Diastolic heart failure or heart failure with a normal ejection fraction

Nearly half of patients with symptoms of heart failure are found to have an left ventricular (LV) ejection fraction which is within normal limits. These patients have variously been labeled as having diastolic heart failure, heart failure with preserved LV function or heart failure with normal ejection fraction (HFNEF). Since recent studies have shown that systolic function is not entirely normal in these patients, HFNEF is the better term. More common in elderly females it has a mortality similar to heart failure with a reduced ejection fraction (HFREF). The exact pathophysiology of the symtpoms is still not clear and, therefore, debated. As heart failure is often episodic, the underlying abnormal mechanisms may not be completely apparent at rest. It is likely there is a mixture of systolic and diastolic dysfunction which will be different to some degree in individual patients and isolated diastolic dysfunction or primary abnormalities of relaxation are probably extremely rare. The main difference between HFNEF and HFREF is the degree of ventricular remodeling with increased ventricular volumes in HFREF. The time course of remodeling depends to some extent on the aetiology being quicker post myocardial infarction--the commonest cause of HFREF, and slower with hypertension which is the most frequent aetiological factor in HFNEF. Ventricular volumes rather than ejection fraction or the concept of a pure diastolic abnormality can be used to classify patients in a more rational manner.

Prevalence of amiodarone-related hepatotoxicity in 720 Chinese patients with or without baseline liver dysfunction

BACKGROUND

The prevalence of hepatotoxicity after longterm oral amiodarone therapy in Chinese patients with or without elevated liver enzymes at baseline is unknown.

HYPOTHESIS

Amiodarone may still be safely prescribed for Chinese patients who have baseline liver dysfunction.

METHODS

This is a retrospective cross-sectional study. Significant liver dysfunction (SLD) was defined as alanine aminotransferase (ALT) > 2 times upper limit of normal range.

RESULTS

Baseline liver function was checked in 628 of the 720 Chinese patients identified. The mean duration of amiodarone use was 615.9 +/- 703.1 days. Ninety patients (14.3%) had elevated baseline ALT. The prevalence of SLD was 3.7% (confidence interval [CI] 2.1-5.3%) and 4.4% (CI 0.2-8.6%) in patients with normal (n = 538) and elevated (n = 90) baseline ALT, respectively (p = 0.765). Therapy was continued in 42 patients with elevated baseline ALT until final follow-up. Eight of these (19.0%) had elevated ALT upon final follow-up, but the derangement was mild (mean ALT 134.8 +/- 145.9 IU/l, median 76 IU/l). During follow up, 24 patients developed SLD and half of these subsequently withdrew from therapy. The ALT levels at final follow-up had improved over time in both groups, but the mean difference was not significant (255.1 +/- 706.4 vs. 131.0 +/- 207.5 IU/l, p = 0.312).

CONCLUSION

The prevalence of SLD in Chinese patients taking oral amiodarone with or without elevated baseline ALT was similar (4.4 vs. 3.7%). It seems that amiodarone may be safely prescribed in patients with elevated baseline ALT.

Systolic Dysfunction in Heart Failure with a Normal Ejection Fraction: Echo-Doppler Measurements

Heart failure with a normal ejection fraction, also called heart failure with preserved ejection fraction or diastolic heart failure, is thought to be characterized by normal systolic function and disturbed diastolic function only. However, studies using newer Doppler-echocardiographic techniques have shown that ventricular function is not normal particularly in the long axis. Ejection is relatively preserved because of increased radial function. Similar findings are seen with normal ageing and the typical precursors of heart failure with a normal ejection fraction such as hypertension, diabetes, and ischemia. There appears to be a spectrum of abnormalities of systolic function from the truly normal to systolic heart failure with heart failure with a normal ejection fraction occupying an intermediate position. The use of ejection fraction, which has a normal distribution, to dichotomize patients with heart failure is not supported on theoretical or experimental grounds, and any cutoff is arbitrary. Patients with heart failure have a mixture of systolic and diastolic abnormalities and variable degrees of remodeling. It is more important to correctly identify these in the individual patient.

Repair of Infarcted Myocardium by an Extract of Geum japonicum with Dual Effects on Angiogenesis and Myogenesis

Background: It has become apparent recently that cardiac myocytes can divide after myocardial infarction, a circumstance that challenges the orthodox view that myocytes may be terminally differentiated. Replacement of the necrosed heart tissue by newly regenerated functional myocardium is a therapeutic ideal, but attempts to reconstitute functional myocardia and coronary vessels have been less successful.

Methods: We isolated a fraction containing 5 compounds from the Chinese herb Geum japonicum, which stimulates the processes of angiogenesis and cardiomyogenesis. We investigated these dual properties in both ex vivo and in vivo systems.

Results: We observed that this bioactive fraction displayed favorable dual actions on early angiogenesis and cardiomyogenesis in acute myocardial infarction in an animal model. Our results demonstrated that application of this bioactive fraction showed pronounced effects on limiting infarct size by 35%–45%, stimulating early development of new blood vessels in 24 h, and regenerating myocardium, replacing ∼49% of the total infarction volume after 2 weeks. Echocardiographic studies demonstrated marked improvement of left ventricular function within 2 days after infarction, and the improvement was sustained for >1 month.

Conclusions: The properties of this bioactive fraction appear to be entirely novel and represent a new approach for the treatment of ischemic heart disease.

Troponin T, left ventricular mass, and function are excellent predictors of cardiovascular congestion in peritoneal dialysis

Patients on maintenance peritoneal dialysis (PD) are frequently complicated with volume overload. In this study, we sought to evaluate troponin T testing alone or in combination with echocardiographic measures in predicting cardiovascular congestion in PD patients. This was a prospective study of 222 chronic PD patients with echocardiography and measurement of serum troponin T carried out at baseline. Patients were followed for 3 years or until death. The end point was first episode of cardiovascular congestion. Troponin T emerged as an independent predictor of cardiovascular congestion (hazard ratio, 2.98, 95% confidence intervals (CI), 1.19-7.42) in a multivariable Cox regression model, including also left ventricular mass index (LVMi) and ejection fraction (EF). Patients with troponin T>median (0.06 microg/l) and EF<or=50% and patients with troponin T>median but EF>50% had a 3.10-fold (95% CI, 1.71-5.63) and 1.88-fold (95% CI, 1.05-3.38) adjusted risk of cardiovascular congestion, respectively, than those with troponin T<or=median and EF>50%. Patients with troponin T>median and LVMi>or=median (96.23 g/m2.7) had a 2.68-fold (95% CI, 1.39-5.19) adjusted risk of cardiovascular congestion than those with troponin T<or=median and LVMi <median. In conclusion, troponin T predicts cardiovascular congestion in chronic PD patients without acute myocardial ischemia and provides incremental prognostic value for cardiovascular congestion when used in combination with LVM and EF. This easily available parameter adds significant value to echocardiography in identifying PD patients at risk of cardiovascular congestion.

Understanding nonresponders of cardiac resynchronization therapy--current and future perspectives

INTRODUCTION

Cardiac resynchronization therapy (CRT) is now an established nonpharmacologic therapy for advanced heart failure with electromechanical delay. Despite compelling evidence of the benefits of CRT, one troubling issue is the lack of a favorable response in about one-third of patients.

METHODS AND RESULTS

Currently, there is no unifying definition of responders, and published data were based on acute hemodynamic changes, chronic left ventricular reverse remodeling, as well as the intermediate or long-term clinical response. The lack of improvement with CRT can be due to many factors including the placement of the left ventricular pacing lead in an inappropriate location, the absence of electrical conduction delay or mechanical dyssynchrony despite wide QRS complexes, and possibly failure to optimize the CRT settings after device implantation. In acute hemodynamic studies, placing the left ventricular leads at the free wall region has been suggested to generate the best pulse pressure and positive dp/dt. The degree of mechanical dyssynchrony has recently been assessed noninvasively in CRT patients by echocardiography and in particular by tissue Doppler imaging. These studies suggested that responders of left ventricular reverse remodeling or systolic function had more severe systolic dyssynchrony. However, further studies are needed to examine the clinical utility of these parameters when applied to the standardized anatomic or functional endpoints. Optimization of atrioventricular and interventricular pacing intervals may also reduce the number of nonresponders, though newer methods, especially interventricular pacing intervals, are still under clinical investigation.

CONCLUSION

With the adjunctive use of imaging technology, physicians are able to characterize the response to CRT objectively, and cardiac imaging is an important clinical tool for determining more precisely the presence and degree of mechanical dyssynchrony.

A new function of a previously isolated compound that stimulates activation and differentiation of myogenic precursor cells leading to efficient myofiber regeneration and muscle repair

Muscle repair following severe injury is slow and incomplete due to the limited regenerative capacity of muscles comprising the function. In this study, one pure compound structurally corresponding to triterpenoid, which can directly induce the activation, proliferation and maturation of quiescent satellite cells into myocytes in vitro, was isolated from Geum japonicum. The potential effect of this compound on myogenesis was further tested in repair of severe muscle injury. It was found that this compound could significantly stimulate the regenerative potential of the damaged muscle resulting in regeneration of myotubes and myotube bundles time-dependently replacing the damaged muscle tissues. This compound-mediated active regeneration of new myofibers repairing damaged muscles was probably due to its direct action on activation and proliferation of quiescent myogenic precursor cells and enhancement of their maturation into regenerating myotubes, as was demonstrated in our primary myogenic precursor cells culture experiments. The up-regulated expression of endogenous phospho-Akt1 in compound-treated myogenic precursor cells may also contribute to the process of myofiber regeneration and muscle repair probably via promoting myogenic cell survival capacity.

Heart failure with a normal ejection fraction

Nearly half of patients with symptoms of heart failure are found to have a normal left ventricular (LV) ejection fraction. This has variously been labelled as diastolic heart failure, heart failure with preserved LV function or heart failure with a normal ejection fraction (HFNEF). As recent studies have shown that systolic function is not entirely normal in these patients, HFNEF is the preferred term. The epidemiology, aetiology and possible pathophysiology of this contentious condition are reviewed. The importance of the remodelling process in determining whether a patient presents with systolic heart failure or HFNEF is emphasised and this can be used to classify patients in a more rational manner.

Effects of Tai Chi and resistance training on cardiovascular risk factors in elderly Chinese subjects: a 12-month longitudinal, randomized, controlled intervention study

BACKGROUND

Tai Chi is rapidly gaining in popularity, worldwide. This study was performed to assess its impact on cardiovascular risk factors in comparison with resistance training exercises in elderly Chinese subjects.

METHODS

A total of 207 healthy elderly participants (65-74 years, 113/207 (55%) men) were randomly assigned to one of three intervention groups: (1) Tai Chi, three times/week for 1 h/session (n = 64); (2) resistance training exercise, three times/week for 1 h/session (n = 65); (3) usual level of physical activity control group (n = 78). Anthropometric measures, dual X-ray densitometry body composition, blood pressure, lipids, glycaemic and insulin sensitivity indices were measured at baseline and 12 months. Repeated-measures analysis of variance (anova) was used to assess the between-group changes using a last-observation-carried-forward intention-to-treat approach.

RESULTS

A total of 180 (87.0%) subjects completed the study. No significant changes were identified in the Tai Chi group compared to the resistance training or control group. Of the primary outcomes, only the improvement in the insulin sensitivity index differed, being significantly greater in the resistance training than in the control group [mean difference 0.018 (95% confidence interval ( CI) 0.000-0.037) mmol glucose/min, P = 0.02), and tending to be greater than in the Tai Chi group (mean difference 0.019 (95% CI 0.000-0.038) mmol glucose/min, P < 0.06).

CONCLUSION

Tai Chi had no significant effect on any measure compared to the controls, whereas resistance training improved the insulin sensitivity index in this 12-month study.

Tissue Doppler echocardiographic evidence of atrial mechanical dysfunction in coronary artery disease

BACKGROUND

Atrial function is an integral part of cardiac function which is often neglected. The presence of coronary artery disease (CAD) may impair atrial function. This study investigated if atrial mechanical dysfunction was present in patients with CAD by tissue Doppler echocardiography (TDI).

METHODS

Echocardiography with TDI was performed in 118 patients with CAD, and compared with 100 normal controls with comparable age and heart rate. Regional atrial function was assessed at the left (LA) and right (RA) atrial free wall and inter-atrial septum (IAS). The peak regional atrial contraction velocity of (V(A)) and the timing of mechanical events were compared.

RESULTS

The V(A) in the LA (5.0+/-2.6 Vs 7.7+/-2.6 cm/s), IAS (4.8+/-1.7 Vs 5.7+/-1.5 cm/s) and RA (6.8+/-3.1 Vs 9.2+/-2.9 cm/s) were significantly decreased in patients with CAD when compared with controls (all p<0.001). Patients with impaired systolic function (ejection fraction<or=50%) had significantly lower V(A) in the LA and IAS than those with ejection fraction>50% (both p<0.001); and were lower in those with restrictive filling pattern (RFP) than non-RFP of diastolic dysfunction (both p<0.05). The V(A) in all the subgroups was lower than controls. In contrast, transmitral atrial velocity was unable to reveal any abnormality except in the subgroup with a RFP. The LA dimension, area and volume were increased in the disease groups, but were largely unchanged in the RA despite abnormal V(A). The physiological inter-atrial delay for the onset and peak atrial contraction between the RA and LA were unaffected by CAD.

CONCLUSIONS

The atrial contractile function in both atria was impaired in the presence of CAD, especially in the LA. This was detected even in patients with preserved systolic function or mild diastolic dysfunction such as non-RFP. Direct assessment of atrial velocity by TDI may better reflect atrial mechanical function than transmitral atrial velocity.

Enhanced fusion of myoblasts with myofibers for efficient gene delivery induced by a partially purified protein fraction from rat muscle extract

The biggest challenge to gene therapy is how to efficiently deliver the desired therapeutic gene into a sufficient number of recipient cells to achieve significant clinical efficacy. Here, we identified a partially purified extract from rat muscle probably containing myoblast specific fusion factor(s) (MSF), which significantly enhanced fusion of donor myoblast with host muscle fibers. Once incorporated, the introduced genetic construct could instruct the machinery of the hybrid cells to express the desired protein(s). Rat satellite cells containing a plasmid carrying a marker bone morphogenetic protein-4 (BMP-4) coding sequence were used as foreign gene delivery vehicle. BrdU labeling of the MSF-pretreated satellite cells allowed tracing the fate of the genetically modified satellite cells in the host muscles. Immunohistochemistry using anti-BMP-4 antibody demonstrated the translation of the introduced gene construct. It was demonstrated that in the presence of MSF, numerous BrdU positive nuclei and the expression of BMP-4 polypeptides could be observed in host hybrid fibers, while in the control group using rat serum to replace MSF containing fraction, only a few BrdU positive signals were detected. The expression of osteocalcin and the elevated alkaline phosphatase activity detected in the hybrid fibers indicated the proper folding, secretion and, post-translational modification of the expressed foreign protein. This strategy of enhanced myoblast-mediated gene transfer would break the major barrier in current practice of normal or engineered myoblast transplantation in the management of genetic muscle diseases or systemic genetic disorders.

Strain Rate Imaging Differentiates Transmural From Non-Transmural Myocardial Infarction

OBJECTIVES

The aim of this study was to determine if strain rate imaging (SRI) correlates with the transmural extent of myocardial infarction (MI) measured by contrast-enhanced magnetic resonance imaging (Ce-MRI).

BACKGROUND

Identification of the transmural extent of myocardial necrosis and degree of non-viability after acute MI is clinically important.

METHODS

Tissue Doppler echocardiography with SRI and Ce-MRI were performed in 47 consecutive patients with a first acute MI between days 2 and 6 and compared to 60 age-matched healthy volunteers. Peak myocardial velocities and peak myocardial deformation strain rates were measured. Location and size of the infarct zone was confirmed by Ce-MRI using the delayed enhancement technique with a 16-segment model.

RESULTS

Contrast-enhanced MRI identified transmural infarction in 21 patients, non-transmural infarction in 15 (mean transmurality of infarct 72.3 +/- 10.6%), and another 11 patients with subendocardial infarction (<50% transmural extent of the left ventricular wall). Peak systolic strain rate (SRs) of the transmural infarction segments was significantly lower compared to normal myocardium or with non-transmural infarction segments (both p < 0.0005). A cutoff value of SRs >-0.59 s(-1) detected a transmural infarction with high sensitivity (90.9%) and high specificity (96.4%), and -0.98 s(-1) >SRs >-1.26 s(-1) distinguished subendocardial infarction from normal myocardium with a sensitivity of 81.3% and a specificity of 83.3%.

CONCLUSIONS

Peak myocardial deformation by SRI can differentiate transmural from non-transmural MI, and it allows noninvasive determination of transmurality of the scar after MI and thereby the extent of non-viable myocardium.

Effects of cardiac resynchronization therapy on incidence of atrial fibrillation in patients with poor left ventricular systolic function

Although the beneficial role of cardiac resynchronization therapy (CRT) in selected patients with heart failure is well proven, its effect on the incidence of atrial fibrillation (AF) is unclear. The present study compared the incidence of AF in 36 consecutive patients with chronic heart failure receiving CRT with its incidence in controls matched for age, gender, and left ventricular ejection fraction but not receiving CRT. The findings suggest that patients with CRT had a significantly lower incidence of AF than controls. Further studies to establish the role of CRT in preventing AF and its mechanisms are warranted.

Prolongation of atrial effective refractory period with biatrial nonexcitatory stimulation

BACKGROUND

A nonexcitatory, nonpropagating atrial extrastimulus delivered in the refractory period of the preceding cycle can prolong the atrial effective refractory period (AERP) and prevent the induction of atrial fibrillation by another AE introduced in the vulnerable period. Whether the effect of this nonexcitatory stimulation (NE) is confined only to its application site is unknown.

METHODS AND RESULTS

Sixteen consecutive patients were recruited into the study and 2 patients were excluded because of development of more sustained atrial fibrillation. NE was commenced by introduction of a 2.0 msec, 20-mA impulse at 50 msec after the preceding captured pacing impulse. AERP of right atrial septum, a distant site to NE application, was determined at baseline and after 5 minutes of steady pacing at six different protocols: protocol 1, 2, and 3 were conventional pacing at high right atrium, distal coronary sinus, and biatrial sites, respectively, and protocol 4, 5, and 6 were conventional pacing together with NE applied to the same sites as protocol 1, 2, and 3. Biatrial NE (protocol 6 with median AERP = 212.5 msec) significantly prolonged AERP compared with baseline (median AERP = 202.5 msec and P < 0.05), conventional pacing (protocol 1, 2, and 3 with median AERP = 205.0 msec, 205.0 msec, and 205.0 msec, respectively, and all P < 0.05), and single-site NE (protocol 4 and 5 with median AERP = 207.5 msec and 207.5 msec, respectively, and both P < 0.05).

CONCLUSION

Biatrial NE resulted in AERP prolongation even at sites distant to NE application. The study result suggests that by adding NE to multi-sites pacing for atrial fibrillation prevention may have additional benefit.

Do metoprolol and carvedilol have equivalent effects on diurnal heart rate in patients with chronic heart failure?

BACKGROUND

Carvedilol exerted a greater reduction in mortality than metoprolol tartrate in the Carvedilol or Metoprolol European Trial (COMET). However, it is unclear if the degree and time course of beta1-blockade during a 24-h period was similar with each agent at the doses used. Therefore we analyzed 24-h ECG Holter recordings from a study which compared the long-term clinical efficacy of metoprolol tartrate to carvedilol in chronic heart failure patients using the same dosing regimen as in COMET.

METHODS AND RESULTS

Fifty-one patients with chronic heart failure with a mean LVEF 26+/-1.8% were randomized in a double-blind fashion to receive metoprolol tartrate 50 mg bid or carvedilol 25 mg bid. 24-h ECG monitoring (Holter) was performed at baseline, 12 weeks and 1 year. Adequate quality recordings for analysis were obtained from 43 subjects at baseline, 42 at 12 weeks and 29 subjects at 1 year. Both drugs produced a fall in average 24-h heart rate from baseline at 12 weeks and at 1 year: metoprolol 88+/-3 to 71+/-2 and 69+/-3 bpm; carvedilol 83+/-3 to 70+/-2 and 70+/-3 bpm respectively (all p<0.001). The pattern of suppression of heart rate during the 24-h period was similar for both drugs.

CONCLUSION

Metoprolol tartrate 50 mg bid and carvedilol 25 mg bid had similar effects on 24-h heart rate. This result suggests that the degree of beta1-blockade produced by these two drugs in these doses is comparable and the superior survival effect of carvedilol compared to metoprolol seen in COMET is likely to be due to actions of carvedilol other than beta1-blockade.

Stent restenosis in a Chinese population

BACKGROUND

Stents are now widely used in Hong Kong and China and there is a clinical impression that restenosis is less common because of the lower prevalence of coronary artery disease and associated risk factors in the Chinese. However, there are no published data on angiographic stent restenosis rates in Chinese patients.

METHOD

In a prospective study of 114 consecutive Chinese patients who underwent coronary stenting, quantitative coronary analyses were made at the time of stent implantation and subsequently at 6 months post-stenting (n = 97).

RESULTS

At 6 months, restenosis (> or = 50% diameter stenosis in the dilated segment) was present in 42 (43.3%) of the 97 patients and 54 (33.5%) of the total 161 lesions stented. Vessel reference diameter (VRD) of < 3 mm and stented length of > or = 18 mm were associated with higher restenosis rates (36% and 38%). Compared to those without, those with restenosis had a greater residual stenosis of 16.53+/-11.54% and smaller final minimal luminal diameter (MLD) of 2.41+/-0.49 mm, (p < 0.01 and p < 0.008 respectively). Standard coronary risk factors were not associated with a higher rate of restenosis. Lesion morphology was significantly associated with restenosis.

CONCLUSION

Coronary stenting in Hong Kong Chinese patients is associated with a restenosis rate comparable to that demonstrated in previously published trials from populations in the West.

Improvement of Serum NT-ProBNP Predicts Improvement in Cardiac Function and Favorable Prognosis After Cardiac Resynchronization Therapy for Heart Failure

BACKGROUND

Cardiac resynchronization therapy (CRT) is now an established therapy for patients with advanced heart failure with electromechanical delay, although nonresponders have been observed. Because natriuretic peptides are relevant markers to reflect the severity of heart failure and filling pressure of cardiac chambers, it may be helpful to assess the efficacy of CRT.

METHODS AND RESULTS

Forty-two patients with heart failure with QRS of >120 msec were recruited; their serial N-terminal pro-B-type natriuretic peptide (NT-proBNP) levels were measured at baseline and at 1 and 3 months after CRT. There was a reduction in NT-proBNP level 1 month after CRT (2655 +/- 2242 pg/mL vs 2149 +/- 2033 pg/mL; P = .03), which was further reduced at 3 months (1473 +/- 1786 pg/mL; P < .001 vs baseline). The reduction of NT-proBNP correlated with the change of left ventricular (LV) end-systolic volume (r = 0.53; P = .001) or LV ejection fraction ( r = -0.49; P = .002) and with improvement in exercise capacity after CRT for 3 months (r = 0.50; P = .002). The patients were classified by the degree of reduction in NT-proBNP as group 1 (reduction of > or =50% vs baseline; n = 19) and group 2 (reduction of <50% vs baseline; n = 23). The degree of LV reverse remodeling (-31.8 +/- 24.7 mL vs -12.6 +/- 19.2 mL; P = .007) and gain in LV ejection fraction (+12.5% +/- 8.8% vs +4.6% +/- 5.8%; P = .002) were significantly better in group 1 than group 2. Both the all-cause mortality rate (Log-rank chi 2 = 4.01; P = .04) and the composite end-point of mortality rate or hospitalization rate for cardiovascular causes (Log-rank chi 2 = 4.31; P = .02) were significantly lower in group 1 than in group 2.

CONCLUSION

Serial monitoring of NT-proBNP may be helpful to predict a favorable outcome after CRT. Those who had a reduction of NT-proBNP level of >/=50% were more likely to exhibit a favorable response.

Rapid analysis of fatty acid-binding proteins with immunosensors and immunotests for early monitoring of tissue injury

Fatty acid-binding protein (FABP) holds promise for early detection of tissue injury. This small protein (15kD) appears earlier in the blood than large proteins after cell damage. Combined its characteristics of high concentration tissue contents and low normal plasma values provide the possibility of a rapid rise above the respective reference values, and thus an early indication of the appearance of tissue injury. A general review was presented on the current status of different types of FABP for the detection of tissue injury in patients with myocardial injury, brain injury and also in athletes or horses with skeletal muscle injury. To take full advantage of the characteristics of the early marker FABP, rapid analysis is a crucial parameter. In this review, an overview of the development of immunoassay for the quantification of FABP in buffer, plasma or whole blood was outlined. The characteristics of different FABP immunosensors and immunotests were described. The feasibility of these immunoassays to be used in routine clinical practice and in emergency case was also discussed. Nowadays, the improved automated immunoassays (e.g. a microparticle-enhanced turbidimetric immunoassay), less time-consuming bedside immunosensors and immunotests (e.g. a one-step FABP lateral flow immunotest), are the main advance technology in point-of-care testing. With these point-of-care tests, the application of FABP as an early tissue injury marker has a great potential for many clinical purposes.

Associations of serum fetuin-A with malnutrition, inflammation, atherosclerosis and valvular calcification syndrome and outcome in peritoneal dialysis patients

BACKGROUND

Fetuin-A (alpha2-Heremans Schmid glycoprotein) has recently been identified as a circulating inhibitor of calcification and is regulated as a negative acute phase protein. However, its relationships with cardiac valvular calcification and atherosclerosis and outcome have not been evaluated in peritoneal dialysis (PD) patients.

METHOD

We performed a prospective follow-up study in 238 PD patients with echocardiography done at baseline to detect cardiac valvular calcification and biochemical analysis performed for serum fetuin-A, albumin and C-reactive protein (CRP).

RESULTS

Baseline serum fetuin-A concentration was (mean+/-SD) 0.309+/-0.068 g/l (normal range 0.4-0.95). Across the three tertiles of increasing serum fetuin-A, a significant trend effect was observed for age (P = 0.023), diabetes (P = 0.008), background atherosclerotic vascular disease (P = 0.010), cardiac valvular calcification (P = 0.002), serum albumin (P<0.001), subjective global assessment (P = 0.005) and CRP (P<0.001). Adjusting for CRP and calcium x phosphorus product, every 0.01 g/l increase in serum fetuin-A remained independently associated with a 6% decrease in the risk of valvular calcification (95% confidence intervals, 0.90-0.99; P = 0.028). Furthermore, serum fetuin-A showed a significant decrease across the four groups of patients with increasing components of the malnutrition, inflammation, atherosclerosis/calcification (MIAC) syndrome (P<0.001) and was the lowest among patients with all components of the MIAC syndrome (0.263+/-0.055 g/l) and highest among those who do not have the MIAC syndrome at all (0.338+/-0.063 g/l). Lower serum fetuin-A was associated with greater all-cause mortality (P = 0.0011) and fatal and non-fatal cardiovascular events (P = 0.0017), but its significance was lost when atherosclerotic vascular disease, valvular calcification, inflammation and malnutrition were included in the model.

CONCLUSIONS

Serum fetuin-A showed important associations with valvular calcification, atherosclerosis, malnutrition and inflammation, and was linked to mortality and cardiovascular events in PD patients via its close relationships with the MIAC syndrome.

Circulating soluble vascular cell adhesion molecule 1: Relationships with residual renal function, cardiac hypertrophy, and outcome of peritoneal dialysis patients

BACKGROUND

Vascular cell adhesion molecule 1 (VCAM-1) is involved in leukocyte-endothelial cell interaction and has a pivotal role in inflammation. Whether it contributes to excessive mortality in dialysis patients remains uncertain. In this study, we examined circulating soluble VCAM-1 (sVCAM-1) in relation to different clinical and biochemical parameters, as well as mortality and cardiovascular events, in peritoneal dialysis (PD) patients.

METHODS

Values for serum sVCAM-1, together with C-reactive protein (CRP), homocysteine, albumin, lipid profile, blood hemoglobin, and indices of dialysis adequacy, were determined at study baseline, and echocardiography was performed in 160 long-term PD patients. Patients were followed up for a mean of 35 +/- 16 (SD) months.

RESULTS

Serum sVCAM-1 levels were elevated in our continuous ambulatory PD (CAPD) patients and showed a negative correlation with residual glomerular filtration rate (GFR; P < 0.001) and low-density lipoprotein (LDL) cholesterol level (P = 0.004), but a positive correlation with left ventricular mass index (P = 0.025). Using Kaplan-Meier analysis, overall survival rates at 2 years were 96.2%, 75.2%, and 50.6% for patients in the lower, middle, and upper tertiles of sVCAM-1 levels, respectively (P < 0.0001). Fatal and nonfatal cardiovascular event-free survival rates were 58.2%, 56.9%, and 19.4% for patients in the lower, middle, and upper tertiles, respectively (P < 0.0001). Using Cox regression analysis with adjustment for confounding covariates, every 100-ng/mL increase in sVCAM-1 level was associated with 8% (95% confidence interval, 1.03 to 1.13) and 5% (95% confidence interval, 1.00 to 1.10) increases in risk for death and fatal and nonfatal cardiovascular events, respectively. Its significance for all-cause mortality remained with additional adjusting for LDL cholesterol level, but was lost when adjusting for residual GFR. Its association with cardiovascular events became insignificant when adjusting for LDL cholesterol level or residual GFR. Furthermore, patients with both sVCAM-1 and CRP levels elevated at the 50th percentile or greater were associated with the greatest death and fatal and nonfatal cardiovascular event rates compared with those with either CRP or sVCAM-1 level elevated at the 50th percentile or greater.

CONCLUSION

Circulating sVCAM-1 levels show an important link with residual renal function, LDL cholesterol level, and cardiac hypertrophy in CAPD patients. Furthermore, residual renal function, which correlates inversely with circulating sVCAM-1 level, shows an important association with all-cause mortality and cardiovascular events and displaces sVCAM-1 level from the models for all-cause mortality and future cardiovascular events in CAPD patients. Additional study is needed to explore possible mechanistic links between inflammation, soluble adhesion molecules, residual renal function, and cardiac hypertrophy in CAPD patients.

A novel tool to assess systolic asynchrony and identify responders of cardiac resynchronization therapy by tissue synchronization imaging

OBJECTIVES

This study was designed to investigate if tissue synchronization imaging (TSI) is useful to identify regional wall delay and predict left ventricular (LV) reverse remodeling after cardiac resynchronization therapy (CRT).

BACKGROUND

Echocardiographic assessment of systolic asynchrony is helpful to predict a positive response to CRT. Tissue synchronization imaging is a new imaging technique that allows quick evaluation of regional systolic delay.

METHODS

Tissue synchronization imaging was performed in 56 heart failure patients at baseline and three months after CRT. Regional wall delay was identified on TSI images and the time to regional peak systolic velocity (Ts) in LV was measured by the six-basal-six-mid-segmental model. Eight TSI parameters of systolic asynchrony were computed when Ts was measured in ejection phase or also included postsystolic shortening.

RESULTS

Severe lateral wall delay occurred in 17 patients, which predicted LV reverse remodeling (chi-square = 8.13, p = 0.004). Among the eight quantitative parameters of asynchrony, the predictive values were higher for parameters that measured Ts in ejection phase than in postsystolic shortening. The standard deviation of Ts of 12 LV segments in ejection phase (Ts-SD-12-ejection) was most powerful to predict reverse remodeling (r = -0.61, p < 0.001) and gain in ejection fraction (r = 0.53, p < 0.001). The area of the receiver-operating characteristic (ROC) curve was the largest for Ts-SD-12-ejection (0.90, p < 0.001), with a sensitivity of 87% and specificity of 81% at a cutoff of 34.4 ms. The combination of lateral wall delay with Ts-SD-12-ejection gave a sensitivity and specificity of 82% and 87%.

CONCLUSIONS

Tissue synchronization imaging allows quick evaluation of regional wall delay, and combined with Ts-SD-12-ejection provides a reliable way of predicting reverse remodeling after CRT.

Left ventricular systolic asynchrony after acute myocardial infarction in patients with narrow QRS complexes

BACKGROUND

The aim of the study was to assess the degree of left ventricular (LV) asynchrony after myocardial infarction (MI) in patients with a narrow QRS complex using tissue Doppler imaging (TDI) and correlate this with the site and extent of the infarction measured by contrast-enhanced magnetic resonance imaging (Ce-MRI).

METHODS

Echocardiography with TDI and Ce-MRI was performed within 6 days of acute MI in 47 patients and compared with 69 age-matched healthy volunteers. Regional myocardial velocities were assessed in 12 segments, and the corresponding systolic velocity (Sm), early diastolic velocity (Em), as well as the time to peak Sm (Ts) and time to peak Em (Te) were measured. To assess LV synchronicity, SDs of Ts (Ts-SD) and Te (Te-SD) of all 12 segments were computed. Location and size of infarct were confirmed by Ce-MRI with a 16-segment model.

RESULTS

All the patients had a normal QRS complex duration. The Ts-SD was significantly prolonged in the MI group when compared with controls (42.2 +/- 13.7 vs 18.0 +/- 7.0 milliseconds, P < .001). The Ts-SD was longer in patients with anterior than inferior MI (46.8 +/- 13.9 vs 34.6 +/- 8.5 milliseconds, P = .002). Stepwise multiple regression analysis revealed that infarct size was the main independent predictor of systolic asynchrony ( B = 0.79, 95% CI 0.75-1.23, P < .001). Asynchrony was not related to the transmurality of the infarction.

CONCLUSIONS

Myocardial infarction has a significant impact on LV synchronicity even in those with a narrow QRS complex. The degree of LV systolic asynchrony is mainly determined by the infarct size and not transmurality.