Stop me if you’ve heard this before. There’s a controversy over blood pressure targets. Some argue for 140/90 mm Hg, others for 130/80 mm Hg, and some super ambitious folks think that we should aim for 120/80 mm Hg. If this sounds familiar, it should. We did it in 2017. It’s unclear what, if anything, we learned from the experience. On the upside, it’s not as bad as it was 100 years ago.
When high blood pressure was a ‘good’ thing
Back then, many believed that you needed higher blood pressure as you got older to push the blood through your progressively stiffened and hardened arteries. Hence the name “essential” hypertension. The concern was that lowering blood pressure would hypoperfuse your organs and be dangerous. In the 1930s, John Hay told an audience at a British Medical Association lecture: “The greatest danger to a man with high blood pressure lies in its discovery, because then some fool is certain to try and reduce it.”
The 1900s were a simpler time when people had fatal strokes in their 50s, and their families were consoled by the knowledge that they had lived a good life.
If our thinking around blood pressure had evolved slightly faster, perhaps President Roosevelt wouldn’t have died of a stroke during World War II as his doctors watched his systolic blood pressure climb above 200 mm Hg and suggested massages and barbiturates to take the edge off.
The current controversy
Not that long ago, 180 mm Hg was considered mild hypertension. Now, we are arguing about a systolic blood pressure of 140 versus 130 mm Hg.
The American Academy of Family Physicians takes the view that 140/90 mm Hg is good enough for most people. Their most recent clinical practice guideline, based primarily on two 2020 Cochrane Reviews of blood pressure targets in patients with and without cardiovascular disease, did not find any mortality benefit for a lower blood pressure threshold.
This puts the AAFP guideline in conflict with the 2017 guideline issued jointly by the American College of Cardiology, American Heart Association, and nine other groups, which recommended a target of 130/80 mm Hg for pretty much everyone. Though they say greater than 140/90 mm Hg should be the threshold for low-risk patients or for starting therapy post stroke, we often forget those nuances. The main point of contention is that the AAFP guideline was looking for a mortality benefit, whereas the ACC/AHA/everyone else guideline was looking at preventing cardiovascular events. The latter guideline was driven mainly by the results of the SPRINT trial. ACC/AHA argue for more aggressive targets to prevent the things that cardiologists care about, namely heart attacks.
The AAFP guideline conceded that more aggressive control will result in fewer myocardial infarctions but warn that it comes with more adverse events. Treating 1,000 patients to this lower target would theoretically prevent four MIs, possibly prevent three strokes, but result in 30 adverse events.
In the end, what we are seeing here is not so much a debate over the evidence as a debate over priorities. Interventions that don’t improve mortality can be questioned in terms of their cost effectiveness. But you probably don’t want to have a heart attack (even a nonfatal one). And you certainly don’t want to have a stroke. However, lower blood pressure targets inevitably require more medications. Notwithstanding the economic costs, the dangers of polypharmacy, medication interactions, side effects, and syncope leading to falls cannot be ignored. Falls are not benign adverse events, especially in older adults.
The counter argument is that physicians are human and often let things slide. Set the target at 140/90 mm Hg, and many physicians won’t jump on a systolic blood pressure of 144 mm Hg. Set the target at 130 mm Hg, and maybe they’ll be more likely to react. There’s a fine line between permissiveness and complacency.
If you zoom out and look at the multitude of blood pressure guidelines, you start to notice an important fact. There is not much daylight between them. There are subtle differences in what constitutes high risk and different definitions of older (older should be defined as 10 years older than the reader’s current age). But otherwise, the blood pressure targets are not that different.
Does that final 10 mm Hg really matter when barriers to care mean that tens of millions in the United States are unaware they have hypertension? Even among those diagnosed, many are either untreated or inadequately treated.
With this context, perhaps the most insightful thing that can be said about the blood pressure guideline controversy is that it’s not all that controversial. We can likely all agree that we need to be better at treating hypertension and that creative solutions to reach underserved communities are necessary.
Arguing about 140/90 mm Hg or 130/80 mm Hg is less important than acknowledging that we should be aggressive in screening for and treating hypertension. We should acknowledge that beyond a certain point any cardiovascular benefit comes at the cost of hypotension and side effects. That tipping point will be different for different groups, and probably at a higher set point in older patients.
Individualizing care isn’t difficult. We do it all the time. We just shouldn’t be letting people walk around with untreated hypertension. It’s not the 1900s anymore.
Dr. Labos is a cardiologist at Hôpital Notre-Dame, Montreal. He reported no conflicts of interest.
A version of this article first appeared on Medscape.com.