Beneficial effects of selective HDL-raising gene transfer on survival, cardiac remodelling and cardiac function after myocardial infarction in mice

Abstract

Post-myocardial infarction (MI) ejection fraction is decreased in patients with low high-density lipoprotein (HDL) cholesterol levels, independent of the degree of coronary atherosclerosis. The objective of this study is to evaluate whether selective HDL-raising gene transfer exerts cardioprotective effects post MI. Gene transfer in C57BL/6 low-density lipoprotein receptor (LDLr) ^−/− mice was performed with the E1E3E4-deleted adenoviral vector AdA-I, inducing hepatocyte-specific expression of human apo A-I, or with the control vector Adnull. A ligation of the left anterior descending coronary artery was performed 2 weeks after transfer or saline injection. HDL cholesterol levels were persistently 1.5-times ( P<0.0001) higher in AdA-I mice compared with controls. Survival was increased ( P<0.01) in AdA-I MI mice compared with control MI mice during the 28-day follow-up period (hazard ratio for mortality 0.42; 95% confidence interval 0.24–0.76). Longitudinal morphometric analysis demonstrated attenuated infarct expansion and inhibition of left ventricular (LV) dilatation in AdA-I MI mice compared with controls. AdA-I transfer exerted immunomodulatory effects and increased neovascularisation in the infarct zone. Increased HDL after AdA-I transfer significantly improved systolic and diastolic cardiac function post MI, and led to a preservation of peripheral blood pressure. In conclusion, selective HDL-raising gene transfer may impede the development of heart failure.