title: Blood pressure, stroke, and coronary heart disease. Part 2, Short-term reductions in blood pressure: overview of randomised drug trials in their epidemiological context.
abstract: There are 14 unconfounded randomised trials of antihypertensive drugs (chiefly diuretics or beta-blockers): total 37,000 individuals, mean treatment duration 5 years, mean diastolic blood pressure (DBP) difference 5-6 mm Hg. In prospective observational studies, a long-term difference of 5-6 mm Hg in usual DBP is associated with about 35-40% less stroke and 20-25% less coronary heart disease (CHD). For those dying in the trials, the DBP difference had persisted only 2-3 years, yet an overview showed that vascular mortality was significantly reduced (2p less than 0.0002); non-vascular mortality appeared unchanged. Stroke was reduced by 42% SD 6 (95% confidence interval 35-50%; 289 vs 484 events, 2p less than 0.0001), suggesting that virtually all the epidemiologically expected stroke reduction appears rapidly. CHD was reduced by 14% SD 5 (95% CI 4-22%; 671 vs 771 events, 2p less than 0.01), suggesting that just over half the epidemiologically expected CHD reduction appears rapidly. Although this significant CHD reduction could well be worthwhile, its size remains indefinite for most circumstances (though beta-blockers after myocardial infarction are of substantial benefit). At present, therefore, a sufficiently high risk of stroke (perhaps because of age, blood pressure, or, in particular, history of cerebrovascular disease) may be the clearest indication for antihypertensive treatment.
authors.forename: R
authors.initials: R
authors.lastname: Collins
authors.forename: R
authors.initials: R
authors.lastname: Peto
authors.forename: S
authors.initials: S
authors.lastname: MacMahon
authors.forename: P
authors.initials: P
authors.lastname: Hebert
authors.forename: N H
authors.initials: NH
authors.lastname: Fiebach
authors.forename: K A
authors.initials: KA
authors.lastname: Eberlein
authors.forename: J
authors.initials: J
authors.lastname: Godwin
authors.forename: N
authors.initials: N
authors.lastname: Qizilbash
authors.forename: J O
authors.initials: JO
authors.lastname: Taylor
authors.forename: C H
authors.initials: CH
authors.lastname: Hennekens
mesh_terms: D000959:Antihypertensive Agents / Q000627:therapeutic use*; D015982:Bias; D001794:Blood Pressure / Q000187:drug effects*; D002423:Cause of Death; D002561:Cerebrovascular Disorders / Q000453:epidemiology / Q000401:mortality / Q000517:prevention & control*; D003327:Coronary Disease / Q000453:epidemiology / Q000401:mortality / Q000517:prevention & control*; D003971:Diastole / Q000187:drug effects; D004232:Diuretics / Q000627:therapeutic use; D006801:Humans; D006973:Hypertension / Q000188:drug therapy* / Q000453:epidemiology; D009203:Myocardial Infarction / Q000453:epidemiology / Q000401:mortality / Q000517:prevention & control; D016017:Odds Ratio; D016032:Randomized Controlled Trials as Topic; D012307:Risk Factors; D013997:Time Factors
chemical_list: D000959:Antihypertensive Agents; D004232:Diuretics