Action: a 30,000 patient-years double-blind, placebo-controlled trial of nifedipine GITS in stable angina. ACTION Research Group.

To assess the overall balance between efficacy and safety of the long-action calcium antagonist nifedipine gastrointestinal therapeutic system (GITS) in patients with stable symptomatic coronary artery disease (CAD), a large multicentre placebo-controlled double-blind trial called ACTION has been mounted (A Coronary Disease Trial Investigating Outcome with Nifedipine GITS). Patients are eligible if they have proven CAD on antianginal treatment in stable clinical condition for at least 3 months without heart failure. The left ventricular ejection fraction must be above 40%. Patients not already on lipid-lowering therapy will be evaluated and such treatment will be started based on current guidelines before randomisation. After washout of an already given calcium antagonist, more than 6000 patients in total will be randomised in equal proportions to either nifedipine GITS 60 mg once daily or placebo. The mean clinical follow-up will be 5 years, with no restrictions on concomitant medication (with the exception of digitalis, calcium antagonists and class III antiarrhythmics). The primary end-point will be survival free of major cardiovascular events (i.e. survival free of acute myocardial infarction, emergency coronary angiography, overt heart failure, stroke and peripheral revascularisation). The study has 95% power to detect a significant (p < 0.05) 18% improvement of this end-point and is of sufficient size to exclude an excess mortality of 3.1 per 1000 patient-years. In this first stable angina trial of this size and scope, 185 centres in Canada, Europe, Israel, Australia and New Zealand will participate. Recruitment will start in November 1996 and is planned to be completed in 2 years.