Boston Scientific, based in Natick, MA, is enrolling patients now in a trial for a new kind of drug-eluding coronary stent it calls Synergy. What makes it different from previous versions is that it is coated with a biodegradable polymer and drug formulation that will reduce reclogging more quickly than other stents. Then, it will disappear harmlessly, leaving only the metal stent in the vessel. The trial is expected to enroll 291 patients in Europe, Australia and New Zealand. Synergy is an investigational device in the United States. Boston Scientific's previous-generation Promus stent was approved in Europe late last year. Release