The effect of beta-blockers in acute heart failure according to heart rate

Background/Aims@#Beta-blockers (BBs) have been shown to improve clinical outcomes in heart failure (HF) patients. We evaluated the prescribing status of BBs in patients with HF with reduced ejection fraction (HFrEF) at discharge according to the presence or not of bradycardia, and its effect on prognosis. @*Methods@#Study data were obtained from a multicenter cohort of 3,200 patients hospitalized for HF. Patients were classified into four groups according to the presence of bradycardia and use of BBs at discharge. The primary outcome was the incidence of all-cause death during follow-up. @*Results@#Of 1,584 patients with HFrEF, 281 patients died during follow-up (median 523 days, mean 578.5 ± 429.7 days). In patients with bradycardia, the all-cause death rate did not significantly differ according to the use of BBs, but in those patients without bradycardia, the incidence of all-cause death was significantly lower in the BBs group than the no BBs group. Among these four groups, patients with heart rate (HR) ≥ 60 beats/min with no BBs group had the lowest cumulative death-free survival rate. In addition, HR ≥ 60 beats/min with BBs use was independently associated with a 31% reduced risk of all-cause death in patients with HFrEF. @*Conclusions@#BBs had a beneficial effect on clinical prognosis only in those HFrEF patients without bradycardia. Therefore, BBs should be given by clinicians to HF patients without bradycardia to improve their clinical outcomes.

The effect of beta-blockers in acute heart failure according to heart rate

Background/Aims@#Beta-blockers (BBs) have been shown to improve clinical outcomes in heart failure (HF) patients. We evaluated the prescribing status of BBs in patients with HF with reduced ejection fraction (HFrEF) at discharge according to the presence or not of bradycardia, and its effect on prognosis. @*Methods@#Study data were obtained from a multicenter cohort of 3,200 patients hospitalized for HF. Patients were classified into four groups according to the presence of bradycardia and use of BBs at discharge. The primary outcome was the incidence of all-cause death during follow-up. @*Results@#Of 1,584 patients with HFrEF, 281 patients died during follow-up (median 523 days, mean 578.5 ± 429.7 days). In patients with bradycardia, the all-cause death rate did not significantly differ according to the use of BBs, but in those patients without bradycardia, the incidence of all-cause death was significantly lower in the BBs group than the no BBs group. Among these four groups, patients with heart rate (HR) ≥ 60 beats/min with no BBs group had the lowest cumulative death-free survival rate. In addition, HR ≥ 60 beats/min with BBs use was independently associated with a 31% reduced risk of all-cause death in patients with HFrEF. @*Conclusions@#BBs had a beneficial effect on clinical prognosis only in those HFrEF patients without bradycardia. Therefore, BBs should be given by clinicians to HF patients without bradycardia to improve their clinical outcomes.

Tachycardia induced Cardiomyopathy

Recent studies on radiofrequency catheter ablation (RFCA) in atrial fibrillation show its effectiveness in heart failure (HF) patients; hence, tachycardia-induced cardiomyopathy (T-CMP) is gaining attention. Tachycardia-mediated cardiomyopathy is a reversible left ventricular (LV) dysfunction, which can be induced by any tachyarrhythmia. Early recognition of T-CMP with appropriate treatment of the arrhythmia culprit will lead to the recovery of LV function. Patients with tachycardia and LV dysfunction should be suspected of having T-CMP, with or without established etiology of HF, because T-CMP may present by itself or contribute as a co-existent component. Therapeutic options include rate control, anti-arrhythmic drugs, or catheter ablation. Unlike in animal models, clinical data on human T-CMP is limited. Hence, future research should be more focused on tachyarrhythmia-induced cardiomyopathy as its burden is increasing.

Tachycardia induced Cardiomyopathy

Recent studies on radiofrequency catheter ablation (RFCA) in atrial fibrillation show its effectiveness in heart failure (HF) patients; hence, tachycardia-induced cardiomyopathy (T-CMP) is gaining attention. Tachycardia-mediated cardiomyopathy is a reversible left ventricular (LV) dysfunction, which can be induced by any tachyarrhythmia. Early recognition of T-CMP with appropriate treatment of the arrhythmia culprit will lead to the recovery of LV function. Patients with tachycardia and LV dysfunction should be suspected of having T-CMP, with or without established etiology of HF, because T-CMP may present by itself or contribute as a co-existent component. Therapeutic options include rate control, anti-arrhythmic drugs, or catheter ablation. Unlike in animal models, clinical data on human T-CMP is limited. Hence, future research should be more focused on tachyarrhythmia-induced cardiomyopathy as its burden is increasing.

Impact of Heart Rate Reduction with Maximal Tolerable Dose of Bisoprolol on Left Ventricular Reverse Remodeling

BACKGROUND: We aimed to evaluate effect of heart rate (HR) reduction on left ventricular reverse remodeling (LVRR) in Korean patients with heart failure with reduced ejection fraction (HFrEF). METHODS: Ambulatory patients with HFrEF, who had paired echocardiograms, N-terminal prohormone brain natriuretic peptide (NT-proBNP), and global assessment score (GAS) at baseline and 6-month (n = 157), were followed up on preset treatment schedule with bisoprolol. RESULTS: The LVRR occurred in 49 patients (32%) at 6-month. In multivariable analysis, independent predictors associated with LVRR were use of anti-aldosterone agent (odds ratio [OR], 4.18; 95% confidence interval [CI], 1.80–9.71), young age (OR, 0.96; 95% CI, 0.92–0.99), high baseline HR (OR, 3.76; 95% CI, 1.40–10.10), and favorable baseline GAS (OR, 1.73; 95% CI, 1.06–2.81). Beneficial effect of bisoprolol, in terms of LVRR, NT-proBNP, and GAS, was remarkable in the high HR group (baseline HR ≥ 75 beats per minute [bpm]), which showed a large HR reduction. CONCLUSION: High baseline HR (≥ 75 bpm) showed an association with LVRR and improvement of NT-proBNP and GAS in patients with HFrEF. This seems to be due to a large HR reduction after treatments with bisoprolol. Trial registry at www.ClinicalTrials.gov, NCT00749034.

Relation of Renal Function with Left Ventricular Systolic Function and NT-proBNP Level and Its Prognostic Implication in Heart Failure with Preserved versus Reduced Ejection Fraction: an analysis from the Korean Heart Failure (KorHF) Registry

BACKGROUND AND OBJECTIVES: The relationship between ejection fraction (EF), N-terminal pro-brain natriuretic peptide (NT-proBNP) levels and renal function is unknown as stratified by heart failure (HF) type. We investigated their relation and the prognostic value of renal function in heart failure with preserved ejection fraction (HFpEF) vs. reduced ejection fraction (HFrEF). MATERIALS AND METHODS: NT-proBNP, glomerular filtration rate (GFR), and EF were obtained in 1,932 acute heart failure (AHF) patients. HFrEF was defined as EF<50%, and renal dysfunction as GFR<60 mL/min/1.73 m² (mild renal dysfunction: 30≤GFR<60 mL/min/1.73 m²; severe renal dysfunction: GFR<30 mL/min/1.73 m²). The primary outcome was 12-month all-cause death. RESULTS: There was an inverse correlation between GFR and log NT-proBNP level (r=−0.298, p<0.001), and between EF and log NT-proBNP (r=−0.238, p<0.001), but no correlation between EF and GFR (r=0.017, p=0.458). Interestingly, the prevalence of renal dysfunction did not differ between HFpEF and HFrEF (49% vs. 52%, p=0.210). Patients with renal dysfunction had higher 12-month mortality in both HFpEF (7.9% vs. 15.2%, log-rank p=0.008) and HFrEF (8.6% vs. 16.8%, log-rank p<0.001). Multivariate analysis showed severe renal dysfunction was an independent predictor of 12-month mortality (hazard ratio [HR], 2.08; 95% confidence interval [CI], 1.40–3.11). When stratified according to EF: the prognostic value of severe renal dysfunction was attenuated in HFpEF patients (HR, 1.46; 95% CI, 0.66–3.21) contrary to HFrEF patients (HR, 2.43; 95% CI, 1.52–3.89). CONCLUSION: In AHF patients, the prevalence of renal dysfunction did not differ between HFpEF and HFrEF patients. However, the prognostic value of renal dysfunction was attenuated in HFpEF patients.

Temporal Trends of Hospitalized Patients with Heart Failure in Korea

Heart failure (HF) is an important cardiovascular disease because of its increasing prevalence, significant morbidity, high mortality and rapidly expanding health care costs. The number of HF patients is increasing worldwide and Korea is no exception. Temporal trends of four representative Korean hospitalized HF registries–the Hallym HF study, the Korean Multicenter HF study, the Korean Heart Failure (KorHF) registry and the Korean Acute Heart Failure (KorAHF) registry showed mild survival improvement reflecting overall HF patient care development in Korea despite the increased severity of enrolled patients with higher incidence of multiple comorbidities. Moreover, device therapies such as implantable cardioverter defibrillator and cardiac resynchronization therapy and definitive treatment such as heart transplantation have been increasing in Korea as well. To prevent HF burden increase, it is essential to set up long term effective prevention strategies for better control of ischemic heart disease, hypertension and diabetes, which might be risk factors for HF development. Moreover, proper HF guidelines, performance measures, and performance improvement programs might be necessary to limit HF burden as well.

Toward a New Heart Failure Registry in Korea

No abstract available.

Affecting Factors of Health Behavior Adherence depending on the Duration of the Hypertension Diagnosis / 재활간호학회지

PURPOSE: This study was to analyze health behavior adherence and identify affecting factors on the duration of the hypertension diagnosis. METHODS: A total of 154 patients of hypertension participated in this study. Data were collected from October to December, 2013 and analyzed using frequency, t-test, ANOVA, multiple linear regression. RESULTS: The scores of health behavior adherence and hypertension knowledge in incidental hypertension patients were 82.23±9.69, 17.86±4.33, respectively. In the treated hypertension patients, the scores of health behavior adherence were 89.30±10.17 and hypertension knowledge were 18.54±3.89. The selected independent variables explained 34% of the health behaviors in the incidental hypertension patients and 36% of the health behaviors in the treated hypertension patients. The regression models were statistically significant (F=4.37, p < .001, F=4.45, p < .001). Among selected potential influencing factors, age (β=.423, p < .001), smoking habit (β=−.227, p=.038), obesity (β=.369, p=.030), hypertension knowledge (β=.281, p=.007), coping strategies (β=.261, p=.015). affect health behavior adherence in the incidental hypertension. In the treated hypertension patients were age (β=.362, p=.007), sex (β=−.396, p=.004), smoking habit (β=−.245, p=.022), perceived health status (β=−.238, p=.035) affect health behavior adherence. CONCLUSION: There was difference about health behavior adherence between newly diagnosed and treated hypertension patients. So different approaches for incidental and treated hypertensive patient need to improve health behavior through tailored nursing intervention.

The Prognostic Implication of Metabolic Syndrome in Patients with Heart Failure

BACKGROUND AND OBJECTIVES: Metabolic syndrome (MetS) increases the risk of heart failure (HF). The purpose of this study was to identify the prevalence of MetS in patients with HF and determine the syndrome's association with HF in clinical and laboratory parameters. SUBJECTS AND METHODS: A total of 3200 HF patients (67.6+/-14.5 years) enrolled in a nationwide prospective Korea HF Registry between Jan. 2005 and Oct. 2009. Patients were divided into two groups according to the presence or absence of MetS at admission: group I (presence, n=1141) and group II (absence, n=2059). RESULTS: The prevalence of MetS was 35.7% across all subjects and was higher in females (56.0%). The levels of white blood cells, platelets, creatinine, glucose, and cholesterol were significantly higher in group I than in group II. Left ventricular dimension and volume was smaller and ejection fraction was higher in group I than in group II. An ischemic cause of HF was more frequent in group I. The rates of valvular and idiopathic cause were lower in group I than in group II. The rate of mortality was lower in group I than in group II (4.9% vs. 8.3%, p<0.001). CONCLUSION: Despite the increased cardiovascular risks in MetS, MetS was found to be associated with decreased mortality in HF.

Physician's Awareness and Education for Patient on Life Style Modification and Home Blood Pressure Monitoring Recommended in Hypertension Guideline

BACKGROUND: It is important to understand physicians' awareness and knowledge on hypertension guideline to comprehend physician oriented barrier against proper hypertension management. Current guidelines emphasize on the role of home blood pressure monitoring. The aim of this study is to investigate the level of awareness and knowledge of Korean physicians on home blood pressure monitoring recommended in current guideline. METHODS: A questionnaire survey asking home blood pressure measurement, as well as prehypertension and life style modification, was conducted among 36 primary physicians and 25 residents of a tertiary medical center. RESULTS: Except the limitation alcohol intake (80.3%), the physicians demonstrated above 90% of agreement with other contents of life style modification recommended by published guidelines (salt restriction, stop smoking, weight loss, and regular aerobic exercise). Majority (77.7%) of primary physicians recommend home blood pressure measurement to their patients. Significantly primary physicians were likely to recommend home blood pressure monitoring than residents (48% vs. 77.7%, p = 0.027). But both physicians and residents show poor compliance to home blood pressure monitoring guideline in the point of blood pressure measuring (12% vs. 19.4%, p > 0.05). But most of participants are aware of adverse effect of prehypertension (88.5%) and the need of its treatment (96.7%). CONCLUSIONS: This result suggest screening alcohol use disorder and brief counseling by physicians should be encouraged as a part of hypertension management and promoting physicians to equip the correct knowledge of home blood pressure measuring recommended in guideline is warranted.

Slow Coronary Flow is Related to Increased Carotid Intima-Media Thickness but Not Pulse Wave Velocity

BACKGROUND AND OBJECTIVES: Slow coronary flow (SCF) is characterized by delayed contrast dye opacification without significant stenosis of epicardial coronary arteries. However, the pathophysiology and clinical implications of SCF are not fully understood. Some reports have suggested that SCF might be caused by atherosclerosis in the coronary artery microvasculature. Measuring carotid intima-media thickness (IMT) and pulse wave velocity (PWV), which are non-invasive and simple diagnostic tools, was developed to detect subclinical atherosclerosis. Thus, we determined IMT and PWV, and their possible relationship in a SCF group and a normal coronary flow (NCF) group of patients. SUBJECTS AND METHODS: We included 101 patients who complained of chest pain but had a normal coronary angiogram. Thrombolysis in Myocardial Infarction frame count (TIMI frame count, TFC) was evaluated in the left and right coronary arteries. We defined SCF as a TFC of more than 25. Carotid IMT was measured by ultrasonography in both common carotid arteries. PWV was calculated from pulse transit time between the brachial and ankle arteries. RESULTS: Fifteen patients were included in the SCF group and 86 patients in the NCF group. Male patients (n=11, 73.3%) were significantly more common in the SCF group than in the NCF group (n=37, 43.0%, p<0.05). The TFC of the SCF and NCF groups were 28.8+/-3.5 and 15.7+/-4.5, respectively. The carotid IMT in the SCF group increased significantly compared to that in the NCF group (1.2+/-0.3 mm vs. 0.8+/-0.1 mm, p<0.01). However, no significant difference in PWV was observed between the two groups. CONCLUSION: SCF may reflect early atherosclerotic changes in the coronary artery microvasculature.

Renal Dysfunction in Acute Heart Failure

During treatment of acute heart failure (AHF), worsening renal function is often complicated and results in a complex clinical course. Furthermore, renal dysfunction is a strong independent predictor of long-term adverse outcomes in patients with AHF. Traditionally, the predominant cause of renal dysfunction has been attributed to impairment of cardiac output and relative underfilling of arterial perfusion. Recently, emerging data have led to the importance of venous congestion and elevated intra-abdominal pressure rather than confining it to impaired forward cardiac output as the primary driver of renal impairment. Relief of congestion is a major objective of AHF treatment but therapy is still based on the administration of loop diuretics. The results of the recently performed controlled studies for the assessment of new treatments to overcome resistance to diuretic treatment to protect kidneys from untoward effects have been mostly neutral. Better treatment of congestion in heart failure remains a major problem.

Characteristics, Outcomes and Predictors of Long-Term Mortality for Patients Hospitalized for Acute Heart Failure: A Report From the Korean Heart Failure Registry

BACKGROUND AND OBJECTIVES: Acute heart failure (AHF) is associated with a poor prognosis and it requires repeated hospitalizations. However, there are few studies on the characteristics, treatment and prognostic factors of AHF. The aims of this study were to describe the clinical characteristics, management and outcomes of the patients hospitalized for AHF in Korea. SUBJECTS AND METHODS: We analyzed the clinical data of 3,200 hospitalization episodes that were recorded between June 2004 and April 2009 from the Korean Heart Failure (KorHF) Registry database. The mean age was 67.6+/-14.3 years and 50% of the patients were female. RESULTS: Twenty-nine point six percent (29.6%) of the patients had a history of previous HF and 52.3% of the patients had ischemic heart disease. Left ventricular ejection fraction (LVEF) was reported for 89% of the patients. The mean LVEF was 38.5+/-15.7% and 26.1% of the patients had preserved systolic function (LVEF > or =50%), which was more prevalent in the females (34.0% vs. 18.4%, respectively, p<0.001). At discharge, 58.6% of the patients received beta-blockers (BB), 53.7% received either angiotensin converting enzyme-inhibitors or angiotensin receptor blockers (ACEi/ARB), and 58.4% received both BB and ACEi/ARB. The 1-, 2-, 3- and 4-year mortality rates were 15%, 21%, 26% and 30%, respectively. Multivariate analysis revealed that advanced age {hazard ratio: 1.023 (95% confidence interval: 1.004-1.042); p=0.020}, a previous history of heart failure {1.735 (1.150-2.618); p=0.009}, anemia {1.973 (1.271-3.063); p=0.002}, hyponatremia {1.861 (1.184-2.926); p=0.007}, a high level of serum N-terminal pro-B-type natriuretic peptide (NT-proBNP) {3.152 (1.450-6.849); p=0.004} and the use of BB at discharge {0.599 (0.360-0.997); p=0.490} were significantly associated with total death. CONCLUSION: We present here the characteristics and prognosis of an unselected population of AHF patients in Korea. The long-term mortality rate was comparable to that reported in other countries. The independent clinical risk factors included age, a previous history of heart failure, anemia, hyponatremia, a high NT-proBNP level and taking BB at discharge.

Effect of Lacidipine on Blood Pressure and Endothelial Function in Mild-to-Moderate Essential Hypertension Patients With Diabetes in Korea

BACKGROUND AND OBJECTIVES: The aim of this study was to evaluate the efficacy of lacidipine in reducing blood pressure (BP) and to determine its effect on endothelial function in mild-to-moderate hypertensive patients with type 2 diabetes mellitus (DM). SUBJECTS AND METHODS: This was a prospective, multicenter, open-label, single-arm study, enrolling 290 patients with mild-to-moderate hypertension and type 2 DM. Patients were initially treated with 2 mg lacidipine orally once daily for 4 weeks, which was then increased as necessary every 4 weeks to a maximal dose of 6 mg daily. The primary endpoint was the mean change in systolic blood pressure (SBP) from baseline after 12 weeks of treatment. Secondary endpoints included mean changes in diastolic blood pressure (DBP), flow-mediated vasodilatation (FMD), and serum concentrations of biochemical markers such as high-sensitivity C-reactive protein (hs-CRP), monocyte chemo-attractant protein-1 (MCP-1), matrix metalloproteinase-9 (MMP-9), and plasminogen activator inhibitor-1 (PAI-1). RESULTS: Lacidipine treatment significantly reduced SBP by -13.4+/-13.0 mmHg (p<0.001) and DBP by -6.2+/-9.3 mmHg (p<0.001). Lacidipine treatment did not improve endothelial-dependent vasodilatation, despite significantly improved nitroglycerin-induced, endothelial-independent vasodilatation. MCP-1 levels significantly decreased from 283.66+/-110.08 pg/mL to 257.83+/-100.23 pg/mL (p<0.001); whereas there were no significant changes in the levels of hs-CRP, MMP-9, or PAI-1. CONCLUSION: Twelve weeks of treatment with lacidipine was effective and well tolerated in mild-to-moderate hypertensive patients with type 2 DM. In spite of inducing a significant reduction in MCP-1 levels, lacidipine did not improve endothelial function.

Carotid Intima-Media Thickness and Plaque as a Predictor for Ischemic Etiology in Patients With Severe Left Ventricular Systolic Dysfunction

BACKGROUND AND OBJECTIVES: Coronary artery disease (CAD) is a major cause of heart failure associated with left ventricular systolic dysfunction (LVSD). The prognosis of LVSD is significantly influenced by the etiology of heart failure and therefore, differentiation of significant CAD from other etiologies is important. Carotid intima-media thickness (IMT) and plaque are useful predictors for cardiovascular events, including stroke and CAD. The purpose of this study was to evaluate the predictive value of carotid IMT and plaque for the diagnosis of CAD in LVSD patients. SUBJECTS AND METHODS: Seventy-three (n= 73, 47 male, 67.6+/-12.4 years) patients hospitalized for heart failure with severe LVSD were retrospectively enrolled. The severity of CAD was analyzed by the Duke Jeopardy Score system, and carotid IMT and plaque were measured according to the Mannheim Carotid IMT Consensus. RESULTS: Significant CAD was found in 41 patients (56.1%, CAD group) on coronary angiography. Mean common carotid artery (CCA) IMT (0.74+/-0.05 mm vs. 1.04+/-0.04 mm, p<0.01) was significantly higher in the CAD group. Plaque in CCA (6.25% vs. 19.5%, p<0.01) and plaque in bulb (25.0% vs. 60.9%, p<0.001) were significantly higher in the CAD group. Mean CCA IMT {odds ratio (OR) 2.61, 95% confidence interval (CI) 1.134-4.469, p<0.01} and plaque in bulb (OR 4.69, 95% CI 1.702-12.965, p<0.01) were significant predictors for the diagnosis of CAD according to multivariate logistic regression analysis. CONCLUSION: In patients with severe LVSD, mean CCA IMT and bulb plaque can be useful additional predictors for the diagnosis of CAD.

Clinical Utility and Accuracy of Coaguchek(R) XS, a Reliable Alternative to Laboratory International Normalized Ratio Monitoring in Korean Patients With Atrial Fibrillation

BACKGROUND AND OBJECTIVES: To evaluate the accuracy and the clinical utility of the Coaguchek(R) XS, a portable point-of-care coagulometer, compared to standard laboratory methods in Korean patients. SUBJECTS AND METHODS: We included 107 patients with atrial fibrillation on long-term oral warfarin therapy. The prothrombin time as expressed by the international normalized ratio (INR) was measured by the portable Coaguchek(R) XS system as well as standard laboratory methods. Agreement between the two methods was defined as a difference of less than 0.3 between the INR values. RESULTS: The INR determined by the portable Coaguchek(R) XS had excellent correlation with the values obtained by standard methods (r=0.984, p3.0). There was a 91.6% agreement between the two methods. Only nine cases (8.4%) had a difference of more than 0.3; this was mainly noted in the high INR group. CONCLUSION: The portable self-testing of the INR by the Coaguchek(R) XS might be a reliable alternative to hospital based laboratory testing in Korean patients.

Changes in Left Ventricular Systolic Function According to Thrombolysis in Myocardial Infarction Frame Count Immediately After Coronary Intervention in Patients With Obstructive Coronary Artery Disease

BACKGROUND AND OBJECTIVES: Some reports have suggested that coronary microvascular dysfunction plays a role in the recovery of myocardial function in patients with obstructive coronary artery disease. Thrombolysis in myocardial infarction (TIMI) frame count (TFC) is regarded as a simple, reliable method for evaluating microvascular function. We evaluated microvascular function using TFC immediately after coronary intervention and compared TFC with left ventricular systolic function eight months later. SUBJECTS AND METHODS: We studied 68 patients with obstructive coronary artery disease who underwent coronary intervention. Just after intervention, TFC was calculated with the standard method. Left ventricular systolic function was assessed with left ventricular diastolic dimension (LVEDd), ejection fraction (EF), and wall motion score index (WMSI). Eight months after intervention, we completed follow-up coronary angiography and echocardiography. We defined high TFC (HTFC) as a TFC greater than 18. RESULTS: Ten patients were in the HTFC group, and 58 patients were in the low TFC (LTFC) group. There was no difference between the two groups with regard to baseline cardiovascular characteristics and angiographic findings. Just after intervention, the HTFC group showed significantly higher LVEDd (56.6+/-8.9 mm) and WMSI (1.60+/-0.65) compared to the LTFC group (50.3+/-5.9 mm, p0.05). Eight months after intervention, there was also a significant decrease in the WMSI in the LTFC group (1.23+/-0.25, p0.05). CONCLUSION: Increased TFC immediately after coronary intervention is an important poor prognostic factor related to myocardial systolic function eight months after coronary intervention. Coronary microvascular dysfunction may influence myocardial recovery in the setting of obstructive coronary artery disease.

Effect of Antioxidants on Myocardial Damage in Streptozotocin-Induced Diabetic Rats

BACKGROUND AND OBJECTIVES: Many diabetic patients suffer from cardiomyopathy, even in the absence of vascular disease. The aim of this study was to see if dietary antioxidant supplementation has an inhibitory effect on the progression of cardiac tissue damage in streptozotocin (STZ)-induced diabetic rats. MATERIALS AND METHODS: Sprague-Dawley male rats (n=60) were used as experimental animals; they were divided into the normal control group and the diabetic group. Eight weeks after STZ injection (65 mg/kg of body weight), the products of lipid peroxidation (malondialdehydes, MDA), and the antioxidant enzyme superoxide dismutase (SOD), and catalase activities were determined in the cardiac tissue homogenates. The cardiac tissues were studied by light microscopy (LM) and electron microscopy (EM), and the tissue lesions were graded by a semiquantitative score. RESULTS: The histologic scores for perivascular fibrosis, interstitial fibrosis and myocardial necrosis according to LM were significantly lower in the combined vitamin C & E treated rats than in the diabetic control rats. The ultrastructural scores for the overall cardiac morphology, mitochondria and myofilaments, according to EM, were significantly lower in the vitamin E treated rats and the combined vitamin C & E treated rats than in the diabetic control rats, even though this was of less magnitude than that in the insulin-treated diabetic rats. CONCLUSION: These results suggest that antioxidants such as vitamin C & E might have a beneficial effect on diabetes as an adjunct therapy against lipid peroxidation and diabetic cardiomyopathy, in addition to the effects of instituting strict measures for controlling the blood glucose.

Impact of Pulmonary Hypertension on the Regional Right Ventricular Strain

BACKGROUND AND OBJECTIVES: Evaluation of right ventricular dysfunction in patients with pulmonary hypertension is useful for clinical management and it has prognostic implications. The purpose of this study was to evaluate the impact of pulmonary hypertension on the regional strain of the right ventricle and to assess the correlation between pulmonary arterial (PA) pressure and right ventricular (RV) strain. SUBJECTS AND METHODS: A total of fiftyone patients with chronic obstructive lung disease were classified into two groups on the basis of the presence of normal PA pressure (group I, PA pressure<35 mmHg, n=22) or high PA pressure (group II, PA pressure(35 mmHg, n=29), as estimated by the peak tricuspid regurgitation velocity on Doppler echocardiography. The left ventricular (LV) ejection fraction and RV fractional area change were assessed by conventional echocardiography, and the strain values were obtained from the RV, the LV free wall and the septum. RESULTS: The baseline characteristics were similar in both groups except for the peak PA pressure (group I: 30.2+/-3.9 mmHg, group II: 44.4+/-7.5 mmHg, p<0.00001). Group II had statistically reduced basal RV strain (-%) (20.3+/-7.1) compared to group I (24.1+/-6.7, p=0.033). The basal RV strain correlated with the PA pressure (r2=0.269, p=0.004). CONCLUSION: RV strain could determine regional RV dysfunction in patients with pulmonary hypertension.