Use of PDE III inhibitors for the reduction of heart size in mammals suffering from heart failure

1. A method for reducing heart size in a non-human animal suffering from dilated cardiomyopathy comprising:

administering to a non-human animal having dilated cardiomyopathy at least one medicament comprising a therapeutically effective amount of a phosphodiesterase type III (PDE III) inhibitor or a Ca 2+ -sensitizing agent for a period of at least 10 days to 100 days; and

reducing the relative mean vertebral heart sum (VHS) of the animal by 0.05 to 0.25 vertebrae in response to said administration of said at least one medicament to the animal;

wherein the PDE III inhibitor or Ca 2+ -sensitizing agent comprises pimobendan, and said administration of at least one medicament is free from administering pimobendan with a combination of furosemide, enalapril and digoxin.

2. The method according to claim 1 , wherein the non-human animal is a canine or feline.

3. The method according to claim 1 , wherein the non-human animal is a dog.

4. The method according to claim 1 , wherein the PDE III inhibitor or Ca 2+ -sensitizing agent is utilized in oral or parenteral form.

5. The method according to claim 1 , wherein the PDE III inhibitor or Ca 2+ -sensitizing agent is administered in a daily dose from 10 μg/kg to 10 mg/kg.

6. The method according to claim 1 , wherein the PDE III inhibitor or Ca 2+ -sensitizing agent is administered together with a medicament selected from the group consisting of a calcium channel blocker, an ACE inhibitor, a diuretic, aspirin, a beta blocker, an angiotensin II antagonist, and combinations thereof, wherein the ACE inhibitor is selected from the group consisting of omapatrilat, MDL100240, alacepril, benazepril, captopril, trandolaprilat, ceranapril, moexipril, quinaprilat and spirapril, and combinations thereof.

7. The method according to claim 6 , wherein the angiotensin II antagonist is selected from the group consisting of saralasin acetate, candesartan cilexetil, valsartan, candesartan, losartan potassium, eprosartan, irbesartan, tasosartan and telmisartan, and combinations thereof.

8. The method according to claim 1 , wherein the PDE III inhibitor or Ca 2+ -sensitizing agent is administered together with one or more medicaments selected from the group consisting of an ACE inhibitor, a diuretic, and a digitalis glycoside, wherein the ACE inhibitor is selected from the group consisting of omapatrilat, MDL100240, alacepril, benazepril, captopril, trandolaprilat, ceranapril, moexipril, quinaprilat and spirapril, and combinations thereof.

9. The method according to claim 1 , wherein the administration for the period of at least 10 days to 100 days is free of administering furosemide.

10. A method for reducing heart size in a non-human animal suffering from dilated cardiomyopathy comprising:

administering to a non-human animal having dilated cardiomyopathy at least one medicament comprising a therapeutically effective amount of a phosphodiesterase type III (PDE III) inhibitor or a Ca 2+ -sensitizing agent for a period of at least 10 days to 100 days; and

reducing the relative mean vertebral heart sum (VHS) of the animal by 0.05 to 0.25 vertebrae in response to said administration of said at least one medicament to the animal;

wherein the PDE III inhibitor or Ca 2+ -sensitizing agent is selected from the group consisting of pimobendan, levosimendan, amrinone, enoximone, piroximone, and combinations thereof, and said administration of at least one medicament is free from administering pimobendan with a combination of furosemide, enalapril and digoxin.

11. The method according to claim 10 , wherein the administration for the period of at least 10 days to 100 days is free of administering furosemide.

12. A method for reducing heart size in a non-human animal suffering from dilated cardiomyopathy comprising:

administering to a non-human animal having dilated cardiomyopathy at least one medicament comprising a therapeutically effective amount of a phosphodiesterase type III (PDE III) inhibitor or a Ca 2+ -sensitizing agent for a period of at least 10 days to 100 days, wherein the PDE III inhibitor or Ca 2+ -sensitizing agent comprises pimobendan, and said administration of at least one medicament is free from administering pimobendan with a combination of furosemide, enalapril and digoxin; and

measuring the relative mean vertebral heart sum (VHS) of the animal after said period of administration, wherein the VHS of the animal is reduced by 0.05 to 0.25 vertebrae in response to said administration of said at least one medicament to the animal.