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ABPM Glossary
ABPM Glossary

About 33% of the US adult population has high blood pressure and about 37% of the US population 20 years of age and older is estimated to be pre-hypertensive. This leaves 30% or less Americans whose blood pressure falls within the normal and healthy range. The estimated direct and indirect cost of high blood pressure for 2008 is an astounding $69.4 billion.1

According to the Joint National Committee 72, the definitions of each stage of hypertension include:

 

 Systolic Diastolic
Normal <120 <80
Prehypertension 120–139 80–89
Stage 1 Hypertension 140-159 90-99
Stage 2 Hypertension ≥160≥100

Ambulatory Blood Pressure Monitoring (ABPM) provides a better estimate of mean blood pressure and blood pressure variability than in-office or home blood pressure methods by recording several blood pressure measurements throughout the day and night.

White-Coat Hypertension

“White-coat” hypertension describes when a patient’s blood pressure readings are significantly higher in the physician’s office while readings outside the office are lower and within the acceptable range.3,4,5 Centers for Medicaid and Medicare Services requires that “white-coat” hypertension cases meet the following criteria for U.S. reimbursement:

  • Clinic/office blood pressure reading greater than 140/90 on at least three separate visits with two measurements taken at each visit.
  • At least two blood pressure measurements less than 140/90 taken outside the clinic/office.
  • No evidence of end-organ damage.

Approximately 15-20% of stage 1 hypertension cases may be attributed to white-coat hypertension. Beneficial cost savings can be achieved when ABPM replaces antihypertensive treatment, with treatment costs as low as $300/year.6

Patients with white-coat hypertension are accepted to have less risk than those patients diagnosed as hypertensive. White-coat patients receive little benefit from antihypertensive treatment. While clinical blood pressure readings are generally lowered with treatment, ambulatory blood pressure changes insignificantly.3

Resistant Hypertension

Of those diagnosed with hypertension, 65% do not have it controlled.1 Resistant hypertension, sometimes called drug resistant hypertension, is defined as blood pressure that remains above normal on three or more antihypertensive medications.7,8 Patient characteristics associated with resistant hypertension include: older age, obesity, excessive salt intake, chronic kidney disease, and diabetes. The American Heart Association released a statement in April 2008 on the diagnosis, evaluation, and treatment of resistant hypertension, and called for more research so that his condition may be understood.8

Masked Hypertension

Masked hypertension is when a patient has normal clinic blood pressure readings, but high ambulatory blood pressure readings. In other words, masked hypertension is the opposite of white-coat hypertension. The occurrence of masked hypertension in the general population may be as high as ten percent, and it is generally associated with poor outcomes.3

Nocturnal Hypertension

Blood pressure typically dips during sleep and rises again as the body awakens. The general percentage dip is 10-20%, but recent studies have shown that absolute measurements are a better indicator for negative outcomes than the percentage dip due to limited reproducibility of dip percentage.9 Therefore, 24-hour ambulatory blood pressure studies provide important insight on the diurnal rhythm and variability of blood pressure.3

References

  1. Rosamond, W. et al. Heart Disease and Stroke Statistics 2008 Update: A Report from the American Heart Association Statistics Committee and Stroke Statistics Subcommittee. (2008). Circulation, 117, e25 – e 146.
  2. Chobanian, A.V., Bakris, G.L., Black, H.R., Cushman, W.C., Green, L.A., Izzo, J.L., Jones, D.W., Materson, B.J., Oparil, S., Wright, J.T., Roccella, E.J., and the National High Blood Pressure Education Program Coordinating Committtee. (2003). The Seventh Report of the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure: The JNC7 Report. Journal of the American Medical Association, 289(19),2560 – 2572.
  3. Pickering, T.G., Hall, J.E., Appel, L.J., Falkner, B.E., Graves, J., Hill, M.N., Jones, D.W., Kurtz, T., Sheps, S.G., and Roccella, E.J. (2004). Recommendations for Blood Pressure Measurement in Humans and Experimental Animals: Part 1: Blood Pressure Measurement in Humans: A Statement for Professionals from the Subcommittee of Professional and Public Education of the American Heart Association Council on High Blood Pressure Research. Hypertension, 45, 142-161.
  4. Verdecchia, P., Staessen, J.A., White, W.B., Imai, Y., and O’ Brien, E.T. (2002). Properly Defining White Coat Hypertension. European Heart Journal, 23, 106-109.
  5. William, W. B. (2006). Expanding the Use of Ambulatory Blood Pressure Monitoring for the Diagnosis and Management of Patients with Hypertension. Hypertension, 47, 14-15.
  6. Krakoff, L.R. (2006) Cost-Effectiveness of Ambulatory Blood Pressure. Hypertension, 47, 29-34.
  7. Trewet, C.L.B. and Ernst, M.E. (2008). Resistant Hypertension: Identifying Causes and Optimizing Treatment Regimens. Southern Medical Journal, 101(2), 166-173.
  8. Calhoun, D.A., Jones, D., Textor, S., Goff, D.C., Murphy, T.P., Toto, R.D., White, A., Cushman, W.C., White, W., Sica, D., Ferdinand, K., Giles, T.D., Falkner, B., and Cary, R.M. (2008). Resistant Hypertension: Diagnoisis, Evaluation, and Treatment: A Scientific Statement from the American Heart Association Professional Education Committee of the Council for High Blood Pressure Research. Hypertension, 51(6), 1403 – 1419.
  9. Boggia, J., Li, Y., Thijs, L., Hansen, T.W., Kikuya, M., Bjorklund-Bodegard, K., Richart, T., Ohkubo, T., Kuznetsova, T., Torp-Pedersen, C., Lind, L., Ibsen, H., Imai, Y., Wang, J., Sandoya, E., O’Brien, E., and Staessen, J.A. (2007). Prognostic accuracy of day versus night ambulatory blood pressure: a cohort study. The Lancet, 370, 1219-1229.