Cutting blood pressure below the currently recommended target can significantly reduce the rate of heart attacks, strokes, heart failure and deaths. The findings come from the largest study ever conducted to examine whether reducing systolic blood pressure below the currently recommended goal would be beneficial.

The study was stopped early when an analysis indicated the benefits were clear, officials said. "This is landmark study," says Dr. Gary Gibbons, director of the National Heart, Lung and Blood Institute, which sponsored the study. "We think that this study will clearly have an impact on patient care for those with hypertension."

"This is a very big deal," says Dr. Mark Creager, president of the American Heart Association and director of the Heart Vascular Center at the Dartmouth Hitchcock Medical Center in Lebanon, N.H. "I believe that this study will serve as a roadmap towards saving a significant number of lives."

About one-third of U.S. adults have high blood pressure, which is a major risk factor for a variety of health problems, including heart attacks, strokes and heart failure.

Currently, most guidelines recommend that high blood pressure patients reduce their systolic blood pressure, which cardiologists consider to be the more important of the two readings from a blood pressure measurement, to a maximum of 140 millimeters of mercury.

But there's been a big debate about whether lower systolic blood pressure might be even better.

NHLBI sponsored the SPRINT study beginning in 2009. Researchers recruited more than 9,300 adults with high blood pressure and at least one other risk factor for heart disease, such as being a smoker or having high cholesterol. Half of their doctors tried to get their systolic pressure down to 140. The other half shot for 120.

The study was supposed to continue until 2016, but it was stopped recently when a panel monitoring the results found in a preliminary analysis that it had already produced significant results: Reducing systolic blood pressure to 120 or lower reduced heart attacks, strokes and heart failure by almost a third and the risk of death by almost a quarter, Gibbons says.

Details about the findings haven't yet been published in a scientific journal, but will be, the researchers say. Gibbons, Creager and others said they expected the findings would lead to new guidelines for doctors. But doctors may act sooner.

"If we have a patient in our office tomorrow who fits the criteria of this trial it certainly doesn't seem too early to begin to lower our target to 120," says Dr. Mary Norine Walsh, medical director, heart failure and cardiac transplantation at the St. Vincent Heart Center of Indiana. She is also a vice president of the American College of Cardiology.

Still, it may be difficult for patients to hit the lower target. About half of those who have been diagnosed with high blood pressure fail to reach the current target of 140.

"We have a long way to go in improving public awareness about high blood pressure, making sure it's detected and appropriately treated," Creager says. "But studies such as this really reinforce that we need to take important steps to raise public awareness to make sure that [patients] are having conversations with their health care providers about how it can be effectively managed."