growth. The two types of stenosis progression provide a new insight into the mechanism of VL-ISR development after DES implantation.

Effect of neointimal tissue morphology on vascular response to balloon angioplasty in lesions with in-stent restenosis after drug-eluting stent deployment: an optical coherence tomography analysis.

This study aimed to evaluate the vascular response to balloon angioplasty for drug-eluting stent (DES) in-stent restenosis (ISR) lesions based on our novel optical coherence tomography (OCT) classification to establish the optimal treatment strategy for ISR lesions after DES implantation. A total of 104 ISR lesions after DES implantation were imaged by OCT and categorized into the following six patterns: type I-homogeneous high-intensity tissue, type II-heterogeneous tissue with signal attenuation, type III-speckled heterogeneous tissue, type IV-mixed tissue containing poorly delineated region with invisible strut, type V-mixed tissue containing sharply delineated low-intensity region, and type VI-bright protruding tissue with an irregular surface. Serial volumetric OCT analysis was performed before and after balloon dilation to evaluate the vascular response to balloon angioplasty. After balloon dilation, the minimal decrease in neointimal volume was noted in type I lesions and maximal in type III lesions. In contrast, the increase in stent volume was significantly more in type I lesions than others. Neointimal tissue characterization by OCT allows us to provide useful information about the vascular response to balloon dilation, which can influence the therapeutic strategy for DES ISR lesions.

Optical coherence tomography characteristics of in-stent restenosis after drug-eluting stent implantation: a novel classification and its clinical significance.

This study aimed to establish a novel classification of in-stent restenosis (ISR) morphological characteristics after drug-eluting stent (DES) implantation as visualized by optical coherence tomography (OCT) and determine its clinical significance. A total of 133 lesions with intrastent restenosis after DES implantation were imaged by OCT. Neointimal tissue characteristics were categorized according to the classical classification as either homogeneous, heterogeneous, or layered. Then all tissues were also classified into six types as follows: homogeneous high-intensity tissue (type I), heterogeneous tissue with signal attenuation (type II), speckled heterogeneous tissue (type III), heterogeneous tissue containing poorly delineated region with invisible strut (type IV), heterogeneous tissue containing sharply delineated low-intensity region (type V), or bright protruding tissue with an irregular surface (type VI). The kappa value for interobserver agreement between the two observers was higher in the modified classification than in the classical classification (0.97 and 0.72, respectively). Most lesions classified as type V and VI were likely to be identified in patients on hemodialysis and located at the ostial right coronary artery. The duration from stent implantation to ISR was significantly longer in types IV and VI than in others. The incidence of stent fracture was significantly higher in types I and IV. This new modified classification enabled us to classify most ISR lesions easily with higher reproducibility. The clinical significance of neointimal restenotic tissue classification by OCT became clear while using the modified classification.

Utility and Validity of Intracoronary Administration of Nicorandil Alone for the Measurement of Fractional Flow Reserve in Patients With Intermediate Coronary Stenosis.

BACKGROUND: Intracoronary (IC) administration of nicorandil has been proposed as an alternative choice of hyperemic agent for fractional flow reserve (FFR) measurements. This study evaluated the utility and validity of IC nicorandil administration alone to induce maximal hyperemia.Methods and Results:Two-hundred-seven patients with coronary artery disease listed for coronary angiography with FFR were prospectively enrolled. FFR was measured after (1) IC administration of nicorandil 2 mg (ICNIC2 mg); (2) continuous intravenous (IV) adenosine triphosphatase (ATP) infusion at 150 µg/kg/min (IVATP150); (3) IV ATP infusion at 210 µg/kg/min (IVATP210); (4) IC administration of 0.5 mg nicorandil during IVATP150 (ICNIC0.5 mg+IVATP150); (5) IC administration of 1 mg nicorandil during IVATP150 (ICNIC1 mg+IVATP150); and (6) IC administration of 2 mg nicorandil during IVATP150 (ICNIC2 mg+IVATP150). The average FFR values and the rate of achieving maximum hyperemia after ICNIC2 mg, IVATP150, IVATP210, ICNIC0.5 mg+IVATP150, ICNIC1 mg+IVATP150, and ICNIC2 mg+IVATP150 were 0.85±0.08, 0.89±0.08, 0.85±0.09, 0.84±0.08, 0.83±0.08, 0.83±0.08 (P<0.01), and 92%, 54%, 91%, 96%, 99%, 99% (P<0.01), respectively. The incidence of systolic aortic pressure drop, chest discomfort, and transient atrioventricular block increased in a dose-dependent manner after IV ATP infusion, but almost no adverse effects were observed after ICNIC2 mg. CONCLUSIONS: ICNIC2 mg produced a more pronounced hyperemia than continuous IV ATP, and might be the preferred method for assessment of FFR.

Association between absolute blood eosinophil count and CKD stages among cardiac patients.

Elevated eosinophil count was shown to be associated with the development of cholesterol embolization syndrome, a potentially life-threatening condition, after catheter-based procedures. We investigated the association between stages of chronic kidney disease (CKD) and the absolute eosinophil count (AEC) among cardiac patients. CKD stages were determined solely on the estimated glomerular filtration rate or requirement for hemodialysis. Eosinophilia is defined as an eosinophil count exceeding 500/µL. A total of 1022 patients were enrolled in the current study, and eosinophil counts (/µL) in the first through fourth eosinophil count quartiles were <88, 88 to 154, 155 to <238, and 238 ≤, respectively, and 29 patients (2.8 %) had eosinophilia. Correlation coefficient between the AEC and age was -0.188 (P = 0.001) in women and -0.042 (n.s.) in men (by Spearman's correlation test). Patients with higher CKD stages had a higher prevalence of the highest AEC quartile or eosinophilia. Logistic regression analysis using severe renal dysfunction (i.e., CKD stage 4 or 5) as the dependent variable, the highest AEC quartile had a significant positive association with an odds ratio of 1.99 (95 % confidence interval, 1.20-3.31, P < 0.01) after adjustment for sex, age, systolic blood pressure, and total white blood cell count. Similarly, after adjustment for the same variables, eosinophilia was associated with severe renal dysfunction with an odds ratio of 2.60 (95 % confidence interval, 1.08-6.26, P < 0.05). Eosinophil count was positively associated with higher CKD stages among cardiology patients, some fraction of which might be related to subclinical cholesterol embolization.

Late peri-stent contrast staining appearance due to rupture of atherogenic neointima following drug-eluting stent.

The development of peri-stent contrast staining (PSS) after coronary intervention with implantation of a stent is observed in approximately 1-3% of patients treated with drug-eluting stent. Although the cumulative incidences of late in-stent restenosis and stent thrombosis are significantly higher in lesions with PSS than in those without the finding, the mechanisms for the development of PSS have not yet been fully elucidated. In this report, we describe a case of rapid development of PSS with ulcer formation caused by rupture of atherogenic neointima, which was observed by serial optical coherence tomography examinations over 6 months. Protrusion of the stent-jailed underlying necrotic core toward the lumen by the contracting force might have resulted in formation of atherogenic neointima within the stent. Subsequently, rupture of this necrotic core induced by iatrogenic neointimal injury due to balloon dilation and dissolution of the accumulated necrotic core may have resulted in PSS formation 6 months after the procedure. These findings may be helpful for consideration of etiology and therapeutic strategy for lesions with PSS. .

Acute myocardial infarction in a patient with uncorrected tetralogy of Fallot accompanied by coronary artery ectasia: A case report.

A 63-year-old male with a medical history of uncorrected tetralogy of Fallot (TOF) presented to our hospital due to acute myocardial infarction (AMI). Emergency coronary angiography (CAG) was performed and it showed a severe thrombotic stenosis in the middle right coronary artery (RCA) and total thrombotic occlusion of the posterior descending branch of the RCA. Subsequently, percutaneous coronary artery intervention (PCI) under the guidance of intravascular ultrasound (IVUS) was performed. He was discharged on the 14th day in stable condition. Nine months after the PCI procedure, coronary computed tomography angiography was performed for follow-up, which revealed tetralogy of Fallot and complete resolution of the thrombus and ectasic coronary artery without stenosis. When he was 70 years old, he was transferred to our hospital because of recurrent AMI. As emergency CAG showed total thrombotic occlusion of the middle RCA, IVUS-guided PCI was performed. We experienced a very rare case of AMI in an adult patient with uncorrected TOF accompanied by coronary artery ectasia (CAE). To the best of our knowledge, this is the first case of AMI in an adult patient with uncorrected TOF accompanied by CAE. .

Successful percutaneous removal of dislodged ring-marker of optical coherence tomography catheter using the twisted wire technique with a guide-extension catheter: A case report.

An 81-year-old male with diabetes and hypertension was admitted to our hospital due to chest pain on exertion. Coronary angiography revealed a severe stenosis at the middle of right coronary artery (RCA). We performed percutaneous coronary intervention under the guidance of optical coherence tomography (OCT) to the lesion in the middle RCA. After balloon dilations, a drug-eluting stent was deployed to the lesion. Then, OCT examination was performed. At that time, fluoroscopy revealed a foreign body over the 0.014-inch guidewire in the distal RCA, which was the ring-marker of OCT catheter. As RCA blood flow was well preserved, percutaneous removal of the dislodged ring-marker was immediately attempted. At first, we tried to remove the dislodged ring-marker with the guide-extension catheter trapping technique. However, it failed and advanced balloon catheter made the dislodged ring-marker migrate more distally. Therefore, we tried the twisted wire technique with the guide-extension catheter and finally the dislodged ring-marker was removed with it. To the best of our knowledge, this is the first case report of a successful percutaneous removal of a dislodged ring-marker of OCT catheter using the twisted wire technique with a guide-extension catheter. .

Evaluation of repeated progression of native coronary artery stenosis by optical frequency domain imaging in a patient with essential thrombocytosis.

Essential thrombocytosis (ET) is a myeloproliferative disorder with abnormal proliferation of the megakaryocytes and is manifested clinically by the overproduction of dysfunctional platelets, leading to thrombus formation. Therefore, the accurate evaluation of the morphological features for coronary stenosis and initiation of appropriate treatment may be life-saving for ET patients. In this report, we describe a case of the rapid development of repeated stenosis in the native coronary artery in an ET patient, and optical frequency domain imaging confirmed the etiology of the stenoses. These findings may be helpful for consideration of etiology and therapeutic strategy for thrombotic complications in ET patients. .