The Brain Resuscitation Clinical Trial (BRCT) II was a double-masked, randomized, controlled clinical study of cardiopulmonary-cerebral resuscitation (CPCR) designed to test therapy for the amelioration of brain damage after cardiac arrest. Lidoflazine, a calcium entry blocker, was chosen for investigation because of its beneficial effects on postischemic encephalopathy in animals, its minimal cardiovascular depressant effects, and its protective actions in myocardial ischemia in patients. Twenty-four hospitals in eight countries participated. Over 4 years, 520 patients were recruited, of whom 4 were subsequently lost to follow-up. Patients' age averaged 63 years and 62% were men. Cardiac arrest occurred prior to hospitalization in 63%. All patients received basic and advanced life support until circulation was restored, and then standardized extracerebral organ support. After restoration of spontaneous circulation with normal blood pressure, patients who failed to awaken were randomly assigned to receive IV administration of either lidoflazine or placebo. In each patient, outcome was evaluated by cerebral performance during a 6-month follow-up period. Periodic safety monitoring was carried out to assure that no excess of mortality or complications occurred in the lidoflazine-treated group compared with the placebo-treated group.