A television advertisement for a heart stent that promotes the product's potential benefits but seems to play down the medical risks may deceive the public and should be reviewed by federal regulators, according to a commentary in The New England Journal of Medicine. The 60-second ad for the Cypher stent, made by the Cordis subsidiary of Johnson & Johnson, fails to warn consumers adequately about the potential dangers of receiving a stent, two cardiologists argued in the essay, to appear in next Thursday's issue but already available online.