1. A pharmaceutical composition comprising: a) an amount of a carboxyalkylether of formula I wherein n and m independently are integers from 2 to 9; R1, R2, R3, and R4 independently are C1-C6alkyl; Y1 and Y2 independently are COOH and COOR5, where R5 is C1-C6 alkyl; or a pharmaceutically acceptable salt thereof; b) an amount of an antihypertensive agent or a pharmaceutically acceptable salt thereof; c) a pharmaceutically acceptable carrier or diluent. 2. A pharmaceutical composition of Claim 1 wherein said antihypertensive agent is selected from a calcium channel blocker, an ACE inhibitor, an alpha-blocker, a beta-blocker, a diuretic agent, angiotensin-II receptor antagonists, a renin inhibitor or aldesterone antagonist. 3. A pharmaceutical composition of Claim 2 wherein said antihypertensive agent is olmesartan, eplerenone, amlodipine or quinapril, or pharmaceutically acceptable salts thereof. 4. A pharmaceutical composition of Claim 3 comprising quinapril hydrochloride and 6,6'-oxybis (2,2-dimethylhexanoic acid) monocalcium. 5. A first pharmaceutical composition comprising an amount of an antihypertensive agent or a pharmaceutically acceptable salt thereof and a pharmaceutically acceptable carrier or diluent for use in combination with a second pharmaceutical composition comprising an amount of a carboxyalkylether of Claim 1 or a pharmaceutically acceptable salt thereof and a pharmaceutically acceptable carrier or diluent, for achieving an antihypertensive and/or cardiovascular effect in a mammal suffering from hypertension or at risk for a cardiovascular disease, which effects are greater than the sum of the antihypertensive effects achieved by administering said first and second pharmaceutical compositions separately. 6. Use of Claim 5 herein said antihypertensive agent is olmesartan, eplerenone, amlodipine or quinapril. 7. Use of Claim 6 wherein said second pharmaceutical composition comprises 6,6'-oxybis (2,2-dimethylhexanoic acid) monocalcium. 8. A first pharmaceutical composition comprising an amount of a compound of formula II wherein n and m are each an integer selected from 2, 3, 4, or 5, or a pharmaceutically acceptable salt thereof and a pharmaceutically acceptable carrier or diluent for use in combination with a second pharmaceutical composition comprising an amount of a carboxyalkylether or a pharmaceutically acceptable salt thereof and a pharmaceutically acceptable carrier or diluent for achieving an antihypertensive effect in a mammal suffering from hypertension, which effects are greater than the sum of the antihypertensive effects achieved by administering said first and second pharmaceutical compositions separately. 9. Use of Claim 8 wherein said antihypertensive agent is olmesartan, eplerenone, amlodipine or quinapril. 10. Use of Claim 10 wherein said first composition comprising 6,6'-oxybis (2,2-dimethylhexanoic acid) monocalcium. 11. A first pharmaceutical composition comprising an amount of a carboxyalkylether of Claim I or a pharmaceutically acceptable salt thereof and a pharmaceutically acceptable carrier or diluent for use in combination with a second pharmaceutical composition comprising an amount of an antihypertensive agent or a pharmaceutically acceptable salt thereof and a pharmaceutically acceptable carrier or diluent for managing cardiac risk in a mammal at risk of suffering an adverse cardiac event, which effect is greater than the sum of the cardiac risk management effects achieved by administering said first and second pharmaceutical compositions separately. 12. Use of Claim 11 wherein said antihypertensive agent is olmesartan, eplerenone, amlodipine or quinapril. 13. A composition of Claim 12 wherein said first composition comprising 6, 6'-oxybis (2,2-dimethylhexanoic acid) monocalcium. 14. A kit for achieving a therapeutic effect in a mammal comprising: a) an amount of a carboxyalkylether of formula I or a pharmaceutically acceptable salt thereof and a pharmaceutically acceptable carrier or diluent in a first unit dosage form; b) an amount of an antihypertensive agent or a pharmaceutically acceptable salt thereof and a pharmaceutically acceptable carrier or diluent in a second unit dosage form; and c) container means for containing said first and second dosage forms. 15. A kit of Claim 14 wherein said antihypertensive agent is olmesartan, eplerenone, amlodipine or quinapril. 16. A method for treating vascular diseases in a mammal comprising administering to a mammal in need of treatment an effective amount of a composition according to Claim 1.