Endothelial dysfunction associated with left ventricular diastolic dysfunction in patients with coronary heart disease

Knockout of TIGAR enhances myocardial phosphofructokinase activity and preserves diastolic function in heart failure

Hypertension is an important risk factor in the pathogenesis of diastolic dysfunction. Growing evidence indicates that glucose metabolism plays an essential role in diastolic dysfunction. TP53-induced glycolysis and apoptosis regulator (TIGAR) has been shown to regulate glucose metabolism and heart failure (HF). In the present study, we investigated the role of TIGAR in diastolic function and cardiac fibrosis during pressure overload (PO)-induced HF. WT mice subjected to transverse aortic constriction (TAC), a commonly used method to induce diastolic dysfunction, exhibited diastolic dysfunction as evidenced by increased E/A ratio and E/E' ratio when compared to its sham controls. This was accompanied by increased cardiac interstitial fibrosis. In contrast, the knockout of TIGAR attenuated PO-induced diastolic dysfunction and interstitial fibrosis. Mechanistically, the levels of glucose transporter Glut-1, Glut-4, and key glycolytic enzyme phosphofructokinase 1 (PFK-1) were significantly elevated in TIGAR KO subjected to TAC as compared to that of WT mice. Knockout of TIGAR significantly increased fructose 2,6-bisphosphate levels and phosphofructokinase activity in mouse hearts. In addition, PO resulted in a significant increase in perivascular fibrosis and endothelial activation in the WT mice, but not in the TIGAR KO mice. Our present study suggests a necessary role of TIGAR-mediated glucose metabolism in PO-induced cardiac fibrosis and diastolic dysfunction.

Impact of plasma xanthine oxidoreductase activity in patients with heart failure with preserved ejection fraction

AIMS

Reactive oxygen species are reportedly involved in the mechanism underlying heart failure with preserved ejection fraction (HFpEF); however, the disease pathophysiology remains poorly understood. Xanthine oxidoreductase (XOR), the rate-limiting enzyme of purine metabolism, plays an important role in uric acid production and generates reactive oxygen species. However, the impact of plasma XOR activity on the clinical outcomes of patients with HFpEF remains unclear. The aim of this study was to investigate whether plasma XOR activity is associated with major adverse cardiovascular events (MACEs) in patients with HFpEF.

METHODS AND RESULTS

The plasma XOR activity was measured in 257 patients with HFpEF, who were then divided into three groups according to the activity levels: low XOR group (<33 pmol/h/mL, n = 45), normal XOR group (33-120 pmol/h/mL, n = 160), and high XOR group (>120 pmol/h/mL, n = 52). During the median follow-up period of 809 days, there were 74 MACEs. Kaplan-Meier analysis revealed that the high XOR group was at the highest risk for MACEs. Multivariate analysis by Cox's proportional hazard regression approach showed that high XOR activity was significantly associated with MACEs, after adjustment for confounding factors. The patients were also divided into four groups according to the absence/presence of high XOR activity and/or hyperuricaemia. According to the multivariate Cox regression analysis, high XOR activity was associated with MACEs, regardless of the hyperuricaemia status.

CONCLUSIONS

Elevated plasma XOR activity is significantly associated with adverse clinical outcomes in patients with HFpEF.

Endothelial and left ventricular diastolic function in young adults exposed to tobacco

Smoking is associated with endothelial and left ventricular diastolic disfunction. We aimed to determine the endothelial and diastolic function in young adults exposed to tobacco smoke and the effects of acute exposure to it. Smokers were considered as cases and non-smokers as controls. Brachial artery diameter, brachial artery flow velocity, and echocardiographic variables were measured. Mean age of the participants was 21 years. Smokers showed significant endothelial dysfunction compared with non-smokers. Arterial dilation mediated by the endothelium was significantly higher in non-smokers than in smokers (p = 0.005). Non-endothelium-mediated arterial dilation was significantly impaired in smokers compared with non-smokers (p = 0.02). After reactive hyperaemia, there was a significant increase in blood flow in non-smokers (61%) compared with that in smokers (29%). Acute cigarette exposure showed a trend towards left ventricle diastolic disfunction in smokers. Left atrium diameter was significantly higher in smokers than in non-smokers. After acute exposure to cigarette smoke, arterial dilation and brachial flow velocity were lower than those achieved in the abstinence phase (p = 0.005). We concluded that endothelium-dependent arterial dilation is impaired in young smokers and it worsens even after acute exposure to cigarette smoke.

Serum endocan level and diastolic functions in the case of lead exposure

Background/aim

Lead can cause morphological and functional changes in heart, and inflammation and endothelial dysfunction in vasculature. Endocan, as a novel indicator of endothelial dysfunction, has been used for cardiovascular diseases. This study investigated the relationship between lead exposure, endocan levels, and diastolic functions.

Materials and methods

A total of 51 lead-exposed workers without a known cardiovascular disease or risk factors and 54 healthy controls were enrolled. All participants underwent transthoracic echocardiography. Blood lead and serum endocan levels were analyzed.

Results

Baseline demographic and clinical characteristics were found to be similar between groups. Median blood lead (32 vs 1.5 µg/dL, P < 0.001) and serum endocan levels (67 vs 57.1 pg/mL, P = 0.02) were significantly higher in the lead-exposed group. Serum endocan level showed a positive correlation with blood lead levels (r = 0.404, P = 0.003) in lead-exposed workers. Serum endocan level was an independent risk factor for increased E/E’ ratio (β = 0.704, P = 0.002) and left atrial volume index (β = 1.158, P = 0.011) and higher level of lead in blood was an independent risk factor for increased E wave (β = 8.004, P = 0.022) in lead-exposed workers.

Conclusion

Worsened diastolic functions may be seen in the course of lead exposure. Due to sharing a similar mechanism, a higher serum level of endocan may be a valuable laboratory clue for impaired diastolic function in this population.

Evaluation of sex differences in the relationship between diastolic dysfunction and thromboembolism using propensity score analysis

BACKGROUND

Female sex is a risk factor for thromboembolism (TE) in atrial fibrillation (AF); however, the underlying mechanisms are unclear. We postulated that left ventricular (LV) diastolic dysfunction (LVDD) could be associated with increased thromboembolic risk in women.

METHODS

From a retrospective cohort, 158 patients (female : male = 79:79) with nonvalvular AF were propensity score-matched for age, presence of diabetes, hypertension, coronary artery disease, congestive heart failure, embolic history, AF type, and AF duration. Cardiac size and function and central aortic stiffness parameters were evaluated. Diastolic function was classified as normal, indeterminate, and LVDD according to recent guidelines. Surrogate markers for thromboembolism (dense spontaneous echo contrast and thrombus) were evaluated using transesophageal echocardiography.

RESULTS

Surrogate markers for TE showed a trend to be more frequent in women than in men (21.5% vs 11.4%, P = .086). LVDD was more prevalent in women than in men (22.8% vs 2.5%, P < .001); however, the prevalence of indeterminate diastolic function was not different between sexes (26.6% vs 20.3%, P = .453). Surrogate markers for TE were detected mostly in women with LVDD. LV diastolic parameters showed a restrictive pattern, and aortic stiffness parameters were worse in women than in men. Women with LVDD had increased aortic stiffness compared to women with indeterminate and normal function, whereas aortic stiffness did not differ among men in all groups. Significant relations between LV diastolic function and aortic stiffness parameters were observed only in women.

CONCLUSION

LVDD due to increased aortic stiffness could be related to a higher thromboembolic risk in women with AF.

Correlation between Diastolic Function and Endothelial Function in Patients with Type 2 Diabetes and Hypertension

BACKGROUND

Endothelial dysfunction may be involved in the pathophysiology of cardiac abnormalities in patients with diabetes mellitus (DM). A correlation between endothelial dysfunction and diastolic dysfunction in patients with type 1 DM has been demonstrated, but this relationship has not been well investigated in type 2 DM.

OBJECTIVE

Compare groups of patients with type 2 DM and hypertension with and without diastolic dysfunction using endothelial function indexes, and to assess whether correlations exist between the diastolic function and the endothelial function indexes.

METHOD

This was a cross-sectional study of 34 men and women with type 2 DM and hypertension who were aged between 40 and 70 years and were categorized based on assessments of their Doppler echocardiographic parameters as having normal (14 patients) and abnormal (20 patients) diastolic function. Flow-mediated dilatation (FMD) assessments of the brachial artery evaluated the patients' endothelial function.

RESULTS

The mean maximum FMD was 7.15 ± 2.80% for the patients with diastolic dysfunction and it was 11.85 ± 4.77% for the patients with normal diastolic function (p = 0.004). Correlations existed between the maximum FMD and the E/e' ratio (p = 0.040, r = -0.354) and the early wave velocity (e') at the lateral mitral annulus (p = 0.002, r = 0.509).

CONCLUSION

The endothelial function assessed by FMD was worse in hypertensive diabetic patients with diastolic dysfunction. There were correlations between the diastolic function indexes and the endothelial function indexes in our sample.

Paricalcitol and endothelial function in chronic kidney disease trial

Altered vitamin D metabolism and low levels of the active form of this vitamin, 1,25-dihydroxy-vitamin D, is a hallmark of chronic kidney disease (CKD), but there is still no randomized controlled trial testing the effect of active forms of vitamin D on vascular function in patients with CKD. Paricalcitol and ENdothelial fuNction in chronic kidneY disease (PENNY) is a double-blinded randomized controlled trial (ClinicalTrials.gov, NCT01680198) testing the effect of an active form of vitamin D, paricalcitol (2 μg/d×12 weeks) on endothelium-dependent and endothelium-independent vasodilatation in 88 patients with stage 3 to 4 CKD and parathormone >65 pg/mL (paricalcitol, n=44; placebo, n=44). Paricalcitol treatment reduced parathormone (-75 pg/mL; 95% confidence interval, -90 to -60), whereas parathormone showed a small rise during placebo (21 pg/mL; 95% confidence interval, 5-36). Blood pressure did not change in both study arms. Baseline flow-mediated dilation was identical in patients on paricalcitol (3.6±2.9%) and placebo (3.6±2.9%) groups. After 12 weeks of treatment, flow-mediated dilation rose in the paricalcitol but not in the placebo group, and the between-group difference in flow-mediated dilation changes (the primary end point, 1.8%; 95% confidence interval, 0.3-3.1%) was significant (P=0.016), and the mean proportional change in flow-mediated dilation was 61% higher in paricalcitol-treated patients than in placebo-treated patients. Such an effect was abolished 2 weeks after stopping the treatment. No effect of paricalcitol on endothelium-independent vasodilatation was registered. Paricalcitol improves endothelium-dependent vasodilatation in patients with stage 3 to 4 CKD. Findings in this study support the hypothesis that vitamin D may exert favorable effects on the cardiovascular system in patients with CKD.

Endothelial function is associated with myocardial diastolic function in women with systemic lupus erythematosus

Endothelial dysfunction is associated with traditional and systemic lupus erythematosus (SLE)-specific risk factors, and early data suggest reversibility of endothelial dysfunction with therapy. The clinical relevance of endothelial function assessment has been limited by the lack of studies, demonstrating its prognostic significance and impact on early myocardial function. Therefore, we aimed to determine the association between endothelial and myocardial diastolic function in SLE women. Women with SLE and no coronary artery disease were prospectively recruited and underwent radionuclide myocardial perfusion imaging (MPI) (Jetstream, Philips, the Netherlands) to exclude subclinical myocardial ischemia. Cardiac and vascular functions were assessed in all patients (Alpha 10, Aloka, Tokyo). Diastolic function was assessed using pulse wave early (E) and late mitral blood inflow and myocardial tissue Doppler (mean of medial and lateral annulus e') velocities. Endothelial function was measured using brachial artery flow-mediated vasodilatation (FMD%). Univariate and multivariate linear regressions were used to assess the association between FMD% and myocardial diastolic function, adjusting for potential confounders. Thirty-eight patients without detectable myocardial ischemia on MPI were studied (mean age 44 ± 10 years; mean disease duration 14 ± 6 years). About 61 % of patients had normal diastolic function (E/e' ≤ 8), and 5 % of patients had definite diastolic dysfunction with E/e' > 13 (mean 7.1 ± 2.9). FMD% was associated with E/e' (regression coefficient β = -0.35; 95 % CI -0.62 to -0.08; p = 0.01) independent of systolic blood pressure, age, and SLICC/ACR Damage Index.

Association of renal biochemical parameters with left ventricular diastolic dysfunction in a community-based elderly population in China: a cross-sectional study

Background

Relationship of left ventricular diastolic dysfunction (LVDD) with parameters that could provide more information than hemodynamic renal indexes has not been clarified. We aimed to explore the association of comprehensive renal parameters with LVDD in a community-based elderly population.

Methods

1,166 community residents (aged ≥ 65 years, 694 females) participating in the Shanghai Heart Health Study with complete data of renal parameters were investigated. Echocardiography was used to evaluate diastolic function with conventional and tissue Doppler imaging techniques. Serum urea, creatinine, urea-to-creatinine ratio, estimated glomerular filtration rate (eGFR) and urinary albumin-to-creatinine ratio (UACR) were analyzed on their associations with LVDD.

Results

The prevalence of LVDD increased in proportion to increasing serum urea, urea-to-creatinine ratio and UACR. These three renal parameters were found negatively correlated to peak early (E) to late (A) diastolic velocities ratio (E/A), and positively to left atrial volume index; UACR also positively correlated with E to peak early (E’) diastolic mitral annular velocity ratio (E/E’). Serum urea, urea-to-creatinine ratio and UACR correlated with LVDD in logistic univariate regression analysis, and urea-to-creatinine ratio remained independently correlated to LVDD [Odds ratio (OR) 2.82, 95% confidence interval (CI) 1.34–5.95] after adjustment. Serum urea (OR 1.18, 95%CI 1.03–1.34), creatinine (OR 6.53, 95%CI 1.70­–25.02), eGFR (OR 0.22, 95%CI 0.07–0.65) and UACR (OR 2.15, 95%CI 1.42–3.24) were revealed independent correlates of advanced (moderate and severe) LVDD.

Conclusions

Biochemical parameters of renal function were closely linked with LVDD. This finding described new cardio-renal relationship in the elderly population.

Endothelial dysfunction over the course of coronary artery disease

The vascular endothelium regulates blood flow in response to physiological needs. Endothelial dysfunction is closely related to atherosclerosis and its risk factors, and it constitutes an intermediate step on the progression to adverse events throughout the natural history of coronary artery disease (CAD), often affecting clinical outcomes. Understanding the relation of endothelial function with CAD provides an important pathophysiological insight, which can be useful both in clinical and research management. In this review, we summarize the current knowledge on endothelial dysfunction and its prognostic influence throughout the natural history of CAD, from early atherosclerosis to post-transplant management.

Relationship between endothelial functions and acetylsalicylic acid resistance in newly diagnosed hypertensive patients

BACKGROUND

We aimed to investigate the effects and dose dependency of aspirin on endothelial functions and prevalence of aspirin resistance in newly diagnosed hypertensive patients without previous drug therapy and development of cardiac complications.

HYPOTHESIS

Acetylsalicyclic acid improves endothelial function.

METHODS

Fifty-eight hypertensive patients and 61 healthy subjects in the control group were included in the study. Endothelial functions of the patient and control groups were evaluated with brachial artery examination. Patient and control groups were divided into 2 groups. A total of 100 mg and 300 mg of aspirin were given to the separate groups for 1 week. After 1 week, endothelial functions were reevaluated and aspirin resistance examined with a platelet function analyzer (PFA-100; Dade Behring, Marbourg, Germany).

RESULTS

Baseline flow-mediated dilatation (FMD) change percent in hypertensive patients was 9.8%, and it was significantly lower than in the control group (12%) (P < 0.001). Frequency of acetylsalicylic acid (ASA) resistance was 20% and 26% in control and hypertensive patient groups, respectively (P = not significant). ASA resistance was 28% and 24% in 100 mg and 300 mg in hypertensive patients, respectively (P = not significant). FMD change percent increased both in the control and hypertensive groups after ASA treatment from 12.4% to 13.3% and 9.8 % to 11.9 %, respectively. FMD percentage change was significantly increased in hypertensive patients irrespective of ASA resistance (P = 0.02, for ASA resistance [+]; P < 0.012, for ASA resistance [-]).

CONCLUSIONS

Endothelial functions were impaired more in hypertensive patients compared to the control group. Endothelial functions were improved with all ASA doses in hypertensive patients irrespective of ASA resistance.

Severity of erectile dysfunction could predict left ventricular diastolic dysfunction in patients without overt cardiac complaint

INTRODUCTION

It has been repeatedly demonstrated that presence of erectile dysfunction (ED) may predate the occurrence of overt event of coronary artery disease. However, the association between severity of ED and left ventricular diastolic dysfunction (LVDD) was rarely reported.

AIM

The aim of this study was to assess the association between severity of ED and LVDD in patients without overt cardiac complaint.

MAIN OUTCOME MEASURES

The International Index of Erectile Function (IIEF) was used to assess erectile function. Diastolic Doppler parameters measurements and tissue Doppler imaging were used to assess left ventricular diastolic function.

METHODS

A total of 230 male ED patients without overt cardiac complaint were enrolled in this study. Erectile function was assessed using the IIEF. Patients were also screened for socio demographic data and medical comorbidities that included age, smoking, diabetes, hypertension, and dyslipidemia. All patients were referred to cardiologist for cardiac assessment. Left ventricular diastolic function that included diastolic Doppler parameters measurements and tissue Doppler imaging were also assessed.

RESULTS

Mean age±standard deviation was 57.5±5.6 (range of 42-81). There were significant associations between the following risk factors: age, obesity, smoking, hypertension, dyslipidemia, and increased severity of ED (P<0.05 for each). Of the patients, 77.4%, 74.8%, 80%, and 66.1% had abnormal transmitral E/A (E/A) ratio, deceleration time (DT), isovolumic relaxation time (IVRT), mitral E velocity/tissue Doppler imaging E velocity (E/Em) ratio, respectively. Only the means of IVRT and (E/Em) ratio had significant associations with increased severity of ED (P<0.001 for each). There were significant associations between increased severity of ED and the following categorical echo parameters: grades 1 and 2 of E/A ratio, DT, IVRT, and grades 1, 2, and 3 of (E/Em) ratio (P<0.05 for each).

CONCLUSIONS

The current study clearly demonstrated that LVDD is prevalent among patients with ED-associated medical comorbidities without overt cardiac complaint. There were significant associations between increased severity of ED and presence of LVDD in those patients.

Hypertension as an underlying factor in heart failure with preserved ejection fraction

The unique pathophysiology of heart failure with a preserved ejection fraction (HF-PEF) and the involvement of hypertension in its development are only poorly understood. The upregulation of the renin-angiotensin-aldosterone system (RAAS) has been identified as a key pathologic pathway contributing to fibrosis, cardiomyocyte abnormalities, inflammation, and endothelial dysfunction, all of which have been implicated in the progression of hypertension to HF-PEF. In addition, pharmacologic inhibition of the RAAS has been shown in animal models of diastolic dysfunction and in clinical trials to reduce these deleterious processes and to improve diastolic function. Despite these data, clinical trials performed with RAAS inhibitors in patients with HF-PEF have failed to demonstrate morbidity and mortality benefits. To date, there is no proven effective therapy specifically for HF-PEF. The deleterious effects of hypertension on mechanisms underlying the development of HF-PEF underscore the importance of effective and early control of hypertension for the prevention of HF-PEF.

Left ventricular diastolic function and endothelial function in patients with erectile dysfunction

The aim of this study was to assess left ventricular diastolic function and forearm endothelial function in patients with erectile dysfunction (ED) without overt cardiovascular disease. Forearm endothelial function and diastolic Doppler parameters, including tissue Doppler imaging, were studied in 32 men with ED and 27 age-matched, healthy, male control subjects. Left ventricular diastolic function in patients with ED and the relation between endothelium-dependent vasodilation and the Doppler parameters of left ventricular diastolic function, including tissue Doppler imaging, were assessed. Endothelium-dependent vasodilation (4.1+/-3.3% vs 9.7+/-4.2%, p<0.001) as well as the mitral inflow E velocity (0.66+/-0.17 vs 0.80+/-0.16 m/s, p=0.01), the E/A ratio (the ratio of mitral inflow E velocity to mitral inflow A velocity; 0.91+/-0.3% vs 1.22+/-0.26%, p<0.001), and the E/Em ratio (the ratio of mitral A-wave velocity to early diastolic velocity in the annulus derived by tissue Doppler imaging; 7.4+/-2.7% vs 6.6+/-1.6%, p=0.03) were smaller in the ED group than in the control group. Deceleration time (228.6+/-61.6 vs 192.9+/-44.6 ms, p=0.03) and isovolumetric relaxation time (112.8+/-18 vs 94+/-15.9 ms, p<0.001) were also prolonged in the ED group compared with the control group. The mitral E-wave velocity (r=0.40, p=0.022), the E/A ratio (r=0.40, p=0.027), and the E/Em ratio (r=-0.52, p= 0.003) were related to endothelium-dependent vasodilation by nivariate analysis. Only the E/Em ratio was correlated with endothelium-dependent vasodilation by multivariate analysis. In conclusion, this study indicates that endothelial function and left ventricular diastolic function are impaired in patients with ED without overt cardiovascular disease.

Close relationship between the vasodilator response to acetylcholine in the brachial and coronary artery in suspected coronary artery disease

BACKGROUND

Vasodilator response to acetylcholine (endothelium-dependent dilation) is impaired in the peripheral and coronary circulation in patients with coronary artery disease (CAD). The purpose of this study is to investigate if the vasodilator response to acetylcholine in the brachial artery (BA) correlates with the same response in the coronary artery (CA).

STUDY

We measured the flow responses of BA and CA in 57 patients with suspected CAD. Doppler guidewire was placed into the proximal portion of the left BA and the major branch of CA. Acetylcholine was infused at 7.5, 15, and 30 mug/min for 5 min into BA and at 10(-8), 10(-7), 10(-6) M for 3 min into CA, respectively. The flow was calculated by multiplying average peak velocity by cross sectional areas obtained from quantitative angiography. Vasodilator response to acetylcholine was assessed by ratio of acetylcholine-induced flow/baseline flow.

RESULTS

A total of 33 CAD patients (CAD group, 61+/-8 years old) and 24 normal coronary patients (NL group, 57+/-12 years old) were investigated. A strong correlation between the vasodilator response to acetylcholine in BA and CA was observed in both CAD and NL groups, only at two moderate doses of acetylcholine (CAD group, r=0.64, p<0.001, NL group, r=0.87, p<0.001, 15 microg/min vs. 10(-7) M; CAD group, r=0.68, p<0.001, NL group, r=0.72, p<0.001, 30 microg/min vs. 10(-6) M). No significant correlation was obtained during low dose acetylcholine infusion.

CONCLUSIONS

The brachial artery vasodilator response to optimal acetylcholine doses is a useful surrogate for coronary endothelial function studies.

Apolipoprotein E phenotype affects the malondialdehyde-modified LDL concentration and forearm endothelial function in postmenopausal women

OBJECTIVE

We investigated whether the apolipoprotein E (apo E) phenotype affects the serum concentration of malondialdehyde-modified low-density lipoprotein (MDA-LDL) or forearm endothelial function in postmenopausal women.

PATIENTS AND MEASUREMENTS

Individuals were divided into three groups according to their apo E phenotype: E2 (E2/2 and E2/3, n = 12); E3 (E3/3, n = 71); and E4 (E3/4 and E4/4, n = 27). The serum concentrations of lipids and MDA-LDL were measured. Forearm blood flow during reactive hyperaemia and after sublingual nitroglycerin administration was measured by strain-gauge plethysmography.

RESULTS

The serum concentrations of total and LDL cholesterol were significantly higher in the E4 group than in the E2 group (P < 0.05) or in the E3 group (P < 0.05). The serum apo B concentration was significantly higher in the E4 group than in the E2 group (P < 0.05). The serum concentrations of high density lipoprotein (HDL) cholesterol and nitrite/nitrate were significantly lower in the E4 group than in the E2 group (P < 0.05). Other lipid concentrations did not differ in the three groups. The serum MDA-LDL concentration was highest in the E4 group, and was lowest in the E2 group (E2: 91.1 +/- 6.9 IU/l, E3: 112.3 +/- 5.9 IU/l, E4: 128.8 +/- 9.9 IU/l; P < 0.05). The forearm blood flow response to reactive hyperaemia was lowest in the E4 group, and highest in the E2 group (E2: 52.2 +/- 5.8 ml/min per 100 ml tissue, E3: 40.7 +/- 1.7 ml/min per 100 ml tissue, E4: 33.4 +/- 2.4 ml/min per 100 ml tissue; P < 0.05). The forearm blood flow changes in response to nitroglycerine were similar between all three groups.

CONCLUSIONS

The apo E phenotype affects the serum MDA-LDL concentration and forearm endothelial function in postmenopausal women.