Both angiotensin-converting enzyme (ACE) inhibitors and angiotensin II-receptor blockers (ARBs) have been shown to be of benefit in patients with heart failure, and in patients who have reduced ventricular function following a myocardial infarction.  However, it is less well known whether they provide benefit in patients with ischaemic heart disease (IHD) and preserved ventricular function.  Therefore the Agency for Healthcare Research and Quality commissioned this report to review the evidence for the clinical effects and harms of using ACE inhibitors, ARBs, or combination therapy in patients with IHD who are already receiving standard therapy.
The authors reviewed 41 studies that met eligibility criteria.  7 trials, including a total of 32,559 participants, concluded that ACE inhibitors reduced the relative risk (RR) for death (RR, 0.87) and nonfatal myocardial infarction (RR, 0.83), but increased the risk of syncope and cough.  Low-strength evidence, suggested that ARBs reduce the RR for the composite endpoint of cardiovascular mortality, nonfatal myocardial infarction, or stroke (RR, 0.88).  Moderate-strength evidence showed no overall benefit of the use of combination therapy on the risk of total mortality or myocardial infarction, when compared to using ACE inhibitors alone.  Combination therapy did, however, lead to an increased risk of discontinuations due to hypotension (p<0.001) and syncope (p=0.035).
Conclusions:
ACE inhibitors reduce the risk of death, stroke, and myocardial infarction in patients with IHD and preserved ventricular function already on medical therapy; however there was little data to suggest that ARBs do so.  The use of both classes of drugs in combination increased the risk of hypotension and syncope, with no additional clinical benefit compared to using ACE inhibitors alone.
• Baker WL, Coleman CL, Kluger J et al.  Effectiveness of therapies for stable ischaemic heart disease.  Systematic Reviews: Comparative Effectiveness of Angiotensin-Converting Enzyme Inhibitors or Angiotensin II–Receptor Blockers for Ischemic Heart Disease.  Annals Internal Med 2009, Oct 19.  Epublication ahead of print.