(CNN) There's good news in a National Institutes of Health study for Americans over 50 suffering from high blood pressure -- keep the pressure below 120 to reduce your risk of heart attack and stroke.
The NIH was so eager to get the news out that it decided to stop the study early, evaluate the preliminary results and make recommendations to doctors.
Researchers followed 9,300 people over the age of 50 who had high blood pressure. Part of the group received medication to adjust their blood pressure to the current guidance for a top number below 140, another group took medication to cut the top number to below 120. The top, or systolic, number measures pressure in the arteries when the heart muscle contracts.
Preliminary results showed a third fewer cardiac events such as heart attack, stroke, and heart failure and a quarter fewer deaths in those with the lower blood pressure, according to the NIH.
The study group was diverse and included men, women, minorities and elderly patients, with chronic kidney disease or a high risk of heart disease. There there were no patients with diabetes, prior stroke or polycystic kidney disease, the NIH said.
The systolic blood pressure intervention trial study "provides potentially lifesaving information that will be useful to health care providers as they consider the best treatment options for some of their patients, particularly those over the age of 50," said Doctor Gary H. Gibbons, director of the National Heart, Lung, and Blood Institute, which was a major sponsor of the trial.
In a statement, he called it an important milestone, but the NIH cautions health care providers not to change the way patients are treated yet, because the findings are preliminary and still require a peer review and publication, which is expected in the next few months.
Doctors don't know much yet about possible side effects when patients take more medication to lower their blood pressure.
"Getting patients to less than 120 is challenging," said Dr. George Thomas, director of the Cleveland Clinic's Center for Blood Pressure Disorders. When patients need multiple medications there may be a risk of falls or other complications, he said.
About a third of U.S. adults suffer from high blood pressure, or hypertension, a leading risk factor for heart disease, stroke, kidney failure, and other health problems.