Those people had about 20 percent fewer heart-related problems or strokes—526 among the 5,713 in this group versus 650 events among the 5,732 others, Jamerson said. Six months of treatment with either combo brought blood pressure to an acceptable range for 73 percent of patients.

The findings could shape treatment guidelines due to be reviewed in a few months.

Guidelines also may change to reflect 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. “The over-80s are the most rapidly expanding segment of our population,” and the prevalence of blood pressure rises as people age, Beckett noted.

His study assigned 3,845 older people in Europe, China and several other countries to take the diuretic indapamide or dummy pills plus the ACE inhibitor perindopril as needed to reach a goal of 150/80 from an average starting pressure of 173/91. The 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.