Age-related differences in postinfarct left ventricular rupture and remodeling
Yining Yang1, Yitong Ma, Wei Han
1Cardiovascular Research Institute, Xinjiang Medical University, Xinjinag, China.
American Journal of Physiology. Heart and Circulatory Physiology
|February 12, 2008
Summary
Elderly patients face higher cardiac rupture risk after heart attack. Aged mice showed increased rupture, severe left ventricular remodeling, and inflammation, driven by elevated MMP-9 and blood pressure.
Area of Science:
- Cardiovascular Science
- Gerontology
- Pathology
Background:
- Cardiac rupture is a serious complication of acute myocardial infarction (MI), particularly in elderly individuals.
- The underlying mechanisms contributing to the higher incidence of cardiac rupture in older patients remain poorly understood.
- Investigating age-related differences in cardiac response to MI is crucial for understanding post-MI complications.
Purpose of the Study:
- To compare the incidence of cardiac rupture and early left ventricular (LV) remodeling after MI between aged and young mice.
- To explore the molecular and cellular mechanisms responsible for age-related differences in post-MI cardiac rupture and LV remodeling.
Main Methods:
- Coronary artery ligation was performed in old (12-month) and young (3-month) C57Bl/6 male mice to induce myocardial infarction (MI).
- Cardiac rupture incidence, infarct size, LV chamber dimensions, function, and blood pressure were assessed.
- Myocardial collagen content, inflammatory cell infiltration (macrophages, neutrophils), inflammatory cytokine mRNA expression, and matrix metalloproteinase (MMP)-9 activity were analyzed.
Main Results:
- The incidence of cardiac rupture within one week post-MI was significantly higher in old mice (40.7%) compared to young mice (18.3%).
- Old mice exhibited more severe LV chamber dilatation, impaired LV function, and higher blood pressure at day 7 post-MI.
- Aged mice showed increased collagen content, greater infiltration of macrophages and neutrophils, elevated inflammatory cytokine expression, and enhanced MMP-9 activity in the infarcted myocardium at day 3 post-MI.
Conclusions:
- Older age is associated with a significantly higher risk of cardiac rupture and more severe LV remodeling following acute MI, despite similar infarct sizes.
- Enhanced inflammatory response, increased MMP-9 activity, and elevated blood pressure are key factors contributing to the heightened risk of cardiac rupture and adverse LV remodeling in aged hearts post-MI.
