Low-Density Lipoprotein Cholesterol Levels on Statins and Cardiovascular Event Risk in Stable Coronary Artery Disease　- An Observation From the REAL-CAD Study.

BACKGROUND: The relationship between very low on-treatment low-density lipoprotein cholesterol (LDL-C) level and cardiovascular event risk is still unclear in patients receiving the same doses of statins.Methods and Results: From the REAL-CAD study comparing high-dose (4 mg/day) with low-dose (1 mg/day) pitavastatin therapy in patients with stable coronary artery disease, 11,105 patients with acceptable statin adherence were divided into 3 groups according to the on-treatment LDL-C level at 6 months (<70 mg/dL, 70-100 mg/dL, and ≥100 mg/dL). The primary outcome measure was a composite of cardiovascular death, non-fatal myocardial infarction, non-fatal ischemic stroke, or unstable angina requiring emergent admission. The adjusted risks of the LDL-C <70 mg/dL group relative to the LDL-C 70-100 mg/dL group (reference) was not significantly different for the primary outcome measure in both 1 mg/day and 4 mg/day strata (HR 0.84, 95% CI 0.58-1.18, P=0.32, and HR 1.25, 95% CI 0.88-1.79, P=0.22). The adjusted risk of the LDL-C ≥100 mg/dL group relative to the reference group was not significant for the primary outcome measure in the 1 mg/day stratum (HR 0.82, 95% CI 0.60-1.11, P=0.21), whereas it was highly significant in the 4 mg/day stratum (HR 3.32, 95% CI 2.08-5.17, P<0.001). CONCLUSIONS: A very low on-treatment LDL-C level (<70 mg/dL) was not associated with lower cardiovascular event risk compared with moderately low on-treatment LDL-C level (70-100 mg/dL) in patients receiving the same doses of statins.

Atrial fibrillation in patients with severe aortic stenosis.

BACKGROUND: There has been no previous report evaluating the long impact of atrial fibrillation (AF) on the clinical outcomes stratified by the initial management [conservative or aortic valve replacement (AVR)] strategies of severe aortic stenosis (AS). METHODS: We analyzed 3815 patients with severe AS enrolled in the CURRENT AS registry. Patients with AF were defined as those having a history of AF when severe AS was found on the index echocardiography. The primary outcome measure was a composite of aortic valve-related death or hospitalization for heart failure. RESULTS: The cumulative 5-year incidence of the primary outcome measure was significantly higher in patients with AF than in those without AF (44.2 % versus 33.2 %, HR 1.54, 95 % CI 1.35-1.76). After adjusting for confounders, the risk of AF relative to no AF remained significant (HR 1.34, 95 % CI 1.16-1.56). The magnitude of excess adjusted risk of AF for the primary outcome measure was greater in the initial AVR stratum (N = 1197, HR 1.95, 95 % CI 1.36-2.78) than in the conservative stratum (N = 2618, HR 1.26, 95 % CI 1.08-1.47) with a significant interaction (p = 0.04). In patients with AF, there was a significant excess adjusted risk of paroxysmal AF (N = 254) relative to chronic AF (N = 528) for the primary outcome measure (HR 1.34, 95 % CI 1.01-1.78). CONCLUSIONS: In patients with severe AS, concomitant AF was independently associated with worse clinical outcomes regardless of the initial management strategies. In those patients with conservative strategy, paroxysmal AF is stronger risk factor than chronic AF.

Thrombotic Risk Stratification and Intensive Statin Therapy for Secondary Prevention of Coronary Artery Disease　- Insights From the REAL-CAD Study.

BACKGROUND: It is unknown whether beneficial effects of higher-dose statins on cardiovascular events are different according to the thrombotic risk in patients with chronic coronary syndrome (CCS).Methods and Results: The Randomized Evaluation of Aggressive or Moderate Lipid-Lowering Therapy with Pitavastatin in Coronary Artery Disease (REAL-CAD) study is a randomized trial comparing 4 mg and 1 mg pitavastatin in patients with CCS. This study categorized 12,413 patients into 3 strata according to the CREDO-Kyoto thrombotic risk score: low-risk (N=9,434; 4 mg: N=4,742, and 1 mg: N=4,692), intermediate-risk (N=2,415; 4 mg: N=1,188, and 1 mg: N=1,227); and high-risk (N=564; 4 mg: N=269, and 1 mg: N=295). The primary endpoint was a composite of cardiovascular death, non-fatal myocardial infarction, non-fatal ischemic stroke, or unstable angina. Cumulative 4-year incidence of the primary endpoint was significantly higher in the high-risk stratum than in the intermediate- and low-risk strata (11.0%, 6.3%, and 4.5%, P<0.0001). In the low-risk stratum, the cumulative 4-year incidence of the primary endpoint was significantly lower in the 4 mg than in the 1 mg group (4.0% and 4.9%, P=0.02), whereas in the intermediate- and high-risk strata, it was numerically lower in the 4 mg than in the 1 mg group. There was no significant treatment-by-subgroup interaction for the primary endpoint (P-interaction=0.77). CONCLUSIONS: High-dose pitavastatin therapy compared with low-dose pitavastatin therapy was associated with a trend toward lowering the risk for cardiovascular events irrespective of the thrombotic risk in patients with CCS.

Efficacy of the Wolverine cutting balloon on a circumferential calcified coronary lesion: Bench test using a three-dimensional printer and computer simulation with the finite element method.

Heavy calcification is one of the factors that hinder the success of coronary angioplasty, and a cutting balloon is used for such lesions. This study aimed to explore the optimal method of dilation of highly calcified lesions using a cutting balloon. Calcification models were developed from patient computed tomography and intravascular ultrasound data, and were constructed using three-dimensional printers. The lesions were dilated using a Wolverine™ cutting balloon and NC Emerge™ noncompliant balloon catheter, and the success rate of dilation and maximum dilation pressure were compared. The maximum first principal stresses in calcified lesions were also evaluated by computer simulation using the finite element method. In the bench test, the dilation success rate of the Wolverine™ cutting balloon was higher and the maximum dilation pressure required was lower (p < 0.01 in all analyses), compared with that of the NC Emerge™ balloon catheter. Finite element analysis showed that the cutting blade increased the maximum first principal stresses in calcified lesions, thus allowing for successful dilation at low pressures. The highest stress was obtained when the cutting blade was positioned at the thinnest part of the calcification. The cutting balloon allows for efficient calcification expansion by concentrating the stresses in the blade. When a cutting balloon is used, if the calcified lesion cannot be expanded in a single dilation, dilation success may be achieved after the balloon is rotated and the position of the blade is changed.

Wolverine cutting balloon in the treatment of stent underexpansion in heavy coronary calcification: bench test using a three-dimensional printer and computer simulation with the finite-element method.

Heavy coronary calcification hinders successful stent implantation, and cutting balloons can be used for post-dilation after stent deployment. However, evidence regarding its use is limited to case reports. Therefore, this study aimed to investigate in-stent dilation in circumferential coronary calcifications using Wolverine cutting balloons, compared with conventional non-compliance (NC) balloons. Circumferential coronary calcification models were designed based on the patient's intravascular ultrasound images. Three-dimensional printed models were subjected to bench tests and software analysis was performed using the finite-element method (FEM). As a result, the bench test showed that higher balloon pressure was needed to dilate the models with stent implantation, either using Wolverine (17.1 ± 2.7 atm) or NC Emerge (18.9 ± 1.8 atm), while lower pressure was needed in models without stents using Wolverine [11.7 ± 2.9 atm, analysis of variance (ANOVA) p < 0.001]. Furthermore, models without stents were all successfully cracked by Wolverine at the first dilation, while models with stent implantation needed more dilations (ANOVA p = 0.0132). The FEM showed similar results that the first principal stress was the highest in Wolverine-dilated models without stents. In conclusion, implanted stents significantly increase the difficulty of balloon dilation and adequate pretreatment is critical for successful coronary stenting.

Overview of the 84th Annual Scientific Meeting of the Japanese Circulation Society　- Change Practice!

Due to the COVID-19 pandemic, the 84thAnnual Meeting of the Japanese Circulation Society (JCS) was held in a web-based format for the first time in its history as "The Week for JCS 2020" from Monday, July 27 to Sunday, August 2, 2020. All sessions, including general abstracts, were streamed live or on-demand. The main theme of the meeting was "Change Practice!" and the aim was to organize the latest findings in the field of cardiovascular medicine and discuss how to change practice. The total number of registered attendees was over 16,800, far exceeding our expectations, and many of the sessions were viewed by far more people than at conventional face-to-face scientific meetings. At this conference, the power of online information dissemination was fully demonstrated, and the evolution of online academic meetings will be a direction that cannot be reversed in the future. The meeting was completed with great success, and we express our heartfelt gratitude to all affiliates for their enormous amount of work, cooperation, and support.

Clinical outcome after surgical aortic valve replacement in low-risk Japanese patients with severe aortic stenosis.

Two randomized control trials demonstrated that transcatheter aortic valve implantation was associated with 1-2 year clinical outcomes comparable or even superior to surgical aortic valve replacement (SAVR) in low surgical risk patients with severe aortic stenosis (AS). However, no previous study has reported the clinical outcomes after SAVR in Japanese patients with low surgical risk. From 3815 consecutive patients enrolled in the CURRENT AS registry, we retrieved 220 patients who underwent SAVR in reference to the inclusion and exclusion criteria of the PARTNER 3 trial. Age and surgical risk score in the current study population were comparable to those in the PARTNER 3 trial (Age: 75 years versus 74 years, and STS-PROM score: 2.3 versus 1.9). The cumulative incidence of a composite all-cause death or stroke was comparable between the current study population and the SAVR patients in the PARTNER 3 trial both at 30-day (2.3% versus 3.3%), and at 1-year (4.1% versus 4.9%). The clinical outcomes of SAVR in low surgical risk patients with severe AS selected from a real world Japanese registry according to the inclusion and exclusion criteria of the PARTNER 3 trial was favorable and numerically comparable to those of SAVR patients in the PARTNER 3 trial.

Stent-Related Adverse Events as Related to Dual Antiplatelet Therapy in First- vs Second-Generation Drug-Eluting Stents.

Background: There are limited data on the long-term stent-related adverse events as related to the duration of dual antiplatelet therapy (DAPT) in second-generation (G2) drug-eluting stents (DES) compared with first-generation (G1) DES. Objectives: This study sought to compare the long-term stent-related outcomes of G2-DES with those of G1-DES. Methods: The study group consisted of 15,009 patients who underwent their first coronary revascularization with DES from the CREDO-Kyoto PCI/CABG (Coronary Revascularization Demonstrating Outcome Study in Kyoto Percutaneous Coronary Intervention/Coronary Artery Bypass Grafting) Registry Cohort-2 (first-generation drug-eluting stent [G1-DES] period; n = 5,382) and Cohort-3 (second-generation drug eluting stent [G2-DES] period; n = 9,627). The primary outcome measures were definite stent thrombosis (ST) and target vessel revascularization (TVR). Results: The cumulative 5-year incidences of definite ST and TVR were significantly lower in the G2-DES group than in the G1-DES group (0.7% vs 1.4%; P < 0.001; and 16.2% vs 22.1%; P < 0.001, respectively). The lower adjusted risk of G2-DES relative to G1-DES for definite ST and TVR remained significant (HR: 0.53; 95% CI: 0.37-0.76; P < 0.001; and HR: 0.74; 95% CI: 0.68-0.81; P < 0.001, respectively). In the landmark analysis that was based on the DAPT status at 1 year, the lower adjusted risk of on-DAPT status relative to off-DAPT was significant for definite ST beyond 1 year in the G1-DES stratum (HR: 0.42; 95% CI: 0.24-0.76; P = 0.004) but not in the G2-DES stratum (HR: 0.66; 95% CI: 0.26-1.68; P = 0.38) (P interaction = 0.14). Conclusions: G2-DES compared with G1-DES were associated with a significantly lower risk for stent-related adverse events, including definite ST and TVR. DAPT beyond 1 year was associated with a significantly lower risk for very late ST of G1-DES but not for that of G2-DES.

Application of the Modified High Bleeding Risk Criteria for Japanese Patients in an All-Comers Registry of Percutaneous Coronary Intervention　- From the CREDO-Kyoto Registry Cohort-3.

BACKGROUND: The prevalence of and expected bleeding event rate in patients with the Japanese version of high bleeding risk (J-HBR) criteria are currently unknown in real-world percutaneous coronary intervention (PCI) practice.Methods and Results:We applied the J-HBR criteria in the multicenter CREDO-Kyoto registry cohort-3 that enrolled 13,258 consecutive patients who underwent first PCI. The J-HBR criteria included Japanese-specific major criteria such as heart failure, low body weight, peripheral artery disease and frailty in addition to the Academic Research Consortium (ARC)-HBR criteria. There were 8,496 patients with J-HBR, and 4,762 patients without J-HBR. The J-HBR criteria identified a greater proportion of patients with HBR than did ARC-HBR (64% and 48%, respectively). Cumulative incidence of the Bleeding Academic Research Consortium (BARC) type 3 or 5 bleeding was significantly higher in the J-HBR group than in the no-HBR group (14.0% vs. 4.1% at 1 year; 23.1% vs. 8.4% at 5 years, P<0.0001). Cumulative 5-year incidence of BARC 3/5 bleeding was 25.1% in patients with ARC-HBR, and 23.1% in patients with J-HBR. Cumulative incidence of myocardial infarction or ischemic stroke was also significantly higher in the J-HBR group than in the no-HBR group (6.9% vs. 3.6% at 1 year; 13.2% vs. 7.1% at 5 years, P<0.0001). CONCLUSIONS: The J-HBR criteria successfully identified those patients with very high bleeding risk after PCI, who represented 64% of patients in this all-comers registry.

Periprocedural Stroke After Coronary Revascularization (from the CREDO-Kyoto PCI/CABG Registry Cohort-3).

There is a scarcity of data on incidence, risk factors, especially clinical severity, and long-term prognostic impact of periprocedural stroke after coronary revascularization in contemporary real-world practice. Among 14,867 consecutive patients undergoing first coronary revascularization between January 2011 and December 2013 (percutaneous coronary intervention [PCI]: N = 13258, and coronary artery bypass grafting [CABG]: N = 1609) in the Coronary Revascularization Demonstrating Outcome Study in Kyoto PCI/CABG registry Cohort-3, we evaluated the details on periprocedural stroke. Periprocedural stroke was defined as stroke within 30 days after the index procedure. Incidence of periprocedural stroke was 0.96% after PCI and 2.13% after CABG (log-rank p <0.001). Proportions of major stroke defined by modified Rankin Scale ≥2 at hospital discharge were 68% after PCI, and 77% after CABG. Independent risk factors of periprocedural stroke were acute coronary syndrome (ACS), carotid artery disease, advanced age, heart failure, and end-stage renal disease after PCI, whereas they were ACS, carotid artery disease, atrial fibrillation, chronic obstructive pulmonary disease, malignancy, and frailty after CABG. There was excess long-term mortality risk of patients with periprocedural stroke relative to those without after both PCI and CABG (hazard ratio 1.71 [1.25 to 2.33], and hazard ratio 4.55 [2.79 to 7.43]). In conclusion, incidence of periprocedural stroke was not negligible not only after CABG, but also after PCI in contemporary real-world practice. Majority of patients with periprocedural stroke had at least mild disability at hospital discharge. ACS and carotid artery disease were independent strong risk factors of periprocedural stroke after both PCI and CABG. Periprocedural stroke was associated with significant long-term mortality risk after both PCI and CABG.

Long-Term Impact of Diabetes Mellitus on Initially Conservatively Managed Patients With Severe Aortic Stenosis.

BACKGROUND: Although diabetes mellitus (DM) is a common comorbidity of aortic stenosis (AS), clinical evidence about the long-term effect of DM on patients with AS is insufficient.Methods and Results:Data were acquired from CURRENT AS, a large Japanese multicenter registry that enrolled 3,815 patients with severe AS. Patients without initial valve replacement were defined as the conservative group; among them, 621 (23.4%) had DM, whereas 1997 did not. The DM group was further divided into 2 groups according to insulin treatment (insulin-treated DM, n=130; non-insulin treated DM, n=491). The primary outcome was a composite of aortic valve (AV)-related death and heart failure (HF) hospitalization. Secondary outcomes were AV-related death, HF hospitalization, all-cause death, cardiovascular death, sudden death, and surgical or transcatheter AV replacement during follow up. As a result, DM was associated with higher risk for the primary outcome (52.8% vs. 42.9%, P<0.001), with a statistically significant adjusted hazard ratio (HR 1.33, 95% confidence interval: 1.14-1.56, P<0.001). All secondary outcomes were not significantly different between DM and non-DM patients after adjusting for confounding factors, except for HF hospitalization. Insulin use was not associated with higher incidence of primary or secondary outcome. CONCLUSIONS: In initially conservatively managed patients with AS, DM was independently associated with higher risk for a composite of AV-related death or HF hospitalization; however, insulin use was not associated with poor outcomes.

Effects of Body Weight on Bleeding and Ischemic Events in Patients Undergoing Percutaneous Coronary Intervention　- From the CREDO-Kyoto Registry Cohort-2.

BACKGROUND: The effect of body weight (BW) on bleeding and ischemic events has not been adequately evaluated in real-world percutaneous coronary intervention (PCI) practice.Methods and Results:12,690 consecutive patients undergoing first PCI in the CREDO-Kyoto registry cohort-2 were divided into 3 groups according to tertiles of BW stratified by sex (male; Tertile 1 [<60.0 kg], 2 [60.0-68.0 kg], and 3 [>68.0 kg], and female; Tertile 1 [<47.9 kg], 2 [47.9-55.8 kg], and 3 [>55.8 kg]). Cumulative 5-year incidences of the primary bleeding (GUSTO moderate/severe) and ischemic (myocardial infarction/ischemic stroke) endpoints increased incrementally with decrease in BW in both strata (male Tertiles 1, 2, and 3: 13.7%, 10.3%, and 8.0%, P<0.001, and 13.9%, 11.3%, and 10.2%, P<0.001; female Tertiles 1, 2, and 3: 17.9%, 12.9%, and 10.1%, P<0.001, and 17.9%, 12.9%, and 10.1%, P<0.001). Compared with Tertile 3, the adjusted risks of Tertile 1 for the primary bleeding and ischemic endpoints remained significant in the female stratum (hazard ratio (HR): 1.45, 95% confidence interval (CI): 1.14-1.87, P=0.003, and HR:1.49, 95% CI:1.13-1.95, P=0.004), but not in the male stratum (HR:1.10, 95% CI:0.92-1.32, P=0.31, and HR:1.06, 95% CI:0.90-1.27, P=0.47). CONCLUSIONS: Cumulative incidences of bleeding and ischemic events increased incrementally as BW decreased in both men and women. The adjusted risks of underweight relative to overweight for bleeding and ischemic events were significant only in women.

Elective Non-Cardiac Surgery in Patients With Severe Aortic Stenosis　- Observations From the CURRENT AS Registry.

BACKGROUND: Patients with severe aortic stenosis (AS) might be at high risk for adverse cardiovascular events at the time of non-cardiac surgery.Methods and Results:The current study population included 348 patients who underwent elective non-cardiac surgery under general or spinal anesthesia during the follow up of 3,815 patients in the CURRENT AS (Contemporary outcomes after sURgery and medical tREatmeNT in patients with severe Aortic Stenosis) registry. There were 187 patients with untreated severe AS at time of surgery (untreated severe AS group) and 161 patients who had undergone aortic valve replacement (AVR) before surgery (prior AVR group), including 23 patients with prophylactic AVR. The primary outcome measure was 30-day mortality after non-cardiac surgery. At 30 days after non-cardiac surgery, 8 patients (4.3%) died in the untreated severe AS group, while no patients died in the prior AVR group (P=0.008). The causes of death were cardiovascular in 6 out of 8 patients. Mortality at 30 days was higher in untreated severe AS patients with AS-related symptoms before surgery than in those without AS-related symptoms (7.2% vs. 3.1%). Higher surgical risk estimates of the non-cardiac surgery incrementally increased the risk of 30-day mortality in patients with untreated severe AS, though the difference was not statistically significant (low-risk: 0%, intermediate-risk: 4.3%, and high-risk: 6.6 %, P=0.46). CONCLUSIONS: Symptomatic and asymptomatic severe AS might be associated with higher risk of 30-day mortality if untreated before elective intermediate- and high-risk non-cardiac surgery, while no patient with prior AVR died after elective non-cardiac surgery.

Preprocedural Planning Using a Three-Dimensional Printed Model for Percutaneous Coronary Intervention in an Anomalous Coronary Artery.

BACKGROUND Three-dimensional (3D) printed models have been recently introduced for diagnosis and preprocedural planning for percutaneous interventions or surgery in cardiovascular disease. CASE REPORT We treated a 71-year-old woman with angina. Although we performed coronary angiography, we could not engage the catheters for the left coronary artery (LCA). Then, we withdrew the catheter and examined her anatomy using coronary computed tomographic angiography (CCTA). The CCTA revealed that the LCA originated from the noncoronary cusp (NCC). Because anomalous LCA originating from the NCC is a rare congenital anomaly, percutaneous coronary intervention was considered difficult. We decided to use a 3D-printed model, which enabled us to clearly see the anatomy and simulation before the actual procedure, which went smoothly according to the preprocedural planning using the 3D printed model. 3D printed modeling is feasible for use in reproducing coronary artery anatomy and enhancing understanding of coronary abnormalities. CONCLUSIONS Use of 3D-printed models is a useful new option that can help visualize the anatomy and perform preprocedural planning for complex cases.

Transradial vs. Transfemoral Percutaneous Coronary Intervention in Patients With or Without High Bleeding Risk Criteria.

BACKGROUND: The transradial approach is reportedly associated with reduced bleeding complications and mortality after percutaneous coronary intervention (PCI). It is unknown whether the clinical benefits of transradial vs. transfemoral PCI differ between high bleeding risk (HBR) and non-HBR patients.Methods and Results:After excluding patients with acute myocardial infarction, dialysis, and a transbrachial approach from the 13,087 patients undergoing first PCI in the CREDO-Kyoto Registry Cohort-2, 6,828 patients were eligible for this study. Patients were divided into 2 groups according to bleeding risk based on Academic Research Consortium HBR criteria, and then divided into a further 2 groups according to access site, radial or femoral: HBR-radial, n=1,054 (38.3%); HBR-femoral, n=1,699 (61.7%); non-HBR-radial, n=1,682 (41.3%); and non-HBR-femoral, n=2,393 (58.7%). In the HBR group, the 30-day incidence and adjusted risk for major bleeding (1.9% vs. 4.7% [P<0.001]; adjusted hazard ratio [aHR] 0.44, 95% confidence interval [CI] 0.26-0.71 [P<0.001]) and all-cause death (0.3% vs. 0.9% [P=0.04]; aHR 0.30, 95% CI 0.07-0.93 [P=0.04]) were significantly lower in the radial than femoral group. There were no significant differences in the 30-day incidence and adjusted risk for major bleeding (0.5% vs. 1.0% [P=0.09]; aHR 0.68, 95% CI 0.30-1.45 [P=0.33]) or all-cause death (0.1% vs. 0.1% [P=0.96]; aHR 1.51, 95% CI 0.19-9.54 [P=0.67]) between the radial and femoral approaches in the non-HBR group. CONCLUSIONS: Compared with transfemoral PCI, transradial PCI was associated with lower risk for 30-day major bleeding and mortality in HBR but not non-HBR patients.

Transcatheter Aortic Valve Implantation vs. Surgical Aortic Valve Replacement for Severe Aortic Stenosis in Real-World Clinical Practice.

BACKGROUND: There are no data comparing transcatheter aortic valve implantation (TAVI) with surgical aortic valve replacement (SAVR) outcomes in real clinical practice in Japan. METHODS AND RESULTS: We combined 2 independent registries, the K-TAVI Registry (a 6-center prospective registry of consecutive patients who underwent TAVI) and the CURRENT AS Registry (a large, 27-center registry of 3,815 consecutive patients with severe aortic stenosis [AS]). In the K-TAVI Registry, 338 patients underwent TAVI with SAPIEN XT balloon-expandable valves from October 2013 to January 2016, whereas in the CURRENT AS Registry 237 patients with severe AS underwent SAVR from January 2003 to December 2011. Propensity score matching was conducted, with final cohort comprising 306 patients. The cumulative 2-year incidence of all-cause death and heart failure (HF) hospitalization did not differ significantly between the TAVI and SAVR groups (13.7% vs. 12.4% [P=0.81] and 7.9% vs 3.9% [P=0.13], respectively). After adjusting for residual confounders, there were no significant differences between the TAVI and SAVR groups in the risk for all-cause death (hazard ratio [HR] 0.74; 95% confidence interval [CI] 0.35-1.58; P=0.43) or HF hospitalization (HR 1.27; 95% CI 0.40-4.59; P=0.69). CONCLUSIONS: These findings from 2 independent Japanese registries suggest that the 2-year risk of all-cause mortality and HF does not differ significantly between TAVI and SAVR groups in real-world practice in Japan.

Prediction of post-intervention fractional flow reserve in diffuse or sequential coronary stenosis considering the residual trans-stent pressure gradient: Post-intervention FFR in diffuse/sequential lesions.

AIMS: Prediction of post-intervention fractional flow reserve (FFR) in a diffuse or sequential coronary lesion is difficult due to complex haemodynamic interactions between individual stenoses. Furthermore, the existence of a residual intra-stent pressure gradient makes the prediction difficult. We developed an equation predicting the post-intervention FFR in a diffuse/sequential lesion by considering intra-stent FFR gradient. The present study aims to validate the equation in an in vitro model and in clinical data. METHODS AND RESULTS: In the in vitro experiment, three sequential coronary stenoses were made with a collateral flow. The correlation coefficient of the predicted FFR and the actual post-intervention FFR was 0.99, and the absolute difference was 0.008±0.006 (n=50). In the clinical data analysis, the correlation coefficient was 0.41, and the absolute difference was 0.06±0.05 (n=67). We applied a fixed value of intra-stent FFR gradient and a collateral flow index so that the equation can be used in clinical practice. The correlation coefficient became 0.28 and the absolute difference became 0.06±0.06. CONCLUSIONS: In clinical practice, prediction of post-intervention FFR in a diffuse/sequential lesion is difficult even when residual intra-stent pressure gradient is considered.

Evaluation of a portable assembly catheter simulator using a 3D-printed heart model for percutaneous transvenous mitral commissurotomy in developing countries: Catheter simulator for PTMC.

AIMS: We developed a catheter simulator for percutaneous transvenous mitral commissurotomy (PTMC) based on the data from a patient with mitral valve stenosis. The simulator has the following characteristics: 1) the simulator is portable and easy to assemble and disassemble, 2) the cardiac portion is created using a 3D-printer, based on patient computed tomography data, 3) the simulator uses a foot-operated water pump to create pulsatile flow, and 4) the fossa ovalis in the atrial septum of the heart model is made of a thin polyurethane membrane and is interchangeable. We aimed to assess the effectiveness of this novel simulator for training in PTMC using the Inoue balloon in developing countries. METHODS AND RESULTS: We used this simulator for training in the National Institute of Cardiovascular Diseases in Bangladesh (13 physicians), and in Kenyatta National Hospital in Kenya (11 physicians). The effectiveness of training was evaluated by questionnaire and the procedure time in simulation. The questionnaire obtained from the trainees showed that the model scored 4.7±0.5 for realism, utility of pulsatile flow scored 4.7±0.5, simulator utility scored 4.9±0.3, and the effect of training on PTMC performance scored 4.9±0.5. The procedure time in simulation was shortened from 30.0±12.6 min (first time), to 23.4±11.9 min (second time) and to 20.4 ± 11.1 min (third time) (p<0.01). CONCLUSIONS: The novel portable assembly catheter simulator using a 3D-printed heart model for PTMC received positive comments and improved the skills of trainees.

A risk prediction model in asymptomatic patients with severe aortic stenosis: CURRENT-AS risk score.

AIMS: Early aortic valve replacement (AVR) might be beneficial in selected high-risk asymptomatic patients with severe aortic stenosis (AS), considering their poor prognosis when managed conservatively. This study aimed to develop and validate a clinical scoring system to predict AS-related events within 1 year after diagnosis in asymptomatic severe AS patients. METHODS AND RESULTS: We analysed 1274 asymptomatic severe AS patients derived from a retrospective multicentre registry enrolling consecutive patients with severe AS in Japan (CURRENT AS registry), who were managed conservatively and completed 1-year follow-up without AVR. From a randomly assigned derivation set (N = 849), we developed CURRENT AS risk score for the AS-related event (a composite of AS-related death and heart failure hospitalization) within 1 year using a multivariable logistic regression model. The risk score comprised independent risk predictors including left ventricular ejection fraction <60%, haemoglobin ≤11.0 g/dL, chronic lung disease (2 points), diabetes mellitus, haemodialysis, and any concomitant valve disease (1 point). The predictive accuracy of the model was good with the area under the curve of 0.79 and 0.77 in the derivation and validation sets (N = 425). In the validation set, the 1-year incidence of AS-related events was much higher in patients with score ≥2 than in patients with score ≤1 (Score 0: 2.2%, Score 1: 1.9%, Score 2: 13.4%, Score 3: 14.3%, and Score ≥4: 22.7%, P < 0.001). CONCLUSION: The CURRENT-AS risk score integrating clinical and echocardiographic factors well-predicted the risk of AS-related events at 1 year in asymptomatic patients with severe AS and was validated internally.

On-site evaluation of CT-based fractional flow reserve using simple boundary conditions for computational fluid dynamics.

Fractional flow reserve (FFR) is an established method for diagnosing physiological coronary artery stenosis. A method for computing FFR using coronary computed tomography (CT) images was recently developed. However, its calculation requires off-site supercomputer analysis. Here, we report the preliminary result of a method using simple estimation of boundary conditions. The lumen boundaries of the coronary arteries were semi-automatically delineated using full width at half maximum of CT number profiles. The computational fluid dynamics (CFD) of the blood flow was performed using the boundary conditions of a fixed pressure at the coronary ostium and flow rates at each outlet. The total inflow at the coronary ostium was estimated based on the uniform wall shear stress hypothesis and corrected using a hyperemic multiplier to gain a hyperemic flow rate. The flow distribution from a parent vessel to the downstream daughter vessels was determined according to Murray's law. FFR estimated by CFD was calculated as FFRCFD = Pd/Pa. We collected patients who underwent coronary CT and coronary angiography followed by invasively measured FFR and compared FFRCFD with FFR. Sensitivity, specificity, and correlations were assessed. A total of 48 patients and 72 arteries were assessed. The correlation coefficient of FFRCFD with FFR was 0.56. The cut-off value was ≤ 0.80, sensitivity was 59.1%, and specificity was 94.0%. CFD-based FFR using simple boundary conditions for on-site clinical computation provided FFRCFD values that were moderately correlated with invasively measured FFR.