The researchers suggest that thiazide diuretic drug combined with a "potassium-sparing" drug can reduce that risk of sudden cardiac death and total coronary mortality by 40 percent.
The Joint National Committee, under the direction of the National Heart, Lung, and Blood Institute, publishes clinical practice guidelines for hypertension and the new guidelines are expected in 2009.
"The recommendations can now be re-examined in light of these new findings," said John Oates, M.D., senior author of the study.
Oates said that thiazide diuretics effectively reduced blood pressure for many patients, but they are also known to deplete potassium.
During the study, the research team led by Oates examined data from controlled clinical trials that compared a thiazide diuretic/potassium-sparing (ENaC inhibitor) drug combination to placebo.
They generated new, previously unpublished data on sudden death in these trials, and then analyzed the results of the trials in a meta-analysis - a statistical evaluation of data combined from multiple trials.
The analysis revealed that total cardiac mortality and sudden cardiac death in elderly patients with hypertension taking the drug combination were reduced by 40 percent reduction compared with those receiving placebo.
"It was very striking," Oates said.
He added that potassium-sparing drugs might reduce coronary mortality through a mechanism unrelated to their prevention of potassium loss.
The study is published in the Journal of the American Society of Hypertension.