Low diastolic blood pressure puts patients at greater risk

While blood pressure drugs have been successful at pushing patient’s systolic blood pressure down to 120—the recognized benchmark for a healthy blood pressure—they have also dropped diastolic blood pressure to potentially dangerous levels.

Researchers at Johns Hopkins Medical Center in Baltimore have evidence suggesting that driving diastolic blood pressure too low will damage heart tissue.

"Our key finding suggests that for some patients, there should perhaps be modification of intensive anti-hypertensive treatment recommendations issued last year as a result of the SPRINT trial, and that physicians shouldn't look at driving down the top blood pressure number in isolation without considering implications of lowering the bottom number,” J. William Envoy, assistant professor of medicine and member of the Ciccarone Center for the Prevention of Heart Disease at the Johns Hopkins University School of Medicine, said in a statement.

The 2015 SPRINT trial showed protective cardiovascular benefits in patients who were placed on drugs to get high blood pressure down to 120/80.

Johns Hopkins began the study because there were some prior indications that patients with low diastolic blood pressure may suffer from inadequate pumping pressure through the coronary arteries.

Researchers followed 11,565 patients for 21 years over a series of five visits the last of which occurred in 2013. Each visit included blood pressure measurement, and several included blood testing.

The results showed that 1,087 patients with a diastolic blood pressure between 60 and 69 mm of mercury were 52 percent more likely to have heart damage. Those with a diastolic blood pressure between 70 to 99 mm of mercury showed no greater risk of heart damage.

Of those patients with a diastolic blood pressure under 60 mm of mercury, 165 had coronary heart disease events, 56 had strokes and 345 people died. Overall, those with the lowest diastolic blood pressure were nearly half (49 percent) more likely to have heart disease and 32 percent more likely to die of any cause.