Impact of the clinical frailty scale on long-term outcomes after transcatheter aortic valve implantation.

BACKGROUND: The semiquantitative Clinical Frailty Scale (CFS) is reportedly a useful marker for predicting short- and mid-term mortality after transcatheter aortic valve implantation (TAVI). We assessed the long-term prognostic impact of CFS in patients with severe aortic stenosis undergoing TAVI. METHODS: We prospectively assessed patients undergoing TAVI in Kokura Memorial Hospital using a 9-level CFS and enrolled 1594 patients after excluding patients with CFS 8-9. The patients were divided into the low (CFS level, 1-3; N = 842), intermediate (4; N = 469), and high (5-7; N = 283) groups according to their CFS levels. RESULTS: In the low, intermediate, and high groups, 3-year all-cause mortality rates were 17.4%, 29.4%, and 41.7% (P < .001) and composite rates of cardiovascular mortality and heart failure hospitalization were 12.1%, 19.1%, and 23.9% (P < .001), respectively. Multivariable analysis showed that higher frailty was independently associated with all-cause mortality (intermediate group: adjusted hazard ratio [HR], 1.63, 95% confidence interval [CI], 1.24-2.15, P < .001; high group: adjusted HR, 2.18, 95% CI, 1.59-2.99, P < .001) and composite of cardiovascular mortality and heart failure hospitalization (intermediate group: adjusted HR, 1.47, 95% CI, 1.04-2.08, P = .030; high group: adjusted HR, 1.66, 95% CI, 1.09-2.51, P = .018) and this result was consistent, irrespective of stratification based on age, sex, body mass index, left ventricular ejection fraction, Society of Thoracic Surgeons score, and New York Heart Association functional class without significant interaction. CONCLUSIONS: The simple CFS tool predicts the long-term adverse outcomes post-TAVI.

Prognostic Value of the Severity of Clinical Congestion in Patients Hospitalized for Decompensated Heart Failure: Findings From the Japanese KCHF Registry.

BACKGROUND: Congestion is a leading cause of hospitalization and a major therapeutic target in patients with heart failure (HF). Clinical practice in Japan is characterized by a long hospital stay, which facilitates more extensive decongestion during hospitalization. We herein examined the time course and prognostic impact of clinical congestion in a large contemporary Japanese cohort of HF. METHODS AND RESULTS: Peripheral edema, jugular venous pressure, and orthopnea were graded on a standardized 4-point scale (0-3) in 3787 hospitalized patients in a Japanese cohort of HF. Composite Congestion Scores (CCS) on admission and at discharge were calculated by summing individual scores. The primary outcome was a composite of all-cause death or HF hospitalization. The median admission CCS was 4 (interquartile range, 3-6). Overall, 255 patients died during the median hospitalization length of 16 days, and 1395 died or were hospitalized for HF over a median postdischarge follow-up of 396 days. The cumulative 1-year incidence of the primary outcome increased at higher tertiles of congestion on admission (32.5%, 39.3%, and 41.0% in the mild [CCS ≤3], moderate [CCS = 4 or 5], and severe [CCS ≥6] congestion groups, respectively, log-rank P < .001). The adjusted hazard ratios of moderate and severe congestion relative to mild congestion were 1.205 (95% confidence interval [CI], 1.065-1.365; P = .003) and 1.247 (95% CI, 1.103-1.410; P < .001), respectively. Among 3445 patients discharged alive, 85% had CCS of 0 (complete decongestion) and 15% had a CCS of 1 or more (residual congestion) at discharge. Although residual congestion predicted a risk of postdischarge death or HF hospitalization (adjusted hazard ratio, 1.314 [1.145-1.509]; P < .001), the admission CCS correlated with the risk of postdischarge death or HF hospitalization, even in the complete decongestion group. No correlation was observed for postdischarge death or HF hospitalization between residual congestion at discharge and admission CCS (P for the interaction = .316). CONCLUSIONS: In total, 85% of patients were discharged with complete decongestion in Japanese clinical practice. Clinical congestion, on admission and at discharge, was of prognostic value. The severity of congestion on admission was predictive of adverse outcomes, even in the absence of residual congestion. CLINICAL TRIAL REGISTRATION: https://clinicaltrials.gov/ct2/show/NCT02334891 (NCT02334891) https://upload.umin.ac.jp/cgi-open-bin/ctr_e/ctr_view.cgi?recptno=R000017241 (UMIN000015238).

Zero-Contrast Left Atrial Appendage Closure in Patients With Chronic Kidney Disease.

BACKGROUND: Left atrial appendage closure (LAAC) usually requires contrast medium during the procedure. However, patients with chronic kidney disease (CKD) are at high risk of developing contrast nephropathy. This study aimed to assess the safety and feasibility of zero-contrast LAAC in patients with CKD.Methods and Results: Zero-contrast LAAC was attempted in 15 patients with CKD Stages 3b-5 who were not on hemodialysis. All procedures were performed successfully, without any periprocedural complications. At the 45-day follow-up, no device-related complications or acute kidney disease were observed. CONCLUSIONS: The strategy of zero-contrast LAAC in patients with CKD can be an acceptable option.

Starting Neurohormonal Antagonists in Patients With Acute Heart Failure With Mid-Range and Preserved Ejection Fraction.

BACKGROUND: The clinical benefits of neurohormonal antagonists for patients with heart failure (HF) with mid-range and preserved ejection fraction (HFmrEF and HFpEF) are uncertain.Methods and Results: This study analyzed 858 consecutive patients with HFmrEF (EF: 40-49%) or HFpEF (EF ≥50%), who were hospitalized for acute HF, and who were discharged alive, and were not taking angiotensin-converting enzyme inhibitors (ACE)-I/ angiotensin II receptor blockers (ARB) or ß-blockers at admission. The study population was classified into 4 groups according to the status of prescription of ACE-I/ARB and ß-blocker at discharge: no neurohormonal antagonist (n=342, 39.9%), ACE-I/ARB only (n=128, 14.9%), ß-blocker only (n=189, 22.0%), and both ACE-I/ARB and ß-blocker (n=199, 23.2%) groups. The primary outcome measure was a composite of all-cause death or HF hospitalization. The cumulative 1-year incidence of the primary outcome measure was 41.2% in the no neurohormonal antagonist group, 34.0% in the ACE-I/ARB only group, 28.6% in the ß-blocker only group, and 16.4% in the both ACE-I/ARB and ß-blocker group (P<0.001). Compared with the no neurohormonal antagonist group, both the ACE-I/ARB and ß-blocker groups were associated with a significantly lower risk for a composite of all-cause death or HF hospitalization (HR: 0.46, 95% CI: 0.28-0.76, P=0.002). CONCLUSIONS: In hospitalized patients with HFmrEF and HFpEF, starting both ACE-I/ARB and a ß-blocker was associated with a reduced risk of the composite of all-cause death or HF hospitalization compared with patients not starting on an ACE-I/ARB or ß-blocker.

Impact of tapered-shape left ventricular outflow tract on pacemaker rate after transcatheter aortic valve replacement.

Mechanical compression of left ventricular outflow tract (LVOT) was reported to be a leading cause of conduction impairment requiring permanent pacemaker implantation (PPI) after transcatheter aortic valve replacement (TAVR). However, the association between tapered-shape LVOT and PPI after TAVR has not been elucidated. Of 272 consecutive patients treated with SAPIEN 3 in our institute, we retrospectively analyzed the clinical data of 256 patients without previous PPI or bicuspid valve. In-hospital PPI was performed in 20 (7.8%) patients at 8.2 ± 2.9 days after TAVR. Patients requiring PPI had smaller LVOT area (356.3 vs. 399.4 mm2, p ≤ 0.011). Moreover, receiver operating characteristic statistics showed that LVOT area /annulus area possessed significantly higher predictive ability than LVOT area (c-statistic: 0.91 [95% confidence interval [CI]: 0.84-0.95] vs. 0.67 [95% CI: 0.57-0.77], p < 0.001). Multivariable analysis revealed that LVOT area /annulus area (odds ratio [OR]: 1.93 [95% CI: 1.38-2.71]; p < 0.001 per % of decreasing), the difference between membranous septum length and implantation depth (ΔMSID) (OR: 6.82 [95% CI 2.39-19.48]; p < 0.001 per mm of decreasing) and pre-existing complete right bundle branch block (CRBBB) (OR: 32.38 [95% CI2.30-455.63]; p ≤ 0.002) were independently associated with PPI. In our study, tapered-shape LVOT as well as short ΔMSID and pre-existing CRBBB were identified as independent predictors for PPI after TAVR. Higher valve implantation is required to minimize the risk of post-procedural PPI especially for patients with short MS length, pre-procedural CRBBB, or tapered-shape LVOT.

Mid-term impact of underfilling and overfilling of the SAPIEN 3 balloon-expandable transcatheter aortic valve implantation on mortality and valve function.

At present, underfilling or overfilling the volume of the balloon-expandable transcatheter heart valve (THV) is generally utilized in transcatheter aortic valve implantation (TAVI). However, no research has assessed the clinical impact of filling volume variations of the current-generation SAPIEN 3 THV. We analyzed the clinical data of 331 patients who underwent TAVI with SAPIEN 3 at our institution. Post-procedural echocardiographic and multidetector computed tomography (MDCT) scan data and 3-year prognoses according to each filling volume were assessed. The procedural outcomes and 3-year mortality rates were comparable among the underfilling, nominal filling, and overfilling groups. For all THV sizes, the THV area evaluated on post-procedural MDCT scan increased stepwise along with an elevated filling volume, thereby covering a wide range of native annulus area. Compared with patients in the nominal filling and overfilling groups, those with 23-mm THVs in the underfilling group had a smaller effective orifice area (EOA) (1.38 [IQR: 1.18-1.56] vs. 1.57 [IQR: 1.41-1.84] vs. 1.58 [IQR: 1.45-1.71] cm2, P = 0.02) and a higher mean transvalvular gradient (13.6 [IQR: 11.0-15.7] vs. 12.1 [IQR: 9.0-14.9] vs. 12.0 [IQR: 8.1-14.8] cm2, P = 0.04). In conclusion, by adjusting the filling volume of SAPIEN 3 using THV with limited sizes, continuously distributed native annulus areas were covered. The underfilling implantation technique had a minimal negative effect on the valve function of 23-mm THVs only. In the entire cohort, the filling volume variations did not affect the mid-term prognosis negatively.

Activating Nitrogen-doped Graphene Oxygen Reduction Electrocatalysts in Acidic Electrolytes using Hydrophobic Cavities and Proton-conductive Particles.

Although pyridinic-nitrogen (pyri-N) doped graphene is highly active for the oxygen reduction reaction (ORR) of fuel cells in alkaline media, the activity critically decreases under acidic conditions. We report on how to prevent the deactivation based on the mechanistic understanding that O 2 + p y r i - N H + + e - → O 2 , a + p y r i - N H ${{{\rm O}}_{2}+{\rm p}{\rm y}{\rm r}{\rm i}{\rm { -}}{\rm N}{{\rm H}}^{+}+{{\rm e}}^{-}{\to }_{\ }^{{\rm \ }}{{\rm O}}_{2,{\rm a}}+{\rm p}{\rm y}{\rm r}{\rm i}{\rm { -}}{\rm N}{\rm H}}$ governs the ORR kinetics. First, we considered that the deactivation is due to the hydration of pyri-NH+ , leading to a lower shift of the redox potential. Introducing the hydrophobic cavity prevented the hydration of pyri-NH+ but inhibited the proton transport. We then increased proton conductivity in the hydrophobic cavity by introducing SiO2 particles coated with ionic liquid polymer/Nafion® which kept the high onset potentials with an increased current density even in acidic media.

Clinical Outcomes After Percutaneous Coronary Intervention in Patients With Cancer.

BACKGROUND: The aim of this study is to evaluate clinical outcomes after percutaneous coronary intervention (PCI) in patients with cancer.Methods and Results:Cancer screening was recommended before PCI in consecutive 1,303 patients who underwent their first PCI. By using cancer screening, cancer was diagnosed in 29 patients (2.2%). In total, 185 patients had present or a history of cancer. Patients with cancer more often suffered from non-cardiac death than those without (4.4% vs. 1.5%, P=0.006), and patients with cancer requiring ongoing therapy (n=18) more often suffered from major bleeding compared with those with recently (≤12 months) diagnosed cancer who do not have ongoing therapy (n=59) (16.7% vs. 3.4%, P=0.049). During the 1-year follow up, 25 patients (2.0%) were diagnosed as having cancer, in which 48.0% of bleeding events led to a cancer diagnosis. Patients with high bleeding risk according to the Academic Research Consortium for high bleeding risk (ARC-HBR) were associated with a greater 1-year major bleeding risk than those without high bleeding risk in patients with (7.9% vs. 0.0%, P=0.02) and without cancer (7.1% vs. 2.5%, P<0.001), respectively. CONCLUSIONS: Cancer was diagnosed in 2.2% of 1,303 unselected patients before PCI by cancer screening and in 2.0% within 1-year after PCI. Cancer was associated with a greater risk of non-cardiac death, whereas ongoing active cancer was associated with greater risk of major bleeding. ARC-HBR criteria successfully identified high-bleeding risk patients, irrespective of the presence or absence of cancer.

Effect of postdilatation following balloon expandable transcatheter aortic valve implantation.

BACKGROUND: Postdilatation after transcatheter heart valve (THV) implantation was associated with larger aortic valve areas in large-scale registries; however, the specific effects of postdilatation are poorly understood. METHODS AND RESULTS: Among a total of 224 consecutive patients who underwent transcatheter aortic valve replacement using SAPIEN 3, 121 patients (54.0%) underwent postdilatation (same contrast volume: N = 101, +1 ml: N = 17, +2 ml: N = 3). THV diameter was assessed (a) during, (b) after implantation, (c) during postdilatation, and (d) after postdilatation by quantitative fluoroscopy. In the overall patients (N = 224), acute recoil was observed from during implantation (23.0 ± 2.0 mm) to after implantation (22.5 ± 2.0 mm, p < .001) with an absolute recoil of 0.52 ± 0.25 mm. After postdilatation (N = 121), THV diameter significantly increased from 22.5 ± 2.0 mm to 22.9 ± 2.1 mm (p < .001), with smaller absolute recoil (0.39 ± 0.21 mm, p < .001). Compared with those who did not undergo postdilatation, patients who underwent postdilatation had larger postprocedural THV area assessed by multi-slice computed tomography (471.4 ± 78.1 mm2 vs. 447.5 ± 76.3 mm2 , p = .02) and larger effective orifice area (EOA) assessed by echocardiography throughout 1 year (at 30 day, 1.66 ± 0.33 cm2 vs. 1.45 ± 0.27 cm2 , p < .001; at 6 month, 1.66 ± 0.33 cm2 vs. 1.44 ± 0.29 cm2 , p < .001; at 1 year, 1.69 ± 0.38 cm2 vs. 1.47 ± 0.30 cm2 , p < .001). CONCLUSIONS: Postdilatation after implantation of the SAPIEN 3 valve produced a larger THV diameter with less acute recoil, followed by larger EOA throughout 1 year. Further studies are needed to evaluate the impact of postdilatation on long-term clinical outcomes.

Aortic Complex Rupture After Transcatheter Aortic Valve Implantation.

Aortic complex rupture is one of the most critical complications associated with transcatheter aortic valve implantation (TAVI). Its incidence is rare, and its mechanism varies by case; therefore, it is difficult to identify the predictors of complex rupture. Herein, we report a clinical case series of aortic complex rupture. Within our cohort, the frequency of complex rupture was 0.8% (4/497 consecutive patients) with an in-hospital mortality of 0. Among these four patients with complex rupture, two underwent emergent thoracotomy and surgical hemostasis without a heart-lung machine and surgical aortic valve replacement, whereas the other two were conservatively managed. The case overview revealed the following similarities: all the patients were elderly, small women; balloon-expandable valves were used; the annulus area was small with heavily calcified leaflet; and aggressive treatment strategy was used (i.e., oversizing and post-dilatation). In such cases, TAVI should be performed with a careful strategy. Once aortic complex rupture occurs, damage can be minimized through cooperation with an institutional heart team and calm management.

Demographics, Management, and In-Hospital Outcome of Hospitalized Acute Heart Failure Syndrome Patients in Contemporary Real Clinical Practice in Japan　- Observations From the Prospective, Multicenter Kyoto Congestive Heart Failure (KCHF) Registry.

BACKGROUND: There is a scarcity of reports on the clinical characteristics and management practice in contemporary all-comer patients with acute decompensated heart failure (ADHF). Methods and Results: The Kyoto Congestive Heart Failure (KCHF) registry is a prospective observational cohort study enrolling 4,056 consecutive patients who had hospital admission due to ADHF without any exclusion criteria between October 2014 and March 2016 in the 19 participating hospitals in Japan. Baseline characteristics, clinical presentations, management, and in-hospital outcomes were compared between heart failure (HF) with reduced left ventricular ejection fraction (LVEF; HFrEF, LVEF <40%), HF with mid-range LVEF (HFmrEF, LVEF 40-49%), and HF with preserved LVEF (HFpEF, LVEF ≥50%). Of the 4,041 patients with documented LVEF, 1,744 (43%) had HFpEF; 746 (19%), HFmrEF; and 1,551 (38%), HFrEF. The median age was 80 years (IQR, 72-86 years) in the entire population, and was higher with increasing LVEF (P<0.001). The in-hospital mortality rate was higher in the HFrEF than in the HFmrEF and HFpEF groups (9.2%, 4.8%, and 5.1%, respectively, P<0.001). CONCLUSIONS: This registry elucidated the clinical features and clinically relevant in-hospital outcomes in contemporary consecutive patients with ADHF in real-world clinical practice in Japan. When classified by LVEF, significant differences in characteristics and in-hospital outcomes existed between patients with HFrEF, HFmrEF, and HFpEF.

USAXS analysis of concentration-dependent self-assembling of polymer-brush-modified nanoparticles in ionic liquid: [I] concentrated-brush regime.

Using ultra-small angle X-ray scattering (USAXS), we analyzed the higher-order structures of nanoparticles with a concentrated brush of an ionic liquid (IL)-type polymer (concentrated-polymer-brush-modified silica particle; PSiP) in an IL and the structure of the swollen shell layer of PSiP. Homogeneous mixtures of PSiP and IL were successfully prepared by the solvent-casting method involving the slow evaporation of a volatile solvent, which enabled a systematic study over an exceptionally wide range of compositions. Different diffraction patterns as a function of PSiP concentration were observed in the USAXS images of the mixtures. At suitably low PSiP concentrations, the USAXS intensity profile was analyzed using the Percus-Yevick model by matching the contrast between the shell layer and IL, and the swollen structure of the shell and "effective diameter" of the PSiP were evaluated. This result confirms that under sufficiently low pressures below and near the liquid/crystal-threshold concentration, the studied PSiP can be well described using the "hard sphere" model in colloidal science. Above the threshold concentration, the PSiP forms higher-order structures. The analysis of diffraction patterns revealed structural changes from disorder to random hexagonal-closed-packing and then face-centered-cubic as the PSiP concentration increased. These results are discussed in terms of thermodynamically stable "hard" and/or "semi-soft" colloidal crystals, wherein the swollen layer of the concentrated polymer brush and its structure play an important role.

Impact of total stent length after cobalt chromium everolimus-eluting stent implantation on 3-year clinical outcomes.

OBJECTIVES: The objective was to assess whether total stent length (TSL) after cobalt-chromium everolimus-eluting stent (CoCr-EES) implantation was associated with long-term clinical outcomes. BACKGROUND: The impact of TSL after CoCr-EES implantation on long-term clinical outcomes remained unclear. METHODS: A total of 1,007 consecutive patients with 1,382 lesions treated only with CoCr-EES were analyzed. Patients and lesions were divided into tertile group: TSL per patient (TSL-P) (PA [8-23 mm], n = 382; PB [23-46 mm], n = 312; and PC [46-204 mm], n = 313), and TSL per lesion (TSL-L) (LA [8-18 mm], n = 486; LB [18-28 mm], n = 475; and LC [28-140 mm], n = 421). The cumulative 3-year incidence of clinically driven target-lesion revascularization (CD-TLR) and definite stent thrombosis (ST) based on TSL-P and TSL-L groupings were accessed. RESULTS: After inverse probability of weighted adjustment, the cumulative 3-year incidence of CD-TLR for the TSL-P and TSL-L were higher in the PC and LC groups than in the other groups (hazard ratio [HR] 2.92, 95% confidence intervals [CI] 1.66-5.15, P < 0.001 vs. PA; HR 2.49, 95% CI 1.47-4.20, P < 0.001 vs. PB; HR 1.94, 95% CI 1.15-3.28, P = 0.01 vs. LA; HR 2.80, 95% CI 1.73-4.54, P < 0.001 vs. LB, respectively). No significant differences in the cumulative 3-year incidence of definite ST were observed in both TSL-P and TSL-L groups. CONCLUSIONS: TSL after CoCr-EES implantation has significantly impact on CD-TLR rate through 3 years, but it is not associated with an increased incidence of definite ST. © 2016 Wiley Periodicals, Inc.

Early Safety and Efficacy of Transcatheter Aortic Valve Implantation for Asian Nonagenarians (from KMH Registry).

As Japan has one of the most rapidly aging populations in the world, transcatheter aortic valve implantation (TAVI) is likely to be performed in increasing numbers of older people. There is little information on either the efficacy or the safety of TAVI in nonagenarians in Asia.From October 2013 to June 2015, 112 consecutive patients underwent TAVI with Edwards SAPIEN XT valves in our institution. We compared 25 patients aged at least 90 years (mean 91.6 ± 1.7 years) with 87 patients aged under 90 years (mean 82.5 ± 6.0 years) at the time of TAVI. All definitions of clinical endpoints and adverse events were based on the Valve Academic Research Consortium 2 definitions.The median follow-up interval was 561.5 days (the first and third quarters, 405.0 and 735.8 days). Nonagenarians had a higher logistic European System for Cardiac Operative Risk Evaluation (EuroSCORE), Euro II score, and the Society of Thoracic Surgeons predictive risk of mortality (STS) score, and a prevalence of clinical frailty scale ≥ 4. The rate of device success, and the 30-day and 6-month mortalities were not different between patients aged ≥ 90 years and < 90 years (96.0% versus 92.0%, P = 0.68; both 0%, P = 1.00; 4.0% versus 3.5%, P = 0.32, respectively). At six months, clinical efficacy and time-related valve safety were also similar in the two groups (12.5% versus 13.4%, P = 1.00; 4.5% versus 10.3%, P = 0.68, respectively). The cumulative 1-year mortalities were not significantly different between the two groups (8.4% versus 9.4%, P = 0.94, respectively).TAVI can contribute to acceptable clinical results and benefits in a carefully selected group of nonagenarians in Asia.

Two-year clinical outcomes of the NOBORI biolimus-eluting stents versus XIENCE/PROMUS everolimus-eluting stents in small vessel disease.

BACKGROUND: Biolimus-eluting stents (BES) have similar efficacy and safety compared with cobalt chromium everolimus-eluting stents (CoCr-EES), whereas it is unclear whether the same applies to small vessel disease. We sought compare clinical outcomes between BES and CoCr-EES in patients with small vessel disease. METHODS AND RESULTS: A total of 1,132 patients treated only with BES (612 patients) or EES (520 patients) in small vessel disease (stent size 2.5-mm) were retrospectively analyzed. We assessed the cumulative 2-year incidence of major adverse cardiovascular events (MACE), defined as a composite of cardiac death, myocardial infarction (MI), definite stent thrombosis (ST), and clinically driven target lesion revascularization (CD-TLR). The cumulative 2-year incidence of MACE was similar between the two groups (12.1% vs. 11.8%, P = 0.77). The cumulative incidence of cardiac death, CD-TLR, and definite ST were also not significantly different between both groups (3.2% vs. 3.6%, P = 0.78; 8.3% vs. 8.4%, P = 1.00; 0.33% vs. 0.21%, P = 0.66, respectively). After multivariate adjusting, the adjusted risk of BES group relative to CoCr-EES group for MACE was not significantly different (hazard ratio [HR]: 0.78, 95% confidential interval [CI]: 0.53-1.15, P = 0.20). Similarly, no significant difference in the adjusted risks for cardiac death and CD-TLR were observed between the two groups (HR: 0.62, 95% CI: 0.28-1.37, P = 0.24; HR: 0.81, 95% CI: 0.51-1.29, P = 0.38). CONCLUSIONS: Two-year clinical outcomes of BES are similar to those of CoCr-EES in patients with small vessel disease. The use of BES is acceptable for small coronary artery disease. © 2015 Wiley Periodicals, Inc.

Lubrication Properties of Ammonium-Based Ionic Liquids Confined between Silica Surfaces Using Resonance Shear Measurements.

To evaluate the friction properties of new lubrication systems, two types of ammonium-based ionic liquids (ILs), N,N-diethyl-N-methyl-N-(2-methoxyethyl) ammonium tetrafluoroborate ([DEME][BF4]) and N,N-diethyl-N-methyl-N-(2-methoxyethyl) ammonium bis(trifluoromethanesulfonyl) imide ([DEME][TFSI]), were investigated by resonance shear measurements (RSM) and reciprocating type tribotests between silica (glass) surfaces. RSM revealed that an IL layer of ca. 2 nm in thickness was maintained between the silica surfaces under an applied load of 0.40 mN ∼ 1.2 mN. The relative intensity of the RMS signal indicated that the friction of the system was lower for [DEME][BF4], 0.12, than that of [DEME][TFSI], 0.18. On the other hand, the friction coefficients µk obtained from the tribotests of [DEME][BF4] were lower than that of [DEME][TFSI] for sliding velocities in the range of 5.0 × 10(-4) m s(-1) to 3.0 × 10(-2) m s(-1) under applied loads of 196-980 mN. The friction coefficients obtained by the tribotest are discussed with reference to the RSM results.

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. METHODS AND RESULTS: 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.

Immobilization of semisoft colloidal crystals formed by polymer-brush-afforded hybrid particles.

An immobilization technique for semisoft colloidal crystals, which are ordered arrays of polymer-brush-afforded hybrid particles synthesized by surface-initiated living radical polymerization (SI-LRP), is reported. Silica particles were first grafted with well-defined block copolymers of poly(methyl methacrylate-co-hydroxyethyl methacrylate)-b-poly(methyl methacrylate), P(MMA-co-HEMA)-b-PMMA by SI-LRP, which gave a graft density as high as 0.7 chains/nm(2). The HEMA units reacted with 2-isocyanatoethyl methacrylate to introduce vinyl groups at the outer layer of the polymer-brush shell. The modified hybrid particles formed a colloidal crystal in a solution containing a small amount of free polymers with vinyl groups. The colloidal crystal was photoirradiated in the presence of a photoradical initiator to immobilize it through a cross-linking reaction among the vinyl groups. The structural analyses of the colloidal crystals before and after the photoirradiation were carried out by confocal laser scanning microscopy; the results showed that the periodic structures of the crystals were maintained after immobilization.