Angiotensin-converting enzyme (ACE) inhibitors are used after acute myocardial infarction (AMI) to reduce the incidence of congestive heart failure and mortality. The strength of this observation has not been evaluated clearly in patients with diabetes. Gottlieb and associates prospectively evaluated ACE-inhibitor treatment after AMI in patients with diabetes and patients without diabetes who were treated with usual care. Participants were classified as having diabetes or not, and then treated with ACE inhibitors or not. The primary outcome—mortality rate at 30 days and one year—was determined for more than 94 percent of the participants.

All-cause mortality was higher among the 533 patients with diabetes, and diabetes was identified as an independent risk factor for one-year all-cause mortality. Use of an ACE inhibitor in the hospital was an independent predictor of better outcome. Subgroup analysis of patients with diabetes demonstrated particular benefit among the sickest subgroups, including patients with hypertension, anterior AMI, or tachycardia on admission. Of the 1,646 patients without diabetes, almost one half received ACE inhibitors. ACE inhibitors again imparted a mortality benefit, most significant in patients with previous AMI or anterior AMI, in patients who were older than 70 years, and in those who were not treated with beta blockers. The strength of the benefit was higher in patients with diabetes than it was in patients without diabetes in most subgroups.

The authors conclude that ACE-inhibitor therapy following AMI is beneficial, especially among the sickest patients, such as those with diabetes who have hypertension or anterior AMI. Studies also have demonstrated other values of ACE-inhibitor therapy for patients with diabetes, including a lowered risk of diabetic retinopathy and nephropathy. Clearly, the high-risk population of post-AMI patients, with or without diabetes, would benefit from ACE-inhibitor therapy.