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1.
J Cardiovasc Imaging ; 32(1): 6, 2024 Jun 12.
Article in English | MEDLINE | ID: mdl-38907294

ABSTRACT

BACKGROUND: Patients with end-stage renal disease (ESRD) who are on hemodialysis (HD) have reduced vascular compliance and are likely to develop heart failure (HF). In this study, we estimated the prevalence of HF pre- and post-HD in ESRD using the current guidelines. METHODS: We prospectively investigated HF in ESRD patients on HD using echocardiography pre- and post-HD. We used the structural and functional abnormality criteria of the 2021 European Society of Cardiology guidelines. RESULTS: A total of 54 patients were enrolled. The mean age was 62.6 years, and 40.1% were male. Forty-five patients (83.3%) had hypertension, 28 (51.9%) had diabetes, and 20 (37.0%) had ischemic heart disease. The mean N-terminal-pro brain natriuretic peptide BNP (NT-proBNP) level was 12,388.8 ± 2,592.2 pg/dL. The mean ideal body weight was 59.3 kg, mean hemodialysis time was 237.4 min, and mean real filtration was 2.8 kg. The mean left ventricular ejection fraction (LVEF) was 62.4%, and mean left ventricular end-diastolic diameter was 52.0 mm in pre-HD. Post-HD echocardiography showed significantly lower left atrial volume index (33.3 ± 15.9 vs. 40.6 ± 17.1, p = 0.030), tricuspid regurgitation jet V (2.5 ± 0.4 vs. 2.8 ± 0.4 m/s, p < 0.001), and right ventricular systolic pressure (32.1 ± 10.3 vs. 38.4 ± 11.6, p = 0.005) compared with pre-HD. There were no differences in LVEF, E/E' ratio, or left ventricular global longitudinal strain. A total of 88.9% of pre-HD patients and 66.7% of post-HD patients had either structural or functional abnormalities in echocardiographic parameters according to recent HF guidelines (p = 0.007). CONCLUSIONS: Our data showed that the majority of patients undergoing hemodialysis satisfy the diagnostic criteria for HF according to current HF guidelines. Pre-HD patients had a 22.2% higher incidence in the prevalence of functional or structural abnormalities as compared with post-HD patients.

3.
J Clin Hypertens (Greenwich) ; 25(5): 429-439, 2023 05.
Article in English | MEDLINE | ID: mdl-37095689

ABSTRACT

We compared the efficacy and safety of third-standard-dose triple and third-standard-dose dual antihypertensive combination therapies in patients with mild to moderate hypertension. This was a phase II multicenter, randomized, double-blind, parallel-group trial. After a 4-week placebo run-in period, 245 participants were randomized to the third-dose triple combination (ALC group; amlodipine 1.67 mg + losartan potassium 16.67 mg + chlorthalidone 4.17 mg) or third-dose dual combination (AL group; amlodipine 1.67 mg + losartan potassium 16.67 mg, LC group; losartan potassium 16.67 mg + chlorthalidone 4.17 mg, AC group; amlodipine 1.67 mg + chlorthalidone 4.17 mg) therapy groups and followed up for 8 weeks. The mean systolic blood pressure (BP) reduction was -18.3 ± 13.2, -13.0 ± 13.3, -16.3 ± 12.4, and -13.8 ± 13.2 mmHg in the ALC, AL, LC, and AC groups, respectively. The ALC group showed significant systolic BP reduction compared to the AL and AC groups at weeks 4 (P = .010 and P = .018, respectively) and 8 (P = .017 and P = .036, respectively). At week 4, the proportion of systolic BP responders was significantly higher in the ALC group (42.6%) than in the AL (22.0%), LC (23.3%), and AC (27.1%) groups (P = .013, P = .021, and P = .045, respectively). At week 8, the proportion of systolic and diastolic BP responders was significantly higher in the ALC group (59.7%) than in the AL (39.3%) and AC (42.4%) groups (P = .022 and P = .049, respectively) at week 8. Third-standard-dose triple antihypertensive combination therapy demonstrated early effective BP control compared to third-standard-dose dual combination therapies, without increasing adverse drug reactions in patients with mild-to-moderate hypertension.


Subject(s)
Hypertension , Hypotension , Humans , Antihypertensive Agents/adverse effects , Losartan , Chlorthalidone , Amlodipine , Blood Pressure , Hypotension/chemically induced , Double-Blind Method , Drug Therapy, Combination , Treatment Outcome
4.
Int J Heart Fail ; 4(4): 183-192, 2022 Oct.
Article in English | MEDLINE | ID: mdl-36381017

ABSTRACT

Background and Objectives: Inhibitors of sodium-glucose cotransporter 2 (SGLT2i) reduce the risk of hospitalization for heart failure (HF). We aimed to examine the effect of empagliflozin on change of diuretics dose in outpatient HF patients. Methods: We retrospectively reviewed the medical records of 612 patients who were treated using both empagliflozin and diuretics. We excluded patients who did not meet the criteria for HF. Dose and duration of empagliflozin and diuretics were measured. Results: Of 612 patients, a total of 251 was analyzed and followed for a mean 430.0±175.4 days. The mean age was 69.3, 51.8% were female, and 93.2% had type 2 diabetes. The distribution of initial diuretics type when starting empagliflozin showed that furosemide comprised 24.7%, spironolactone 20.7%, thiazide 36.9%, and others. Total 23.1% of patients reduced diuretic dose, 13.1% increased diuretic dose, 41.4% continued at the same diuretic dose, and 22.3% switched to different diuretics. Among patients who were using furosemide, 36.0% reduced diuretics dose. There was a diuretic reduction in 22.6% of HF preserved ejection fraction (HFpEF, left ventricular ejection fraction [LVEF] ≥50%) and in 26.5% of HF reduced EF (HFrEF, LVEF <50%). The average doses furosemide at the start of empagliflozin decreased from 16.3mg/day to 8.5mg/day at the time of follow-up. Conclusions: Among outpatient clinic HF patients treated with both diuretics and empagliflozin, 23.1% of patients had their diuretics reduced, and the mean dose of furosemide was reduced by about half. This suggests that empagliflozin has clinical advantages in managing outpatient HF patients.

5.
Int J Heart Fail ; 4(3): 154-162, 2022 Jul.
Article in English | MEDLINE | ID: mdl-36262795

ABSTRACT

Background and Objectives: Many patients with end-stage renal disease (ESRD) on hemodialysis (HD) have reduced vascular compliance and are likely to develop heart failure (HF). This study aimed to determine the factors associated with acute decompensation events among ESRD patients undergoing HD. Methods: We retrospectively investigated ESRD patients on HD using a medical record review. We divided the patients into those admitted to hospital due to acute decompensated heart failure (ADHF) and those who were not. We compared the medical histories, electrocardiograms, and echocardiographic and laboratory data between the two groups. Results: Of the 188 ESRD patients on HD, 87 were excluded, and 101 were enrolled (mean age: 63.7 years; 52.1% male). Thirty patients (29.7%) were admitted due to ADHF. These patients exhibited similar left ventricular ejection fraction (LVEF), left ventricular (LV) mass index, and E/E' values compared to the non-ADHF group. However, the ADHF group exhibited significantly higher tricuspid regurgitation (TR) jet velocity (2.9±0.6 vs. 2.5±0.4 m/s; p=0.004) and right ventricular systolic pressure (RVSP) (43.5±17.2 vs. 34.2±9.9 mmHg; p=0.009) than the non-ADHF group, respectively. A multivariate logistic regression analysis demonstrated that the TR jet velocity (odds ratio, 8.356; 95% confidence interval, 1.806-38.658; p=0.007) was an independent predictor of ADHF after adjusting for age and sex, while the LVEF and E/E' were not. Conclusions: Our data showed that an increased TR jet velocity was an independent predictor of ADHF events in ESRD patients on HD, but the LVEF and E/E' were not.

6.
Int J Heart Fail ; 3(1): 59-68, 2021 Jan.
Article in English | MEDLINE | ID: mdl-36263109

ABSTRACT

Background and Objectives: Endurance exercise training (ET) can improve outcomes for patients with heart failure (HF). We investigated the preventive effects of ET on serum biomarkers for HF in mice treated with doxorubicin (DOX). Methods: A cohort of male wild-type mice were randomly assigned to 3 groups: sedentary control (CON), DOX-treated sedentary (DOX), and DOX-treated endurance ET (ET-DOX) groups. ET groups performed moderate intensity endurance ET on a motor treadmill for 8 weeks. After 8 weeks, the DOX and ET-DOX groups were treated with DOX via weekly intraperitoneal injections of 8 mg/kg for a total of 4 weeks. We compared M-mode echocardiography, histology, and biomarkers for HF between groups. Results: A total of 30 mice survived during the study period and were analyzed: CON (n=9), DOX (n=9) and ET-DOX (n=12). There was no significant difference in left ventricular ejection fraction (LVEF) or fractional shortening (FS) between DOX and ET-DOX groups. The ET-DOX group had a significantly lower soluble ST2 level (176.6±44.1 vs. 225.4±60.5 pg/mL, p=0.021) compared to the DOX group. Also similar between the ET-DOX and the DOX groups were the serum N-terminal prohormone of brain natriuretic peptide (30.3±12.5 vs. 34.0±21.7 pg/mL, p=0.849), troponin I (685.7±99.2 vs. 722.5±126.7 pg/mL, p=0.766), and neutrophil gelatinase-associated lipocalin (324.3±82.4 vs. 312.7±68.2 pg/mL, p=0.922) levels. Histologically, there was no significant difference in degree of perivascular fibrosis between DOX and ET-DOX groups. Conclusions: Endurance ET is effective for preventing increases in serum soluble ST2 in mice treated with DOX.

7.
Clin Hypertens ; 23: 24, 2017.
Article in English | MEDLINE | ID: mdl-29238609

ABSTRACT

BACKGROUND: Autonomic nervous system activity has been shown to be altered in patients with vasospastic angina (VA). Heart rate recovery (HRR) is a simple, non-invasive measurement of autonomic nervous system dysfunction. We aimed to investigate whether HRR is related to VA, as established by an ergonovine test. METHODS: A total of 976 consecutive patients (47.5% male, mean age 55 years) without significant coronary artery disease who underwent both an ergonovine provocation test and a treadmill exercise test were enrolled. The relationship between VA and HRR was evaluated. RESULTS: A total of 30.7% (300/976) of patients were diagnosed with VA, as documented by the ergonovine provocation test. HRR was significantly reduced in patients with VA compared to patients without VA (24.6 ± 18.0 vs. 30.5 ± 22.2, p < 0.001), and HRR was lowest in patients with multi-vessel spasm (21.9 ± 17.3). The proportion of blunted HRR, which was defined as HRR less than 12 beats, was significantly higher in patients with VA than in those without coronary artery spasm (26.6% vs. 39.3%, p < 0.001). In multivariable regression analyses, age (odds ratio (OR) = 1.03; 95% confidence interval (CI): 1.01-1.04; p = 0.001), blunted HRR (OR = 1.71; 95% CI: 1.26-2.31; p < 0.001), current smoking status (OR = 2.11; 95% CI: 1.50-2.98; p < 0.001), and male gender (OR = 2.00; 95% CI: 1.43-2.78; p < 0.001) were significant independent predictors of VA presence. CONCLUSION: Blunted HRR was an independent predictor of VA presence, which suggests a link between coronary artery spasm and autonomic dysregulation.

8.
J Cardiovasc Ultrasound ; 24(2): 115-22, 2016 Jun.
Article in English | MEDLINE | ID: mdl-27358703

ABSTRACT

BACKGROUND: Neutrophil-to-lymphocyte ratio (NLR) has recently emerged as a new important inflammatory marker for predicting cardiovascular events. This study aimed to evaluate the combined impact of NLR and type 2 diabetes mellitus (T2DM) on significant coronary artery disease (CAD) and carotid artery atherosclerosis. METHODS: This study includes a total of 828 patients evaluated by coronary angiography and carotid ultrasonography. Significant CAD was defined as at least one vessel with stenosis greater than 50%. We employed logistic regression models to investigate the association of NLR and T2DM with significant CAD. The goodness-of-fit and discriminability of the models were assessed by the loglikelihood ratio test and C-index, respectively. Also, we investigated the clinical relevance of the categorized NLR that classifies patients into three risk groups (low, intermediate, high). RESULTS: According to logistic regression analysis, both NLR {adjusted odds ratio (OR) 1.31, p < 0.001} and T2DM (adjusted OR 2.46, p = 0.006) were independent risk factors of significant CAD. The addition of NLR and T2DM into a logistic regression model including conventional cardiovascular risk factors significantly improved the goodness-of-fit (p < 0.001) and the discriminability of the model (p = 0.004). Also, T2DM patients assigned into the high risk group (NLR > 2) showed the greater prevalence of significant CAD and carotid artery atherosclerosis compared with patients without T2DM or type 2 diabetic patients assigned into the low risk group (NLR ≤ 1). CONCLUSION: Our results suggest that type 2 diabetic patients with high inflammatory state would be more vulnerable to significant CAD and carotid artery atherosclerosis.

9.
J Cardiol ; 68(2): 110-6, 2016 08.
Article in English | MEDLINE | ID: mdl-26775889

ABSTRACT

BACKGROUND: We aimed to investigate the role of brain natriuretic peptide (BNP) levels and left ventricular (LV) filling pressures in thromboembolic risk in patients with non-valvular atrial fibrillation (AF). METHODS: Among 327 patients with non-valvular AF, the ratio of peak early filling velocity to mitral annulus velocity (E/Ea) and N-terminal proBNP (NT-proBNP) was compared according to the presence of left atrial appendage (LAA) dysfunction [presence of spontaneous echo contrast (SEC)≥grade 3 and/or reduced LAA emptying flow velocity <20cm/s]. RESULTS: Compared to patients without LAA dysfunction, patients with LAA dysfunction presented with significantly higher CHADS2 scores (1.24±1.14 vs. 1.68±1.31, p=0.005), high-sensitivity C-reactive protein (0.36±1.18mg/dl vs. 0.66±1.32mg/dl, p=0.043), and NT-proBNP (765.3±2534.8pg/ml vs. 2266.9±6117.4pg/ml, p=0.002). Furthermore, patients with LAA dysfunction showed significantly higher left atrial volume index (LAVI, 25.1±10.9 vs. 43.1±22.1, p<0.001) and E/Ea (10.8±7.27 vs. 7.97±2.50mg/dl, p<0.001). Plasma logNT-proBNP levels were significantly correlated with the presence of SEC (r=0.276, p<0.001), LAA emptying flow velocity (r=-0.492, p<0.001), LAVI (r=0.405, p<0.001), and E/Ea (r=0.353, p<0.001). Binary logistic regression analysis showed that high NT-proBNP level >249.7pg/ml (odds ratio, OR 6.79, 95% confidence interval, CI 3.16-15.55, p<0.001) and E/Ea >10 (OR 4.41, 95% CI 2.39-8.15, p<0.001) were independent predictors of LAA dysfunction after adjustment of known thromboembolic risk factors. CONCLUSION: Elevated plasma NT-proBNP concentrations and LV filling pressures represented by LAA dysfunction may be reliable surrogate markers for predicting thromboembolic risk in patients with AF.


Subject(s)
Atrial Fibrillation/blood , Atrial Fibrillation/physiopathology , Natriuretic Peptide, Brain/blood , Peptide Fragments/blood , Thromboembolism/etiology , Aged , Atrial Appendage/physiopathology , Atrial Fibrillation/complications , Biomarkers/blood , Blood Flow Velocity , C-Reactive Protein/analysis , Female , Humans , Logistic Models , Male , Middle Aged , Mitral Valve/physiopathology , Odds Ratio , Risk Factors , Severity of Illness Index , Stroke Volume
10.
Nanomaterials (Basel) ; 6(5)2016 Apr 27.
Article in English | MEDLINE | ID: mdl-28335210

ABSTRACT

Water-dispersible ZnS:Mn nanocrystals (NCs) were synthesized by capping the surface with polar L-aspartic acid (Asp) molecules. The obtained ZnS:Mn-Asp NC product was optically and physically characterized using the corresponding spectroscopic methods. The ultra violet-visible (UV-VIS) absorption spectrum and photoluminescence (PL) emission spectrum of the NCs showed broad peaks at 320 and 590 nm, respectively. The average particle size measured from the obtained high resolution-transmission electron microscopy (HR-TEM) image was 5.25 nm, which was also in accordance with the Debye-Scherrer calculations using the X-ray diffraction (XRD) data. Moreover, the surface charge and degree of aggregation of the ZnS:Mn-Asp NCs were determined by electrophoretic and hydrodynamic light scattering methods, respectively. These results indicated the formation of agglomerates in water with an average size of 19.8 nm, and a negative surface charge (-4.58 mV) in water at ambient temperature. The negatively-charged NCs were applied as a photosensor for the detection of specific cations in aqueous solution. Accordingly, the ZnS:Mn-Asp NCs showed an exclusive luminescence quenching upon addition of copper (II) cations. The kinetic mechanism study on the luminescence quenching of the NCs by the addition of the Cu2+ ions proposed an energy transfer through the ionic binding between the two oppositely-charged ZnS:Mn-Asp NCs and Cu2+ ions.

11.
J Diabetes Res ; 2015: 924539, 2015.
Article in English | MEDLINE | ID: mdl-26064992

ABSTRACT

This study aimed to investigate the effects of gender on the association between epicardial fat thickness (EFT) and circadian blood pressure (BP) changes in patients with recently diagnosed essential hypertension (EH). A total of 441 patients with EH (male/female: 236/205, mean age: 50.7 ± 13.8) and 83 control patients underwent 24-hour ambulatory BP monitoring and echocardiography. Obese EH patients had higher circadian BP profile with BP variability, wall thickness, and left ventricular mass than nonobese EH patients and controls (all p's <0.05) without gender differences. EFT was higher in female than in male patients (7.0 ± 2.5 versus 5.9 ± 2.2 mm, p < 0.001) and higher in the obese female EH group (7.5 ± 2.6 mm) than in the control (6.4 ± 2.8 mm) or nonobese EH group (6.7 ± 2.8 mm) among women, whereas EFT did not vary among males (5.9 ± 1.9 versus 6.0 ± 2.7 versus 5.9 ± 2.4 mm, p = 0.937). Multivariate logistic regression analysis demonstrated that the 24-hour mean BP variability was associated with SBP (p = 0.018) and EFT (p = 0.016) in female patients, but not in male patients. The relationships among circadian BP variability, obesity, and EFT were affected by gender in different manners. EFT may be a more valuable parameter in the evaluation of BP severity and obesity in women than in men.


Subject(s)
Blood Pressure/physiology , Circadian Rhythm/physiology , Hypertension/physiopathology , Intra-Abdominal Fat/diagnostic imaging , Obesity/physiopathology , Adult , Cross-Sectional Studies , Echocardiography , Essential Hypertension , Female , Humans , Hypertension/complications , Hypertension/diagnostic imaging , Male , Middle Aged , Obesity/complications , Obesity/diagnostic imaging , Pericardium , Sex Factors
12.
Korean Circ J ; 45(2): 125-30, 2015 Mar.
Article in English | MEDLINE | ID: mdl-25810734

ABSTRACT

BACKGROUND AND OBJECTIVES: Subclinical hypothyroidism is associated with endothelial dysfunction and impaired coronary flow reserve. However, the effect of subclinical hypothyroidism or thyroid autoimmunity on variant angina has yet to be determined. SUBJECTS AND METHODS: Among 385 consecutive patients without associated cardiovascular risk factors who underwent coronary angiography with the ergonovine provocation test (EPT), 165 had a positive EPT {EPT(+)} and 220 had a negative EPT {EPT(-)}. The relationship between coronary artery spasm and the presence of subclinical thyroid dysfunction as well as serum thyroid peroxidase autoantibody (TPO Ab) was evaluated. RESULTS: The proportion of patients with subclinical hypothyroidism among those who were EPT(+) was significantly higher than that in those who were EPT(-) (18% vs. 11%, p=0.001). However, there was no significant difference in the proportion of patients with subclinical hyperthyroidism between the groups. Moreover, EPT(+) patients showed significantly more positive TPO Ab (33% vs. 14%, p<0.001) than those with EPT(-). There was a positive correlation between EPT(+) and TPO positivity (r=0.226, p<0.001), subclinical hypothyroidism (r=0.112, p=0.033), and body mass index (r=0.123, p=0.018). Binary logistic regression analysis revealed that the significant predictors of EPT(+) were body mass index {adjusted odds ratio (OR)=1.042, 95% confidence interval (CI)=1.005-1.080}, presence of subclinical hypothyroidism (OR=3.047, 95% CI=1.083-8.572), TPO Ab titer (OR=1.028, 95% CI=1.015-1.041), and the presence of TPO Ab (OR=4.904, 95% CI=1.544-15.567). CONCLUSION: Subclinical hypothyroidism and the presence of TPO Ab are significantly associated with coronary vasospasm in patients without cardiovascular risk factors.

13.
Nanomaterials (Basel) ; 5(4): 1955-1970, 2015 Nov 11.
Article in English | MEDLINE | ID: mdl-28347105

ABSTRACT

Water-dispersible ZnS:Mn nanocrystals (NC) were synthesized by capping the surface with mercaptoacetic acid (MAA) molecules at three different pH conditions. The obtained ZnS:Mn-MAA NC products were physically and optically characterized by corresponding spectroscopic methods. The UV-Visible absorption spectra and PL emission spectra showed broad peaks at 310 and 590 nm, respectively. The average particle sizes measured from the HR-TEM images were 5 nm, which were also supported by the Debye-Scherrer calculations using the X-ray diffraction (XRD) data. Moreover, the surface charges and the degrees of aggregation of the ZnS:Mn-MAA NCs were determined by electrophoretic and hydrodynamic light scattering methods, indicating formation of agglomerates in water with various sizes (50-440 nm) and different surface charge values accordingly the preparation conditions of the NCs (-7.59 to -24.98 mV). Finally, the relative photocatalytic activities of the ZnS:Mn-MAA NCs were evaluated by measuring the degradation rate of methylene blue (MB) molecule in a pseudo first-order reaction condition under the UV-visible light irradiation. As a result, the ZnS:Mn-MAA NC prepared at the pH 7 showed the best photo-degradation efficiency of the MB molecule with the first-order rate constant (kobs) of 2.0 × 10-3·min-1.

14.
Heart Vessels ; 30(4): 490-7, 2015 Jul.
Article in English | MEDLINE | ID: mdl-24691701

ABSTRACT

The purpose of this study was to investigate the time-dependent effect of statin treatment and echocardiographic epicardial fat thickness (EFT) on the maintenance of sinus rhythm (SR) in atrial fibrillation (AF) patients after electrical cardioversion (EC). One hundred sixty-three AF patients without previous statin treatment who underwent EC were consecutively enrolled. The maintenance rate of SR after EC (1, 3, 6, and 12 months) as documented by electrocardiogram and EFT were compared between patients with statin treatment (statin group, n = 63) and those without (no statin group, n = 100). There was no significant difference in the maintenance rate of SR between the groups soon after EC (statin group; 85.7 % vs. no statin; 84.8%, p = 0.535), after 1 month (71.0 vs. 59.1%, p = 0.091), and after 3 months (63.2 vs. 50.0%, p = 0.086). However, the maintenance rate of SR was significantly higher in the statin group compared to no statin group (61.8 vs. 42.9%, p = 0.024) after 6 months, and this significant difference persisted up to 12 months of follow up (60.1 vs. 36.4%, p = 0.001). Patients with recurrence showed higher baseline EFT (7.4 ± 2.7 vs. 8.5 ± 3.0 mm, p = 0.014). Multivariate linear regression analysis indicated that EFT, left atrial diameter, high-density lipoprotein cholesterol, statin treatment, and dose were the significant contributors to the maintenance of SR for all periods after EC. Statin treatment and low EFT were associated with a higher maintenance rate of SR in AF patients after EC. Significant benefit of statin was realized 6 months after EC, and this benefit was shown to be maintained over time.


Subject(s)
Atrial Fibrillation/drug therapy , Electric Countershock/instrumentation , Heart Atria/diagnostic imaging , Hydroxymethylglutaryl-CoA Reductase Inhibitors/administration & dosage , Pericardium/diagnostic imaging , Aged , Echocardiography , Electrocardiography , Female , Humans , Linear Models , Male , Middle Aged , Multivariate Analysis , Prognosis , Prospective Studies , Recurrence
15.
PLoS One ; 9(10): e106570, 2014.
Article in English | MEDLINE | ID: mdl-25329899

ABSTRACT

Statins, 3-hydroxy-3-methyl-glutaryl-CoA reductase inhibitors, are associated with the prevention of atrial fibrillation (AF) by pleiotropic effects. Recent clinical trial studies have demonstrated conflicting results on anti-arrhythmia between lipophilic and hydrophilic statins. However, the underlying mechanisms responsible for anti-arrhythmogenic effects of statins are largely unexplored. In this study, we evaluated the different roles of lipophilic and hydrophilic statins (simvastatin and pravastatin, respectively) in acetylcholine (100 µM)-activated K+ current (IKACh, recorded by nystatin-perforated whole cell patch clamp technique) which are important for AF initiation and maintenance in mouse atrial cardiomyocytes. Our results showed that simvastatin (1-10 µM) inhibited both peak and quasi-steady-state IKACh in a dose-dependent manner. In contrast, pravastatin (10 µM) had no effect on IKACh. Supplementation of substrates for the synthesis of cholesterol (mevalonate, geranylgeranyl pyrophosphate or farnesyl pyrophosphate) did not reverse the effect of simvastatin on IKACh, suggesting a cholesterol-independent effect on IKACh. Furthermore, supplementation of phosphatidylinositol 4,5-bisphosphate, extracellular perfusion of phospholipase C inhibitor or a protein kinase C (PKC) inhibitor had no effect on the inhibitory activity of simvastatin on IKACh. Simvastatin also inhibits adenosine activated IKACh, however, simvastatin does not inhibit IKACh after activated by intracellular loading of GTP gamma S. Importantly, shortening of the action potential duration by acetylcholine was restored by simvastatin but not by pravastatin. Together, these findings demonstrate that lipophilic statins but not hydrophilic statins attenuate IKACh in atrial cardiomyocytes via a mechanism that is independent of cholesterol synthesis or PKC pathway, but may be via the blockade of acetylcholine binding site. Our results may provide important background information for the use of statins in patients with AF.


Subject(s)
Acetylcholine/pharmacology , Atrial Fibrillation/prevention & control , Electrophysiological Phenomena/drug effects , Heart Atria/cytology , Hydroxymethylglutaryl-CoA Reductase Inhibitors/pharmacology , Myocytes, Cardiac/drug effects , Potassium/metabolism , Action Potentials/drug effects , Animals , Heart Atria/physiopathology , Hydrophobic and Hydrophilic Interactions , Mice , Myocytes, Cardiac/cytology , Pravastatin/chemistry , Pravastatin/pharmacology , Simvastatin/chemistry , Simvastatin/pharmacology
16.
Int J Mol Sci ; 15(8): 14803-18, 2014 Aug 22.
Article in English | MEDLINE | ID: mdl-25153633

ABSTRACT

Increased atrial oxidative stress has an important role in inducing and maintaining atrial fibrillation (AF), and the activation of the small GTPase Rac1 contributes to the oxidative stress. We investigated the relationship of Rac1, atrial endothelial thromboprotective markers and AF inducibility and if simvastatin has a potential beneficial effect on a myocardial infarction (MI)-induced heart failure (HF) rat model. Rats were randomized into three groups (shams, MI group and simvastatin treatment group) and underwent echocardiography, AF induction studies and left atrial (LA) fibrosis analysis. Atrial Rac 1, sodium calcium exchanger (INCX), sarcoplasmic reticulum calcium ATPase (SERCA), endothelial nitric oxide synthase (eNOS) and induced nitric oxide synthase (iNOS) were measured. AF inducibility, AF duration and LA fibrosis were significantly higher in the MI group (p < 0.001 vs. sham), which were significantly reduced by simvastatin (p < 0.05 vs. MI). The reduced expressions of atrial eNOS, SERCA, thrombomodulin, tissue factor pathway inhibitor and tissue plasminogen activator in the MI group were significantly improved by simvastatin. Furthermore, the increased expression of atrial iNOS, INCX and Rac1 activity were significantly decreased by the simvastatin. Oxidative stress, endothelial dysfunction and thrombogenicity are associated with the promotion of AF in a rat model of ischemic HF. These were associated with increased Rac1 activity, and simvastatin treatment prevents these changes.


Subject(s)
Atrial Fibrillation/drug therapy , Heart Failure/drug therapy , Oxidative Stress/drug effects , Simvastatin/therapeutic use , Animals , Atrial Fibrillation/metabolism , Blotting, Western , Echocardiography , Heart Failure/metabolism , Immunohistochemistry , Male , Nitric Oxide Synthase Type II/metabolism , Nitric Oxide Synthase Type III/metabolism , Rats , Rats, Sprague-Dawley
17.
EuroIntervention ; 9(9): 1085-94, 2014 Jan 22.
Article in English | MEDLINE | ID: mdl-24064426

ABSTRACT

AIMS: Angiographic evidence of edge dissections has been associated with a risk of early stent thrombosis. Optical coherence tomography (OCT) is a high-resolution technology detecting a greater number of edge dissections--particularly non-flow-limiting--compared to angiography. Their natural history and clinical implications remain unclear. The objectives of the present study were to assess the morphology, healing response, and clinical outcomes of OCT-detected edge dissections using serial OCT imaging at baseline and at one year following drug-eluting stent (DES) implantation. METHODS AND RESULTS: Edge dissections were defined as disruptions of the luminal surface in the 5 mm segments proximal and distal to the stent, and categorised as flaps, cavities, double-lumen dissections or fissures. Qualitative and quantitative OCT analyses were performed every 0.5 mm at baseline and one year, and clinical outcomes were assessed. Sixty-three lesions (57 patients) were studied with OCT at baseline and one-year follow-up. Twenty-two non-flow-limiting edge dissections in 21 lesions (20 patients) were identified by OCT; only two (9%) were angiographically visible. Flaps were found in 96% of cases. The median longitudinal dissection length was 2.9 mm (interquartile range [IQR] 1.6-4.2 mm), whereas the circumferential and axial extensions amounted to 1.2 mm (IQR: 0.9-1.7 mm) and 0.6 mm (IQR: 0.4-0.7 mm), respectively. Dissections extended into the media and adventitia in seven (33%) and four (20%) cases, respectively. Eighteen (82%) OCT-detected edge dissections were also evaluated with intravascular ultrasound which identified nine (50%) of these OCT-detected dissections. No stent thrombosis or target lesion revascularisation occurred up to one year. At follow-up, 20 (90%) edge dissections were completely healed on OCT. The two cases exhibiting persistent dissection had the longest flaps (2.81 mm and 2.42 mm) at baseline. CONCLUSIONS: OCT-detected edge dissections which are angiographically silent in the majority of cases are not associated with acute stent thrombosis or restenosis up to one-year follow-up.


Subject(s)
Coronary Vessels/pathology , Coronary Vessels/surgery , Drug-Eluting Stents/adverse effects , Tomography, Optical Coherence , Aged , Angioplasty, Balloon, Coronary , Coronary Restenosis/etiology , Female , Humans , Male , Middle Aged , Thrombosis/etiology , Tomography, Optical Coherence/methods , Treatment Outcome
18.
Eur Heart J ; 35(12): 795-807, 2014 Mar.
Article in English | MEDLINE | ID: mdl-24132187

ABSTRACT

OBJECTIVES: The purpose of this study was to assess the occurrence, predictors, and mechanisms of optical coherence tomography (OCT)-detected coronary evaginations following drug-eluting stent (DES) implantation. BACKGROUND: Angiographic ectasias and aneurysms in stented segments have been associated with a risk of late stent thrombosis. Using OCT, some stented segments show coronary evaginations reminiscent of ectasias. METHODS: Evaginations were defined as outward bulges in the luminal contour between struts. They were considered major evaginations (MEs) when extending ≥3 mm along the vessel length, with a depth ≥10% of the stent diameter. A total of 228 patients who had sirolimus (SES)-, paclitaxel-, biolimus-, everolimus (EES)-, or zotarolimus (ZES)-eluting stents implanted in 254 lesions, were analysed after 1, 2, or 5 years; and serial assessment using OCT and intravascular ultrasound (IVUS) was performed post-intervention and after 1 year in 42 patients. RESULTS: Major evaginations occurred frequently at all time points in SES (∼26%) and were rarely seen in EES (3%) and ZES (2%, P = 0.003). Sirolimus-eluting stent implantation was the strongest independent predictor of ME [adjusted OR (95% CI) 9.1 (1.1-77.4), P = 0.008]. Malapposed and uncovered struts were more common in lesions with vs. without ME (77 vs. 25%, P < 0.001 and 95 vs. 20%, P < 0.001, respectively) as was thrombus [49 vs. 14%, OR 7.3 (95% CI: 1.7-31.2), P = 0.007]. Post-intervention intra-stent dissection and protrusion of the vessel wall into the lumen were associated with an increased risk of evagination at follow-up [OR (95% CI): 2.9 (1.8-4.9), P < 0.001 and 3.3 (1.6-6.9), P = 0.001, respectively]. In paired IVUS analyses, lesions with ME showed a larger increase in the external elastic membrane area (20% area change) compared with lesions without ME (5% area change, P < 0.001). CONCLUSION: Optical coherence tomography-detected MEs are a specific morphological footprint of early-generation SES and are nearly absent in newer-generation ZES and EES. Evaginations appear to be related to vessel injury at baseline; are associated with positive vessel remodelling; and correlate with uncoverage, malapposition, and thrombus at follow-up.


Subject(s)
Coronary Disease/pathology , Coronary Vessels/pathology , Drug-Eluting Stents , Female , Humans , Male , Middle Aged , Non-Randomized Controlled Trials as Topic , Prospective Studies , Tomography, Optical Coherence , Tubulin Modulators/administration & dosage , Ultrasonography, Interventional , Vascular Remodeling/drug effects
19.
Echocardiography ; 30(9): 1042-50, 2013 Oct.
Article in English | MEDLINE | ID: mdl-23822568

ABSTRACT

Chronic right ventricular apical (RVA) pacing can lead to an increased risk of heart failure and atrial fibrillation, but the acute effects of RVA pacing on left atrial (LA) function are not well known. Twenty-four patients with sick sinus syndrome and intact intrinsic atrioventricular conduction were included. All patients received dual-chamber pacemaker implants with the atrial lead in the right atrial appendage and the ventricular lead in the right ventricular (RV) apex. Transthoracic standard and strain echocardiography (measured by tissue Doppler imaging and speckle tracking image) were performed to identify functional changes in the left ventricle (LV) and LA before and after 1 hour of RVA pacing. The LA volume index did not change after pacing; however, the ratio of peak early diastolic mitral flow velocity (E) to peak early diastolic mitral annular velocity (Ea) was significantly increased and peak systolic LA strain (Sm), mean peak systolic LA strain rate (SmSR), peak early diastolic LA strain rate (EmSR), and peak late diastolic LA strain rate (AmSR) were significantly reduced after RV pacing. LV dyssynchrony, induced by RV pacing, had a significant correlation with E/Ea, Sm, and SmSR after pacing. E/Ea also had a negative correlation with Sm and SmSR after pacing. Multivariate regression analysis identified LV dyssynchrony and E/Ea as important factors that affect Sm, SmSR, EmSR, and AmSR after acute RVA pacing. Acute RVA pacing results in LA functional change and LV dyssynchrony and higher LV filling pressures reflected by E/Ea are important causes of LA dysfunction after acute RVA pacing.


Subject(s)
Cardiac Resynchronization Therapy/adverse effects , Heart Atria/diagnostic imaging , Heart Atria/physiopathology , Heart Ventricles/diagnostic imaging , Heart Ventricles/physiopathology , Sick Sinus Syndrome/physiopathology , Sick Sinus Syndrome/therapy , Aged , Elastic Modulus , Elasticity Imaging Techniques/methods , Female , Humans , Male , Reproducibility of Results , Sensitivity and Specificity , Sick Sinus Syndrome/diagnostic imaging , Treatment Outcome
20.
J Cardiovasc Ultrasound ; 20(1): 37-41, 2012 Mar.
Article in English | MEDLINE | ID: mdl-22509437

ABSTRACT

BACKGROUND: Left atrial appendage (LAA) anatomy and function have been well characterized both in healthy and diseased people, whereas relatively little attention has been focused on the right atrial appendage (RAA). We sought to evaluate RAA flow velocity and to compare these parameters with LAA indices and with a study of biomarkers, such as brain natriuretic peptide, among patients with sinus rhythm (SR) and atrial fibrillation (AF). METHODS: In a series of 79 consecutive patients referred for transesophageal echocardiography, 43 patients (23 with AF and 20 controls) were evaluated. RESULTS: AF was associated with a decrease in flow velocity for both LAA and RAA [LAA velocity-SR vs. AF: 61 ± 22 vs. 29 ± 18 m/sec (p < 0.01), RAA velocity-SR vs. AF: 46 ± 20 vs. 19 ± 8 m/sec (p < 0.01)]. Based on simple linear regression analysis, LAA velocity and RAA velocity were positively correlated, and RAA velocity was inversely correlated with brain natriuretic peptide (BNP). CONCLUSION: AF was associated with decreased RAA and LAA flow velocities. RAA velocity was found to be positively correlated with LAA velocity and negatively correlated with BNP. The plasma BNP concentration may serve as a determinant of LAA and RAA functions.

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