An Overview of the Expanded Definition and Classification of Hypertension Part 4/5

Clinical Characteristics and Practical Implications of the Proposed Hypertension Categories

A practical clinical interpretation of the revised hypertension categories is shown in Table 6.
Table 6. Clinical Characterization, BP Patterns, and Practical Implications of the Hypertension Algorithm

Hypertension Category	Clinical Characterization	BP Pattern	Practical Implications
Normal	Optimal BP levels	Resting BP levels usually < 120/80 mm Hg	Includes some patients identified as having prehypertension (based on JNC 7 criteria)
	No identifiable early markers of CVD	Occasional BP elevations, even to ≥ 140/90 mm Hg, may occur
Stage 1	Early CVD markers present	BP levels > 115/75 mm Hg	Earliest identifiable stage of hypertensive disease
	Frequently 1 or more CVD risk factors present	BP may be frankly elevated, particularly with environmental stress	Includes individuals with prehypertension (based on JNC 7 criteria) who also have CVD risk factors or early disease markers
	No evidence of target-organ damage
Stage 2	Diffuse disease markers present OR evidence (limited) of early target-organ damage	Sustained resting BP frequently ≥ 140/90 mm Hg, with much higher elevations induced by physiologic or psychologic stressors	Equivalent to JNC 7 stage 1 hypertension
			Indicates progressive disease
			Risk factors, if not attenuated, continue to contribute to progressive target-organ disease
Stage 3	Overt CVD present	Sustained resting BP levels ≥ 140/90 mm Hg usual (untreated or inadequately treated)	Equivalent to JNC 7 stage 2 hypertension
		Marked BP elevations to levels > 160/100 mm Hg not uncommon (untreated or inadequately treated)	Includes all individuals with clinical evidence of overt target-organ damage or CVD, or who have sustained a CVD event, regardless of BP levels

BP = blood pressure; CVD = cardiovascular disease; JNC 7 = Seventh Report of the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure
In the algorithm, individuals with optimal levels of BP and no identifiable early markers of CVD are categorized as normal. These individuals usually have resting BP levels of 120/80 mm Hg or lower, but BP may be elevated occasionally, even to levels of 140/90 mm Hg or higher.^[6] Given the limits of clinic BP measurements, home BP determinations or 24-hour ambulatory BP recordings may be helpful in identifying patients with more than occasional BP elevations, who may be categorized more appropriately as having stage 1 hypertension.^[16]Because the HWG algorithm does not recognize a prehypertension category, some individuals designated as having prehypertension according to the JNC 7 classification may be considered normal in the paradigm.
The earliest identifiable stage of hypertensive disease, stage 1 hypertension, is characterized by the presence of early CVD markers. Although BP levels are higher than 115/75 mm Hg and may be frankly elevated in patients at this stage, abnormal BP patterns -- including loss of nocturnal dipping, exaggerated responses to exercise or mental stress, and widened pulse pressure -- may provide clearer evidence of the presence of early hypertensive disease.^[4] Although patients should have more than 1 CV risk factor to be included in this category, they should not have any evidence of target-organ damage.
In contrast to stage 1, stage 2 hypertension is characterized by diffuse disease markers and evidence of progressive disease as a consequence of persistent functional and structural changes in BP control mechanisms and in the heart and vasculature. Although patients at this stage frequently have sustained elevations in resting BP levels of 140/90 mm Hg or higher -- with much higher elevations induced by physiologic or psychologic stress -- it is important to recognize that any individual with numerous disease markers or limited evidence of early target-organ damage, such as left ventricular hypertrophy, fits into this category, regardless of BP levels. Methods of detecting or measuring some of the early target-organ damage characteristic of this stage of hypertension are currently limited to specialized or research settings, and further evaluation is needed to determine their potential utility and cost-effectiveness in clinical settings.^[6] Nonetheless, aggressive management of CV risk factors that are identified in patients at this stage may help attenuate the progression of target-organ damage.
Finally, stage 3 hypertension is an advanced stage of the hypertensive continuum, characterized by the presence of overt CVD. Overt hypertensive target-organ disease is often pervasive, and CVD events may have already occurred. If inadequately treated or left untreated, individuals at this stage usually have sustained resting BP levels of 140/90 mm Hg or higher, although marked elevations to levels higher than 160/100 mm Hg are not uncommon.^[6] Regardless of BP levels, however, all individuals with clinical evidence of overt target-organ damage or CVD, as well as those who have already sustained CVD events, are included in this category. Reaching this phase means that damage to target organs, as well as overt cardiorenal disease, has already occurred. As a consequence, CV risk factor modification and treatment of target-organ disease and all identified CVD should be vigorous and sustained.[6