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Immunomodulatory Role of Angiotensin II on Cardiac Remodeling
S32 Journal of Cardiac Failure Vol. 12 No. 6 Suppl. 2006 101 Immunomodulatory Role of Angiotensin II on Cardiac Remodeling Qianli Yu1, Douglas F. Larson1; 1Sarver Heart Center, The University of Arizona, Tucson, AZ Background: It is established that angiotensin II (AngII) is a potent secretory factor regulating cardiac remodeling. AngII also exhibits strong immunological properties through converting naive T-lymphocytes (Th0) to a Th1 phenotype. This study investigated whether AngII immunomodulation of T-lymphocytes is involved in the cardiac remodeling process in vitro and in vivo. Objective: We hypothesized that AngII stimulation of T-lymphocytes affects the extracellular cardiac matrix (ECM) remodeling processes. Methods: Cardiac fibroblasts (CF) and splenic T-lymphocytes were harvested from C57BL/6 mice. When the CF were 90% confluent, T-lymphocytes were indirectly co-cultured with CF in a 0.4 mm inserts. AngII was administered at a final concentration of 10-8 M. The treatment groups were as follows: CF, CFþAngII, CFþTh0, and CFþTh0þAngII. AngII treatments were refreshed after 12 hours of initial treatment. After 24 hours, supernatant, lymphocytes, and CF were collected. Th0 and Th0þAngII lymphocytes were subsequently washed 5 times and adoptively transferred into C57 SCID mice at a dose of 8X106 T-cells/mouse, i.p. After 30 days the hemodynamic function was determined by conductance catheter analysis. Results: With AngII treatment, the ratio of the Th1 cytokine, IFN-g. and the Th2 cytokine, IL-10, was increased 14-fold when compared to the non-AngII treated Th0. The activity of the enzyme which causes cardiac ECM collagen crosslinking, lysl oxidase (LOX), was significantly enhanced only in the CFþTh0þAngII group by 1.9-fold when compared to non-treated CFþTh0 (P 5 0.05). The hemodynamic function in T-cell adoptively transferred SCID mice showed that AngII polarized Th0 T-lymphocytes significantly increased the heart weight to tibial length ratio by 11.3% (P 5 0.042) and spleen weight by 41.1% (P 5 0.034) compared to the TH0 only group. End diastolic volumes increased from 14.71 microliters to 17.63 microliters (P 5 0.007) and the ventricular stiffness (b) and the isovolumic relaxation (t) were decreased by 47.6% and 18.1% respectively (P 5 0.036 and 0.004) when comparing the Ang II polarized T-lymphocytes with non-polarized lymphocytes. Conclusions: AngII induces marked TH1 polarization of T-lymphocytes. This study demonstrates a direct effect of AngII treated T-lymphocytes on CF in vitro. AngII polarized T-lymphocytes adoptively transferred to naive mice facilitated cardiac remodeling processes in vivo which appeared to affect parameters associated with the cardiac ECM - that is diastolic function.
102 Intra-Renal Infusion of BNP in Experimental Heart Failure: A Novel Strategy To Maximize the Renal Enhancing Actions of BNP While Minimizing Arterial Hypotension Horng H. Chen1, John A. Schirger1, Cataliotti Alessandro1, Fernando L. Martin1, John C. Burnett1; 1Internal Medicine, Cardiovsacular Diseases, Mayo Clinic College of Medicine, Rochester, MN Background: BNP possesses systemic vasodilating, renin-inhibiting and renal excretory and hemodynamic enhancing actions. However, the renal enhancing actions of BNP may be limited by arterial hypotension when administered intravenously (IV) at high doses. We hypothesized that intra-renal (IR) administration of BNP would maximize its renal actions without systemic hypotension. To test this hypothesis we utilized an innovative bilateral renal artery catheter system for direct renal delivery of BNP in a large animal model of congestive heart failure (CHF). Methods: We defined the cardiorenal and humoral effects of intravenous (IV) (n 5 6) or IR (n 5 6) administration of canine BNP at 0.01mg/kg/min for 45 minutes in two separate groups of dogs with pacing induced overt CHF (240 bpm for 10 days). We used a small (3.1 Fr) bifurcated renal catheter (Flowmedica) for direct infusion into the renal arteries. * P!0.05. Results: IR BNP resulted in natriuresis (4 6 2 to 50 6 11 mEq/min*), diuresis (0.2 6 0.1 to 16 0.3 ml/min*) with an increase in glomerular filtration rate (GFR: 26 6 6 to 38 6 5 ml/min*) and renal blood flow (RBF: 175 6 15 to 198 6 14 ml/min*) with suppression of plasma renin activity* and angiotensin II*. Importantly, IR BNP did not result in a decrease in mean artery blood pressure (MAP: from 98 6 2 to 99 6 1 mmHg PO0.05). These renal enhancing actions were associated with increased delivery of BNP to the kidney as evident by increased urinary BNP excretion (24 6 10 to 70 6 10 pg/min*) in association with a decrease in distal reabsorption of sodium, a nephron site abundant with natriuretic peptide receptors. In contrast, IV BNP significantly decreased MAP (from 100 6 3 to 91 6 5 mmHg*) with significantly reduced renal enhancing actions as compared to IR BNP. Conclusion: In overt experimental CHF, IR BNP maximized the renal enhancing actions of BNP in the absence of changes in MAP. Therefore IR BNP is a novel strategy to increase local delivery of BNP to the kidneys without the systemic side effects of arterial hypotension.
103 Serum Procollagen Peptides Are Similar in Mildly and Severely Symptomatic Patients with Heart Failure Vicki L. Groo1, Kathryn M. Momary1, Thomas D. Stamos2, Joseph R. Camp1, Larisa H. Cavallari1; 1Department of Pharmacy Practice, University of Illinois at Chicago, Chicago, IL; 2Division of Cardiology, University of Illinois at Chicago, Chicago, IL. Background: Spironolactone is an aldosterone antagonist that attenuates cardiac fibrosis and improves survival in patients with severe heart failure; however, its
benefits in less severe heart failure are unknown. In a subpopulation of the Randomized Aldactone Evaluation Study, spironolactone was shown to produce the greatest survival benefit in patients with a serum procollagen type III amino-terminal peptide (PIIINP) level O 3.85 mcg/L. Whether procollagen peptides differ by NYHA functional class is unknown. We sought to compare serum procollagen peptide levels by NYHA functional class in order to determine if spironolactone might be of benefit to patients with less severe heart failure. Methods: Blood samples were collected from 74 spironolactone-naı¨ve patients with chronic, stable heart failure and left ventricular systolic dysfunction. Serum procollagen levels [PIIINP, procollagen type I amino-terminal peptide (PINP), and type I collagen telopeptide (ICTP)] were determined in duplicate by radioimmunoassay. Demographics, clinical characteristics, and procollagen peptides were compared by NYHA functional class. Results: The distribution of patients by NYHA functional class is shown in the table. The majority of patients were African American (73%) and had nonischemic cardiomyopathy (70%). Medication use included an ACE inhibitor or angiotensin receptor blocker (100%), b-blocker (93%), digoxin (68%), and diuretics (84%). Demographic characteristics, medical history, vasodilator therapy, and EF were similar between groups. There were no significant differences in procollagen levels between functional classes (table). Over 50% of patients in each group had a PIIINP O 3.85 mg/L. Conclusion: We found that markers of cardiac fibrosis are similar among patients with different NYHA functional classes. Our data suggest that patients with less severe symptoms of heart failure have similar degrees of cardiac fibrosis and may derive similar benefits from spironolactone, at least in terms of the drug’s effects on cardiac remodeling, as patients with more severe disease. Procollagens by Functional Class Procollagens (mg/L) PINP ICTP PIIINP
Class I (n 5 20)
Class II (n 5 19)
Class III/IV (n 5 32/3)
51 (33-72) 6.7 (5.4-9.8) 4.3 (3.2-5.3)
69 (43-88) 7.3 (5.9-17.0) 4.3 (2.9-7.2)
43 (34-68) 6.5 (4.9-12.2) 4.0 (2.6-5.9)
Median (interquartile range).
104 Matrix Metalloproteinases and Their Endogenous Inhibitors: Association with Ventricular Remodeling, Diastolic Dysfunction and Heart Failure in the Community Carolyn S. P. Lam1, Richard J. Rodeheffer1, John C. Burnett, Jr.1, Margaret M. Redfield1; 1Cardiovascular Diseases, Mayo Clinic and Foundation, Rochester, MN Left ventricular (LV) remodeling in cardiovascular disease (CVD) involves modulation of the extracellular matrix (ECM). Matrix metalloproteinases (MMPs) and their inhibitors (TIMPs) are key regulators of ECM homeostasis, can be detected in circulation, and represent potential markers of LV remodeling. However, data is conflicting regarding population norms and association of circulating levels with CVD, LV structure and LV function. We adressed these issues in this community-based study. Methods: Residents (age $ 45y, 44% male) of Olmsted County, MN (n 5 2042) underwent Doppler echocardiography and phlebotomy for MMP-9, TIMP-1 and BNP (all BiositeÒ assays). Based on 95th percentile cut-offs for relative wall thickness (RWT) and sex-specific LV mass index (LVMI) in normal controls, LV geometry was grouped as: normal (Nl); concentric remodeling (CR); concentric hypertrophy (CH); and eccentric hypertrophy (EH). LV diastolic function(DF) was graded as normal or progressively impaired according to an ordinal scale of 1-4. Results: In persons without CVD or obesity (n 5 623), MMP-9 was detectable in 99.3% (mean 2.45 6 5.02 ng/ml, range 0.17-112.49 ng/ml), while TIMP-1 was detectable in 64.2% (mean 794 6 933 ng/ml, range 300-6000 mg/ml). Levels were not related to age, sex or body mass index. MMP-9, but not TIMP-1, was higher in ever-smokers compared to non-smokers (p!0.001). In the entire population, both levels increased with hypertension (HTN) (p5!0.05) but not with diabetes, coronary artery disease or renal disease. MMP-9 alone was higher in heart failure (HF) (p50.01). Compared to Nl, TIMP-1 was increased in CR (p50.01) but unchanged in CH and EH; while MMP-9 was similar among groups. There was no correlation between MMP-9 or TIMP-1 and EF or DF grade. Conclusions: In this community-based study, circulating levels of MMP-9 and/or TIMP-1 were modestly associated with smoking, HTN and HF, but did not correlate well with LV geometry or function. Circulating levels of other members of the MMP/TIMP family or myocardial levels may parallel remodeling more closely. Circulating MMP-9 and TIMP-1 do not appear promising as markers of LV remodeling. Nl (n 5 1132)
CR (n 5 126)
CH (n 5 75)
EH (n 5 256)
Mean MMP-9, 2.54 6 4.41 2.42 6 2.04 2.41 6 1.60 2.52 6 1.96 ng/ml Mean TIMP-1, 801 6 881 1087 6 1139* 673 6 441 912 6 1040 ng/ml Mean BNP, 26.9 6 56.5 34.2 6 30.5 57.0 6 78.9* 50.4 6 80.5* pg/ml *p ! 0.05 vs Nl.
ANOVAp 0.72 !0.01 !0.01
102 Intra-Renal Infusion of BNP in Experimental Heart Failure: A Novel Strategy To Maximize the Renal Enhancing Actions of BNP While Minimizing Arterial Hypotension Horng H. Chen1, John A. Schirger1, Cataliotti Alessandro1, Fernando L. Martin1, John C. Burnett1; 1Internal Medicine, Cardiovsacular Diseases, Mayo Clinic College of Medicine, Rochester, MN Background: BNP possesses systemic vasodilating, renin-inhibiting and renal excretory and hemodynamic enhancing actions. However, the renal enhancing actions of BNP may be limited by arterial hypotension when administered intravenously (IV) at high doses. We hypothesized that intra-renal (IR) administration of BNP would maximize its renal actions without systemic hypotension. To test this hypothesis we utilized an innovative bilateral renal artery catheter system for direct renal delivery of BNP in a large animal model of congestive heart failure (CHF). Methods: We defined the cardiorenal and humoral effects of intravenous (IV) (n 5 6) or IR (n 5 6) administration of canine BNP at 0.01mg/kg/min for 45 minutes in two separate groups of dogs with pacing induced overt CHF (240 bpm for 10 days). We used a small (3.1 Fr) bifurcated renal catheter (Flowmedica) for direct infusion into the renal arteries. * P!0.05. Results: IR BNP resulted in natriuresis (4 6 2 to 50 6 11 mEq/min*), diuresis (0.2 6 0.1 to 16 0.3 ml/min*) with an increase in glomerular filtration rate (GFR: 26 6 6 to 38 6 5 ml/min*) and renal blood flow (RBF: 175 6 15 to 198 6 14 ml/min*) with suppression of plasma renin activity* and angiotensin II*. Importantly, IR BNP did not result in a decrease in mean artery blood pressure (MAP: from 98 6 2 to 99 6 1 mmHg PO0.05). These renal enhancing actions were associated with increased delivery of BNP to the kidney as evident by increased urinary BNP excretion (24 6 10 to 70 6 10 pg/min*) in association with a decrease in distal reabsorption of sodium, a nephron site abundant with natriuretic peptide receptors. In contrast, IV BNP significantly decreased MAP (from 100 6 3 to 91 6 5 mmHg*) with significantly reduced renal enhancing actions as compared to IR BNP. Conclusion: In overt experimental CHF, IR BNP maximized the renal enhancing actions of BNP in the absence of changes in MAP. Therefore IR BNP is a novel strategy to increase local delivery of BNP to the kidneys without the systemic side effects of arterial hypotension.
103 Serum Procollagen Peptides Are Similar in Mildly and Severely Symptomatic Patients with Heart Failure Vicki L. Groo1, Kathryn M. Momary1, Thomas D. Stamos2, Joseph R. Camp1, Larisa H. Cavallari1; 1Department of Pharmacy Practice, University of Illinois at Chicago, Chicago, IL; 2Division of Cardiology, University of Illinois at Chicago, Chicago, IL. Background: Spironolactone is an aldosterone antagonist that attenuates cardiac fibrosis and improves survival in patients with severe heart failure; however, its
benefits in less severe heart failure are unknown. In a subpopulation of the Randomized Aldactone Evaluation Study, spironolactone was shown to produce the greatest survival benefit in patients with a serum procollagen type III amino-terminal peptide (PIIINP) level O 3.85 mcg/L. Whether procollagen peptides differ by NYHA functional class is unknown. We sought to compare serum procollagen peptide levels by NYHA functional class in order to determine if spironolactone might be of benefit to patients with less severe heart failure. Methods: Blood samples were collected from 74 spironolactone-naı¨ve patients with chronic, stable heart failure and left ventricular systolic dysfunction. Serum procollagen levels [PIIINP, procollagen type I amino-terminal peptide (PINP), and type I collagen telopeptide (ICTP)] were determined in duplicate by radioimmunoassay. Demographics, clinical characteristics, and procollagen peptides were compared by NYHA functional class. Results: The distribution of patients by NYHA functional class is shown in the table. The majority of patients were African American (73%) and had nonischemic cardiomyopathy (70%). Medication use included an ACE inhibitor or angiotensin receptor blocker (100%), b-blocker (93%), digoxin (68%), and diuretics (84%). Demographic characteristics, medical history, vasodilator therapy, and EF were similar between groups. There were no significant differences in procollagen levels between functional classes (table). Over 50% of patients in each group had a PIIINP O 3.85 mg/L. Conclusion: We found that markers of cardiac fibrosis are similar among patients with different NYHA functional classes. Our data suggest that patients with less severe symptoms of heart failure have similar degrees of cardiac fibrosis and may derive similar benefits from spironolactone, at least in terms of the drug’s effects on cardiac remodeling, as patients with more severe disease. Procollagens by Functional Class Procollagens (mg/L) PINP ICTP PIIINP
Class I (n 5 20)
Class II (n 5 19)
Class III/IV (n 5 32/3)
51 (33-72) 6.7 (5.4-9.8) 4.3 (3.2-5.3)
69 (43-88) 7.3 (5.9-17.0) 4.3 (2.9-7.2)
43 (34-68) 6.5 (4.9-12.2) 4.0 (2.6-5.9)
Median (interquartile range).
104 Matrix Metalloproteinases and Their Endogenous Inhibitors: Association with Ventricular Remodeling, Diastolic Dysfunction and Heart Failure in the Community Carolyn S. P. Lam1, Richard J. Rodeheffer1, John C. Burnett, Jr.1, Margaret M. Redfield1; 1Cardiovascular Diseases, Mayo Clinic and Foundation, Rochester, MN Left ventricular (LV) remodeling in cardiovascular disease (CVD) involves modulation of the extracellular matrix (ECM). Matrix metalloproteinases (MMPs) and their inhibitors (TIMPs) are key regulators of ECM homeostasis, can be detected in circulation, and represent potential markers of LV remodeling. However, data is conflicting regarding population norms and association of circulating levels with CVD, LV structure and LV function. We adressed these issues in this community-based study. Methods: Residents (age $ 45y, 44% male) of Olmsted County, MN (n 5 2042) underwent Doppler echocardiography and phlebotomy for MMP-9, TIMP-1 and BNP (all BiositeÒ assays). Based on 95th percentile cut-offs for relative wall thickness (RWT) and sex-specific LV mass index (LVMI) in normal controls, LV geometry was grouped as: normal (Nl); concentric remodeling (CR); concentric hypertrophy (CH); and eccentric hypertrophy (EH). LV diastolic function(DF) was graded as normal or progressively impaired according to an ordinal scale of 1-4. Results: In persons without CVD or obesity (n 5 623), MMP-9 was detectable in 99.3% (mean 2.45 6 5.02 ng/ml, range 0.17-112.49 ng/ml), while TIMP-1 was detectable in 64.2% (mean 794 6 933 ng/ml, range 300-6000 mg/ml). Levels were not related to age, sex or body mass index. MMP-9, but not TIMP-1, was higher in ever-smokers compared to non-smokers (p!0.001). In the entire population, both levels increased with hypertension (HTN) (p5!0.05) but not with diabetes, coronary artery disease or renal disease. MMP-9 alone was higher in heart failure (HF) (p50.01). Compared to Nl, TIMP-1 was increased in CR (p50.01) but unchanged in CH and EH; while MMP-9 was similar among groups. There was no correlation between MMP-9 or TIMP-1 and EF or DF grade. Conclusions: In this community-based study, circulating levels of MMP-9 and/or TIMP-1 were modestly associated with smoking, HTN and HF, but did not correlate well with LV geometry or function. Circulating levels of other members of the MMP/TIMP family or myocardial levels may parallel remodeling more closely. Circulating MMP-9 and TIMP-1 do not appear promising as markers of LV remodeling. Nl (n 5 1132)
CR (n 5 126)
CH (n 5 75)
EH (n 5 256)
Mean MMP-9, 2.54 6 4.41 2.42 6 2.04 2.41 6 1.60 2.52 6 1.96 ng/ml Mean TIMP-1, 801 6 881 1087 6 1139* 673 6 441 912 6 1040 ng/ml Mean BNP, 26.9 6 56.5 34.2 6 30.5 57.0 6 78.9* 50.4 6 80.5* pg/ml *p ! 0.05 vs Nl.
ANOVAp 0.72 !0.01 !0.01