Immediate administration of mineralocorticoid receptor antagonist spironolactone prevents post-infarct left ventricular remodeling associated with suppression of a marker of myocardial collagen synthesis in patients with first anterior acute myocardial infarction.

BACKGROUND: Aldosterone (ALD) has been shown to stimulate cardiac collagen synthesis and fibroblast proliferation via activation of local mineralocorticoid receptors. In patients with acute myocardial infarction, we demonstrated that ALD was extracted through the infarct heart and extracting ALD-stimulated post-infarct left ventricular (LV) remodeling. METHODS AND RESULTS: To evaluate the effect of mineralocorticoid receptor antagonist (MRA) spironolactone on post-infarct LV remodeling, 134 patients with first anterior acute myocardial infarction were randomly divided into the MRA (n=65) or non-MRA (n=69) groups after revascularization. All patients were administered angiotensin-converting enzyme (ACE) inhibitor and study drug just after revascularization. Left ventriculography with contrast medium was performed at the acute stage and after 1 month to evaluate LV remodeling. ALD was measured at aortic root and coronary sinus. There was no difference in the baseline characteristics including infarct size and LV performance between the two groups. However, LV ejection fraction was significantly improved in the MRA group compared with that in the non-MRA group (46.0+/-0.6% to 53.2+/-0.8% versus 46.5+/-0.8% to 51.0+/-0.8%, Pinteraction=0.012). LV end-diastolic volume index was significantly suppressed in the MRA group compared with that in non-MRA group (86.5+/-1.0 to 90.6+/-2.4 versus 87.5+/-1.3 to 106.8+/-3.5 mL/m2, Pinteraction=0.002). Transcardiac extraction of ALD through the heart was significantly suppressed in the MRA group (Pinteraction=0.001), and plasma procollagen type III aminoterminal peptide level, a biochemical marker of fibrosis, was significant lower in the MRA group compared with the non-MRA group (Pinteraction=0.002). CONCLUSIONS: These findings indicate that MRA combined with ACE inhibitor can prevent post-infarct LV remodeling better than ACE inhibitor alone in association with the suppression of a marker of collagen synthesis.

Plasma oxidized low-density lipoprotein as a prognostic predictor in patients with chronic congestive heart failure.

OBJECTIVES: The aim of this study was to evaluate the relationship between plasma oxidized low-density lipoprotein (oxLDL), a marker of oxidative stress, and the prognosis of patients with chronic congestive heart failure (CHF). BACKGROUND: Oxidative stress appears to play a role in the pathophysiology of CHF. We have recently reported the usefulness of plasma oxLDL as a marker of oxidative stress in CHF patients with dilated cardiomyopathy. METHODS: We measured the plasma level of oxLDL by sandwich enzyme-linked immunosorbent assay using a specific monoclonal antibody against oxLDL in 18 age-matched normal subjects and in 84 patients with chronic CHF (New York Heart Association functional class II to IV) and monitored them prospectively for a mean follow-up period of 780 days. RESULTS: Plasma oxLDL level was significantly higher in severe CHF patients than in control subjects and mild CHF patients. A significant negative correlation existed between the plasma level of oxLDL and left ventricular ejection fraction (LVEF) and a significant positive correlation between the plasma level of oxLDL and plasma norepinephrine level. Twenty-six patients had cardiac events; 14 had cardiac death and 12 were hospitalized for heart failure or other cardiovascular events. Among 10 variables including LVEF and neurohumoral factors, only high plasma levels of brain natriuretic peptide and oxLDL were shown to be independent predictors of mortality. CONCLUSIONS: These results indicate that the plasma level of oxLDL is a useful predictor of mortality in patients with CHF, suggesting that oxidative stress plays an important role in the pathophysiology of CHF.

Transcardiac increase in tumor necrosis factor-alpha and left ventricular end-diastolic volume in patients with dilated cardiomyopathy.

BACKGROUND: It remains unclear whether tumor necrosis factor (TNF)-alpha and interleukin-6 (IL-6) are secreted from the failing heart and whether there is a relationship between the transcardiac gradients of these cytokines and left ventricular (LV) remodeling. AIMS: This study evaluated the relationship between transcardiac gradients of cytokines and LV volume and function in congestive heart failure patients with dilated cardiomyopathy (DCM). METHODS AND RESULTS: We measured the plasma levels of TNF-alpha and IL-6 in the aortic root (Ao) and the coronary sinus (CS) in 60 patients with DCM. There was no difference in plasma IL-6 between the Ao and the CS. However, the plasma TNF-alpha level was significantly higher in the CS than that in the Ao. There was a significant correlation between the transcardiac gradient of plasma TNF-alpha and the LV end-diastolic volume index (LVEDVI) and LV ejection fraction. According to stepwise multivariate analyses, the transcardiac increase of TNF-alpha showed an independent and significantly positive relationship with a large LVEDVI. CONCLUSIONS: These results indicate that the elevated plasma TNF-alpha is partly derived from the failing heart in patients with DCM and that TNF-alpha plays a potential role in structural LV remodeling in patients with DCM.

[Comparative effects of losartan and amlodipine on activities of sympathetic nerve, renin-angiotensin-aldosterone system and brain natriuretic peptide in the elderly hypertensive patients].

This study investigated the comparative effects of losartan and amlodipine on the activation of the sympathetic nervous system, renin-angiotensin-aldosterone system (R-A-A system) and brain natriuretic peptide (BNP) in patients with essential hypertension. Twenty-four elderly patients who had received more than 12 months of antihypertensive treatment with amlodipine participated in this study. The treatment regimen of 5 mg/day amlodipine was changed to 50 mg/day losartan. Plasma catecholamines (norepinephrine, epinephrine and dopamine), active renin, aldosterone and BNP concentration were measured before and after an average of 5 months of losartan treatment. After losartan treatment, blood pressures were not changed, suggesting the comparable effect of 50 mg losartan and 5 mg amlodipine on elevated blood pressure. Losartan significantly reduced norepinephrine (799 +/- 277 pg/mL vs. 692 +/- 268 pg/mL, p < 0.05) and aldosterone concentration (81.2 +/- 35.3 pg/mL vs. 55.2 +/- 17.7 pg/mL, p < 0.01), whereas there were not any changes in BNP concentrations. These findings suggested that losartan might be superior to amlodipine in prevention of chronic or intermittent sympathetic hyperactivity and enhanced R-A-A system.

Serum level of uric acid, partly secreted from the failing heart, is a prognostic marker in patients with congestive heart failure.

BACKGROUND: A recent study suggested that xanthine oxidase is activated in congestive heart failure (CHF). However, whether uric acid (UA) is secreted from the failing heart remains unknown, so it is currently unclear whether serum UA can provide prognostic information independent of brain natriuretic peptide (BNP). METHODS AND RESULTS: Serum UA was measured in the aortic root (AO) and the coronary sinus (CS) of 74 patients with CHF. The serum UA level was significantly higher in the CS than in the AO. The transcardiac gradient of UA (CS-AO) increased with the severity of CHF, inversely correlated with left ventricular ejection fraction (LVEF) and positively correlated with left ventricular end-diastolic volume index. The plasma levels of norepinephrine, BNP, UA, and LVEF were monitored prospectively in 150 CHF patients for a mean follow-up of 3 years. High plasma levels of UA (p<0.001) and BNP (p<0.001) were shown by multivariate stepwise analysis to be independent predictors of mortality. CONCLUSIONS: High plasma UA level, partly secreted from the failing heart, is a prognostic predictor independent of BNP in patients with CHF. Monitoring a combination of BNP and UA may be useful for the management of patients with CHF.

Effects of long-acting calcium channel antagonists on neurohumoral factors: comparison of nifedipine coat-core with amlodipine.

Calcium channel antagonists can induce sympathetic hyperactivity, leading to a poor prognosis for hypertensive patients. Nifedipine formulations that allow once-daily administration are now available for use in clinical practice. To compare the effects of nifedipine with those of amlodipine, we studied 36 essential hypertensive patients. Those who had been administered nifedipine sustained-release were treated with amlodipine in place of nifedipine sustained-release, and those who had been administered amlodipine were treated with nifedipine coat-core in place of amlodipine. Substitution of nifedipine sustained-release by amlodipine had no significant effect on hypertensive symptoms. However, the plasma levels of norepinephrine, renin, and aldosterone were significantly lower (p < 0.001-0.05) in patients taking amlodipine in place of nifedipine sustained-release. Substitution of amlodipine by nifedipine coat-core again had no significant effect on hypertensive symptoms. However, the plasma levels of norepinephrine, renin, and aldosterone did not change significantly after the substitution. These findings indicate that, at the effective anti-hypertensive concentrations of nifedipine coat-core and amlodipine, nifedipine coat-core may not increase sympathetic nerve activity as is observed with amlodipine. The results also suggest that the duration of action of nifedipine formulations is an important determinant for nifedipine-induced hyperactivity in the reflex sympathetic nerve and the renin-angiotensin systems.

Transcardiac gradient of aldosterone before and after spironolactone in patients with congestive heart failure.

To evaluate the transcardiac extraction of aldosterone before and after spironolactone administration to patients with congestive heart failure, we measured the plasma aldosterone in the aortic root and the coronary sinus in eight congestive heart failure patients with dilated cardiomyopathy. The plasma aldosterone level was significantly lower in the coronary sinus than in the aortic root before spironolactone administration (87.5 +/- 16 versus 62.2 +/- 11 pg/ml, p = 0.01). After chronic treatment with spironolactone, there was no significant difference in the aldosterone level between the aortic root and the coronary sinus (151 +/- 49 versus 148 +/- 48 pg/ml), and the transcardiac gradient of aldosterone (aortic root to coronary sinus) was significantly decreased (25.3 +/- 7.3 versus 3.1 +/- 4.5 pg/ml, p = 0.046). These results indicate that plasma aldosterone is extracted through the heart in congestive heart failure patients with dilated cardiomyopathy, and that spironolactone inhibits the transcardiac extraction of aldosterone in congestive heart failure patients. This suggests that spironolactone blocks the effects of aldosterone on the failing heart in congestive heart failure patients with dilated cardiomyopathy.

Effect of an angiotensin II type 1 receptor blocker, valsartan, on neurohumoral factors in patients with hypertension: comparison with a long-acting calcium channel antagonist, amlodipine.

This study compared the effects of amlodipine and valsartan on the sympathetic nervous system, the renin-angiotensin-aldosterone system, and brain natriuretic peptide, which are considered important parameters of the long-term prognosis. Seventy-three elderly patients, who had received antihypertensive treatment for more than 6 months with amlodipine, participated in this study. They were randomized to the V group (n = 36) and switched to valsartan from amlodipine, or to the A group (n = 37), which continued treatment with amlodipine. The dose of valsartan was set as that which controlled the blood pressure to the same extent as before switching. Blood samples were measured before and after 6 months of therapy. Data were analyzed by two-way analysis of variance with the Newman-Keuls test. In the V group, norepinephrine (from 597.0 +/- 52.9 to 475 +/- 43.8 pg/ml, p < 0.05) and aldosterone (from 74.5 +/- 7.0 to 53.9 +/- 5.3 pg/ml, p < 0.001) were decreased significantly after 6 months, although norepinephrine and aldosterone levels were unchanged in the A group. However, brain natriuretic peptide did not show a difference between the two groups. These findings suggested that valsartan is probably superior to amlodipine with respect to less activation of the sympathetic nervous system and preventing upregulation of the renin-angiotensin-aldosterone system.