There are five major therapeutic groups for possible evaluation in the ISIS 5 trial. They include intravenous beta-blocking agents, glucose-insulin-potassium (GIK) therapy, newer anticoagulant and antithrombotic agents (hirudin and Hirulog), newer thrombolytic drugs such as recombinant plasminogen activator (r-PA) and surfactant and emulsifying agents such as Rheothrx. Many pilot studies are underway. Selection of agents will depend on the scientific interest of collaborating hospitals as well as the agent's safety and efficacy.