Angina has traditionally been thought to be caused by obstructive coronary artery disease (CAD). However, a substantial number of patients with angina are found to not have obstructive CAD when undergoing coronary angiography. A significant proportion of these patients have coronary microvascular dysfunction (CMD), characterized by heightened sensitivity to vasoconstrictor stimuli and limited microvascular vasodilator capacity. With the advent of non-invasive and invasive techniques, the coronary microvasculature has been more extensively studied in the past 2 decades. CMD has been identified as a cause of cardiac ischemia, in addition to traditional atherosclerotic disease and vasospastic disease. CMD can occur alone or in the presence obstructive CAD. CMD shares many similar risk factors with macrovascular CAD. Diagnosis is achieved through detection of an attenuated response of coronary blood flow in response to vasodilatory agents. Imaging modalities such as cardiovascular magnetic resonance, positron emission tomography, and transthoracic Doppler echocardiography have become more widely used, but have not yet completely replaced the traditional intracoronary vasoreactivity testing. Treatment of CMD starts with lifestyle modification and risk factor control. The use of traditional antianginal, antiatherosclerotic medications and some novel agents may be beneficial; however, clinical trials are needed to assess the efficacy of the pharmacologic and non-pharmacologic therapeutic modalities. In addition, studies with longer-term follow-up are needed to determine the prognostic benefits of these agents. We review the epidemiology, prognosis, pathogenesis, diagnosis, risk factors and current therapies for CMD.

Inherited arrhythmia disorders (IADs) are a group of potentially lethal diseases that remain diagnostic and management challenges. Although the genetic basis for many of these disorders is well known, the pathogenicity of individual mutations and the resulting clinical outcomes are difficult to predict. Treatment options remain imperfect, and optimizing therapy for individual patients can be difficult. Recent advances in the derivation of induced pluripotent stem cells (iPSCs) from patients and creation of genetically engineered human models using CRISPR/Cas9 has the potential to dramatically advance translational arrhythmia research. In this review, we discuss the current state of modeling IADs using human iPSC-derived cardiomyocytes. We also discuss current limitations and areas for further study.

The American Heart Association (AHA) Scientific Sessions 2016 were held on November 12–16 at the Ernest N. Morial Convention Center, New Orleans, LA. This 5-day event featured cardiovascular clinical practice covering all aspects of basic, clinical, population, and translational content. One of the hot topics at AHA 2016 was precision medicine. The key presentations and highlights from the AHA Scientific Sessions 2016, including “precision medicine” as one of the hot topics, are herein reported.

Background:Stanford type A acute aortic dissection (A-AAD) extends to the brachiocephalic branches in some patients. After ascending aortic replacement, a remaining re-entry tear in the distal brachiocephalic branches may act as an entry and result in a patent false lumen in the aortic arch. However, the effect of brachiocephalic branch re-entry concomitant with A-AAD remains unknown.

Methods and Results:Eighty-five patients with A-AAD who underwent ascending aortic replacement in which both preoperative and postoperative multiple-detector computed tomography (MDCT) scans could be evaluated were retrospectively studied. The presence of a patent false lumen in at least one of the brachiocephalic branches on preoperative MDCT was defined as brachiocephalic branch re-entry, and 41 patients (48%) had this. Postoperatively, 47 of 85 (55%) patients had a patent false lumen in the aortic arch. False lumen remained patent after operation in 34 out of the 41 (83%) patients with brachiocephalic branch re-entry, as compared to that in 13 of the 44 (30%) patients without such re-entry (P<0.001). Brachiocephalic branch re-entry was a significant risk factor for a late increase in the aortic arch diameter greater than 10 mm (P=0.047).

Conclusions:Brachiocephalic branch re-entry in patients with A-AAD is related to a patent false lumen in the aortic arch early after ascending aortic replacement and is a risk factor for late aortic arch enlargement.

Background:Glycated hemoglobin (HbA1c) is a suspected risk factor for sternal wound infection (SWI) after CABG.

Methods and Results:Data on preoperative HbA1c and SWI were available in 2,130 patients undergoing isolated CABG from the prospective E-CABG registry. SWI occurred in 114 (5.4%). Baseline HbA1c was significantly higher in patients with SWI (mean, 54±17 vs. 45±13 mmol/mol, P<0.0001). This difference was also observed in patients without a diagnosis of diabetes (P=0.027), in insulin-dependent diabetic (P=0.023) and non-insulin-dependent diabetic patients (P=0.034). In the overall series, HbA1c >70 mmol/mol (NGSP units, 8.6%) was associated with the highest risk of SWI (20.6% vs. 4.6%; adjusted OR, 5.01; 95% CI: 2.47–10.15). When dichotomized according to the cut-off 53 mmol/mol (NGSP units, 7.0%) as suggested both for diagnosis and optimal glycemic control of diabetes, HbA1c was associated with increased risk of SWI in the overall series (10.6% vs. 3.9%; adjusted OR, 2.09; 95% CI: 1.24–3.52), in diabetic patients (11.7% vs. 5.1%; adjusted OR, 2.69; 95% CI: 1.38–5.25), in patients undergoing elective surgery (9.9% vs. 2.7%; adjusted OR, 2.09; 95% CI: 1.24–3.52) and in patients with bilateral mammary artery grafts (13.7% vs. 4.8%; adjusted OR, 2.35; 95% CI: 1.17–4.69).

Conclusions:Screening for HbA1c before CABG may identify untreated diabetic patients, as well as diabetic patients with suboptimal glycemic control, at high risk of SWI.

Background:Nonischemic dilated cardiomyopathy (NIDCM) patients, even those with a narrow QRS, are at increased risk for major adverse cardiac events (MACE). We hypothesized that 64-channel magnetocardiography (MCG) would be useful to detect prognostic left intraventricular disorganized conduction (LiDC) by overcoming the limitations of fragmented QRS (fQRS, qualitative definitions, low specificity) and late potential (abnormality undetectable in earlier QRS).

Methods and Results:We evaluated LiDC on MCG, defined as significant deviation from a global clockwise left ventricular (LV) activation pattern, and conventional noninvasive predictors of MACE, including fQRS and late potential, in 51 NIDCM patients with narrow QRS (LV ejection fraction, 22±7%; QRS duration, 99±11 ms). MACE was defined as cardiac death, lethal ventricular arrhythmias, or LV assist device (LVAD) implantation. LiDC was present in 22 patients. Baseline characteristics were comparable between patients with and without LiDC, except for the ratio of positive late potential. During a mean follow-up of 2.9 years, MACE developed in 16 NIDCM patients (3 cardiac deaths, 9 lethal ventricular arrhythmias, and 4 LVAD). MACE was more incident in patients with LiDC (13/22) than in those without (3/29, P<0.001). Multivariate analysis revealed LiDC, but not fQRS or late potential, as the strongest independent predictor of MACE (hazard ratio 4.28, 95% confidence interval 1.30–19.39, P=0.015).

Conclusions:MCG accurately depicts LiDC, a promising noninvasive predictor of MACE in patients with NIDCM and normal QRS.

Background:Kynurenine is a circulating metabolite from the essential amino acid tryptophan. Accelerated degradation of kynurenine in skeletal muscle has been reported to provide an anti-inflammatory effect. The aim of this study was to investigate the association between blood kynurenine and muscle mass/function in patients with heart failure (HF), in whom diseased muscle mass/function plays a pathophysiological role.

Methods and Results:Plasma kynurenine was assessed in 249 patients with HF (67±11 years, 21% women) and in 45 controls from the SICA-HF study. Kynurenine was higher in 173 HF patients with reduced ejection fraction (EF) and in 76 patients with preserved EF than controls (3.5±1.5, 3.4±1.3, and 2.4±1.1 μmol/L, P<0.001). In HF patients, kynurenine had an inverse association with handgrip strength (r=–0.26, P<0.01), peak oxygen consumption (r=–0.29, P<0.01), 6-min walk distance (r=–0.23, P<0.01), and had a positive association with kidney and liver function parameters. No correlation was observed between kynurenine and lean mass. On multivariable linear regression analysis, a significant association was noted between kynurenine and peak oxygen consumption even after adjustment for age, gender, BMI, and hemoglobin (β=–0.23, P<0.001). Patients with higher kynurenine were at higher risk of death (adjusted HR, 1.46 per 1 μmol/L, P<0.01).

Conclusions:In stable HF patients, plasma kynurenine was inversely correlated with muscle strength and functional capacity as well as with liver and kidney function.

Background:Prolonged QRS duration (pQRSd) on electrocardiogram (ECG) is a strong predictor of poor outcome in heart failure, myocardial infarction, and myocarditis, but it is unclear whether pQRSd also predicts poor outcomes of takotsubo cardiomyopathy (TC).

Methods and Results:Between 1 January 2010 and 31 December 2012, we retrospectively enrolled 299 patients with TC (mean age, 73.5±11.7 years; 21.4% male) from the Tokyo CCU Network database, which consists of 71 cardiovascular centers in the metropolitan area. In-hospital clinical outcomes were compared between patients with pQRSd on admission ECG (QRS ≥120 ms; n=34) and those with normal QRS duration (<120 ms; n=265). The in-hospital mortality rate for pQRSd was significantly higher than that for normal QRS duration (23.5% vs. 3.8%, P<0.001). Similarly, prevalence of ventilator use (38.2% vs. 11.4%, P<0.001), ventricular tachycardia or fibrillation (14.7% vs. 1.5%, P<0.001), and circulatory failure requiring catecholamine or cardiopulmonary supportive devices (41.2% vs. 14.0%, P<0.001) was significantly higher in the pQRSd group. On multivariate logistic regression analysis, pQRSd was an independent predictor for both in-hospital mortality (OR, 5.06; 95% CI: 1.79–14.30, P=0.002) and cardiac death (OR, 7.34; 95% CI: 1.33–40.51, P=0.02).

Conclusions:TC with pQRSd is associated with poor in-hospital clinical outcome. Aggressive intervention may be required to prevent severe complications in these patients.

Background:Social background is important in preventing admission/readmission of heart failure (HF) patients. However, few clinical studies have been conducted to assess the social background of these patients, especially elderly patients.

Methods and Results:The Kitakawachi Clinical Background and Outcome of Heart Failure (KICKOFF) Registry is a prospective multicenter community-based cohort of HF patients, established in April 2015. We compared the clinical characteristics and social background of the super-elderly group (≥85 years old) and the non-super-elderly group (<85 years old). This study included 647 patients; 11.8% of the super-elderly patients were living alone, 15.6% were living with only a partner, and of these, only 66.7% had the support of other family members. The super-elderly group had less control over their diet and drug therapies than the non-super-elderly group. Most patients in the super-elderly group were registered for long-term care insurance (77.4%); 73.5% of the super-elderly patients could walk independently before admission, but only 55.5% could walk independently at discharge, whereas 94% of the non-super-elderly patients could walk independently before admission and 89.4% could walk independently at discharge.

Conclusions:The KICKOFF Registry provides unique detailed social background information of Japanese patients with HF. Super-elderly patients are at serious risk of social frailty; they need the support of other people and their ability to perform activities of daily living decline when hospitalized.

Background:Excess dietary salt is strongly correlated with cardiovascular disease, morbidity, and mortality. Conversely, potassium likely elicits favorable effects on cardiovascular disorders. In epidemiological studies, increased plasma osteoprotegerin (OPG) concentrations are associated with atherosclerosis and vascular deaths. Our study was designed to examine the effects of salt intake and potassium supplementation on plasma OPG levels in normotensive subjects.

Methods and Results:The 18 normotensive subjects were selected from a rural community in China. They were sequentially maintained on low-salt diet for 7 days (3 g/day, NaCl), high-salt diet for 7 days (18 g/day), and high-salt diet with potassium supplementation for 7 days (18 g/day of NaCl+4.5 g/day of KCl). High-salt intake enhanced plasma OPG levels (252.7±13.9 vs. 293.4±16.1 pg/mL). This phenomenon was abolished through potassium supplementation (293.4±16.1 vs. 235.1±11.3 pg/mL). Further analyses revealed that the OPG concentration positively correlated with 24-h urinary sodium excretion (r=0.497, P<0.01). By contrast, OPG concentration negatively correlated with 24-h urinary potassium excretion (r=0.594, P<0.01).

Conclusions:Salt loading can enhance the production of circulating OPG. Potassium supplementation can reverse the effects of excessive OPG. Our study results may improve our understanding of the roles of salt and potassium in the risk of cardiovascular disorders.

Background:No study has evaluated the clinical consequences of stent fracture (SF) detected during the index percutaneous coronary intervention (PCI). Thus, we sought to investigate the relationship between SF detected during PCI and clinical outcome.

Methods and Results:We consecutively enrolled 832 patients with SF-predisposing factors undergoing 2nd-generation drug-eluting stent implantation and enhanced stent visualization (ESV) system evaluation to detect SF at index PCI. The primary endpoint was a 9-month device-oriented endpoint (DOCE, including cardiac death, target vessel myocardial infarction, and target lesion revascularization). We observed 136 SF in 115 patients (14% of study population). SF I–II was present in 78 patients (68% of patients with SF), and SF III–IV occurred in 37 patients (32%). DOCE at 9 months occurred in 135 patients (16% of the overall population). There was a significant difference in DOCE occurrence between the 3 groups (P=0.006 at log-rank), driven by the SF III–IV group (P=0.001 vs. no SF group, and P=0.01 vs. SF I–II group). In 23 cases of SF III–IV (62%) a further stent was implanted. DOCE occurrence was significantly higher in patients with “untreated” type III–IV SF as compared with the “treated” ones (9% vs. 79%, P<0.01).

Conclusions:The ESV system is helpful in detecting SF during the index PCI. Type III–IV SFs are associated with a higher incidence of DOCE.

Background:High-sensitivity C-reactive protein (hs-CRP) has been used to predict the risk of adverse cardiac events in patients with coronary artery disease (CAD) after percutaneous coronary intervention (PCI). Less is known, however, about the association between hs-CRP and long-term outcome after PCI in the Japanese population.

Methods and Results:We studied 3,039 all-comer patients with CAD who underwent their first PCI and had data available for preprocedural hs-CRP at Juntendo University between 2000 and 2011. Patients were assigned to tertiles based on preprocedural hs-CRP concentration. We evaluated the incidence of major adverse cardiac events (MACE) including all-cause death, acute coronary syndrome (ACS), and target vessel revascularization (TVR). Patients with higher hs-CRP had a higher prevalence of current smoking, chronic kidney disease and ACS, and a lower prevalence of statin use. During a median follow-up period of 6.5 years, ongoing divergence in MACE with hs-CRP tertile was noted on Kaplan-Meier curves (hs-CRP <0.08 mg/L, 26.4%; 0.08–0.25 mg/L, 38.2%; >0.25 mg/L, 45.6%; log-rank P<0.001). After adjustment for established cardiovascular risk factors, hs-CRP was associated with higher incidence of MACE (hazard ratio [HR], 1.10; 95% CI: 1.04–1.16, P<0.001) and higher all-cause mortality (HR, 1.14; 95% CI: 1.06–1.22, P<0.001).

Conclusions:Preprocedural hs-CRP measurement is clinically useful for long-term risk assessment in Japanese patients with established CAD and undergoing PCI.

Background:Coronary spastic angina (CSA) is common among East Asians and tobacco smoking (TS) is an established risk factor for CSA. Aldehyde dehydrogenase 2 (ALDH2) plays a key role in removing reactive toxic aldehydes and a deficient variant ALDH2 genotype (ALDH2*2) is prevalent among East Asians. We examined the interaction between TS andALDH2*2as a risk factor for CSA to better understand the disease pathogenesis.

Methods and Results:The study subjects comprised 410 patients (258 men, 152 women; mean age, 66.3±11.5) in whom intracoronary injection of acetylcholine was performed on suspicion of CSA.ALDH2genotyping was performed by direct application of the Taqman polymerase chain reaction system. Of the study subjects, 244 had CSA proven and 166 were non-CSA. The frequencies of male sex,ALDH2*2, alcohol flushing syndrome, TS, coronary organic stenosis, and plasma levels of uric acid were higher (P<0.001, P<0.001, P<0.001, P<0.001, P<0.001, and P=0.015, respectively) and that of high-density lipoprotein cholesterol lower (P=0.002) in the CSA than non-CSA group. Multivariable logistic regression analysis revealed thatALDH2*2and TS were significant risk factors for CSA (P<0.001 and P=0.002, respectively).ALDH2*2exacerbated TS risk for CSA more than the multiplicative effects of each.

Conclusions:ALDH2*2synergistically exacerbates TS risk for CSA, probably through aldehydes.

Background:Very limited data exist on the outcomes of transcatheter aortic valve implantation (TAVI) since Japanese marketing approval of the first TAVI device.

Methods and Results:The Kyoto University-related hospital Transcatheter Aortic Valve Implantation (K-TAVI) registry includes prospectively collected data from 6 participating hospitals in Japan. We included 302 patients with severe aortic stenosis who underwent TAVI using the SAPIEN XT balloon-expandable valve via transfemoral (TF; n=203, 67%) or transapical (TA; n=99, 33%) approach between October 2013 and September 2015. Device success rate, based on the Valve Academic Research Consortium-2 criteria, was very high in the TF (97.0%) and TA (99.0%) groups. The 30-day mortality rates were 1.5% and 1.0% in the TF and TA groups, respectively. Major complications included stroke (transient or persistent: 2.3%), annulus rupture (1.0%), coronary intervention (1.0%), major vascular complications (1.7%), and permanent pacemaker implantation (5.4%). The procedure times of the post-proctoring period (n=210) were decreased compared with those of the proctoring period (n=89) without affecting the clinical outcomes. The survival rates at 6 and 12 months were 96.9% and 92.5% in the TF group, and 93.9% and 91.8% in the TA group, respectively.

Conclusions:The K-TAVI registry data revealed that the early outcomes of TAVI using the SAPIEN XT were favorable in real-world Japanese patients.

Background:Approximately 10–20% of Kawasaki disease (KD) patients are resistant to intravenous immunoglobulin (IVIG) treatment. Further, these patients are at a particularly high risk of having coronary artery abnormalities. The mechanisms of IVIG resistance in KD have been analyzed using patient leukocytes, but not patient vascular endothelial cells (ECs). The present study clarifies the mechanisms of IVIG resistance in KD using an induced pluripotent stem cell (iPSC) disease model.

Methods and Results:Dermal fibroblasts or peripheral blood mononuclear cells from 2 IVIG-resistant and 2 IVIG-responsive KD patients were reprogrammed by the episomal vector-mediated transduction of 6 reprogramming factors. KD patient-derived iPSCs were differentiated into ECs (iPSC-ECs). The gene expression profiles of iPSC-ECs generated from IVIG-resistant and IVIG-responsive KD patients were compared by RNA-sequencing analyses. We found that the expression ofCXCL12was significantly upregulated in iPSC-ECs from IVIG-resistant KD patients. Additionally, Gene Set Enrichment Analysis (GSEA) revealed that gene sets involved in interleukin (IL)-6 signaling were also upregulated.

Conclusions:The first iPSC-based model for KD is reported here. Our mechanistic analyses suggest thatCXCL12, which plays a role in leukocyte transmigration, is a key molecule candidate for IVIG resistance and KD severity. They also indicate that an upregulation of IL-6-related genes may be involved in this pathogenesis.