At the last cardiology congress of the American Heart Association (AHA), new high-pressure guidelines were presented. Since then, values of 120/80 mmHg and above have been regarded as high in the USA.
As a result of the new guidelines, almost half of the US population (about 30 million more people) now have hypertension. The authors assume that the prevalence of hypertension will triple or double in young men and women in the next few years. However, only a small proportion will need antihypertensive drugs under the new directives.
Arterial hypertension is a decisive risk factor for the development of cardiovascular diseases. And it is being diagnosed more and more frequently and earlier, not least because of the Western way of life, characterized by obesity, junk food and lack of exercise. In recent decades, the US limit values have therefore been lowered further and further, most recently in 1993, and a new update was now under consideration. A commission founded in 2014, consisting of 21 members of 11 American professional societies, evaluated about one thousand studies over three years and came to the conclusion that the blood pressure of the Americans must be lowered more than before. The new guidelines were published in the journal Hypertension in November 2017.
Let's start from the bottom. The definition of normal blood pressure values does not change. Anything below 120/80 mmHg is healthy. However, the values previously classified as prehypertension from 120/80 mmHg are now already considered elevated. The authors explain that the term "prehypertension" does not do justice to the increased risk. After all, these values already increase the risk of a heart attack up to twice compared to people with normal blood pressure. Values above 130/80 mmHg now have grade 1 hypertension, anything above 140/90 mmHg is classified as grade 2 hypertension. Previously, the limits for grade 1 and 2 hypertension were 140/90 and 160/100 mmHg, respectively. According to the authors, many studies show that lowering blood pressure below these limits would bring a measurable benefit.
In addition to the limit values, the therapy recommendations have also been updated. Not surprisingly, people with "high" blood pressure should adjust their diet, lose weight and do more exercise. For patients with grade 1 hypertension and low cardiovascular risk, a lifestyle change is sufficient. Patients with a known cardiovascular event or a more than 10% increased risk of suffering a cardiovascular event in the next 10 years should additionally receive drug therapy.
Pharmacological therapy is always recommended from grade 2 hypertension. The therapy target for Grade 1 and Grade 2 hypertension as well as for older people is given with values less than 130/80 mmHg. The authors also recommend that patients with high blood pressure should initially start directly with two drugs.
The authors make it clear that blood pressure measurement with calibrated devices and at different times is decisive for diagnosing hypertension. In addition to the blood pressure measured in practice, the blood pressure measured by the patient at home is also relevant. This is how white coat hypertension (high values in practice, normal values at home) or the so-called hidden hypertension (normal values in practice, high values at home) can be discovered. However, the most accurate method continues to be 24-hour blood pressure measurement.
Sources:
1. Whelton, PK. et al. 2017 ACC/AHA/AAPA/ABC/ACPM/AGS/APhA/ASH/ASPC/NMA/PCNA Guideline for the Prevention, Detection, Evaluation, and Management of High Blood Pressure in Adults. A Report of the American College of Cardiology/American Heart Association Task Force on Clinical Practice Guidelines. Hypertension. 2017 Nov 13. pii: HYP.0000000000000066. doi: 10.1161/HYP.0000000000000066. [Epub ahead of print]