Effects of the calcium sensitizer OR-1896, a metabolite of levosimendan, on post-infarct heart failure and cardiac remodelling in diabetic Goto-Kakizaki rats.

<bold>Background and Purpose: </bold>Levosimendan is a novel, short half-life calcium sensitizer used as pharmacological inotropic support in acute decompensated heart failure. After oral administration, levosimendan is metabolized to OR-1855, which, in rats, is further metabolized into OR-1896. OR-1896 is a long-lasting metabolite of levosimendan sharing the pharmacological properties of the parent compound.<bold>Experimental Approach: </bold>Effects of oral OR-1896 treatment on post-infarct heart failure and cardiac remodelling were assessed in diabetic Goto-Kakizaki (GK) rats, an animal model of type II diabetes. Myocardial infarction (MI) was produced to GK rats by coronary ligation. Twenty-four hours after MI or sham operation, the rats were randomized into four groups: (i) MI; (ii) MI + OR-1896 treatment; (iii) sham; and (iv) sham + OR-1896. Cardiac function and markers of cardiac remodelling were assessed 1, 4 and 12 weeks after MI.<bold>Key Results: </bold>OR-1896 increased ejection fraction and fractional shortening in GK rats with MI. OR-1896 ameliorated post-infarct cardiac hypertrophy, and prevented the MI-induced increase in cardiac mRNA for atrial natriuretic peptide, monocyte chemoattractant protein-1 and connective tissue growth factor, markers of pressure/volume overload, inflammation and fibrosis respectively. OR-1896 also suppressed mRNA for senescence-associated p16(INK4A) and p19(ARF). The beneficial effects of OR-1896 were more prominent at week 12 than at week 4. OR-1896 did not influence systolic blood pressure, blood glucose level, myocardial infarct size or cardiovascular mortality.<bold>Conclusions and Implications: </bold>Oral treatment with calcium sensitizer OR-1896 protects against post-infarct heart failure and cardiac remodelling in experimental model of type II diabetes. [ABSTRACT FROM AUTHOR]