Kazushige Kadota

Antiplatelet Therapy and Stent Thrombosis After Sirolimus-Eluting Stent Implantation

Background— The influences of antiplatelet therapy discontinuation on the risk of stent thrombosis and long-term clinical outcomes after drug-eluting stent implantation have not yet been addressed adequately. Methods and Results— In an observational study in Japan, 2-year outcomes were assessed in 10 778 patients undergoing sirolimus-eluting stent implantation. Data on status of antiplatelet therapy during follow-up were collected prospectively. Incidences of definite stent thrombosis were 0.34% at 30 days, 0.54% at 1 year, and 0.77% at 2 years. Thienopyridine use was maintained in 97%, 62%, and 50% of patients at 30 days, 1 year, and 2 years, respectively. Patients who discontinued both thienopyridine and aspirin had a significantly higher rate of stent thrombosis than those who continued both in the intervals of 31 to 180 days, 181 to 365 days, and 366 to 548 days after stent implantation (1.76% versus 0.1%, P<0.001; 0.72% versus 0.07%, P=0.02; and 2.1% versus 0.14%, P=0.004, respectively). When discontinuation of aspirin was taken into account, patients who discontinued thienopyridine only did not have an excess of stent thrombosis in any of the time intervals studied. Adjusted rates of death or myocardial infarction at 24 months were 4.1% for patients taking thienopyridine and 4.1% for patients not taking thienopyridine (P=0.99) in the 6-month landmark analysis. Conclusions— Discontinuation of both thienopyridine and aspirin, but not discontinuation of thienopyridine therapy only, was associated with an increased risk of stent thrombosis. Landmark analysis did not suggest an apparent clinical benefit of thienopyridine use beyond 6 months after sirolimus-eluting stent implantation.

Effectiveness of paclitaxel-eluting balloon catheter in patients with sirolimus-eluting stent restenosis.

OBJECTIVES The aim of this study was to investigate the efficacy of a paclitaxel-eluting balloon (PEB) for the treatment of sirolimus-eluting stent (SES) restenosis. BACKGROUND Because drug-eluting stents (DES) are being used in increasingly complicated settings, DES restenosis is no longer an uncommon phenomenon, and its optimal treatment is unknown. METHODS This study was a prospective single-blind randomized trial conducted in 50 patients with SES restenosis. Patients were randomly assigned to a PEB group (n = 25) or a conventional balloon angioplasty (BA) group (n = 25). The primary end point was late lumen loss at 6-month follow-up. Secondary end points included the rate of binary restenosis (in-segment analysis) and major adverse cardiac events (MACE) at 6-month follow-up. RESULTS At 6-month angiographic follow-up (follow-up rate: 94%), in-segment late lumen loss was lower in the PEB group than in the BA group (0.18 ± 0.45 mm vs. 0.72 ± 0.55 mm; p = 0.001). The incidence of recurrent restenosis (8.7% vs. 62.5%; p = 0.0001) and target lesion revascularization (4.3% vs. 41.7%; p = 0.003) was also lower in the PEB group than in the BA group. The cumulative MACE-free survival was significantly better in the PEB group than in the BA group (96% vs. 60%; p = 0.005). CONCLUSIONS In patients with SES restenosis, PEB provided much better clinical, angiographic outcomes than conventional BA.

Biodegradable Polymer Biolimus-Eluting Stent Versus Durable Polymer Everolimus-Eluting Stent : A Randomized, Controlled, Noninferiority Trial

OBJECTIVES NEXT (NOBORI Biolimus-Eluting Versus XIENCE/PROMUS Everolimus-Eluting Stent Trial) was designed for evaluating the noninferiority of a biolimus-eluting stent (BES) relative to an everolimus-eluting stent (EES) in terms of target lesion revascularization (TLR) at 1 year. BACKGROUND Efficacy and safety data comparing biodegradable polymer BES with durable polymer cobalt-chromium EES are currently limited. METHODS The NEXT trial is a prospective, multicenter, randomized, open-label, noninferiority trial comparing BES with EES. Between May and October 2011, 3,235 patients were randomly assigned to receive either BES (n = 1,617) or EES (n = 1,618). RESULTS At 1 year, the primary efficacy endpoint of TLR occurred in 67 patients (4.2%) in the BES group, and in 66 patients (4.2%) in the EES group, demonstrating noninferiority of BES relative to EES (p for noninferiority <0.0001, and p for superiority = 0.93). Cumulative incidence of definite stent thrombosis was low and similar between the 2 groups (0.25% vs. 0.06%, p = 0.18). An angiographic substudy enrolling 528 patients (BES: n = 263, and EES: n = 265) demonstrated noninferiority of BES relative to EES regarding the primary angiographic endpoint of in-segment late loss (0.03 ± 0.39 mm vs. 0.06 ± 0.45 mm, p for noninferiority <0.0001, and p for superiority = 0.52) at 266 ± 43 days after stent implantation. CONCLUSIONS One-year clinical and angiographic outcome after BES implantation was noninferior to and not different from that after EES implantation in a mostly stable coronary artery disease population. One-year clinical outcome after both BES and EES use was excellent, with a low rate of TLR and extremely low rate of stent thrombosis.

Comparison of Everolimus-Eluting and Sirolimus-Eluting Coronary Stents 1-Year Outcomes from the Randomized Evaluation of Sirolimus-Eluting Versus Everolimus-Eluting Stent Trial (RESET)

Background— Several recent randomized trials comparing everolimus-eluting stent (EES) and sirolimus-eluting stent (SES) reported similar outcomes. However, only 1 trial was powered for a clinical end point, and no trial was powered for evaluating target-lesion revascularization. Methods and Results— Randomized Evaluation of Sirolimus-eluting versus Everolimus-eluting stent Trial is a prospective multicenter randomized open-label trial comparing EES with SES in Japan. The trial was powered for evaluating noninferiority of EES relative to SES in terms of target-lesion revascularization. From February and July 2010, 3197 patients were randomly assigned to receive either EES (1597 patients) or SES (1600 patients). At 1 year, the primary efficacy end point of target-lesion revascularization occurred in 65 patients (4.3%) in the EES group and in 76 patients (5.0%) in the SES group, demonstrating noninferiority of EES to SES ( P noninferiority<0.0001, and P superiority=0.34). Cumulative incidence of definite stent thrombosis was low and similar between the 2 groups (0.32% versus 0.38%, P =0.77). An angiographic substudy enrolling 571 patients (EES, 285 patients and SES, 286 patients) demonstrated noninferiority of EES relative to SES regarding the primary angiographic end point of in-segment late loss (0.06±0.37 mm versus 0.02±0.46 mm, P noninferiority<0.0001, and P superiority=0.24) at 278±63 days after index stent implantation. Conclusions— One-year clinical and angiographic outcome after EES implantation was noninferior to and not different from that after SES implantation in a stable coronary artery disease population with relatively less complex coronary anatomy. One-year clinical outcome after both EES and SES use was excellent with a low rate of target-lesion revascularization and a very low rate of stent thrombosis. Clinical Trial Registration— URL: . Unique identifier: [NCT01035450][1]. # Clinical Perspective {#article-title-27} [1]: /lookup/external-ref?link_type=CLINTRIALGOV&access_num=NCT01035450&atom=%2Fcirculationaha%2F126%2F10%2F1225.atomBackground— Several recent randomized trials comparing everolimus-eluting stent (EES) and sirolimus-eluting stent (SES) reported similar outcomes. However, only 1 trial was powered for a clinical end point, and no trial was powered for evaluating target-lesion revascularization. Methods and Results— Randomized Evaluation of Sirolimus-eluting versus Everolimus-eluting stent Trial is a prospective multicenter randomized open-label trial comparing EES with SES in Japan. The trial was powered for evaluating noninferiority of EES relative to SES in terms of target-lesion revascularization. From February and July 2010, 3197 patients were randomly assigned to receive either EES (1597 patients) or SES (1600 patients). At 1 year, the primary efficacy end point of target-lesion revascularization occurred in 65 patients (4.3%) in the EES group and in 76 patients (5.0%) in the SES group, demonstrating noninferiority of EES to SES (Pnoninferiority<0.0001, and Psuperiority=0.34). Cumulative incidence of definite stent thrombosis was low and similar between the 2 groups (0.32% versus 0.38%, P=0.77). An angiographic substudy enrolling 571 patients (EES, 285 patients and SES, 286 patients) demonstrated noninferiority of EES relative to SES regarding the primary angiographic end point of in-segment late loss (0.06±0.37 mm versus 0.02±0.46 mm, Pnoninferiority<0.0001, and Psuperiority=0.24) at 278±63 days after index stent implantation. Conclusions— One-year clinical and angiographic outcome after EES implantation was noninferior to and not different from that after SES implantation in a stable coronary artery disease population with relatively less complex coronary anatomy. One-year clinical outcome after both EES and SES use was excellent with a low rate of target-lesion revascularization and a very low rate of stent thrombosis. Clinical Trial Registration— URL: http://www.clinicaltrials.gov. Unique identifier: NCT01035450.

Incidence, Risk Factors, and Clinical Sequelae of Angiographic Peri-Stent Contrast Staining After Sirolimus-Eluting Stent Implantation

Background— We have noted abnormal angiographic findings—at the sites of drug-eluting stent implantation, suggesting contrast staining outside the stent struts—that do not fulfill the classic definition of coronary artery aneurysm. We propose a new term, peri-stent contrast staining (PSS), for these abnormal angiographic findings and assess their incidence, risk factors, and clinical sequelae. Methods and Results— Peri-stent contrast staining was defined as contrast staining outside the stent contour extending to ≥20% of the stent diameter. The study population consisted of 3081 lesions (1998 patients) that were treated exclusively with sirolimus-eluting stents and were evaluated by follow-up angiography within 12 months after sirolimus-eluting stent implantation in a single center. Late acquired PSS was observed in 58 lesions (1.9%) in 49 patients (2.5%). Independent risk factors of PSS included chronic total occlusion, whereas negative risk factors for PSS were left circumflex coronary artery lesion and in-stent restenosis lesion. Stent fracture was more frequently observed in lesions with PSS than in lesions without PSS (43.1% versus 5.4%, P<0.0001). Excluding 269 lesions with target-lesion revascularization within 12 months, the study population for long-term follow-up consisted of 51 lesions (42 patients) with PSS and 2761 lesions (1751 patients) without PSS. Cumulative incidence of target-lesion revascularization and definite very late stent thrombosis at 3 years in the PSS group was higher than that in the non-PSS group (15.0% versus 6.5%, and 8.2% versus 0.2%, respectively). Conclusions— Peri-stent contrast staining found within 12 months after sirolimus-eluting stent implantation appeared to be associated with subsequent target-lesion revascularization and very late stent thrombosis.

Incidence and Risk Factors of Late Target Lesion Revascularization After Sirolimus-Eluting Stent Implantation (3-Year Follow-Up of the j-Cypher Registry)

It yet has not been clarified whether there is a late catch-up phenomenon in target lesion revascularization (TLR) after sirolimus-eluting stent (SES) compared to bare metal stent (BMS) implantation. In 12,824 patients enrolled in the j-Cypher Registry, incidences of early (within first year) and late (1 year to 3 years) TLR were compared between 17,050 lesions treated with SESs and 1,259 lesions treated with BMSs. Incidences of TLR in SES-treated lesions were 5.7% at 1 year, 8.1% at 2 years, and 10.0% at 3 years, whereas those in BMS-treated lesions were 14.2%, 15.5%, and 15.5%, respectively (p <0.0001, log-rank test). Incidences of late TLR were significantly higher with SESs compared to BMSs (2.6% vs 1.4% at 2 years and 4.5% vs 1.4% at 3 years, p = 0.0007, log-rank test). A multivariable logistic regression model identified 7 independent risk factors for late TLR at 3 years after SES implantation: hemodialysis, low estimated glomerular filtration rate, ostial right coronary artery, lesion length >or=30 mm, 2 stents for bifurcation, American Heart Association/American College of Cardiology type B2/C, and vessel size <2.5 mm. Of these, 5 factors were common to those for early TLR. In conclusion, a late catch-up phenomenon was observed as indicated by the increasing incidence of late TLR after SES, but not after BMS, implantation. Risk factors for late TLR were generally common to those for early TLR.

Late Adverse Events After Implantation of Sirolimus-Eluting Stent and Bare-Metal Stent Long-Term (5–7 Years) Follow-Up of the Coronary Revascularization Demonstrating Outcome Study-Kyoto Registry Cohort-2

Background—Late adverse events such as very late stent thrombosis (VLST) or late target-lesion revascularization (TLR) after first-generation sirolimus-eluting stents (SES) implantation have not been yet fully characterized at long term in comparison with those after bare-metal stent (BMS) implantation. Methods and Results—Among 13 058 consecutive patients undergoing first percutaneous coronary intervention in the Coronary REvascularization Demonstrating Outcome study-Kyoto registry Cohort-2, 5078 patients were treated with SES only, and 5392 patients were treated with BMS only. During 7-year follow-up, VLST and late TLR beyond 1 year after SES implantation occurred constantly and without attenuation at 0.24% per year and at 2.0% per year, respectively. Cumulative 7-year incidence of VLST was significantly higher in the SES group than that in the BMS group (1.43% versus 0.68%, P<0.0001). However, there was no excess of all-cause death beyond 1 year in the SES group as compared with that in the BMS group (20.8% versus 19.6%, P=0.91). Cumulative incidences of late TLR (both overall and clinically driven) were also significantly higher in the SES group than in the BMS group (12.0% versus 4.1%, P<0.0001 and 8.5% versus 2.6%, P<0.0001, respectively), leading to late catch-up of the SES group to the BMS group regarding TLR through the entire 7-year follow-up (18.8% versus 25.2%, and 10.6% versus 10.2%, respectively). Clinical presentation as acute coronary syndrome was more common at the time of late SES TLR compared with early SES TLR (21.2% and 10.0%). Conclusions—Late catch-up phenomenon regarding stent thrombosis and TLR was significantly more pronounced with SES than that with BMS. This limitation should remain the target for improvements of DES technology.

Optical Coherence Tomography Findings in Lesions After Sirolimus-Eluting Stent Implantation With Peri-Stent Contrast Staining

Background—We have sometimes noted abnormal angiographic coronary dilatation, <50% of the reference vessel, at the site of sirolimus-eluting stent implantation, suggesting contrast staining outside the stent struts and named this finding peri-stent contrast staining (PSS). Little was known about optical coherence tomography findings of lesions with PSS. Methods and Results—Between May 2008 and March 2010, we performed optical coherence tomography for 90 in-stent restenosis lesions after sirolimus-eluting stent implantation. We found PSS in 20 of the 90 lesions by coronary angiography. The differences in optical coherence tomography findings, including incomplete stent apposition, multiple interstrut hollows (MIH), strut coverage, and thrombus, were compared between lesions with PSS and those without PSS. PSS is defined as contrast staining outside the stent contour extending to >20% of the stent diameter measured by quantitative coronary angiography. MIH is defined as multiple hollows (the maximum depth >0.5 mm) existing between and outside well-apposed stent struts. Both incomplete stent apposition (60.0% versus 10%; P<0.001) and MIH (85.0% versus 25.7%; P<0.001) were frequently observed in lesions with PSS than in lesions without PSS. Among the 20 lesions with PSS, there was only 1 lesion in which we found neither MIH nor incomplete stent apposition, but only minor dissection. Uncovered struts (11.6% versus 3.9%; P=0.001), malapposed struts (2.0% versus 0.0%; P<0.001), and red thrombus (35% versus 10%; P=0.012) were frequently observed in lesions with PSS than in lesions without PSS. Conclusions—PSS might be closely associated with 2 different optical coherence tomography findings, MIH and incomplete stent apposition, in lesions after sirolimus-eluting stent implantation.

Duration of Dual Antiplatelet Therapy and Long-Term Clinical Outcome After Coronary Drug-Eluting Stent Implantation Landmark Analyses From the CREDO-Kyoto PCI/CABG Registry Cohort-2

Background— Optimal duration of dual antiplatelet therapy (DAPT) after drug-eluting stent (DES) implantation has not been yet fully elucidated. Methods and Results— We assessed the influence of prolonged thienopyridine therapy on clinical outcomes with landmark analysis at 4 and 13 months after DES implantation. Among 6802 patients with at least 1 DES implantation in the CREDO-Kyoto Registry Cohort-2, 6309 patients (on thienopyridine, 5438 patients; off thienopyridine, 871 patients) and 5901 patients (on thienopyridine, 4098 patients; off thienopyridine, 1803 patients) were eligible for the 4- and 13-month landmark analyses, respectively. The majority of patients had stable coronary artery disease (73%) and received sirolimus-eluting stents (93%), and approximately 90% of thienopyridine was ticlopidine. Patients taking thienopyridine had more complex comorbidities and more complex lesion and procedural characteristics as compared with patients not taking thienopyridine. After adjusting for confounders, thienopyridine use was not associated with decreased risk for death/myocardial infarction/stroke (hazard ratio [HR], 1.13; 95% confidence interval [CI], 0.89–1.43, P=0.32 in the 4-month landmark analysis; HR, 1.14; 95% CI, 0.90–1.45, P=0.29 in the 13-month landmark analysis, respectively), whereas the risk for GUSTO moderate/severe bleeding tended to be higher in patients taking thienopyridine (HR, 1.51; 95% CI, 1.00–2.23, P=0.049 in the 4-month landmark analysis; HR, 1.44; 95% CI, 0.99–2.09, P=0.057 in the 13-month landmark analysis, respectively). Conclusions— Prolonged thienopyridine therapy beyond 4 and 13 months appeared not to be associated with reduction in ischemic events but to be associated with a trend toward increased bleeding. Optimal duration of DAPT after DES implantation might be shorter than the currently recommended 1-year interval.

A Kir3.4 mutation causes Andersen–Tawil syndrome by an inhibitory effect on Kir2.1

Objective: To identify other causative genes for Andersen–Tawil syndrome, which is characterized by a triad of periodic paralysis, cardiac arrhythmia, and dysmorphic features. Andersen–Tawil syndrome is caused in a majority of cases by mutations in KCNJ2, which encodes the Kir2.1 subunit of the inwardly rectifying potassium channel. Methods: The proband exhibited episodic flaccid weakness and a characteristic TU-wave pattern, both suggestive of Andersen–Tawil syndrome, but did not harbor KCNJ2 mutations. We performed exome capture resequencing by restricting the analysis to genes that encode ion channels/associated proteins. The expression of gene products in heart and skeletal muscle tissues was examined by immunoblotting. The functional consequences of the mutation were investigated using a heterologous expression system in Xenopus oocytes, focusing on the interaction with the Kir2.1 subunit. Results: We identified a mutation in the KCNJ5 gene, which encodes the G-protein–activated inwardly rectifying potassium channel 4 (Kir3.4). Immunoblotting demonstrated significant expression of the Kir3.4 protein in human heart and skeletal muscles. The coexpression of Kir2.1 and mutant Kir3.4 in Xenopus oocytes reduced the inwardly rectifying current significantly compared with that observed in the presence of wild-type Kir3.4. Conclusions: We propose that KCNJ5 is a second gene causing Andersen–Tawil syndrome. The inhibitory effects of mutant Kir3.4 on inwardly rectifying potassium channels may account for the clinical presentation in both skeletal and heart muscles.