title: Cardiovascular protection and blood pressure reduction: a meta-analysis.
abstract: BACKGROUND
  Whether antihypertensive drugs offer cardiovascular protection beyond blood pressure lowering has not been established. We aimed to investigate whether pharmacological properties of antihypertensive drugs or reduction of systolic pressure accounted for cardiovascular outcome in hypertensive or high-risk patients.
  
  
  METHODS
  In a meta-analysis we extracted summary statistics from published reports, and calculated pooled odds ratios for experimental versus reference treatment. We correlated across-trials odd ratios for differences in systolic pressure between groups.
  
  
  RESULTS
  We analysed nine randomised trials comparing treatments in 62605 hypertensive patients. Compared with old drugs (diuretics and b-blockers), calcium-channel blockers and angiotensin converting-enzyme inhibitors offered similar overall cardiovascular protection, but calcium-channel blockers provided more reduction in the risk of stroke (13.5%, 95% CI 1.3-24.2, p=0.03) and less reduction in the risk of myocardial infarction (19.2%, 3.5-37.3, p=0.01). Heterogeneity was significant between trials because of high risk of cardiovascular events on doxazosin in one trial, and high risk of stroke on captopril in another; but systolic pressure differed between groups in these two trials by 2-3 mm Hg. Similar systolic differences occurred in a trial of diltiazem versus old drugs, and in three trials of converting-enzyme inhibitor against placebo in high-risk patients. Meta-regression across 27 trials (136124 patients) showed that odds ratios could be explained by achieved differences in systolic pressure.
  
  
  CONCLUSIONS
  Our findings emphasise that blood pressure control is important. All antihypertensive drugs have similar long-term efficacy and safety. Calcium-channel blockers might be especially effective in stroke prevention. We did not find that converting-enzyme inhibitors or a-blockers affect cardiovascular prognosis beyond their antihypertensive effects.
authors.affiliation: Studiecoördinatiecentrum, Hypertensie en Cardiovasculaire Revalidatie Eenheid, Departement Moleculair en Cardiovasculair Onderzoek, Katholieke Universiteit Leuven, Leuven, Belgium. jan.staessen@med.kuleuven.ac.be
authors.forename: J A
authors.initials: JA
authors.lastname: Staessen
authors.forename: J G
authors.initials: JG
authors.lastname: Wang
authors.forename: L
authors.initials: L
authors.lastname: Thijs
mesh_terms: D000368:Aged; D000959:Antihypertensive Agents / Q000627:therapeutic use*; D001794:Blood Pressure / Q000187:drug effects; D002318:Cardiovascular Diseases / Q000401:mortality / Q000517:prevention & control; D005260:Female; D006801:Humans; D006973:Hypertension / Q000188:drug therapy*; D008297:Male; D008875:Middle Aged; D016032:Randomized Controlled Trials as Topic
chemical_list: D000959:Antihypertensive Agents