Is the new BP guideline good for Asians?
Whether the 2017 ACC/AHA* blood pressure (BP) guidelines should be adopted in Asian countries was the topic of a much-anticipated discussion here at the Asian Pacific Society of Cardiology (APSC) Congress 2018 in Taiwan last week.
With the release of the new BP guideline, more people are immediately labelled as “hypertensive” since the BP threshold for hypertension diagnosis has been lowered to ≥130/80 mm Hg, said Professor Peera Buranakitjaroen from Siriraj Hospital in Bangkok, Thailand. “In the US for example, the number of hypertensive patients increased from 32 percent to 48 percent [with the new BP definition].” [APSC 2018, session S022-03]
In addition, those with a systolic BP of 140 mm Hg, previously the hypertension diagnostic cut-off in the JNC7 guideline, are now considered as having stage 2 hypertension under the new classification. The new BP threshold for drug treatment of hypertension is also lower now, noted Buranakitjaroen. [J Am Coll Cardiol 2018;71:2199-2269]
However, implementing the new BP guideline will bring about some issues. With more people being labelled as hypertensive and requiring treatment, more drugs are needed to further lower their BP, according to Buranakitjaroen.
Also, many more elderly will have serious adverse events (SAEs) from intensive BP lowering, since certain conditions that predispose one to develop SAEs are also more common in the elderly, including comorbidites (such as stroke, chronic kidney disease, and coronary artery disease), white coat effect, autonomic nervous system dysfunction, pill burden, and frailty.
“Huge budget will be needed to cope with such demand [from implementation of the new guidelines], while we have not [yet] done well in terms of prevention, early detection, and treatment of hypertension including BP control to target using the present guidelines,” said Buranakitjaroen.
“[Therefore,] the 2017 ACC/AHA guidelines should not be adopted immediately in Asian countries. While we await more clinical data, our limited resources should be used efficiently to improve the rate of awareness, detection, and treatment to target BP across the country using our own guidelines,” he stated.
As of present, the recommended BP threshold for hypertension diagnosis remains at <140/90 mm Hg in the national guideline by Thai Hypertension Society, except for certain subgroups of population, according to Buranakitjaroen. Subgroups which are exceptions to the rule include very elderly patients (age >80 years) who are recommended a BP threshold of <150/90 mm Hg; nonelderly patients (age <50 years), BP <130/80 mm Hg; and CKD patients with micro- and macro-albuminuria, BP <130/80 mm Hg.
Noting that less than 2 percent of the study population in SPRINT** — which the 2017 ACC/AHA BP guidelines are largely based on — are Asians, to project the guideline on the Asian population in the absence of data presents a unique challenge, commented Dr Eugene Yang of the University of Washington, Seattle, Washington, US, who is also a member of the ACC Cardiovascular Prevention Council and Official Reviewer for the new BP guideline.
When asked about how the Asian communities tackle the issue and derive the guidelines for their respective countries, Buranakitjaroen said the current national Thai recommendations are based on consensus expert opinion from different subspecialties.
“In the Philippines, we are creating a position statement on the 2017 BP guidelines,” added Session Chair Dr Jorge Sison of Makati Medical Center, Manila, the Philippines. He explained that in real-world clinical practice in the country, BP readings are mostly based on office BP measurement, although they are also beginning to emphasize on home BP monitoring now. As such, the position statement emphasizes two levels of recommendations — a threshold of 140/90 mm Hg for office BP and 130/80 mm Hg for home BP monitoring.