A new study has found that lowering blood pressure to a rate far less than the standard could help cut deaths and heart failure.
The promising results come with risks, but experts say the study findings could warrant the review of current treatment guidelines for possible changes.
Hypertension is highly common in American adults, particularly among those aged 60 years old and above. Experts hypothesize that lowering systolic blood pressure may decrease clinical events. Systolic blood pressure is the top number in a blood pressure reading and pertains to the pressure in the arteries when the heart beats.
In the new study from the Systolic Blood Pressure Intervention Trial (SPRINT) research group, the authors presented the results of their intervention, which compared the benefits of one treatment, which targeted a systolic blood pressure of less than 120 mm Hg, and another, which targeted less than 140 mm Hg.
The participants were at least 50 years old; had a systolic blood pressure of 130 to 180 mm Hg; and had an elevated risk of developing cardiovascular events. They were randomly assigned to two groups: the standard-treatment group, which aimed to achieve a systolic blood pressure of 140 mm Hg, and the intensive-treatment group, which targeted a systolic blood pressure of 120 mm Hg. In total, the study had 9,361 participants.
The subjects were checked monthly for the first three months and every three months thereafter. The classes of drugs used on the subjects included calcium channel blockers, angiotensin receptor blockers and angiotensin-converting-enzyme (ACE) inhibitors.
The findings showed that targeting a systolic blood pressure of 120 mm Hg for hypertensive adults without diabetes led to notable drops in fatal and nonfatal cardiovascular events and death due to any cause, compared to when the standard 140 mm Hg was followed. More specifically, the intensive-treatment group had a 25 percent lower relative risk of the primary outcome compared to the standard-treatment group.
Serious adverse effects, however, were noted in 1,793 study subjects in the intensive-treatment group (38.3 percent) and in 1,736 participants in the standard-treatment group (37.1 percent). Adverse effects include hypotension episodes, fainting, electrolyte impairment and acute kidney injury.
"The results of SPRINT add substantially to the evidence of benefits of lowering systolic blood pressure, especially in older patients with hypertension," the authors wrote.
The findings could also raise critical practical concerns. One example is the difficulty of achieving a blood pressure of less than 140/90 mm Hg in the United States, with only 50 percent of the population able to attain the said rate. Changing current treatment guidelines according to the results of the new study would mean more demanding and more time-consuming efforts both from patients and health care providers.
The study was published in The New England Journal of Medicine on Monday, Nov. 9.
