Neuroendocrine activation after myocardial infarction: causes and consequences

Cleland, John G.F.; Cowburn, Peter J.; Morgan, Kevin

doi:10.1136/hrt.76.3_suppl_3.53

“…This is consistent with findings in patients who have experienced small to moderate infarcts, in whom the renin\angiotensin\aldosterone system is activated only moderately and transiently, if at all [28]. This is consistent with findings in patients who have experienced small to moderate infarcts, in whom the renin\angiotensin\aldosterone system is activated only moderately and transiently, if at all [28].…”

Section: Discussionsupporting

confidence: 90%

Myocardial infarction with and without reperfusion in sheep: early cardiac and neurohumoral changes

Charles¹,

Elliott²,

Nicholls³

et al. 2000

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There are few stable and reproducible large-animal models of chronic heart failure produced by ischaemic damage to the myocardium. Here we characterize a novel method of inducing myocardial damage in closed-chest sheep by catheter delivery of thrombogenic coils, and compare this with a newly described open-artery model of cardiac injury in sheep. Sham controls were compared with animals subjected to (a) 90 min of coronary artery occlusion/reperfusion by PTCA (percutaneous transluminal coronary angioplasty) balloon, and (b) permanent coronary artery occlusion induced by catheter delivery of thrombogenic coils (seven sheep/group). Both balloon occlusion/reperfusion and permanent coil occlusion resulted in well-defined anteroapical infarcts, as documented by ECG changes, significant rises in creatine kinase (both groups P<0.001) and troponin-T (both groups P<0.05), and post-mortem examination. Washout of enzymes was much more rapid in the reperfused group (P<0. 01). Infarction resulted in significant reductions in left ventricular (LV) ejection fraction (both groups P<0.01) and regional wall abnormalities. Ejection fraction 7 days post-coil (21.3+/-4.2%) was significantly lower (P<0.01) than that 7 days post-balloon (38. 8+/-4.5%). Coil-induced infarction was associated with acutely reduced arterial pressure (P<0.05), and increases in heart rate (P<0. 05), atrial pressures (P<0.05), plasma brain natriuretic peptide levels (P<0.05) and adrenaline levels (P<0.05). Rises seen in plasma endothelin levels in sham controls were blunted in the coil group (P<0.001). Haemodynamic changes were less marked in the balloon group. In conclusion, restriction of coronary artery occlusion to 90 min results in infarction, but less LV dysfunction with reduced early remodelling, compared with permanent occlusion. Acute changes in biochemical markers, haemodynamics, neurohormones and LV function confirm that these are excellent models of open- and closed-artery myocardial infarction leading to asymptomatic LV dysfunction.

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“…This is consistent with findings in patients who have experienced small to moderate infarcts, in whom the renin\angiotensin\aldosterone system is activated only moderately and transiently, if at all [28]. Indeed, the rise in levels of natriuretic peptides may act to suppress any activation of the renin\angiotensin\ aldosterone system and contribute to compensation of early LV dysfunction.…”

Section: Discussionsupporting

confidence: 85%

Myocardial infarction with and without reperfusion in sheep: early cardiac and neurohumoral changes

Charles¹,

ELLIOTT²,

NICHOLLS³

et al. 2000

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There are few stable and reproducible large-animal models of chronic heart failure produced by ischaemic damage to the myocardium. Here we characterize a novel method of inducing myocardial damage in closed-chest sheep by catheter delivery of thrombogenic coils, and compare this with a newly described open-artery model of cardiac injury in sheep. Sham controls were compared with animals subjected to (a) 90 min of coronary artery occlusion/reperfusion by PTCA (percutaneous transluminal coronary angioplasty) balloon, and (b) permanent coronary artery occlusion induced by catheter delivery of thrombogenic coils (seven sheep/group). Both balloon occlusion/reperfusion and permanent coil occlusion resulted in well-defined anteroapical infarcts, as documented by ECG changes, significant rises in creatine kinase (both groups P<0.001) and troponin-T (both groups P<0.05), and post-mortem examination. Washout of enzymes was much more rapid in the reperfused group (P<0. 01). Infarction resulted in significant reductions in left ventricular (LV) ejection fraction (both groups P<0.01) and regional wall abnormalities. Ejection fraction 7 days post-coil (21.3+/-4.2%) was significantly lower (P<0.01) than that 7 days post-balloon (38. 8+/-4.5%). Coil-induced infarction was associated with acutely reduced arterial pressure (P<0.05), and increases in heart rate (P<0. 05), atrial pressures (P<0.05), plasma brain natriuretic peptide levels (P<0.05) and adrenaline levels (P<0.05). Rises seen in plasma endothelin levels in sham controls were blunted in the coil group (P<0.001). Haemodynamic changes were less marked in the balloon group. In conclusion, restriction of coronary artery occlusion to 90 min results in infarction, but less LV dysfunction with reduced early remodelling, compared with permanent occlusion. Acute changes in biochemical markers, haemodynamics, neurohormones and LV function confirm that these are excellent models of open- and closed-artery myocardial infarction leading to asymptomatic LV dysfunction.

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“…In patients with acute myocardial infarction, the presence of systolic dysfunction with decreased left ventricular ejection fraction is the major prognostic factor for cardiovascular mortality [10,17]. Although high plasma ANP was found to carry prognostic importance in univariate analysis in most of the studies in patients with acute myocardial infarction, the significance was lost when the ejection fraction was included in a Cox multivariate model in some studies [9][10][11]18] but not others [19][20][21].…”

Section: Discussionmentioning

confidence: 99%

Plasma brain natriuretic peptide — an independent predictor of cardiovascular mortality in acute heart failure

Yu

¹

,

Sanderson

²

1999

European J of Heart Fail

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Purpose: To examine the prognostic importance of both plasma atrial natriuretic and B-(brain natriuretic peptide) following an episode of acute heart failure. Subjects and methods: A prospective cohort of 91 patients admitted into hospital with acute heart failure were recruited. After initial in-hospital management plasma ANP and BNP levels were measured by radioimmunoassay, and echocardiography was performed on the same day. Patients were followed up for 12 months and the main outcome measure was cardiovascular death. Results: Plasma ANP and BNP levels were significantly higher in patients who died of a cardiovascular cause within 12 months (P < 0.001 and P < (1.0001, respectively) or at I-month (P < 0.05 and P < 0.001) after recruitment. By Kaplan-Meier estimated life-table curves, patients with above median plasma ANP or BNP levels had significantly higher I-year mortality (42.5% vs. 11.6%, both P < 0.005). By multivariate Cox proportional hazard regression analysis, the plasma BNP level was the most important prognostic factor predicting mortality (X 2 = 18.3, P < 0.0001), followed by age (X2 = 11.5, P < 0.001). Other factors mcluding ANP, left ventricular ejection fraction by M-mode echocardiography, pulmonary arterial pressure, sex, cause of heart failure as well as New York Heart Association class were not significant. Conclusion: A plasma BNP level has independent and at least short-term prognostic significance in patients admitted with acute heart failure. This non-invasive and readily available blood test should be considered for risk stratification in patients with acute heart failure.

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Neuroendocrine activation after myocardial infarction: causes and consequences

Cited by 14 publications

References 65 publications

Myocardial infarction with and without reperfusion in sheep: early cardiac and neurohumoral changes

Myocardial infarction with and without reperfusion in sheep: early cardiac and neurohumoral changes

Myocardial infarction with and without reperfusion in sheep: early cardiac and neurohumoral changes

Plasma brain natriuretic peptide — an independent predictor of cardiovascular mortality in acute heart failure

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