In a recent study, researchers at Trinity College Dublin advised caution when treating blood pressure in some older people.
Their study contrasts with recent advice from the US to attempt to aggressively lower blood pressure in all adults to targets of 120mmHg.
In a large randomized blood pressure trial led by the US, scientists demonstrated that lowering systolic blood pressure to levels of 120mmHg or less compared with 140mmHg or less in adults could strongly reduce death from heart failure and heart attacks.
That study was the Systolic Blood Pressure Intervention Trial (SPRINT).
That study also reported that common side effects of low blood pressure were not increased by aggressive treatment — even in people over 75 years old.
(The common side effects include falls, injuries, blackouts, and drops in blood pressure after standing.)
Because the current findings were clinically counter-intuitive, the TILDA team tested whether they held true outside of a trial setting.
The team focused on people in Ireland over 75 years.
They examined rates of falls, injuries, blackouts and excessive drops in standing blood pressure in those who met the criteria for the treatment proposed in SPRINT and were followed up with for 3½ years — the same time period as SPRINT.
The researchers reported starkly contrasting results:
Falls and blackouts were up to 500% higher than reported in SPRINT and drops in blood pressure on standing were almost double that reported in SPRINT.
Therefore, in people over 75 years, intensive lowering of blood pressure to 120mmHg could result in harm.
The TILDA researchers recommend that a better understanding of who, over 75 years, will or will not benefit, is necessary before the widespread adaptation of the SPRINT results.
The TILDA team is now assessing how best to determine which people may benefit from SPRINT, and which people are more at risk from aggressive blood pressure lowering.
While the benefits of lowering blood pressure are not in dispute, the researchers are highlighting to physicians that it is important to be cognizant of the fact that the trial was not powered for adverse events such as falls causing injury.
Physicians ought not to expect a similarly low rate of adverse events in clinical practice as was observed in the trial when lowering blood pressure in older people.
They suggest that the risks and benefits of lowering blood pressure should be individualized for each patient.
Other researchers suggest that their work and that of other groups have shown that low blood pressure and particularly drops in standing blood pressure are linked not only to falls, fractures and fall- and blackout-related injuries but also to depression and possibly other brain health disorders.
These outcomes can seriously impact on independence and quality of life.
They advise caution in applying the SPRINT recommendations to everyone over 75 years without a detailed assessment of an individual’s risk versus possible benefit until such a time as we can provide more clarity retreatment.
The first author of the journal article is the Research Fellow at TILDA, Dr Donal Sexton. Professor Rose Anne Kenny, founding Principal Investigator with TILDA, is the lead author of the journal article.
The findings are published in the Journal of the American Medical Association (JAMA Internal Medicine).
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Source: JAMA Internal Medicine.