Prognostic value of estimating appendicular muscle mass in heart failure using creatinine/cystatin C

Objectives

As heart failure with concomitant sarcopenia has a poor prognosis, simple methods for evaluating the appendicular skeletal muscle mass index (ASMI) are required. Recently, a model incorporating anthropometric data and the sarcopenia index, that is, the ratio of serum creatinine to cystatin C (Cre/CysC), was developed to estimate the appendicular skeletal muscle mass. We hypothesized that this model would be superior to the previous model, which uses only anthropometric data to predict the prognosis. This study aimed to compare the prognostic value of low ASMI as defined by the biomarker and anthropometric models in patients with heart failure.

Methods

Among 847 patients, we estimated ASMI using an anthropometric model consisting of age, body weight, and height in 791 patients and a biomarker model that incorporates age, body weight, hemoglobin, and Cre/CysC in 562 patients. Patients were divided into low and non-low ASMI groups according to the ASMI estimated by each model, using the cut-off proposed by the Asian Working Group for Sarcopenia. The primary outcome was all-cause mortality.

Results

Overall, 53.4% and 39.1% of patients were diagnosed with low ASMI by anthropometric and biomarker models, respectively. The agreement of the diagnosis of low ASMI between the two models was poor, with a kappa coefficient of 0.56 (95% confidence interval: 0.49–0.63). Kaplan-Meier curves showed that a low ASMI was significantly associated with all-cause death in both models. However, this association was retained after adjustment for other covariates in the biomarker model (hazard ratio: 2.60, p=0.003), but not in the anthropometric model (hazard ratio: 0.70, p=0.257).

Conclusions and implications

Among patients hospitalized with heart failure, a low ASMI estimated using the biomarker model, but not the anthropometric model, was significantly associated with all-cause mortality.

Funding Acknowledgement

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): Japan Agency for Medical Research and Development

Additional clinical impact of plaque analysis for on-site CT-derived FFR in coronary CT angiography on midterm prognosis

Background

We previously reported that per-patient on-site computed tomography-fractional flow reserve (CT-FFR), which can be acquired on-site workstation using fluid structure interaction during the multiple optimal diastolic phases measured 1 to 2 cm distal to a target lesion may be feasible for risk stratification based on future cardiac events for patients who did not undergo planned revascularization. However, per-vessel CT-FFR and the additional impact of plaque analysis on CT-FFR have not been evaluated.

Purpose

The aim of this study is to assess the clinical and additional impact of novel plaque analysis using labeling method for per-vessel CT-FFR on midterm prognosis.

Methods

A total of 254 consecutive patients with 354 vessels showing 50–90% stenosis but not revascularized within 90 days from coronary CT angiography (CCTA) on 320-row CT were retrospectively analyzed and followed during a median follow up 3.6 years. Plaque characteristics by labeling method (necrotic core/total plaque volume (% necrotic core), non-calcified plaque (NCP)/vessel volume (%NCP), and total plaque/vessel volume (%total plaque) for both total vessel volume (mm3) and at minimum lumen area (MLA, mm2)), positive remodeling (PR) and CT-FFR were analyzed on per-target vessels. The endpoint was vessel oriented-composite outcome (VOCO), including cardiac death, non-fatal MI, and unplanned revascularization.

Results

The incidence of VOCO occurred in 6.8% (24/354). In the cox proportional hazard model, a multivariate analysis identified CT-FFR≤0.80 was the most associated factor with VOCO (all values <0.01 for other plaque morphologies), but %necrotic core, %NCP, %total plaque at MLA and PR were significantly independent of CT-FFR≤0.80. (%necrotic core HR; 3.43 (p<0.01 [95% confidence interval (CI) 1.42–8.29]), %NCP HR; 4.05 (p=0.03 [95% CI 1.19–13.71]), %total plaque at MLA HR; 2.82 (p=0.02 [95% CI 1.18–6.76]), and PR HR; 2.90 (p<0.01 [95% CI 1.30–6.51]), respectively.)

Conclusion

From a view point of clinical outcomes for vessels with moderate to severe stenosis but not revascularized at initial CCTA, CT-FFR demonstrated the significant impact on per-vessel analysis. Moreover, %necrotic core, %NCP and %total plaque at MLA analyzed by labeling method provided better prognostic value in addition to CT-FFR.

Funding Acknowledgement

Type of funding sources: None.

Increasing the class of foundational medication for heart failure is associated with improved prognosis in hospitalized patients with heart failure with reduced or mildly reduced ejection fraction

Aim

To clarify the association between changes in the number of foundational medications for heart failure (FMHF) during hospitalization for worsening heart failure and post-discharge prognosis.

Methods and results

We retrospectively analyzed a combined dataset of three large-scale registries of hospitalized patients with heart failure in Japan (NARA-HF, WET-HF, and REALITY-AHF) and included patients already diagnosed with heart failure with reduced or mildly reduced left ventricular ejection fraction (HFr/mrEF) before admission. Patients were stratified by changes in the number of prescribed FMHF classes, namely angiotensin-converting enzyme inhibitors or angiotensin receptor blockers, beta blockers, and mineralocorticoid receptor blockers, from admission to discharge. The primary endpoint was defined as the combined endpoint of heart failure rehospitalization and all-cause death within 1-year of discharge. The cohort consisted of 1,113 patients, and 482 combined endpoints were observed. In total, 413 (37.1%) patients were on increased FMHF (increased group), 607 (54.5%) remained unchanged (unchanged group), and 93 (8.4%) had a decreased number of FMHF (decreased group) at discharge compared to the time of admission. In multivariable analysis, the increased group was associated with a significantly lower incidence of the primary endpoint compared with the unchanged group (hazard ratio 0.56, 95% confidence interval 0.45–0.60; P<0.001) and decreased group (hazard ratio 0.58, 95% confidence interval 0.40–0.84; P=0.004).

Conclusion

Increasing the number of FMHF cases during heart failure hospitalization is associated with a better prognosis in patients with HFr/mrEF.

Funding Acknowledgement

Type of funding sources: Foundation. Main funding source(s): REALITY registry was funded by the Cardiovascular Research Fund of Japan.WET-HF registry was supported by a Grant-in-Aid for Young Scientists (Y.S. JSPS KAKENHI, 18K15860).

Derivation and validation of a machine learning-based risk prediction model for in-hospital mortality in patients with acute heart failure

Background

Although risk stratification is important in patients with acute heart failure (AHF) to predict patient prognosis, pre-existing risk models have not often been used due to its complexity. Recently, machine learning methods have been presented as an alternative approach to analyzing the predictive probability of large clinical datasets.

Purpose

The aim of this study is to develop a user-friendly risk score developed by one of machine learning methods and compare the performance of the new risk score to the existing conventional risk models.

Methods

A machine-learning-based risk model was developed using least absolute shrinkage and selection operator (LASSO) regression by identifying predictors of in-hospital mortality in the derivation cohort (REALITY-AHF) and externally validating and comparing its performance with two pre-existing risk models: the Get With The Guidelines risk score incorporating brain natriuretic peptide and hypochloremia (GWTG-BNP-Cl-RS) and the acute decompensated heart failure national registry (ADHERE) risk model.

Results

In-hospital deaths in the derivation and validation (NARA-HF) cohorts were 76 (5.1%) and 61 (4.9%), respectively. The risk score comprised four variables (systolic blood pressure, blood urea nitrogen, serum chloride, and C-reactive protein) and was developed according to the results of the LASSO regression weighting the coefficient for selected variables using a logistic regression model (4V-RS). Even though 4V-RS comprised fewer variables, In the validation cohort, it showed a higher area under the receiver operating characteristic curve (AUC) than the ADHERE risk model (AUC, 0.783 vs. 0.740; P=0.059) and a significant improvement in net reclassification (0.359; 95% CI, 0.10–0.67; p=0.006). 4V-RS performed similarly to GWTG-BNP-Cl-RS in terms of discrimination (AUC, 0.783 vs. 0.759; p=0.426) and net reclassification (0.176; 95% CI, −0.08–0.43; p=0.178).

Conclusions

The 4V-RS model comprising only four readily available data points at the time of admission performed similarly to the more complex pre-existing risk model in patients with AHF.

Funding Acknowledgement

Type of funding sources: Foundation. Main funding source(s): Cardiovascular Research Fund

Predicting new-onset heart failure hospitalization of patients with atrial fibrillation: development and external validations of a risk score

Background

Atrial fibrillation (AF) is a well-known risk factor for heart failure (HF), and HF development as a complication of AF is associated with a decline in the quality of life and poor prognosis. However, unlike thrombotic events, incidence of HF in patients with AF has not changed for decades, and a preventive strategy has yet to be developed.

Purpose

We sought to develop a risk model for new-onset HF admission in patients with AF and without a history of HF. Additionally, we attempted to externally validate the developed risk model.

Methods

We utilized two multicenter, prospective, observational registries of AF and analyzed the patients without a history of AF. One of which is defined as a derivation cohort, which included 2,857 patients, and the other is defined as a validation cohort, which included 2,516 patients. We developed a risk model by selecting variables with regularized regression and weighing coefficients by Cox regression analysis with the derivation cohort. The external validity was tested in the validation cohort.

Results

During the follow-up period, 148 patients (5.2%) in the derivation cohort and 104 patients (4.1%) in the validation cohort developed HF during the median follow-up period of 1,396 (interquartile range [IQR]: 1,078–1,820) days and 1,168 (IQR: 844–1,309) days, respectively. In the derivation cohort, four predictors (age, hemoglobin, serum creatinine, and log-transformed brain natriuretic peptide) were identified as potential risk factors for HF development. The developed risk model showed good discrimination and calibration in both the derivation (area under the curve [AUC], 0.77 [95% confidence interval (CI) 0.73–0.81]; Hosmer-Lemeshow test, P=0.257) and validation cohorts (AUC: 0.76 [95% CI 0.72–0.81]; Hosmer-Lemeshow test, P=0.475). Considering death not due to HF as a competing risk, the cumulative incidence curves for HF admission stratified by the risk score were generated, which showed higher HF hospitalization rate for the higher risk score categories.

Conclusion

The newly developed risk model with four readily available clinical characteristics and biomarkers performed well in the prediction of new-onset HF admission of patients with AF in both derivation and validation cohort.

Funding Acknowledgement

Type of funding sources: None.

Clinical impact of novel pericoronary adipose tissue measurement on ECG-gated non-contrast chest CT scan

Background

Pericoronary adipose tissue (PCAT) quantified from coronary computed tomography angiography (CCTA) is a new predictor of CT-derived high-risk plaque (HRP) and adverse cardiac events. There has been no report investigating the method to assess PCAT from non-contrast CT so far. In this present study, we developed a brand-new method to quantify the value of PCAT from electrocardiogram (ECG)-gated non-contrast CT (NC-PCAT).

Purpose

To develop a brand-new method to quantify NC-PCAT accurately, and evaluate its prognostic value.

Methods

We retrospectively studied two independent cohorts of patients undergoing CCTA and ECG-gated non-contrast CT for clinical indication of coronary artery disease (CAD). For former cohort of consecutive 300 patients, we validated the agreement between the NC-PCAT and PCAT, and evaluated the association between NC-PCAT and the prevalence of HRP. For latter cohort of consecutive 333 patients, we dichotomized them into two groups with median NC-PCAT, and assessed the prognostic value of NC-PCAT. To quantify NC-PCAT, we placed 15x15mm region of interest at epicardial fat tissue dorsally adjacent to right coronary ostium in axial slice of ECG-gated non-contrast CT, and defined NC-PCAT as the mean CT value of each 1x1mm pixel there. PCAT was quantified from CCTA using conventional method as described in former researches. Primary endpoint was defined as major adverse cardiac events (MACE), composite of all-cause death and non-fatal myocardial infarction. HRP was defined as coronary artery plaque which has two or more following features; positive remodeling, low attenuation, spotty calcification, and napkin-ring sign.

Results

NC-PCAT was well-correlated with PCAT (r=0.68, p<0.0001). In former cohort, we found HRP in 34 (11.3%) patients. In multivariable logistic regression analysis, higher NC-PCAT (OR 1.06, 95% CI 1.03–1.10, p=0.0001), coronary artery calcium score (CACS) (OR 1.01 per 10 CACS increase, 95% CI 1.00–1.02, p=0.013), and current smoking (OR 2.58, 95% CI 1.03–6.49, p=0.044) were independent predictors of the prevalence of HRP. Among patients with CACS more than zero (n=193), NC-PCAT (OR 1.06, 95% CI 1.03–1.10, p=0.0002), current smoking (OR 3.02, 95% CI 1.17–7.82, p=0.027), and male (OR 2.81, 95% CI 1.06–7.48, p=0.028) were independent predictors of the prevalence of HRP, whereas CACS was not (p=0.15). In latter cohort, the median duration of follow-up was 2.9 years (IQR 1.9–3.9), and 16 (4.8%) cases of MACE were identified. The cumulative incidence of MACE was significantly higher in high NC-PCAT group. Multivariable cox hazard regression analysis revealed that higher NC-PCAT was an independent predictor of primary endpoint, even after adjustment for sex and age (HR 4.28, 95% CI 1.20–12.52, p=0.012).

Conclusions

There was a positive correlation between NC-PCAT and PCAT. Higher NC-PCAT is significantly associated with not only the prevalence of HRP, but also worse clinical outcome.

Funding Acknowledgement

Type of funding sources: None.

Determination of physiological cardiac myosin-binging protein levels (cMyc) in healthy populations

Background

Cardiac myosin–binding protein C (cMyC) is a cardiac-restricted protein that has more abundant, rapid release and clearance kinetics than cardiac troponin. The current ESC guideline suggests the cMyC may provide value as an alternative to cardiac troponin. The 99th percentile value is universally endorsed as the reference cut off to aid in the diagnosis of acute myocardial infarction (AMI), however, none of the report of healthy population of cMyC.

Purpose

The aim of this study was to evaluate the distribution of cMyC values in healthy subjects.

Methods

We used two cohorts in this retrospective study. 1) Healthy subjects; a total of 500 subjects (250 men and 250 women) who had annual health examinations in 2012 in the area of Kamigoto, a suburb of Nagasaki city in Southern Japan were enrolled. All participants showed none of abnormal findings including cell blood counts, chemical analysis, liver function tests, general urine tests, occult blood tests of stool, barium swallow, mammography for women, abdominal ultrasound sonography, and electrocardiogram. All blood samples were obtained in a fasting state in the morning. 2) Chest pain subjects; we collected samples from 250 subjects including 50 with non-ST elevation myocardial infarction visited admitted to a university hospital for measurement of high-sensitivity troponin T and coronary artery assessment by coronary angiography. We measured cMyC level in both cohorts by HISCL™-800 system (Sysmex corporation, Japan). The assay has a limit of detection of 0.5 ng/L and a lower limit of quantification of 1.3 ng/L.

Result

In healthy subjects, median age (IQR) was 44 (20, 82) in men and 50 (23, 91) in women. The 99th percentile of cMyC was 27.3 ng/L, which was around one-third lower than that in previous report (87 ng/L). In chest pain subjects, the concentrations of cMyC at presentation were significantly higher in those with versus without AMI (median, 66 ng/L versus 10 ng/L, P<0.001). Discriminatory power for AMI, as quantified by the area under the receiver-operating characteristic curve (AUC), was comparable for cMyC (AUC, 0.85 (95% CI 0.79–0.91) and hs-cTnT (AUC, 0.81 (95% CI 0.76–0.88)).

Conclusion

We defined the normal range of cMyC in healthy Japanese subjects. The level of cMyC at presentation provides discriminatory power comparable to hs-cTnT in the diagnosis of AMI. To determine the physiological value of a biomarker may be necessary to evaluate enough information about their health status.

Funding Acknowledgement

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): Grant-in-Aid for Scientific Research

Comparison of clinical effect of living alone between urban area and rural area in patient with acute coronary syndrome

Background and objective

Living alone is reported as an independent risk factor for worse clinical outcomes after percutaneous coronary intervention (PCI) for acute coronary syndrome (ACS). Manifestations of psychological stress such as depression and anxiety in patients living alone is thought to be associated with subsequent cardiovascular events. The impact of living alone on the psychological factors of patients may be differ depending on their living environment. However, comparison of the effects of living alone in different living environment on the prognosis of patients with ACS has not been reported.

Purpose

The aim of the present study was to compare the clinical effect of living alone on clinical outcomes in patients with ACS between urban area and rural area.

Methods

Data from a multi-center, observational study of consecutive patients who underwent emergency PCI for ACS between January 2012 and December 2016 were analyzed. The primary endpoint was major adverse cardiac and cerebrovascular events (MACCE). MACCE was defined as composite of cardiovascular death, ACS, and stroke.

Results

In this study, 1349 patients were enrolled and divided into two population according to their living environment: urban area population (n=417), and rural area population (n=932). In urban area population, 87 patients (20.9%) were living alone, and 330 (79.1%) were living together. In rural area population, 169 (18.1%) were living alone, and 763 (81.9%) were living together. There are no significant differences in baseline characteristics between the living alone group and the living together group in both urban area population and rural area population. During a median follow-up period of 2.1 years, Kaplan-Meier curves showed the living alone group had higher risk of MACCE than the living together group in urban area population (log-rank, p=0.01). On the other hands, there are no significant differences in the incidences of MACCE between two groups in rural area population (p=0.86). After adjustment for other covariates, the living alone was significantly associated with MACCE (hazard ratio [HR], 2.83; 95% confidential interval [CI], 1.16–6.91; p=0.02) compared with the living together group in urban area population. However, in rural area population, the living alone group was not significantly associated with MACCE (HR, 1.02; 95% CI, 0.66–1.57; p=0.92) compared with the living together group.

Conclusion

Living alone was significantly associated with worse clinical outcomes after emergency PCI of ACS in urban area but not in rural area.

Funding Acknowledgement

Type of funding sources: None. Figure 1

Comparison of clinical outcomes between percutaneous coronary intervention for the de novo lesion versus in-stent restenosis lesion

Background and objective

Percutaneous coronary intervention (PCI) with metallic coronary stent (bare-metal stents [BMS] and drug-eluting stents [DES]) implantation is most frequently performed therapeutic procedures for coronary artery disease. In-stent restenosis (ISR) is a critical drawback of metallic coronary stents. Incidence of ISR has been reported in up to 30% after BMS implantation. The use of DES has greatly reduced the proportion of restenosis compared with the BMS. However, ISR still remains the primary concern after PCI even in the contemporary DES era, and thought to be associated with worse clinical outcomes. However, comparative data on ISR and de novo lesions are rare.

Purpose

The aim of the present study was to compare the clinical outcomes after PCI for the de novo lesion and the ISR lesion.

Methods

We performed a retrospective analysis of patients who underwent PCI between 2013 and 2020. The incidences of major adverse cardiac and cerebrovascular events (MACCE) and all-cause death were evaluated. MACCE was defined as composite of cardiovascular death, non-fatal myocardial infarction, and stroke.

Results

In this study, 1538 patients were enrolled and divided into two groups: PCI for de novo lesion group (n=1258, 81.8%), and PCI for ISR lesion group (n=280, 18.2%). Patients in the ISR lesion group were significantly older and had higher prevalence of hypertension, diabetes mellitus, dyslipidemia and chronic kidney disease than patients in the de novo lesion group. During a median follow-up period of 1.9 years, Kaplan-Meier curves showed no significant differences in the incidences of MACCE (log-rank, p=0.86) and all-cause death (p=0.84) between two groups. After adjustment for other covariates, PCI for ISR lesion were not significantly associated with MACCE (hazard ratio [HR], 1.10; 95% confidential interval [CI], 0.61–1.97; p=0.76) and all-cause death (HR, 0.93; 95% CI, 0.56–1.56; p=0.79)

Conclusion

PCI for the ISR lesion was not associated with worse clinical outcomes compared with PCI for the de novo lesion.

Funding Acknowledgement

Type of funding sources: None.

Optimal measurement location of on-site based CT-derived FFR on midterm prognosis

Background

Fractional Flow Reserve (FFR) derived from coronary computed tomography angiography (CCTA) enables anatomical and hemodynamical assessment of coronary artery disease. CT-FFR, which can be acquired on-site workstation using fluid structure interaction during the multiple optimal diastolic phase, has an incremental diagnostic value over conventional CCTA. However, few studies are focused on investigating the appropriate measurement location of CT-FFR, considering the prognosis, using CCTA as a standalone modality.

Purpose

The aim of this study is to assess the clinical impact on CT-FFR with an appropriate measurement.

Methods

A total of 370 consecutive patients who underwent CCTA in a single-heartbeat scan with a phase window of 70% to 99% of the R-R interval, showing 50–90% stenosis of at least one major epicardial vessel measuring ≥1.8 mm in diameter on CCTA were retrospectively analyzed and followed during a median follow up 2.9 years. CT-FFR values were measured at three points: 1, 2 cm distal to a target lesion (CT-FFR1cm, 2cm) and the vessel terminus (CT-FFRlowest), and a CT-FFR value ≤0.80 was considered abnormal. The endpoint was MACE, a composite of cardiac death, non-fatal MI, and unplanned revascularization.

Results

The incidence of MACE occurred in 8.4% (31/370) of the whole patients, including four cardiac deaths, ten all cause deaths, two non-fatal MI, and twenty unplanned revascularization. The Kaplan-Meier survival analysis demonstrated a significantly higher cumulative MACE rate in patients with positive CT-FFR1cm and 2cm than those with negative CT-FFR1cm and 2cm, while there was no significant difference between negative and positive in CT-FFRlowest, among patients with negative CT-FFR1cm and 2cm (Figure 1). Among 221 patients, who did not perform early revascularization within 90 days from CCTA, there was no significant difference in CT-FFRlowest in the incidence of MACE. In contrast, the risk of MACE was significantly higher in both positive CT-FFR1cm and CT-FFR2cm (Figure 2).

Conclusion

From a view point of clinical outcome for patients with moderate to severe stenosis on CCTA, a CT-FFR value when measured at 1-to-2 cm distal to a target lesion could be feasible for the deferral of unnecessary invasive coronary angiography safely. Moreover, CT-FFR1–2cm showed better risk stratification measurement rather than CT-FFRlowest, based on future adverse cardiac event.

Funding Acknowledgement

Type of funding sources: Private company. Main funding source(s): Canon Medical Systems Corporation Kaplan-Meier 1Kaplan-Meier 2

The relationship among extent of lipid-rich plaque, factors associated with a reduction of lipid-rich plaque and late lumen loss: a near-infrared spectroscopy and intravascular ultrasound study

Background

Near-infrared spectroscopy (NIRS) and intravascular ultrasound (IVUS) are useful imaging modalities to identify lipid-rich plaque (LRP) which is associated with an increased risk of future cardiovascular events in individuals undergoing PCI. Pathological studies have raised concerns that treating LRP with stents may impair vascular healing. However, the impact of stent implantation to LRP lesions was less known. Moreover, little information is available about changes in the extent of LRP at before and after PCI.

Purpose

The aim of this study was to investigate changes in LRP by NIRS between pre- and post-stent implantation, and to evaluate an association among impact of LRP by NIRS at pre- and post-stenting and late lumen loss (LLL) by angiography.

Methods

We studied 175 lesions in 149 patients who underwent PCI under NIRS-IVUS guidance and follow-up angiography at 8-month later from 2017 to 2020. Plaque characteristics on IVUS, the extent of LRP [defined as a long segment with a 4-mm maximum lipid core burden index (maxLCBI4mm)] on NIRS, and quantitative coronary angiography measurements were analyzed. We evaluated a change of the extent of LRP between pre- and post-stenting at index PCI procedure, and association between the extent of LRP and a 8-month LLL at follow-up coronary angiography. A large LRP was defined as maxLCBI4mm>400 at pre-stenting.

Results

Mean age was 64.5 years old, and 123 (82%) patients were male. The prevalence of large LRP was 51% and median plaque burden at minimum lumen area was 81%. The extent of LRP at culprit lesion significantly decreased from pre- to post-stenting (median maxLCBI4mm [interquartile range (IQR)]: 407 [199, 580] to 133 [13, 319], p<0.001) (Figure 1). In multivariable liner regression analysis, independent predictors for the reduction of LRP were a pre-stenting LRP (β coefficient = −57.0, 95% confidence interval (CI) [−65.1 to −48.8], p<0.001) and plaque burden (β coefficient = −30.0, 95% CI [−56.6 to −3.4], p<0.001), respectively. On the other hands, patient comorbidities, lipid profile and inflammatory markers were not associated with the reduction of LRP (all p>0.05). Median LLL at follow-up angiogram was 0.17 [0.07–0.35] mm. Both the extent of pre- and post-stenting LRP were not associated with LLL (r=0.018, p=0.80 and r=0.022, p=0.76, respectively) (Figure 2). In addition, there was no significant difference in LLL between the post-stenting large and non-large LRP (median [IQR] 0.18 [0.08–0.35] vs. 0.17 [0.07–0.35]; P=0.95).

Conclusions

This study showed coronary stent implantation significantly reduced the NIRS-derived LRP in patients undergoing PCI. Although the extent of pre-stenting LRP and IVUS plaque burden predicted the reduction of LRP, the extent of pre- and post-stenting LRP were not associated with LLL. These findings suggest that stent implantation for LRP, even in a large LRP, is safe and does not affect LLL.

Funding Acknowledgement

Type of funding sources: None. Figure 1. Scatter plotsFigure 2. CENTRAL Figure

Coronary lipid-rich plaque characteristics with acute coronary syndrome and chronic coronary syndrome: a near infrared spectroscopy and intravascular ultrasound study

Background

Asians have a much lower incidence of adverse coronary events than Caucasians, and the characteristics of vulnerable plaque might be different among the ethnics.

Purpose

The aim of this study was to investigate the clinical characteristics of lipid-rich plaque (LRP) in the Asian population and we also aimed to distinguish the characteristics of an acute coronary syndrome (ACS) culprit lesion and a chronic coronary syndrome (CCS) culprit lesion. Furthermore, we evaluated the association between lipid core burden index (LCBI) and cardiovascular risk factors, lipid profiles, and inflammatory biomarkers, as determined in vivo by near infrared spectroscopy intravascular ultrasound (NIRS-IVUS) imaging in patients undergoing percutaneous coronary intervention (PCI).

Methods

We evaluated 207 patients (ACS, n=75; CCS, n=132) who underwent PCI under NIRS-IVUS. Plaque characteristics and the extent of LRP [defined as a long segment with a 4-mm maximum LCBI (maxLCBI4mm)] on NIRS in de-novo culprit and non-culprit segments were analyzed.

Results

The mean age was 65 years old and 82% of patients were male. The ACS culprit lesions had a significantly higher maxLCBI4mm (median [interquartile range (IQR)]: 533 [385–745] vs. 361 [174–527], p<0.001) than the CCS culprit lesions. Whereas, no significant difference was seen in maxLCBI4mm between ACS and CCS non-culprit lesion segments (246 [53, 342] vs. 185 [37, 350], p=0.47) (Figure 1). Receiver-operating characteristic analysis showed that the NIRS maxLCBI4mm could distinguish the ACS culprit segment from the CCS culprit segment, with a sensitivity of 73% and a specificity of 69% (c-statistic = 0.69; p<0.001, cut-off value of max LCBI4mm = 408) (Figure 2). On multivariate logistic analysis, a large LRP (defined as maxLCBI4mm ≥400) was the strongest independent predictor of the ACS culprit segment (odds ratio, 3.87; 95% confidence interval, 1.95–8.02). In non-culprit segments, 19.8% of patients had at least one large LRP without a small lumen. No significant correlation was found between the extent of LRP and circulating lipid profiles and inflammatory makers biomarkers (hs-CRP, IL-6, TNF-α) in both the culprit and non-culprit lesion segments, whereas the extent of LRP was positively correlated with IVUS plaque burden (r=0.24, p<0.001).

Conclusions

We confirmed that NIRS-IVUS plaque assessment could be useful to differentiate ACS from CCS culprit lesions, and that a threshold maxLCBI4mm ≥400 was clinically suitable in Japanese patients. No systemic surrogate markers were found to be associated with the extent of LRP by NIRS in culprit and non-culprit segments. Consequently, we believe that direct intravascular evaluation of coronary plaque characteristics remains important for identification of high-risk LRP.

Funding Acknowledgement

Type of funding sources: None. Figure 1. The difference of maxLCBI4mmFigure 2. ROC curve

Obesity associated pro-fibrotic protein augments fibrosis in heart

 

Chronic sterile inflammation in visceral fat has causal roles for systemic metabolic disorders in obesity. Inflamed visceral adipose tissue secretes pro-inflammatory adipokines, and this contributes to tissue remodeling under a metabolically stressed condition. Various kinds of white adipokines are broadly studied, however, roles of brown adipose tissue (BAT) derived adipokines (BATokine) remain to be explored. In this project, we tried to characterize pathogenic role of BATokine in obesity related fibrotic disorders, especially focusing on heart failure with preserved ejection fraction (HFpEF). For this purpose, we analyzed two sets of DNA microarray data, and identified an obesity associated pro-fibrotic protein (OAFP) as a possible pathogenic BATokine. Our biobank studies showed OAFP increased in patients with diastolic dysfunction, and E/e' analyzed with cardiac echo increased in direct proportion to circulating OAFP level in humans. We generated dietary obese mice model, and found OAFP increased both in BAT and circulation. We generated a murine systemic or BAT specific OAFP knockout (KO) models, and found that obesity-induced diastolic dysfunction ameliorated in these models. Cardiac fibrosis was also suppressed by genetic depletion of OAFP. We found OAFP increased in circulation in aged humans and mice, and studies in chronologically aged mice showed this molecule increased in BAT with aging. Our results indicate that OAFP is secreted predominantly from BAT, and mediates pathogenic roles by augmenting cardiac fibrosis in dietary obesity or aging. Suppression of OAFP may become a therapy for HFpEF.

Funding Acknowledgement

Type of funding source: None

The crucial roles of coagulation factors in inducing brown adipose tissue dysfunction and systemic metabolic disorder in obesity

 

The prevalence of obesity is increasing worldwide. Obese individuals are predisposed to cardio-metabolic disorders. Brown adipose tissue (BAT) is an active metabolic organ abundant with mitochondria, and studies suggest a potential role of BAT in the maintenance of metabolic health in rodents and humans. Metabolic stress causes BAT dysfunction, but the underlying mechanisms are largely unknown. Coagulation factor Xa (FXa) is critically involved in a coagulation cascade, and it is also known to mediate biological effects by the activation of protease-activated receptor (PAR)-signaling. Accumulating evidence shows that PAR1 contributes to tissue remodeling in cardiovascular system. Analyzing deposited microarray data, we found transcripts for coagulation factors including factor VII (F7), factor X (F10), and PAR1 receptor were increased in BAT from obese mice. Here we show a previously unknown role of FXa-PAR signaling in promoting BAT dysfunction and systemic metabolic disorder in a murine dietary obese model.

Imposing a high fat diet (HFD) on C57BL/6NCr mice led to a marked increase in tissue factor (TF), coagulation factor VII and FXa in BAT. TF-FVIIa (activated form of FVII)-FXa complex is known to activate PAR1, and we found a significant increase in PAR1 expression in BAT upon metabolic stress. Administration of a FXa inhibitor ameliorated BAT whitening, improved thermogenic response and systemic glucose intolerance upon dietary obesity. Fxa inhibition reduced reactive oxygen species (ROS) level in BAT. In contrast, administration of warfarin did not show any phenotype in BAT. BAT specific TF and PAR1 over-expression model showed significant whitening of this tissue, which was associated with systemic glucose intolerance. We generated BAT specific PAR1 KO mice. BAT-PAR1 KO mice exhibited re-browning of BAT along with reduced ROS level in this tissue. In BAT-PAR1 KO mice, glucose intolerance and thermogenic response under a metabolically stressed condition were ameliorated. In differentiated brown adipocytes, FXa markedly increased mitochondrial ROS and reduced mitochondrial membrane potential. Inhibition of PAR1 ameliorated FXa-induced mitochondrial ROS production and reduction in membrane potential. We also found that plasma FXa level did not increase in obese mice as well as in obese individuals. These results suggest the previously unknown role of coagulation systems in promoting BAT dysfunction, leading to systemic metabolic disorders. Maintenance of BAT homeostasis through the suppression of FXa-PAR1 signaling would become a new therapeutic target for obesity and diabetes.

Funding Acknowledgement

Type of funding source: None

Elimination of senescent cells targeting Senescence associated glycoprotein (SAGP) improved the ageing-associated diseases and extended the lifespan

 

Cellular senescence entails an irreversible growth arrest and a pro-inflammatory secretory phenotype, which contributes to aging-associated disorders such as atherosclerosis and diabetes, however, underlying mechanisms are largely unknown. In this study, we identified a novel protein, senescence-associated glycoprotein (SAGP), as a biomarker of cellular senescence and we also found that elimination of senescent cells targeting SAGP attenuated aging-associated disorders such as atherosclerosis, diabetes and frailty.

First, we identified that SAGP as a senescent marker by microarray analysis of senescent human endothelial cells compared with young endothelial cells. The expression of SAGP was significantly increased in the aorta of chronological aging mice and ApoE-knockout mice. Then we measured SAGP expression in the patients registered in our hospital and found that mean SAGP expression was significantly higher in patients with atherosclerotic diseases compared to patients without atherosclerotic diseases. These data suggest that SAGP would become the novel marker of cellular senescence and/or aging-associated disorders.

We found SAGP co-localized with lysosome and bound to V-ATPase, proton pump in the acid organelles such as lysosome. The electron microscopy analysis revealed that the dysfunctional lysosomes were accumulated in SAGP knockdown endothelial cell. The genetic deletion of SAGP resulted in the increase of lysosomal pH and the suppression of mitochondrial autophagy, mitophagy. And this associated with the high level of mitochondrial reactive oxygen species (ROS) and promoted premature senescence in human endothelial cells. These data suggest that SAGP was induced by the lysosomal stress in the senescent cells to protects senescent cells by maintaining the lysosomal homeostasis.

Recently, it is reported that elimination of senescent cells (senolysis) reversibly improved pathological aging phenotypes and also extended the lifespan. We established senolytic therapy targeting SAGP. We generated SAGP-DTR (diphtheria toxin receptor) transgenic mice, in which we could eliminate the SAGP- positive senescent cells using DT (diphtheria toxin). We found elimination of SAGP positive senescent cells significantly reduced the atherosclerotic plaque burden in the aorta of ApoE-KO mice and improved the glucose metabolism of dietary obese mice, indicating that SAGP could be a useful target for senolytic therapy. For clinical implication, we then developed a cytotoxic vaccine targeting SAGP. Treatment with SAGP vaccine successfully eliminated SAGP positive senescent cells and attenuated atherosclerosis and metabolic dysfunction. Surprisingly, administration of SAGP vaccine to Zmpste24-KO mice, premature aging mice, extended the lifespan. These data indicate that targeting SAGP-positive cells could be a novel strategy for senolytic therapy.

Effect of SAGP vaccine

Funding Acknowledgement

Type of funding source: Public grant(s) – National budget only. Main funding source(s): Grant-in-Aid for Scientific Research by Japan Society for the Promotion of Science (JSPS)

Cardiac mitofusin-1 is declined in non-responding patients with idiopathic dilated cardiomyopathy

Background/Introduction

Mitochondria are dynamic regulators of cellular metabolism and homeostasis. The dysfunction of mitochondria has long been considered a major contributor to aging and age-related diseases. The prognosis of severe heart failure is still unacceptably poor and it is urgent to establish new therapies for this critical condition. Some patients with heart failure do not respond to established multidisciplinary treatment and they are classified as “non-responders”. The outcome is especially poor for non-responders, and underlying mechanisms are largely unknown.

Purpose

Studies indicate mitochondrial dysfunction has causal roles for metabolic remodeling in the failing heart, but underlying mechanisms remain to be explored. This study tried to elucidate the role of Mitofusin-1 in a failing heart.

Methods

We examined twenty-two heart failure patients who underwent endomyocardial biopsy of intraventricular septum. Patients were classified as non-responders when their left-ventricular (LV) ejection fraction did not show more than 10% improvement at remote phase after biopsy. Fourteen patients were classified as responders, and eight as non-responders. Electron microscopy, quantitative PCR, and immunofluorescence studies were performed to explore the biological processes or molecules involved in failure to respond. In addition to studies with cardiac tissue specific knockout mice, we also conducted functional in-vitro studies with neonatal rat ventricular myocytes.

Results

Twenty-two patients with IDCM who underwent endomyocardial biopsy were enrolled in this study, including 14 responders and 8 non-responders. Transmission electron microscopy (EM) showed a significant reduction in mitochondrial size in cardiomyocytes of non-responders compared to responders. Quantitative PCR revealed that transcript of mitochondrial fusion protein, Mitofusin-1, was significantly reduced in non-responders. Studies with neonatal rat ventricular myocytes (NRVMs) indicated that the beta-1 adrenergic receptor-mediated signaling pathway negatively regulates Mitofusin-1 expression. Suppression of Mitofusin-1 resulted in a significant reduction in mitochondrial respiration of NRVMs. We generated left ventricular pressure overload model with thoracic aortic constriction (TAC) in cardiac specific Mitofusin-1 knockout model (c-Mfn1 KO). Systolic function was reduced in c-Mfn1 KO mice, and EM study showed an increase in dysfunctional mitochondria in the KO group subjected to TAC.

Conclusions

Mitofusin-1 becomes a biomarker for non-responders with heart failure. In addition, our results suggest that therapies targeting mitochondrial dynamics and homeostasis would become next generation therapy for severe heart failure patients.

Funding Acknowledgement

Type of funding source: None

A novel senolytic drug, seno-7284 ameliorates aging phenotype and age-related cardiometabolic diseases

Background

Cellular senescence occurs as a result of various genotoxic stresses and it plays a pivotal role in aging and age-related disorders. Recently, it was shown that elimination of senescent cells, so-called “senolysis” has the potential to become a promising novel therapy for age-related disorders in several mice models including cardiovascular diseases. However, there is no senolytic drug available in clinical settings currently.

Purpose

The present study was aimed to identify a novel senolytic reagent effective for cardiometabolic disease among compounds already available in clinical settings. Here we demonstrate that a compound called “seno-7284” exhibits senolytic effect in murine models of type 2 diabetes, atherosclerosis, progeroid and chronological aging.

Methods

We generated diet-induced obesity/diabetic mice model by imposing high-fat diet from 4-week-old for two months, atherosclerosis mice model by imposing western diet to ApoE homozygous knockout mice (ApoE-KO mice) from 4-week-old for 3 months. We administered seno-7284 mixed in the diet (0.03% w/w) to each mouse model for 1, 2 or 4 weeks. For the analysis, we carried out some physiological examinations including glucose tolerance test (GTT) and insulin tolerance test (ITT), then harvested tissue samples and took them to molecular biological analysis including real-time PCR, western blotting, RNA-sequence, etc. We also generated Zmpste24 homozygous knockout mice (Zmpste24-KO mice) as a progeroid mice model to measure their lifespan. Seno-7284 was administered to Zmpste24-KO mice from 12-week-old to the end of life. We also administrated seno-7284 to chronological aged mice at 1-year-old for 20 weeks and their physical function was examined with rotarod running test and hand-grip test.

Results

Seno-7284 reduced the accumulation of senescent cells in visceral adipose tissue of dietary obese mice as senescence-associated beta-galactosidase (SA-beta-gal) staining exhibits (Figure 1a). This effect results in ameliorating insulin tolerance (Figure 1b) and adipose tissue inflammation after 4-week administration of seno-7284. We also found administrating Seno-7284 for two weeks also reduced the accumulation of senescent cells in the atherosclerotic lesion in the aorta of ApoE-KO mice (Figure 1c) and inhibited advancing atherosclerosis (Figure 1d). Surprisingly, seno-7284 significantly improved the lifespan of Zmpste24 KO mice (Figure 1e). Seno-7284 also improved the physical function of chronologically aged mice by administrating it from 1-year-old for 20 weeks (Figure 1f). In-vitro studies didn't exhibit seno-7284 kills senescent cells directly, but further analysis including RNA-seq or metabolomic analysis speculated that seno-7284 stimulates endogenous senolytic function of NK-cells and CD8+ T-cells.

Conclusion

Our results indicate that seno-7284 would become a promising senolytic drug that exhibits novel therapeutic machinery for aging and age-related cardiometabolic diseases.

Figure 1

Funding Acknowledgement

Type of funding source: Public grant(s) – National budget only. Main funding source(s): Grant-in-Aid for Scientific Research (KAKENHI) C, Niigata University Tsukada medical research grant

Circulating pro fibrotic protein promotes fibrosis in liver

Background/Introduction

Non-alcoholic steatohepatitis (NASH), driven by the obesity epidemic, has become the most common form of liver disease. Inflamed visceral adipose tissue secretes pro-inflammatory adipokines that are causal for systemic metabolic disorders. Role of adipokines in NASH, especially those from brown adipose tissues (BATokine) remain unclear.

Purpose

To show the pathogenic role of BATokine in NASH.

Methods

To identify and characterize the pathological roles of pro-fibrotic BATokine, we generated a murine obese NASH model by imposing a high fat diet in C57BL6/NCr mice, and murine systemic or BAT specific knockout (KO) models. We also conducted functional in-vitro studies with differentiated brown adipocytes.

Results

Analyzing two sets of DNA micro array data with bioinformatics, we identified a secreted form pro-fibrotic protein (sPFP) expressed in dysfunctional brown adipose tissues (BAT) in mice. Testing our biobank samples, we found this protein increased in plasma of NASH patients. We generated a murine obese NASH model by imposing a high fat diet in C57BL6/NCr mice for 9–10 months since 4 weeks of age, and found that sPFP is produced predominantly by BAT. In this model, we also found that sPFP increased in plasma. We generated a murine systemic or BAT specific sPFP knockout (KO) models and found that liver fibrosis ameliorated in these models. We also suppressed circulating sPFP with a peptide vaccine targeting this molecule, and found that sPFP vaccination therapy inhibited liver fibrosis. Next, we generated sPFP gain of function (GOF) model by the administration of plasmid encoding sPFP into skeletal muscle. Liver fibrosis augmented in sPFP-GOF model, and these results suggested that sPFP has causal role for the progression of fibrotic response in liver. In vitro studies with differentiated brown adipocytes showed that metabolic stress increased c-Fos in nuclear, and this was causal for an increase in sPFP level.

Conclusions

Our results suggest that one of the BATokines, sPFP, contributes for the progression of fibrotic responses in obese-NASH model. Inhibition of sPFP may become a therapy for NASH or obesity related fibrotic disorders.

Funding Acknowledgement

Type of funding source: None

5892Elimination of cells expressing Senescence associated glycoprotein (SAGP) attenuates the atherosclerotic diseases

Cellular senescence is defined as a state of irreversible growth arrest and is accompanied by changes of both cell morphology and gene expression. Although accumulation of senescent vascular endothelial cells impair the vessel homeostasis and promote atherosclerotic diseases, underlying mechanisms are largely unknown. In this study, we identified a novel protein, senescence-associated glycoprotein (SAGP), as a biomarker of cellular senescence and we found modulation of SAGP or elimination of senescent cells targeting SAGP would become a novel therapy for atherosclerotic diseases.

We found that SAGP expression was significantly increased in human endothelial cells undergoing replicative senescence compared with young endothelial cells. We also found SAGP expression in aorta was significantly increased both in chronological aging mice or ApoE knockout mice. Furthermore, we measured SAGP expression in patients registered in our hospital and found that mean SAGP expression was significantly higher in patients with atherosclerotic diseases compared to patients without atherosclerotic diseases.These data suggest that SAGP would become a novel cellular senescence and/or atherosclerotic disease marker.

Genetic deletion of SAGP resulted in high level of mitochondrial reactive oxygen species (ROS) and promoted premature senescence in human endothelial cells. And this associated with suppression of mitochondrial autophagy, mitophagy. We found SAGP co-localized with lysosome by immunocytochemistry. In addition, the electron microscopy analysis revealed that the dysfunctional lysosomes were accumulated in SAGP knockdown endothelial cell, suggesting that SAGP maintain lysosomal homeostasis.

Next, wegenerated ApoE-KO/ SAGP overexpression mice and found that atherosclerotic plaque burden was attenuated in these double-transgenic mice. In contrast, SAGP/ApoE double knockout mice showed progression in atherosclerosis. These data suggest that modulation of SAGPwould become a new therapeutic target for atherosclerotic diseases.

SAGP vaccine

Recently, it is reported that elimination of senescent cells (senolysis) reversibly improved pathological aging phenotypes and also extended the lifespan. We have taken another approach for atherosclerotic diseases, senolytic therapy targeting SAGP. We generated SAGP-DTR (diphtheria toxin receptor) transgenic mice, in which we could eliminate the SAGP- positive senescent cells using DT (diphtheria toxin). We found elimination of SAGP positive senescent cells significantly reduced the atherosclerotic plaque burden, indicating that SAGP would become a useful target for senolytic therapy. We then developed a cytotoxic vaccine targeting SAGP. Treatment with SAGP vaccine successfully eliminated SAGP positive senescent cells. Administration of SAGP vaccine to ApoE-KO mice significantly reduced atherogenesis. These data indicate that targeting SAGP-positive cells could become a strategy for senolytic therapy.

P3496Empagliflozin improves cardiac function through the increased production of acetylcarnitine in a murine non-diabetic heart failure model

Background

Empagliflozin is a renal sodium glucose transporter 2 (SGLT2) inhibitor, thereby mediates its anti-diabetic effect via excretion of glucose into urine. EMPA-REG OUTCOME study, the first big randomized control trial of empagliflozin have shown significant reduction of mortality and hospitalization due to heart failure in diabetic patients. This trial hasn't only had a huge impact to cardiovascular field, but also raised a number of questions about underlying mechanisms. It is also uncertain about the efficacy of empagliflozin in non-diabetic heart failure. In this study, we aimed to elucidate the biological effects and its underling mechanism of empagliflozin in a murine non-diabetic heart failure model.

Methods

We generated a heart failure murine model due to left ventricular (LV) pressure overload by performing transverse aortic constriction (TAC) operation to C57BL/6NCr mice. Two weeks after TAC operation we started empagliflozin administration mixed with diet at the ratio of 0.03% w/w. LV function was measured with echocardiography after administration of empagliflozin for two weeks (four weeks after TAC operation) and compared to a littermate control (no treatment) group. Then, heart samples were collected and subjected to further studies including metabolomic analysis. In-vitro studies including Seahorse Extracellular Flux Analyzer were also conducted with differentiated C2C12 cells and neonatal rat ventricular myocytes (NRVM).

Results

We found that empagliflozin treatment (Empa) significantly ameliorated LV systolic dysfunction induced by TAC compared to control group (Con) (figure.A) while heart weight/body weight ratio wasn't reduced. To explore key metabolites that can contribute to improvement of LV function, we conducted metabolomic analysis and found that empagliflozin significantly increased plasma acetylcarnitine level both in sham and TAC groups (figure.B). Previous studies have shown that acetylcarnitine acts as a substrate of acetyl CoA to fuel tricarboxylic acid cycle, and we tested the efficacy of acetylcarnitine for mitochondrial respiration capacity in differentiated C2C12 cells with Seahorse Extracellular Flux Analyzer. This analysis revealed that administration of acetylcarnitine resulted in a significant increase of oxygen consumption reflected by enhancing mitochondrial respiration. Similary, acetylcarnitine also markedly ameliorated impairment of mitochondrial respiration induced by isoproterenol in NRVM.

Conclusion

Our results indicated that empagliflozin has cardioprotective effect in murine heart failure model by enhancing mitochondrial respiration through the increased production of acetylcarnitine. We provide new evidence that empagliflozin would become a promising therapeutic agent to heart failure without diabetes.

5219A novel senolytic drug, seno-7284 ameliorates age-related cardiometabolic diseases

Background

Senescence at cellular level develops with various genotoxic stresses and it plays a pivotal role in aging and age-related disorders. Recently, it was shown that elimination of senescent cells, so called “senolysis” has potential to become a next generation therapy for age-related disorders including cardiovascular diseases, pulmonary emphysema, Alzheimer's diseases, etc. However, currently there is no senolytic agent available in clinical settings.

Purpose

Present study was aimed to identify a novel senolytic agent effective for cardiometabolic diseases in compounds already available in clinical settings. Here we demonstrate a compound called “seno-7284” exhibits senolytic effect in murine models of type 2 diabetes, atherosclerosis and progeroid.

Methods

We generated 1) diet-induced obase and diabetic model by imposing a high fat diet for two months, 2) atherosclerosis mice model by imposing western diet to ApoE homozygous knockout mice (ApoE-KO mice) for three months, and 3) Zmpste24 homozygous knockout mice (Zmpste24-KO mice) as a progeroid mice model. We administrated seno-7284 by mixing it into the diet (0.03% w/w). In one, two or four weeks after the administration of seno-7284 to each mice model, we collected tissue samples for further analyses.

Results

Seno-7284 reduced the accumulation of senescent cells in visceral adipose tissue of dietary obese mice as senescence-associated beta-galactosidase (SA-beta-gal) staining exhibits (Figure a). This effect was associated with the suppression in systemic glucose intolerance (Figure b), and adipose tissue inflammation in four weeks after the administration of seno-7284. Administrating seno-7284 for two weeks also reduced accumulation of senescent cells in atherosclerotic lesion in aorta of ApoE-KO mice (Figure c), and inhibited the progression of atherosclerosis (Figure d). Surprisingly, this drug significantly improved the lifespan of Zmpste24-KO mice by administering it from 12 weeks old. Further analysis including RNA-seq or metabolomic analysis suggested that seno-7284 stimulates endogenous senolytic function of NK cells and CD8+ T cells.

Conclusion

Our results indicate that seno-7284 mediates its biological effects by inducing senolysis in some murine aging models. Seno-7284 would become a promising therapeutic agent for age-related cardiometabolic diseases.

P2591Circulating pro fibrotic protein promotes fibrosis in liver and heart

Analyzing two sets of DNA micro array data with bioinformatics, we identified a secreted form pro-fibrotic protein (sPFP) expressed in dysfunctional brown adipose tissue (BAT) in mice. Testing our biobank samples, we found this protein increased in plasma of non-alcoholic steatohepatitis (NASH) patients or aged individuals. We generated a murine obese NASH model by imposing a high fat diet in C57BL/6NCr mice for 9–10 months since 4 weeks of age, and found that sPFP is produced predominantly by BAT. In this model, we also found that sPFP increased in plasma. We generated a murine systemic sPFP knockout (KO) model and found that liver fibrosis ameliorated in sPFP-KO model. We also suppressed circulating sPFP with a peptide vaccine targeting this molecule, and found that sPFP vaccination therapy inhibited liver fibrosis. Next, we generated sPFP gain of function (GOF) model by the administration of plasmid encoding sPFP into skeletal muscle. Liver fibrosis augmented in sPFP-GOF model, and these results suggested that sPFP has causal role for the progression of fibrotic response in liver. In the obese NASH model, we found that cardiac fibrosis also developed and it ameliorated in sPFP-KO model, indicating that sPFP may have pathological roles for heart failure with preserved ejection fraction (HFpEF) related with age-related disorders. In addition to an increase in circulating sPFP in aged individuals, we found that sPFP increased in BAT of chronological aged mice model. In vitro studies with differentiated brown adipocytes showed that c-Fos upregulated sPFP in transcript level. Our results suggest that sPFP contributes for the progression of fibrotic responses in obese or aged models. Inhibition of sPFP may become a therapy for NASH or HFpEF.

P1613Brown adipose tissue dysfunction has a critical role for the development of heart failure in murine pressure overload model

Prognosis of severe heart failure is unacceptably high, and it is our urgent task to find therapies for this critical condition. It has been reported that low body temperature predicts poor clinical outcomes in patients with heart failure, however, underlying mechanisms and pathological implications are largely unknown. Brown adipose tissue (BAT) was initially characterized as a heat generating organ, and studies suggest that BAT has crucial roles for the maintenance of systemic metabolic health. Here we show that BAT dysfunction develops in a murine thoracic aortic constriction (TAC) model, and has a causal role for promoting pathologies in failing heart. TAC operation led to a significant reduction both in intraperitoneal and subcutaneous temperature. TUNEL-positive cells significantly increased in BAT during left ventricular (LV)-pressure overload, and in-vitro studies with differentiated brown adipocytes suggested that the chronic activation of adrenergic signaling promotes apoptosis in these cells. Gain of BAT function model, generated with BAT implantation into peritoneal cavity, improved thermogenesis and ameliorated cardiac dysfunction in TAC. In contrast, genetic model of BAT dysfunction promoted cardiac dysfunction. Metabolomic analyses showed that BAT dysfunction led to an increase of oxidized choline that promoted metabolic dysfunction in the failing heart. Electron microscope study showed that oxidized choline induced mitochondrial dysfunction in vitro as well as in vivo settings. Extracellular flux analyzerindicated that oxidized choline suppresses oxidative phosphorylation in mitochondria. We found that dilated cardiomyopathy patients have lower body temperature, and confirmed by metabolomic study that both choline and oxidized choline are increased in circulation. Maintenance of BAT homeostasis and suppression of oxidized choline would become a novel therapeutic target for heart failure.

P6578Development of the novel program to diagnose atrial fibrillation using automated blood pressure monitor

Background

Atrial fibrillation (AF) is often asymptomatic and contributes to an increased risk of strokes. The development of proper screening device of AF is unmet medical needs worldwide. Recently, we had reported that multiple measurements using Omron automated blood pressure (BP) monitor with irregular heartbeat detection showed high sensitivity and specificity for AF detection in general cardiac patients, however, this method had limitations in discriminating between AF and other arrhythmias.

Purpose

The aim of this study is to develop a novel program that can accurately diagnose AF by discriminating it from other arrhythmias using the pressure pulse waveform data outputted from Omron automated BP monitor.

Methods

In our previous clinical research, BP measurements were performed 3 times each for 303 general cardiac patients (mean age: 72.2 years, 69.8% male) with recording the real-time single lead ECG, and a total of 909 pressure pulse waveforms were obtained. Among them, 840 pressure pulse waveforms from 280 patients (include 40 AF patients) used for further analysis. We developed a program to analyze and visualize uniquely the characteristics of AF waveform through the autocorrelation-based waveform processing system produced by Melody International Ltd, Kagawa, Japan. All visualized results were judged and classified into Sinus, Non-AF and AF by two individuals blinded to the results. For each patient who obtained 3 results, a two by two contingency table was created and sensitivity, specificity, and accuracy for diagnosing AF were calculated.

Results

Among 840 pressure pulse waveforms, only 21 (2 Sinus and 19 Non-AF) out of 720 Sinus and Non-AF waveforms were judged as AF, and 7 out of 120 AF waveforms were judged as Non-AF. None of AF waveforms was absolutely misjudged as Sinus. In analysis for each patient, when one or more AF judgements were found in 3 waveforms, the diagnosis of AF has sensitivity and specificity of 100% and 95.8%, respectively. When two or more AF judgements were found in 3 waveforms, the diagnosis of AF has sensitivity and specificity of 100% and 97.9%, respectively. In this rule, the diagnostic accuracy of AF reached up to 98.8%, and no sinus patients were misjudged as AF.

Conclusion

The novel program, which applied autocorrelation methods uniquely to analysis of the pressure pulse waveforms recorded by automated BP monitor, showed high sensitivity and high specificity for AF diagnosis in general cardiac patients. This program is expected to be useful for early diagnosis for asymptomatic AF patients.

Acknowledgement/Funding

The present research is supported by a grant through the SCOPE from the Ministry of Internal Affairs and Communications, Japan.

Viral level is an indicator of long-term outcome of hepatitis B virus e antigen-negative carriers with persistently normal serum alanine aminotransferase levels

The association between viral level and the long-term outcomes of hepatitis B virus (HBV) carriers who test negative for hepatitis B virus e antigen (HBeAg) but have persistently normal serum alanine aminotransferase levels (PNALT) remains unclear. We examined hepatocarcinogenesis, hepatitis reactivation, predictive factors and the time course of HBV DNA levels during follow-up in 104 HBeAg-negative Japanese carriers with PNALT. During a mean follow-up period of 6.4 ± 3.4 years, 5 patients (4.8%) had hepatocarcinogenesis and 14 (13.5%) had hepatitis reactivation. At 5 and 10 years, the cumulative rates of hepatocarcinogenesis were 2.4% and 9.9%, while those of hepatitis activation were 13.7% and 15.5%, respectively. An HBV DNA level of ≥5 log10  copies/mL was the sole predictor of hepatocarcinogenesis with a univariate analysis. An HBV DNA level of ≥5 log10  copies/mL and an alanine aminotransferase (ALT) level of >20 to ≤40 IU/L were independent predictors of hepatitis reactivation in a Cox model. Because there was no association between hepatocarcinogenesis and ALT activity, the HBV DNA level was considered an essential predictor. In addition, the baseline HBV DNA level was related to the future level and was not subject to wide fluctuations. Our results showed that an HBV DNA level of ≥5 log10  copies/mL predicts subsequent hepatocarcinogenesis and hepatitis reactivation in HBeAg-negative carriers with PNALT. As the baseline HBV DNA level reflects the future level, appropriate clinical management according to the viral level is expected to decrease future risk.

Effect of heme oxygenase-1 overexpression in two models of lung inflammation

An increasing number of studies implicate heme oxygenase-1 (HO-1) in the regulation of inflammation. Although the mechanisms involved in this cytoprotection are largely unknown, HO-1 and its enzymatic products, carbon monoxide and bilirubin, downregulate the inflammatory response by either attenuating the expression of adhesion molecules and thus inhibiting leukocyte recruitment or by repressing the induction of cytokines and chemokines. In the present study we used genetically engineered mice that express high levels of a human cDNA HO-1 transgene in lung epithelium to assess the effect of HO-1 on lung inflammation. Two separate models of inflammation were studied: hypoxic exposure and lipopolysaccharide (LPS) challenge. We found that both mRNA and protein levels of specific cytokines and chemokines were significantly elevated in response to hypoxia in the lungs of wild-type mice after 2 and 5 days of exposure but significantly suppressed in the hypoxic lungs of transgenic mice, suggesting that inhibition of these cytokines was caused by overexpression of HO-1. However, LPS treatment resulted in a very pronounced increase in mRNA levels of several cytokines in both wild-type and transgenic mice. Despite the high mRNA levels, significantly lower cytokine protein levels were detected in the bronchoalveolar lavage of HO-1 overexpressing mice compared with wild type, indicating that HO-1 leads to repression of cytokines in the airway. These results demonstrate that HO-1 activity operates through distinct molecular mechanisms to confer cytoprotection in the hypoxic and the LPS models of inflammation.

Proteolytic analysis of the FliH/FliI complex, the ATPase component of the type III flagellar export apparatus of Salmonella

The ATPase FliI of the Salmonella type III flagellar protein export apparatus is a 456 amino acid residue cytoplasmic protein consisting of two regions, an N-terminal flagellum-specific region and a C-terminal ATPase region. It forms a complex with a regulatory protein FliH in the cytoplasm. Multi-angle light-scattering studies indicate that FliH forms a homodimer, (FliH)2, and that FliH and FliI together form a heterotrimer, (FliH)2FliI. Mobility upon gel-filtration chromatography gives much higher apparent molecular masses for both species, whereas the mobility of FliI is normal. Sedimentation velocity measurements indicate that both (FliH)2 and the FliH/FliI complex are quite elongated. We have analyzed FliH, FliI and the FliH/FliI complex for proteolytic sensitivity. FliI was degraded by clostripain into two stable fragments, one of 48 kDa (FliI(CL48), missing the first seven amino acid residues) and the other of 46 kDa (FliI(CL46), missing the first 26 residues). Small amounts of two closely spaced 38 kDa fragments (FliI(CL38), missing the first 93 and 97 residues, respectively) were also detected. The FliH homodimer was insensitive to clostripain proteolysis and provided protection to FliI within the FliH/FliI complex. Neither FliI(CL48) nor FliI(CL46) could form a complex with FliH, demonstrating that the N terminus of FliI is essential for the interaction. ATP, AMP-PNP, and ADP bound forms of FliI within the FliH/FliI complex regained sensitivity to clostripain cleavage. Also, the sensitivity of the two FliI(CL38) cleavage sites was much greater in the ATP and AMP-PNP bound forms than in either the ADP bound form or nucleotide-free FliI. The ATPase domain itself was insensitive to clostripain cleavage. We suggest that the N-terminal flagellum-specific region of FliI is flexible and changes its conformation during the ATP hydrolysis cycle.

The role in flagellar rod assembly of the N-terminal domain of Salmonella FlgJ, a flagellum-specific muramidase

The C-terminal half of the Salmonella flagellar protein FlgJ has peptidoglycan hydrolyzing activity and it has been suggested that it is a flagellum-specific muramidase which locally digests the peptidoglycan layer to permit assembly of the rod structure to proceed through the periplasmic space. It was also suggested that FlgJ might be involved in rod formation itself, although there was no direct evidence for this. We purified basal body structures from SJW1437(flgJ) transformed with plasmids encoding various mutant FlgJ proteins and found that these basal bodies possessed the periplasmic P ring but lacked the outer membrane L ring; they also lacked a hook at their distal end. All of these mutant FlgJ proteins had an altered or missing C-terminal domain but had at least the first 151 amino acid residues of the N-terminal domain. Immunoblotting analysis of fractionated cell extracts revealed that a rod/hook export class protein, FlgD, was exported to the periplasm but not to the culture supernatant in these mutants. FlgJ was shown to physically interact with several proteins, and especially FliE and FlgB, which are believed to reside at the cell-proximal end of the rod. On the basis of these results, we conclude that the N-terminal 151 amino acid residues of FlgJ are directly involved in rod formation and that the muramidase activity of FlgJ, though needed for formation of the L ring and subsequent events such as hook formation, is not essential for rod or P ring formation. In contrast, muramidase activity alone does not support rod assembly.

Nifedipine limits infarct size via NO-dependent mechanisms in dogs

OBJECTIVES

Amlodipine increases NO levels in coronary vessels and aorta via bradykinin-dependent mechanisms in vitro. We have previously reported that nifedipine increases cardiac NO levels in the ischemic canine hearts, suggesting that nifedipine may also have protective effects against ischemia and reperfusion injury, because the enhancement of NO production limits infarct size. We tested whether nifedipine limits infarct size via NO-dependent mechanisms.

METHODS

In open chest dogs, the left anterior descending coronary artery was perfused with blood through a bypass tube and occluded for 90 min followed by 6 hours of reperfusion. Infarct size was assessed at 6 hours of reperfusion. Nifedipine of 3 or 6 microg/kg/min was infused into the bypass tube between 10 min prior to the onset of ischemia and 60 min of reperfusion.

RESULTS

Neither systemic blood pressure nor heart rate changed during infusion of nifedipine. Infarct size was reduced by the administration of nifedipine (3 or 6 microg/kg/min) compared with the untreated condition (25.6+/-2.6 and 19.1+/-3.5 vs. 43.4+/-5.6%, respectively), which was completely blunted by L-NAME (45.0+/-3.6 and 45.4+/-4.2 vs. 47.9+/-3.9% in the nifedipine (3 or 6 microg/kg/min) with L-NAME groups vs. the L-NAME group). Myeloperoxidase activity of the myocardium increased after 6 hours of reperfusion, which was attenuated by nifedipine. The limitation of infarct size and the attenuation in myeloperoxidase actiivity were completely blunted by L-NAME. There were no significant differences in collateral blood flow at 45 min of ischemia between each group.

CONCLUSIONS

We conclude that the Ca channel blocker, nifedipine, limits infarct size via NO-dependent mechanisms.

Differential subcellular actions of ACE inhibitors and AT(1) receptor antagonists on cardiac remodeling induced by chronic inhibition of NO synthesis in rats

Chronic inhibition of NO synthesis induces cardiac hypertrophy independent of systemic blood pressure (SBP) by increasing protein synthesis in vivo. We examined whether ACE inhibitors (ACEIs) enalapril and temocapril and angiotensin II type-I receptor antagonists (angiotensin receptor blockers [ARBs]) losartan and CS-866 can block cardiac hypertrophy and whether changes in activation of 70-kDa S6 kinase (p70S6K) or extracellular signal-regulated protein kinase (ERK) are involved. The following 13 groups were studied: untreated Wistar-Kyoto rats and rats treated with NO synthase inhibitor Nomega-nitro-L-arginine methyl ester (L-NAME), D-NAME (the inactive isomer of L-NAME), L-NAME plus hydralazine, L-NAME plus enalapril (3 mg. kg(-1). d(-1)) or temocapril (1 or 10 mg. kg(-1). d(-1)), L-NAME plus losartan (10 mg. kg(-1). d(-1)) or CS-866 (1 or 10 mg. kg(-1). d(-1)), L-NAME plus temocapril-CS866 in combination (1 or 10 mg. kg(-1). d(-1)), and L-NAME plus rapamycin (0.5 mg. kg(-1). d(-1)). After 8 weeks of each experiment, ratios of coronary wall to lumen (wall/lumen) and left ventricular weight to body weight (LVW/BW) were quantified. L-NAME increased SBP, wall/lumen, and LVW/BW compared with that of control. ACEIs, ARBs, and hydralazine equally canceled the increase in SBP induced by L-NAME. However, ACEIs and ARBs equally (but not hydralazine) attenuated increase in wall/lumen and LVW/BW induced by L-NAME. The L-NAME group showed both p70S6K and ERK activation in myocardium (2.2-fold and 1.8-fold versus control, respectively). ACEIs inactivated p70S6K and ARBs inactivated ERK in myocardium, but hydralazine did not change activation of either kinase. Thus, ACEIs and ARBs modulate different intracellular signaling pathways, inhibiting p70S6K or ERK, respectively, to elicit equal reduction of cardiac hypertrophy induced by chronic inhibition of NO synthesis in vivo.

Mechanisms of telomerase induction during vascular smooth muscle cell proliferation

Telomeres are primarily controlled by a highly specialized DNA polymerase termed telomerase. Recent studies have demonstrated that introduction of the telomerase catalytic component (TERT) into telomerase-negative cells activates telomerase and extends cell life span, whereas mice lacking telomerase activity revealed impaired cell proliferation in some organs as well as reduced tumorigenesis. These reports suggest that telomerase plays an important role in long-term cell viability and cell proliferation. However, the mechanism or mechanisms by which telomerase is induced or regulated remains to be elucidated. We report here that primary vascular smooth muscle cells (VSMCs) express telomerase and that increased telomerase activity correlates with cell proliferation. Inhibition of telomerase diminished growth of VSMCs, which suggests a crucial role for telomerase activation in the regulation of VSMC proliferation. We propose a novel model whereby telomerase is first activated in the cytoplasm before cell proliferation, followed by accumulation of activity in the nucleus during the logarithmic phase of cell growth. Activation of telomerase in VSMCs was linked to phosphorylation of TERT. The protein kinase inhibitor H7 suppressed the activation of telomerase in the cytoplasm and also inhibited the accumulation of TERT as well as telomerase activity in the nucleus. These data suggest that posttranslational modification of TERT by phosphorylation is important for activation and accumulation of telomerase into the nucleus in the process of VSMC proliferation.

Targeted expression of heme oxygenase-1 prevents the pulmonary inflammatory and vascular responses to hypoxia

Chronic hypoxia causes pulmonary hypertension with smooth muscle cell proliferation and matrix deposition in the wall of the pulmonary arterioles. We demonstrate here that hypoxia also induces a pronounced inflammation in the lung before the structural changes of the vessel wall. The proinflammatory action of hypoxia is mediated by the induction of distinct cytokines and chemokines and is independent of tumor necrosis factor-alpha signaling. We have previously proposed a crucial role for heme oxygenase-1 (HO-1) in protecting cardiomyocytes from hypoxic stress, and potent anti-inflammatory properties of HO-1 have been reported in models of tissue injury. We thus established transgenic mice that constitutively express HO-1 in the lung and exposed them to chronic hypoxia. HO-1 transgenic mice were protected from the development of both pulmonary inflammation as well as hypertension and vessel wall hypertrophy induced by hypoxia. Significantly, the hypoxic induction of proinflammatory cytokines and chemokines was suppressed in HO-1 transgenic mice. Our findings suggest an important protective function of enzymatic products of HO-1 activity as inhibitors of hypoxia-induced vasoconstrictive and proinflammatory pathways.

Hypoxia extends the life span of vascular smooth muscle cells through telomerase activation

Chronic hypoxia induces smooth muscle cell proliferation and vessel wall remodeling in the vasculature of the lung. One well-characterized component of the hypoxic response is transcriptional activation of genes encoding vascular smooth muscle cell (VSMC) mitogens. We report here that chronic hypoxia can also prolong the growth of human VSMC by inducing telomerase activity and telomere stabilization. We demonstrate that hypoxia induced phosphorylation of the telomerase catalytic component (TERT) and sustained high levels of TERT protein expression in VSMC compared to normoxia. Furthermore, inhibition of telomerase shortened cell life span in hypoxic cultures, whereas constitutive expression of TERT extended the life span of cells under normoxic conditions. Our data indicate that hypoxic induction of telomerase activity could be involved in long-term growth of VSMC and may thus contribute to human vascular disorders.

Inducible gene targeting in postnatal myocardium by cardiac-specific expression of a hormone-activated Cre fusion protein

Cardiac-restricted expression of Cre recombinase can provoke lineage-specific gene excision in the myocardium. However, confounding early lethality may still preclude using loss-of-function models to study the postnatal heart. Here, we have tested whether inducible, heart-specific recombination can be triggered after birth by transgenic expression of a Cre fusion protein that incorporates a mutated progesterone receptor ligand binding domain (PR1) that is activated by the synthetic antiprogestin, RU486, but not by endogenous steroid hormones. CrePR1 driven by the alpha-myosin heavy chain (alphaMHC) promoter was expressed specifically in heart. Translocation of CrePR1 from cytoplasm to nuclei in ventricular myocytes was induced by RU486. To establish whether this approach can mediate cardiac-specific, drug-dependent excision between loxP sites in vivo, we mated alphaMHC-CrePR1 mice with a ubiquitously expressed (ROSA26) Cre reporter line. Offspring harboring alphaMHC-CrePR1 and/or the floxed allele were injected with RU486 versus vehicle, and the prevalence of beta-galactosidase (beta-gal)-positive cells was determined, indicative of Cre-mediated excision. Little or no baseline recombination was seen 1 week after birth. Cardiac-restricted, RU486-inducible recombination was demonstrated in bigenic mice at age 3 and 6 weeks, using each of 3 independent CrePR1 lines. Recombination in the absence of ligand paralleled the levels of CrePR1 protein expression and was more evident at 6 weeks. Thus, conditional, posttranslational activation of a Cre fusion protein can bypass potential embryonic and perinatal effects on the heart and permits inducible recombination in cardiac muscle. High levels of the chimeric Cre protein, in particular, were associated with progressive recombination in the absence of drug.

Intergenic suppression between the flagellar MS ring protein FliF of Salmonella and FlhA, a membrane component of its export apparatus

The MS ring of the flagellar basal body of Salmonella is an integral membrane structure consisting of about 26 subunits of a 61-kDa protein, FliF. Out of many nonflagellate fliF mutants tested, three gave rise to intergenic suppressors in flagellar region II. The pseudorevertants swarmed, though poorly; this partial recovery of motile function was shown to be due to partial recovery of export function and flagellar assembly. The three parental mutants were all found to carry the same mutation, a six-base deletion corresponding to loss of Ala-174 and Ser-175 in the predicted periplasmic domain of the FliF protein. The 19 intergenic suppressors identified all lay in flhA, and they consisted of 10 independent examples at the nucleotide level or 9 at the amino acid level. Since two of the nine corresponded to different substitutions at the same amino acid position, only eight positions in the FlhA protein have given rise to suppressors. Thus, FliF-FlhA intergenic suppression is a fairly rare event. FlhA is a component of the flagellar protein export apparatus, with an integral membrane domain encompassing the N-terminal half of the sequence and a cytoplasmic C-terminal domain. All of the suppressing mutations lay within the integral membrane domain. These mutations, when placed in a wild-type fliF background, had no mutant phenotype. In the fliF mutant background, mutant FlhA was dominant, yielding a pseudorevertant phenotype. Wild-type FlhA did not exert significant negative dominance in the pseudorevertant background, indicating that it does not compete effectively with mutant FlhA for interaction with mutant FliF. Mutant FliF was partially dominant over wild-type FliF in both the wild-type and second-site FlhA backgrounds. Membrane fractionation experiments indicated that the fliF mutation, though preventing export, was mild enough to permit assembly of the MS ring itself, and also assembly of the cytoplasmic C ring onto the MS ring. The data from this study provide genetic support for a model in which at least the FlhA component of the export apparatus physically interacts with the MS ring within which it is housed.

Inhibition of nitric oxide synthesis induces coronary vascular remodeling and cardiac hypertrophy associated with the activation of p70 S6 kinase in rats

Chronic inhibition of nitric oxide (NO) synthesis is reported to induce the thickening of coronary artery walls and cardiac hypertrophy in vivo via angiotensin II receptors. Increased protein synthesis is the main feature of these structural changes. Activation of 70 kD S6 kinase (p70S6K) phosphorylates the 40S ribosomal protein S6 that regulates protein synthesis. We examined the role of p70S6K in the vascular and myocardial structural changes induced by the chronic inhibition of NO synthesis. The following 5 groups were studied: untreated Wister-Kyoto rats, those treated with an inhibitor of NO synthase, Nomega-nitro-L-arginine methyl ester (L-NAME), those treated with L-NAME and an angiotensin I converting enzyme inhibitor (imidapril), those treated with L-NAME and hydralazine, and those treated with L-NAME and an inhibitor of p70S6K (rapamycin). After 8 weeks, wall-to-lumen ratio in myocardium and cardiomyocyte cross-sectional areas were quantified. L-NAME increased systolic blood pressure, wall-to-lumen ratio, and cardiomyocyte cross-sectional area compared with control animals. Imidapril or rapamycin, but not hydralazine, markedly reduced these structural changes. L-NAME increased p70S6K activity in myocardium compared with control rats. Imidapril or rapamycin prevented the activation of p70S6K activity in myocardium induced by L-NAME. These results suggest that activation of p70S6K plays an important role in coronary vascular remodeling and cardiac hypertrophy induced by the chronic inhibition of nitric oxide synthesis in vivo.