The study compared the use of two different combinations of blood pressure drugs to see if combination pills could help patients get better control of their hypertension.

While both pills helped control blood pressure, people who took the Novartis AG drug Lotrel -- a pill containing an angiotensin-converting enzyme, or ACE, inhibitor plus a calcium channel blocker -- had 20 percent fewer heart events such as heart attacks and strokes than those who took an ACE inhibitor and diuretic, or "water pill," combination.

He said the findings challenge current national guidelines for the treatment of high blood pressure, which call for patients who need medication to start out on a single pill, usually a diuretic, and to add other drugs only as needed.

Millions of Americans take medications for hypertension but do not achieve control of their blood pressure. Reducing blood pressure can cut the risk of stroke, heart attack, heart failure and other conditions.