ABC World News Tonight broadcast a story last night, a portion of which is captured on their website, about patients' own stem cells used to build new blood vessels.

It is interesting clinical research, but the story offered only breathlessly optimistic projections -- no caveats, warnings, unknowns or uncertainties. An excerpt: "Results in more than 100 patients show that, within just three months after the stem cell injections, patients see a significant improvement in blood flow to the heart. The heart muscle itself actually doubles its ability to squeeze or contract.

The short-term results (3 months) send up one red flag. Another is the use of what are called surrogate endpoints. In other words, rather than reporting that people lived longer (which of course would be a pretty empty projection after only 3 months), they reported a different marker or endpoint to measure "success." That is, blood flow to the heart.

But the coup de grâce comes with the next line of the story: "Researchers say these adult stem cells might help tens of millions of heart patients each year."

Or, the story could be just as true to the facts and conclude, "Maybe not." The science behind this work holds great potential. It doesn't need hyping of short-term research measuring only surrogate endpoints that extrapolates these early findings to tens of millions of people.