Large British study shows no outcome benefit, more adverse events
Antihypertensive treatment for lower-risk patients with mild hypertension was associated with more adverse events but no better outcomes in a longitudinal cohort study.
Among treatment-naive people with a blood pressure in the 140/90 to 159/99 mm Hg range and no history of cardiovascular disease or risk factors for it, overall mortality during was 4.08% (95% CI 3.80%-4.37%) among those who didn't start on antihypertensives and 4.49% (95% CI 4.20%-4.80%) among those who did during 5.8 years of follow-up.
That 2% excess risk with treatment wasn't significant, but there were significant increased risks of hypotension, syncope, electrolyte abnormalities, and acute kidney injury, reported James Sheppard, PhD, of University of Oxford in England, and colleagues, in JAMA Internal Medicine
There was also no evidence of a relationship when looking at antihypertensive treatment and cardiovascular disease (HR 1.09, 95% CI 0.95-1.25).
The 2017 national guidelines recommend pharmacologic intervention starting at 130/80 mm Hg for high-risk patients and for all individuals regardless of risk with a blood pressure of 140/90 mm Hg or higher.
However, "these recommendations are considered to be controversial particularly with regard to treatment of people with low CVD risk and mild hypertension (ie, sustained blood pressure of 140/90-159/99 mm Hg), for whom there is a lack of clinical trial evidence to support initiation of pharmacologic treatment," the researchers wrote.
Sheppard and colleagues used the Clinical Practice Research Datalink electronic health record database, which is a representative sample of the U.K. population.
The investigators assessed 19,143 patients with an antihypertensive prescription after diagnosis, (mean age of 55 years, 56% women, 56% white) along with an equal number of matched untreated patients. During the 5.8 year follow-up period, 1,641 died.
Antihypertensive treatment was linked with an increased risk of adverse outcomes:
- Hypotension: HR 1.69 (95% CI 1.30-2.20) with a number needed to harm at 10 years (NNH10) of 41
- Syncope: HR 1.28 (95% CI 1.10-1.50) with a NNH10 of 35
- Electrolyte abnormalities: HR 1.72 (95% CI 1.12-2.65) with a NNH10 of 111
- Acute kidney injury: HR 1.37 (95% CI 1.00-1.88) with a NNH10 of 91
In commenting on the study, Robert Carey, MD, of University of Virginia Health System in Charlottesville, cautioned about some of the limitations of the observational findings.
"There is no indication as to whether the prescriptions were filled, whether the patients were adherent to the regimen, whether the regimen was effective in lowering blood pressure and whether there was any attempt to up-titrate the medications to achieve a blood pressure target," Carey told MedPage Today.
Even so, the researchers concluded: "Such data may be subject to bias from unmeasured confounding but suggest that caution should be exercised when considering treatment in this population."
This study was supported by a Medical Research Council Strategic Skills Postdoctoral Fellowship, the National Institute for Health Research (NIHR), Care Oxford at Oxford Health National Health Service Foundation Trust, the NIHR Oxford Biomedical Research Centre, NIHR Oxford Diagnostic Evidence Cooperative, and Harris Manchester College.
Sheppard did not report any disclosures.
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JAMA Internal Medicine
Source Reference: Sheppard J, et al “Benefits and harms of antihypertensive treatment in low-risk patients with mild hypertension” JAMA Intern Med 2018; DOI: 10.1001/jamainternmed.2018.4684.
Read the original article on Medpage Today: Low Clinical Utility Seen in Treating Low-Risk, Mild HTN