OBJECTIVES:This study evaluated oxidative stress in the failing ventricle in patients with dilated cardiomyopathy (DCM).BACKGROUND:Oxidative stress appears to increase in the failing myocardium and may contribute to ventricular dysfunction in patients with DCM. Tumor necrosis factor-alpha (TNF-alpha), which is expressed in the failing heart, may stimulate oxidative stress.METHODS:We measured plasma oxidized low density lipoprotein (oxLDL) by sandwich enzyme-linked immunosorbent assay using specific antibodies against oxLDL in the aortic root (AO) and the coronary sinus (CS) in control subjects (n = 8) and in 22 patients with DCM and mild congestive heart failure. We also measured the plasma levels of TNF-alpha and angiotensin II.RESULTS:There was no difference in oxLDL between the AO and CS in control subjects. In contrast, plasma oxLDL was significantly higher in the CS than the AO in patients with DCM, suggesting that the transcardiac gradient ofoxLDL reflects oxidative stress in the failing heart in these patients. Plasma TNF-alpha levels were significantly higher in the CS than the AO with a significant positive correlation of the transcardiac gradient of TNF-alpha and the transcardiac gradient of oxLDL. Moreover, a significant negative correlation existed between the transcardiac gradient of oxLDL and left ventricular ejection fraction. The transcardiac gradient of plasma oxLDL was significantly lower in 6 patients who received carvedilol than in 16 patients who did not receive carvedilol.CONCLUSIONS:These findings indicate that the transcardiac gradient of oxLDL may be a marker of oxidative stress in the heart and that left ventricular dysfunction may be partly due to the oxidative stress in patients with DCM. In addition, TNF-alpha may stimulate oxidative stress in the failing heart in patients with DCM.
OBJECTIVES:We sought to evaluate the effects of spironolactone on neurohumoral factors and left ventricular remodeling in patients with congestive heart failure (CHF).BACKGROUND:Aldosterone (ALD) promotes collagen synthesis and structural remodeling of the heart. Spironolactone, an ALD receptor antagonist, is reported to reduce mortality in patients with CHF, but its influence on left ventricular remodeling has not been clarified.METHODS:Thirty-seven patients with mild-to-moderate nonischemic CHF were randomly divided into two groups that received treatment with spironolactone (n = 20) or placebo (n = 17). We measured left ventricular volume and mass before treatment and after four months of treatment. We also measured the plasma levels of neurohumoral factors, such as atrial natriuretic peptide (ANP) and brain natriuretic peptide (BNP), as well as plasma procollagen type III aminoterminal peptide (PIIINP), a marker of myocardial fibrosis.RESULTS:Left ventricular volume and mass were significantly decreased and ejection fraction was significantly increased in the spironolactone group, while there were no changes in the placebo group. Plasma levels of ANP, BNP and PIIINP were significantly decreased after spironolactone treatment, but were unchanged in the placebo group. There was a significant positive correlation between the changes of PIIINP and changes of the left ventricular volume index (r = 0.45, p = 0.045) as well as the left ventricular mass index (r = 0.65, p = 0.0019) with spironolactone treatment.CONCLUSIONS:These findings indicate that four months of treatment with spironolactone improved the left ventricular volume and mass, as well as decreased plasma level of BNP, a biochemical marker of prognosis and/or ventricular hypertrophy, suggesting that endogenous aldosterone has an important role in the process of left ventricular remodeling in nonischemic patients with CHF.
OBJECTIVES The study evaluated the transcardiac extraction or spillover of aldosterone (ALDO) in normal subjects and in patients with congestive heart failure (CHF).BACKGROUND Aldosterone promotes collagen synthesis and structural remodeling of target organs such as the heart. Spironolactone, an ALDO receptor antagonist, has recently been reported to reduce the mortality of patients with CHF; however, the effects of spironolactone on the transcardiac gradient of ALDO have not been clarified.METHODS We measured plasma ALDO in the aortic root (AO) and coronary sinus (CS) in normal subjects and 113 consecutive CHF patients and also measured plasma procollagen type III aminoterminal peptide (PIIINP) in CS, a brochemical marker of myocardial fibrosis.RESULTS Plasma ALDO was significantly lo lower in the CS than in the AO in normal subjects (n = 15; 61.2 +/- 9.3 vs. 83.1 +/- 11.8 pg/ml, p < 0.0001). In 96 CHF patients who did not receive spironolactone, plasma ALDO was significantly lower in the CS than in the AO (59.3 +/- 3.9 vs. 73.8 +/- 4.9 pg/ml, p < 0.0001). In contrast to the difference in these 96 patients, there was no significant difference in ALDO between the AO and CS in 17 patients who received spironolactone (127.4 +/- 20 vs. 124.0 +/- 19 pg/ml, p = 0.50). Stepwise multivariate analyses showed that spironolactone therapy had an independent and significant negative relationship with the transcardiac gradient of plasma ALDO in patients with CHF. In addition, significant positive correlations were seen between the transcardiac gradient of plasma ALDO and PIIINP (r = 0.565, p < 0.0001) and the left ventricular end-diastolic volume index (r = 0.484, p < 0.0001).CONCLUSIONS These results indicate that plasma ALDO is extracted through the heart in normal subjects and in CHF patients who do not receive spironolactone and that spironolactone inhibits the transcardiac extraction of ALDO in CHF patients, suggesting that spironolactone blocks the effects of ALDO on the failing heart in patients with CHF. (C) 2000 by the American College of Cardiology.
OBJECTIVES The aim of this study was to evaluate whether repetitive measurements of plasma levels of neurohumoral factors and cytokines before and after additional treatment are useful for predicting mortality in patients with congestive heart failure (CHF). BACKGROUND Neurohumoral and immune activation play an important role in the pathophysiology of CHF. However, the effects of serial changes in these factors on the prognostic value remain unknown. METHODS We measured plasma levels of neurohumoral factors and cytokines and left ventricular ejection fraction (LVEF) before and three months after optimized treatment for CHF in 102 consecutive patients with severe CHF (New York Heart Association class III to IV) on admission to our hospital. Physicians who were blind to the plasma neurohumoral factors until study completion treated patients using standard drugs. Patients were monitored for a mean follow-up period of 807 days. RESULTS Plasma levels of neurohumoral factors, cytokines and LVEF were significantly improved three months after optimized treatment. Cardiac death occurred in 26 patients. Among 19 variables including LVEF, only a high level of brain natriuretic peptide (BNP) and interleukin-6 (IL-6) at three months after optimized treatment showed significant independent relationships by Cox proportional hazard analysis with a high mortality for patients with CHF. CONCLUSIONS These findings indicate that high plasma BNP and IL-6 levels three months after optimized treatment are independent risk factors for mortality in patients with CHF, suggesting that sustained high plasma levels of BNP and IL-6 after additional standard treatment were independent risk factors for mortality in patients with CHF despite improvements in LVEF and symptoms.
To determine the transcardiac gradient of plasma endothelin-1 (ET-1) in patients with congestive heart failure (CHF), we measured plasma levels of ET-1 in both the aortic root and the coronary sinus in 14 normal subjects and 79 consecutive patients with CHF. In normal subjects, plasma ET-1 was significantly higher in the coronary sinus than in the aortic root; these findings were also shown in patients with mild CHF, suggesting that there was ET-1 spillover across the heart. In contrast, plasma ET-1 was significantly lower in the coronary sinus than in the aortic root in patients with severe CHF, suggesting there was ET-1 extraction across the heart in patients with severe CHF. The transcardiac gradient of plasma ET-1 was correlated with the left ventricular end-diastolic volume index (r = 0.501, p <0.0001) and plasma level of procollagen type III amino terminal peptide in the coronary sinus (r = 0.54, p = 0.0008), a marker of myocardial fibrosis. Stepwise multivariate analysis showed that the transcardiac gradient of plasma ET-1 was an independent and significant relation with the left ventricular end-diastolic volume index in patients with CHF (r = 0.665, p <0.0001). These findings suggest that elevated circulating ET-1 is extracted across the failing heart with a significant correlation between the transcardiac gradient of plasma ET-1 and the left ventricular end-diastolic volume index, suggesting that ET receptors are upregulated in the failing ventricle and that the elevated circulating ET-1 might stimulate the process of left ventricular remodeling in patients with severe CHF.
Endothelin-1 (ET-1) not only causes potent vasoconstriction but also leads to fluid retention, both actions mediated by ETA- and/or ETB-receptors. Selective ETA- and combined ETA/ETB-receptor antagonists improve hemodynamics in heart failure; however, it is also important to evaluate the effects of these antagonists on urine output in heart failure. We administered an acute dose of either the selective ETA-receptor antagonist FR139317 (FR, n = 5, 1 and 3 mg/kg) or the mixed ETA/ETB-receptor antagonist TAK-044 (TAK, n = 5, 1 and 3 mg/kg) to dogs with heart failure induced by rapid ventricular pacing. Renal hemodynamic and tubular functions were subsequently investigated. FR increased urinary excretion in association with increased renal plasma flow (RPF) and glomerular filtration rate (GFR) with no significant changes in the fractional reabsorption of water distally (FRWD). In contrast, despite increased GFR, TAK did not alter urine volume or RPF with significantly increased FRWD. The increase of GFR and RPF induced by FR was significantly larger than that of TAK. These findings indicate that ETB-receptor activation may result in diuresis by renal vasodilatation and reduction of water reabsorption in the distal tubules and collecting ducts. Acute ETA-receptor antagonism may therefore be more beneficial to diuresis than dual ETA/ETB-receptor inhibition in heart failure.
Endothelin-B- (ETB) receptors located in vascular beds mainly mediate vasorelaxation, however, long-term treatment with a mixed ETA/ETB receptor antagonist has been shown to improve the survival rate of rats with heart failure in a similar way to ETA-receptor inhibitors. The inhibition of ETB-receptor-mediated action should therefore be beneficial in preventing the deterioration seen in heart failure, despite various adverse hemodynamic effects. We administered K-8794 (Kowa Co. Ltd, Japan, 2mg/kg/day, n = 6), an orally active selective ETB-receptor antagonist, to dogs with heart failure induced by rapid right ventricular pacing for 14 days, commencing 8 days after pacing. Control dogs were given a placebo (n = 6). Mean arterial pressure decreased and systemic vascular resistance increased in both groups at the end of the protocol. In the K-8794 group, however, those values were higher than in the control group. Cardiac output decreased in both groups, but there were no significant differences observed between the two groups. Plasma renin activity and aldosterone increased in both groups at the end of the protocol, however levels in the K-8794 group were significantly lower than those in the control group. In the K-8794 group, it was quite interesting to note that Na excretion and urine flow rate were higher than in the control group. Our findings thus suggest that, although ETB-receptor antagonism produces some hemodynamic disadvantages, it can successfully prevent body fluid retention through the suppression the activation the renin-angiotensin-aldosterone system in dogs with heart failure.
OBJECTIVES:To evaluate the effects of an angiotensin (Ang II) type 1 receptor antagonist on immune markers in patients with congestive heart failure (CHF).BACKGROUND:Ang II stimulates production of immune factors via the Ang II type 1 receptor in vitro, and the long-term effects of Ang II type 1 receptor antagonists on plasma markers of immune activation are unknown in patients with CHF.METHODS:Twenty-three patients with mild to moderate CHF with left ventricular dysfunction were randomly divided into two groups: treatment with Ang II type 1 receptor (candesartan cilexetil) (n = 14) or placebo (n = 9). We measured plasma levels of immune factors such as tumor necrosis factor alpha (TNFalpha), interleukin-6 (IL-6), soluble intercellular adhesion molecule-1 (sICAM-1) and soluble vascular cell adhesion molecule-1 (sVCAM-1). We also measured plasma levels of the neurohumoral factors such as atrial natriuretic peptide (ANP) and brain natriuretic peptide (BNP) and cyclic guanosine monophosphate (cGMP), a biological marker of ANP and BNP.RESULTS:Plasma levels of TNFalpha, IL-6, sICAM-1 and sVCAM-1 were increased in the 23 CHF patients compared with normal subjects and significantly decreased after 14 weeks of candesartan cilexetil treatment, but did not change in the placebo group. Plasma levels of BNP, which is a marker of ventricular injury, significantly decreased, and the molar ratio of plasma cGMP to cardiac natriuretic peptides (ANP + BNP) was significantly increased after candesartan cilexetil treatment, but did not change in the placebo group.CONCLUSIONS:These findings suggest that 14 weeks of treatment with an Ang II type 1 receptor antagonist (candesartan cilexetil) decreased plasma levels of the immune markers such as TNFalpha, IL-6, sICAM-1 and sVCAM-1 and that it improved the biological compensatory action of endogenous cardiac natriuretic peptides in patients with mild to moderate CHF.
Background—Endothelin (ET)-1 is generated from big ET-1 by endothelin-converting enzyme (ECE). Plasma big ET-1 and ET-1 levels are strongly related to survival in patents with congestive heart failure (CHF). Because selective enzymatic processing of ET-1 formation appears to be an important therapeutic target for CHF, we investigated the acute effects of a specific ECE inhibitor on cardiorenal and endocrine functions in CHF compared with those of a selective ETA receptor antagonist. Methods and Results—CHF was induced in beagle dogs by rapid right ventricular pacing (270 bpm, 14 days). Two incremental doses of a specific ECE inhibitor, FR901533, or a selective ETA receptor antagonist, FR139317 (1 and 3 mg/kg, n=8, respectively), were injected into dogs with CHF. FR901533 and FR139317 decreased mean arterial pressure and pulmonary capillary wedge pressure associated with reduction in systemic and pulmonary vascular resistance. These agents increased cardiac output but did not affect left ventricular fracti...
AIMS To evaluate the level of plasma brain natriuretic peptide as a predictor of morbidity and mortality in patients with asymptomatic or minimally symptomatic left ventricular dysfunction. METHODS We measured plasma levels of atrial natriuretic peptide, brain natriuretic peptide, norepinephrine, angiotensin II, and endothelin-1 and monitored haemodynamic parameters in 290 consecutive patients with asymptomatic or minimally and newly symptomatic left ventricular dysfunction (functional classes I-II, mean left ventricular ejection fraction=37%). All patients were followed up for a median period of 812 days. The Cox proportional hazards model was used to assess the association of variables with mortality and morbidity. RESULTS At the end of the follow-up, 24 patients had suffered cardiac death and 25 had been hospitalized for worsening heart failure during the follow-up period. Among 21 variables such as clinical characteristics, treatment, haemodynamics, and neurohumoral factors, high levels of plasma brain natriuretic peptide (P<0.0001), norepinephrine (P=0.042), left ventricular end-diastolic volume index (P=0.0035), and left ventricular end-diastolic pressure (P=0.033) were shown to be independent predictors of mortality and morbidity by stepwise multivariate analysis. Moreover, only a high level of plasma brain natriuretic peptide (P<0.0001) was shown to be an independent predictor of mortality in these patients. CONCLUSIONS These results indicate that a high plasma brain natriuretic peptide level provides information about mortality and morbidity in patients with asymptomatic or minimally symptomatic left ventricular dysfunction.
OBJECTIVES This study was done to determine the spillover and extraction of endothelin-1 (ET-1) in the peripheral circulation, and to evaluate the factors that regulate local ET-1 extraction in the peripheral circulation in patients with congestive heart failure (CHF). BACKGROUND The relationship between the spillover and extraction of the ET-1 in the peripheral circulation and systemic vascular resistance (SVR) has not been fully clarified. METHODS We measured plasma levels of ET-1 both in femoral artery (FA) and femoral vein (FV) in 93 patients with CHF. RESULTS Plasma ET-1 was significantly higher in FV than in FA in New York Heart Association (NYHA) functional class II patients, but there was no difference of ET-1 between FA and FV in functional class III patients. In patients with functional class IV, plasma ET-1 was significantly lower in FV than in FA, and SVR was significantly higher than in patients with NYHA class II or class III. Moreover, a significant positive correlation existed between plasma ET-1 extraction across the lower leg and SVR in these patients. Among the various neurohumoral factors and hemodynamics, plasma levels of ET-1, angiotensin II in the FA showed an independent and significant relationship with the plasma arteriovenous difference of ET-1 in the lower limb. CONCLUSIONS Circulating ET-1 is extracted in peripheral circulation in patients with severe CHF, suggesting the possibility of upregulation of ET receptors of vascular beds in the lower limb in these patients. The peripheral extraction of ET-1 correlates with SVR in severe CHF patients and is mainly regulated by the local ET-1 and renin angiotensin systems.