OBJECTIVE: To evaluate the influence of a history of arterial hypertension on the efficacy of the angiotensin converting enzyme (ACE) inhibitor trandolapril in patients with acute myocardial infarction (AMI) and left ventricular dysfunction. METHODS: A retrospective analysis of data from the Trandolapril Cardiac Event (TRACE) study. The TRACE study was a randomized, double-blind, placebo-controlled study in which patients with an enzyme-verified AMI and ejection fraction < or = 35% were assigned randomly to be administered oral trandolapril or placebo 3-7 days after the infarction. Of 1749 patients who entered the study, 400 (23%) had a history of arterial hypertension. The mean follow-up time was 26 months. MAIN OUTCOME MEASURES: Mortality from any cause. Secondary endpoints were sudden death, cardiovascular mortality, reinfarction and development of severe heart failure. RESULTS: Of the patients in the hypertensive group, 173 (43%) died during follow-up, versus 500 (37%) in the normotensive group. Treatment with trandolapril resulted in a relative risk of death from any cause for the hypertensive group of 0.59 (96% confidence interval 0.44-0.80), versus 0.85 (0.72-1.02) for normotensive patients. In a multivariate analysis, treatment with trandolapril was associated with a reduction in mortality among patients with a history of hypertension (P = 0.03). CONCLUSION: In this retrospective analysis, ACE inhibition after AMI complicated with left ventricular dysfunction was of greater benefit to patients with a history of arterial hypertension. ACE inhibition might be of particular importance in this group of patients but further studies to establish the clinical impact are necessary.