Ambulatory pressure monitoring in the assessment of antihypertensive therapy

Cardiovasc Drugs Ther. 1989 Jun:3 Suppl 1:303-11. doi: 10.1007/BF00148475.

Abstract

A low-cost, ambulatory blood-pressure monitor has been calibrated and validated against a random zero sphygmomanometer. The repeatability of ambulatory pressure recordings after a placebo month in 44 mild to moderate untreated hypertensives was assessed. Systolic blood pressure showed a mean difference over 1 month of 2.0 mmHg, with a standard deviation of differences of 9.3 mmHg. The diastolic blood pressure mean difference was 0.1 mmHg (SD = 6.3 mmHg). This variability was much less than for clinic readings (SD = 17.3 mmHg) or for single home pressure readings (SD = 19.7 mmHg). Using ambulatory monitoring to detect a drop in pressure of 8/5 mmHg with a power of 0.9, the number of subjects needed in a parallel group trial is reduced from 360 to 68, and in a crossover study from 88 to 16 subjects. The usefulness of ambulatory pressure monitoring is demonstrated in a placebo-controlled comparison of atenolol, nifedipine retard, or their combination in random order. Eleven subjects, 21-60 years, with initial average blood pressures of 166.5/104.7 mmHg, showed a reduction in pressure with atenolol 50 mg a day of 15.1/10.0 mmHg, with nifedipine retard 20 mg b.i.d. of 21.0/11.6 mmHg, and with atenolol 50 mg and nifedipine retard 20 mg once a day of 26.2/16.8 mmHg. Ambulatory monitoring of pressure improved the accuracy of the trial and demonstrated a reduction in the alerting response with atenolol.

Publication types

  • Clinical Trial
  • Randomized Controlled Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Ambulatory Care
  • Antihypertensive Agents / therapeutic use*
  • Atenolol / therapeutic use
  • Blood Pressure Monitors* / economics
  • Calibration
  • Drug Therapy, Combination
  • Female
  • Humans
  • Male
  • Middle Aged
  • Nifedipine / therapeutic use
  • Reproducibility of Results
  • Research Design

Substances

  • Antihypertensive Agents
  • Atenolol
  • Nifedipine