A newer, more expensive drug that blocks the action of a heart-threatening protein is almost as effective as an older class of medications in preventing problems for people who have had heart attacks, but combining the two seems to do more harm than good, a major study finds.Both drugs act against angiotensin II, which causes the narrowing of blood vessels and raises blood pressure. The older class of drugs, available as lower-cost generic products, are called ACE inhibitors because they block the action of an enzyme that produces angiotensin II.
