SPRINT Trial Data Suggest We Should Be Aiming For Lower Blood Pressure Goals

Would you rather have a systolic blood pressure (BP)  of 120 mm Hg or 140 mm Hg?

Prior to a week ago this sometimes skeptical cardiologist thought treating hypertensive patients to the lower BP didn’t necessarily help  avoid death from cardiovascular disease, heart attacks or strokes and that it resulted in more side effects.

Clinical trials have shown that treatment of hypertension reduces the risk of cardiovascular disease outcomes, including stroke (by 35 to 40%), heart attacks (by 15 to 25%), and heart failure (by up to 64%) but the target for systolic blood-pressure lowering has been uncertain.

I wrote in “Home Versus Office Blood Pressure and the “Landmark” NIH Blood Pressure Trial” about the somewhat premature announcement of the SPRINT NIH trial on blood pressure previously.

With the recent  publication of the SPRINT trial data (A Randomized Trial of Intensive versus Standard Blood-Pressure Control — NEJM.) there is now impressive evidence supporting the lower target BP and apparently with minimal side effects.

The SPRINT trial randomized almost ten thousand patients and compared the effects of antihypertensive treatment with a systolic blood pressure (SBP) target of <120 mm Hg (intensive treatment) versus <140 mm Hg (standard treatment).

They studied hypertensive adults ≥50 years of age who had an average SBP of 130–180 mm Hg (the acceptable upper limit decreasing as the number of pretrial antihypertensive medications increased) and were at additional risk for cardiovascular disease (CVD).SPRINT was designed to recruit study participants with an average CVD risk of ≈2% per year, equivalent to a Framingham 10-year CVD risk score of 20%.

To understand if these trial results apply to you it is important to know what patients were enrolled in the study (inclusion and exclusion criteria) and I’ve listed these at the end of this post.

The SPRINT trial found that cardiovascular events like stroke and heart attack and death from these cardiovascular causes was lower by 25% in those patients treated intensively.  Overall death was lower by 27%

Average systolic blood pressure was 121 mm HG in the intensive therapy group and 134 mm Hg in the standard therapy group.

Drugs used were: thiazide-type diuretics, calcium channels blockers, and angiotensin-converting enzyme inhibitors or angiotensin receptor blockers. Other agents, including spironolactone, amiloride, β-blockers, vasodilators, or α-receptor blockers, could be added if necessary. On average, 2.8 drugs were used in the lower BP group versus 1.8 in the higher BP group.

This more intensive BP treatment was surprisingly well tolerated. Very surprisingly, orthostatic hypotension, (drop in BP on standing I talked about in my post on burpees and dizziness) was significantly more common in the standard than in the intensive arm. I would have expected this opposite.

There were  significantly more kidney problems and electrolyte abnormalities in the intensive group compared to the standard therapy group.

This study provides a very powerful argument for shooting for a BP of 120 in many of my patients.

And the skeptical cardiologist (who splits BP pills )will be aiming for a lower BP in himself.

It’s important to replicate how BP was measured in the SPRINT trial if we are to apply the results. As the authors have written elsewhere:

“be mindful of the manner in which BP was measured in the trial: an average of 3 office BP readings taken with proper cuff size, participants seated with their back supported, 5 minutes of rest before measurement, and no conversation during the rest period or BP determinations. In SPRINT, this was achieved using an automated manometer (Omron Healthcare, Lake Forest, IL) that was preset to wait for 5 minutes before measurement, as well as to take and average the 3 readings. BP measurements taken without observing these conditions are likely to overestimate BP6 and result in over treatment, with the potential for higher rates of serious adverse effects and greater utilization of resources.”

Pressurelessly Yours

-ACP

And the entry criteria:

 Increased cardiovascular risk was defined by one or more of the following: clinical or subclinical cardiovascular disease other than stroke; chronic kidney disease, excluding polycystic kidney disease, with an estimated glomerular filtration rate (eGFR) of 20 to less than 60 ml per minute per 1.73 m2 of body-surface area, calculated with the use of the four-variable Modification of Diet in Renal Disease equation; a 10-year risk of cardiovascular disease of 15% or greater on the basis of the Framingham risk score; or an age of 75 years or older. Patients with diabetes mellitus or prior stroke were excluded

4 thoughts on “SPRINT Trial Data Suggest We Should Be Aiming For Lower Blood Pressure Goals”

  1. Your third paragraph lists percentages that show changes in relative risk. It would be interesting if you interpreted the trial results in terms of absolute risk. The results would seem less impressive I suspect.

    It would also be interesting to see the individual results of the different medications. Beta blockers, calcium channel blockers, ARBs, ACEIs, and diuretics have quite different effects from each other. Do they uniformly change that relative risk across the board?

    1. Just looking at death rates over 3.3 years. Intensive treatment was 3.3% versus 4.5% for standard treatment, a difference of 1.2%.
      The number needed to treat (NNT) to prevent a death is 90.
      Does this seem less impressive?
      I’m always looking for better ways to communicate risks and benefits of treatment approaches but I’m not sure this is the best way to explain things.
      They haven’t broken it down by med type that I am aware of.

      1. It seems to me that to be impressive is largely what relative risk/benefit figures are reserved for. Absolutes come closer to reality.
        Having stepped into illnesses that I had much less a chance of succumbing to than 1.2%, I can tell you that it’s deep and dark there – whatever the chance.
        So, I am still fairly impressed with a 1.2% difference benefit. As you are, I’ll be looking into my own BP.

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