Effects of smoking cessation on endothelial function assessed by flow-mediated dilation and reactive hyperemia peripheral artery tonometry

Background

Smoking predisposes individuals to endothelial dysfunction. Both flow-mediated dilation (FMD) and reactive hyperemia peripheral artery tonometry (RH-PAT) are used to assess endothelial function. However, there are differences in the physiology of vascular beds being tested and in the response of conduit and resistive vessels to RH. Therefore, whether smoking cessation demonstrates comparable effects on endothelial function evaluated by FMD and by RH-PAT remains unclear.

Purpose

We aimed to evaluate the effects of smoking cessation on endothelial function evaluated simultaneously by FMD and RH-PAT.

Methods

Thirty-eight consecutive current smokers (mean±standard deviation; age, 65±10 years) who visited our smoking cessation outpatient department and succeeded in smoking cessation with varenicline were enrolled. Clinical variables, FMD, and natural logarithmic transformation of the reactive hyperemia index (Ln-RHI) were examined before and 20 weeks after treatment initiation. Fifteen current smokers who failed in smoking cessation were enrolled as age- and sex-matched controls. The Spearman's rank correlation coefficient and intraclass correlation coefficient (ICC) for a two-way mixed effects model were performed to assess the agreement of changes in FMD and Ln-RHI. Multivariate logistic regression analysis was performed to examine the associations between the presence of increase in FMD or Ln-RHI and clinical variables.

Results

FMD significantly improved after smoking cessation (3.42%±1.96% to 4.45%±2.28%; p=0.019), whereas Ln-RHI did not (0.53±0.25 to 0.59±0.21; p=0.223). The Spearman's rank correlation coefficient between changes in FMD and Ln-RHI was −0.013, and the ICC was −0.002 (p=0.506). In the multivariate logistic regression analysis, an increase in FMD or Ln-RHI was predicted based on the baseline FMD (odds ratio = 0.54, p=0.013) or Ln-RHI (odds ratio = 0.36, p=0.012), respectively, after adjusting for age and sex.

Conclusions

There was significant improvement in the endothelial function assessed by FMD, but not by Ln-RHI, after smoking cessation. In addition, there was disagreement between changes in FMD and those in Ln-RHI. Smoking cessation may have varying effects on the endothelial function of the conduit and digital vessels.

Funding Acknowledgement

Type of funding source: Public grant(s) – National budget only. Main funding source(s): Grant-in-aid for scientific research from the ministry of education, science and culture of Japan

Clinical significance of controlling nutritional status score for predicting short-term clinical events in takotsubo syndrome: a multicenter study

Background

The Controlling Nutritional Status (CONUT) score is well known as a marker of nutritional status. Previous studies have reported that CONUT score could predict a prognosis of acute or chronic heart failure, and infective endocarditis. Takotsubo syndrome (TTS) is said to have a relatively good prognosis, but some patients have a bad turning point in hospital stay. Lower systolic blood pressure on admission, history of diabetes mellitus, and β-blocker use before admission have been reported as predictors of in-hospital cardiac complications. However, the prognostic utility of CONUT score in TTS is unclear. The aim of study was to evaluate duration of hospital stay and short-term clinical events with CONUT score in TTS.

Methods

Seventy-nine TTS patients who were admitted to 3 medical centers in Japan between January 2011 and October 2019 were enrolled. The average age was 71.8±11.5 years old, and the prevalence of female sex was 81%. The CONUT score was calculated based on the serum albumin, total lymphocyte and total cholesterol on admission. We retrospectively investigated the association between the short-term clinical events and CONUT score. The duration of hospital stay was defined as the primely outcome, and all cause death and congestive heart failure in hospital stay as the secondary outcome.

Results

The average CONUT score was 3.7±3.0. A positive correlation was found between the CONUT score and the duration of hospital stay (r=0.56, p<0.01). Twenty (25.3%) patients suffered from clinical events (all cause death and congestive heart failure in hospital). Those patients with clinical events had significantly higher the CONUT score than those without (all cause death, 7.2±2.6 vs. 3.5±2.9, p<0.01, congestive heart failure, 5.3±3.4 vs. 3.3±2.8, p=0.02, composite clinical events, 5.8±3.2 vs. 3.0±2.6, p<0.01). ROC curve analysis revealed that the optimal cut-off value of the CONUT score for the prediction of composite clinical events was 4.0 (AUC: 0.75, sensitivity: 80%, Specificity: 64%). The patients with CONUT score of 4 or more (high COUNT score) were more prevalent in patients who experienced composite clinical events than in those who didn't (80% vs. 35.6%, p<0.01). The patients with a high CONUT score had a longer hospital stay and higher occurrence of composite clinical events than those with CONUT score less than 4 (respectively, 27.2±19.1 days vs. 13.8±8.3 days, p<0.01, 25.3% vs. 9.5%, p<0.01).

Conclusions

The CONUT score in TTS patients was strongly associated with the duration of hospital stay and clinical events in hospital. The CONUT score is a simple indicator that can be calculated with only three factors. Therefore, the CONUT score on admission may be useful for a predictor of short-term clinical events in TTS patients.

Funding Acknowledgement

Type of funding source: None

Treatment of complex coronary artery disease in patients with diabetes mellitus and chronic kidney disease: 10-year results comparing outcomes of CABG and PCI in the SYNTAXES trial

Background

The SYNTAX Extended Survival (SYNTAXES) study is an investigator-driven extension of follow-up of the SYNTAX trial, which was a non-inferiority trial that compared percutaneous coronary intervention (PCI) using first-generation paclitaxel-eluting stents with coronary artery bypass grafting (CABG) in patients with de-novo three-vessel and left main coronary artery disease. The SYNTAXES study is the first randomized trial that reported the complete 10-year data on all-cause death in patients with complex coronary artery disease.

Purpose

Patients with coronary artery disease (CAD) and concomitant diabetes mellitus (DM) or chronic kidney disease (CKD) are more susceptible to major adverse cardiovascular and cerebrovascular events. However, to date, the long-term prognosis and which revascularization strategy was associated with better clinical outcomes for patients with complex coronary artery disease and concomitant with DM and CKD have not been documented.

Methods

In this sub-analysis of the SYNTAXES trial, a total of 1,638 patients were classified into four subgroups according to the DM and CKD status: DM−/CKD− (n=999, 60.1%), DM+/CKD− (n=323, 19.7%), DM−/CKD+ (n=231, 14.1%), and DM+/CKD+ (n=85, 5.2%). The treatment effects of PCI and CABG were analyzed in each subgroup. The primary endpoint was all-cause death at 10 years.

Results

Compared with the DM−/CKD− patients, patients with DM+/CKD+ were older, more often had a history of stroke, hypertension, heart failure, and were more frequently presented with total occlusion, bifurcation lesion and three-vessel disease. At 10 years, patients with DM+/CKD+ had a 3.94-fold higher incidence of all-cause mortality compared with DM−/CKD− individuals (54.1% versus 18.9%, 95% CI [2.85–5.44]). Patients with DM−/CKD+ (38.1%, HR 2.36; 95% CI [1.83–5.44]) or DM+/CKD− (28.2%, HR 1.61; 95% CI [1.26–2.07]) had intermediate risk profile. For DM+/CKD+ patients, compared with PCI, those who underwent CABG were associated with lower incidence of all-cause mortality (64.3% versus 44.2%, adjusted HR 0.52; 95% CI [0.27–0.99], p=0.047, pinteraction=0.443). The number of needed-to-treat to reduce mortality for CABG was 12.

Conclusion

In the SYNTAX population, patients with DM and CKD are at markedly increased risk of long-term mortality rate compared with patients one or neither of these risk factors. For patients with both comorbidities, CABG was associated with better clinical outcome compared with PCI. These findings should be interpreted as hypothesis-generating.

Figure 1. Kaplan-Meier curves showing the clinical events according to treatment and DM/CKD status.

Funding Acknowledgement

Type of funding source: Private company. Main funding source(s): Boston Scientific Corporation

Impact of periprocedural myocardial infarction on 10-year mortality after percutaneous coronary intervention or coronary artery bypass grafting for multivessel or left main coronary artery disease

Background

Periprocedural myocardial infarction (PMI) occurs frequently after both percutaneous coronary intervention (PCI) and bypass grafting surgery (CABG) in patients with complex coronary artery disease (CAD), and PMI has been shown to have a detrimental impact on mortality. On the other hand, long-term impact of PMI on mortality has not been fully evaluated.

Purpose

This study aimed to assess the impact of PMI according to SCAI definition on 10-year all-cause death in patients with complex CAD.

Methods

The SYNTAX Extended Survival (SYNTAXES) study evaluated vital status up to 10 years in 1800 patients with de novo three-vessel disease and/or left main coronary artery disease randomized to treatment with CABG or PCI in the SYNTAX trial. Blood was sampled for creatine kinase (CK) pre- and post-revascularisation, and the cardiac specific MB iso-enzyme (CK-MB) was determined only if the CK ratio ≥2 x the upper limit of normal (ULN). If the CK ratio <2 ULN, CK-MB assessment was not mandated. In this analysis, patients with at least one blood sampling within 48 hours of the procedure were included. PMI was defined as follows; peak CK-MB measured within 48 hours of the procedure ≥10 x ULN, or ≥5 x ULN with new Q-waves in 2 contiguous leads or new persistent left bundle branch block.

Results

Of 1800 patients, 1679 (93.2%) patients were included. Of 877 patients treated with PCI, PMI occurred in 26 patients (3.0%), whereas 14 (1.7%) PMIs were observed in 802 patients treated with CABG. Compared with patients without PMI, patients with PMI presented with unstable angina more frequently (45.0% vs. 28.7, p=0.033), and had a higher rate of bifurcation lesion (87.5% vs. 72.5, p=0.046). PMI was associated with a higher all-cause mortality at 10 years compared with no PMI (55.3% vs. 25.4%; Log-rank p<0.001, Figure), which was mainly driven by a high mortality rate within 1 year. In patients undergoing PCI, the mortality rates were significantly higher in patients with PMI not only within 1 year (Log-rank p<0.001) but also beyond one year (Log-rank p=0.016), compare to patients without PMI (Figure). On the other hand, in patients undergoing CABG, a higher mortality rate in patients with PMI was observed until 1 year (Log-rank p<0.001), but the impact of PMI on mortality beyond one year after CABG subsided (Log-rank p=0.308) (Figure 1).

Conclusion

PMI was associated with a poor prognosis at 10 years. The impact of PMI on mortality was strong within one year. Of note, the impact of PMI on mortality persisted beyond 1 year only in patients undergoing PCI. Patients who were treated with PCI and suffered PMI need careful follow-up beyond one year after revascularization.

Figure 1

Funding Acknowledgement

Type of funding source: None

Ten-year all-cause death in elderly patients undergoing percutaneous coronary intervention or coronary artery bypass grafting: a prespecified subgroup analysis of the SYNTAX Extended Survival study

Background

Coronary artery disease is the leading cause of death among elderly men and women worldwide. The aging society worldwide will lead to increasing numbers of elderly patients with multivessel coronary artery disease. Although age is recognized as one of the most important factors in a decision-making for revascularization of multivessel coronary artery disease, the very long-term outcomes in patients undergoing revascularization by percutaneous coronary intervention (PCI) or coronary artery bypass grafting (CABG) is still unclear.

Objectives

The aim of the present study was to investigate the association between revascularization strategies and 10-year outcomes in elderly patients.

Methods

The SYNTAX Extended Survival (SYNTAXES) study (NCT 03417050) is an investigator-driven extension of follow-up of a multicentre, randomised controlled trial done in 85 hospitals across 18 North American and European countries, enrolling 1,800 patients with de novo three-vessel disease (3VD) and/or left main coronary artery disease (LMCAD) randomized to revascularization strategy with CABG versus PCI in the SYNTAX trial. Patients were divided into two groups according to the prespecified threshold of 70 years old; elderly patients (>70 years) and non-elderly patients (≤70 years). The primary endpoint of this study was all-cause death at 10 years.

Results

Out of 1,800 patients, 575 patients (31.9%) were classified as elderly (>70 years). The mean age ± standard deviation (SD) of the elderly patients and the non-elderly patients was 75.8±3.6 years and 60.1±7.4 years, respectively. Of note, elderly patients were more frequently female than non-elderly patients (33.6% vs. 17.1%, p<0.001). As expected, the elderly patients had higher prevalence of chronic kidney disease (43.4% vs. 7.9%, p<0.001), had higher anatomical SYNTAX score (30.2±11.8 vs 28.0±11.2 p<0.001) when compared to those of the non-elderly patients.

Up to 10 years, all-cause death occurred in 42.7% and 18.9% in the elderly and non-elderly patients, respectively (Log-rank p<0.001). The cubic spline curve showed an exponentially increase in all-cause death at 10 years according to the increase of age both in the PCI arm and the CABG arm. At 10 years, there was no significant difference in the risk of all-cause death between CABG vs. PCI either in elderly patients (41.5% vs. 44.0%; Log-rank p=0.53) or non-elderly patients (16.6% vs. 21.1%; Log-rank p=0.051).

Conclusion

CABG and PCI were equipoise in terms of risk of all-cause death at 10 years in patients with de novo 3VD and/or LMCAD irrespective of their age when stratified according to the prespecified threshold of 70 years old.

Kaplan-Meier curves

Funding Acknowledgement

Type of funding source: Foundation. Main funding source(s): German Foundation of Heart Research

Stretch-Shortening Cycle Function of Lower Limbs After Cycling in Triathletes

Takahashi, K, Shirai, Y, and Nabekura, Y. Stretch-shortening cycle function of lower limbs after cycling in triathletes. J Strength Cond Res XX(X): 000-000, 2020-Impaired cardiorespiratory response and changes in biomechanical variables occur when running after cycling relative to isolated running. Nevertheless, little is known about the causes of these changes or the training to prevent them. This study aimed (a) to determine whether stretch-shortening cycle (SSC) function decreases after cycling exercise and (b) to determine whether the decreases in SSC function are related to brick training. Eleven male university triathletes performed hopping tests to measure SSC function before and after cycling (30 minutes of cycling at 110% ventilatory threshold). Stretch-shortening cycle function was calculated as the ratio of the jump height to the time spent in contact with the ground (reactive strength index [RSI]). Brick training was evaluated by the total experience of brick training. The RSI significantly decreased after the cycling exercise (-10.7%; p < 0.01), but changes in RSI after cycling did not significantly correlate with the total experience of brick training, despite a large effect size (p < 0.10; r = 0.62). These results suggest that SSC function decreases after cycling and that brick training is potentially useful for inhibiting decreases in SSC function after cycling.

Frailty Checkup Supporters' Intentions to Participate in Human-Resource Development and Training Activities

BACKGROUND

Frailty prevention is one of social prescriptions for an aging society. That requires community level intervention.

OBJECTIVES

This study examined frailty checkup supporters' (FCSs') intentions to engage in human-resource development and training activities (i.e., leadership activities) and related factors.

DESIGN

Cross-sectional study.

SETTING

Three municipalities in suburban area, Eastern Japan.

PARTICIPANTS

Forty-five of 59 FCSs completed anonymous self-administered questionnaires.

MEASUREMENTS

Questionnaire sought information regarding their sociodemographic data, their perceptions and experiences of FCS activities, and their intentions to participate in human-resource development and training activities. Participants were divided into a high intention (HI) and low intention group (LI). The two groups were compared using quantitative and qualitative data.

RESULTS

Eleven FCSs reported intending to engage in leader-related activities. Factors associated with FCSs' intentions were finding FCS activities rewarding and the willingness to continue performing FCS activities. The participants who changed their daily activities (p = .041) and perceptions regarding contributing to the community (p = .018) showed significantly higher intention than LI participants. Free description about the changes in perceptions and lifestyles as a consequence of participating in FCS activities were analyzed qualitatively. FCSs who changed their daily activities and perspectives about contributing to the community described positive changes in both the groups. Meanwhile, FCSs who did not change their daily activities and perspectives about contributing to the community described their reason only in the LI group.

CONCLUSIONS

The results might encourage FCSs to participate in training and guidance activities, as they have positive experiences and receive recognition obtained through participation in such activities.

Reduction of extracellular sodium evokes nociceptive behaviors in the chicken via activation of TRPV1

Transient receptor potential vanilloid 1 (TRPV1), a non-selective cation channel, is mainly expressed in nociceptive primary sensory neurons. Sensitivity of TRPV1 to several stimuli is known to vary among species, specifically, the avian orthologue is nearly insensitive to capsaicin. Extracellular sodium ions ([Na⁺]_o) regulate TRPV1 activity in mammals, but their regulatory role on chicken TRPV1 (cTRPV1) is unknown. Here, we focused on the actions of capsaicin and low [Na⁺]_o on cTRPV1 activity. In chicken dorsal root ganglion (cDRG) neurons, capsaicin elicited [Ca²⁺]_i increases, but its effective concentration was much higher than those in mammals. Low [Na⁺]_o evoked [Ca²⁺]_i increases in cDRG neurons in a decreasing [Na⁺]_o-dependent manner and the complete removal of [Na⁺]_o (0Na) produced maximal effects. The population of 0Na-sensitive neurons was mostly overlapped with those of proton- and capsaicin-sensitive ones. Low [Na⁺]_o synergistically potentiated the capsaicin- and proton-induced TRPV1 activation in cDRG neurons. In HEK293 cells expressing cTRPV1 (cTRPV1-HEK), capsaicin elicited [Ca²⁺]_i increases with an EC₅₀ of 11.8 µM, and low [Na⁺]_o also did. Well-defined mammalian TRPV1 antagonists hardly suppressed cTRPV1 activation by low [Na⁺]_o. 0Na evoked outwardly rectified currents in cTRPV1-HEK. Mutagenesis analyses revealed a possible interaction of [Na⁺]_o with the proton-binding sites of cTRPV1. The administration of capsaicin and 0Na to chick eyes elicited pain-related behaviors. These results suggest that low [Na⁺]_o is capable of activating cTRPV1 in vitro, resulting in pain in vivo. Our data demonstrate that characterization of the cTRPV1 function is important to understand activation mechanisms of TRPV1.

Effect of lactate administration on exercise-induced PGC-1α mRNA expression in Thoroughbreds

The aim of this study was to examine the effects of lactate administration on the mRNA response of peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PGC-1α) to acute exercise in Thoroughbred skeletal muscle. Five Thoroughbred horses performed treadmill running at 90% of maximal oxygen consumption for 2 min on two separate occasions, either after the administration of two litres of a sodium lactate solution (LAC; 500 mmol/l sodium lactate in 0.9% NaCl) or a saline solution as a control (CON; 0.9% NaCl). Lactate administration significantly elevated the peak plasma lactate concentration during exercise (16.0±2.8 mmol/l in LAC vs 10.8±2.2 mmol/l in CON). The increase in PGC-1α mRNA expression after 4 h of recovery from exercise was similar between treatments. However, there was positive correlation between exercise-induced PGC-1α mRNA response at 4 h after exercise and peak plasma lactate concentration during exercise. These results suggest that the exercise intensity-dependent adaptation of PGC-1α may be attributed, at least in part, to an increased lactate concentration.

Detection of information flow between cortical laminae activities and auditory evoked potentials in rats by means of Granger causality

We seek to understand the relation between invasive high-resolution data and non-invasive measurement in an animal model in an auditory sensory adaptation experimental setting. In a previous study, we estimated the mutual information between the phase of auditory evoked responses (AER) with the phase of local field potentials (LFP) of auditory cortices at different frequency ranges. The results showed a consistently high level of information sharing between the AER activities as well as the responses from the granular layer, which was known as the main thalamo-recipient layer. However, mutual information was fundamentally an undirected measure of information flow. In this study we investigated how well we could characterize direction of information flow, by using Granger causality (GC), between different cortical laminae and functional projections on to the AER activities. We obtained that based on the GC coefficients, we are able to extract the connectivity between different cortical laminae to some extend and also a strong connection between the AER and granular layer. In our future study, we would like to construct a reliable picture of network connectivity, both functionally and anatomically, between different layers at more specified frequencies and much finer temporal resolutions.

Halo Structure of the Neutron-Dripline Nucleus ^{19}B

The heaviest bound isotope of boron ^{19}B has been investigated using exclusive measurements of its Coulomb dissociation, into ^{17}B and two neutrons, in collisions with Pb at 220  MeV/nucleon. Enhanced electric dipole (E1) strength is observed just above the two-neutron decay threshold with an integrated E1 strength of B(E1)=1.64±0.06(stat)±0.12(sys)  e^{2} fm^{2} for relative energies below 6 MeV. This feature, known as a soft E1 excitation, provides the first firm evidence that ^{19}B has a prominent two-neutron halo. Three-body calculations that reproduce the energy spectrum indicate that the valence neutrons have a significant s-wave configuration and exhibit a dineutronlike correlation.

Characteristics of plasma window with various channel diameters for accelerator applications

Plasma window is a feasible device as an atmosphere-vacuum interface, which can withstand energetic particle beams. It is, however, essential to enlarge the diameter to several tens of millimeters for actual beam passing in the accelerator applications. The pressure separation performance and discharge voltage V current I characteristics should be investigated in detail to design the plasma window for each purpose. Therefore, a cascade arc discharge device with a diameter of up to 20 mm was developed, and its characteristics as a function of diameter were examined. As a result, with an increase in the channel diameter, the discharge pressure that was achieved decreased, whose values were smaller compared with the values by the prediction formula, assuming the viscous gas flow with a constant plasma temperature. It showed that the bulk plasma temperature for the larger discharge channel was low because of the low-current density over the channel. Furthermore, the transition of the V-I slope was observed with an increase in the diameter.

Effect of a single bout of exercise on clock gene expression in human leukocyte

Mammals have circadian clocks, which consist of the central clock in the suprachiasmatic nucleus and the peripheral clocks in the peripheral tissues. The effect of exercise on phase of peripheral clocks have been reported in rodents but not in humans. Continuous sampling is necessary to assess the phase of the circadian rhythm of peripheral clock gene expressions. It has been assumed that the expression of the genes in leukocyte may be "an accessible window to the multiorgan transcriptome." The present study aimed to examine whether exercise affects the level and phase of clock gene expression in human leukocytes. Eleven young men participated in three trials, in which they performed a single bout of exercise at 60% V̇o_2max for 1 h beginning either at 0700 (morning exercise) or 1600 (afternoon exercise) or no exercise (control). Blood samples were collected at 0600, 0900, 1200, 1500, 1800, 2100, and 2300 and at 0600 the next morning, to assess diurnal changes of clock gene expression in leukocytes. Brain and muscle ARNT-like protein 1 (Bmal1) expression level increased after morning and afternoon exercise, and Cryptochrome 1 (Cry1) expression level increased after morning exercise. Compared with control trial, acrophase of Bmal1 expression tended to be earlier in morning exercise trial and later in afternoon exercise trial. Acrophase of Cry1 expression was earlier in morning exercise trial but not affected by afternoon exercise. Circadian locomotor output cycles kaput (Clock), Period 1-3 (Per1-3), and Cry2 expression levels and those acrophases were not affected by exercise. The present results suggest a potential role of a single bout of exercise to modify peripheral clocks in humans.NEW & NOTEWORTHY The present study showed that a single bout of exercise affected peripheral clock gene expression in human leukocytes and the effect of exercise depended on when it was performed. Brain and muscle ARNT-like protein 1 (Bmal1) expression was increased after exercises performed in the morning and afternoon. Cryptochrome 1 (Cry1) expression was also increased after the morning exercise. The effect of exercise on acrophase of Bmal1 depended on the time of the exercise: advanced after morning exercise and delayed after afternoon exercise.

Optimization of laser-target parameters for the production of stable lithium beam

A laser ion source coupled with a radio frequency quadrupole linac accelerator is being proposed as a suitable system for the production of a low energy, high-current stable lithium beam. In order to maximize the lithium yield, plasmas generated by laser ablation of different materials based on lithium (Li, LiOH, and LiNbO₃) have been characterized by using a Faraday cup and an electrostatic ion analyzer in the time of flight configuration. A wide range of laser power density has been investigated (10⁹-10¹² W/cm²) using two Nd:YAG lasers operating at different wavelengths (1064 nm and 532 nm), pulse durations (6 ns and 17 ns), and maximum energies (1400 mJ and 210 mJ). This paper outlines the pros and cons of the investigated materials by studying how the ion energy, yields, and charge state distributions are modified when the laser power density is changed. Considerable attention has been paid to the higher charge states of oxygen, which may occur with the same mass-to-charge ratio of Li³⁺. The analysis has evidenced that LiNbO₃ represents a valid target since it allows minimizing the O⁶⁺/⁷Li³⁺ ratio down to 2.5% by using a laser power density of 1.8 × 10¹⁰ W/cm². For such a condition, a Li³⁺ current of 1.4 mA/cm² has been measured.

P1357 Left atrial function decreases with age in patients with repaired tetralogy of Fallot decrease

BACKGROUND

Left ventricular function has been shown to be an important prognostic indicator in patients with repaired tetralogy of Fallot (rTOF) and tends to decrease with age. In recent years, left atrial (LA) function was reported to be a useful prognostic indicator more than or equal to left ventricular function in acquired heart diseases. However, atrial function in rTOF has not yet been sufficiently examined.

PURPOSE

The aim of this study was to investigate the relationship between LA dysfunction and age in rTOF using strain analysis.

METHODS

In order to assess the relationship between LA function and age, we recruited 59 patients with rTOF ranging in age from 5-40 years. We stratified the patients into 3 groups (T1: 5-10 years, T2: 11-20 years, T3: 21-40 years) and divided 54 controls of similar age into 3 corresponding groups (N1, N2, and N3). Two-dimensional speckle tracking images (2D-STI) obtained from four- and two-chamber views were used to assess LA functions by measuring reservoir, conduit, and pump strain. Additionally, we measured the strain rate (SR) in the systole, early diastole, and late diastole.

RESULTS

LA reservoir strain (37.4 ± 2.2% vs. 47.9 ± 1.7%, P= 0.004), LA pump strain (8.3 ± 1.4% vs. 14.1 ± 2.7%, p &lt;.001), atrial systolic LA-SR (1.5 ± 0.4% vs. 2.4 ± 0.6%, p &lt;.001), and systolic LA-SR (1.5 ± 0.3% vs. 2.1 ± 0.4%, p = 0.003) were significantly decreased in T3 compared with N3. Although only LA conduit strain decreased with aging (r = -0.3204, p = 0011) in controls, all of the LA reservoir (r = -0.325, p = 0.020), conduit (r = -0.314, p = 0.025), and pump strain (r = -0.481, p &lt; 0.001) in rTOF decreased with aging.

Early diastole SR was significantly decreased in the T1 and T3 groups compared with the N1 and N3 groups (T1 vs N1, 3.00 ± 0.63% vs. 4.03 ± 0.0.80%, p &lt;.0.001, T3 vs N3, 2.31 ± 0.57% vs.3.31 ± 0.47%, p &lt; 0.001). Both systolic SR and late diastole SR decreased in T3 group compared with the N3 (1.54 ± 0.32% vs. 2.08 ± 0.42%, p = 0.003, 1.42 ± 0.32% vs.2.42 ± 0.61%, p &lt; 0.001), respectively. Although only early diastole SR decreased with aging (r = -0.415, p &lt; 0.001) in controls, all of the systole (r = -0.287, p = 0.041), early diastole (r = -0.337, p = 0.019), and late diastole SR (r = -0.407, p = 0.003) in rTOF decreased with aging.

CONCLUSIONS

In rTOF, most of the LA functions assessed by strain analysis decreased compared to normal controls in over 20 years old age. Furthermore, all measured functions decreased with age in rTOF while only two parameters decreased with age in normal controls. These results suggest that LA function may be an important indicator in long-term rTOF follow-up. These are new insights into LA function in patients with rTOF.

21 The contrasting role of histone methyltransferases during nuclear reprogramming: SUV39H knockdown improves bovine somatic cell nuclear transfer, while the absence of EHMT2 hampers it

The persistence of somatic epigenetic memory is indicated as the main barrier for efficient nuclear reprogramming. The augmented levels of histone methylation on somatic nuclei have been shown as the major regulator of this aberrant remodelling. Although they occupy the same site, H3K9me2 and H3K9me3 are catalysed by different histone methyltransferases (HMTs), EHMT2 and SUV39H, respectively. However, the influence of these HMTs during nuclear reprogramming is unclear. Hence, the main goal of this project was to investigate the role of HMTs responsible for H3K9 methylation during nuclear reprogramming and its consequences on embryo development. For this, we employed a small interfering RNA (siRNA)-mediated knockdown approach targeting EHMT2, SUV39H1, and SUV39H2 in bovine fetal fibroblasts. The RT-qPCR analyses showed ~80% reduction in total RNA after siRNA treatments for the target genes when compared with the control vector. We then quantified the H3K9me2 and H3K9me3 levels by immunostaining. The analysis displayed that H3K9me2 levels were diminished ~50% compared with control, whereas the reduction of H3K9me3 levels was only ~25%. Cells transfected with siRNA targeting EHMT2, SUV39H1, and SUV39H2 (All-siRNA) or control vector (control) were used as a nuclear donor on somatic cell nuclear transfer (SCNT) in five biological replicates. The IVF embryos were used as a biological control for immunostaining analysis. Embryos at both 8- to 16-cell and blastocysts stage (n=10 from 5 replicates) were collected to evaluate the effect of HMT knockdown on H3K9me2 and H3K9me3 levels by immunostaining. We found a reduction of blastocyst rates in the treatment 28±6.3 (mean±s.e.m.) when compared with control 60±4.8 (P=0.004). The immunostaining analysis showed that the levels of H3K9me2 and H3K9me3 were higher in cloned (control) than IVF embryos (P&lt;0.05). Moreover, the All-siRNA group displayed a reduction in H3K9me2 levels compared with the control group and IVF through developmental stages analysed (P&lt;0.05). Differently, H3K9me3 levels were higher in the All-siRNA group at the 8- to 16-cell stage, but no difference was found between treated and control groups at the blastocyst stage. We, therefore, decided to test whether individual knockdown would display a different result. We then used cells transfected with siRNA targeting only EHMT2 (EHMT2-siRNA), targeting SUV39H1 + SUV39H2 (SUV-siRNA), or control vector (control) as a nuclear donor on SCNT in five biological replicates. Surprisingly, the SUV-siRNA group increased blastocyst production 38±4.4 when compared with the control group 29±4.4 (P=0.01), whereas the EHMT2-siRNA showed a reduction in blastocyst rates: 21±5.6 (P=0.04). Our results indicate that EHMT2 has a key role during SCNT, possibly by its crosstalk with other modifications. Even though the SUV39H knockdown induced a small reduction in H3K9me3 levels in the nuclear donor, it was enough to increase the blastocyst rates by 10%. These results will allow us to better understand the complex mechanisms involved in the persistent epigenetic memory during nuclear reprogramming.

P1358 New insights into cardiac dysfunction assessed by left atrial function in patients with type 1 diabetes mellitus

BACKGROUND

There have been many reports of heart failure due to diabetic cardiomyopathy and decreased left ventricular (LV) function with increasing age in patients with type 1 diabetes mellitus (T1DM). Recently, although left atrial (LA) function has been occasionally reported to be a more useful prognostic indicator than LV function in acquired heart diseases, LA function in patients with T1DM has not yet been studied.

PURPOSE

To investigate LA dysfunction in patients with T1DM.

METHODS

Fifty patients with T1DM were recruited (age, 5–41 years). We excluded patients who had a history of heart disease, hypertension, and those taking cardioprotective agents. The patients and 50 age-matched controls were classified into 3 age groups (D1, C1, 5–14 years; D2, C2, 15–29 years; D3, C3, 30–41 years). The LA phasic function serving as the reservoir, conduit, and pump strains; the LA strain rate (SR) in the systole, early diastole, and late diastole; and the LV global longitudinal strain (LV-LS) as determined via 2-dimensional speckle tracking imaging were measured from the apical four- and two-chamber views. We also calculated the LA stiffness index as the ratio of E/e’ to the LA reservoir strain.

RESULTS

There was no significant difference in left ventricular ejection fraction in each age group. The LA reservoir strains in D2 and D3 were significantly lower than those in C2 (40.8 ± 5.7% vs. 47.2 ± 5.5%, p = 0.005) and C3 (39.2 ± 5.5% vs. 47.3 ± 5.7%, p = 0.004), respectively. The LA conduit strain in D2 was significantly lower than that in C2 (28.9 ± 5.8% vs. 35.0 ± 5.0%, p = 0.006). The LA pump strain and the three phases of LA SR were not significantly different among the age groups. The LA stiffness index in D3 increased significantly compared to that in N3 (0.18 ± 0.05 vs. 0.13 ± 0.01, p &lt;0.001). The LV-LS in D2 and D3 was significantly lower than that in C2 (-15.7 ± 1.7% vs. -18.7 ± 2.1%, p &lt;0.001) and C3 (-15.3 ± 1.8% vs. -19.3 ± 2.0%, p &lt;0.001), respectively. The LA reservoir strain significantly correlated with LV-LS (r = -0.468, p &lt; 0.001). Both the LA reservoir strain and LV-LS in patients with T1DM decreased significantly (p = 0.028, p &lt; 0.042, respectively) and correlated with increasing age (r = -0.323, r = 0.286, respectively). The LV stiffness index did not correlate with age or LV-LS.

CONCLUSIONS

The LA reservoir strain might be as useful as LV-LS as an early marker of cardiac dysfunction in patients with T1DM. The correlation coefficient between the LA reservoir strain and LV-LS was not strong. Therefore, although LV-LS might affect the LA reservoir strain, it might represent other aspects of cardiac dysfunction. The increase of LA stiffness might represent the changes in LA wall properties and could be another useful indicator of cardiac dysfunction during long-term follow-ups, which is independent of LV-LS. Overall, these findings provide new insights into cardiac dysfunction in patients with T1DM.

P10 A possible link between sarcopenia and major bleeding risk among patients with atrial fibrillation treated with oral anticoagulation undergoing coronary stenting

Background/Introduction

In patients with atrial fibrillation (AF) undergoing percutaneous coronary intervention (PCI) with stent implantation, oral anticoagulation (OAC) plus dual antiplatelet therapy (DAPT) increases the risk of bleeding. The PRECISE-DAPT (P-DAPT) and DAPT scores were created to predict increased bleeding versus ischemic risk in patients undergoing DAPT. However, not much information is available on predicting bleeding risk associated with OAC concomitant with DAPT in patients with AF treated with coronary stents. Physical frailty or sarcopenia is considered an emerging predictor for bleeding in AF patients.

Purpose

To investigate the relationship between skeletal muscle mass and major bleeding risk in AF patients undergoing PCI and subsequent OAC and DAPT.

Methods

A total of 1,234 consecutive patients after PCI using newer-generation drug eluting stents were evaluated. An anti-thrombotic regimen without OAC was given to 1,077 patients, whereas OAC was required in 157 patients (12.7%) including AF (n = 96). The P-DAPT, DAPT, and HAS-BLED scores were calculated for each of the patients. Any out-of-hospital major bleeding events were identified based on BARC criteria during a median follow-up of 2.9 years. The fat-free mass index (FFMI; kg/m2) was calculated to evaluate skeletal muscle mass as follows: (7.38 + 0.02908 × urinary creatinine (mg/day)) / (height squared (m2)). A Cox proportional hazards model was used to test the significance of the FFMI and these risk scores as predictors of major bleeding, defined as BARC 3 or 5 events in AF patients. The receiver operating characteristic curve (ROC) analyses were used to examine the predictive ability of the FFMI and these scores to identify patients with major bleeding events.

Results

Major bleeding events were observed in 9 (9.3%) patients. Major bleeding was associated with a lower FFMI (hazard ratio [HR] 0.53; 95% confidence interval [CI] 0.36-0.79; p = 0.002), and higher P-DAPT score (HR, 1.07; 95% CI, 1.02-1.11; p = 0.003), but not with the DAPT (HR, 0.71; 95% CI, 0.45-1.12; p = 0.147) and the HAS-BLED score (HR, 1.00; 95% CI, 0.48-2.09; p = 0.990). In the non-OAC cohort, major bleeding was related to a higher P-DAPT score (HR, 1.05; 95% CI, 1.02-1.07; p &lt; 0.0001), but the FFMI (HR, 0.89; 95% CI, 0.73-1.09; p = 0.265) and the DAPT score were not correlated. C-statistics for major bleeding events were 0.82 (95% CI, 0.71-0.93, p = 0.001) for the FFMI and 0.79 (95% CI, 0.68-0.90, p = 0.004) for the P-DAPT score.

Conclusions

Assessment of the FFMI for screening sarcopenia is useful to predict major bleedings specifically in patients with AF undergoing coronary stenting. Both the FFMI and P-DAPT could successfully predict major bleedings in AF patients after PCI. Whether novel bleeding risk scores combined with measuring body composition adequately identify high risk patients needs to be validated.