Mitsuru Abe

Predicting Successful Guidewire Crossing Through Chronic Total Occlusion of Native Coronary Lesions Within 30 Minutes : The J-CTO (Multicenter CTO Registry in Japan) Score as a Difficulty Grading and Time Assessment Tool

OBJECTIVES This study sought to establish a model for grading lesion difficulty in interventional chronic total occlusion (CTO) treatment. BACKGROUND Owing to uncertainty of success of the procedure and difficulties in selecting suitable cases for treatment, performance of interventional CTO remains infrequent. METHODS Data from 494 native CTO lesions were analyzed. To eliminate operator bias, the objective parameter of successful guidewire crossing within 30 min was set as an end point, instead of actual procedural success. All observations were randomly assigned to a derivation set and a validation set at a 2:1 ratio. The J-CTO (Multicenter CTO Registry of Japan) score was determined by assigning 1 point for each independent predictor of this end point and summing all points accrued. This value was then used to develop a model stratifying all lesions into 4 difficulty groups: easy (J-CTO score of 0), intermediate (score of 1), difficult (score of 2), and very difficult (score of ≥ 3). RESULTS The set end point was achieved in 48.2% of lesions. Independent predictors included calcification, bending, blunt stump, occlusion length >20 mm, and previously failed lesion. Easy, intermediate, difficult, and very difficult groups, stratified by J-CTO score, demonstrated stepwise, proportioned, and highly reproducible differences in probability of successful guidewire crossing within 30 min (87.7%, 67.1%, 42.4%, and 10.0% in the derivation set and 92.3%, 58.3%, 34.8%, and 22.2% in the validation set, respectively). Areas under receiver-operator characteristic curves were comparable (derivation: 0.82 vs. validation: 0.76). CONCLUSIONS This model predicted the probability of successful guidewire crossing within 30 min very well and can be applied for difficulty grading.

In-Hospital Outcomes of Contemporary Percutaneous Coronary Intervention in Patients With Chronic Total Occlusion: Insights From the J-CTO Registry (Multicenter CTO Registry in Japan)

OBJECTIVES Our aim was to investigate in-hospital outcomes of percutaneous coronary intervention (PCI) of chronic total occlusion (CTO) using contemporary techniques. BACKGROUND Despite its increasing popularity and technical complexity, clinical outcomes of PCI for CTO using contemporary techniques have not been adequately evaluated. METHODS The J-CTO registry (multicenter CTO registry in Japan) is a large scale, multicenter registry enrolling consecutive patients undergoing PCI for CTO from 12 Japanese centers. In-hospital clinical outcomes were evaluated in 498 patients with 528 CTO lesions. RESULTS Multiple wiring strategies were frequently attempted (parallel wiring 31% and retrograde approach 25%) with relatively long guidewire manipulation time (median 30 min). Utilizing these complex strategies, high procedural success rates (88.6% in the first attempt cases and 68.5% in the retry cases) were accomplished. In-hospital adverse event rates were strikingly low (cardiac death 0.2%, Q-wave myocardial infarction 0.2%, and stroke 0%). Potential disadvantages of these procedures, including a large amount of contrast volume (median 293 ml) and long fluoroscopic time (median 45 min), were not associated with serious clinical sequelae (contrast induced nephropathy 1.2% and radiation dermatitis 0%). Although coronary perforations were documented frequently by angiography (antegrade 7.2% and retrograde 13.6%), clinically significant perforation resulting in cardiac tamponade was rare (0.4%). CONCLUSIONS Most CTO lesions can be safely and successfully treated with PCI utilizing contemporary advanced techniques. Invasiveness and potential risks of these strategies, which have been the greatest concerns of CTO treatment, may be acceptable in the majority of cases considering the actual incidences of related adverse events and the procedural success rates.

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.

Calcineurin-GATA-6 pathway is involved in smooth muscle-specific transcription.

Intracellular calcium is one of the important signals that initiates the myogenic program. The calcium-activated phosphatase calcineurin is necessary for the nuclear import of the nuclear factor of activated T cell (NFAT) family members, which interact with zinc finger GATA transcription factors. Whereas GATA-6 plays a role in the maintenance of the differentiated phenotype in vascular smooth muscle cells (VSMCs), it is unknown whether the calcineurin pathway is associated with GATA-6 and plays a role in the differentiation of VSMCs. The smooth muscle–myosin heavy chain (Sm-MHC) gene is a downstream target of GATA-6, and provides a highly specific marker for differentiated VSMCs. Using immunoprecipitation Western blotting, we showed that NFATc1 interacted with GATA-6. Consistent with this, NFATc1 further potentiated GATA-6–activated Sm-MHC transcription. Induction of VSMCs to the quiescent phenotype caused nuclear translocation of NFATc1. In differentiated VSMCs, blockage of calcineurin down-regulated the amount of GATA-6-DNA binding as well as the expression of Sm-MHC and its transcriptional activity. These findings demonstrate that the calcineurin pathway is associated with GATA-6 and is required for the maintenance of the differentiated phenotype in VSMCs.

Current status of clinical background of patients with atrial fibrillation in a community-based survey:The Fushimi AF Registry

BACKGROUND Atrial fibrillation (AF) increases the risks of stroke and death, and the prevalence of AF is increasing significantly. Until recently, warfarin was the only oral anticoagulant for stroke prevention, but novel anticoagulants are now under development. METHODS AND RESULTS The Fushimi AF Registry is a community-based survey of AF patients. We aimed to enroll all of the AF patients in Fushimi-ku, which is located at the southern end of the city of Kyoto. Fushimi-ku is densely populated with a total population of 283,000, and is assumed to represent a typical urban community in Japan. On the basis of the general prevalence of AF in the Japanese (0.6%), we estimated the total number of AF patients as 1700. A total of 76 institutions, a large proportion of which were private clinics, participated in the study. At present, we have enrolled 3183 patients from March 2011 to June 2012 (approximately 1.12% of total population). The mean age was 74.2±11.0 years, and 59.3% of subjects were male. The mean body weight was 58.5±13.2 kg, and the proportions with a body weight of less than 50 kg and 60 kg were 25.7% and 55.0%, respectively. The type of AF was paroxysmal in 46.0%, persistent in 7.3%, and permanent in 46.7%. Major co-existing diseases were hypertension (60.6%), heart failure (27.9%), diabetes (23.2%), stroke (19.4%), coronary artery disease (15.0%), myocardial infarction (6.4%), dyslipidemia (42.4%), and chronic kidney disease (26.4%). The mean CHADS2 score was 2.09±1.35: 0 in 11.8% of patients, 1 in 27.1%, and 2 in 29.1%. Warfarin was prescribed in only 48.5% of patients, whereas anti-platelet drugs, mainly aspirin, were prescribed for more than 30% of the patients. CONCLUSIONS The Fushimi AF Registry provides a unique snapshot of current AF management in an urban community in Japan.

Long-Term Outcomes of Coronary-Artery Bypass Graft Surgery Versus Percutaneous Coronary Intervention for Multivessel Coronary Artery Disease in the Bare-Metal Stent Era

Background— Observational registries comparing coronary artery bypass graft (CABG) surgery and percutaneous coronary intervention (PCI) have reported long-term survival results that are discordant with those of randomized trials. Methods and Results— We conducted a multicenter study in Japan enrolling consecutive patients undergoing first CABG or PCI between January 2000 and December 2002. Among 9877 patients enrolled, 5420 (PCI: 3712, CABG: 1708) had multivessel disease without left main involvement. Because age is an important determinant when choosing revascularization strategies, survival analysis was stratified by either age ≥75 or <75 years. Analyses were also performed in other relevant subgroups. Median follow-up interval was 1284 days with 95% follow-up rate at 2 years. At 3 years, unadjusted survival rates were 91.7% and 89.6% in the CABG and PCI groups, respectively (log rank P=0.26). After adjustment for baseline characteristics, survival outcome tended to be better after CABG (hazard ratio for death after PCI versus CABG [HR], 95% confidence interval [CI]: 1.23 [0.99-1.53], P=0.06). Adjusted survival outcomes also tended to be better for CABG among elderly patients (HR [95%CI]: 1.37 [0.98-1.92] P=0.07), but not among nonelderly patients (HR [95% CI]: 1.09 [0.82-1.46], P=0.55). Unadjusted and adjusted survival outcome for CABG and PCI were not significantly different in any subgroups when elderly patients were excluded from analysis. Conclusions— In the CREDO-Kyoto registry, survival outcomes among patients <75 years of age were similar after PCI and CABG, a result that is consistent with those of randomized trials.

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.

Incidence of Stroke or Systemic Embolism in Paroxysmal Versus Sustained Atrial Fibrillation The Fushimi Atrial Fibrillation Registry

Background and Purpose— There is controversy on the relationship of the type of atrial fibrillation (AF) to stroke. Although several studies show that patients with paroxysmal AF (PAF) have a stroke risk similar to those with persistent or permanent AF, recent studies suggest that PAF is associated with a lower rate of stroke. Limited data on stroke risk associated with PAF are evident in Asian populations. Methods— The Registry Study of Atrial Fibrillation Patients in Fushimi-ku (Fushimi AF Registry) is a community-based survey of patients with AF in Fushimi-ku, Kyoto, Japan. Patients were categorized into 2 types of AF: PAF or sustained (persistent or permanent) AF. We compared clinical events between PAF (n=1588) and sustained AF (n=1716). Results— Patients with PAF were younger, had less comorbidities, and received oral anticoagulants (OAC) less commonly. A lower risk of stroke/systemic embolism during follow-up period in the patients with PAF was consistently observed (non-OAC users: hazard ratio, 0.45; 95% confidence intervals, 0.27–0.75; P<0.01 and OAC users: hazard ratio, 0.59; 95% confidence interval, 0.35–0.93; P=0.03). The composite end point of stroke/systemic embolism/all-cause mortality was also lower in PAF, whether among OAC users (hazard ratio, 0.77; 95% confidence interval, 0.59–0.99; P=0.046) or non-OAC users (hazard ratio, 0.59; 95% confidence interval, 0.46–0.75; P<0.01). On multivariate analysis, PAF was an independent predictor of lower stroke/systemic embolism risk. Conclusions— In this large cohort of Japanese patients with AF, PAF was independently associated with lower incidence of stroke/systemic embolism than sustained AF. This may aid decision making for anticoagulation, especially in those patients with AF with few stroke risk factors. Clinical Trial Registration— URL: http://www.umin.ac.jp/ctr/index.htm. Unique identifier: UMIN000005834.

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.

Sirolimus-Eluting Stent Versus Balloon Angioplasty for Sirolimus-Eluting Stent Restenosis: Insights From the j-Cypher Registry

Background— Optimal treatment strategies for restenosis of sirolimus-eluting stents (SES) have not been adequately addressed yet. Methods and Results— During the 3-year follow-up of 12 824 patients enrolled in the j-Cypher registry, 1456 lesions in 1298 patients underwent target-lesion revascularization (TLR). Excluding 362 lesions undergoing TLR for stent thrombosis or TLR using treatment modalities other than SES or balloon angioplasty (BA), 1094 lesions with SES-associated restenosis in 990 patients treated with either SES (537 lesions) or BA (557 lesions) constituted the study population for the analysis of recurrent TLR and stent thrombosis after the first TLR. Excluding 24 patients with both SES- and BA-treated lesions, 966 patients constituted the analysis set for the mortality outcome. Cumulative incidence of recurrent TLR in the SES-treated restenosis lesions was significantly lower than that in the BA-treated restenosis lesions (23.8% versus 37.7% at 2 years after the first TLR; P<0.0001). Among 33 baseline variables evaluated, only hemodialysis was identified to be the independent risk factor for recurrent TLR by a multivariable logistic regression analysis. After adjusting for confounders, repeated SES implantation was associated with a strong treatment effect in preventing recurrent TLR over BA (odds ratio, 0.44; 95% confidence interval, 0.32 to 0.61; P<0.0001). The 2-year mortality and stent thrombosis rates between the SES- and the BA-treated groups were 10.4% versus 10.8% (P=0.4) and 0.6% versus 0.6%, respectively. Conclusions— Repeated implantation of SES for SES-associated restenosis is more effective in preventing recurrent TLR than treatment with BA, without evidence of safety concerns.