Shoichi Kuramitsu

Incidence and Clinical Impact of Stent Fracture After Everolimus-Eluting Stent Implantation

Background—Stent fracture (SF) after drug-eluting stent implantation has recently become an important concern because of its potential association with in-stent restenosis and stent thrombosis. However, the incidence and clinical impact of SF after everolimus-eluting stent implantation remain unclear. Methods and Results—A total of 1035 patients with 1339 lesions undergoing everolimus-eluting stent implantation and follow-up angiography 6 to 9 months after index procedure were analyzed. SF was defined as complete or partial separation of the stent, as assessed by plain fluoroscopy or intravascular ultrasound during follow-up. We assessed the rates of SF and major adverse cardiac events, defined as cardiac death, myocardial infarction, stent thrombosis, and clinically driven target lesion revascularization within 9 months. SF was observed in 39 of 1339 lesions (2.9%) and in 39 of 1035 patients (3.8%). Ostial stent location and lesions with hinge motion, tortuosity, or calcification were independent predictors of SF. The rate of myocardial infarction and target lesion revascularization were significantly higher in the SF group than in the non-SF group (5.1% versus 0.4%; P=0.018 and 25.6% versus 2.0%; P<0.001, respectively). Stent thrombosis was more frequently observed in the SF group than in the non-SF group (5.1% versus 0.4%; P=0.018). Major adverse cardiac events within 9 months were significantly higher in the SF group than in the non-SF group (25.6% versus 2.3%; P<0.001). Conclusions—SF after everolimus-eluting stent implantation occurs in 2.9% of lesions and is associated with higher rate of major adverse cardiac events, driven by higher target lesion revascularization and stent thrombosis.

Incidence and Clinical Impact of Stent Fracture After the Nobori Biolimus-Eluting Stent Implantation

Background Stent fracture (SF) after drug‐eluting stent implantation has become an important concern. The aim of this study was to assess the incidence, predictors, and clinical impact of SF after biolimus‐eluting stent. Methods and Results A total of 1026 patients with 1407 lesions undergoing the Nobori biolimus‐eluting stent implantation and follow‐up angiography within 9 months after index procedure were analyzed. SF was defined as complete or partial separation of the stent, as assessed by using plain fluoroscopy, intravascular ultrasound, or optical coherence tomography during the follow‐up. We assessed the rate of SF and the cumulative incidence of clinically driven target lesion revascularization and definite stent thrombosis within 9 months. SF was observed in 58 (4.1%) of 1407 lesions and 57 (5.5%) of 1026 patients. Lesions with hinge motion (OR 8.90, 95% CI 3.84 to 20.6, P<0.001), tortuosity (OR 4.16, 95% CI 1.75 to 9.88, P=0.001), and overlapping stents (OR 2.41, 95% CI 0.95 to 6.10, P=0.06) were predictors of SF. Cumulative incidence of clinically driven target lesion revascularization within 9 months was numerically higher in the SF group than that in the non‐SF group (12.0% versus 1.0%). Cumulative incidence of definite stent thrombosis within 9 months tended to be higher in the SF group than that in the non‐SF group (1.7% versus 0.5%). Conclusions SF after biolimus‐eluting stent occurs in 4.1% of lesions and appears to be associated with clinically driven target lesion revascularization.

Vascular response to bioresorbable polymer sirolimus-eluting stent vs. permanent polymer everolimus-eluting stent at 9-month follow-up: an optical coherence tomography sub-study from the CENTURY II trial

Aims The Ultimaster bioresorbable polymer sirolimus-eluting stent (BP-SES) is a newly developed drug-eluting stent (DES) that consists of a thin-strut, cobalt chromium with bioresorbable polymer coated only albuminally. We sought to compare tissue coverage in coronary lesions treated with BP-SES with the XIENCE permanent polymer everolimus-eluting stent (PP-EES) using optical coherence tomography (OCT). Methods and results A total of 36 patients participated in the CENTURY II trial in our institution and were randomly assigned to BP-SES (n = 15) and PP-EES (n = 21). Of these, 27 patients (13 BP-SES and 14 PP-EES) underwent OCT at 9-month follow-up. Tissue coverage and apposition were assessed on each strut, and the results in both groups were compared using multilevel logistic or linear regression models with random effects at three levels: patient, lesion, and struts. A total of 6450 struts (BP-SES, n = 2951; PP-EES, n = 3499) were analysed. Thirty and 79 uncovered struts (1.02 and 2.26%, P = 0.35), and 3 and 4 malapposed struts (0.10 and 0.11%, P = 0.94) were found in BP-SES and PP-EES groups, respectively. Mean neointimal thickness did not significantly differ between both groups (110 ± 10 vs. 93 ± 10 µm, P = 0.22). No significant differences in per cent neointimal volume obstruction (13.2 ± 4.6 vs. 10.5 ± 4.9%, P = 0.14) or other areas-volumetric parameters were detected between both groups. Conclusion BP-SES shows an excellent vascular healing response at 9-month follow-up, which is similar to PP-EES.

Impact of post-challenge hyperglycemia on clinical outcomes in japanese patients with stable angina undergoing percutaneous coronary intervention

BackgroundPost-challenge hyperglycemia (PH) is well-established as one of risk factors for coronary artery disease. However, it remains unclear whether PH affects clinical outcomes in patients with stable angina undergoing percutaneous coronary intervention (PCI).MethodsA total of 828 patients with stable angina undergoing PCI were retrospectively analyzed. Of these, 452 patients with previously diagnosed diabetes mellitus (DM) or fasting plasma glucose (PG) ≥126 mg/dl and HbA1c ≥6.5% were defined as known DM. The remaining 376 patients were divided into the two groups according to 2-h PG: PH (2-h PG ≥140 mg/dl, n=236) and normal glucose tolerance (NGT, 2-h PG <140 mg/dl, n=140). We assessed the rate of major adverse cardiovascular events (MACE), defined as a composite of cardiovascular death, myocardial infarction, stroke, and clinically-driven revascularization.ResultsDuring the median follow-up of 4.3 years, the MACE rate was significantly higher in the DM and PH groups than the NGT group (39.3% vs. 20.7%, P <0.001; 31.4% vs. 20.7%, P=0.044, respectively). Compared with the NGT group, the cumulative incidence of revascularization was significantly higher in the DM group (35.1% vs. 18.5%, P <0.001) and tended to be higher in the PH group (27.1% vs. 18.5%, P=0.067). In the multivariate analysis, known DM (Hazard ratio [HR]: 2.16, 95% confidence interval (CI): 1.49-3.27, P < 0.001), PH (HR: 1.62, 95% CI: 1.07-2.53, P = 0.023), LDL-C >100 mg/dl (HR: 1.62, 95% CI: 1.26 to 2.10, P < 0.001), and previous stroke (HR: 1.47, 95% CI: 1.03-2.04, P = 0.034) were predictors of MACE.ConclusionPH is associated with future cardiovascular events in patients with stable angina undergoing PCI.

Two-Year Clinical Outcomes of Newer-Generation Drug-Eluting Stent Implantation Following Rotational Atherectomy for Heavily Calcified Lesions

BACKGROUND Clinical outcomes of implantation of the newer-generation drug-eluting stent (DES) following rotational atherectomy for heavily calcified lesions remain unclear in the real-world setting. METHODSANDRESULTS We enrolled 252 consecutive patients (273 lesions) treated with newer-generation DES following rotational atherectomy. The primary endpoint was the cumulative 2-year incidence of major adverse cardiovascular events (MACE), defined as cardiac death, myocardial infarction, clinically-driven target lesion revascularization, and definite stent thrombosis. Complete clinical follow-up information at 2-year was obtained for all patients. The mean age was 73.2±9.0 years and 155 patients (61.5%) were male. Cumulative 2-year incidence of MACE (cardiac death, myocardial infarction, clinically-driven target lesion revascularization and definite stent thrombosis) was 20.3% (7.0%, 2.1%, 18.1% and 2.1%, respectively). Predictors of MACE were presenting with acute coronary syndrome (hazard ratio [HR]: 3.80, 95% confidence interval [CI]: 1.29-11.2, P=0.02), hemodialysis (HR: 1.93, 95% CI: 1.04-3.56, P=0.04) and previous coronary artery bypass graft (HR: 2.26, 95% CI: 1.02-5.00, P=0.045). CONCLUSIONS PCI for calcified lesions requiring rotational atherectomy is still challenging even in the era of newer-generation DES.

Long-term coronary arterial response to biodegradable polymer biolimus-eluting stents in comparison with durable polymer sirolimus-eluting stents and bare-metal stents: Five-year follow-up optical coherence tomography study

OBJECTIVE The long-term coronary arterial response of biodegradable polymer biolimus-eluting stents (BES) remains unclear. We sought to evaluate the coronary arterial response of biodegradable polymer BES at 5 years after stent implantation using optical coherence tomography (OCT) as compared with that of durable polymer sirolimus-eluting stents (SES) and bare-metal stents (BMS). METHODS Five-year follow-up OCT was performed in 30 patients with 33 stents (10 with 12 BES; 10 with 11 SES; 10 with 10 BMS). Quantitative parameters and qualitative characteristics of the neointima were evaluated. A total of 5178 struts (BES, n = 2056; SES, n = 1410; BMS, n = 1712) were analyzed. RESULTS Uncovered struts were found in 15 out of 2055 struts in the BES (weighted estimate 0.01%, 95% confidence intervals [CI]: 0.00-0.33%) and 54 out of 1410 struts in the SES (0.11%, 95% CI: 0.00-3.33%) (odds ratio [OR] 0.12, 95% CI: 0.01-1.95, p = 0.13). None of 1712 struts were uncovered in the BMS. Cross-sectional qualitative analysis of neointimal tissue showed that the frequency of lipid-laden neointima tended to be lower in the BES (2.26%, 95% CI: 0.38-12.3%) compared with the SES (9.90%, 95% CI: 4.37-20.9%; OR 0.21, 95% CI 0.03-1.16, p = 0.07), and was similar to the BMS (2.23%, 95% CI: 0.54-8.74%; OR 0.98, 95% CI 0.13-7.14, p = 0.98). CONCLUSIONS Biodegradable polymer BES shows a favorable coronary arterial response compared with SES, but different response with BMS at 5 years follow-up. The observed frequency of in-stent neoatherosclerosis within BES was similar to BMS and tended to be lower than SES.

Vascular response after Zilver PTX stent implantation for superficial femoral artery lesions: serial optical coherence tomography findings at 6 and 12 months.

Purpose: To compare the vascular response after paclitaxel-coated nitinol drug-eluting stent (Zilver PTX) implantation for superficial femoral artery lesions after 6 and 12 months using optical coherence tomography (OCT). Methods: Serial OCT examinations were performed in 5 patients (4 men; mean age 78.4±6.8 years) with 9 Zilver PTX stents at 6- and 12-month follow-up. Variables evaluated included neointimal thickness and apposition on each strut, the incidence of extrastent lumen (ESL), peristrut low-intensity area (PLIA), and neovascularization at 1-mm intervals. Results: A total of 249 matched cross-section images were evaluated and included 4788 and 4826 struts at 6 and 12 months, respectively. Mean neointimal thickness significantly increased from 480 to 540 µm between 6 and 12 months (p<0.001). The percentage of uncovered struts tended to decrease at 12 months (3% vs. 2.3%, p=0.054), whereas the percentage of malapposed struts were similar at both examinations (0.2% vs. 0.2%, p>0.99). Although the incidence of ESL in cross sections was not different (35% vs. 31%, p=0.29), median ESL area significantly increased from 6 to 12 months [0.12 (0.04–0.36) vs. 0.31 (0.14–0.59) mm2, p=0.003)]. The presence of PLIA (29% vs. 44%, p<0.001) and neovascularization (14% vs. 27%, p<0.001) increased from 6 to 12 months. Conclusion: These findings suggest that delayed vascular healing and persistent peristent inflammation may be present even at 12 months after Zilver PTX implantation.

Very Long-Term (15 to 23 Years) Outcomes of Successful Balloon Angioplasty Compared With Bare Metal Coronary Stenting

Background Target lesion revascularization (TLR) continues to occur beyond 4 years after bare metal stent (BMS) implantation. However, long-term outcomes after balloon angioplasty (BA) compared with BMS are currently unknown. Methods and Results From 1989 to 1990, 659 patients (748 lesions) underwent successful BA with final balloon ≥3.0 mm excluding patients with acute myocardial infarction and were compared with 405 patients (424 lesions) with BMS implantation from June 1990 to 1993. Cumulative incidences of death and target lesion thrombosis (>1 year) were similar between the BA group and the BMS group (44.4% versus 45.4%, P=0.60; and 1.5% versus 0.7%, P=0.99; respectively). Cumulative incidence of TLR during overall follow-up was significantly higher after BA than after BMS implantation (44.6% versus 36.0%, P<0.001), whereas cumulative incidence of late TLR (>4 years) tended to be lower in the BA group than in the BMS group (16.3% versus 21.4%, P=0.16). Cumulative incidence of late TLR after BA was significantly lower in patients with small percent diameter stenosis (%DS) at early follow-up angiography compared with large %DS (14.5% versus 28.0%, P=0.02). In lesions with serial angiography, late lumen loss from early (6 to 14 months) to long-term (4 to 10 years) follow-up angiography was significantly smaller in the BA group (n=42) than in the BMS group (n=55) (−0.08±0.45 mm versus 0.11±0.46 mm, P=0.047). Conclusions Compared with BMS implantation, BA was associated with a trend for less late TLR beyond 4 years and with significantly smaller late lumen loss from early to long-term follow-up angiography.

Association of localized hypersensitivity and in-stent neoatherosclerosis with the very late drug-eluting stent thrombosis.

Background Localized hypersensitivity reaction, delayed arterial healing, and neoatherosclerosis inside the stent have been suggested as the underlying pathologic mechanisms of very late stent thrombosis (VLST) of drug-eluting stent (DES). The present study sought to explore the prevalence of inflammatory cell infiltrates and evidence for fragments of atherosclerotic plaques in the aspirated thrombi in patients with DES VLST. Methods and Results From April 2004 to September 2012, 48 patients with stent thrombosis (ST) of DES underwent thrombus aspiration with retrieved material sufficient for the histopathologic analysis; early ST (EST, within 30 days): N = 17, late ST (LST, between 31 and 365 days): N = 7, and very late ST (VLST, >1 year): N = 24. Eosinophil fraction in the aspirated thrombi was significantly higher in patients with VLST (8.2±5.7%) as compared with those with EST (4.3±3.0%) and LST (5.5±3.8%) (P = 0.03). Eosinophil fraction in the aspirated thrombi was significantly higher in 12 VLST patients with angiographic peri-stent contrast staining (PSS) and/or incomplete stent apposition (ISA) by intravascular ultrasound than in 12 VLST patients without PSS or ISA (10.6±6.1% versus 5.8±4.1%, P = 0.03). Evidences for fragments of atherosclerotic plaques in the aspirated thrombi were observed only in 3 (13%) out of 24 patients with DES VLST. Conclusions Eosinophil fraction in the aspirated thrombi was significantly higher in patients with DES VLST as compared with those with EST and LST. Evidences for fragments of atherosclerotic plaques were relatively uncommon in patients with DES VLST.

Difference of Tissue Characteristics Between Early and Late Restenosis After Second-Generation Drug-Eluting Stents Implantation ― An Optical Coherence Tomography Study ―

BACKGROUND The mechanism and time course of in-stent restenosis (ISR) after implantation of second-generation DES have not yet been fully elucidated. We sought to evaluate the differences in tissue characteristics between the different phases of ISR after second-generation DES implantation using optical coherence tomography (OCT).Methods and Results:From June 2010 to December 2015, 324 consecutive patients with 337 ISR lesions underwent OCT. Of these, we analyzed 53 lesions in 53 patients who had their first ISR after second-generation DES implantation and underwent OCT before any procedures. According to the timing of ISR, the patients were divided into the early group (within 1 year: E-ISR, n=30) and late group (beyond 1 year: L-ISR, n=23). Quantitative parameters and qualitative characteristics of the neointima were evaluated. In the minimum lumen area site analysis, the E-ISR group had more frequently homogeneous intima than the L-ISR group (26.7% vs. 4.4%, P=0.02). The frequencies of neointima with lipid-laden, thin-cap fibroatheroma, neovascularization and macrophage infiltration were significantly higher in the L-ISR group than in the E-ISR group (30.0% vs. 69.6%, P<0.01; 0.0% vs. 26.1%, p <0.01; 6.7% vs. 26.1%, P=0.049; 3.3% vs. 26.1%, P=0.01, respectively). CONCLUSIONS Neointimal tissue characteristics differed between E-ISR and L-ISR after second-generation DES implantation. E-ISR was mainly caused by neointimal hyperplasia, whereas neoatherosclerosis was the main mechanism of L-ISR.