Objective: To study the relationship between presence or absence of ischaemic events on Holter monitoring and occurrence of a hard or hard+soft endpoint.
Design: A randomized double-blind parallel group study of atenolol, nifedipine and their combination, with ambulatory monitoring off-treatment and after 6 weeks of randomized treatment and prospective follow-up of 2 years on average.
Setting: Europe.
Subjects: 682 men and women with a diagnosis of chronic stable angina and who were not being considered for surgery.
Main outcome: Hard endpoints were cardiac death, nonfatal myocardial infarction and unstable angina; soft endpoints were coronary artery bypass surgery, coronary angioplasty and treatment failure.
Results: The study showed no evidence of an association between the presence, frequency or total duration of ischaemic events on Holter monitoring, either on or off treatment, and the main outcome measures. There was a non-significant trend to a lower rate of hard endpoints in the group receiving combination therapy. Compliance, as measured by withdrawal from trial medication, was clearly poorest in the nifedipine group with similar withdrawal rates in the atenolol and combination therapy groups.
Conclusion: The recording of ischaemic events in 48 h Holter monitoring failed to predict hard or hard+soft endpoints in patients with chronic stable angina.