Boston ? A new study gives fresh evidence that many people with clogged heart arteries are being overtreated with stents, and that a simple blood-flow test might help prevent unnecessary care.

Fewer deaths, heart attacks and repeat procedures occurred when doctors implanted fewer of these tiny artery props, using the blood-flow test to decide when they were truly needed, the study found.

Results were published in today’s New England Journal of Medicine.

Several reports in recent years have suggested that stents and artery-opening angioplasty procedures were being overused in nonemergency cases, often without giving medicine alone a chance to work. Concern about stent complications also has made doctors more cautious about elective angioplasty.