Rapidly Progressive Stenosis of the Left Main Trunk Ostium Starting 21 Months After Stent Implantation.

Rapidly progressive in-stent restenosis (ISR) after stent deployment from the left main trunk (LMT) to the left anterior descending artery (LAD) without plaque at the LMT ostium has not been reported. A 60-year-old Japanese man with a history of scleroderma, pulmonary fibrosis, and type 2 diabetes developed acute myocardial infarction of the right coronary artery (RCA) and was treated by emergency percutaneous coronary intervention (PCI) for RCA. Nine days later he underwent PCI from the LMT to the LAD. Follow-up coronary angiography (CAG) at 9 and 21 months post-PCI did not reveal ISR in any lesion, but the patient experienced cardiac arrest at 25 months post-PCI. Emergency CAG after resuscitation revealed ISR of the LMT ostium; emergency PCI was conducted. The development of ISR at the ostium of the LMT although the patient was free of plaque 4 months before is extremely unusual. This rare ISR of the LMT ostium progressed rapidly after follow-up CAG revealed no ISR at 21 months post-stent implantation.

Initial experience with the subcutaneous implantable cardioverter-defibrillator in a single Japanese center.

BACKGROUND: The subcutaneous implantable cardioverter-defibrillator (S-ICD) is recognized as a viable alternative to the transvenous ICD. The safety and efficacy of this device has been demonstrated in Western countries, but studies with S-ICD implantation in Japanese patients have not been reported. METHODS AND RESULTS: Twelve patients received an S-ICD implant in our institute between February and September 2016. All S-ICDs were successfully implanted without complications. One appropriate and one inappropriate therapy was identified. CONCLUSIONS: S-ICD implantation appears to provide a viable alternative to transvenous ICD implantation for some Japanese patients. However, we should perform careful follow-up of patients to eliminate inappropriate therapy.

Serum cystatin C levels are associated with coronary artery calcification in women without chronic kidney disease.

BACKGROUND: Chronic renal disease (CKD) is a determinant of coronary artery calcification (CAC), which is a predictor of cardiovascular events. However, in a population without CKD, the association between CAC and renal function is unclear. CAC is affected by sex. This study aimed to determine whether serum cystatin C, a sensitive marker of kidney function, or sex differences are associated with CAC in patients without CKD. METHODS: We evaluated 456 consecutive patients (61±13 years, 42% women) without CKD and evidence of coronary artery disease. The CAC (Agatston) score was examined by multidetector computed tomography. RESULTS: When patients were categorized into three CAC groups based on the Agatston score, mild (<10), moderate (11-399), and severe (≥400) in each sex, serum cystatin C levels gradually increased by severity of CAC in women, but not men. Receiver operating characteristic curve analysis showed that, in women, a cut-off value of 0.97mg/l for cystatin C discriminated patients with severe CAC with a sensitivity of 71% and specificity of 77% (area under the curve, 0.74; 95% CI: 0.62-0.86; p<0.01). Multivariate logistic analysis showed that serum cystatin C was not associated with severe CAC in all patients and men, but this association was observed in women (OR: 7.80 for cystatin C≥0.97mg/l, 95% CI: 1.76-34.6, p<0.01). CONCLUSION: Higher serum cystatin C levels are associated with greater CAC in women without CKD. Measurement of cystatin C may be useful for identifying women who are at high risk for cardiovascular disease.

Epicardially placed implantable cardioverter-defibrillator for a child with congenital long QT syndrome.

A 7-year-old boy presented at our hospital with syncope. At birth, electrocardiography had shown a long QT interval with torsade de pointes (TdP). Congenital long QT syndrome (LQTS) had been diagnosed by genetic testing, and was successfully controlled with oral propranolol. At age 7, TdP had recurred with syncope. Electrocardiography revealed a prominent long QT interval with T-wave alternans. The propranolol dose was increased, but TdP remained uncontrolled. A cardioverter-defibrillator (ICD) was implanted epicardially, and TdP completely resolved with atrial pacing. We report this rare case of ICD implantation in a child with LQTS.

Comparison of longevity and clinical outcomes of implantable cardioverter-defibrillator leads among manufacturers.

BACKGROUND: An early failure of the Biotronik Linox S/SD implantable cardioverter-defibrillator (ICD) lead has been reported. We have also experienced several cases with early failure of Linox leads. OBJECTIVE: Our aim was to assess the longevity of Linox S/SD (Biotronik, Berlin, Germany) compared with Sprint Fidelis (Medtronic, Minneapolis, MN), Sprint Quattro (Medtronic), and Endotak Reliance (Boston Scientific, Natick, Massachusetts) leads. METHODS: We retrospectively reviewed patients who had undergone implantation of Linox S/SD (n = 90), Sprint Fidelis (n = 37), Sprint Quattro (n = 27), or Endotak Reliance (n = 50) leads between June 2000 and December 2013 at our hospital. Variables associated with lead failure were assessed by the Kaplan-Meier method and Cox survival modeling. RESULTS: Failure rates of Linox, Sprint Fidelis, and Endotak leads were 3.2%/year (7-year survival rate, 81.0%), 3.4%/year (7-year survival rate, 77.2%), and 0.61%/year (7-year survival rate, 95.8%), respectively. No lead failure was found with Sprint Quattro leads. The survival probability of Linox leads was significantly lower than that of Endotak leads (P = .049) and comparable to that of Sprint Fidelis leads (P = .69). In univariate analysis, age was the only predictor of Linox lead failure. Patients <58 years old were at significantly increased risk of lead failure compared with patients ≥58 years old (hazard ratio, 9.0; 95% confidence interval, 1.13-71.3; P = .037). CONCLUSION: In our single-center experience, the survival rate of Linox leads was unacceptably low. The only predictor of Linox lead failure was age at implantation. This is the first description of a lower survival rate for Linox leads in an Asian population.

Two cases of inappropriate implantable cardioverter-defibrillator therapies due to T wave oversensing induced by body twisting.

T wave oversensing (TWOS) is a common cause of inappropriate implantable cardioverter-defibrillator (ICD) therapies. Various algorithms to avoid inappropriate ICD therapy are available; however, they are not helpful to avoid TWOS. Although the reproduction of TWOS is useful to resolve the problem of TWOS, it is sometimes difficult to reproduce TWOS. We report two cases of inappropriate ICD therapy due to TWOS, which were induced only by body twisting. We can successfully manage the device based on the evidence of reproduced TWOS.

Complete right bundle branch block and QRS-T discordance can be the initial clue to detect S-ICD ineligibility.

BACKGROUND: In order to minimize inappropriate shocks of subcutaneous implantable cardioverter-defibrillators (S-ICD), it is important to recognize who is suitable for S-ICD indication. This study aimed to clarify what types of cardiac disease are likely to fulfill the S-ICD screening criteria and ineligible factors for S-ICD in the standard 12-lead electrocardiogram (ECG). METHODS: A total of 348 patients with heart disease were enrolled. They were assessed by supine and standing ECG recording to simulate the 3 S-ICD sensing vectors and standard 12-lead ECG, simultaneously. Clinical and ECG characteristics were analyzed to compare the patients who are eligible and ineligible with S-ICD screening ECG indication. RESULTS: The mean age of study patients was 49±21 years and 244 (70%) were men. Nineteen percent of patients were unsuitable for S-ICD. There was no significant difference in ineligibility for S-ICD among cardiac diseases (p=0.48). Univariate analysis showed complete right bundle branch block (CRBBB), QRS-T discordance in lead II, and QRS-T discordance in 3 leads (I, II, and aVF) were more frequent in patients who were ineligible for S-ICD than in the eligible group. Multivariate regression analysis showed CRBBB and QRS-T discordance in 3 leads were independent predictors for ineligibility of S-ICD. CONCLUSION: There are no differences in eligibility of S-ICD among types of cardiac diseases. CRBBB and QRS-T discordance were independent predictors for ineligibility.

C-H cleavage and double alkyl additions to the disulfido ligand in dicyanido-bridged Ru2S2 complexes.

Novel dicyanido-bridged dicationic RuIIISSRuIII complexes [{Ru(P(OCH3)3)2}2(mu-S2)(mu-X)2{mu-m-C6H4(CH2CN)2}](CF3SO3)2 (4, X=Cl, Br) were synthesized by the abstraction of the two terminal halide ions of [{RuX(P(OCH3)3)2}2(mu-S2)(mu-X)2] (1, X=Cl, Br) followed by treatment with m-xylylenedicyanide. 4 reacted with 2,3-dimethylbutadiene to give the C4S2 ring-bridged complex [{Ru(P(OCH3)3)2}2{mu-SCH2C(CH3)=C(CH3)CH2S}(mu-X)2{mu-m-C6H4(CH2CN)2}](CF3SO3)2 (6, X=Cl, Br). In addition, 4 reacted with 1-alkenes in CH3OH to give alkenyl disulfide complexes [{Ru(P(OCH3)3)2}2{mu-SS(CH2C=CHR)}(mu-Cl)2{mu-m-C6H4(CH2CN)2}](CF3SO3) (7: R=CH2CH3, 9: R=CH2CH2CH3) and alkenyl methyl disulfide complexes [{Ru(P(OCH3)3)2}2{mu-S(CH3)S(CH2C=HR)}(mu-Cl)2{mu-m-C6H4(CH2CN)2}](CF3SO3)2 (8: R=CH2CH3, 10: R=CH2CH2CH3) via the activation of an allylic C-H bond followed by the elimination of H+ or condensation with CH3OH. Additionally, the reaction of 4 with 3-penten-1-ol gave [{Ru(P(OCH3)3)2}2{mu-SS(CH2C=CHCH2OH)}(mu-Cl)2{mu-m-C6H4(CH2CN)2}](CF3SO3) (11) via the elimination of H+ and [{Ru(P(OCH3)3)2}2(mu-SCH2CH=CHCH2S)(mu-Cl)2{mu-m-C6H4(CH2CN)2}](CF3SO3)2 (12) via the intramolecular elimination of a H2O molecule. 12 was exclusively obtained from the reaction of 4 with 4-bromo-1-butene.

Preparation, characterization, and magnetic behavior of the ln derivatives (ln = nd, la) of a 2,6-diiminepyridine ligand and corresponding dianion.

An unprecedented Nd[2,6-[[2,6-(i-Pr)(2)C(6)H(5)]N=C(CH(3))](2)(C(5)H(3)N)]NdI(2)(THF) (1) complex was prepared by oxidizing metallic Nd with I(2) in THF and in the presence of 2,6-[[2,6-(i-Pr)(2)C(6)H(5)]N=C(CH(3))](2)(C(5)H(3)N). The magnetic behavior at variable T clearly indicated that the complex should be regarded as a trivalent Nd atom antiferromagnetically coupled to a radical anion. By using the doubly deprotonated form of the diimino pyridine ligand [[2,6-[[2,6-(i-Pr)(2)C(6)H(5)]N-C=CH(2)](2)(C(5)H(3)N)](2-) (2) the corresponding trivalent complexes [[2,6-[[2,6-(i-Pr)(2)C(6)H(5)]N-C=CH(2)](2)(C(5)H(3)N)]Ln (THF)](mu-Cl)(2)[Li(THF)(2)].0.5 (hexane) [Ln = Nd (3), La (4)] were obtained and characterized. Reduction of these species afforded electron transfer to the ligand system which gave ligand dimerization via C-C bond formation through one of the two ene-amido functions of each molecule. The resulting dinuclear [[([2,6-(i-Pr)(2)C(6)H(5)]N-C=(CH(2)))(C(5)H(3)N)([2,6-(i-Pr)(2)C(6)H(5)]N=CCH(2))]Ln(THF)(2)(mu-Cl)[Li(THF)(3)])(2).2(THF) [Ln = Nd (5), La (6)] were isolated and characterized.

Elimination of HX (X = Cl, Br) from haloalkenes on the Ru2Q2 (Q = S, Se) core complex.

Treatment of [[Ru(P(OCH3)3)2(CH3CN)3]2(mu-Q2)](CF3SO3)4 (1, Q = S; 2, Q = Se) with haloalkenes resulted in the formation of complexes carrying unsaturated C3Q2 five-membered or C4Q2 six-membered rings via elimination of HX (X = Cl, Br). The reactions of 1 and 2 with allyl bromide gave the corresponding addition products, [[Ru(P(OCH3)3)2(CH3CN)3]2(mu-QCH=CHCH2Q)](CF3SO3)4 (3, Q = S; 4, Q = Se), via elimination of HBr. The elimination process seems to be thermodynamically controlled and takes place at the final stage of the reaction. The steric effect of the halogen atoms seems more operative than the electronic one.

Organometallic-like C-H bond activation and C-S bond formation on the disulfide bridge in the RuSSRu core complexes.

C-S bond formations on the disulfide bridge in the dinuclear Ru(III) complexes have been found in the reaction with unsaturated organic molecules, such as alkenes and ketones. The reactions are initiated by the organometallic-like C-H bond activation. Through the mechanistic study of these novel reactions, the specific nature of the disulfide bridging ligand has been unveiled: (i) the double bond character of the sulfur-sulfur bond, which allows the Diels-Alder-type [4 + 2] cycloaddition reaction with butadiene to form a C(4)S(2) ring, (ii) the C-H bond activation on the S-S bond forming a C-S bond. All of the C-H activation reactions and the ensuing C-S bond formation reactions suggest that the disulfide ligand can act in a manner similar to the transition metal centers of the organometallic complexes.

Dehydration reaction of hydroxyl substituted alkenes and alkynes on the Ru(2)S(2) complex.

A variety of inter- and intramolecular dehydration was found in the reactions of [[Ru(P(OCH(3))(3))(2)(CH(3)CN)(3)](2)(mu-S(2))](CF(3)SO(3))(4) (1) with hydroxyl substituted alkenes and alkynes. Treatment of 1 with allyl alcohol gave a C(3)S(2) five-membered ring complex, [[Ru(P(OCH(3))(3))(2)(CH(3)CN)(3)](2)[mu-SCH(2)CH(2)CH(OCH(2)CH=CH(2))S]](CF(3)SO(3))(4) (2), via C-S bond formation after C-H bond activation and intermolecular dehydration. On the other hand, intramolecular dehydration was observed in the reaction of 1 with 3-buten-1-ol giving a C(4)S(2) six-membered ring complex, [[Ru(P(OCH(3))(3))(2)(CH(3)CN)(3)](2) [mu-SCH(2)CH=CHCH(2)S]](CF(3)SO(3))(4) (3). Complex 1 reacts with 2-propyn-1-ol or 2-butyn-1-ol to give homocoupling products, [[Ru(P(OCH(3))(3))(2)(CH(3)CN)(3)](2)[mu-SCR=CHCH(OCH(2)C triple bond CR)S]](CF(3)SO(3))(4) (4: R = H, 5: R = CH(3)), via intermolecular dehydration. In the reaction with 2-propyn-1-ol, the intermediate complex having a hydroxyl group, [[Ru(P(OCH(3))(3))(2)(CH(3)CN)(3)](2)[mu-SCH=CHCH(OH)S]](CF(3)SO(3))(4) (6), was isolated, which further reacted with 2-propyn-1-ol and 2-butyn-1-ol to give 4 and a cross-coupling product, [[Ru(P(OCH(3))(3))(2)(CH(3)CN)(3)](2)[mu-SCH=CHCH(OCH(2)C triple bond CCH(3))S]](CF(3)SO(3))(4) (7), respectively. The reaction of 1 with diols, (HO)CHRC triple bond CCHR(OH), gave furyl complexes, [[Ru(P(OCH(3))(3))(2)(CH(3)CN)(3)](2)[mu-SSC=CROCR=CH]](CF(3)SO(3))(3) (8: R = H, 9: R = CH(3)) via intramolecular elimination of a H(2)O molecule and a H(+). Even though (HO)(H(3)C)(2)CC triple bond CC(CH(3))(2)(OH) does not have any propargylic C-H bond, it also reacts with 1 to give [[Ru(P(OCH(3))(3))(2)(CH(3)CN)(3)](2)[mu-SCH(2)C(=CH(2))C(=C=C(CH(3))(2))]S](CF(3)SO(3))(4) (10). In addition, the reaction of 1 with (CH(3)O)(H(3)C)(2)CC triple bond CC(CH(3))(2)(OCH(3)) gives [[Ru(P(OCH(3))(3))(2)(CH(3)CN)(2)][mu-S=C(C(CH(3))(2)OCH(3))C=CC(CH(3))CH(2)S][Ru(P(OCH(3))(3))(2)(CH(3)CN)(3)]](CF(3)SO(3))(4) (11), in which one molecule of CH(3)OH is eliminated, and the S-S bond is cleaved.

Participation of the alpha,alpha'-diiminopyridine ligand system in reduction of the metal center during alkylation.

The reaction of [[2,6-(i-Pr)(2)PhN=C(Me)](2)(C(5)H(3)N)]MnCl(2) with alkylating agents formed a dinuclear Mn(I) derivative via ligand reductive coupling. In the case of the trivalent Cr analogue, a similar reaction afforded reduction toward Cr(II) but also alkylation at the pyridine ring para position followed by an unprecedented cycloaddition that generated a tricyclic system.

The synthesis of a novel cyclo-Se3-bridged trinuclear Ru complex.

The reaction of [[RuCl[P(OCH3)3]2]2(mu-Se2)(mu-Cl)2] with four equivalents of NaPF6 gave [[Ru[P(OCH3)3]2(CH3CN)3]2(mu-Se2)](PF6)3 and [[Ru[P(OCH3)3]2(CH3CN)(mu-Cl)]2(mu-cyclo-Se3)[Ru[P(OCH3)3]2(CH3CN)3]](PF6)4. The former is a Ru(II) Ru(III) mixed-valent paramagnetic compound. The X-ray structural analysis of the latter compound revealed that it has a novel mu-cyclo-Se3 neutral ligand and three Ru(II) atoms.

Synthesis of Alkynechalcogenolato Complexes of Titanocene(IV) and Samarocene(III) and Formation of a Ti(2)Ni Trinuclear Cluster [Cp(2)Ti(&mgr;-SC&tbd1;CPh)(2)](2)Ni.

Reactions between (C(5)H(4)R')(2)TiCl(2) and 2 equiv of LiEC&tbd1;CR generated a series of alkynethiolato and alkyneselenolato complexes of titanocene(IV), (C(5)H(4)R')(2)Ti(EC&tbd1;CR)(2) in high yields (1, R = Ph, R' = H, E = S; 2, R = p-C(6)H(4)CH(3), R' = H, E = S; 3, R = (t)Bu, R' = H, E = S; 4, R = Ph, R' = Me, E = S; 5, R = Ph, R' = H, E = Se). Complex 1 reacted with (1)/(2) equiv of Ni(cod)(2) to give a linear Ti(2)Ni trimetallic complex, [Cp(2)Ti(&mgr;-SC&tbd1;CPh)(2)](2)Ni (6), in which the Ni atom links two Cp(2)Ti(SC&tbd1;CPh)(2) units through interactions with thiolate sulfur bridges. Treatment of Cp(2)Sm(&mgr;-Cl)(2)Li(OEt(2))(2) with 2 equiv of LiSC&tbd1;CPh and TMEDA resulted in [Li(tmeda)(2)][Cp(2)Sm(SC&tbd1;CPh)(2)] (7). The structures of complexes 4, 5, 6, and 7 were determined by X-ray diffraction analysis.