CHICAGO — Two big studies offer good news to people with high blood pressure, finding that novel ways to use cheap drugs already on the market can lower their risk of heart attacks, stroke and death — even in the elderly.

Both studies were stopped early so the benefits could be made known. Doctors presented results Monday at an American College of Cardiology conference.

“It is never too late to start” on blood pressure drugs, said Dr. Nigel Beckett of Imperial College in London, who led one study in the elderly that also was published online by the New England Journal of Medicine.

More than 70 million Americans have high blood pressure — readings of 140 over 90 or more — and only a third have it well controlled by medicines. Guidelines advise starting on one, usually a “water pill,” and adding others as needed.

With each new medication, “You get more pills, more co-pays,” said Dr. Kenneth Jamerson of the University of Michigan. “Our idea is, if you have to add on, why not do two right off the bat” in a single pill.

He led a study testing a single daily pill combining a diuretic and the ACE inhibitor benazepril versus a daily pill containing benazepril and a calcium channel blocker, amlodipine. ACE inhibitors dilate blood vessels to lower pressure. Calcium channel blockers do the same in a different way.

A total of 11,462 people in the United States and Nordic countries were given one combo or the other. Their average age was 68, and besides high blood pressure they were obese, had diabetes or other health problems.

Neither they nor their doctors knew which drugs they were taking until the study was stopped in October after it was clear that people on the ACE-calcium blocker combo were doing better.

Those people had about 15 percent fewer heart-related problems or strokes — 531 among the 5,721 in this group versus 653 events among the 5,741 others, Jamerson said.

Six months of treatment with either combo brought blood pressure to an acceptable range for 73 percent of patients.

The study was paid for by Novartis, which sells Lotrel, the combo that proved better, and Jamerson consults for the company. The drugs are all sold as generics, although the doses in some require two pills a day instead of one.

A second study that found dramatic benefits for treating people in their 80s, an age when blood pressure drugs were not known to be safe or effective.

That study was stopped last July after monitors saw that those on the diuretic had 39 percent fewer fatal strokes and 21 percent fewer deaths from any cause, benefits far exceeding what researchers predicted.