Changes in the hypertension guidelines would mean that millions will have elevated blood pressure, which experts say may pose greater risks.
The American College of Cardiology and American Heart Association published its new guidelines, essentially lowering the scale for high blood pressure.
Individuals with 130/80 mm Hg reading are considered hypertensive as opposed to the previous 140/90 requirement. The ACC and AHA reported that the lowering of scale is to allow early detection of complications that can occur even when the patient is not yet hypertensive.
"The 2017 ACC/AHA hypertension guideline has the potential to increase hypertension awareness, encourage lifestyle modification and focus antihypertensive medication initiation and intensification on US adults with high CVD risk," said Dr. Paul Muntner and his team in an analysis paper published in November 2017.
The new guidelines determined the normal blood pressure at 120/80 mm Hg, while elevated is between 120-129/80 (with the diastolic less than 80). Stage 1 hypertension is read between 130-139/80-89, while Stage 2 is at least 140/90.
A hypertensive crisis, which needs emergency room services, is at 180/120 and above.
The 2003 guidelines categorized 140/90 as stage 1, where the patient may be required to take anti-hypertensive drugs along with lifestyle changes. In the updated recommendations, it has been classified as a more severe hypertension requiring medication, which may include ACE inhibitors, angiotensin-2 receptor blockers, diuretics, and beta-blockers.
About 95 percent or 81.9 million of the 103.3 million American adults diagnosed with hypertension were recommended with antihypertensive drugs, according to the 2017 ACC/AHA guideline.
What the new numbers mean is that people who previously were not diagnosed with hypertension may have the condition now. This means that up to 79 percent of men aged 55 years and older are now classified as hypertensive.
Females aged 65 to 74 years have a higher prevalence of high blood pressure compared to men of the same age at 63.9 and 70.8 percent, respectively, according to NHANES data from 2007 to 2010.
Dr. Paul Conlin, an endocrinologist at VA Boston Healthcare System and Brigham and Women's Hospital, said guidelines are often changed once new evidence shows that the latter has become obsolete.
The Systolic Blood Pressure Intervention Trial published last year reported that reducing the systolic pressure of 130 to 120 could be more effective in preventing stroke, heart attacks, or cardiovascular failure as compared to when blood pressure is lowered from 140.
The revised blood pressure guidelines have become controversial despite its intent to allow patients be screened for cardiovascular risks. In an editorial published April 16 in JAMA Internal Medicine, Dr. Katy Bell cited critics who are concerned with the recent changes.
The Clinical Guidelines Committee of the American College of Physicians cited lack of evidence in lowering thresholds for hypertension that could "result in low-value care."
Similarly, the American Academy for Family Physicians raised concerns about possible adverse events of treating patients to a lower blood pressure due to the lack of assessments.
"Labeling a person as having hypertension increases their risk of anxiety and depression, as compared to the risk for people with the same blood pressure who aren't labeled as hypertensive. Second, it means more people may experience serious adverse effects from treatments," reported Dr. Bell.