HCPLive Network

Awaiting JNC-8, Revised Classification of Hypertension Offers Practical Pointers

Awaiting JNC-8, Revised Classification of Hypertension Offers Practical Pointers 

 

By Laura Brasseur

 

In anticipation of JNC-8 (Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure), the hypertension writing group (HWG), which offered a new definition of hypertension during the annual meeting of the American Society of Hypertension (ASH) and was discussed in this journal in July 2005, have now published the details of their new classification in the Journal of Clinical Hypertension (2005;7:505-512), refocusing their treatment goals.  

 

“Our classification amplifies the JNC 7 definition [Table 1],” write Thomas D. Giles, MD, president of ASH, and colleagues. “We afford even greater priority to risk factors and early markers of cardiovascular disease, target organ damage, and overt cardiovascular disease than to observed blood pressure patterns” (Table 2).

 

The HWG describes previously published blood pressure (BP) cut points as “a moving target,” tracing the history of the diagnostic criteria for hypertension from a pre-1984 diastolic BP of >105 mm Hg to the latest JNC 7 publication, which introduced the category of “prehypertension.”

 

HWG quarrels with the idea of “assigning an illness diagnosis” (ie, prehypertension) to persons who, although they have a BP level of 120-140/80-90 mm Hg, may actually be at low risk for cardiovascular disease (CVD). They advocate instead the “normal” and “hypertensive” categories based on patients’ cardiovascular (CV) risk profile.

 

Because risk factors for early CVD can exist before any predefined BP threshold has been crossed, they stress the following CV risk factors:

·Increasing age

·BP ³140/90 mm Hg

·Overweight/obesity (body mass index ³24)

·Abdominal obesity (waist circumference >40 in for men and >35 in for women)

·Dyslipidemia: low-density lipoprotein cholesterol ³130 mg/dL; high-density

   lipoprotein cholesterol <40 mg/dL for men and <50 mg/dL for women; triglycerides

   ³150 mg/dL

·Fasting blood glucose ³100 mg/dL, insulin resistance, or diabetes

·Smoking

·Family history of CVD at age <50 years in men or <60 years in women

·Sedentary lifestyle

·Elevated high-sensitivity C-reactive protein.

 

Physicians should also evaluate for early markers of CVD, including BP-related markers (ie, loss of nocturnal BP dipping, exaggerated BP response to exercise, salt sensitivity, and widened pulse pressure). Other early disease markers include physiologic alterations in the cardiac (eg, mild left ventricular hypertrophy), vascular (eg, coronary calcification), and renal (eg, microalbuminuria) systems, and hypertensive retinal changes.

 

“Defining hypertension as a complex cardiovascular disorder associated with, but not exclusively defined by, high BP levels is a transitional strategy that is intended to pave the way for further research and clinical investigations aimed at detecting and treating disease at an earlier phase,” the authors conclude.

 

Table 1. BP cut point classification: JNC 7 vs HWG

 

SBP, mm Hg   DBP, mm Hg  JNC 7                          HWG

<120                <80                  Normal                                    Normal

120-140           80-90               Prehypertension                       Normal or stage 1

140-160           90-100             Stage 1                         Stage 1 or stage 2

>160                >100                Stage 2                         Stage 3

 

HWG = Hypertension Writing Group; SBP = systolic blood pressure; DBP = diastolic blood pressure.

 

 

Table 2. The new classification of hypertension

 

                                                            CV risk           Early CV        Target-organ

Classification  BP and CVD                  factors            markers         disease

Normal                        Normal BP or rare BP  None                None                None

                        Elevations

                        No identifiable CVD

 

Stage 1             Occasional/intermittent            ³1                    0-1                   None

hypertension    BP elevations

                        or

                        Risk factors/markers

                        suggesting early CVD

 

Stage 2             Sustained BP elevation            Multiple           ³2                    Early signs

hypertension    or

                        Evidence of

                        progressive CVD

 

Stage 3             Marked and sustained  Multiple           ³2 with            Overt, with or

hypertension    BP elevations                                       evidence of      without CV events

                        or                                                         CVD               

                        Evidence of advanced

                        CVD

 

CV = cardiovascular; BP = blood pressure; CVD = cardiovascular disease.

Further Reading
Proper blood pressure monitoring is a matter of life and death for patients diagnosed with hypertension. For many patients, treatment cost and complex testing regimens can make proper adherence a challenge.
Deaths from heart disease are dropping, but deaths related to hypertension and arrhythmias are on the rise, according to a new government study. The study was published in the Nov. 19 issue of the Journal of the American Medical Association, a cardiovascular disease theme issue. Findings were released early to coincide with presentation at the annual meeting of the American Heart Association, held from Nov. 15 to 19 in Chicago.
The most common cause of sudden cardiac death in young people is hypertrophic cardiomyopathy, an inherited condition that can lead to heart failure, angina, arrhythmia and sudden cardiac death. There is no medical treatment shown to halt or reverse the progression of the disease—just palliative care or surgery.
More Reading
$related2$