A new algorithm for the diagnosis of hypertension in Canada

A new algorithm for the diagnosis of hypertension in Canada

Context

Hypertension, or elevated blood pressure, affects an estimated 7.3 million Canadians.  One-third of the hypertensive population remains uncontrolled today, while 17% remain unaware that they have it. While it is the most common modifiable risk factor for death or disability in the world, when left untreated, it can lead to complications affecting numerous organ systems including the brain, heart, eyes, and kidneys.

Accurate blood pressure measurement is essential for proper diagnosis and treatment. A revised algorithm for the diagnosis of hypertension is being proposed by the members of the Canadian Hypertension Education Program (CHEP).

Objectives

The objective of this paper is to present evidence for a revised algorithm to diagnose hypertension. Two major deficiencies in the current diagnostic process must be discussed. Firstly, so-called ascultatory measurements, using a stethoscope and inflatable cuff and performed in routine clinical settings, have serious accuracy limitations that have not been overcome despite efforts to educate health care professionals over several years.

Secondly, recent data indicate that patients with white coat hypertension, a condition where blood pressure rises due to the stress of being in a clinical setting, must be identified earlier in the process and in a systematic manner rather than on a voluntary basis, so they are not unnecessarily treated with anti-hypertensive medications.

Results

This paper presented evidence for a revised algorithm to diagnose hypertension. Protocols for home blood pressure measurement and ambulatory blood pressure monitoring were reviewed.

The revised algorithm strongly encourages the use of validated electronic digital oscillometric devices, in addition to conducting out-of-office blood pressure measurements, preferably ambulatory or home, to confirm the diagnosis of hypertension.

Conclusion

Many patients in Canada are currently being misdiagnosed as hypertensive on the basis of elevated manual “routine” office blood pressure readings. In the real world setting of clinical practice, the majority of these readings are poorly performed using auscultatory techniques. Evidence supports the use of electronic oscillometric digital blood pressure measurements in the office setting and the need for out-of-office measurements by ambulatory blood pressure monitoring or a home blood pressure measurement diagnostic series in order to properly diagnose hypertension.

There is no evidence to support pharmacologic treatment in subjects with white coat hypertension at the present time; misdiagnosing such patients as hypertensive may have significant negative implications both at the individual and the health care system level.

Research by:  Mark Gelfer, MD, Lyne Cloutier, RN, PhDcorrespondenceemail, Stella S. Daskalopoulou, MD, PhD, Raj S. Padwal, MD, MSc, Maxime Lamarre-Cliche, MD, Peter Bolli, MD, Donna McLean, RN, NP, PhD, Alain Milot, MD, MSc, Sheldon W. Tobe, MD, MSc(HPTE), Guy Tremblay, MD, Donald W. McKay, PhD, Raymond Townsend, MD, Norm Campbell, MD

Published in the Canadian Journal of Cardiology