Dofetilide in patients with left ventricular dysfunction and either heart failure or acute myocardial infarction: Rationale, design, and patient characteristics of the DIAMOND studies

BACKGROUND: Attempts to prolong life with antiarrhythmic drugs in patients at increased risk of sudden cardiac death have so far been disappointing or inconclusive. HYPOTHESIS: The Danish Investigations of Arrhythmia and Mortality ON Dofetilide (DIAMOND) encompass two survival studies testing the prophylactic use of the selective potassium-channel blocker, dofetilide, in patients at high risk of sudden death. METHODS: The first study includes patients admitted to hospital with congestive heart failure (CHF), the other includes patients with acute myocardial infarction (MI) within the previous 7 days. In both studies patients must have left ventricular systolic dysfunction (ejection fraction < or = 35%) determined by echocardiography. Each of the two studies are planned to enroll 1500 patients. Consecutive hospitalized patients with MI or CHF are screened in 37 Danish hospitals. Eligible patients are randomized to receive dofetilide or matching placebo. All patients are continuously monitored by telemetry for the first 3 days of the study to detect possible arrhythmic events and to ensure resuscitation in case of serious arrhythmias. Minimum duration of follow-up is 12 months. RESULTS: Between November 1993 and July 1996, a total of 5812 consecutive patients with CHF and 8688 consecutive patients with MI was screened for entry. Of these, 1518 patients were included in the CHF study and 1510 patients in the MI study. Overall 1-year mortality of randomized patients were 28 and 22%, respectively. CONCLUSION: DIAMOND will provide important data on the safety and efficacy of dofetilide in high-risk patients with left ventricular dysfunction and either CHF or MI, as well as evaluate tolerability in these populations.