The regulatory effect of norepinephrine on connective tissue growth factor (CTGF) and vascular endothelial growth factor (VEGF) expression in cultured cardiac fibroblasts

BACKGROUND

Connective tissue growth factor (CTGF) and vascular endothelial cell growth factor (VEGF) have been implicated as important effectors during cardiac remodeling. This study tested the hypothesis that norepinephrine (NE) induces CTGF and VEGF gene and protein expression in cardiac fibroblasts (CF) and the CTGF/VEGF complex will have an effect on angiogenesis.

METHODS AND RESULTS

Rats CF were cultured in NE (0.01 to 100 μM) for 24h. CTGF and VEGF gene expression were measured by quantitative-PCR. CTGF protein and CTGF/VEGF complex were detected by Western blot. The effect of CTGF/VEGF complex on angiogenesis was detected by endothelial cell tube formation assay. VEGF antigen level, reactive oxygen species (ROS) production were measured by ELISA and DCFH-DiOxyQ assay respectively. NE at 0.01 μM up-regulated CTGF mRNA and secretory protein expression significantly whereas at 100 μM both gene and protein were down-regulated significantly when compared with controls. At 0.01 to 0.1 μM of NE, there was no change in VEGF gene and protein level. NE at 100 μM increased VEGF gene and antigen level and ROS production significantly when compared with controls. CTGF/VEGF complex was found to inhibit the angiogenesis of endothelial cells.

CONCLUSIONS

NE regulates CTGF and VEGF expression in a dose-dependent manner and via VEGF can induce angiogenesis. This work suggests NE may have an important role in ventricular remodeling.

Heart failure in long-term peritoneal dialysis patients: a 4-year prospective analysis

BACKGROUND AND OBJECTIVES

Heart failure occurs frequently in end-stage renal disease patients. However, there are no prospective, longitudinal follow-up data on its prevalence, severity, and risk factors in long-term peritoneal dialysis (PD) patients.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

A prospective observational study was conducted in 220 long-term PD patients followed up for 4 years or until death. Echocardiography was obtained at baseline. Primary study end points were heart failure and mortality.

RESULTS

Eighty-six patients had a previous history of heart failure at study entry. The cumulative 4-year survival probability was 37.4% and 64.7% for patients with and without previous heart failure, respectively (P<0.0001). During follow-up, 87 patients (40.9%) developed heart failure, of which 53 were recurrence and 34 were new-onset heart failure. Diabetes, background atherosclerotic vascular disease, systolic hypertension, left ventricular (LV) mass index, systolic dysfunction, and hypoalbuminemia were significant risk factors predicting heart failure in the entire cohort. Diabetes and LV mass and volume index were significant predictors of new-onset heart failure. Systolic hypertension, LV volume index, and hypoalbuminemia were significant predictors of recurrent heart failure.

CONCLUSIONS

Heart failure is a highly prevalent complication in long-term PD patients and predicts adverse clinical outcomes. More attention should be focused on improving BP and volume control and identifying treatment strategies that effectively lower atherosclerotic burden and reverse LV hypertrophy, remodeling, and systolic dysfunction in PD patients.

Treatment of heart failure in long-term dialysis patients: a reappraisal

Heart failure is one of the most frequent cardiac complications in patients with end-stage renal disease receiving long-term hemodialysis or peritoneal dialysis and is associated strongly with a poor prognosis. Despite the significant morbidity and mortality associated with heart failure, there are very limited therapeutic options proved to prevent and treat heart failure in dialysis patients. This limitation largely reflects the paucity of adequately powered prospective randomized clinical trials that have examined the efficacy of different therapeutic options in long-term dialysis patients with heart failure. In this article, the second in a series discussing the management of heart failure in dialysis patients, current therapeutic options for heart failure in the maintenance dialysis population are reviewed and potential novel therapeutic options are discussed.

Reduced left atrial function on exercise in patients with heart failure and normal ejection fraction

AIMS

The cardinal symptom of heart failure with a normal ejection fraction (HFNEF) is exertional dyspnoea. The authors hypothesised that failure of left atrial (LA) compensatory mechanism particularly on exercise contributes to the genesis of symptoms in HFNEF patients.

METHODS AND RESULTS

Fifty HFNEF patients, 15 asymptomatic hypertensive subjects and 30 healthy controls underwent rest and submaximal exercise echocardiography. Rest and exercise systolic, early diastolic and late diastolic (Am) mitral annular velocities were assessed using colour tissue Doppler echocardiography. Left atrial functional reserve index was calculated. Am at rest was comparable between all three groups, but exercise Am was significantly lower in HFNEF compared with hypertensive subjects and healthy controls resulting in a lower LA functional reserve index (0.84 (1.34) vs 2.39 (1.27) and 1.81 (1.39), p<0.001). LA volume index was significantly higher in HFNEF patients (30.4 (9.2) vs 27.9 (6.3) and 23.2 (7.1) ml/m(2), p=0.002). There was a significant correlation between Am on exercise with peak VO(2) max (r=0.514, p<0.001) and E/Em on exercise (r=-0.547, p<0.001). Area under the receiver operating characteristic for Am on exercise was 0.768 (95% CI=0.660 to 0.877).

CONCLUSION

HFNEF patients have reduced LA function on exercise in addition to left ventricular systolic and diastolic dysfunctions. Reduced LA function probably contributes significantly to exercise intolerance and breathlessness in HFNEF patients.

Current perspectives on diagnosis of heart failure in long-term dialysis patients

Cardiovascular disease is highly prevalent in patients with chronic kidney failure treated using dialysis. The risk of cardiovascular events is estimated to be at least 2- to 10-fold higher in dialysis patients than in age-, race-, and sex-matched persons with normal kidney function. A significant proportion of cardiovascular events in long-term dialysis patients is caused by heart failure, and the presence of heart failure is predictive of a poor prognosis. Despite the significant morbidity and mortality associated with heart failure, very few therapeutic options are proved to prevent and treat the progression of this complication in dialysis patients. There are several potential reasons for this, chiefly reflecting both challenges with diagnosis due to the coexistence of volume overload and a paucity of adequately powered prospective randomized controlled trials that examine the efficacy of different therapeutic options in dialysis patients with cardiac disease or heart failure. Thus, unlike in the general population, very few advances have been made in managing this severe complication in dialysis patients. In this article, an overview of the prevalence, severity, and risk factors for heart failure in maintenance dialysis patients is provided and the diagnosis of heart failure in these patients is revisited.

Quality of life after percutaneous coronary intervention in the elderly with acute coronary syndrome

BACKGROUND

Health-related quality of life (HRQoL) is an important but often neglected outcome measure in acute coronary syndrome (ACS) management. The prevalence of elderly presenting with ACS and undergoing percutaneous coronary intervention (PCI) is rising. We aimed to explore the impact of PCI on health status in elderly ACS patients.

METHODS

We prospectively enrolled 624 patients admitted to our institution with ACS from February 2006 to May 2008. Short Form (SF)-36 health survey was used to assess HRQoL at baseline and 6 months. Baseline characteristics and HRQoL were compared for patients treated with PCI within 30 days of index ACS admission vs. medical therapy across 3 age groups (<60, 60-79 and ≥80 years).

RESULTS

PCI was performed in 73.6%, 55.7% and 21.3% in patients aged <60, 60-79 and older than 80 years, respectively (p<0.01). Elderly patients were more likely to be female (16.9 vs. 35.4 vs. 54.6%, p<0.01) and had more co-morbidities (p<0.01). Older patients were less likely to undergo angiography (84.8 vs. 65.2 vs. 24.8%, p<0.01). Baseline HRQoL decreased with advancing age (p<0.01). However, elderly patients who underwent PCI experienced the most improvement in physical health than younger age groups. PCI was an independent predictor (Odds Ratio = 1.79, 95% CI: 1.10-2.92) of better physical health status at 6 months.

CONCLUSION

Elderly ACS patients who underwent PCI experienced the most improvement in physical health compared to younger patients. Our findings suggest that age per se should not deter against revascularization because of potential benefits in HRQOL.

Echocardiography, dyssynchrony, and the response to cardiac resynchronization therapy

Biventricular pacing or cardiac resynchronization therapy (CRT) has been a considerable advance in the therapy of chronic heart failure. However, it is clear that not all patients benefit either in terms of symptoms or cardiac function, and some may be worsened by CRT. In this review, we consider the arguments, both clinical and economical, in favour of improved selection of patients for CRT other than those in current guidelines. It also seems clear that the fundamental mechanism of CRT is correction of dyssynchrony, and we review the various methodologies available to detect dyssynchrony. Other factors are probably also important in determining outcomes such as lead position, the extent and form of myocardial damage, optimizing pacemaker performance, and clinical expertise. The potential costs of inappropriate CRT implantation are high to our patients and to the health economy, and it behooves the cardiology community to develop better selection criteria. The current guidelines can and should be improved.

Abnormal left ventricular function occurs on exercise in well-treated hypertensive subjects with normal resting echocardiography

OBJECTIVES

This study tests the hypothesis that patients with treated hypertension with well-controlled blood pressure, without ventricular hypertrophy and normal resting echocardiography, may have abnormalities of ventricular function that are apparent only on exercise and contribute to symptoms of exertional dyspnoea.

METHODS

Patients with hypertension with well-controlled blood pressure on medication and normal baseline echocardiography underwent cardiopulmonary exercise testing to determine their peak oxygen consumption (Vo(2)(max)), followed by rest and submaxinal supine exercise echocardiography (standard, tissue Doppler and speckle tracking).

RESULTS

30 patients with treated hypertension with a history of exertional dyspnoea (mean age 71+/-8 years; 18 women) and 22 age-matched healthy controls (70+/-6 years; 16 women) had rest and exercise images of sufficient quality for analysis. Both groups had comparable standard echocardiographic findings at rest. On exercise, the patients had reduced systolic longitudinal function (reserve index 0.97+/-1.34 vs 2.32+/-1.24, p=0.001), delayed early untwisting (20.4+/-7.6 vs 30.6+/-7.8%, p=0.001) and reduced ventricular suction (velocity propagation 10.6+/-10.9 vs 24.5+/-12.2 m/s, p<0.001) compared with healthy controls, which correlated with significantly reduced Vo(2)(max).

CONCLUSION

Patients with treated hypertension with normal resting echocardiography can have exercise limitation associated with widespread systolic and diastolic left ventricular dysfunction on exercise. Normal resting echocardiography does not preclude the presence of significant functional abnormalities on exercise that can contribute to symptoms.

Left ventricular mass and volume with telmisartan, ramipril, or combination in patients with previous atherosclerotic events or with diabetes mellitus (from the ONgoing Telmisartan Alone and in Combination With Ramipril Global Endpoint Trial [ONTARGET])

The ONgoing Telmisartan Alone and in combination with Ramipril Global Endpoint Trial (ONTARGET) showed that the angiotensin receptor blocker telmisartan 80 mg was not inferior to the angiotensin-converting enzyme inhibitor ramipril 10 mg, and the combination no more effective than ramipril alone, in decreasing morbidity and mortality in patients with cardiovascular disease or high-risk diabetes. Although therapy targeting angiotensin II is known to decrease left ventricular (LV) mass and volume, the relative influence of angiotensin-converting enzyme inhibitor inhibitors and angiotensin receptor blocker, and their combination, on the heart remains unclear in this population. Magnetic resonance imaging was performed in 287 patients enrolled in ONTARGET, across 8 centers in 6 countries, at randomization and after 2-year treatment (90, 100, and 97 patients in the ramipril, telmisartan, and combination therapy groups, respectively). Baseline patient characteristics showed higher frequencies of coronary artery disease, Asian ethnicity, and use of statins and beta blockers than the main ONTARGET trial. LV mass decreased in all groups (p <0.0001 for each), but there were no significant differences in change in LV mass or volume among groups, except that LV mass index decreased more on combination versus telmisartan (p = 0.04). Key determinants of LV mass decrease were a history of hypertension (p = 0.03), baseline mass (p <0.0001), and decrease in systolic blood pressure (p <0.0001). The best magnetic resonance imaging predictor of composite events was end-systolic volume (p <0.0001). In conclusion, telmisartan and ramipril had similar effects on LV mass and volume, and combination therapy was not more effective, in high-risk patients with cardiovascular disease. These results are consistent with the major outcome findings of the main ONTARGET study.

Energy intake and expenditure profile in chronic peritoneal dialysis patients complicated with circulatory congestion

BACKGROUND

Circulatory congestion is an adverse predictor of mortality in peritoneal dialysis (PD) patients.

OBJECTIVE

This study evaluated the nutritional status, energy intake, and expenditure profile of PD patients with and without previous circulatory congestion.

DESIGN

We conducted a cross-sectional study in 244 PD patients, of whom 92 had previous circulatory congestion. We estimated dietary energy intake by using a locally validated 7-d food-frequency questionnaire and by assessing resting energy expenditure (REE) and total energy expenditure (TEE) with indirect calorimetry and a locally validated physical activity questionnaire, respectively.

RESULTS

In comparison with those without circulatory congestion, patients with previous circulatory congestion were more malnourished by subjective global assessment (59% compared with 36%; P < 0.001), had lower handgrip strength, had lower midarm muscle circumference, had lower dietary protein (0.98 +/- 0.45 compared with 1.19 +/- 0.44 g x kg(-1) x d(-1); P < 0.001), and had lower energy intake (92.5 +/- 37.0 compared with 110.9 +/- 35.7 kJ x kg(-1) x d(-1); P < 0.001) but had higher C-reactive protein (P = 0.025) and higher REE (P < 0.001). However, no difference in TEE was noted between the 2 groups, which indicated lower activity energy expenditure among patients with previous circulatory congestion. The resulting energy balance was significantly more negative for patients with previous circulatory congestion than for those without previous circulatory congestion (P = 0.050). Furthermore, the prevalence of malnutrition increased with increasing episodes of circulatory congestion (P = 0.017).

CONCLUSIONS

Patients with previous circulatory congestion had significantly more inflammation, more muscle wasting, and higher REE but lower activity energy expenditure and energy and protein intakes in keeping with an anorexia-cachexia syndrome. The mechanisms of increased REE and reduced energy intake among patients with previous circulatory congestion warrant further investigation.

Is valvular calcification a part of the missing link between residual kidney function and cardiac hypertrophy in peritoneal dialysis patients?

BACKGROUND AND OBJECTIVES

Residual renal function (RRF) predicts survival and shows an important inverse relation with cardiac hypertrophy in peritoneal dialysis (PD) patients. We hypothesized that valvular calcification and the calcification milieu may be part of the process linking loss of RRF and cardiac hypertrophy.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

A cross-sectional study was conducted by performing two-dimensional echocardiography on 230 PD patients to assess valvular calcification and left ventricular (LV) mass and collecting 24-h urine for estimation of RRF.

RESULTS

Patients having valvular calcification had lower RRF than those without. Patients with no RRF showed higher calcium-phosphorus product (Ca x P) and C-reactive protein (CRP). Using multiple logistic regression analysis, every 1-ml/min per 1.73 m(2) increase in residual GFR was associated with a 28% reduction in the risk for valvular calcification. The association was lost after additional adjustment for Ca x P and CRP. Using multiple linear regression analysis, loss of RRF showed significant association with increased LV mass index, but this association was lost after additional adjustment for CRP, Ca x P, and valvular calcification. Patients with all three calcification risk factors, namely inflammation, high CaxP, and no RRF, showed the highest prevalence of valvular calcification and had the most severe cardiac hypertrophy.

CONCLUSIONS

The association among loss of RRF, valvular calcification, and cardiac hypertrophy was closely linked to increased inflammation and high Ca x P in PD patients. These data suggest that valvular calcification and the calcification milieu are part of the processes linking loss of RRF and worsening cardiac hypertrophy in PD.

The pathophysiology of heart failure with normal ejection fraction: exercise echocardiography reveals complex abnormalities of both systolic and diastolic ventricular function involving torsion, untwist, and longitudinal motion

OBJECTIVES

The purpose of this study was to test the hypothesis that in heart failure with normal ejection fraction (HFNEF) exercise limitation is due to combined systolic and diastolic abnormalities, particularly involving ventricular twist and deformation (strain) leading to reduced ventricular suction, delayed untwisting, and impaired early diastolic filling.

BACKGROUND

A substantial proportion of patients with heart failure have a normal left ventricular ejection fraction. Currently the pathophysiology is considered to be due to abnormal myocardial stiffness and relaxation.

METHODS

Patients with a diagnosis of HFNEF and proven cardiac limitation by cardiopulmonary exercise testing were studied by standard, tissue Doppler, and speckle tracking echocardiography at rest and on submaximal exercise.

RESULTS

Fifty-six patients (39 women; mean age 72 +/- 7 years) with a clinical diagnosis of HFNEF and 27 age-matched healthy control subjects (19 women; mean age 70 +/- 7 years) had rest and exercise images of sufficient quality for analysis. At rest, systolic longitudinal and radial strain, systolic mitral annular velocities, and apical rotation were lower in patients, and all failed to rise normally on exercise. Systolic longitudinal functional reserve was also significantly lower in patients (p < 0.001). In diastole, patients had reduced and delayed untwisting, reduced left ventricular suction at rest and on exercise, and higher end-diastolic pressures. Mitral annular systolic and diastolic velocities, systolic left ventricular rotation, and early diastolic untwist on exercise correlated with peak VO(2)max.

CONCLUSIONS

In HFNEF there are widespread abnormalities of both systolic and diastolic function that become more apparent on exercise. HFNEF is not an isolated disorder of diastole.

Long-term mortality and cardiovascular risk stratification of peritoneal dialysis patients using a combination of inflammation and calcification markers

BACKGROUND

It remains unknown whether a composite of inflammation and calcification markers provides better mortality and cardiovascular risk stratification in chronic peritoneal dialysis (PD) patients.

METHODS

We performed a 4-year prospective follow-up study in 231 chronic PD patients from a single regional dialysis centre in Hong Kong. Valvular calcification was detected using echocardiography, and fasting venous blood was collected to measure a panel of inflammation markers. The patients were stratified into five groups on the basis of 0, 1, 2, 3 and all 4 inflammation and calcification risk markers, namely high C-reactive protein (CRP) (CRP in upper tertile), high interleukin-6 (IL-6) (IL-6 in upper tertile), low fetuin-A (fetuin-A in lower tertile) and valvular calcification. Study outcomes included all-cause and cardiovascular mortality and fatal or non-fatal cardiovascular events (CVEs).

RESULTS

The patients with 4, 3, 2 and 1 markers had an adjusted hazard ratio (HR) of 5.17 (95% CI, 1.81-14.77, P = 0.002), 3.38 (95% CI, 1.50-7.60; P = 0.003), 2.17 (95% CI, 0.98-4.77; P = 0.056) and 2.42 (95% CI, 1.18-4.96; P = 0.016), respectively, for mortality at 4 years than those with 0 risk marker. The adjusted HRs for fatal or non-fatal CVEs were 4.33 (95% CI, 1.70-11.03; P = 0.002), 1.60 (95% CI, 0.73-3.52; P = 0.24), 1.92 (95% CI, 0.95-3.90; P = 0.07) and 1.33 (95% CI, 0.67-2.62; P = 0.42), respectively, for patients with 4, 3, 2 and 1 markers than those with 0 risk markers.

CONCLUSIONS

A composite of inflammation and calcification markers provides long-term prognostication and identifies the sickest PD patients with the worst clinical outcomes. Since these parameters can all be obtained quite readily, our data support the adoption of a multiinflammation and calcification risk marker approach for mortality and cardiovascular risk stratification in PD patients.

Echocardiography for cardiac resynchronization therapy selection: fatally flawed or misjudged?

After the publication of the PROSPECT (Predictors of Response to CRT) trial, the use of echocardiography for the assessment of mechanical dyssynchrony and as a possible aid for selecting patients for cardiac resynchronization therapy has been heavily criticized. Calls have been made to observe the current guidelines and implant according to the entry criteria of recent major trials. However, although this approach is currently to be recommended, the attempt to identify patients who will not receive the benefits of cardiac resynchronization therapy and whose clinical condition may be worsened should continue. Devices are not analogous to drugs: initial costs are higher, complications are significant, and the device cannot readily be withdrawn. Professional resources and the costs to society are high and wasted if devices are implanted inappropriately. Rather that discarding the attempt to identify the most suitable patients pre-operatively, further work is needed to refine the techniques and new clinical trials performed. A combination of methods that include finding the site of latest mechanical activation, myocardial scar localization, and assessing venous anatomy pre-operatively may help to identify those who will not derive any benefit or be potentially worsened.

Potentially modifiable risk factors associated with myocardial infarction in China: the INTERHEART China study

BACKGROUND

Lifestyle changes associated with the rapidly developing economy increase cardiovascular disease (CVD), myocardial infarction (MI) and cardiovascular risk factors (CVRFs) in China.

OBJECTIVE

To assess and compare regionally, and with other regions of the world, distribution of the nine INTERHEART CVRFs, their relationship to MI and the CVD epidemic in China in order to determine how this may influence the future of CVD in China.

METHODS

Patients with first acute MI (n = 3030) and age- and sex-matched controls (n = 3056) were enrolled from 26 centres in China.

RESULTS

Northern Chinese had higher rates of smoking and hypertension, whereas southern Chinese reported lower fruit and vegetable intake and higher rates of depression. Compared with other regions, participants from China were older, with lower body mass index and waist to hip ratios, lower total and low-density lipoprotein cholesterol levels, ApoB lipoprotein and ApoB to ApoA-1 ratios, but higher high-density lipoprotein cholesterol and ApoA-1. All nine INTERHEART CVRFs, education and income were significantly associated with MI in the Chinese cohort. There was significant heterogeneity in the strength of association between certain CVRFs and MI for China versus other regions, with stronger associations for the Chinese for diabetes (OR 5.10 vs 2.84), depression (2.27 vs 1.37) and permanent stress (2.67 vs 2.06); and lower for the Chinese for abdominal obesity (1.33 vs 2.62) (p for heterogeneity, all <0.001).

CONCLUSIONS

Diabetes and psychosocial factors have strong associations with risk of MI in China, indicating that future increases in these risk factors with societal change in China may hasten rapid increases in CVD.

Lipid profile, plasma apolipoproteins, and risk of a first myocardial infarction among Asians: an analysis from the INTERHEART Study

OBJECTIVES

This study sought to determine the prevalence of lipid and lipoprotein abnormalities and their association with the risk of a first acute myocardial infarction (AMI) among Asians.

BACKGROUND

Patterns of lipid abnormalities among Asians and their relative impact on cardiovascular risk have not been well characterized.

METHODS

In a case-control study, 65 centers in Asia recruited 5,731 cases of a first AMI and 6,459 control subjects. Plasma levels of lipids and apolipoproteins in the different Asian subgroups (South Asians, Chinese, Southeast Asians, and Japanese) were determined and correlated with the risk of AMI.

RESULTS

Among both cases and controls, mean low-density lipoprotein cholesterol (LDL-C) levels were about 10 mg/dl lower in Asians compared with non-Asians. A greater proportion of Asian cases and controls had LDL-C </=100 mg/dl (25.5% and 32.3% in Asians vs. 19.4% and 25.3% in non-Asians, respectively). High-density lipoprotein cholesterol (HDL-C) levels were slightly lower among Asians compared with non-Asians. There was a preponderance of people with low HDL-C among South Asians (South Asia vs. rest of Asia: cases 82.3% vs. 57.4%; controls 81% vs. 51.6%; p < 0.0001 for both comparisons). However, despite these differences in absolute levels, the risk of AMI associated with increases in LDL-C and decreases in HDL-C was similar for Asians and non-Asians. Among South Asians, changes in apolipoprotein (Apo)A1 predicted risk better than HDL-C. ApoB/ApoA1 showed the strongest association with the risk of AMI.

CONCLUSIONS

The preserved association of LDL-C with risk of AMI among Asians, despite the lower baseline levels, suggests the need to rethink treatment thresholds and targets in this population. The low HDL-C level among South Asians requires further study and targeted intervention.