Predicting cardiovascular risk using conventional vs ambulatory blood pressure in older patients with systolic hypertension. Systolic Hypertension in Europe Trial Investigators

JAMA. 1999 Aug 11;282(6):539-46. doi: 10.1001/jama.282.6.539.

Abstract

Context: The clinical use of ambulatory blood pressure (BP) monitoring requires further validation in prospective outcome studies.

Objective: To compare the prognostic significance of conventional and ambulatory BP measurement in older patients with isolated systolic hypertension.

Design: Substudy to the double-blind placebo-controlled Systolic Hypertension in Europe (Syst-Eur) Trial, started in October 1988 with follow up to February 1999. The conventional BP at randomization was the mean of 6 readings (2 measurements in the sitting position at 3 visits 1 month apart). The baseline ambulatory BP was recorded with a noninvasive intermittent technique.

Setting: Family practices and outpatient clinics at primary and secondary referral hospitals.

Participants: A total of 808 older (aged > or =60 years) patients whose untreated BP level on conventional measurement at baseline was 160 to 219 mm Hg systolic and less than 95 mm Hg diastolic.

Interventions: For the overall study, patients were randomized to nitrendipine (n = 415; 10-40 mg/d) with the possible addition of enalapril (5-20 mg/d) and/or hydrochlorothiazide (12.5-25.0 mg/d) or to matching placebos (n = 393).

Main outcome measures: Total and cardiovascular mortality, all cardiovascular end points, fatal and nonfatal stroke, and fatal and nonfatal cardiac end points.

Results: After adjusting for sex, age, previous cardiovascular complications, smoking, and residence in western Europe, a 10-mm Hg higher conventional systolic BP at randomization was not associated with a worse prognosis, whereas in the placebo group, a 10-mm Hg higher 24-hour BP was associated with an increased relative hazard rate (HR) of most outcome measures (eg, HR, 1.23 [95% confidence interval [CI], 1.00-1.50] for total mortality and 1.34 [95% CI, 1.03-1.75] for cardiovascular mortality). In the placebo group, the nighttime systolic BP (12 AM-6 AM) more accurately predicted end points than the daytime level. Cardiovascular risk increased with a higher night-to-day ratio of systolic BP independent of the 24-hour BP (10% increase in night-to-day ratio; HR for all cardiovascular end points, 1.41; 95% CI, 1.03-1.94). At randomization, the cardiovascular risk conferred by a conventional systolic BP of 160 mm Hg was similar to that associated with a 24-hour daytime or nighttime systolic BP of 142 mm Hg (95% CI, 128-156 mm Hg), 145 mm Hg (95% CI, 126-164 mm Hg) or 132 mm Hg (95% CI, 120-145 mm Hg), respectively. In the active treatment group, systolic BP at randomization did not significantly predict cardiovascular risk, regardless of the technique of BP measurement.

Conclusions: In untreated older patients with isolated systolic hypertension, ambulatory systolic BP was a significant predictor of cardiovascular risk over and above conventional BP.

Publication types

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

MeSH terms

  • Aged
  • Antihypertensive Agents / therapeutic use
  • Blood Pressure Determination / methods*
  • Blood Pressure Monitoring, Ambulatory
  • Cardiovascular Diseases / epidemiology*
  • Female
  • Humans
  • Hypertension / complications
  • Hypertension / diagnosis
  • Hypertension / drug therapy
  • Hypertension / physiopathology*
  • Male
  • Middle Aged
  • Prognosis
  • Randomized Controlled Trials as Topic
  • Reproducibility of Results
  • Risk Factors
  • Systole

Substances

  • Antihypertensive Agents