P6283Downregulation of Tim44 exacerbates oxidative stress-induced ROS production and cardiomyocytes death by reducing mitochondrial SOD2

Background

Mitochondrial dysfunction has been highlighted as a critical driver of cardiac remodeling and failure. Mitochondria contains about 1500 proteins, 99% of which are encoded in the nuclear genome. Therefore, protein import into mitochondria is essential to maintain mitochondrial function. Previous reports suggest that nuclear-encoded mitochondrial precursor proteins import into mitochondria by multiple complex; translocase of outer membrane (TOM), translocase of inner membrane (TIM), and protein associated motor (PAM). However, the role of these protein import machineries of mitochondria in cardiac remodeling remains to be elucidated.

Objective

The purpose of this study was to elucidate the role of TOM, TIM, and PAM complex in cardiac remodeling and cardiomyocyte death.

Methods and results

C57BL/6J mice were subjected to myocardial infarction (MI) by permanent ligation of left anterior descending artery. Four weeks after operation, MI-mice demonstrated left ventricular (LV) dilation (LV end-diastolic dimension: 3.91 vs. 5.54 mm, n=8–11, p<0.05) and dysfunction (LV fractional shortening: 33.3 vs. 7.7%, n=8–11, p<0.05). Tim44 protein levels, a component of PAM complex, in mitochondrial fraction from non-infarcted left ventricle were significantly decreased compared with those in the heart from sham-operated mice by 39% (p<0.05), whereas other proteins related to TOM, TIM and PAM complex such as Tom20, Tom22, Tom40, Tom70, Tim22, Tim23 and mtHSP70 were not altered between MI-mice and sham-mice. In addition, blue-native polyacrylamide gel electrophoresis revealed that a protein complex associated to Tim44 was significantly decreased in non-infarcted LV by 40% (p<0.05). Superoxide dismutase 2 (SOD2), a mitochondrial matrix protein, was decreased in mitochondrial fraction from non-infarcted LV by 20% (p<0.05), accompanied by enhancing protein carbonylation, a marker of oxidative stress, by 40% (p<0.05). To assess the role of Tim44, it was downregulated by small interfering RNA in cultured neonatal rat ventricular myocytes (NRVMs). Knockdown of Tim44 significantly decreased SOD2 protein levels in mitochondrial fractionation (22%, p<0.05), with no significant changes in its mRNA levels. Furthermore, knockdown of Tim44 significantly increased protein carbonylation (20%, p<0.05) and cleaved caspase 3 (47%, p<0.05) and decreased cell viability (69%, p<0.05), assessed by cell titer assay, in H2O2-treatred NRVMs.

Conclusions

Downregulation of Tim44 exacerbates oxidative stress-induced ROS production and cardiomyocytes death, which is associated with a decrease in mitochondrial SOD2. Endogenous Tim44 might play a protective role in cardiac remodeling by attenuating oxidative stress and cardiomyocyte death via SOD2 import into mitochondria.

P3771Validation of risk scoring system predicting for progression of atrial fibrillation: the Fushimi AF Registry

Background

Atrial fibrillation (AF) increases the risks of thromboembolism and death. Progression from paroxysmal to sustained types (persistent or permanent) of AF is sometimes seen in clinical practice. We recently reported that progression of AF was associated with increased risk of clinical adverse events in Japanese AF patients. However, risk stratification schemes of predicting the progression of AF has not been fully established.

Methods

The Fushimi AF Registry, a community-based prospective survey, was designed to enroll all of the AF patients in Fushimi-ku, Kyoto, which is a typical urban district of Japan with a population of 283,000. Follow-up data were available for 4,454 patients. We investigated the risk factors of AF progression and validated the performance of various risk scoring systems predicting for progression of AF, such as APPLE, BASE-AF2, HATCH, and MB-LATER score, using data from 995 paroxysmal AF patients (mean age; 72.6±11.4 years, female; 42.2%, mean CHA2DS2-VASc score; 3.26±1.67) whose echocardiogram data were obtained at baseline.

Results

Of 995 AF patients, during the median follow-up of 1,477 days, progression from paroxysmal to sustained AF occurred in 160 patients (16.1%; 4.0 per 100 person-years). On a multivariate model, we indicated that history of AF ≥2 years (odds ratio [OR] 1.83; 95% confidence interval [CI] 1.28–2.61), left atrial diameter ≥40 mm (OR 1.45; 95% CI 1.02–2.08), daily drinker (OR 1.56; 95% CI 1.24–2.81), and cardiomyopathy (OR 2.58; 95% CI 1.17–5.69) were significantly associated with higher incidence of AF progression. Our model had better predictive potential for AF progression (area under curve [AUC] 0.612; 95% CI 0.566–0.658) than the APPLE (AUC 0.553; 95% CI 0.508–0.598; p=0.06), BASE-AF2 (AUC 0.571; 95% CI 0.526–0.617; p=0.04), CHADS2 (AUC 0.508; 95% CI 0.462–0.554; p<0.01), CHA2DS2-VASc (AUC 0.501; 95% CI 0.453–0.548; p<0.01), HATCH (AUC 0.502; 95% CI 0.456–0.548; p<0.01), and MB-LATER (AUC 0.528; 95% CI 0.483–0.572; p<0.01) score.

Conclusion

We identified 4 risk factors which may be useful to predict for progression of AF in Japanese patients. External validation of our model in other cohorts is needed.

Acknowledgement/Funding

Boehringer, Bayer, Pfizer, Bristol-Myers, Astellas, AstraZeneca, Daiichi Sankyo, Novartis, MSD, Sanofi and Takeda. Japan Agency for Medical Research

P1606Glutamine-fructose-6-phosphate amidotransferase 2 mediates isoproterenol-induced cardiac hypertrophy by increasing Akt O-GlcNAcylation through hexosamine biosynthesis pathway

Background

Cardiac hypertrophy is an independent risk factor for heart failure and cardiac death. Hexosamine biosynthesis pathway (HBP), an accessory pathways of glycolysis, is known to be involved in the attachment of O-linked N-acetylglucosamine motif (O-GlcNAcylation) to proteins, a post-translational modification. However, the role of HBP has not been determined in pathological cardiac hypertrophy.

Purpose

The purpose of this study to examine whether glutamine-fructose-6-phosphate amidotransferase 2 (GFAT2), a critical enzyme of HBP, mediates cardiac hypertrophy by protein O-GlcNAcylation and activating hypertrophic signaling in cardiomyocytes.

Methods and results

C57BL/6J mice were treated with isoproterenol (ISO: 15 mg/kg/day, 1 week) with or without 6-Diazo-5-oxo-L-norleucine (DON, an inhibitor of GFAT: 500 μg/kg/day, 1week). ISO-treated mice (ISO+vehicle) showed cardiac hypertrophy, which were attenuated in ISO and DON-treated mice (ISO+DON) (heart weight to tibial length ratio: 7.70±0.09 vs. 7.11±0.15 mg/mm, n=12, p<0.05, left ventricular wall thickness: 1.05±0.02 vs. 0.86±0.03 mm, n=6, p<0.05). Cardiomyocyte cross-sectional area was also decreased in ISO+DON compared with ISO+vehicle (309±25 vs. 252±13 mm2, n=,3 p<0.05). Whereas expression levels of GFAT2 and protein O-GlcNAcylation in the heart were increased in ISO+vehicle compared with control+vehicle by 3.3 and 1.5 folds, respectively (n=9 and n=9, p<0.05), expression levels of O-GlcNAc transferase (OGT) and the β-N-acetylglucosaminidase (OGA), other enzymes regulating O-GlcNAcylation, were not altered in both groups, indicating that ISO activated HBP by GFAT2. Protein O-GlcNAcylation in ISO+DON was lower than that in ISO+vehicle by 83% (n=9, p<0.05). In addition, phosphorylation of Akt, a critical mediator of cardiac hypertrophy, but not other mediators of cardiac hypertrophy such as ERK, JNK, or p38MAPK, was significantly decreased in ISO+DON by 76% (n=9, p<0.05). In cultured neonatal rat ventricular myocytes, treatment with ISO (1μM, 12h) increased the expression levels of GFAT2 and protein O-GlcNAcylation by 1.3 and 1.5 folds, respectively (n=6 and n=6, p<0.05), but not GFAT1. Furthermore, ISO stimulation increased a direct O-GlcNAcylation of Akt by 1.4 folds (n=3, p<0.05). Downregulation of GFAT2 by RNA silencing decreased cell size by 82% (n=6, p<0.05) and protein O-GlcNAcylation and phosphorylation of Akt by 76% and 54%, respectively (n=9 and n=9, p<0.05) in cardiomyocyte treated with ISO. Conversely, administration of glucosamine, a substrate of HBP, increased protein of O-GlcNAcylation and phosphorylation of Akt by 1.3 and 1.8 folds, respectively (n=6 and n=6, p<0.05).

Conclusions

GFAT2, a limiting enzyme of HBP, mediates pathological cardiac hypertrophy by Akt activation probably due to its O-GlcNAcylation. GFAT2-O-GlcNAcylation-Akt pathway might be a potential novel therapeutic target for cardiac hypertrophy.

P6405Potential for drug-drug interaction between vonoprazan and prasugrel on antiplatelet effect assessed by VerifyNow P2Y12 assay in patients with coronary artery disease

Background

Vonoprazan is a potassium-competitive acid blocker increasingly used in Japan to prevent gastrointestinal bleeding in patients under dual antiplatelet therapy (DAPT) after coronary stents implantation. Since cytochrome P450 (CYP) 3A4 is involved in the primary metabolism of vonoprazan and prasugurel, there is a possibility that CYP-mediated drug-drug interaction between them can attenuate the antiplatelet function of prasugrel.

Purpose

The aim of this study was to investigate whether antiplatelet effect of prasugrel could be attenuated upon coadministration with vonoprazan compared to conventional proton pump inhibitors (PPIs).

Method

We evaluated 72 patients (57 males, 67±11 years) with coronary artery disease who were taking either vonoprazan (n=35) or PPIs (n=37) in combination with DAPT (aspirin and prasugrel) after drug-eluting stents implantation. PPIs included 21 esomeprazole, 8 lansoprazole, and 8 rabeprazole. Antiplatelet effects of prasugrel were assessed using VerifyNow P2Y12 assay. Primary measurements were P2Y12 reaction units (PRU) and P2Y12 percent inhibition. High on-treatment platelet reactivity (HPR) on prasugrel was defined as PRU >208. Administration period of vonoprazan or PPIs in combination with DAPT ≤7 days was defined as early administration period.

Results

Median administration period of vonoprazan or PPIs in combination with DAPT was 127 days. There were no significant differences in baseline clinical characteristics between patients with vonoprazan and PPIs. In the analysis for all subjects, patients with vonoprazan showed similar PRU (166±50 vs. 167±64, p=0.93) and percent inhibition (36±18 vs. 38±23, p=0.66) compared to those with PPIs. No significant differences were observed in the prevalence of HPR between patients with vonoprazan and PPIs (17 vs. 30%, p=0.27). In the analysis for patients in early administration period [vonoprazan (n=14) vs. PPIs (n=10)], there were no significant differences in PRU (166±47 vs. 186±82, p=0.45), percent inhibition (33±17 vs. 30±26, p=0.73), and prevalence of HPR (14 vs. 50%, p=0.085) between patients with vonoprazan and PPIs. In addition, the analysis for patients over early administration period [vonoprazan (n=21) vs. PPIs (n=27)] showed that PRU (166±55 vs. 160±57, p=0.73), percent inhibition (37±19 vs. 41±21, p=0.57), and prevalence of HPR (19 vs. 22%, p=1.00) were comparable between patients with vonoprazan and PPIs.

Conclusion

Compared to PPIs, vonoprazan did not exhibit significant inhibitory effects on the antiplatelet activity of prasugrel assessed by VerifyNow assay. These findings suggest that there are possibly no clinically harmful drug-drug interactions between vonoprazan and prasugrel.

P3575Clinical importance of fractional flow reserve in patients with organic coronary stenosis and vasospastic angina

Background

Vasospastic angina (VSA), which is one of the important functional cardiac disorders, may also play a role in the pathogenesis of atherosclerosis. Conversely, organic coronary stenosis is also known as an independent predictor for poor clinical outcomes in VSA patients. Although VSA patients have a variable degree of organic coronary stenosis in clinical setting, the functional importance of organic stenosis in those patients remains to be elucidated.

Purpose

The aim of this study was to examine the clinical importance and prognostic impact of fractional flow reserve (FFR) in patients with VSA and organic coronary stenosis.

Methods

We enrolled 236 consecutive patients with suspected vasospastic angina who underwent acetylcholine provocation test for coronary spasm (M/F 148/88, 63.6±12.0 [SD] yrs.). Among them, 175 patients (74.1%) were diagnosed as having VSA, while the remaining non-VSA patients were regarded as controls (Group-C, n=61). We divided the VSA patients into 3 groups based on angiographical findings and FFR values; VSA with no organic stenosis (>50% luminal stenosis) (Group-N, n=110), organic stenosis and high FFR (≥0.80) (Group-H, FFR 0.87±0.05, n=36), and organic stenosis and low FFR (<0.80) (Group-L, FFR 0.71±0.07, n=29). We evaluated the incidence of major adverse cardiovascular events (MACE), including cardiovascular death (CVD), non-fatal myocardial infarction (MI), urgent percutaneous coronary intervention (PCI), and hospitalization due to unstable angina pectoris (UAP) during the median follow-up period of 656 days.

Results

The groups with organic stenosis (Groups H and L) were characterized by higher prevalence of diabetes mellitus (Group-C/N/H/L, 23.0/20.9/44.4/34.5%, P=0.03) and dyslipidemia (Group-C/N/H/L, 37.7/39.1/50.0/65.5%, P=0.03) as compared with Group-C. After provocation test, all VSA patients received calcium channel blockers (CCBs). In addition, 20 days (median) after provocation test, 26 patients (92.9%) in Group-L underwent elective PCI with coronary stents, while no patient underwent PCI in Groups N or H. The incidence of MACE during follow-up was significantly higher in Group-L (Group-C/N/H/L; 1.6/3.6/5.6/27.6%, log-rank P<0.001), whereas clinical outcomes were comparable among the remaining 3 groups (Figure). Importantly, all 8 patients with MACE in Group-L had poor outcomes (CVD/MI/urgent PCI/UAP; 2/1/3/2) despite complete revascularization and the prevention of coronary spasm with CCBs, indicating that they might be resistant to standard contemporary therapies. They were characterized by less frequent use of angiotensin convert enzyme inhibitor (0 vs. 47.6%, P=0.02) and higher prevalence of multi-vessel organic lesions (37.5 vs. 4.8%, P=0.052) compared with those without MACE.

Figure 1

Conclusions

These results provide the first evidence that evaluation of coronary functional abnormalities with FFR is useful for making therapeutic strategies in VSA patients with organic coronary stenosis.

P6305Activation of invariant natural killer T cells ameliorates doxorubicin-induced cardiomyopathy

Background

Invariant natural killer T (iNKT) cells orchestrate tissue inflammation via regulating various cytokine productions, especially strongly upregulating interferon (IFN)-γ. Activation of iNKT cells have been previously reported to exert protective effects against post-infarcted cardiac remodeling and cardiac ischemia/reperfusion injury. However, the role of iNKT cells has not been determined in doxorubicin (DOX)-induced cardiomyopathy.

Purpose

The purpose of this study was to examine whether the activation of iNKT cells by α-galactosylceramide (αGC), which specifically activates iNKT cells, could affect DOX-induced cardiomyopathy, and if so, to elucidate its downstream target.

Methods

C57BL/6J mice were received the intraperitoneal injection of either αGC (0.1μg/g, n=11) or vehicle (n=13). After 1 week, these mice were treated with a low dose of DOX (18mg/kg via intravenous 3 injections over 1 week), and were followed during 14 days.

Results

DOX mice (DOX+vehicle) showed left ventricular (LV) dysfunction and dilatation, which were significantly ameliorated in DOX mice receiving αGC (DOX+αGC) (LV fractional shortening: 27.4±4.31 vs. 31.5±4.62%, p<0.05, LV end-diastolic diameter: 3.70±0.16 vs. 3.32±0.23mm, p<0.05), with no significant changes in arterial pressure, body weight, and food consumption, 14 days after DOX injection. DOX+vehicle demonstrated a significant decrease in myocardial gene expression of Vα14Jα18, a specific marker of iNKT cells, and IFN-γ compared with control mice. Vα14Jα18 expression levels were higher in DOX+αGC than DOX+vehicle by 9.2 folds (p<0.05). Consistent with this change, IFN-γ was higher in DOX+αGC than DOX+vehicle by 4.4 folds (p<0.05), whereas interleukin (IL)-1, IL-4, IL-6, IL-10, IL-17, IL-23, and tumor necrosis factor (TNF)-α were not altered in both groups. Phosphorylation of Akt, its active form, in the heart was significantly increased in DOX+αGC compared with DOX+vehicle by 1.8 folds (p<0.05).

Conclusions

Activation of iNKT cells by αGC play a protective role against DOX-induced cardiac dysfunction, which was associated with enhancing expression of IFN-γ and activating Akt. Therapies designed to activate iNKT cells might be beneficial to protect the heart from DOX injury.

P4158Marked impairment of endothelium-dependent digital vasodilatations in patients with microvascular angina compared with those with vasospastic angina

Background/Introduction

Nitric oxide (NO) and endothelium-dependent hyperpolarization (EDH) factor are the major endothelium-derived relaxing factors. NO plays an important role in conduit arteries, while the importance of EDH factor increases as the vessel size decrease in patients with microvascular angina (MVA) compared with those with vasospastic angina (VSA) remains to be fully elucidated.

Purpose

We evaluated the roles of NO and EDH factor in conduit (brachial) arteries and resistance (digital) arteries of the patients with MVA, VSA and comorbid MVA+VSA patients.

Methods

We enrolled 39 patients who underwent diagnostic cardiac catheterization and divided them into 3 groups based on acetylcholine (ACh) provocation test, index of microcirculation resistance (IMR), and coronary flow reserve (CFR); MVA (N=9, mean age 59.9±3.5 years), VSA (N=12, mean age 61.3±1.8 years), and comorbid MVA+VSA (N=18, mean age 64.0±2.2 years). Endothelium-dependent brachial and digital vasodilatations in response to intra-arterial infusion of bradykinin (BK, 25, 50, and 100 ng/min for 2 min) were simultaneously measured by ultrasonography and peripheral arterial tonometry, respectively. Measurements were repeated after oral administration of aspirin (486 mg) and intra-arterial infusion of NG-monomethyl-L-arginine (L-NMMA, 8μmol/min for 5 min) in order to inhibit the effects of vasodilator prostaglandins and NO, respectively. Finally, endothelium-independent brachial and digital vasodilatations in response to sublingual nitroglycerin (NTG, 0.3 mg) were measured in the same manner.

Results

In the brachial artery, dose-dependent vasodilatations to BK were comparable among the 3 groups, and L-NMMA equally attenuated the responses to BK (Figure 1). Endothelium-independent brachial vasodilatation in response to NTG was also comparable among the 3 groups. Surprisingly, dose-dependent digital vasodilatations to BK were almost absent in MVA patients compared with VSA or comorbid MVA+VSA group (Figure 2). Furthermore, the digital vasodilatations were unaffected by L-NMMA in VSA group, but were significantly reduced in comorbid MVA+VSA group (VSA, 16.8±15.1% vs. MVA+VSA, −0.23±6.2%, P<0.05), suggesting reduced EDH and compensatory role of NO in the latter group. In contrast, endothelium-independent digital vasodilatation in response to NTG was comparable among the 3 groups.

The main results of this study

Conclusions

These results provide the first evidence that endothelium-dependent digital vasodilatations (both NO and EDH factor) are markedly impaired in MVA patients compared with VSA or comorbid MVA+VSA patients, whereas the responses are comparable in the brachial artery among the 3 groups, suggesting the involvement of severe endothelial dysfunction in the pathogenesis of MVA.

P1549Serum soluble Klotho is associated with extent of coronary artery calcification in patients with stable angina pectoris undergoing percutaneous coronary intervention

Background

Klotho, which was originally identified as an aging suppressor, is a key regulator of bone and mineral metabolism. Transmembrane and soluble forms of Klotho protein have been identified. The transmembrane form serves as an obligate co-receptor for fibroblast growth factor 23 (FGF23). However, the physiological importance of soluble form of Klotho has not been determined.

Purpose

The present study aimed to test the hypothesis that circulating soluble Klotho levels can predict the presence or extent of coronary artery calcification (CAC) in patients with coronary artery disease.

Methods

We analyzed CAC of culprit lesions in patients with 75 stable angina pectoris who were not on dialysis and were scheduled for percutaneous coronary intervention (PCI) following intravascular ultrasound (IVUS). Arc and length of each calcium within the culprit lesion was measured by IVUS. The main outcome measure was the calcium index; a volumetric IVUS-derived measure which was calculated as total calcium length/lesion length × maximal calcium arc/360°. Low calcium index was defined as calcium index <0.042 of the first quartile value. Serum Klotho and FGF23 were measured before PCI. Patients were divided into two groups according to median serum Klotho value: low-Klotho (n=37, ≤460 pg/mL) and high-Klotho group (n=38, >460 pg/mL).

Results

Compared with patients with low-Klotho, those with high-Klotho had higher estimated glomerular filtration rate (eGFR) (69±20 vs. 55±16 mL/min/1.73 m2, p<0.001), lower FGF23 levels (51±24 vs. 67±41 pg/mL, p=0.010). Patients with high-Klotho had significantly lower calcium index than those with low-Klotho (0.17±0.21 vs. 0.24±0.23, p=0.043). Serum Klotho levels correlated significantly and inversely with calcium index (r=−0.31, p=0.006). The correlation between Klotho and calcium index was pronounced at analysis in patients with eGFR <60 mL/min/1.73 m2 (r=−0.52, p<0.001). Logistic regression analysis showed that high-Klotho is a sole significant independent factor associated with low calcium index (odds ratio 7.17, p=0.004). Presence of high-Klotho had high sensitivity and negative predictive value for identifying low calcium index (83% and 92%, respectively).

Conclusions

Serum Klotho values were independently and inversely associated with the degree of CAC assessed by IVUS. These findings have important clinical implications for serum Klotho as a biomarker that reflects the extent of CAC.

P3764Morphological mechanisms of atrial functional mitral regurgitation in patients with atrial fibrillation

Background

Atrial functional mitral regurgitation (AFMR) occurs in patients with atrial fibrillation. However, morphological mechanisms of AFMR are poorly understood.

Purpose

The purpose of this study was to examine the morphological characteristics in patients with AFMR.

Methods

Among consecutive 795 patients undergoing initial radiofrequency catheter ablation (RFCA) at our hospital, twenty-five patients with persistent AF accompanied by AFMR (≥ moderate) before RFCA (AFMR group) were studied. Age-matched 25 patients with persistent AF without MR were defined as a control group.

Results

Left ventricular ejection fraction (LVEF) was lower and left atrium volume index was larger in the AFMR group (Table). Mitral valve annulus diameter and length of anterior mitral leaflet (AML) were similar between groups, whereas length of posterior mitral leaflet (PML) was significantly shorter in the AFMR group. Smaller tethering angle of AML (γ in the figure) and shorter tethering height were significantly associated with the occurrence of AFMR, which were different from morphology of functional mitral regurgitation in patients with dilated LV. Multiple regression analysis revealed that less tenting height (p<0.05) and LA dilatation toward the posterior (p<0.01) were significantly related to AFMR.

Echocardiographic parameters AFMR (n=25) Control (n=25) P value Age, y 69±8 66±10 NS Male, n (%) 9 (36) 20 (80) P=0.001 LVEF,% 60±9 67±6 P=0.004 LAD, mm 44±5 41±7 NS LAVI, ml/m2 56±17 41±13 P<0.001 MV diameter, mm 3.9±0.4 3.8±0.5 NS α angle, ° 34±9 35±7 NS β angle, ° 48±9 50±8 NS γ angle, ° 32±5 37±5 P=0.0005 AML length, mm 3.0±0.5 3.0±0.5 NS PML length, mm 2.1±0.1 2.4±0.1 P=0.03 Tenting height, mm 1.5±0.1 1.8±0.1 P=0.02 D, mm 0.8±0.3 0.5±0.3 P=0.001 LVEF: left ventricular ejection fraction; LAD: left atrial diameter; LAVI: left atrial volume index; AML: anterior mitral leaflet; PML: posterior mitral leaftlet.

Conclusions

AFMR occurs in patients with unique morphological features, such as less tethering height and LA dilatation toward the posterior.

P1025Clinical predictors for the improvement of left ventricular ejection fraction and prognosis after catheter ablation of atrial fibrillation in patients with systolic dysfunction

Background

Catheter ablation (CA) of atrial fibrillation (AF) improves left ventricular ejection fraction (LVEF) and clinical outcomes in patients with left ventricular systolic dysfunction (LVSD). However, predictors of the improvement of LV function and clinical outcomes by CA were poorly understood.

Purpose

We examined the efficacy of CA in AF patients with LVSD and predictive factors associated with clinical outcomes.

Method

Among consecutive 795 patients undergone initial RFCA at our hospital, we studied 51 patients with LVSD (LVEF ≤50%). Improved LVEF more then 5% at 1-year after CA was classified as “responder” to CA. We analyzed clinical variables and echocardiographic parameters before and after the CAs.

Results

In the responder group, LVEF was significantly improved 1-year after catheter ablation compared with the non-responder group. (ΔLVEF 22±12% vs. −1±4%, p<0.001). The responder group was significantly younger, had more non-paroxysmal AF, smaller LV systolic diameter and lower plasma BNP level before CA (Table). Late gadolinium enhancement (LGE)-positive rate in cardiovascular magnetic resonance imaging (CMR) before CA was higher in the non-responder group than in the responder group (100% [6/6] vs. 38% [5/13], p<0.005). After CAs of AF, event-free survival from hospitalization for heart failure was significantly higher in the responder group (Figure) with less AF recurrence (27% vs. 47%, p=0.04) than in the non-responder group.

Baseline characteristics Responder (N=35) Non-Responder (N=16) P value Age, y 62±11 69±8 p<0.01 Male, n (%) 26 (74) 13 (76) NS Non-pAF 26 (74) 4 (24) p<0.01 LAD, mm 48±7 48±8 NS LAVI, ml/m2 54±17 58±20 NS LVDd, mm 54±7 58±10 NS LVDs, mm 43±7 48±10 p=0.05 EF, % 37±8 38±8 NS BNP (pg/ml) 278±225 684±848 p<0.05

Conclusion

Younger age, absence of LV dilatation, lower plasma BNP, or absence of LGE may well predict favorable clinical outcomes after CA in patients with LVSD.

2381Low-intensity pulsed ultrasound ameliorates DES-induced coronary adventitial inflammation and hyperconstricting responses in pigs in vivo - A novel non-invasive therapy for coronary inflammation

Background

We previously demonstrated that coronary adventitial inflammation plays important roles in the pathogenesis of coronary artery spasm, including drug-eluting stent (DES)-induced coronary hyperconstricting responses, in pigs and humans. Indeed, the coronary adventitia has recently attracted much attention as the important site for vascular inflammation. However, a direct therapeutic approach to the coronary adventitia remains to be developed. We have developed a non-invasive low-intensity pulsed ultrasound (LIPUS) therapy for angina, which exerts anti-inflammatory effects through improved coronary microcirculation.

Purpose

In this study, we aimed to examine whether our LIPUS therapy ameliorates DES-induced coronary hyperconstricting responses in pigs in vivo, and if so, what mechanisms are involved.

Methods

An everolimus-eluting stent (EES) was implanted into the left anterior descending (LAD) coronary artery in normal male pigs. They were randomly assigned to the LIPUS or the sham therapy groups. After EES implantation, in the LIPUS group, LIPUS (32 cycles, 193 mW/cm2) was applied to the heart at 3 different levels (proximal and distal stent edges and middle portion of the stent) through X-ray for 20 min at each level for every other day for 2 weeks (6 days in total) (Figs. 1A, 1B). The sham therapy group was treated in the same manner but without LIPUS. At 4 weeks after the procedure, we performed coronary angiography to examine coronary vasoconstricting responses to intracoronary serotonin in vivo. Finally, stented coronary vessels were harvested for immunohistochemistry of vasa vasorum, lymphatic vessels (LYVE-1), sympathetic nerve fibers (SNF), vascular inflammation (macrophages and IL-1β expression), Rho-kinase expression and activity as evaluated by phosphorylated myosin phosphatase target subunit-1 (pMYPT-1).

Results

Coronary vasoconstricting responses to intracoronary serotonin were significantly enhanced in the sham therapy group but were significantly suppressed in the LIPUS group at the DES edges in the LAD, whereas those responses were comparable at the non-DES implanted segments in the left circumflex (LCx) coronary arteries between the 2 groups. (Figs. 1C, 1D). Furthermore, in vivo lymph transport speed was significantly faster in the LIPUS group than in sham group (Figs. 1E–1G). Histological analysis showed that except vasa vasorum formation, the number of lymphatic vessels, adventitial inflammatory cells infiltration, Rho-kinase expression and activity were all significantly enhanced in the sham therapy group and were significantly suppressed in the LIPUS group (Figs. 1G–1K).

Figure 1

Conclusion

We were able to develop a non-invasive LIPUS therapy for coronary functional abnormalities caused by chronic adventitial inflammation in pigs in vivo, for which multiple beneficial effects appear to be involved (Fig. 1L).

3332Exercise training ameliorates vasodilator capacity of coronary microvessels in patients with vasospastic angina - A new therapeutic approach for the coronary functional disorder

Background

We have recently demonstrated that coronary vasospasm could develop in both epicardial coronary arteries and intramuscular coronary microvessels in patients with vasospastic angina (VSA). However, it remains to be examined whether vasodilator capacity of coronary microvessels is impaired in VSA patients and if so, whether exercise training could ameliorate vasodilator capacity of coronary microvessels on the top of calcium channel blockers. The effectiveness of exercise training is established for organic coronary artery disease but remained to be examined for VSA.

Purpose

We thus examined whether vasodilator capacity of coronary microvessels is impaired in VSA patients without organic coronary stenosis using an adenosine-stress dynamic computed tomography perfusion (CTP) that can measure absolute value of myocardial blood flow (MBF). We also examined whether exercise training ameliorates not only vasodilator capacity of coronary microvessels but also exercise capacity and frequency of angina attack.

Methods

In the first protocol, we measured MBF using CTP in consecutive 32 VSA patients with acetylcholine-induced diffuse coronary spasm in the left anterior descending coronary arteries (LAD) and 12 non-VSA controls. In the second protocol, we conducted a randomized controlled trial (RCT; Exercise VSA trial, UMIN: ehz745.008423996), where 20 VSA patients were randomly assigned to either exercise group (Ex group: supervised exercise training session for 30-min using bicycle ergometer, once/week at the hospital and more than 3 times/week at home) or non-exercise group (Non-Ex group) (n=10 each) (Figure A). Before and 3 months after exercise training, we measured MBF with adenosine-stress dynamic CTP and peak VO2 by cardiopulmonary exercise tests, and also assessed angina attack with Seattle Angina Questionnaire (SAQ).

Results

In the first protocol, CTP showed that adenosine-stress MBF was significantly decreased in the VSA group compared with the non-VSA group (VSA, 137.2±6.6 vs. Non-VSA, 174.4±10.7 ml/100g/min, P<0.01) (Figure B), although patient characteristics were comparable between the 2 groups. In the second protocol, exercise training was performed safely in all patients, and RCT showed that MBF was significantly increased in the Ex group compared with the non-Ex group (Figures C, D), although patient characteristics were also comparable between the 2 groups. Furthermore, peak VO2 was significantly increased in the Ex group compared with the non-Ex group (Figure E), and frequency of angina was significantly decreased in the Ex group compared with the non-Ex group (Figure F). Finally, there was a significant positive correlation between the extents of the changes in peak VO2 and the SAQ score for angina frequency in the Ex group (P<0.01, R=0.67).

Figures

Conclusions

These results provide the first evidence that vasodilator capacity of coronary microvessels is impaired in VSA patients, which can be ameliorated by exercise training.

P3780Clinical characteristics and outcomes in Japanese atrial fibrillation patients with valvular heart disease: the Fushimi AF registry

Background

Previous studies have suggested that valvular atrial fibrillation (VAF), defined as atrial fibrillation (AF) patients with prosthetic valve or rheumatic mitral stenosis, increased the risks of thromboembolism. However, clinical characteristics and outcomes of VAF and non-valvular AF (NVAF) patients with other valvular heart disease (VHD) has not been fully described.

Method

The Fushimi AF Registry was designed to enroll all of the AF patients. In the entire cohort (4,454 patients), follow-up data including echocardiography data were available for 3,566 patients. We compared clinical characteristics and outcomes between 131 VAF patients (3.7%), 583 NVAF with VHD (NVAF-VHD: 16.3%) and 2,852 without VHD (Non-VHD: 80.0%).

Result

Compared with Non-VHD, patients in VAF and NVAF-VHD were older (VAF vs. NVAF-VHD vs. Non-VHD: 74.3 vs. 76.9 vs. 72.9 years, respectively; p≤0.0001), more often female (56.5% vs. 51.1% vs. 36.9%, p≤0.0001), less in body weight (54.3 vs. 54.7 vs. 60.6 kg, p≤0.0001), more persistent/permanent type (64.1% vs. 65.4% vs. 45.8%, p≤0.0001), more likely to have heart failure (61.8% vs. 53.2% vs. 23.3%, p≤0.0001), had higher CHADS2 score (2.18 vs. 2.49 vs. 1.96, p≤0.0001) and CHA2DS2-VASc score (3.71 vs. 4.02 vs. 3.26, p≤0.0001), and received oral anticoagulant prescription more frequently (78.6% vs. 63.0% vs. 55.6%, p0.0001). NVAF-VHD was more likely to have previous stroke/systemic embolism (SE) than VHD or Non-VHD (14.5% vs. 23.5% vs. 19.6%, p=0.03). VAF or NVAF-VHD had larger left atrium than Non-VHD (50.5 vs. 47.2 vs. 42.4 mm, p<0.0001). Heart rate, diabetes mellitus and previous bleeding were comparable between the groups.

During the median follow-up of 1,471 days, the incidence rate of stroke/SE was not significantly different between three groups, however, NVAF-VHD showed modestly higher rate than Non-VHD (1.67 vs. 1.96 vs. 1.28 per 100 person-years, respectively, log rank p=0.054) (Figure). The incidence rates of all-cause death (4.62 vs. 5.74 vs. 3.21, p≤0.0001), cardiac death (1.07 vs. 1.01 vs. 0.44, p=0.0003), and those of hospitalization for heart failure (3.29 vs. 4.41 vs. 1.80, p≤0.0001) were higher in NVAF-VHD and VAF, than Non-VHD. After adjustment by relevant factors including the components of CHA2DS2-VASc score and oral anticoagulant use, NVAF-VHD, but not VAF, was an independent predictor for hospitalization for heart failure. Neither VAF nor NVAF-VHD was predictors for all-cause death, cardiac death or stroke/SE.

Figure 1. Incidence of stroke/SE

Conclusion

As compared with Non-VHD, the risk of stroke/SE in VAF and NVAF-VHD was not particularly high; although NVAF-VHD had modestly higher rate than Non-VHD. VAF and NVAF-VHD were associated with higher incidence rates of all-cause death, cardiac death and hospitalization for heart failure. NVAF-VHD was an independent predictor for hospitalization for heart failure in multivariate analysis.

Acknowledgement/Funding

Pfizer, Bristol-Myers Squibb, Boehringer Ingelheim, Bayer Healthcare and Daiichi Sankyo

P5663Impact of proteinuria on cardiovascular outcomes in Japanese diabetic patients with atrial fibrillation: the Fushimi AF Registry

Background

Previous studies have suggested that proteinuria is independently associated with clinical outcomes in diabetic patients, irrespective of the presence of renal dysfunction. However, data regarding the impact of proteinuria on clinical outcomes in diabetic patients with atrial fibrillation (AF) are limited.

Methods

The Fushimi AF Registry is a community-based prospective survey of AF patients in our city in Japan. Follow-up data were available in 4,454 patients, and 634 diabetic patients with available data of proteinuria and estimated glomerular filtration rate (eGFR) were examined. We compared the clinical background and outcomes between patients with proteinuria (n=251) and those without (n=383). Then, we divided the patients into 4 subgroups according to the presence of proteinuria and renal dysfunction, and compared the clinical outcomes between groups; group 1 (without proteinuria, eGFR ≥60 ml/min/1.73 m2; n=203), group 2 (with proteinuria, eGFR ≥60; n=96), group 3 (without proteinuria, eGFR <60; n=180), group 4 (with proteinuria, eGFR <60; n=155).

Results

Age was comparable between patients with or without proteinuria. Patients with proteinuria had higher prevalences of previous heart failure (HF), stroke/systemic embolism, hypertension and renal dysfunction. The prevalences of previous myocardial infarction, and major bleeding were similar between two groups. During the median follow-up of 1,505 days, the incidence rates of HF hospitalization (4.1/100 person-years vs. 2.5/100 person-years; p<0.01) and cardiovascular death (1.8/100 person-years vs. 0.4/100 person-years; p<0.01) were higher in patients with proteinuria. When we divided patients into 4 subgroups, the incidences of HF hospitalization (group 1: 1.8/100 person-years vs. group 2: 3.4/100 person-years vs. group 3: 3.8/100 person-years vs. group 4: 4.9/100 person-years; p<0.01) and cardiovascular death (group 1: 0.3/100 person-years vs. group 2: 1.8/100 person-years vs. group 3: 0.5/100 person-years vs. group 4: 2.2/100 person-years; p<0.01) tended to be higher in not only group 3 and group 4 but also group 2 than group 1 (Figure). Multivariate Cox proportional hazards regression analysis including female gender, age (≥75 years), hypertension, pre-existing HF, renal dysfunction (eGFR <60),low left ventricular ejection fraction (<40%) and proteinuria revealed that proteinuria was an independent determinant of both of HF hospitalization (adjusted hazard ratio [HR]: 1.57, 95% confidence interval [CI]: 1.05–2.34) and cardiovascular death (HR: 3.76, 95% CI: 1.59–8.88).

Figure 1

Conclusion

In Japanese diabetic patients with AF, proteinuria was associated with higher incidences of HF hospitalization and cardiovascular death, irrespective of the presence of renal dysfunction.

P2458Restricted left atrial motion as a result of atrial stiffening in patients with cardiac amyloidosis

Background

Left atrial (LA) involvement of abnormal amyloid fibrils could induce LA dysfunction and stiffening in patients with cardiac amyloidosis (CA). Thus, the assessments of LA function and stiffness might be a potential approach to diagnose CA phenotype among patients with hypertrophied hearts.

Purpose

We sought to determine whether LA reservoir strain with speckle tracking echocardiography could be used a marker of LA stiffness in a derivation cohort. Furthermore, we tested to our hypothesis that LA reservoir strain could differentiate CA patients from hypertrophic cardiomyopathy (HCM) in an independent validation cohort.

Methods

In the derivation cohort, echocardiography was performed simultaneously with measurements of pulmonary capillary wedge pressure (PCWP) in 50 patients with suspected or established heart failure and relatively preserved left ventricular (LV) ejection fraction (56±10%). LA maximum and minimum volume index, and reservoir strain were measured from apical four-chamber view. LA stiffness index was computed as a pressure rise from x-trough to v-wave divided by an increase from minimum to maximum indexed LA volume (Figure A). In an independent validation group, we studied a total of 33 biopsy-proved CA patients and 127 HCM patients (LV ejection fraction: 57±11% vs. 66±10%, P<0.01) in sinus rhythm on the date of comprehensive echocardiographic study. Among them, cardiac magnetic resonance imaging (CMR) could be evaluated in 17 CA patients and 98 HCM patients. Furthermore, right heart catheterization was performed with 12 CA patients and 12 HCM patients in the CMR group.

Results

The derivation cohort study found that there was a significant curvilinear correlation of LA reservoir strain to LA stiffness index (Figure B). In the validation cohort, LA reservoir strain was reduced in patients with CA compared with HCM in all participants (11.6±5.6% vs. 18.5±6.9%, P<0.01), although there was no significant difference of LA maximal volume index between 2 groups (37±16 ml/m2 vs. 37±12 ml/m2, p=0.89). In the CMR group, the late gadolinium enhancement was observed in the LA wall in 16 patients with CA (94.1%) as shown in Figure C. In contrast, the LA enhancement revealed only in 1 patient with HCM (1.0%). Among patients with invasive measures, LA stiffness index [median (interquartile range)] was higher in patients with CA than that in patients with HCM [1.1 (0.4–2.8) vs. 0.2 (0.1–0.6), P=0.01].

Conclusions

LA reservoir function was fairly limited in patients with CA compared with HCM. Restricted LA motion might be related to atrial amyloid deposits or fibrosis, which potentially provokes atrial chamber stiffening.

P4156Coexistence and prognostic impacts of epicardial and microvascular coronary dysfunctions in patients with chest pain and unobstructive coronary artery disease - Involvement of Rho-kinase activation

Background

Although the importance of coronary functional abnormalities has been emerging, including epicardial coronary spasm (vasospastic angina, VSA) and coronary microvascular dysfunction (CMD), comprehensive evaluation of the abnormalities in the same population remains to be examined.

Purpose

We examined the significance of coronary functional abnormalities in a comprehensive manner for both epicardial and microvascular coronary arteries in patients with chest pain and unobstructive coronary artery disease (CAD) as well as their prognostic impacts.

Methods and results

We prospectively enrolled 187 consecutive patients with suspected angina and unobstructive coronary arteries (M/F 113/74, 63.2±12.3 [SD] yrs.). We performed acetylcholine (ACh) provocation tests for coronary spasm, followed by functional tests for coronary microvascular function, including coronary flow reserve (CFR) and index of microcirculation resistance (IMR) during hyperemic state induced by intravenous adenosine. Among the 187 patients, ACh test identified 128 patients with VSA (68%). There was no significant difference in age, sex, or prevalence of traditional coronary risk factors between the non-VSA and the VSA groups. The median IMR value was significantly higher in the VSA group than in the non-VSA group [17.5 (12.0, 25.3) vs. 14.7 (10.7, 17.8), P=0.02], whereas CFR values were comparable between the 2 groups [2.51 (1.72, 3.35) vs. 2.66 (1.85, 3.64), P=0.34]. During the median follow-up period of 893 days, major adverse cardiac events (MACE), including cardiac death, non-fatal myocardial infarction, and hospitalization due to unstable angina pectoris, occurred in 10 patients (5.3%). Multivariable analysis revealed that IMR correlated with the incidence of MACE [hazard ratio (HR) (95% confidence interval), 1.05 (1.02–1.09), P=0.002] and receiver-operating characteristics curve analysis identified IMR of 18.0 as the optimal cut-off value for the incidence of cardiac events. When we divided the patients into the following 4 groups according to the cut-off value of IMR (>18) and the presence or absence of VSA; G1, IMR <18 without VSA (n=45); G2, IMR ≥18 without VSA (n=14); G3, IMR <18 with VSA (n=67); and G4, IMR ≥18 with VSA (n=61), the Kaplan-Meier survival analysis showed a significantly worse prognosis in G4 compared with other 3 groups (HR [95% CI] 6.23 [1.21–118.46], P=0.002) (Figure 1). Importantly, intracoronary administration of fasudil, a Rho-kinase inhibitor, significantly ameliorated IMR in G4 (P<0.0001) (Figure 2A), and %changes in IMR in response to intracoronary fasudil were more evident in G4 compared with other 3 groups (P<0.0001) (Figure 2B).

Conclusions

These results provide the first evidence that in patients with chest pain and unobstructive CAD, epicardial coronary spasm and increased microvascular resistance are frequently coexisted with worse long-term prognosis, for which Rho-kinase activationmay be involved.

P3758Clinical characteristics and outcomes of atrial fibrillation patients with thrombocytopenia: the Fushimi AF Registry

Background

Thrombocytopenia is sometimes found in routine blood tests and is reported as a risk factor of major bleeding events and incidence of all-cause death after percutaneous coronary intervention. However, the influence of thrombocytopenia on clinical outcomes in patients with atrial fibrillation (AF) remains unknown.

Purpose

We aimed to investigate relationship between baseline platelet count and clinical outcomes such as all-cause death, hospitalization for heart failure, and the major bleeding event in AF patients.

Methods

The Fushimi AF Registry was designed to enroll all of the AF patients in Fushimi-ku, Kyoto. Fushimi-ku is densely populated with a total population of 283,000 and is assumed to represent a typical urban community in Japan. Follow-up data with baseline platelet counts were available in 4,179 patients from March 2011 to November 2018. We divided the entire cohort into 3 groups according to baseline platelet level: No thrombocytopenia (≥150,000/μL, n=3,323), Mild thrombocytopenia (100,000–149,999/μL, n=707), and Moderate/severe thrombocytopenia (≤99,999/μL, n=149).

Results

In the entire cohort, the mean age was 73 years, 40% were women, and the mean body weight and body mass index was 59 kg and 23.1 kg/m2, and the median platelet count were 192,000/μL (interquartile range 156,000 to 232,000/μL), respectively.

Compared to No thrombocytopenia, patients with thrombocytopenia were older (No vs. Mild vs. Moderate/severe; 73.3 years vs. 76.5 years vs. 75.8 years, p<0.0001), more likely to have heart failure (27.0% vs. 32.8% vs. 41.6%, p<0.0001), more likely to have chronic renal disease (35.7% vs. 42.6% vs. 57.7%, p<0.0001), and had higher CHADS2 score (2.05 vs. 2.17 vs. 2.34, p=0.0039) and CHA2DS2-VASc score (3.40 vs. 3.52 vs. 3.71, p=0.0416). Patients with thrombocytopenia had lower hemoglobin (13.0 vs. 12.8 vs. 11.6, p<0.0001) than No thrombocytopenia. However, prevalence of previous major bleeding events was comparable between three groups (4.66% vs. 4.67% vs. 5.37%, p=0.92)

On Kaplan-Meier analysis, the incidence of all-cause death was higher in Mild group (hazard ratio [HR] 1.51; 95% confidence interval [CI] 1.28–1.77) and Moderate/severe group (HR 2.97; 95% CI 2.28–3.80) than No group (Figure 1). The incidence of hospitalization for heart failure was higher in Mild group (HR 1.62; 95% CI 1.31–1.99) and Moderate/severe group (HR 2.64; 95% CI 1.76–3.81) than No group (Figure 2). The incidence of major bleeding event was higher in Mild group (HR 1.46; 95% CI 1.11–1.91) and Moderate/severe group (HR 2.45; 95% CI 1.41–3.91) than No group (Figure 3).

Conclusion

Thrombocytopenia in AF patients was associated with higher incidence of all-cause death, hospitalization for heart failure, and major bleeding event in the Fushimi AF Registry.

Acknowledgement/Funding

Pfizer, Bristol-Myers Squibb, Boehringer Ingelheim, Bayer Healthcare,and Daiichi-Sankyo

Purification, Rheological Characterization, and Visualization of Viscous, Neutral, Hetero-exopolysaccharide Produced by Lactic Acid Bacteria

Viscous exopolysaccharide (EPS)-producing lactic acid bacteria (LAB) have received increasing interest in the dairy industry because of their capability to improve the texture and mouthfeel of fermented dairy products. To date, enormous efforts have been made to reveal the relationship between texture and EPS production in fermented milk products such as yogurt. However, the structure-rheology relationship of EPSs themselves is not yet well understood due to their low yields in general and their wide variety of chemical structures. In this chapter, we describe common techniques for the purification, visualization, and rheological analysis of viscous EPSs produced by LAB.

X-Ray Spectrometer for EXAFS Using a Position Sensitive Detector

An active recording x-ray crystal spectrometer for extended x-ray absorption fine structure (EXAFS) has been built using a position sensitive detector of the self scanning photodiode array (SSPA) type. The SSPA detector has energy and position sensitivity for x-rays. The spectrometer was applied to the measurement for EXAFS of the several compounds in foil, powder and liquid states. The spectra can be obtained rapidly, and compare very well with other methods. We found that the SSPA detector is very useful for the measurement of EXAFS.